GNU Linux-libre 6.9.1-gnu
[releases.git] / drivers / i2c / busses / i2c-mlxbf.c
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  Mellanox BlueField I2C bus driver
4  *
5  *  Copyright (C) 2020 Mellanox Technologies, Ltd.
6  */
7
8 #include <linux/acpi.h>
9 #include <linux/bitfield.h>
10 #include <linux/delay.h>
11 #include <linux/err.h>
12 #include <linux/interrupt.h>
13 #include <linux/i2c.h>
14 #include <linux/io.h>
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/mutex.h>
18 #include <linux/of.h>
19 #include <linux/platform_device.h>
20 #include <linux/string.h>
21
22 /* Defines what functionality is present. */
23 #define MLXBF_I2C_FUNC_SMBUS_BLOCK \
24         (I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL)
25
26 #define MLXBF_I2C_FUNC_SMBUS_DEFAULT \
27         (I2C_FUNC_SMBUS_BYTE      | I2C_FUNC_SMBUS_BYTE_DATA | \
28          I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_I2C_BLOCK | \
29          I2C_FUNC_SMBUS_PROC_CALL)
30
31 #define MLXBF_I2C_FUNC_ALL \
32         (MLXBF_I2C_FUNC_SMBUS_DEFAULT | MLXBF_I2C_FUNC_SMBUS_BLOCK | \
33          I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SLAVE)
34
35 /* Shared resources info in BlueField platforms. */
36
37 #define MLXBF_I2C_COALESCE_TYU_ADDR    0x02801300
38 #define MLXBF_I2C_COALESCE_TYU_SIZE    0x010
39
40 #define MLXBF_I2C_GPIO_TYU_ADDR        0x02802000
41 #define MLXBF_I2C_GPIO_TYU_SIZE        0x100
42
43 #define MLXBF_I2C_COREPLL_TYU_ADDR     0x02800358
44 #define MLXBF_I2C_COREPLL_TYU_SIZE     0x008
45
46 #define MLXBF_I2C_COREPLL_YU_ADDR      0x02800c30
47 #define MLXBF_I2C_COREPLL_YU_SIZE      0x00c
48
49 #define MLXBF_I2C_COREPLL_RSH_YU_ADDR  0x13409824
50 #define MLXBF_I2C_COREPLL_RSH_YU_SIZE  0x00c
51
52 #define MLXBF_I2C_SHARED_RES_MAX       3
53
54 /*
55  * Note that the following SMBus, CAUSE, GPIO and PLL register addresses
56  * refer to their respective offsets relative to the corresponding
57  * memory-mapped region whose addresses are specified in either the DT or
58  * the ACPI tables or above.
59  */
60
61 /*
62  * SMBus Master core clock frequency. Timing configurations are
63  * strongly dependent on the core clock frequency of the SMBus
64  * Master. Default value is set to 400MHz.
65  */
66 #define MLXBF_I2C_TYU_PLL_OUT_FREQ  (400 * 1000 * 1000)
67 /* Reference clock for Bluefield - 156 MHz. */
68 #define MLXBF_I2C_PLL_IN_FREQ       156250000ULL
69
70 /* Constant used to determine the PLL frequency. */
71 #define MLNXBF_I2C_COREPLL_CONST    16384ULL
72
73 #define MLXBF_I2C_FREQUENCY_1GHZ  1000000000ULL
74
75 /* PLL registers. */
76 #define MLXBF_I2C_CORE_PLL_REG1         0x4
77 #define MLXBF_I2C_CORE_PLL_REG2         0x8
78
79 /* OR cause register. */
80 #define MLXBF_I2C_CAUSE_OR_EVTEN0    0x14
81 #define MLXBF_I2C_CAUSE_OR_CLEAR     0x18
82
83 /* Arbiter Cause Register. */
84 #define MLXBF_I2C_CAUSE_ARBITER      0x1c
85
86 /*
87  * Cause Status flags. Note that those bits might be considered
88  * as interrupt enabled bits.
89  */
90
91 /* Transaction ended with STOP. */
92 #define MLXBF_I2C_CAUSE_TRANSACTION_ENDED  BIT(0)
93 /* Master arbitration lost. */
94 #define MLXBF_I2C_CAUSE_M_ARBITRATION_LOST BIT(1)
95 /* Unexpected start detected. */
96 #define MLXBF_I2C_CAUSE_UNEXPECTED_START   BIT(2)
97 /* Unexpected stop detected. */
98 #define MLXBF_I2C_CAUSE_UNEXPECTED_STOP    BIT(3)
99 /* Wait for transfer continuation. */
100 #define MLXBF_I2C_CAUSE_WAIT_FOR_FW_DATA   BIT(4)
101 /* Failed to generate STOP. */
102 #define MLXBF_I2C_CAUSE_PUT_STOP_FAILED    BIT(5)
103 /* Failed to generate START. */
104 #define MLXBF_I2C_CAUSE_PUT_START_FAILED   BIT(6)
105 /* Clock toggle completed. */
106 #define MLXBF_I2C_CAUSE_CLK_TOGGLE_DONE    BIT(7)
107 /* Transfer timeout occurred. */
108 #define MLXBF_I2C_CAUSE_M_FW_TIMEOUT       BIT(8)
109 /* Master busy bit reset. */
110 #define MLXBF_I2C_CAUSE_M_GW_BUSY_FALL     BIT(9)
111
112 #define MLXBF_I2C_CAUSE_MASTER_ARBITER_BITS_MASK     GENMASK(9, 0)
113
114 #define MLXBF_I2C_CAUSE_MASTER_STATUS_ERROR \
115         (MLXBF_I2C_CAUSE_M_ARBITRATION_LOST | \
116          MLXBF_I2C_CAUSE_UNEXPECTED_START | \
117          MLXBF_I2C_CAUSE_UNEXPECTED_STOP | \
118          MLXBF_I2C_CAUSE_PUT_STOP_FAILED | \
119          MLXBF_I2C_CAUSE_PUT_START_FAILED | \
120          MLXBF_I2C_CAUSE_CLK_TOGGLE_DONE | \
121          MLXBF_I2C_CAUSE_M_FW_TIMEOUT)
122
123 /*
124  * Slave cause status flags. Note that those bits might be considered
125  * as interrupt enabled bits.
126  */
127
128 /* Write transaction received successfully. */
129 #define MLXBF_I2C_CAUSE_WRITE_SUCCESS         BIT(0)
130 /* Read transaction received, waiting for response. */
131 #define MLXBF_I2C_CAUSE_READ_WAIT_FW_RESPONSE BIT(13)
132 /* Slave busy bit reset. */
133 #define MLXBF_I2C_CAUSE_S_GW_BUSY_FALL        BIT(18)
134
135 /* Cause coalesce registers. */
136 #define MLXBF_I2C_CAUSE_COALESCE_0        0x00
137
138 #define MLXBF_I2C_CAUSE_TYU_SLAVE_BIT   3
139 #define MLXBF_I2C_CAUSE_YU_SLAVE_BIT    1
140
141 /* Functional enable register. */
142 #define MLXBF_I2C_GPIO_0_FUNC_EN_0    0x28
143 /* Force OE enable register. */
144 #define MLXBF_I2C_GPIO_0_FORCE_OE_EN  0x30
145 /*
146  * Note that Smbus GWs are on GPIOs 30:25. Two pins are used to control
147  * SDA/SCL lines:
148  *
149  *  SMBUS GW0 -> bits[26:25]
150  *  SMBUS GW1 -> bits[28:27]
151  *  SMBUS GW2 -> bits[30:29]
152  */
153 #define MLXBF_I2C_GPIO_SMBUS_GW_PINS(num) (25 + ((num) << 1))
154
155 /* Note that gw_id can be 0,1 or 2. */
156 #define MLXBF_I2C_GPIO_SMBUS_GW_MASK(num) \
157         (0xffffffff & (~(0x3 << MLXBF_I2C_GPIO_SMBUS_GW_PINS(num))))
158
159 #define MLXBF_I2C_GPIO_SMBUS_GW_RESET_PINS(num, val) \
160         ((val) & MLXBF_I2C_GPIO_SMBUS_GW_MASK(num))
161
162 #define MLXBF_I2C_GPIO_SMBUS_GW_ASSERT_PINS(num, val) \
163         ((val) | (0x3 << MLXBF_I2C_GPIO_SMBUS_GW_PINS(num)))
164
165 /*
166  * Defines SMBus operating frequency and core clock frequency.
167  * According to ADB files, default values are compliant to 100KHz SMBus
168  * @ 400MHz core clock. The driver should be able to calculate core
169  * frequency based on PLL parameters.
170  */
171 #define MLXBF_I2C_COREPLL_FREQ          MLXBF_I2C_TYU_PLL_OUT_FREQ
172
173 /* Core PLL TYU configuration. */
174 #define MLXBF_I2C_COREPLL_CORE_F_TYU_MASK   GENMASK(15, 3)
175 #define MLXBF_I2C_COREPLL_CORE_OD_TYU_MASK  GENMASK(19, 16)
176 #define MLXBF_I2C_COREPLL_CORE_R_TYU_MASK   GENMASK(25, 20)
177
178 /* Core PLL YU configuration. */
179 #define MLXBF_I2C_COREPLL_CORE_F_YU_MASK    GENMASK(25, 0)
180 #define MLXBF_I2C_COREPLL_CORE_OD_YU_MASK   GENMASK(3, 0)
181 #define MLXBF_I2C_COREPLL_CORE_R_YU_MASK    GENMASK(31, 26)
182
183 /* SMBus timing parameters. */
184 #define MLXBF_I2C_SMBUS_TIMER_SCL_LOW_SCL_HIGH    0x00
185 #define MLXBF_I2C_SMBUS_TIMER_FALL_RISE_SPIKE     0x04
186 #define MLXBF_I2C_SMBUS_TIMER_THOLD               0x08
187 #define MLXBF_I2C_SMBUS_TIMER_TSETUP_START_STOP   0x0c
188 #define MLXBF_I2C_SMBUS_TIMER_TSETUP_DATA         0x10
189 #define MLXBF_I2C_SMBUS_THIGH_MAX_TBUF            0x14
190 #define MLXBF_I2C_SMBUS_SCL_LOW_TIMEOUT           0x18
191
192 #define MLXBF_I2C_SHIFT_0   0
193 #define MLXBF_I2C_SHIFT_8   8
194 #define MLXBF_I2C_SHIFT_16  16
195 #define MLXBF_I2C_SHIFT_24  24
196
197 #define MLXBF_I2C_MASK_8    GENMASK(7, 0)
198 #define MLXBF_I2C_MASK_16   GENMASK(15, 0)
199
200 #define MLXBF_I2C_MST_ADDR_OFFSET         0x200
201
202 /* SMBus Master GW. */
203 #define MLXBF_I2C_SMBUS_MASTER_GW         0x0
204 /* Number of bytes received and sent. */
205 #define MLXBF_I2C_YU_SMBUS_RS_BYTES       0x100
206 #define MLXBF_I2C_RSH_YU_SMBUS_RS_BYTES   0x10c
207 /* Packet error check (PEC) value. */
208 #define MLXBF_I2C_SMBUS_MASTER_PEC        0x104
209 /* Status bits (ACK/NACK/FW Timeout). */
210 #define MLXBF_I2C_SMBUS_MASTER_STATUS     0x108
211 /* SMbus Master Finite State Machine. */
212 #define MLXBF_I2C_YU_SMBUS_MASTER_FSM     0x110
213 #define MLXBF_I2C_RSH_YU_SMBUS_MASTER_FSM 0x100
214
215 /* SMBus master GW control bits offset in MLXBF_I2C_SMBUS_MASTER_GW[31:3]. */
216 #define MLXBF_I2C_MASTER_LOCK_BIT         BIT(31) /* Lock bit. */
217 #define MLXBF_I2C_MASTER_BUSY_BIT         BIT(30) /* Busy bit. */
218 #define MLXBF_I2C_MASTER_START_BIT        BIT(29) /* Control start. */
219 #define MLXBF_I2C_MASTER_CTL_WRITE_BIT    BIT(28) /* Control write phase. */
220 #define MLXBF_I2C_MASTER_CTL_READ_BIT     BIT(19) /* Control read phase. */
221 #define MLXBF_I2C_MASTER_STOP_BIT         BIT(3)  /* Control stop. */
222
223 #define MLXBF_I2C_MASTER_ENABLE \
224         (MLXBF_I2C_MASTER_LOCK_BIT | MLXBF_I2C_MASTER_BUSY_BIT | \
225          MLXBF_I2C_MASTER_START_BIT | MLXBF_I2C_MASTER_STOP_BIT)
226
227 #define MLXBF_I2C_MASTER_ENABLE_WRITE \
228         (MLXBF_I2C_MASTER_ENABLE | MLXBF_I2C_MASTER_CTL_WRITE_BIT)
229
230 #define MLXBF_I2C_MASTER_ENABLE_READ \
231         (MLXBF_I2C_MASTER_ENABLE | MLXBF_I2C_MASTER_CTL_READ_BIT)
232
233 #define MLXBF_I2C_MASTER_WRITE_SHIFT      21 /* Control write bytes */
234 #define MLXBF_I2C_MASTER_SEND_PEC_SHIFT   20 /* Send PEC byte when set to 1 */
235 #define MLXBF_I2C_MASTER_PARSE_EXP_SHIFT  11 /* Control parse expected bytes */
236 #define MLXBF_I2C_MASTER_SLV_ADDR_SHIFT   12 /* Slave address */
237 #define MLXBF_I2C_MASTER_READ_SHIFT       4  /* Control read bytes */
238
239 /* SMBus master GW Data descriptor. */
240 #define MLXBF_I2C_MASTER_DATA_DESC_ADDR   0x80
241 #define MLXBF_I2C_MASTER_DATA_DESC_SIZE   0x80 /* Size in bytes. */
242
243 /* Maximum bytes to read/write per SMBus transaction. */
244 #define MLXBF_I2C_MASTER_DATA_R_LENGTH  MLXBF_I2C_MASTER_DATA_DESC_SIZE
245 #define MLXBF_I2C_MASTER_DATA_W_LENGTH (MLXBF_I2C_MASTER_DATA_DESC_SIZE - 1)
246
247 /* All bytes were transmitted. */
248 #define MLXBF_I2C_SMBUS_STATUS_BYTE_CNT_DONE      BIT(0)
249 /* NACK received. */
250 #define MLXBF_I2C_SMBUS_STATUS_NACK_RCV           BIT(1)
251 /* Slave's byte count >128 bytes. */
252 #define MLXBF_I2C_SMBUS_STATUS_READ_ERR           BIT(2)
253 /* Timeout occurred. */
254 #define MLXBF_I2C_SMBUS_STATUS_FW_TIMEOUT         BIT(3)
255
256 #define MLXBF_I2C_SMBUS_MASTER_STATUS_MASK        GENMASK(3, 0)
257
258 #define MLXBF_I2C_SMBUS_MASTER_STATUS_ERROR \
259         (MLXBF_I2C_SMBUS_STATUS_NACK_RCV | \
260          MLXBF_I2C_SMBUS_STATUS_READ_ERR | \
261          MLXBF_I2C_SMBUS_STATUS_FW_TIMEOUT)
262
263 #define MLXBF_I2C_SMBUS_MASTER_FSM_STOP_MASK      BIT(31)
264 #define MLXBF_I2C_SMBUS_MASTER_FSM_PS_STATE_MASK  BIT(15)
265
266 #define MLXBF_I2C_SLV_ADDR_OFFSET             0x400
267
268 /* SMBus slave GW. */
269 #define MLXBF_I2C_SMBUS_SLAVE_GW              0x0
270 /* Number of bytes received and sent from/to master. */
271 #define MLXBF_I2C_SMBUS_SLAVE_RS_MASTER_BYTES 0x100
272 /* Packet error check (PEC) value. */
273 #define MLXBF_I2C_SMBUS_SLAVE_PEC             0x104
274 /* SMBus slave Finite State Machine (FSM). */
275 #define MLXBF_I2C_SMBUS_SLAVE_FSM             0x110
276 /*
277  * Should be set when all raised causes handled, and cleared by HW on
278  * every new cause.
279  */
280 #define MLXBF_I2C_SMBUS_SLAVE_READY           0x12c
281
282 /* SMBus slave GW control bits offset in MLXBF_I2C_SMBUS_SLAVE_GW[31:19]. */
283 #define MLXBF_I2C_SLAVE_BUSY_BIT         BIT(30) /* Busy bit. */
284 #define MLXBF_I2C_SLAVE_WRITE_BIT        BIT(29) /* Control write enable. */
285
286 #define MLXBF_I2C_SLAVE_ENABLE \
287         (MLXBF_I2C_SLAVE_BUSY_BIT | MLXBF_I2C_SLAVE_WRITE_BIT)
288
289 #define MLXBF_I2C_SLAVE_WRITE_BYTES_SHIFT 22 /* Number of bytes to write. */
290 #define MLXBF_I2C_SLAVE_SEND_PEC_SHIFT    21 /* Send PEC byte shift. */
291
292 /* SMBus slave GW Data descriptor. */
293 #define MLXBF_I2C_SLAVE_DATA_DESC_ADDR   0x80
294 #define MLXBF_I2C_SLAVE_DATA_DESC_SIZE   0x80 /* Size in bytes. */
295
296 /* SMbus slave configuration registers. */
297 #define MLXBF_I2C_SMBUS_SLAVE_ADDR_CFG        0x114
298 #define MLXBF_I2C_SMBUS_SLAVE_ADDR_CNT        16
299 #define MLXBF_I2C_SMBUS_SLAVE_ADDR_EN_BIT     BIT(7)
300 #define MLXBF_I2C_SMBUS_SLAVE_ADDR_MASK       GENMASK(6, 0)
301
302 /*
303  * Timeout is given in microsends. Note also that timeout handling is not
304  * exact.
305  */
306 #define MLXBF_I2C_SMBUS_TIMEOUT   (300 * 1000) /* 300ms */
307 #define MLXBF_I2C_SMBUS_LOCK_POLL_TIMEOUT (300 * 1000) /* 300ms */
308
309 /* Polling frequency in microseconds. */
310 #define MLXBF_I2C_POLL_FREQ_IN_USEC        200
311
312 #define MLXBF_I2C_SMBUS_OP_CNT_1   1
313 #define MLXBF_I2C_SMBUS_OP_CNT_2   2
314 #define MLXBF_I2C_SMBUS_OP_CNT_3   3
315 #define MLXBF_I2C_SMBUS_MAX_OP_CNT MLXBF_I2C_SMBUS_OP_CNT_3
316
317 /* Helper macro to define an I2C resource parameters. */
318 #define MLXBF_I2C_RES_PARAMS(addr, size, str) \
319         { \
320                 .start = (addr), \
321                 .end = (addr) + (size) - 1, \
322                 .name = (str) \
323         }
324
325 enum {
326         MLXBF_I2C_TIMING_100KHZ = 100000,
327         MLXBF_I2C_TIMING_400KHZ = 400000,
328         MLXBF_I2C_TIMING_1000KHZ = 1000000,
329 };
330
331 enum {
332         MLXBF_I2C_F_READ = BIT(0),
333         MLXBF_I2C_F_WRITE = BIT(1),
334         MLXBF_I2C_F_NORESTART = BIT(3),
335         MLXBF_I2C_F_SMBUS_OPERATION = BIT(4),
336         MLXBF_I2C_F_SMBUS_BLOCK = BIT(5),
337         MLXBF_I2C_F_SMBUS_PEC = BIT(6),
338         MLXBF_I2C_F_SMBUS_PROCESS_CALL = BIT(7),
339 };
340
341 /* Mellanox BlueField chip type. */
342 enum mlxbf_i2c_chip_type {
343         MLXBF_I2C_CHIP_TYPE_1, /* Mellanox BlueField-1 chip. */
344         MLXBF_I2C_CHIP_TYPE_2, /* Mellanox BlueField-2 chip. */
345         MLXBF_I2C_CHIP_TYPE_3 /* Mellanox BlueField-3 chip. */
346 };
347
348 /* List of chip resources that are being accessed by the driver. */
349 enum {
350         MLXBF_I2C_SMBUS_RES,
351         MLXBF_I2C_MST_CAUSE_RES,
352         MLXBF_I2C_SLV_CAUSE_RES,
353         MLXBF_I2C_COALESCE_RES,
354         MLXBF_I2C_SMBUS_TIMER_RES,
355         MLXBF_I2C_SMBUS_MST_RES,
356         MLXBF_I2C_SMBUS_SLV_RES,
357         MLXBF_I2C_COREPLL_RES,
358         MLXBF_I2C_GPIO_RES,
359         MLXBF_I2C_END_RES
360 };
361
362 /* Encapsulates timing parameters. */
363 struct mlxbf_i2c_timings {
364         u16 scl_high;           /* Clock high period. */
365         u16 scl_low;            /* Clock low period. */
366         u8 sda_rise;            /* Data rise time. */
367         u8 sda_fall;            /* Data fall time. */
368         u8 scl_rise;            /* Clock rise time. */
369         u8 scl_fall;            /* Clock fall time. */
370         u16 hold_start;         /* Hold time after (REPEATED) START. */
371         u16 hold_data;          /* Data hold time. */
372         u16 setup_start;        /* REPEATED START condition setup time. */
373         u16 setup_stop;         /* STOP condition setup time. */
374         u16 setup_data;         /* Data setup time. */
375         u16 pad;                /* Padding. */
376         u16 buf;                /* Bus free time between STOP and START. */
377         u16 thigh_max;          /* Thigh max. */
378         u32 timeout;            /* Detect clock low timeout. */
379 };
380
381 struct mlxbf_i2c_smbus_operation {
382         u32 flags;
383         u32 length; /* Buffer length in bytes. */
384         u8 *buffer;
385 };
386
387 struct mlxbf_i2c_smbus_request {
388         u8 slave;
389         u8 operation_cnt;
390         struct mlxbf_i2c_smbus_operation operation[MLXBF_I2C_SMBUS_MAX_OP_CNT];
391 };
392
393 struct mlxbf_i2c_resource {
394         void __iomem *io;
395         struct resource *params;
396         struct mutex *lock; /* Mutex to protect mlxbf_i2c_resource. */
397         u8 type;
398 };
399
400 struct mlxbf_i2c_chip_info {
401         enum mlxbf_i2c_chip_type type;
402         /* Chip shared resources that are being used by the I2C controller. */
403         struct mlxbf_i2c_resource *shared_res[MLXBF_I2C_SHARED_RES_MAX];
404
405         /* Callback to calculate the core PLL frequency. */
406         u64 (*calculate_freq)(struct mlxbf_i2c_resource *corepll_res);
407
408         /* Registers' address offset */
409         u32 smbus_master_rs_bytes_off;
410         u32 smbus_master_fsm_off;
411 };
412
413 struct mlxbf_i2c_priv {
414         const struct mlxbf_i2c_chip_info *chip;
415         struct i2c_adapter adap;
416         struct mlxbf_i2c_resource *smbus;
417         struct mlxbf_i2c_resource *timer;
418         struct mlxbf_i2c_resource *mst;
419         struct mlxbf_i2c_resource *slv;
420         struct mlxbf_i2c_resource *mst_cause;
421         struct mlxbf_i2c_resource *slv_cause;
422         struct mlxbf_i2c_resource *coalesce;
423         u64 frequency; /* Core frequency in Hz. */
424         int bus; /* Physical bus identifier. */
425         int irq;
426         struct i2c_client *slave[MLXBF_I2C_SMBUS_SLAVE_ADDR_CNT];
427         u32 resource_version;
428 };
429
430 /* Core PLL frequency. */
431 static u64 mlxbf_i2c_corepll_frequency;
432
433 static struct resource mlxbf_i2c_coalesce_tyu_params =
434                 MLXBF_I2C_RES_PARAMS(MLXBF_I2C_COALESCE_TYU_ADDR,
435                                      MLXBF_I2C_COALESCE_TYU_SIZE,
436                                      "COALESCE_MEM");
437 static struct resource mlxbf_i2c_corepll_tyu_params =
438                 MLXBF_I2C_RES_PARAMS(MLXBF_I2C_COREPLL_TYU_ADDR,
439                                      MLXBF_I2C_COREPLL_TYU_SIZE,
440                                      "COREPLL_MEM");
441 static struct resource mlxbf_i2c_corepll_yu_params =
442                 MLXBF_I2C_RES_PARAMS(MLXBF_I2C_COREPLL_YU_ADDR,
443                                      MLXBF_I2C_COREPLL_YU_SIZE,
444                                      "COREPLL_MEM");
445 static struct resource mlxbf_i2c_corepll_rsh_yu_params =
446                 MLXBF_I2C_RES_PARAMS(MLXBF_I2C_COREPLL_RSH_YU_ADDR,
447                                      MLXBF_I2C_COREPLL_RSH_YU_SIZE,
448                                      "COREPLL_MEM");
449 static struct resource mlxbf_i2c_gpio_tyu_params =
450                 MLXBF_I2C_RES_PARAMS(MLXBF_I2C_GPIO_TYU_ADDR,
451                                      MLXBF_I2C_GPIO_TYU_SIZE,
452                                      "GPIO_MEM");
453
454 static struct mutex mlxbf_i2c_coalesce_lock;
455 static struct mutex mlxbf_i2c_corepll_lock;
456 static struct mutex mlxbf_i2c_gpio_lock;
457
458 static struct mlxbf_i2c_resource mlxbf_i2c_coalesce_res[] = {
459         [MLXBF_I2C_CHIP_TYPE_1] = {
460                 .params = &mlxbf_i2c_coalesce_tyu_params,
461                 .lock = &mlxbf_i2c_coalesce_lock,
462                 .type = MLXBF_I2C_COALESCE_RES
463         },
464         {}
465 };
466
467 static struct mlxbf_i2c_resource mlxbf_i2c_corepll_res[] = {
468         [MLXBF_I2C_CHIP_TYPE_1] = {
469                 .params = &mlxbf_i2c_corepll_tyu_params,
470                 .lock = &mlxbf_i2c_corepll_lock,
471                 .type = MLXBF_I2C_COREPLL_RES
472         },
473         [MLXBF_I2C_CHIP_TYPE_2] = {
474                 .params = &mlxbf_i2c_corepll_yu_params,
475                 .lock = &mlxbf_i2c_corepll_lock,
476                 .type = MLXBF_I2C_COREPLL_RES,
477         },
478         [MLXBF_I2C_CHIP_TYPE_3] = {
479                 .params = &mlxbf_i2c_corepll_rsh_yu_params,
480                 .lock = &mlxbf_i2c_corepll_lock,
481                 .type = MLXBF_I2C_COREPLL_RES,
482         }
483 };
484
485 static struct mlxbf_i2c_resource mlxbf_i2c_gpio_res[] = {
486         [MLXBF_I2C_CHIP_TYPE_1] = {
487                 .params = &mlxbf_i2c_gpio_tyu_params,
488                 .lock = &mlxbf_i2c_gpio_lock,
489                 .type = MLXBF_I2C_GPIO_RES
490         },
491         {}
492 };
493
494 static u8 mlxbf_i2c_bus_count;
495
496 static struct mutex mlxbf_i2c_bus_lock;
497
498 /*
499  * Function to poll a set of bits at a specific address; it checks whether
500  * the bits are equal to zero when eq_zero is set to 'true', and not equal
501  * to zero when eq_zero is set to 'false'.
502  * Note that the timeout is given in microseconds.
503  */
504 static u32 mlxbf_i2c_poll(void __iomem *io, u32 addr, u32 mask,
505                             bool eq_zero, u32  timeout)
506 {
507         u32 bits;
508
509         timeout = (timeout / MLXBF_I2C_POLL_FREQ_IN_USEC) + 1;
510
511         do {
512                 bits = readl(io + addr) & mask;
513                 if (eq_zero ? bits == 0 : bits != 0)
514                         return eq_zero ? 1 : bits;
515                 udelay(MLXBF_I2C_POLL_FREQ_IN_USEC);
516         } while (timeout-- != 0);
517
518         return 0;
519 }
520
521 /*
522  * SW must make sure that the SMBus Master GW is idle before starting
523  * a transaction. Accordingly, this function polls the Master FSM stop
524  * bit; it returns false when the bit is asserted, true if not.
525  */
526 static bool mlxbf_i2c_smbus_master_wait_for_idle(struct mlxbf_i2c_priv *priv)
527 {
528         u32 mask = MLXBF_I2C_SMBUS_MASTER_FSM_STOP_MASK;
529         u32 addr = priv->chip->smbus_master_fsm_off;
530         u32 timeout = MLXBF_I2C_SMBUS_TIMEOUT;
531
532         if (mlxbf_i2c_poll(priv->mst->io, addr, mask, true, timeout))
533                 return true;
534
535         return false;
536 }
537
538 /*
539  * wait for the lock to be released before acquiring it.
540  */
541 static bool mlxbf_i2c_smbus_master_lock(struct mlxbf_i2c_priv *priv)
542 {
543         if (mlxbf_i2c_poll(priv->mst->io, MLXBF_I2C_SMBUS_MASTER_GW,
544                            MLXBF_I2C_MASTER_LOCK_BIT, true,
545                            MLXBF_I2C_SMBUS_LOCK_POLL_TIMEOUT))
546                 return true;
547
548         return false;
549 }
550
551 static void mlxbf_i2c_smbus_master_unlock(struct mlxbf_i2c_priv *priv)
552 {
553         /* Clear the gw to clear the lock */
554         writel(0, priv->mst->io + MLXBF_I2C_SMBUS_MASTER_GW);
555 }
556
557 static bool mlxbf_i2c_smbus_transaction_success(u32 master_status,
558                                                 u32 cause_status)
559 {
560         /*
561          * When transaction ended with STOP, all bytes were transmitted,
562          * and no NACK received, then the transaction ended successfully.
563          * On the other hand, when the GW is configured with the stop bit
564          * de-asserted then the SMBus expects the following GW configuration
565          * for transfer continuation.
566          */
567         if ((cause_status & MLXBF_I2C_CAUSE_WAIT_FOR_FW_DATA) ||
568             ((cause_status & MLXBF_I2C_CAUSE_TRANSACTION_ENDED) &&
569              (master_status & MLXBF_I2C_SMBUS_STATUS_BYTE_CNT_DONE) &&
570              !(master_status & MLXBF_I2C_SMBUS_STATUS_NACK_RCV)))
571                 return true;
572
573         return false;
574 }
575
576 /*
577  * Poll SMBus master status and return transaction status,
578  * i.e. whether succeeded or failed. I2C and SMBus fault codes
579  * are returned as negative numbers from most calls, with zero
580  * or some positive number indicating a non-fault return.
581  */
582 static int mlxbf_i2c_smbus_check_status(struct mlxbf_i2c_priv *priv)
583 {
584         u32 master_status_bits;
585         u32 cause_status_bits;
586
587         /*
588          * GW busy bit is raised by the driver and cleared by the HW
589          * when the transaction is completed. The busy bit is a good
590          * indicator of transaction status. So poll the busy bit, and
591          * then read the cause and master status bits to determine if
592          * errors occurred during the transaction.
593          */
594         mlxbf_i2c_poll(priv->mst->io, MLXBF_I2C_SMBUS_MASTER_GW,
595                          MLXBF_I2C_MASTER_BUSY_BIT, true,
596                          MLXBF_I2C_SMBUS_TIMEOUT);
597
598         /* Read cause status bits. */
599         cause_status_bits = readl(priv->mst_cause->io +
600                                         MLXBF_I2C_CAUSE_ARBITER);
601         cause_status_bits &= MLXBF_I2C_CAUSE_MASTER_ARBITER_BITS_MASK;
602
603         /*
604          * Parse both Cause and Master GW bits, then return transaction status.
605          */
606
607         master_status_bits = readl(priv->mst->io +
608                                         MLXBF_I2C_SMBUS_MASTER_STATUS);
609         master_status_bits &= MLXBF_I2C_SMBUS_MASTER_STATUS_MASK;
610
611         if (mlxbf_i2c_smbus_transaction_success(master_status_bits,
612                                                 cause_status_bits))
613                 return 0;
614
615         /*
616          * In case of timeout on GW busy, the ISR will clear busy bit but
617          * transaction ended bits cause will not be set so the transaction
618          * fails. Then, we must check Master GW status bits.
619          */
620         if ((master_status_bits & MLXBF_I2C_SMBUS_MASTER_STATUS_ERROR) &&
621             (cause_status_bits & (MLXBF_I2C_CAUSE_TRANSACTION_ENDED |
622                                   MLXBF_I2C_CAUSE_M_GW_BUSY_FALL)))
623                 return -EIO;
624
625         if (cause_status_bits & MLXBF_I2C_CAUSE_MASTER_STATUS_ERROR)
626                 return -EAGAIN;
627
628         return -ETIMEDOUT;
629 }
630
631 static void mlxbf_i2c_smbus_write_data(struct mlxbf_i2c_priv *priv,
632                                        const u8 *data, u8 length, u32 addr,
633                                        bool is_master)
634 {
635         u8 offset, aligned_length;
636         u32 data32;
637
638         aligned_length = round_up(length, 4);
639
640         /*
641          * Copy data bytes from 4-byte aligned source buffer.
642          * Data copied to the Master GW Data Descriptor MUST be shifted
643          * left so the data starts at the MSB of the descriptor registers
644          * as required by the underlying hardware. Enable byte swapping
645          * when writing data bytes to the 32 * 32-bit HW Data registers
646          * a.k.a Master GW Data Descriptor.
647          */
648         for (offset = 0; offset < aligned_length; offset += sizeof(u32)) {
649                 data32 = *((u32 *)(data + offset));
650                 if (is_master)
651                         iowrite32be(data32, priv->mst->io + addr + offset);
652                 else
653                         iowrite32be(data32, priv->slv->io + addr + offset);
654         }
655 }
656
657 static void mlxbf_i2c_smbus_read_data(struct mlxbf_i2c_priv *priv,
658                                       u8 *data, u8 length, u32 addr,
659                                       bool is_master)
660 {
661         u32 data32, mask;
662         u8 byte, offset;
663
664         mask = sizeof(u32) - 1;
665
666         /*
667          * Data bytes in the Master GW Data Descriptor are shifted left
668          * so the data starts at the MSB of the descriptor registers as
669          * set by the underlying hardware. Enable byte swapping while
670          * reading data bytes from the 32 * 32-bit HW Data registers
671          * a.k.a Master GW Data Descriptor.
672          */
673
674         for (offset = 0; offset < (length & ~mask); offset += sizeof(u32)) {
675                 if (is_master)
676                         data32 = ioread32be(priv->mst->io + addr + offset);
677                 else
678                         data32 = ioread32be(priv->slv->io + addr + offset);
679                 *((u32 *)(data + offset)) = data32;
680         }
681
682         if (!(length & mask))
683                 return;
684
685         if (is_master)
686                 data32 = ioread32be(priv->mst->io + addr + offset);
687         else
688                 data32 = ioread32be(priv->slv->io + addr + offset);
689
690         for (byte = 0; byte < (length & mask); byte++) {
691                 data[offset + byte] = data32 & GENMASK(7, 0);
692                 data32 = ror32(data32, MLXBF_I2C_SHIFT_8);
693         }
694 }
695
696 static int mlxbf_i2c_smbus_enable(struct mlxbf_i2c_priv *priv, u8 slave,
697                                   u8 len, u8 block_en, u8 pec_en, bool read)
698 {
699         u32 command;
700
701         /* Set Master GW control word. */
702         if (read) {
703                 command = MLXBF_I2C_MASTER_ENABLE_READ;
704                 command |= rol32(len, MLXBF_I2C_MASTER_READ_SHIFT);
705         } else {
706                 command = MLXBF_I2C_MASTER_ENABLE_WRITE;
707                 command |= rol32(len, MLXBF_I2C_MASTER_WRITE_SHIFT);
708         }
709         command |= rol32(slave, MLXBF_I2C_MASTER_SLV_ADDR_SHIFT);
710         command |= rol32(block_en, MLXBF_I2C_MASTER_PARSE_EXP_SHIFT);
711         command |= rol32(pec_en, MLXBF_I2C_MASTER_SEND_PEC_SHIFT);
712
713         /* Clear status bits. */
714         writel(0x0, priv->mst->io + MLXBF_I2C_SMBUS_MASTER_STATUS);
715         /* Set the cause data. */
716         writel(~0x0, priv->mst_cause->io + MLXBF_I2C_CAUSE_OR_CLEAR);
717         /* Zero PEC byte. */
718         writel(0x0, priv->mst->io + MLXBF_I2C_SMBUS_MASTER_PEC);
719         /* Zero byte count. */
720         writel(0x0, priv->mst->io + priv->chip->smbus_master_rs_bytes_off);
721
722         /* GW activation. */
723         writel(command, priv->mst->io + MLXBF_I2C_SMBUS_MASTER_GW);
724
725         /*
726          * Poll master status and check status bits. An ACK is sent when
727          * completing writing data to the bus (Master 'byte_count_done' bit
728          * is set to 1).
729          */
730         return mlxbf_i2c_smbus_check_status(priv);
731 }
732
733 static int
734 mlxbf_i2c_smbus_start_transaction(struct mlxbf_i2c_priv *priv,
735                                   struct mlxbf_i2c_smbus_request *request)
736 {
737         u8 data_desc[MLXBF_I2C_MASTER_DATA_DESC_SIZE] = { 0 };
738         u8 op_idx, data_idx, data_len, write_len, read_len;
739         struct mlxbf_i2c_smbus_operation *operation;
740         u8 read_en, write_en, block_en, pec_en;
741         u8 slave, flags, addr;
742         u8 *read_buf;
743         int ret = 0;
744
745         if (request->operation_cnt > MLXBF_I2C_SMBUS_MAX_OP_CNT)
746                 return -EINVAL;
747
748         read_buf = NULL;
749         data_idx = 0;
750         read_en = 0;
751         write_en = 0;
752         write_len = 0;
753         read_len = 0;
754         block_en = 0;
755         pec_en = 0;
756         slave = request->slave & GENMASK(6, 0);
757         addr = slave << 1;
758
759         /*
760          * Try to acquire the smbus gw lock before any reads of the GW register since
761          * a read sets the lock.
762          */
763         if (WARN_ON(!mlxbf_i2c_smbus_master_lock(priv)))
764                 return -EBUSY;
765
766         /* Check whether the HW is idle */
767         if (WARN_ON(!mlxbf_i2c_smbus_master_wait_for_idle(priv))) {
768                 ret = -EBUSY;
769                 goto out_unlock;
770         }
771
772         /* Set first byte. */
773         data_desc[data_idx++] = addr;
774
775         for (op_idx = 0; op_idx < request->operation_cnt; op_idx++) {
776                 operation = &request->operation[op_idx];
777                 flags = operation->flags;
778
779                 /*
780                  * Note that read and write operations might be handled by a
781                  * single command. If the MLXBF_I2C_F_SMBUS_OPERATION is set
782                  * then write command byte and set the optional SMBus specific
783                  * bits such as block_en and pec_en. These bits MUST be
784                  * submitted by the first operation only.
785                  */
786                 if (op_idx == 0 && flags & MLXBF_I2C_F_SMBUS_OPERATION) {
787                         block_en = flags & MLXBF_I2C_F_SMBUS_BLOCK;
788                         pec_en = flags & MLXBF_I2C_F_SMBUS_PEC;
789                 }
790
791                 if (flags & MLXBF_I2C_F_WRITE) {
792                         write_en = 1;
793                         write_len += operation->length;
794                         if (data_idx + operation->length >
795                                         MLXBF_I2C_MASTER_DATA_DESC_SIZE) {
796                                 ret = -ENOBUFS;
797                                 goto out_unlock;
798                         }
799                         memcpy(data_desc + data_idx,
800                                operation->buffer, operation->length);
801                         data_idx += operation->length;
802                 }
803                 /*
804                  * We assume that read operations are performed only once per
805                  * SMBus transaction. *TBD* protect this statement so it won't
806                  * be executed twice? or return an error if we try to read more
807                  * than once?
808                  */
809                 if (flags & MLXBF_I2C_F_READ) {
810                         read_en = 1;
811                         /* Subtract 1 as required by HW. */
812                         read_len = operation->length - 1;
813                         read_buf = operation->buffer;
814                 }
815         }
816
817         /* Set Master GW data descriptor. */
818         data_len = write_len + 1; /* Add one byte of the slave address. */
819         /*
820          * Note that data_len cannot be 0. Indeed, the slave address byte
821          * must be written to the data registers.
822          */
823         mlxbf_i2c_smbus_write_data(priv, (const u8 *)data_desc, data_len,
824                                    MLXBF_I2C_MASTER_DATA_DESC_ADDR, true);
825
826         if (write_en) {
827                 ret = mlxbf_i2c_smbus_enable(priv, slave, write_len, block_en,
828                                          pec_en, 0);
829                 if (ret)
830                         goto out_unlock;
831         }
832
833         if (read_en) {
834                 /* Write slave address to Master GW data descriptor. */
835                 mlxbf_i2c_smbus_write_data(priv, (const u8 *)&addr, 1,
836                                            MLXBF_I2C_MASTER_DATA_DESC_ADDR, true);
837                 ret = mlxbf_i2c_smbus_enable(priv, slave, read_len, block_en,
838                                          pec_en, 1);
839                 if (!ret) {
840                         /* Get Master GW data descriptor. */
841                         mlxbf_i2c_smbus_read_data(priv, data_desc, read_len + 1,
842                                              MLXBF_I2C_MASTER_DATA_DESC_ADDR, true);
843
844                         /* Get data from Master GW data descriptor. */
845                         memcpy(read_buf, data_desc, read_len + 1);
846                 }
847
848                 /*
849                  * After a read operation the SMBus FSM ps (present state)
850                  * needs to be 'manually' reset. This should be removed in
851                  * next tag integration.
852                  */
853                 writel(MLXBF_I2C_SMBUS_MASTER_FSM_PS_STATE_MASK,
854                         priv->mst->io + priv->chip->smbus_master_fsm_off);
855         }
856
857 out_unlock:
858         mlxbf_i2c_smbus_master_unlock(priv);
859
860         return ret;
861 }
862
863 /* I2C SMBus protocols. */
864
865 static void
866 mlxbf_i2c_smbus_quick_command(struct mlxbf_i2c_smbus_request *request,
867                               u8 read)
868 {
869         request->operation_cnt = MLXBF_I2C_SMBUS_OP_CNT_1;
870
871         request->operation[0].length = 0;
872         request->operation[0].flags = MLXBF_I2C_F_WRITE;
873         request->operation[0].flags |= read ? MLXBF_I2C_F_READ : 0;
874 }
875
876 static void mlxbf_i2c_smbus_byte_func(struct mlxbf_i2c_smbus_request *request,
877                                       u8 *data, bool read, bool pec_check)
878 {
879         request->operation_cnt = MLXBF_I2C_SMBUS_OP_CNT_1;
880
881         request->operation[0].length = 1;
882         request->operation[0].length += pec_check;
883
884         request->operation[0].flags = MLXBF_I2C_F_SMBUS_OPERATION;
885         request->operation[0].flags |= read ?
886                                 MLXBF_I2C_F_READ : MLXBF_I2C_F_WRITE;
887         request->operation[0].flags |= pec_check ? MLXBF_I2C_F_SMBUS_PEC : 0;
888
889         request->operation[0].buffer = data;
890 }
891
892 static void
893 mlxbf_i2c_smbus_data_byte_func(struct mlxbf_i2c_smbus_request *request,
894                                u8 *command, u8 *data, bool read, bool pec_check)
895 {
896         request->operation_cnt = MLXBF_I2C_SMBUS_OP_CNT_2;
897
898         request->operation[0].length = 1;
899         request->operation[0].flags =
900                         MLXBF_I2C_F_SMBUS_OPERATION | MLXBF_I2C_F_WRITE;
901         request->operation[0].flags |= pec_check ? MLXBF_I2C_F_SMBUS_PEC : 0;
902         request->operation[0].buffer = command;
903
904         request->operation[1].length = 1;
905         request->operation[1].length += pec_check;
906         request->operation[1].flags = read ?
907                                 MLXBF_I2C_F_READ : MLXBF_I2C_F_WRITE;
908         request->operation[1].buffer = data;
909 }
910
911 static void
912 mlxbf_i2c_smbus_data_word_func(struct mlxbf_i2c_smbus_request *request,
913                                u8 *command, u8 *data, bool read, bool pec_check)
914 {
915         request->operation_cnt = MLXBF_I2C_SMBUS_OP_CNT_2;
916
917         request->operation[0].length = 1;
918         request->operation[0].flags =
919                         MLXBF_I2C_F_SMBUS_OPERATION | MLXBF_I2C_F_WRITE;
920         request->operation[0].flags |= pec_check ? MLXBF_I2C_F_SMBUS_PEC : 0;
921         request->operation[0].buffer = command;
922
923         request->operation[1].length = 2;
924         request->operation[1].length += pec_check;
925         request->operation[1].flags = read ?
926                                 MLXBF_I2C_F_READ : MLXBF_I2C_F_WRITE;
927         request->operation[1].buffer = data;
928 }
929
930 static void
931 mlxbf_i2c_smbus_i2c_block_func(struct mlxbf_i2c_smbus_request *request,
932                                u8 *command, u8 *data, u8 *data_len, bool read,
933                                bool pec_check)
934 {
935         request->operation_cnt = MLXBF_I2C_SMBUS_OP_CNT_2;
936
937         request->operation[0].length = 1;
938         request->operation[0].flags =
939                         MLXBF_I2C_F_SMBUS_OPERATION | MLXBF_I2C_F_WRITE;
940         request->operation[0].flags |= pec_check ? MLXBF_I2C_F_SMBUS_PEC : 0;
941         request->operation[0].buffer = command;
942
943         /*
944          * As specified in the standard, the max number of bytes to read/write
945          * per block operation is 32 bytes. In Golan code, the controller can
946          * read up to 128 bytes and write up to 127 bytes.
947          */
948         request->operation[1].length =
949             (*data_len + pec_check > I2C_SMBUS_BLOCK_MAX) ?
950             I2C_SMBUS_BLOCK_MAX : *data_len + pec_check;
951         request->operation[1].flags = read ?
952                                 MLXBF_I2C_F_READ : MLXBF_I2C_F_WRITE;
953         /*
954          * Skip the first data byte, which corresponds to the number of bytes
955          * to read/write.
956          */
957         request->operation[1].buffer = data + 1;
958
959         *data_len = request->operation[1].length;
960
961         /* Set the number of byte to read. This will be used by userspace. */
962         if (read)
963                 data[0] = *data_len;
964 }
965
966 static void mlxbf_i2c_smbus_block_func(struct mlxbf_i2c_smbus_request *request,
967                                        u8 *command, u8 *data, u8 *data_len,
968                                        bool read, bool pec_check)
969 {
970         request->operation_cnt = MLXBF_I2C_SMBUS_OP_CNT_2;
971
972         request->operation[0].length = 1;
973         request->operation[0].flags =
974                         MLXBF_I2C_F_SMBUS_OPERATION | MLXBF_I2C_F_WRITE;
975         request->operation[0].flags |= MLXBF_I2C_F_SMBUS_BLOCK;
976         request->operation[0].flags |= pec_check ? MLXBF_I2C_F_SMBUS_PEC : 0;
977         request->operation[0].buffer = command;
978
979         request->operation[1].length =
980             (*data_len + pec_check > I2C_SMBUS_BLOCK_MAX) ?
981             I2C_SMBUS_BLOCK_MAX : *data_len + pec_check;
982         request->operation[1].flags = read ?
983                                 MLXBF_I2C_F_READ : MLXBF_I2C_F_WRITE;
984         request->operation[1].buffer = data + 1;
985
986         *data_len = request->operation[1].length;
987
988         /* Set the number of bytes to read. This will be used by userspace. */
989         if (read)
990                 data[0] = *data_len;
991 }
992
993 static void
994 mlxbf_i2c_smbus_process_call_func(struct mlxbf_i2c_smbus_request *request,
995                                   u8 *command, u8 *data, bool pec_check)
996 {
997         request->operation_cnt = MLXBF_I2C_SMBUS_OP_CNT_3;
998
999         request->operation[0].length = 1;
1000         request->operation[0].flags =
1001                         MLXBF_I2C_F_SMBUS_OPERATION | MLXBF_I2C_F_WRITE;
1002         request->operation[0].flags |= MLXBF_I2C_F_SMBUS_BLOCK;
1003         request->operation[0].flags |= pec_check ? MLXBF_I2C_F_SMBUS_PEC : 0;
1004         request->operation[0].buffer = command;
1005
1006         request->operation[1].length = 2;
1007         request->operation[1].flags = MLXBF_I2C_F_WRITE;
1008         request->operation[1].buffer = data;
1009
1010         request->operation[2].length = 3;
1011         request->operation[2].flags = MLXBF_I2C_F_READ;
1012         request->operation[2].buffer = data;
1013 }
1014
1015 static void
1016 mlxbf_i2c_smbus_blk_process_call_func(struct mlxbf_i2c_smbus_request *request,
1017                                       u8 *command, u8 *data, u8 *data_len,
1018                                       bool pec_check)
1019 {
1020         u32 length;
1021
1022         request->operation_cnt = MLXBF_I2C_SMBUS_OP_CNT_3;
1023
1024         request->operation[0].length = 1;
1025         request->operation[0].flags =
1026                         MLXBF_I2C_F_SMBUS_OPERATION | MLXBF_I2C_F_WRITE;
1027         request->operation[0].flags |= MLXBF_I2C_F_SMBUS_BLOCK;
1028         request->operation[0].flags |= (pec_check) ? MLXBF_I2C_F_SMBUS_PEC : 0;
1029         request->operation[0].buffer = command;
1030
1031         length = (*data_len + pec_check > I2C_SMBUS_BLOCK_MAX) ?
1032             I2C_SMBUS_BLOCK_MAX : *data_len + pec_check;
1033
1034         request->operation[1].length = length - pec_check;
1035         request->operation[1].flags = MLXBF_I2C_F_WRITE;
1036         request->operation[1].buffer = data;
1037
1038         request->operation[2].length = length;
1039         request->operation[2].flags = MLXBF_I2C_F_READ;
1040         request->operation[2].buffer = data;
1041
1042         *data_len = length; /* including PEC byte. */
1043 }
1044
1045 /* Initialization functions. */
1046
1047 static bool mlxbf_i2c_has_chip_type(struct mlxbf_i2c_priv *priv, u8 type)
1048 {
1049         return priv->chip->type == type;
1050 }
1051
1052 static struct mlxbf_i2c_resource *
1053 mlxbf_i2c_get_shared_resource(struct mlxbf_i2c_priv *priv, u8 type)
1054 {
1055         const struct mlxbf_i2c_chip_info *chip = priv->chip;
1056         struct mlxbf_i2c_resource *res;
1057         u8 res_idx = 0;
1058
1059         for (res_idx = 0; res_idx < MLXBF_I2C_SHARED_RES_MAX; res_idx++) {
1060                 res = chip->shared_res[res_idx];
1061                 if (res && res->type == type)
1062                         return res;
1063         }
1064
1065         return NULL;
1066 }
1067
1068 static int mlxbf_i2c_init_resource(struct platform_device *pdev,
1069                                    struct mlxbf_i2c_resource **res,
1070                                    u8 type)
1071 {
1072         struct mlxbf_i2c_resource *tmp_res;
1073         struct device *dev = &pdev->dev;
1074
1075         if (!res || *res || type >= MLXBF_I2C_END_RES)
1076                 return -EINVAL;
1077
1078         tmp_res = devm_kzalloc(dev, sizeof(struct mlxbf_i2c_resource),
1079                                GFP_KERNEL);
1080         if (!tmp_res)
1081                 return -ENOMEM;
1082
1083         tmp_res->io = devm_platform_get_and_ioremap_resource(pdev, type, &tmp_res->params);
1084         if (IS_ERR(tmp_res->io)) {
1085                 devm_kfree(dev, tmp_res);
1086                 return PTR_ERR(tmp_res->io);
1087         }
1088
1089         tmp_res->type = type;
1090
1091         *res = tmp_res;
1092
1093         return 0;
1094 }
1095
1096 static u32 mlxbf_i2c_get_ticks(struct mlxbf_i2c_priv *priv, u64 nanoseconds,
1097                                bool minimum)
1098 {
1099         u64 frequency;
1100         u32 ticks;
1101
1102         /*
1103          * Compute ticks as follow:
1104          *
1105          *           Ticks
1106          * Time = --------- x 10^9    =>    Ticks = Time x Frequency x 10^-9
1107          *         Frequency
1108          */
1109         frequency = priv->frequency;
1110         ticks = (nanoseconds * frequency) / MLXBF_I2C_FREQUENCY_1GHZ;
1111         /*
1112          * The number of ticks is rounded down and if minimum is equal to 1
1113          * then add one tick.
1114          */
1115         if (minimum)
1116                 ticks++;
1117
1118         return ticks;
1119 }
1120
1121 static u32 mlxbf_i2c_set_timer(struct mlxbf_i2c_priv *priv, u64 nsec, bool opt,
1122                                u32 mask, u8 shift)
1123 {
1124         u32 val = (mlxbf_i2c_get_ticks(priv, nsec, opt) & mask) << shift;
1125
1126         return val;
1127 }
1128
1129 static void mlxbf_i2c_set_timings(struct mlxbf_i2c_priv *priv,
1130                                   const struct mlxbf_i2c_timings *timings)
1131 {
1132         u32 timer;
1133
1134         timer = mlxbf_i2c_set_timer(priv, timings->scl_high,
1135                                     false, MLXBF_I2C_MASK_16,
1136                                     MLXBF_I2C_SHIFT_0);
1137         timer |= mlxbf_i2c_set_timer(priv, timings->scl_low,
1138                                      false, MLXBF_I2C_MASK_16,
1139                                      MLXBF_I2C_SHIFT_16);
1140         writel(timer, priv->timer->io +
1141                 MLXBF_I2C_SMBUS_TIMER_SCL_LOW_SCL_HIGH);
1142
1143         timer = mlxbf_i2c_set_timer(priv, timings->sda_rise, false,
1144                                     MLXBF_I2C_MASK_8, MLXBF_I2C_SHIFT_0);
1145         timer |= mlxbf_i2c_set_timer(priv, timings->sda_fall, false,
1146                                      MLXBF_I2C_MASK_8, MLXBF_I2C_SHIFT_8);
1147         timer |= mlxbf_i2c_set_timer(priv, timings->scl_rise, false,
1148                                      MLXBF_I2C_MASK_8, MLXBF_I2C_SHIFT_16);
1149         timer |= mlxbf_i2c_set_timer(priv, timings->scl_fall, false,
1150                                      MLXBF_I2C_MASK_8, MLXBF_I2C_SHIFT_24);
1151         writel(timer, priv->timer->io +
1152                 MLXBF_I2C_SMBUS_TIMER_FALL_RISE_SPIKE);
1153
1154         timer = mlxbf_i2c_set_timer(priv, timings->hold_start, true,
1155                                     MLXBF_I2C_MASK_16, MLXBF_I2C_SHIFT_0);
1156         timer |= mlxbf_i2c_set_timer(priv, timings->hold_data, true,
1157                                      MLXBF_I2C_MASK_16, MLXBF_I2C_SHIFT_16);
1158         writel(timer, priv->timer->io + MLXBF_I2C_SMBUS_TIMER_THOLD);
1159
1160         timer = mlxbf_i2c_set_timer(priv, timings->setup_start, true,
1161                                     MLXBF_I2C_MASK_16, MLXBF_I2C_SHIFT_0);
1162         timer |= mlxbf_i2c_set_timer(priv, timings->setup_stop, true,
1163                                      MLXBF_I2C_MASK_16, MLXBF_I2C_SHIFT_16);
1164         writel(timer, priv->timer->io +
1165                 MLXBF_I2C_SMBUS_TIMER_TSETUP_START_STOP);
1166
1167         timer = mlxbf_i2c_set_timer(priv, timings->setup_data, true,
1168                                     MLXBF_I2C_MASK_16, MLXBF_I2C_SHIFT_0);
1169         writel(timer, priv->timer->io + MLXBF_I2C_SMBUS_TIMER_TSETUP_DATA);
1170
1171         timer = mlxbf_i2c_set_timer(priv, timings->buf, false,
1172                                     MLXBF_I2C_MASK_16, MLXBF_I2C_SHIFT_0);
1173         timer |= mlxbf_i2c_set_timer(priv, timings->thigh_max, false,
1174                                      MLXBF_I2C_MASK_16, MLXBF_I2C_SHIFT_16);
1175         writel(timer, priv->timer->io + MLXBF_I2C_SMBUS_THIGH_MAX_TBUF);
1176
1177         timer = timings->timeout;
1178         writel(timer, priv->timer->io + MLXBF_I2C_SMBUS_SCL_LOW_TIMEOUT);
1179 }
1180
1181 enum mlxbf_i2c_timings_config {
1182         MLXBF_I2C_TIMING_CONFIG_100KHZ,
1183         MLXBF_I2C_TIMING_CONFIG_400KHZ,
1184         MLXBF_I2C_TIMING_CONFIG_1000KHZ,
1185 };
1186
1187 /*
1188  * Note that the mlxbf_i2c_timings->timeout value is not related to the
1189  * bus frequency, it is impacted by the time it takes the driver to
1190  * complete data transmission before transaction abort.
1191  */
1192 static const struct mlxbf_i2c_timings mlxbf_i2c_timings[] = {
1193         [MLXBF_I2C_TIMING_CONFIG_100KHZ] = {
1194                 .scl_high = 4810,
1195                 .scl_low = 5000,
1196                 .hold_start = 4000,
1197                 .setup_start = 4800,
1198                 .setup_stop = 4000,
1199                 .setup_data = 250,
1200                 .sda_rise = 50,
1201                 .sda_fall = 50,
1202                 .scl_rise = 50,
1203                 .scl_fall = 50,
1204                 .hold_data = 300,
1205                 .buf = 20000,
1206                 .thigh_max = 5000,
1207                 .timeout = 106500
1208         },
1209         [MLXBF_I2C_TIMING_CONFIG_400KHZ] = {
1210                 .scl_high = 1011,
1211                 .scl_low = 1300,
1212                 .hold_start = 600,
1213                 .setup_start = 700,
1214                 .setup_stop = 600,
1215                 .setup_data = 100,
1216                 .sda_rise = 50,
1217                 .sda_fall = 50,
1218                 .scl_rise = 50,
1219                 .scl_fall = 50,
1220                 .hold_data = 300,
1221                 .buf = 20000,
1222                 .thigh_max = 5000,
1223                 .timeout = 106500
1224         },
1225         [MLXBF_I2C_TIMING_CONFIG_1000KHZ] = {
1226                 .scl_high = 600,
1227                 .scl_low = 1300,
1228                 .hold_start = 600,
1229                 .setup_start = 600,
1230                 .setup_stop = 600,
1231                 .setup_data = 100,
1232                 .sda_rise = 50,
1233                 .sda_fall = 50,
1234                 .scl_rise = 50,
1235                 .scl_fall = 50,
1236                 .hold_data = 300,
1237                 .buf = 20000,
1238                 .thigh_max = 5000,
1239                 .timeout = 106500
1240         }
1241 };
1242
1243 static int mlxbf_i2c_init_timings(struct platform_device *pdev,
1244                                   struct mlxbf_i2c_priv *priv)
1245 {
1246         enum mlxbf_i2c_timings_config config_idx;
1247         struct device *dev = &pdev->dev;
1248         u32 config_khz;
1249
1250         int ret;
1251
1252         ret = device_property_read_u32(dev, "clock-frequency", &config_khz);
1253         if (ret < 0)
1254                 config_khz = I2C_MAX_STANDARD_MODE_FREQ;
1255
1256         switch (config_khz) {
1257         default:
1258                 /* Default settings is 100 KHz. */
1259                 pr_warn("Illegal value %d: defaulting to 100 KHz\n",
1260                         config_khz);
1261                 fallthrough;
1262         case I2C_MAX_STANDARD_MODE_FREQ:
1263                 config_idx = MLXBF_I2C_TIMING_CONFIG_100KHZ;
1264                 break;
1265
1266         case I2C_MAX_FAST_MODE_FREQ:
1267                 config_idx = MLXBF_I2C_TIMING_CONFIG_400KHZ;
1268                 break;
1269
1270         case I2C_MAX_FAST_MODE_PLUS_FREQ:
1271                 config_idx = MLXBF_I2C_TIMING_CONFIG_1000KHZ;
1272                 break;
1273         }
1274
1275         mlxbf_i2c_set_timings(priv, &mlxbf_i2c_timings[config_idx]);
1276
1277         return 0;
1278 }
1279
1280 static int mlxbf_i2c_get_gpio(struct platform_device *pdev,
1281                               struct mlxbf_i2c_priv *priv)
1282 {
1283         struct mlxbf_i2c_resource *gpio_res;
1284         struct device *dev = &pdev->dev;
1285         struct resource *params;
1286         resource_size_t size;
1287
1288         gpio_res = mlxbf_i2c_get_shared_resource(priv, MLXBF_I2C_GPIO_RES);
1289         if (!gpio_res)
1290                 return -EPERM;
1291
1292         /*
1293          * The GPIO region in TYU space is shared among I2C busses.
1294          * This function MUST be serialized to avoid racing when
1295          * claiming the memory region and/or setting up the GPIO.
1296          */
1297         lockdep_assert_held(gpio_res->lock);
1298
1299         /* Check whether the memory map exist. */
1300         if (gpio_res->io)
1301                 return 0;
1302
1303         params = gpio_res->params;
1304         size = resource_size(params);
1305
1306         if (!devm_request_mem_region(dev, params->start, size, params->name))
1307                 return -EFAULT;
1308
1309         gpio_res->io = devm_ioremap(dev, params->start, size);
1310         if (!gpio_res->io) {
1311                 devm_release_mem_region(dev, params->start, size);
1312                 return -ENOMEM;
1313         }
1314
1315         return 0;
1316 }
1317
1318 static int mlxbf_i2c_release_gpio(struct platform_device *pdev,
1319                                   struct mlxbf_i2c_priv *priv)
1320 {
1321         struct mlxbf_i2c_resource *gpio_res;
1322         struct device *dev = &pdev->dev;
1323         struct resource *params;
1324
1325         gpio_res = mlxbf_i2c_get_shared_resource(priv, MLXBF_I2C_GPIO_RES);
1326         if (!gpio_res)
1327                 return 0;
1328
1329         mutex_lock(gpio_res->lock);
1330
1331         if (gpio_res->io) {
1332                 /* Release the GPIO resource. */
1333                 params = gpio_res->params;
1334                 devm_iounmap(dev, gpio_res->io);
1335                 devm_release_mem_region(dev, params->start,
1336                                         resource_size(params));
1337         }
1338
1339         mutex_unlock(gpio_res->lock);
1340
1341         return 0;
1342 }
1343
1344 static int mlxbf_i2c_get_corepll(struct platform_device *pdev,
1345                                  struct mlxbf_i2c_priv *priv)
1346 {
1347         struct mlxbf_i2c_resource *corepll_res;
1348         struct device *dev = &pdev->dev;
1349         struct resource *params;
1350         resource_size_t size;
1351
1352         corepll_res = mlxbf_i2c_get_shared_resource(priv,
1353                                                     MLXBF_I2C_COREPLL_RES);
1354         if (!corepll_res)
1355                 return -EPERM;
1356
1357         /*
1358          * The COREPLL region in TYU space is shared among I2C busses.
1359          * This function MUST be serialized to avoid racing when
1360          * claiming the memory region.
1361          */
1362         lockdep_assert_held(corepll_res->lock);
1363
1364         /* Check whether the memory map exist. */
1365         if (corepll_res->io)
1366                 return 0;
1367
1368         params = corepll_res->params;
1369         size = resource_size(params);
1370
1371         if (!devm_request_mem_region(dev, params->start, size, params->name))
1372                 return -EFAULT;
1373
1374         corepll_res->io = devm_ioremap(dev, params->start, size);
1375         if (!corepll_res->io) {
1376                 devm_release_mem_region(dev, params->start, size);
1377                 return -ENOMEM;
1378         }
1379
1380         return 0;
1381 }
1382
1383 static int mlxbf_i2c_release_corepll(struct platform_device *pdev,
1384                                      struct mlxbf_i2c_priv *priv)
1385 {
1386         struct mlxbf_i2c_resource *corepll_res;
1387         struct device *dev = &pdev->dev;
1388         struct resource *params;
1389
1390         corepll_res = mlxbf_i2c_get_shared_resource(priv,
1391                                                     MLXBF_I2C_COREPLL_RES);
1392
1393         mutex_lock(corepll_res->lock);
1394
1395         if (corepll_res->io) {
1396                 /* Release the CorePLL resource. */
1397                 params = corepll_res->params;
1398                 devm_iounmap(dev, corepll_res->io);
1399                 devm_release_mem_region(dev, params->start,
1400                                         resource_size(params));
1401         }
1402
1403         mutex_unlock(corepll_res->lock);
1404
1405         return 0;
1406 }
1407
1408 static int mlxbf_i2c_init_master(struct platform_device *pdev,
1409                                  struct mlxbf_i2c_priv *priv)
1410 {
1411         struct mlxbf_i2c_resource *gpio_res;
1412         struct device *dev = &pdev->dev;
1413         u32 config_reg;
1414         int ret;
1415
1416         /* This configuration is only needed for BlueField 1. */
1417         if (!mlxbf_i2c_has_chip_type(priv, MLXBF_I2C_CHIP_TYPE_1))
1418                 return 0;
1419
1420         gpio_res = mlxbf_i2c_get_shared_resource(priv, MLXBF_I2C_GPIO_RES);
1421         if (!gpio_res)
1422                 return -EPERM;
1423
1424         /*
1425          * The GPIO region in TYU space is shared among I2C busses.
1426          * This function MUST be serialized to avoid racing when
1427          * claiming the memory region and/or setting up the GPIO.
1428          */
1429
1430         mutex_lock(gpio_res->lock);
1431
1432         ret = mlxbf_i2c_get_gpio(pdev, priv);
1433         if (ret < 0) {
1434                 dev_err(dev, "Failed to get gpio resource");
1435                 mutex_unlock(gpio_res->lock);
1436                 return ret;
1437         }
1438
1439         /*
1440          * TYU - Configuration for GPIO pins. Those pins must be asserted in
1441          * MLXBF_I2C_GPIO_0_FUNC_EN_0, i.e. GPIO 0 is controlled by HW, and must
1442          * be reset in MLXBF_I2C_GPIO_0_FORCE_OE_EN, i.e. GPIO_OE will be driven
1443          * instead of HW_OE.
1444          * For now, we do not reset the GPIO state when the driver is removed.
1445          * First, it is not necessary to disable the bus since we are using
1446          * the same busses. Then, some busses might be shared among Linux and
1447          * platform firmware; disabling the bus might compromise the system
1448          * functionality.
1449          */
1450         config_reg = readl(gpio_res->io + MLXBF_I2C_GPIO_0_FUNC_EN_0);
1451         config_reg = MLXBF_I2C_GPIO_SMBUS_GW_ASSERT_PINS(priv->bus,
1452                                                          config_reg);
1453         writel(config_reg, gpio_res->io + MLXBF_I2C_GPIO_0_FUNC_EN_0);
1454
1455         config_reg = readl(gpio_res->io + MLXBF_I2C_GPIO_0_FORCE_OE_EN);
1456         config_reg = MLXBF_I2C_GPIO_SMBUS_GW_RESET_PINS(priv->bus,
1457                                                         config_reg);
1458         writel(config_reg, gpio_res->io + MLXBF_I2C_GPIO_0_FORCE_OE_EN);
1459
1460         mutex_unlock(gpio_res->lock);
1461
1462         return 0;
1463 }
1464
1465 static u64 mlxbf_i2c_calculate_freq_from_tyu(struct mlxbf_i2c_resource *corepll_res)
1466 {
1467         u64 core_frequency;
1468         u8 core_od, core_r;
1469         u32 corepll_val;
1470         u16 core_f;
1471
1472         corepll_val = readl(corepll_res->io + MLXBF_I2C_CORE_PLL_REG1);
1473
1474         /* Get Core PLL configuration bits. */
1475         core_f = FIELD_GET(MLXBF_I2C_COREPLL_CORE_F_TYU_MASK, corepll_val);
1476         core_od = FIELD_GET(MLXBF_I2C_COREPLL_CORE_OD_TYU_MASK, corepll_val);
1477         core_r = FIELD_GET(MLXBF_I2C_COREPLL_CORE_R_TYU_MASK, corepll_val);
1478
1479         /*
1480          * Compute PLL output frequency as follow:
1481          *
1482          *                                       CORE_F + 1
1483          * PLL_OUT_FREQ = PLL_IN_FREQ * ----------------------------
1484          *                              (CORE_R + 1) * (CORE_OD + 1)
1485          *
1486          * Where PLL_OUT_FREQ and PLL_IN_FREQ refer to CoreFrequency
1487          * and PadFrequency, respectively.
1488          */
1489         core_frequency = MLXBF_I2C_PLL_IN_FREQ * (++core_f);
1490         core_frequency /= (++core_r) * (++core_od);
1491
1492         return core_frequency;
1493 }
1494
1495 static u64 mlxbf_i2c_calculate_freq_from_yu(struct mlxbf_i2c_resource *corepll_res)
1496 {
1497         u32 corepll_reg1_val, corepll_reg2_val;
1498         u64 corepll_frequency;
1499         u8 core_od, core_r;
1500         u32 core_f;
1501
1502         corepll_reg1_val = readl(corepll_res->io + MLXBF_I2C_CORE_PLL_REG1);
1503         corepll_reg2_val = readl(corepll_res->io + MLXBF_I2C_CORE_PLL_REG2);
1504
1505         /* Get Core PLL configuration bits */
1506         core_f = FIELD_GET(MLXBF_I2C_COREPLL_CORE_F_YU_MASK, corepll_reg1_val);
1507         core_r = FIELD_GET(MLXBF_I2C_COREPLL_CORE_R_YU_MASK, corepll_reg1_val);
1508         core_od = FIELD_GET(MLXBF_I2C_COREPLL_CORE_OD_YU_MASK, corepll_reg2_val);
1509
1510         /*
1511          * Compute PLL output frequency as follow:
1512          *
1513          *                                     CORE_F / 16384
1514          * PLL_OUT_FREQ = PLL_IN_FREQ * ----------------------------
1515          *                              (CORE_R + 1) * (CORE_OD + 1)
1516          *
1517          * Where PLL_OUT_FREQ and PLL_IN_FREQ refer to CoreFrequency
1518          * and PadFrequency, respectively.
1519          */
1520         corepll_frequency = (MLXBF_I2C_PLL_IN_FREQ * core_f) / MLNXBF_I2C_COREPLL_CONST;
1521         corepll_frequency /= (++core_r) * (++core_od);
1522
1523         return corepll_frequency;
1524 }
1525
1526 static int mlxbf_i2c_calculate_corepll_freq(struct platform_device *pdev,
1527                                             struct mlxbf_i2c_priv *priv)
1528 {
1529         const struct mlxbf_i2c_chip_info *chip = priv->chip;
1530         struct mlxbf_i2c_resource *corepll_res;
1531         struct device *dev = &pdev->dev;
1532         u64 *freq = &priv->frequency;
1533         int ret;
1534
1535         corepll_res = mlxbf_i2c_get_shared_resource(priv,
1536                                                     MLXBF_I2C_COREPLL_RES);
1537         if (!corepll_res)
1538                 return -EPERM;
1539
1540         /*
1541          * First, check whether the TYU core Clock frequency is set.
1542          * The TYU core frequency is the same for all I2C busses; when
1543          * the first device gets probed the frequency is determined and
1544          * stored into a globally visible variable. So, first of all,
1545          * check whether the frequency is already set. Here, we assume
1546          * that the frequency is expected to be greater than 0.
1547          */
1548         mutex_lock(corepll_res->lock);
1549         if (!mlxbf_i2c_corepll_frequency) {
1550                 if (!chip->calculate_freq) {
1551                         mutex_unlock(corepll_res->lock);
1552                         return -EPERM;
1553                 }
1554
1555                 ret = mlxbf_i2c_get_corepll(pdev, priv);
1556                 if (ret < 0) {
1557                         dev_err(dev, "Failed to get corePLL resource");
1558                         mutex_unlock(corepll_res->lock);
1559                         return ret;
1560                 }
1561
1562                 mlxbf_i2c_corepll_frequency = chip->calculate_freq(corepll_res);
1563         }
1564         mutex_unlock(corepll_res->lock);
1565
1566         *freq = mlxbf_i2c_corepll_frequency;
1567
1568         return 0;
1569 }
1570
1571 static int mlxbf_i2c_slave_enable(struct mlxbf_i2c_priv *priv,
1572                               struct i2c_client *slave)
1573 {
1574         u8 reg, reg_cnt, byte, addr_tmp;
1575         u32 slave_reg, slave_reg_tmp;
1576
1577         if (!priv)
1578                 return -EPERM;
1579
1580         reg_cnt = MLXBF_I2C_SMBUS_SLAVE_ADDR_CNT >> 2;
1581
1582         /*
1583          * Read the slave registers. There are 4 * 32-bit slave registers.
1584          * Each slave register can hold up to 4 * 8-bit slave configuration:
1585          * 1) A 7-bit address
1586          * 2) And a status bit (1 if enabled, 0 if not).
1587          * Look for the next available slave register slot.
1588          */
1589         for (reg = 0; reg < reg_cnt; reg++) {
1590                 slave_reg = readl(priv->slv->io +
1591                                 MLXBF_I2C_SMBUS_SLAVE_ADDR_CFG + reg * 0x4);
1592                 /*
1593                  * Each register holds 4 slave addresses. So, we have to keep
1594                  * the byte order consistent with the value read in order to
1595                  * update the register correctly, if needed.
1596                  */
1597                 slave_reg_tmp = slave_reg;
1598                 for (byte = 0; byte < 4; byte++) {
1599                         addr_tmp = slave_reg_tmp & GENMASK(7, 0);
1600
1601                         /*
1602                          * If an enable bit is not set in the
1603                          * MLXBF_I2C_SMBUS_SLAVE_ADDR_CFG register, then the
1604                          * slave address slot associated with that bit is
1605                          * free. So set the enable bit and write the
1606                          * slave address bits.
1607                          */
1608                         if (!(addr_tmp & MLXBF_I2C_SMBUS_SLAVE_ADDR_EN_BIT)) {
1609                                 slave_reg &= ~(MLXBF_I2C_SMBUS_SLAVE_ADDR_MASK << (byte * 8));
1610                                 slave_reg |= (slave->addr << (byte * 8));
1611                                 slave_reg |= MLXBF_I2C_SMBUS_SLAVE_ADDR_EN_BIT << (byte * 8);
1612                                 writel(slave_reg, priv->slv->io +
1613                                         MLXBF_I2C_SMBUS_SLAVE_ADDR_CFG +
1614                                         (reg * 0x4));
1615
1616                                 /*
1617                                  * Set the slave at the corresponding index.
1618                                  */
1619                                 priv->slave[(reg * 4) + byte] = slave;
1620
1621                                 return 0;
1622                         }
1623
1624                         /* Parse next byte. */
1625                         slave_reg_tmp >>= 8;
1626                 }
1627         }
1628
1629         return -EBUSY;
1630 }
1631
1632 static int mlxbf_i2c_slave_disable(struct mlxbf_i2c_priv *priv, u8 addr)
1633 {
1634         u8 addr_tmp, reg, reg_cnt, byte;
1635         u32 slave_reg, slave_reg_tmp;
1636
1637         reg_cnt = MLXBF_I2C_SMBUS_SLAVE_ADDR_CNT >> 2;
1638
1639         /*
1640          * Read the slave registers. There are 4 * 32-bit slave registers.
1641          * Each slave register can hold up to 4 * 8-bit slave configuration:
1642          * 1) A 7-bit address
1643          * 2) And a status bit (1 if enabled, 0 if not).
1644          * Check if addr is present in the registers.
1645          */
1646         for (reg = 0; reg < reg_cnt; reg++) {
1647                 slave_reg = readl(priv->slv->io +
1648                                 MLXBF_I2C_SMBUS_SLAVE_ADDR_CFG + reg * 0x4);
1649
1650                 /* Check whether the address slots are empty. */
1651                 if (!slave_reg)
1652                         continue;
1653
1654                 /*
1655                  * Check if addr matches any of the 4 slave addresses
1656                  * in the register.
1657                  */
1658                 slave_reg_tmp = slave_reg;
1659                 for (byte = 0; byte < 4; byte++) {
1660                         addr_tmp = slave_reg_tmp & MLXBF_I2C_SMBUS_SLAVE_ADDR_MASK;
1661                         /*
1662                          * Parse slave address bytes and check whether the
1663                          * slave address already exists.
1664                          */
1665                         if (addr_tmp == addr) {
1666                                 /* Clear the slave address slot. */
1667                                 slave_reg &= ~(GENMASK(7, 0) << (byte * 8));
1668                                 writel(slave_reg, priv->slv->io +
1669                                         MLXBF_I2C_SMBUS_SLAVE_ADDR_CFG +
1670                                         (reg * 0x4));
1671                                 /* Free slave at the corresponding index */
1672                                 priv->slave[(reg * 4) + byte] = NULL;
1673
1674                                 return 0;
1675                         }
1676
1677                         /* Parse next byte. */
1678                         slave_reg_tmp >>= 8;
1679                 }
1680         }
1681
1682         return -ENXIO;
1683 }
1684
1685 static int mlxbf_i2c_init_coalesce(struct platform_device *pdev,
1686                                    struct mlxbf_i2c_priv *priv)
1687 {
1688         struct mlxbf_i2c_resource *coalesce_res;
1689         struct resource *params;
1690         resource_size_t size;
1691         int ret = 0;
1692
1693         /*
1694          * Unlike BlueField-1 platform, the coalesce registers is a dedicated
1695          * resource in the next generations of BlueField.
1696          */
1697         if (mlxbf_i2c_has_chip_type(priv, MLXBF_I2C_CHIP_TYPE_1)) {
1698                 coalesce_res = mlxbf_i2c_get_shared_resource(priv,
1699                                                 MLXBF_I2C_COALESCE_RES);
1700                 if (!coalesce_res)
1701                         return -EPERM;
1702
1703                 /*
1704                  * The Cause Coalesce group in TYU space is shared among
1705                  * I2C busses. This function MUST be serialized to avoid
1706                  * racing when claiming the memory region.
1707                  */
1708                 lockdep_assert_held(mlxbf_i2c_gpio_res->lock);
1709
1710                 /* Check whether the memory map exist. */
1711                 if (coalesce_res->io) {
1712                         priv->coalesce = coalesce_res;
1713                         return 0;
1714                 }
1715
1716                 params = coalesce_res->params;
1717                 size = resource_size(params);
1718
1719                 if (!request_mem_region(params->start, size, params->name))
1720                         return -EFAULT;
1721
1722                 coalesce_res->io = ioremap(params->start, size);
1723                 if (!coalesce_res->io) {
1724                         release_mem_region(params->start, size);
1725                         return -ENOMEM;
1726                 }
1727
1728                 priv->coalesce = coalesce_res;
1729
1730         } else {
1731                 ret = mlxbf_i2c_init_resource(pdev, &priv->coalesce,
1732                                               MLXBF_I2C_COALESCE_RES);
1733         }
1734
1735         return ret;
1736 }
1737
1738 static int mlxbf_i2c_release_coalesce(struct platform_device *pdev,
1739                                       struct mlxbf_i2c_priv *priv)
1740 {
1741         struct mlxbf_i2c_resource *coalesce_res;
1742         struct device *dev = &pdev->dev;
1743         struct resource *params;
1744         resource_size_t size;
1745
1746         coalesce_res = priv->coalesce;
1747
1748         if (coalesce_res->io) {
1749                 params = coalesce_res->params;
1750                 size = resource_size(params);
1751                 if (mlxbf_i2c_has_chip_type(priv, MLXBF_I2C_CHIP_TYPE_1)) {
1752                         mutex_lock(coalesce_res->lock);
1753                         iounmap(coalesce_res->io);
1754                         release_mem_region(params->start, size);
1755                         mutex_unlock(coalesce_res->lock);
1756                 } else {
1757                         devm_release_mem_region(dev, params->start, size);
1758                 }
1759         }
1760
1761         return 0;
1762 }
1763
1764 static int mlxbf_i2c_init_slave(struct platform_device *pdev,
1765                                 struct mlxbf_i2c_priv *priv)
1766 {
1767         struct device *dev = &pdev->dev;
1768         u32 int_reg;
1769         int ret;
1770
1771         /* Reset FSM. */
1772         writel(0, priv->slv->io + MLXBF_I2C_SMBUS_SLAVE_FSM);
1773
1774         /*
1775          * Enable slave cause interrupt bits. Drive
1776          * MLXBF_I2C_CAUSE_READ_WAIT_FW_RESPONSE and
1777          * MLXBF_I2C_CAUSE_WRITE_SUCCESS, these are enabled when an external
1778          * masters issue a Read and Write, respectively. But, clear all
1779          * interrupts first.
1780          */
1781         writel(~0, priv->slv_cause->io + MLXBF_I2C_CAUSE_OR_CLEAR);
1782         int_reg = MLXBF_I2C_CAUSE_READ_WAIT_FW_RESPONSE;
1783         int_reg |= MLXBF_I2C_CAUSE_WRITE_SUCCESS;
1784         writel(int_reg, priv->slv_cause->io + MLXBF_I2C_CAUSE_OR_EVTEN0);
1785
1786         /* Finally, set the 'ready' bit to start handling transactions. */
1787         writel(0x1, priv->slv->io + MLXBF_I2C_SMBUS_SLAVE_READY);
1788
1789         /* Initialize the cause coalesce resource. */
1790         ret = mlxbf_i2c_init_coalesce(pdev, priv);
1791         if (ret < 0) {
1792                 dev_err(dev, "failed to initialize cause coalesce\n");
1793                 return ret;
1794         }
1795
1796         return 0;
1797 }
1798
1799 static bool mlxbf_i2c_has_coalesce(struct mlxbf_i2c_priv *priv, bool *read,
1800                                    bool *write)
1801 {
1802         const struct mlxbf_i2c_chip_info *chip = priv->chip;
1803         u32 coalesce0_reg, cause_reg;
1804         u8 slave_shift, is_set;
1805
1806         *write = false;
1807         *read = false;
1808
1809         slave_shift = chip->type != MLXBF_I2C_CHIP_TYPE_1 ?
1810                                 MLXBF_I2C_CAUSE_YU_SLAVE_BIT :
1811                                 priv->bus + MLXBF_I2C_CAUSE_TYU_SLAVE_BIT;
1812
1813         coalesce0_reg = readl(priv->coalesce->io + MLXBF_I2C_CAUSE_COALESCE_0);
1814         is_set = coalesce0_reg & (1 << slave_shift);
1815
1816         if (!is_set)
1817                 return false;
1818
1819         /* Check the source of the interrupt, i.e. whether a Read or Write. */
1820         cause_reg = readl(priv->slv_cause->io + MLXBF_I2C_CAUSE_ARBITER);
1821         if (cause_reg & MLXBF_I2C_CAUSE_READ_WAIT_FW_RESPONSE)
1822                 *read = true;
1823         else if (cause_reg & MLXBF_I2C_CAUSE_WRITE_SUCCESS)
1824                 *write = true;
1825
1826         /* Clear cause bits. */
1827         writel(~0x0, priv->slv_cause->io + MLXBF_I2C_CAUSE_OR_CLEAR);
1828
1829         return true;
1830 }
1831
1832 static bool mlxbf_i2c_slave_wait_for_idle(struct mlxbf_i2c_priv *priv,
1833                                             u32 timeout)
1834 {
1835         u32 mask = MLXBF_I2C_CAUSE_S_GW_BUSY_FALL;
1836         u32 addr = MLXBF_I2C_CAUSE_ARBITER;
1837
1838         if (mlxbf_i2c_poll(priv->slv_cause->io, addr, mask, false, timeout))
1839                 return true;
1840
1841         return false;
1842 }
1843
1844 static struct i2c_client *mlxbf_i2c_get_slave_from_addr(
1845                         struct mlxbf_i2c_priv *priv, u8 addr)
1846 {
1847         int i;
1848
1849         for (i = 0; i < MLXBF_I2C_SMBUS_SLAVE_ADDR_CNT; i++) {
1850                 if (!priv->slave[i])
1851                         continue;
1852
1853                 if (priv->slave[i]->addr == addr)
1854                         return priv->slave[i];
1855         }
1856
1857         return NULL;
1858 }
1859
1860 /*
1861  * Send byte to 'external' smbus master. This function is executed when
1862  * an external smbus master wants to read data from the BlueField.
1863  */
1864 static int mlxbf_i2c_irq_send(struct mlxbf_i2c_priv *priv, u8 recv_bytes)
1865 {
1866         u8 data_desc[MLXBF_I2C_SLAVE_DATA_DESC_SIZE] = { 0 };
1867         u8 write_size, pec_en, addr, value, byte_cnt;
1868         struct i2c_client *slave;
1869         u32 control32, data32;
1870         int ret = 0;
1871
1872         /*
1873          * Read the first byte received from the external master to
1874          * determine the slave address. This byte is located in the
1875          * first data descriptor register of the slave GW.
1876          */
1877         data32 = ioread32be(priv->slv->io +
1878                                 MLXBF_I2C_SLAVE_DATA_DESC_ADDR);
1879         addr = (data32 & GENMASK(7, 0)) >> 1;
1880
1881         /*
1882          * Check if the slave address received in the data descriptor register
1883          * matches any of the slave addresses registered. If there is a match,
1884          * set the slave.
1885          */
1886         slave = mlxbf_i2c_get_slave_from_addr(priv, addr);
1887         if (!slave) {
1888                 ret = -ENXIO;
1889                 goto clear_csr;
1890         }
1891
1892         /*
1893          * An I2C read can consist of a WRITE bit transaction followed by
1894          * a READ bit transaction. Indeed, slave devices often expect
1895          * the slave address to be followed by the internal address.
1896          * So, write the internal address byte first, and then, send the
1897          * requested data to the master.
1898          */
1899         if (recv_bytes > 1) {
1900                 i2c_slave_event(slave, I2C_SLAVE_WRITE_REQUESTED, &value);
1901                 value = (data32 >> 8) & GENMASK(7, 0);
1902                 ret = i2c_slave_event(slave, I2C_SLAVE_WRITE_RECEIVED,
1903                                       &value);
1904                 i2c_slave_event(slave, I2C_SLAVE_STOP, &value);
1905
1906                 if (ret < 0)
1907                         goto clear_csr;
1908         }
1909
1910         /*
1911          * Send data to the master. Currently, the driver supports
1912          * READ_BYTE, READ_WORD and BLOCK READ protocols. The
1913          * hardware can send up to 128 bytes per transfer which is
1914          * the total size of the data registers.
1915          */
1916         i2c_slave_event(slave, I2C_SLAVE_READ_REQUESTED, &value);
1917
1918         for (byte_cnt = 0; byte_cnt < MLXBF_I2C_SLAVE_DATA_DESC_SIZE; byte_cnt++) {
1919                 data_desc[byte_cnt] = value;
1920                 i2c_slave_event(slave, I2C_SLAVE_READ_PROCESSED, &value);
1921         }
1922
1923         /* Send a stop condition to the backend. */
1924         i2c_slave_event(slave, I2C_SLAVE_STOP, &value);
1925
1926         /* Set the number of bytes to write to master. */
1927         write_size = (byte_cnt - 1) & 0x7f;
1928
1929         /* Write data to Slave GW data descriptor. */
1930         mlxbf_i2c_smbus_write_data(priv, data_desc, byte_cnt,
1931                                    MLXBF_I2C_SLAVE_DATA_DESC_ADDR, false);
1932
1933         pec_en = 0; /* Disable PEC since it is not supported. */
1934
1935         /* Prepare control word. */
1936         control32 = MLXBF_I2C_SLAVE_ENABLE;
1937         control32 |= rol32(write_size, MLXBF_I2C_SLAVE_WRITE_BYTES_SHIFT);
1938         control32 |= rol32(pec_en, MLXBF_I2C_SLAVE_SEND_PEC_SHIFT);
1939
1940         writel(control32, priv->slv->io + MLXBF_I2C_SMBUS_SLAVE_GW);
1941
1942         /*
1943          * Wait until the transfer is completed; the driver will wait
1944          * until the GW is idle, a cause will rise on fall of GW busy.
1945          */
1946         mlxbf_i2c_slave_wait_for_idle(priv, MLXBF_I2C_SMBUS_TIMEOUT);
1947
1948 clear_csr:
1949         /* Release the Slave GW. */
1950         writel(0x0, priv->slv->io + MLXBF_I2C_SMBUS_SLAVE_RS_MASTER_BYTES);
1951         writel(0x0, priv->slv->io + MLXBF_I2C_SMBUS_SLAVE_PEC);
1952         writel(0x1, priv->slv->io + MLXBF_I2C_SMBUS_SLAVE_READY);
1953
1954         return ret;
1955 }
1956
1957 /*
1958  * Receive bytes from 'external' smbus master. This function is executed when
1959  * an external smbus master wants to write data to the BlueField.
1960  */
1961 static int mlxbf_i2c_irq_recv(struct mlxbf_i2c_priv *priv, u8 recv_bytes)
1962 {
1963         u8 data_desc[MLXBF_I2C_SLAVE_DATA_DESC_SIZE] = { 0 };
1964         struct i2c_client *slave;
1965         u8 value, byte, addr;
1966         int ret = 0;
1967
1968         /* Read data from Slave GW data descriptor. */
1969         mlxbf_i2c_smbus_read_data(priv, data_desc, recv_bytes,
1970                                   MLXBF_I2C_SLAVE_DATA_DESC_ADDR, false);
1971         addr = data_desc[0] >> 1;
1972
1973         /*
1974          * Check if the slave address received in the data descriptor register
1975          * matches any of the slave addresses registered.
1976          */
1977         slave = mlxbf_i2c_get_slave_from_addr(priv, addr);
1978         if (!slave) {
1979                 ret = -EINVAL;
1980                 goto clear_csr;
1981         }
1982
1983         /*
1984          * Notify the slave backend that an smbus master wants to write data
1985          * to the BlueField.
1986          */
1987         i2c_slave_event(slave, I2C_SLAVE_WRITE_REQUESTED, &value);
1988
1989         /* Send the received data to the slave backend. */
1990         for (byte = 1; byte < recv_bytes; byte++) {
1991                 value = data_desc[byte];
1992                 ret = i2c_slave_event(slave, I2C_SLAVE_WRITE_RECEIVED,
1993                                       &value);
1994                 if (ret < 0)
1995                         break;
1996         }
1997
1998         /*
1999          * Send a stop event to the slave backend, to signal
2000          * the end of the write transactions.
2001          */
2002         i2c_slave_event(slave, I2C_SLAVE_STOP, &value);
2003
2004 clear_csr:
2005         /* Release the Slave GW. */
2006         writel(0x0, priv->slv->io + MLXBF_I2C_SMBUS_SLAVE_RS_MASTER_BYTES);
2007         writel(0x0, priv->slv->io + MLXBF_I2C_SMBUS_SLAVE_PEC);
2008         writel(0x1, priv->slv->io + MLXBF_I2C_SMBUS_SLAVE_READY);
2009
2010         return ret;
2011 }
2012
2013 static irqreturn_t mlxbf_i2c_irq(int irq, void *ptr)
2014 {
2015         struct mlxbf_i2c_priv *priv = ptr;
2016         bool read, write, irq_is_set;
2017         u32 rw_bytes_reg;
2018         u8 recv_bytes;
2019
2020         /*
2021          * Read TYU interrupt register and determine the source of the
2022          * interrupt. Based on the source of the interrupt one of the
2023          * following actions are performed:
2024          *  - Receive data and send response to master.
2025          *  - Send data and release slave GW.
2026          *
2027          * Handle read/write transaction only. CRmaster and Iarp requests
2028          * are ignored for now.
2029          */
2030         irq_is_set = mlxbf_i2c_has_coalesce(priv, &read, &write);
2031         if (!irq_is_set || (!read && !write)) {
2032                 /* Nothing to do here, interrupt was not from this device. */
2033                 return IRQ_NONE;
2034         }
2035
2036         /*
2037          * The MLXBF_I2C_SMBUS_SLAVE_RS_MASTER_BYTES includes the number of
2038          * bytes from/to master. These are defined by 8-bits each. If the lower
2039          * 8 bits are set, then the master expect to read N bytes from the
2040          * slave, if the higher 8 bits are sent then the slave expect N bytes
2041          * from the master.
2042          */
2043         rw_bytes_reg = readl(priv->slv->io +
2044                                 MLXBF_I2C_SMBUS_SLAVE_RS_MASTER_BYTES);
2045         recv_bytes = (rw_bytes_reg >> 8) & GENMASK(7, 0);
2046
2047         /*
2048          * For now, the slave supports 128 bytes transfer. Discard remaining
2049          * data bytes if the master wrote more than
2050          * MLXBF_I2C_SLAVE_DATA_DESC_SIZE, i.e, the actual size of the slave
2051          * data descriptor.
2052          *
2053          * Note that we will never expect to transfer more than 128 bytes; as
2054          * specified in the SMBus standard, block transactions cannot exceed
2055          * 32 bytes.
2056          */
2057         recv_bytes = recv_bytes > MLXBF_I2C_SLAVE_DATA_DESC_SIZE ?
2058                 MLXBF_I2C_SLAVE_DATA_DESC_SIZE : recv_bytes;
2059
2060         if (read)
2061                 mlxbf_i2c_irq_send(priv, recv_bytes);
2062         else
2063                 mlxbf_i2c_irq_recv(priv, recv_bytes);
2064
2065         return IRQ_HANDLED;
2066 }
2067
2068 /* Return negative errno on error. */
2069 static s32 mlxbf_i2c_smbus_xfer(struct i2c_adapter *adap, u16 addr,
2070                                 unsigned short flags, char read_write,
2071                                 u8 command, int size,
2072                                 union i2c_smbus_data *data)
2073 {
2074         struct mlxbf_i2c_smbus_request request = { 0 };
2075         struct mlxbf_i2c_priv *priv;
2076         bool read, pec;
2077         u8 byte_cnt;
2078
2079         request.slave = addr;
2080
2081         read = (read_write == I2C_SMBUS_READ);
2082         pec = flags & I2C_FUNC_SMBUS_PEC;
2083
2084         switch (size) {
2085         case I2C_SMBUS_QUICK:
2086                 mlxbf_i2c_smbus_quick_command(&request, read);
2087                 dev_dbg(&adap->dev, "smbus quick, slave 0x%02x\n", addr);
2088                 break;
2089
2090         case I2C_SMBUS_BYTE:
2091                 mlxbf_i2c_smbus_byte_func(&request,
2092                                           read ? &data->byte : &command, read,
2093                                           pec);
2094                 dev_dbg(&adap->dev, "smbus %s byte, slave 0x%02x.\n",
2095                         read ? "read" : "write", addr);
2096                 break;
2097
2098         case I2C_SMBUS_BYTE_DATA:
2099                 mlxbf_i2c_smbus_data_byte_func(&request, &command, &data->byte,
2100                                                read, pec);
2101                 dev_dbg(&adap->dev, "smbus %s byte data at 0x%02x, slave 0x%02x.\n",
2102                         read ? "read" : "write", command, addr);
2103                 break;
2104
2105         case I2C_SMBUS_WORD_DATA:
2106                 mlxbf_i2c_smbus_data_word_func(&request, &command,
2107                                                (u8 *)&data->word, read, pec);
2108                 dev_dbg(&adap->dev, "smbus %s word data at 0x%02x, slave 0x%02x.\n",
2109                         read ? "read" : "write", command, addr);
2110                 break;
2111
2112         case I2C_SMBUS_I2C_BLOCK_DATA:
2113                 byte_cnt = data->block[0];
2114                 mlxbf_i2c_smbus_i2c_block_func(&request, &command, data->block,
2115                                                &byte_cnt, read, pec);
2116                 dev_dbg(&adap->dev, "i2c %s block data, %d bytes at 0x%02x, slave 0x%02x.\n",
2117                         read ? "read" : "write", byte_cnt, command, addr);
2118                 break;
2119
2120         case I2C_SMBUS_BLOCK_DATA:
2121                 byte_cnt = read ? I2C_SMBUS_BLOCK_MAX : data->block[0];
2122                 mlxbf_i2c_smbus_block_func(&request, &command, data->block,
2123                                            &byte_cnt, read, pec);
2124                 dev_dbg(&adap->dev, "smbus %s block data, %d bytes at 0x%02x, slave 0x%02x.\n",
2125                         read ? "read" : "write", byte_cnt, command, addr);
2126                 break;
2127
2128         case I2C_FUNC_SMBUS_PROC_CALL:
2129                 mlxbf_i2c_smbus_process_call_func(&request, &command,
2130                                                   (u8 *)&data->word, pec);
2131                 dev_dbg(&adap->dev, "process call, wr/rd at 0x%02x, slave 0x%02x.\n",
2132                         command, addr);
2133                 break;
2134
2135         case I2C_FUNC_SMBUS_BLOCK_PROC_CALL:
2136                 byte_cnt = data->block[0];
2137                 mlxbf_i2c_smbus_blk_process_call_func(&request, &command,
2138                                                       data->block, &byte_cnt,
2139                                                       pec);
2140                 dev_dbg(&adap->dev, "block process call, wr/rd %d bytes, slave 0x%02x.\n",
2141                         byte_cnt, addr);
2142                 break;
2143
2144         default:
2145                 dev_dbg(&adap->dev, "Unsupported I2C/SMBus command %d\n",
2146                         size);
2147                 return -EOPNOTSUPP;
2148         }
2149
2150         priv = i2c_get_adapdata(adap);
2151
2152         return mlxbf_i2c_smbus_start_transaction(priv, &request);
2153 }
2154
2155 static int mlxbf_i2c_reg_slave(struct i2c_client *slave)
2156 {
2157         struct mlxbf_i2c_priv *priv = i2c_get_adapdata(slave->adapter);
2158         struct device *dev = &slave->dev;
2159         int ret;
2160
2161         /*
2162          * Do not support ten bit chip address and do not use Packet Error
2163          * Checking (PEC).
2164          */
2165         if (slave->flags & (I2C_CLIENT_TEN | I2C_CLIENT_PEC)) {
2166                 dev_err(dev, "SMBus PEC and 10 bit address not supported\n");
2167                 return -EAFNOSUPPORT;
2168         }
2169
2170         ret = mlxbf_i2c_slave_enable(priv, slave);
2171         if (ret)
2172                 dev_err(dev, "Surpassed max number of registered slaves allowed\n");
2173
2174         return 0;
2175 }
2176
2177 static int mlxbf_i2c_unreg_slave(struct i2c_client *slave)
2178 {
2179         struct mlxbf_i2c_priv *priv = i2c_get_adapdata(slave->adapter);
2180         struct device *dev = &slave->dev;
2181         int ret;
2182
2183         /*
2184          * Unregister slave by:
2185          * 1) Disabling the slave address in hardware
2186          * 2) Freeing priv->slave at the corresponding index
2187          */
2188         ret = mlxbf_i2c_slave_disable(priv, slave->addr);
2189         if (ret)
2190                 dev_err(dev, "Unable to find slave 0x%x\n", slave->addr);
2191
2192         return ret;
2193 }
2194
2195 static u32 mlxbf_i2c_functionality(struct i2c_adapter *adap)
2196 {
2197         return MLXBF_I2C_FUNC_ALL;
2198 }
2199
2200 static struct mlxbf_i2c_chip_info mlxbf_i2c_chip[] = {
2201         [MLXBF_I2C_CHIP_TYPE_1] = {
2202                 .type = MLXBF_I2C_CHIP_TYPE_1,
2203                 .shared_res = {
2204                         [0] = &mlxbf_i2c_coalesce_res[MLXBF_I2C_CHIP_TYPE_1],
2205                         [1] = &mlxbf_i2c_corepll_res[MLXBF_I2C_CHIP_TYPE_1],
2206                         [2] = &mlxbf_i2c_gpio_res[MLXBF_I2C_CHIP_TYPE_1]
2207                 },
2208                 .calculate_freq = mlxbf_i2c_calculate_freq_from_tyu,
2209                 .smbus_master_rs_bytes_off = MLXBF_I2C_YU_SMBUS_RS_BYTES,
2210                 .smbus_master_fsm_off = MLXBF_I2C_YU_SMBUS_MASTER_FSM
2211         },
2212         [MLXBF_I2C_CHIP_TYPE_2] = {
2213                 .type = MLXBF_I2C_CHIP_TYPE_2,
2214                 .shared_res = {
2215                         [0] = &mlxbf_i2c_corepll_res[MLXBF_I2C_CHIP_TYPE_2]
2216                 },
2217                 .calculate_freq = mlxbf_i2c_calculate_freq_from_yu,
2218                 .smbus_master_rs_bytes_off = MLXBF_I2C_YU_SMBUS_RS_BYTES,
2219                 .smbus_master_fsm_off = MLXBF_I2C_YU_SMBUS_MASTER_FSM
2220         },
2221         [MLXBF_I2C_CHIP_TYPE_3] = {
2222                 .type = MLXBF_I2C_CHIP_TYPE_3,
2223                 .shared_res = {
2224                         [0] = &mlxbf_i2c_corepll_res[MLXBF_I2C_CHIP_TYPE_3]
2225                 },
2226                 .calculate_freq = mlxbf_i2c_calculate_freq_from_yu,
2227                 .smbus_master_rs_bytes_off = MLXBF_I2C_RSH_YU_SMBUS_RS_BYTES,
2228                 .smbus_master_fsm_off = MLXBF_I2C_RSH_YU_SMBUS_MASTER_FSM
2229         }
2230 };
2231
2232 static const struct i2c_algorithm mlxbf_i2c_algo = {
2233         .smbus_xfer = mlxbf_i2c_smbus_xfer,
2234         .functionality = mlxbf_i2c_functionality,
2235         .reg_slave = mlxbf_i2c_reg_slave,
2236         .unreg_slave = mlxbf_i2c_unreg_slave,
2237 };
2238
2239 static struct i2c_adapter_quirks mlxbf_i2c_quirks = {
2240         .max_read_len = MLXBF_I2C_MASTER_DATA_R_LENGTH,
2241         .max_write_len = MLXBF_I2C_MASTER_DATA_W_LENGTH,
2242 };
2243
2244 static const struct acpi_device_id mlxbf_i2c_acpi_ids[] = {
2245         { "MLNXBF03", (kernel_ulong_t)&mlxbf_i2c_chip[MLXBF_I2C_CHIP_TYPE_1] },
2246         { "MLNXBF23", (kernel_ulong_t)&mlxbf_i2c_chip[MLXBF_I2C_CHIP_TYPE_2] },
2247         { "MLNXBF31", (kernel_ulong_t)&mlxbf_i2c_chip[MLXBF_I2C_CHIP_TYPE_3] },
2248         {},
2249 };
2250
2251 MODULE_DEVICE_TABLE(acpi, mlxbf_i2c_acpi_ids);
2252
2253 static int mlxbf_i2c_acpi_probe(struct device *dev, struct mlxbf_i2c_priv *priv)
2254 {
2255         const struct acpi_device_id *aid;
2256         u64 bus_id;
2257         int ret;
2258
2259         if (acpi_disabled)
2260                 return -ENOENT;
2261
2262         aid = acpi_match_device(mlxbf_i2c_acpi_ids, dev);
2263         if (!aid)
2264                 return -ENODEV;
2265
2266         priv->chip = (struct mlxbf_i2c_chip_info *)aid->driver_data;
2267
2268         ret = acpi_dev_uid_to_integer(ACPI_COMPANION(dev), &bus_id);
2269         if (ret) {
2270                 dev_err(dev, "Cannot retrieve UID\n");
2271                 return ret;
2272         }
2273
2274         priv->bus = bus_id;
2275
2276         return 0;
2277 }
2278
2279 static int mlxbf_i2c_probe(struct platform_device *pdev)
2280 {
2281         struct device *dev = &pdev->dev;
2282         struct mlxbf_i2c_priv *priv;
2283         struct i2c_adapter *adap;
2284         u32 resource_version;
2285         int irq, ret;
2286
2287         priv = devm_kzalloc(dev, sizeof(struct mlxbf_i2c_priv), GFP_KERNEL);
2288         if (!priv)
2289                 return -ENOMEM;
2290
2291         ret = mlxbf_i2c_acpi_probe(dev, priv);
2292         if (ret < 0)
2293                 return ret;
2294
2295         /* This property allows the driver to stay backward compatible with older
2296          * ACPI tables.
2297          * Starting BlueField-3 SoC, the "smbus" resource was broken down into 3
2298          * separate resources "timer", "master" and "slave".
2299          */
2300         if (device_property_read_u32(dev, "resource_version", &resource_version))
2301                 resource_version = 0;
2302
2303         priv->resource_version = resource_version;
2304
2305         if (priv->chip->type < MLXBF_I2C_CHIP_TYPE_3 && resource_version == 0) {
2306                 priv->timer = devm_kzalloc(dev, sizeof(struct mlxbf_i2c_resource), GFP_KERNEL);
2307                 if (!priv->timer)
2308                         return -ENOMEM;
2309
2310                 priv->mst = devm_kzalloc(dev, sizeof(struct mlxbf_i2c_resource), GFP_KERNEL);
2311                 if (!priv->mst)
2312                         return -ENOMEM;
2313
2314                 priv->slv = devm_kzalloc(dev, sizeof(struct mlxbf_i2c_resource), GFP_KERNEL);
2315                 if (!priv->slv)
2316                         return -ENOMEM;
2317
2318                 ret = mlxbf_i2c_init_resource(pdev, &priv->smbus,
2319                                               MLXBF_I2C_SMBUS_RES);
2320                 if (ret < 0)
2321                         return dev_err_probe(dev, ret, "Cannot fetch smbus resource info");
2322
2323                 priv->timer->io = priv->smbus->io;
2324                 priv->mst->io = priv->smbus->io + MLXBF_I2C_MST_ADDR_OFFSET;
2325                 priv->slv->io = priv->smbus->io + MLXBF_I2C_SLV_ADDR_OFFSET;
2326         } else {
2327                 ret = mlxbf_i2c_init_resource(pdev, &priv->timer,
2328                                               MLXBF_I2C_SMBUS_TIMER_RES);
2329                 if (ret < 0)
2330                         return dev_err_probe(dev, ret, "Cannot fetch timer resource info");
2331
2332                 ret = mlxbf_i2c_init_resource(pdev, &priv->mst,
2333                                               MLXBF_I2C_SMBUS_MST_RES);
2334                 if (ret < 0)
2335                         return dev_err_probe(dev, ret, "Cannot fetch master resource info");
2336
2337                 ret = mlxbf_i2c_init_resource(pdev, &priv->slv,
2338                                               MLXBF_I2C_SMBUS_SLV_RES);
2339                 if (ret < 0)
2340                         return dev_err_probe(dev, ret, "Cannot fetch slave resource info");
2341         }
2342
2343         ret = mlxbf_i2c_init_resource(pdev, &priv->mst_cause,
2344                                       MLXBF_I2C_MST_CAUSE_RES);
2345         if (ret < 0)
2346                 return dev_err_probe(dev, ret, "Cannot fetch cause master resource info");
2347
2348         ret = mlxbf_i2c_init_resource(pdev, &priv->slv_cause,
2349                                       MLXBF_I2C_SLV_CAUSE_RES);
2350         if (ret < 0)
2351                 return dev_err_probe(dev, ret, "Cannot fetch cause slave resource info");
2352
2353         adap = &priv->adap;
2354         adap->owner = THIS_MODULE;
2355         adap->class = I2C_CLASS_HWMON;
2356         adap->algo = &mlxbf_i2c_algo;
2357         adap->quirks = &mlxbf_i2c_quirks;
2358         adap->dev.parent = dev;
2359         adap->dev.of_node = dev->of_node;
2360         adap->nr = priv->bus;
2361
2362         snprintf(adap->name, sizeof(adap->name), "i2c%d", adap->nr);
2363         i2c_set_adapdata(adap, priv);
2364
2365         /* Read Core PLL frequency. */
2366         ret = mlxbf_i2c_calculate_corepll_freq(pdev, priv);
2367         if (ret < 0) {
2368                 dev_err(dev, "cannot get core clock frequency\n");
2369                 /* Set to default value. */
2370                 priv->frequency = MLXBF_I2C_COREPLL_FREQ;
2371         }
2372
2373         /*
2374          * Initialize master.
2375          * Note that a physical bus might be shared among Linux and firmware
2376          * (e.g., ATF). Thus, the bus should be initialized and ready and
2377          * bus initialization would be unnecessary. This requires additional
2378          * knowledge about physical busses. But, since an extra initialization
2379          * does not really hurt, then keep the code as is.
2380          */
2381         ret = mlxbf_i2c_init_master(pdev, priv);
2382         if (ret < 0)
2383                 return dev_err_probe(dev, ret, "failed to initialize smbus master %d",
2384                                      priv->bus);
2385
2386         mlxbf_i2c_init_timings(pdev, priv);
2387
2388         mlxbf_i2c_init_slave(pdev, priv);
2389
2390         irq = platform_get_irq(pdev, 0);
2391         if (irq < 0)
2392                 return irq;
2393         ret = devm_request_irq(dev, irq, mlxbf_i2c_irq,
2394                                IRQF_SHARED | IRQF_PROBE_SHARED,
2395                                dev_name(dev), priv);
2396         if (ret < 0)
2397                 return dev_err_probe(dev, ret, "Cannot get irq %d\n", irq);
2398
2399         priv->irq = irq;
2400
2401         platform_set_drvdata(pdev, priv);
2402
2403         ret = i2c_add_numbered_adapter(adap);
2404         if (ret < 0)
2405                 return ret;
2406
2407         mutex_lock(&mlxbf_i2c_bus_lock);
2408         mlxbf_i2c_bus_count++;
2409         mutex_unlock(&mlxbf_i2c_bus_lock);
2410
2411         return 0;
2412 }
2413
2414 static void mlxbf_i2c_remove(struct platform_device *pdev)
2415 {
2416         struct mlxbf_i2c_priv *priv = platform_get_drvdata(pdev);
2417         struct device *dev = &pdev->dev;
2418         struct resource *params;
2419
2420         if (priv->chip->type < MLXBF_I2C_CHIP_TYPE_3 && priv->resource_version == 0) {
2421                 params = priv->smbus->params;
2422                 devm_release_mem_region(dev, params->start, resource_size(params));
2423         } else {
2424                 params = priv->timer->params;
2425                 devm_release_mem_region(dev, params->start, resource_size(params));
2426
2427                 params = priv->mst->params;
2428                 devm_release_mem_region(dev, params->start, resource_size(params));
2429
2430                 params = priv->slv->params;
2431                 devm_release_mem_region(dev, params->start, resource_size(params));
2432         }
2433
2434         params = priv->mst_cause->params;
2435         devm_release_mem_region(dev, params->start, resource_size(params));
2436
2437         params = priv->slv_cause->params;
2438         devm_release_mem_region(dev, params->start, resource_size(params));
2439
2440         /*
2441          * Release shared resources. This should be done when releasing
2442          * the I2C controller.
2443          */
2444         mutex_lock(&mlxbf_i2c_bus_lock);
2445         if (--mlxbf_i2c_bus_count == 0) {
2446                 mlxbf_i2c_release_coalesce(pdev, priv);
2447                 mlxbf_i2c_release_corepll(pdev, priv);
2448                 mlxbf_i2c_release_gpio(pdev, priv);
2449         }
2450         mutex_unlock(&mlxbf_i2c_bus_lock);
2451
2452         devm_free_irq(dev, priv->irq, priv);
2453
2454         i2c_del_adapter(&priv->adap);
2455 }
2456
2457 static struct platform_driver mlxbf_i2c_driver = {
2458         .probe = mlxbf_i2c_probe,
2459         .remove_new = mlxbf_i2c_remove,
2460         .driver = {
2461                 .name = "i2c-mlxbf",
2462                 .acpi_match_table = ACPI_PTR(mlxbf_i2c_acpi_ids),
2463         },
2464 };
2465
2466 static int __init mlxbf_i2c_init(void)
2467 {
2468         mutex_init(&mlxbf_i2c_coalesce_lock);
2469         mutex_init(&mlxbf_i2c_corepll_lock);
2470         mutex_init(&mlxbf_i2c_gpio_lock);
2471
2472         mutex_init(&mlxbf_i2c_bus_lock);
2473
2474         return platform_driver_register(&mlxbf_i2c_driver);
2475 }
2476 module_init(mlxbf_i2c_init);
2477
2478 static void __exit mlxbf_i2c_exit(void)
2479 {
2480         platform_driver_unregister(&mlxbf_i2c_driver);
2481
2482         mutex_destroy(&mlxbf_i2c_bus_lock);
2483
2484         mutex_destroy(&mlxbf_i2c_gpio_lock);
2485         mutex_destroy(&mlxbf_i2c_corepll_lock);
2486         mutex_destroy(&mlxbf_i2c_coalesce_lock);
2487 }
2488 module_exit(mlxbf_i2c_exit);
2489
2490 MODULE_DESCRIPTION("Mellanox BlueField I2C bus driver");
2491 MODULE_AUTHOR("Khalil Blaiech <kblaiech@nvidia.com>");
2492 MODULE_AUTHOR("Asmaa Mnebhi <asmaa@nvidia.com>");
2493 MODULE_LICENSE("GPL v2");