1 // SPDX-License-Identifier: GPL-2.0
3 * Driver for STMicroelectronics STM32F7 I2C controller
5 * This I2C controller is described in the STM32F75xxx and STM32F74xxx Soc
7 * Please see below a link to the documentation:
8 * http://www.st.com/resource/en/reference_manual/dm00124865.pdf
10 * Copyright (C) M'boumba Cedric Madianga 2017
11 * Copyright (C) STMicroelectronics 2017
12 * Author: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
14 * This driver is based on i2c-stm32f4.c
17 #include <linux/clk.h>
18 #include <linux/delay.h>
19 #include <linux/err.h>
20 #include <linux/i2c.h>
21 #include <linux/interrupt.h>
23 #include <linux/iopoll.h>
24 #include <linux/module.h>
26 #include <linux/of_address.h>
27 #include <linux/of_platform.h>
28 #include <linux/platform_device.h>
29 #include <linux/reset.h>
30 #include <linux/slab.h>
32 #include "i2c-stm32.h"
34 /* STM32F7 I2C registers */
35 #define STM32F7_I2C_CR1 0x00
36 #define STM32F7_I2C_CR2 0x04
37 #define STM32F7_I2C_OAR1 0x08
38 #define STM32F7_I2C_OAR2 0x0C
39 #define STM32F7_I2C_PECR 0x20
40 #define STM32F7_I2C_TIMINGR 0x10
41 #define STM32F7_I2C_ISR 0x18
42 #define STM32F7_I2C_ICR 0x1C
43 #define STM32F7_I2C_RXDR 0x24
44 #define STM32F7_I2C_TXDR 0x28
46 /* STM32F7 I2C control 1 */
47 #define STM32F7_I2C_CR1_PECEN BIT(23)
48 #define STM32F7_I2C_CR1_SBC BIT(16)
49 #define STM32F7_I2C_CR1_RXDMAEN BIT(15)
50 #define STM32F7_I2C_CR1_TXDMAEN BIT(14)
51 #define STM32F7_I2C_CR1_ANFOFF BIT(12)
52 #define STM32F7_I2C_CR1_DNF_MASK GENMASK(11, 8)
53 #define STM32F7_I2C_CR1_DNF(n) (((n) & 0xf) << 8)
54 #define STM32F7_I2C_CR1_ERRIE BIT(7)
55 #define STM32F7_I2C_CR1_TCIE BIT(6)
56 #define STM32F7_I2C_CR1_STOPIE BIT(5)
57 #define STM32F7_I2C_CR1_NACKIE BIT(4)
58 #define STM32F7_I2C_CR1_ADDRIE BIT(3)
59 #define STM32F7_I2C_CR1_RXIE BIT(2)
60 #define STM32F7_I2C_CR1_TXIE BIT(1)
61 #define STM32F7_I2C_CR1_PE BIT(0)
62 #define STM32F7_I2C_ALL_IRQ_MASK (STM32F7_I2C_CR1_ERRIE \
63 | STM32F7_I2C_CR1_TCIE \
64 | STM32F7_I2C_CR1_STOPIE \
65 | STM32F7_I2C_CR1_NACKIE \
66 | STM32F7_I2C_CR1_RXIE \
67 | STM32F7_I2C_CR1_TXIE)
68 #define STM32F7_I2C_XFER_IRQ_MASK (STM32F7_I2C_CR1_TCIE \
69 | STM32F7_I2C_CR1_STOPIE \
70 | STM32F7_I2C_CR1_NACKIE \
71 | STM32F7_I2C_CR1_RXIE \
72 | STM32F7_I2C_CR1_TXIE)
74 /* STM32F7 I2C control 2 */
75 #define STM32F7_I2C_CR2_PECBYTE BIT(26)
76 #define STM32F7_I2C_CR2_RELOAD BIT(24)
77 #define STM32F7_I2C_CR2_NBYTES_MASK GENMASK(23, 16)
78 #define STM32F7_I2C_CR2_NBYTES(n) (((n) & 0xff) << 16)
79 #define STM32F7_I2C_CR2_NACK BIT(15)
80 #define STM32F7_I2C_CR2_STOP BIT(14)
81 #define STM32F7_I2C_CR2_START BIT(13)
82 #define STM32F7_I2C_CR2_HEAD10R BIT(12)
83 #define STM32F7_I2C_CR2_ADD10 BIT(11)
84 #define STM32F7_I2C_CR2_RD_WRN BIT(10)
85 #define STM32F7_I2C_CR2_SADD10_MASK GENMASK(9, 0)
86 #define STM32F7_I2C_CR2_SADD10(n) (((n) & \
87 STM32F7_I2C_CR2_SADD10_MASK))
88 #define STM32F7_I2C_CR2_SADD7_MASK GENMASK(7, 1)
89 #define STM32F7_I2C_CR2_SADD7(n) (((n) & 0x7f) << 1)
91 /* STM32F7 I2C Own Address 1 */
92 #define STM32F7_I2C_OAR1_OA1EN BIT(15)
93 #define STM32F7_I2C_OAR1_OA1MODE BIT(10)
94 #define STM32F7_I2C_OAR1_OA1_10_MASK GENMASK(9, 0)
95 #define STM32F7_I2C_OAR1_OA1_10(n) (((n) & \
96 STM32F7_I2C_OAR1_OA1_10_MASK))
97 #define STM32F7_I2C_OAR1_OA1_7_MASK GENMASK(7, 1)
98 #define STM32F7_I2C_OAR1_OA1_7(n) (((n) & 0x7f) << 1)
99 #define STM32F7_I2C_OAR1_MASK (STM32F7_I2C_OAR1_OA1_7_MASK \
100 | STM32F7_I2C_OAR1_OA1_10_MASK \
101 | STM32F7_I2C_OAR1_OA1EN \
102 | STM32F7_I2C_OAR1_OA1MODE)
104 /* STM32F7 I2C Own Address 2 */
105 #define STM32F7_I2C_OAR2_OA2EN BIT(15)
106 #define STM32F7_I2C_OAR2_OA2MSK_MASK GENMASK(10, 8)
107 #define STM32F7_I2C_OAR2_OA2MSK(n) (((n) & 0x7) << 8)
108 #define STM32F7_I2C_OAR2_OA2_7_MASK GENMASK(7, 1)
109 #define STM32F7_I2C_OAR2_OA2_7(n) (((n) & 0x7f) << 1)
110 #define STM32F7_I2C_OAR2_MASK (STM32F7_I2C_OAR2_OA2MSK_MASK \
111 | STM32F7_I2C_OAR2_OA2_7_MASK \
112 | STM32F7_I2C_OAR2_OA2EN)
114 /* STM32F7 I2C Interrupt Status */
115 #define STM32F7_I2C_ISR_ADDCODE_MASK GENMASK(23, 17)
116 #define STM32F7_I2C_ISR_ADDCODE_GET(n) \
117 (((n) & STM32F7_I2C_ISR_ADDCODE_MASK) >> 17)
118 #define STM32F7_I2C_ISR_DIR BIT(16)
119 #define STM32F7_I2C_ISR_BUSY BIT(15)
120 #define STM32F7_I2C_ISR_PECERR BIT(11)
121 #define STM32F7_I2C_ISR_ARLO BIT(9)
122 #define STM32F7_I2C_ISR_BERR BIT(8)
123 #define STM32F7_I2C_ISR_TCR BIT(7)
124 #define STM32F7_I2C_ISR_TC BIT(6)
125 #define STM32F7_I2C_ISR_STOPF BIT(5)
126 #define STM32F7_I2C_ISR_NACKF BIT(4)
127 #define STM32F7_I2C_ISR_ADDR BIT(3)
128 #define STM32F7_I2C_ISR_RXNE BIT(2)
129 #define STM32F7_I2C_ISR_TXIS BIT(1)
130 #define STM32F7_I2C_ISR_TXE BIT(0)
132 /* STM32F7 I2C Interrupt Clear */
133 #define STM32F7_I2C_ICR_PECCF BIT(11)
134 #define STM32F7_I2C_ICR_ARLOCF BIT(9)
135 #define STM32F7_I2C_ICR_BERRCF BIT(8)
136 #define STM32F7_I2C_ICR_STOPCF BIT(5)
137 #define STM32F7_I2C_ICR_NACKCF BIT(4)
138 #define STM32F7_I2C_ICR_ADDRCF BIT(3)
140 /* STM32F7 I2C Timing */
141 #define STM32F7_I2C_TIMINGR_PRESC(n) (((n) & 0xf) << 28)
142 #define STM32F7_I2C_TIMINGR_SCLDEL(n) (((n) & 0xf) << 20)
143 #define STM32F7_I2C_TIMINGR_SDADEL(n) (((n) & 0xf) << 16)
144 #define STM32F7_I2C_TIMINGR_SCLH(n) (((n) & 0xff) << 8)
145 #define STM32F7_I2C_TIMINGR_SCLL(n) ((n) & 0xff)
147 #define STM32F7_I2C_MAX_LEN 0xff
148 #define STM32F7_I2C_DMA_LEN_MIN 0x16
149 #define STM32F7_I2C_MAX_SLAVE 0x2
151 #define STM32F7_I2C_DNF_DEFAULT 0
152 #define STM32F7_I2C_DNF_MAX 15
154 #define STM32F7_I2C_ANALOG_FILTER_ENABLE 1
155 #define STM32F7_I2C_ANALOG_FILTER_DELAY_MIN 50 /* ns */
156 #define STM32F7_I2C_ANALOG_FILTER_DELAY_MAX 260 /* ns */
158 #define STM32F7_I2C_RISE_TIME_DEFAULT 25 /* ns */
159 #define STM32F7_I2C_FALL_TIME_DEFAULT 10 /* ns */
161 #define STM32F7_PRESC_MAX BIT(4)
162 #define STM32F7_SCLDEL_MAX BIT(4)
163 #define STM32F7_SDADEL_MAX BIT(4)
164 #define STM32F7_SCLH_MAX BIT(8)
165 #define STM32F7_SCLL_MAX BIT(8)
168 * struct stm32f7_i2c_spec - private i2c specification timing
169 * @rate: I2C bus speed (Hz)
170 * @rate_min: 80% of I2C bus speed (Hz)
171 * @rate_max: 100% of I2C bus speed (Hz)
172 * @fall_max: Max fall time of both SDA and SCL signals (ns)
173 * @rise_max: Max rise time of both SDA and SCL signals (ns)
174 * @hddat_min: Min data hold time (ns)
175 * @vddat_max: Max data valid time (ns)
176 * @sudat_min: Min data setup time (ns)
177 * @l_min: Min low period of the SCL clock (ns)
178 * @h_min: Min high period of the SCL clock (ns)
180 struct stm32f7_i2c_spec {
194 * struct stm32f7_i2c_setup - private I2C timing setup parameters
195 * @speed: I2C speed mode (standard, Fast Plus)
196 * @speed_freq: I2C speed frequency (Hz)
197 * @clock_src: I2C clock source frequency (Hz)
198 * @rise_time: Rise time (ns)
199 * @fall_time: Fall time (ns)
200 * @dnf: Digital filter coefficient (0-16)
201 * @analog_filter: Analog filter delay (On/Off)
203 struct stm32f7_i2c_setup {
204 enum stm32_i2c_speed speed;
214 * struct stm32f7_i2c_timings - private I2C output parameters
216 * @presc: Prescaler value
217 * @scldel: Data setup time
218 * @sdadel: Data hold time
219 * @sclh: SCL high period (master mode)
220 * @scll: SCL low period (master mode)
222 struct stm32f7_i2c_timings {
223 struct list_head node;
232 * struct stm32f7_i2c_msg - client specific data
233 * @addr: 8-bit or 10-bit slave addr, including r/w bit
234 * @count: number of bytes to be transferred
236 * @result: result of the transfer
237 * @stop: last I2C msg to be sent, i.e. STOP to be generated
238 * @smbus: boolean to know if the I2C IP is used in SMBus mode
239 * @size: type of SMBus protocol
240 * @read_write: direction of SMBus protocol
241 * SMBus block read and SMBus block write - block read process call protocols
242 * @smbus_buf: buffer to be used for SMBus protocol transfer. It will
243 * contain a maximum of 32 bytes of data + byte command + byte count + PEC
244 * This buffer has to be 32-bit aligned to be compliant with memory address
245 * register in DMA mode.
247 struct stm32f7_i2c_msg {
256 u8 smbus_buf[I2C_SMBUS_BLOCK_MAX + 3] __aligned(4);
260 * struct stm32f7_i2c_dev - private data of the controller
261 * @adap: I2C adapter for this controller
262 * @dev: device for this controller
263 * @base: virtual memory area
264 * @complete: completion of I2C message
266 * @speed: I2C clock frequency of the controller. Standard, Fast or Fast+
267 * @msg: Pointer to data to be written
268 * @msg_num: number of I2C messages to be executed
269 * @msg_id: message identifiant
270 * @f7_msg: customized i2c msg for driver usage
271 * @setup: I2C timing input setup
272 * @timing: I2C computed timings
273 * @slave: list of slave devices registered on the I2C bus
274 * @slave_running: slave device currently used
275 * @slave_dir: transfer direction for the current slave device
276 * @master_mode: boolean to know in which mode the I2C is running (master or
279 * @use_dma: boolean to know if dma is used in the current transfer
281 struct stm32f7_i2c_dev {
282 struct i2c_adapter adap;
285 struct completion complete;
289 unsigned int msg_num;
291 struct stm32f7_i2c_msg f7_msg;
292 struct stm32f7_i2c_setup setup;
293 struct stm32f7_i2c_timings timing;
294 struct i2c_client *slave[STM32F7_I2C_MAX_SLAVE];
295 struct i2c_client *slave_running;
298 struct stm32_i2c_dma *dma;
303 * All these values are coming from I2C Specification, Version 6.0, 4th of
306 * Table10. Characteristics of the SDA and SCL bus lines for Standard, Fast,
307 * and Fast-mode Plus I2C-bus devices
309 static struct stm32f7_i2c_spec i2c_specs[] = {
310 [STM32_I2C_SPEED_STANDARD] = {
322 [STM32_I2C_SPEED_FAST] = {
334 [STM32_I2C_SPEED_FAST_PLUS] = {
348 static const struct stm32f7_i2c_setup stm32f7_setup = {
349 .rise_time = STM32F7_I2C_RISE_TIME_DEFAULT,
350 .fall_time = STM32F7_I2C_FALL_TIME_DEFAULT,
351 .dnf = STM32F7_I2C_DNF_DEFAULT,
352 .analog_filter = STM32F7_I2C_ANALOG_FILTER_ENABLE,
355 static inline void stm32f7_i2c_set_bits(void __iomem *reg, u32 mask)
357 writel_relaxed(readl_relaxed(reg) | mask, reg);
360 static inline void stm32f7_i2c_clr_bits(void __iomem *reg, u32 mask)
362 writel_relaxed(readl_relaxed(reg) & ~mask, reg);
365 static void stm32f7_i2c_disable_irq(struct stm32f7_i2c_dev *i2c_dev, u32 mask)
367 stm32f7_i2c_clr_bits(i2c_dev->base + STM32F7_I2C_CR1, mask);
370 static int stm32f7_i2c_compute_timing(struct stm32f7_i2c_dev *i2c_dev,
371 struct stm32f7_i2c_setup *setup,
372 struct stm32f7_i2c_timings *output)
374 u32 p_prev = STM32F7_PRESC_MAX;
375 u32 i2cclk = DIV_ROUND_CLOSEST(NSEC_PER_SEC,
377 u32 i2cbus = DIV_ROUND_CLOSEST(NSEC_PER_SEC,
379 u32 clk_error_prev = i2cbus;
381 u32 af_delay_min, af_delay_max;
383 u32 clk_min, clk_max;
384 int sdadel_min, sdadel_max;
386 struct stm32f7_i2c_timings *v, *_v, *s;
387 struct list_head solutions;
391 if (setup->speed >= STM32_I2C_SPEED_END) {
392 dev_err(i2c_dev->dev, "speed out of bound {%d/%d}\n",
393 setup->speed, STM32_I2C_SPEED_END - 1);
397 if ((setup->rise_time > i2c_specs[setup->speed].rise_max) ||
398 (setup->fall_time > i2c_specs[setup->speed].fall_max)) {
399 dev_err(i2c_dev->dev,
400 "timings out of bound Rise{%d>%d}/Fall{%d>%d}\n",
401 setup->rise_time, i2c_specs[setup->speed].rise_max,
402 setup->fall_time, i2c_specs[setup->speed].fall_max);
406 if (setup->dnf > STM32F7_I2C_DNF_MAX) {
407 dev_err(i2c_dev->dev,
408 "DNF out of bound %d/%d\n",
409 setup->dnf, STM32F7_I2C_DNF_MAX);
413 if (setup->speed_freq > i2c_specs[setup->speed].rate) {
414 dev_err(i2c_dev->dev, "ERROR: Freq {%d/%d}\n",
415 setup->speed_freq, i2c_specs[setup->speed].rate);
419 /* Analog and Digital Filters */
421 (setup->analog_filter ?
422 STM32F7_I2C_ANALOG_FILTER_DELAY_MIN : 0);
424 (setup->analog_filter ?
425 STM32F7_I2C_ANALOG_FILTER_DELAY_MAX : 0);
426 dnf_delay = setup->dnf * i2cclk;
428 sdadel_min = i2c_specs[setup->speed].hddat_min + setup->fall_time -
429 af_delay_min - (setup->dnf + 3) * i2cclk;
431 sdadel_max = i2c_specs[setup->speed].vddat_max - setup->rise_time -
432 af_delay_max - (setup->dnf + 4) * i2cclk;
434 scldel_min = setup->rise_time + i2c_specs[setup->speed].sudat_min;
441 dev_dbg(i2c_dev->dev, "SDADEL(min/max): %i/%i, SCLDEL(Min): %i\n",
442 sdadel_min, sdadel_max, scldel_min);
444 INIT_LIST_HEAD(&solutions);
445 /* Compute possible values for PRESC, SCLDEL and SDADEL */
446 for (p = 0; p < STM32F7_PRESC_MAX; p++) {
447 for (l = 0; l < STM32F7_SCLDEL_MAX; l++) {
448 u32 scldel = (l + 1) * (p + 1) * i2cclk;
450 if (scldel < scldel_min)
453 for (a = 0; a < STM32F7_SDADEL_MAX; a++) {
454 u32 sdadel = (a * (p + 1) + 1) * i2cclk;
456 if (((sdadel >= sdadel_min) &&
457 (sdadel <= sdadel_max)) &&
459 v = kmalloc(sizeof(*v), GFP_KERNEL);
470 list_add_tail(&v->node,
477 if (list_empty(&solutions)) {
478 dev_err(i2c_dev->dev, "no Prescaler solution\n");
483 tsync = af_delay_min + dnf_delay + (2 * i2cclk);
485 clk_max = NSEC_PER_SEC / i2c_specs[setup->speed].rate_min;
486 clk_min = NSEC_PER_SEC / i2c_specs[setup->speed].rate_max;
489 * Among Prescaler possibilities discovered above figures out SCL Low
490 * and High Period. Provided:
491 * - SCL Low Period has to be higher than SCL Clock Low Period
492 * defined by I2C Specification. I2C Clock has to be lower than
493 * (SCL Low Period - Analog/Digital filters) / 4.
494 * - SCL High Period has to be lower than SCL Clock High Period
495 * defined by I2C Specification
496 * - I2C Clock has to be lower than SCL High Period
498 list_for_each_entry(v, &solutions, node) {
499 u32 prescaler = (v->presc + 1) * i2cclk;
501 for (l = 0; l < STM32F7_SCLL_MAX; l++) {
502 u32 tscl_l = (l + 1) * prescaler + tsync;
504 if ((tscl_l < i2c_specs[setup->speed].l_min) ||
506 ((tscl_l - af_delay_min - dnf_delay) / 4))) {
510 for (h = 0; h < STM32F7_SCLH_MAX; h++) {
511 u32 tscl_h = (h + 1) * prescaler + tsync;
512 u32 tscl = tscl_l + tscl_h +
513 setup->rise_time + setup->fall_time;
515 if ((tscl >= clk_min) && (tscl <= clk_max) &&
516 (tscl_h >= i2c_specs[setup->speed].h_min) &&
518 int clk_error = tscl - i2cbus;
521 clk_error = -clk_error;
523 if (clk_error < clk_error_prev) {
524 clk_error_prev = clk_error;
535 dev_err(i2c_dev->dev, "no solution at all\n");
540 output->presc = s->presc;
541 output->scldel = s->scldel;
542 output->sdadel = s->sdadel;
543 output->scll = s->scll;
544 output->sclh = s->sclh;
546 dev_dbg(i2c_dev->dev,
547 "Presc: %i, scldel: %i, sdadel: %i, scll: %i, sclh: %i\n",
549 output->scldel, output->sdadel,
550 output->scll, output->sclh);
553 /* Release list and memory */
554 list_for_each_entry_safe(v, _v, &solutions, node) {
562 static int stm32f7_i2c_setup_timing(struct stm32f7_i2c_dev *i2c_dev,
563 struct stm32f7_i2c_setup *setup)
567 setup->speed = i2c_dev->speed;
568 setup->speed_freq = i2c_specs[setup->speed].rate;
569 setup->clock_src = clk_get_rate(i2c_dev->clk);
571 if (!setup->clock_src) {
572 dev_err(i2c_dev->dev, "clock rate is 0\n");
577 ret = stm32f7_i2c_compute_timing(i2c_dev, setup,
580 dev_err(i2c_dev->dev,
581 "failed to compute I2C timings.\n");
582 if (i2c_dev->speed > STM32_I2C_SPEED_STANDARD) {
584 setup->speed = i2c_dev->speed;
586 i2c_specs[setup->speed].rate;
587 dev_warn(i2c_dev->dev,
588 "downgrade I2C Speed Freq to (%i)\n",
589 i2c_specs[setup->speed].rate);
597 dev_err(i2c_dev->dev, "Impossible to compute I2C timings.\n");
601 dev_dbg(i2c_dev->dev, "I2C Speed(%i), Freq(%i), Clk Source(%i)\n",
602 setup->speed, setup->speed_freq, setup->clock_src);
603 dev_dbg(i2c_dev->dev, "I2C Rise(%i) and Fall(%i) Time\n",
604 setup->rise_time, setup->fall_time);
605 dev_dbg(i2c_dev->dev, "I2C Analog Filter(%s), DNF(%i)\n",
606 (setup->analog_filter ? "On" : "Off"), setup->dnf);
611 static void stm32f7_i2c_disable_dma_req(struct stm32f7_i2c_dev *i2c_dev)
613 void __iomem *base = i2c_dev->base;
614 u32 mask = STM32F7_I2C_CR1_RXDMAEN | STM32F7_I2C_CR1_TXDMAEN;
616 stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR1, mask);
619 static void stm32f7_i2c_dma_callback(void *arg)
621 struct stm32f7_i2c_dev *i2c_dev = (struct stm32f7_i2c_dev *)arg;
622 struct stm32_i2c_dma *dma = i2c_dev->dma;
623 struct device *dev = dma->chan_using->device->dev;
625 stm32f7_i2c_disable_dma_req(i2c_dev);
626 dma_unmap_single(dev, dma->dma_buf, dma->dma_len, dma->dma_data_dir);
627 complete(&dma->dma_complete);
630 static void stm32f7_i2c_hw_config(struct stm32f7_i2c_dev *i2c_dev)
632 struct stm32f7_i2c_timings *t = &i2c_dev->timing;
635 /* Timing settings */
636 timing |= STM32F7_I2C_TIMINGR_PRESC(t->presc);
637 timing |= STM32F7_I2C_TIMINGR_SCLDEL(t->scldel);
638 timing |= STM32F7_I2C_TIMINGR_SDADEL(t->sdadel);
639 timing |= STM32F7_I2C_TIMINGR_SCLH(t->sclh);
640 timing |= STM32F7_I2C_TIMINGR_SCLL(t->scll);
641 writel_relaxed(timing, i2c_dev->base + STM32F7_I2C_TIMINGR);
644 if (i2c_dev->setup.analog_filter)
645 stm32f7_i2c_clr_bits(i2c_dev->base + STM32F7_I2C_CR1,
646 STM32F7_I2C_CR1_ANFOFF);
648 stm32f7_i2c_set_bits(i2c_dev->base + STM32F7_I2C_CR1,
649 STM32F7_I2C_CR1_ANFOFF);
651 /* Program the Digital Filter */
652 stm32f7_i2c_clr_bits(i2c_dev->base + STM32F7_I2C_CR1,
653 STM32F7_I2C_CR1_DNF_MASK);
654 stm32f7_i2c_set_bits(i2c_dev->base + STM32F7_I2C_CR1,
655 STM32F7_I2C_CR1_DNF(i2c_dev->setup.dnf));
657 stm32f7_i2c_set_bits(i2c_dev->base + STM32F7_I2C_CR1,
661 static void stm32f7_i2c_write_tx_data(struct stm32f7_i2c_dev *i2c_dev)
663 struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
664 void __iomem *base = i2c_dev->base;
667 writeb_relaxed(*f7_msg->buf++, base + STM32F7_I2C_TXDR);
672 static void stm32f7_i2c_read_rx_data(struct stm32f7_i2c_dev *i2c_dev)
674 struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
675 void __iomem *base = i2c_dev->base;
678 *f7_msg->buf++ = readb_relaxed(base + STM32F7_I2C_RXDR);
681 /* Flush RX buffer has no data is expected */
682 readb_relaxed(base + STM32F7_I2C_RXDR);
686 static void stm32f7_i2c_reload(struct stm32f7_i2c_dev *i2c_dev)
688 struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
691 if (i2c_dev->use_dma)
692 f7_msg->count -= STM32F7_I2C_MAX_LEN;
694 cr2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_CR2);
696 cr2 &= ~STM32F7_I2C_CR2_NBYTES_MASK;
697 if (f7_msg->count > STM32F7_I2C_MAX_LEN) {
698 cr2 |= STM32F7_I2C_CR2_NBYTES(STM32F7_I2C_MAX_LEN);
700 cr2 &= ~STM32F7_I2C_CR2_RELOAD;
701 cr2 |= STM32F7_I2C_CR2_NBYTES(f7_msg->count);
704 writel_relaxed(cr2, i2c_dev->base + STM32F7_I2C_CR2);
707 static void stm32f7_i2c_smbus_reload(struct stm32f7_i2c_dev *i2c_dev)
709 struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
714 * For I2C_SMBUS_BLOCK_DATA && I2C_SMBUS_BLOCK_PROC_CALL, the first
715 * data received inform us how many data will follow.
717 stm32f7_i2c_read_rx_data(i2c_dev);
720 * Update NBYTES with the value read to continue the transfer
722 val = f7_msg->buf - sizeof(u8);
723 f7_msg->count = *val;
724 cr2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_CR2);
725 cr2 &= ~(STM32F7_I2C_CR2_NBYTES_MASK | STM32F7_I2C_CR2_RELOAD);
726 cr2 |= STM32F7_I2C_CR2_NBYTES(f7_msg->count);
727 writel_relaxed(cr2, i2c_dev->base + STM32F7_I2C_CR2);
730 static int stm32f7_i2c_release_bus(struct i2c_adapter *i2c_adap)
732 struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(i2c_adap);
734 dev_info(i2c_dev->dev, "Trying to recover bus\n");
736 stm32f7_i2c_clr_bits(i2c_dev->base + STM32F7_I2C_CR1,
739 stm32f7_i2c_hw_config(i2c_dev);
744 static int stm32f7_i2c_wait_free_bus(struct stm32f7_i2c_dev *i2c_dev)
749 ret = readl_relaxed_poll_timeout(i2c_dev->base + STM32F7_I2C_ISR,
751 !(status & STM32F7_I2C_ISR_BUSY),
756 dev_info(i2c_dev->dev, "bus busy\n");
758 ret = stm32f7_i2c_release_bus(&i2c_dev->adap);
760 dev_err(i2c_dev->dev, "Failed to recover the bus (%d)\n", ret);
767 static void stm32f7_i2c_xfer_msg(struct stm32f7_i2c_dev *i2c_dev,
770 struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
771 void __iomem *base = i2c_dev->base;
775 f7_msg->addr = msg->addr;
776 f7_msg->buf = msg->buf;
777 f7_msg->count = msg->len;
779 f7_msg->stop = (i2c_dev->msg_id >= i2c_dev->msg_num - 1);
781 reinit_completion(&i2c_dev->complete);
783 cr1 = readl_relaxed(base + STM32F7_I2C_CR1);
784 cr2 = readl_relaxed(base + STM32F7_I2C_CR2);
786 /* Set transfer direction */
787 cr2 &= ~STM32F7_I2C_CR2_RD_WRN;
788 if (msg->flags & I2C_M_RD)
789 cr2 |= STM32F7_I2C_CR2_RD_WRN;
791 /* Set slave address */
792 cr2 &= ~(STM32F7_I2C_CR2_HEAD10R | STM32F7_I2C_CR2_ADD10);
793 if (msg->flags & I2C_M_TEN) {
794 cr2 &= ~STM32F7_I2C_CR2_SADD10_MASK;
795 cr2 |= STM32F7_I2C_CR2_SADD10(f7_msg->addr);
796 cr2 |= STM32F7_I2C_CR2_ADD10;
798 cr2 &= ~STM32F7_I2C_CR2_SADD7_MASK;
799 cr2 |= STM32F7_I2C_CR2_SADD7(f7_msg->addr);
802 /* Set nb bytes to transfer and reload if needed */
803 cr2 &= ~(STM32F7_I2C_CR2_NBYTES_MASK | STM32F7_I2C_CR2_RELOAD);
804 if (f7_msg->count > STM32F7_I2C_MAX_LEN) {
805 cr2 |= STM32F7_I2C_CR2_NBYTES(STM32F7_I2C_MAX_LEN);
806 cr2 |= STM32F7_I2C_CR2_RELOAD;
808 cr2 |= STM32F7_I2C_CR2_NBYTES(f7_msg->count);
811 /* Enable NACK, STOP, error and transfer complete interrupts */
812 cr1 |= STM32F7_I2C_CR1_ERRIE | STM32F7_I2C_CR1_TCIE |
813 STM32F7_I2C_CR1_STOPIE | STM32F7_I2C_CR1_NACKIE;
815 /* Clear DMA req and TX/RX interrupt */
816 cr1 &= ~(STM32F7_I2C_CR1_RXIE | STM32F7_I2C_CR1_TXIE |
817 STM32F7_I2C_CR1_RXDMAEN | STM32F7_I2C_CR1_TXDMAEN);
819 /* Configure DMA or enable RX/TX interrupt */
820 i2c_dev->use_dma = false;
821 if (i2c_dev->dma && f7_msg->count >= STM32F7_I2C_DMA_LEN_MIN) {
822 ret = stm32_i2c_prep_dma_xfer(i2c_dev->dev, i2c_dev->dma,
823 msg->flags & I2C_M_RD,
824 f7_msg->count, f7_msg->buf,
825 stm32f7_i2c_dma_callback,
828 i2c_dev->use_dma = true;
830 dev_warn(i2c_dev->dev, "can't use DMA\n");
833 if (!i2c_dev->use_dma) {
834 if (msg->flags & I2C_M_RD)
835 cr1 |= STM32F7_I2C_CR1_RXIE;
837 cr1 |= STM32F7_I2C_CR1_TXIE;
839 if (msg->flags & I2C_M_RD)
840 cr1 |= STM32F7_I2C_CR1_RXDMAEN;
842 cr1 |= STM32F7_I2C_CR1_TXDMAEN;
845 /* Configure Start/Repeated Start */
846 cr2 |= STM32F7_I2C_CR2_START;
848 i2c_dev->master_mode = true;
850 /* Write configurations registers */
851 writel_relaxed(cr1, base + STM32F7_I2C_CR1);
852 writel_relaxed(cr2, base + STM32F7_I2C_CR2);
855 static int stm32f7_i2c_smbus_xfer_msg(struct stm32f7_i2c_dev *i2c_dev,
856 unsigned short flags, u8 command,
857 union i2c_smbus_data *data)
859 struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
860 struct device *dev = i2c_dev->dev;
861 void __iomem *base = i2c_dev->base;
866 reinit_completion(&i2c_dev->complete);
868 cr2 = readl_relaxed(base + STM32F7_I2C_CR2);
869 cr1 = readl_relaxed(base + STM32F7_I2C_CR1);
871 /* Set transfer direction */
872 cr2 &= ~STM32F7_I2C_CR2_RD_WRN;
873 if (f7_msg->read_write)
874 cr2 |= STM32F7_I2C_CR2_RD_WRN;
876 /* Set slave address */
877 cr2 &= ~(STM32F7_I2C_CR2_ADD10 | STM32F7_I2C_CR2_SADD7_MASK);
878 cr2 |= STM32F7_I2C_CR2_SADD7(f7_msg->addr);
880 f7_msg->smbus_buf[0] = command;
881 switch (f7_msg->size) {
882 case I2C_SMBUS_QUICK:
890 case I2C_SMBUS_BYTE_DATA:
891 if (f7_msg->read_write) {
892 f7_msg->stop = false;
894 cr2 &= ~STM32F7_I2C_CR2_RD_WRN;
898 f7_msg->smbus_buf[1] = data->byte;
901 case I2C_SMBUS_WORD_DATA:
902 if (f7_msg->read_write) {
903 f7_msg->stop = false;
905 cr2 &= ~STM32F7_I2C_CR2_RD_WRN;
909 f7_msg->smbus_buf[1] = data->word & 0xff;
910 f7_msg->smbus_buf[2] = data->word >> 8;
913 case I2C_SMBUS_BLOCK_DATA:
914 if (f7_msg->read_write) {
915 f7_msg->stop = false;
917 cr2 &= ~STM32F7_I2C_CR2_RD_WRN;
920 if (data->block[0] > I2C_SMBUS_BLOCK_MAX ||
922 dev_err(dev, "Invalid block write size %d\n",
926 f7_msg->count = data->block[0] + 2;
927 for (i = 1; i < f7_msg->count; i++)
928 f7_msg->smbus_buf[i] = data->block[i - 1];
931 case I2C_SMBUS_PROC_CALL:
932 f7_msg->stop = false;
934 f7_msg->smbus_buf[1] = data->word & 0xff;
935 f7_msg->smbus_buf[2] = data->word >> 8;
936 cr2 &= ~STM32F7_I2C_CR2_RD_WRN;
937 f7_msg->read_write = I2C_SMBUS_READ;
939 case I2C_SMBUS_BLOCK_PROC_CALL:
940 f7_msg->stop = false;
941 if (data->block[0] > I2C_SMBUS_BLOCK_MAX - 1) {
942 dev_err(dev, "Invalid block write size %d\n",
946 f7_msg->count = data->block[0] + 2;
947 for (i = 1; i < f7_msg->count; i++)
948 f7_msg->smbus_buf[i] = data->block[i - 1];
949 cr2 &= ~STM32F7_I2C_CR2_RD_WRN;
950 f7_msg->read_write = I2C_SMBUS_READ;
953 dev_err(dev, "Unsupported smbus protocol %d\n", f7_msg->size);
957 f7_msg->buf = f7_msg->smbus_buf;
960 if ((flags & I2C_CLIENT_PEC) && f7_msg->size != I2C_SMBUS_QUICK) {
961 cr1 |= STM32F7_I2C_CR1_PECEN;
962 if (!f7_msg->read_write) {
963 cr2 |= STM32F7_I2C_CR2_PECBYTE;
967 cr1 &= ~STM32F7_I2C_CR1_PECEN;
968 cr2 &= ~STM32F7_I2C_CR2_PECBYTE;
971 /* Set number of bytes to be transferred */
972 cr2 &= ~(STM32F7_I2C_CR2_NBYTES_MASK | STM32F7_I2C_CR2_RELOAD);
973 cr2 |= STM32F7_I2C_CR2_NBYTES(f7_msg->count);
975 /* Enable NACK, STOP, error and transfer complete interrupts */
976 cr1 |= STM32F7_I2C_CR1_ERRIE | STM32F7_I2C_CR1_TCIE |
977 STM32F7_I2C_CR1_STOPIE | STM32F7_I2C_CR1_NACKIE;
979 /* Clear DMA req and TX/RX interrupt */
980 cr1 &= ~(STM32F7_I2C_CR1_RXIE | STM32F7_I2C_CR1_TXIE |
981 STM32F7_I2C_CR1_RXDMAEN | STM32F7_I2C_CR1_TXDMAEN);
983 /* Configure DMA or enable RX/TX interrupt */
984 i2c_dev->use_dma = false;
985 if (i2c_dev->dma && f7_msg->count >= STM32F7_I2C_DMA_LEN_MIN) {
986 ret = stm32_i2c_prep_dma_xfer(i2c_dev->dev, i2c_dev->dma,
987 cr2 & STM32F7_I2C_CR2_RD_WRN,
988 f7_msg->count, f7_msg->buf,
989 stm32f7_i2c_dma_callback,
992 i2c_dev->use_dma = true;
994 dev_warn(i2c_dev->dev, "can't use DMA\n");
997 if (!i2c_dev->use_dma) {
998 if (cr2 & STM32F7_I2C_CR2_RD_WRN)
999 cr1 |= STM32F7_I2C_CR1_RXIE;
1001 cr1 |= STM32F7_I2C_CR1_TXIE;
1003 if (cr2 & STM32F7_I2C_CR2_RD_WRN)
1004 cr1 |= STM32F7_I2C_CR1_RXDMAEN;
1006 cr1 |= STM32F7_I2C_CR1_TXDMAEN;
1010 cr2 |= STM32F7_I2C_CR2_START;
1012 i2c_dev->master_mode = true;
1014 /* Write configurations registers */
1015 writel_relaxed(cr1, base + STM32F7_I2C_CR1);
1016 writel_relaxed(cr2, base + STM32F7_I2C_CR2);
1021 static void stm32f7_i2c_smbus_rep_start(struct stm32f7_i2c_dev *i2c_dev)
1023 struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
1024 void __iomem *base = i2c_dev->base;
1028 cr2 = readl_relaxed(base + STM32F7_I2C_CR2);
1029 cr1 = readl_relaxed(base + STM32F7_I2C_CR1);
1031 /* Set transfer direction */
1032 cr2 |= STM32F7_I2C_CR2_RD_WRN;
1034 switch (f7_msg->size) {
1035 case I2C_SMBUS_BYTE_DATA:
1038 case I2C_SMBUS_WORD_DATA:
1039 case I2C_SMBUS_PROC_CALL:
1042 case I2C_SMBUS_BLOCK_DATA:
1043 case I2C_SMBUS_BLOCK_PROC_CALL:
1045 cr2 |= STM32F7_I2C_CR2_RELOAD;
1049 f7_msg->buf = f7_msg->smbus_buf;
1050 f7_msg->stop = true;
1052 /* Add one byte for PEC if needed */
1053 if (cr1 & STM32F7_I2C_CR1_PECEN) {
1054 cr2 |= STM32F7_I2C_CR2_PECBYTE;
1058 /* Set number of bytes to be transferred */
1059 cr2 &= ~(STM32F7_I2C_CR2_NBYTES_MASK);
1060 cr2 |= STM32F7_I2C_CR2_NBYTES(f7_msg->count);
1063 * Configure RX/TX interrupt:
1065 cr1 &= ~(STM32F7_I2C_CR1_RXIE | STM32F7_I2C_CR1_TXIE);
1066 cr1 |= STM32F7_I2C_CR1_RXIE;
1069 * Configure DMA or enable RX/TX interrupt:
1070 * For I2C_SMBUS_BLOCK_DATA and I2C_SMBUS_BLOCK_PROC_CALL we don't use
1071 * dma as we don't know in advance how many data will be received
1073 cr1 &= ~(STM32F7_I2C_CR1_RXIE | STM32F7_I2C_CR1_TXIE |
1074 STM32F7_I2C_CR1_RXDMAEN | STM32F7_I2C_CR1_TXDMAEN);
1076 i2c_dev->use_dma = false;
1077 if (i2c_dev->dma && f7_msg->count >= STM32F7_I2C_DMA_LEN_MIN &&
1078 f7_msg->size != I2C_SMBUS_BLOCK_DATA &&
1079 f7_msg->size != I2C_SMBUS_BLOCK_PROC_CALL) {
1080 ret = stm32_i2c_prep_dma_xfer(i2c_dev->dev, i2c_dev->dma,
1081 cr2 & STM32F7_I2C_CR2_RD_WRN,
1082 f7_msg->count, f7_msg->buf,
1083 stm32f7_i2c_dma_callback,
1087 i2c_dev->use_dma = true;
1089 dev_warn(i2c_dev->dev, "can't use DMA\n");
1092 if (!i2c_dev->use_dma)
1093 cr1 |= STM32F7_I2C_CR1_RXIE;
1095 cr1 |= STM32F7_I2C_CR1_RXDMAEN;
1097 /* Configure Repeated Start */
1098 cr2 |= STM32F7_I2C_CR2_START;
1100 /* Write configurations registers */
1101 writel_relaxed(cr1, base + STM32F7_I2C_CR1);
1102 writel_relaxed(cr2, base + STM32F7_I2C_CR2);
1105 static int stm32f7_i2c_smbus_check_pec(struct stm32f7_i2c_dev *i2c_dev)
1107 struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
1108 u8 count, internal_pec, received_pec;
1110 internal_pec = readl_relaxed(i2c_dev->base + STM32F7_I2C_PECR);
1112 switch (f7_msg->size) {
1113 case I2C_SMBUS_BYTE:
1114 case I2C_SMBUS_BYTE_DATA:
1115 received_pec = f7_msg->smbus_buf[1];
1117 case I2C_SMBUS_WORD_DATA:
1118 case I2C_SMBUS_PROC_CALL:
1119 received_pec = f7_msg->smbus_buf[2];
1121 case I2C_SMBUS_BLOCK_DATA:
1122 case I2C_SMBUS_BLOCK_PROC_CALL:
1123 count = f7_msg->smbus_buf[0];
1124 received_pec = f7_msg->smbus_buf[count];
1127 dev_err(i2c_dev->dev, "Unsupported smbus protocol for PEC\n");
1131 if (internal_pec != received_pec) {
1132 dev_err(i2c_dev->dev, "Bad PEC 0x%02x vs. 0x%02x\n",
1133 internal_pec, received_pec);
1140 static bool stm32f7_i2c_is_addr_match(struct i2c_client *slave, u32 addcode)
1147 if (slave->flags & I2C_CLIENT_TEN) {
1149 * For 10-bit addr, addcode = 11110XY with
1150 * X = Bit 9 of slave address
1151 * Y = Bit 8 of slave address
1153 addr = slave->addr >> 8;
1155 if (addr == addcode)
1158 addr = slave->addr & 0x7f;
1159 if (addr == addcode)
1166 static void stm32f7_i2c_slave_start(struct stm32f7_i2c_dev *i2c_dev)
1168 struct i2c_client *slave = i2c_dev->slave_running;
1169 void __iomem *base = i2c_dev->base;
1173 if (i2c_dev->slave_dir) {
1174 /* Notify i2c slave that new read transfer is starting */
1175 i2c_slave_event(slave, I2C_SLAVE_READ_REQUESTED, &value);
1178 * Disable slave TX config in case of I2C combined message
1179 * (I2C Write followed by I2C Read)
1181 mask = STM32F7_I2C_CR2_RELOAD;
1182 stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR2, mask);
1183 mask = STM32F7_I2C_CR1_SBC | STM32F7_I2C_CR1_RXIE |
1184 STM32F7_I2C_CR1_TCIE;
1185 stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR1, mask);
1187 /* Enable TX empty, STOP, NACK interrupts */
1188 mask = STM32F7_I2C_CR1_STOPIE | STM32F7_I2C_CR1_NACKIE |
1189 STM32F7_I2C_CR1_TXIE;
1190 stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, mask);
1192 /* Write 1st data byte */
1193 writel_relaxed(value, base + STM32F7_I2C_TXDR);
1195 /* Notify i2c slave that new write transfer is starting */
1196 i2c_slave_event(slave, I2C_SLAVE_WRITE_REQUESTED, &value);
1198 /* Set reload mode to be able to ACK/NACK each received byte */
1199 mask = STM32F7_I2C_CR2_RELOAD;
1200 stm32f7_i2c_set_bits(base + STM32F7_I2C_CR2, mask);
1203 * Set STOP, NACK, RX empty and transfer complete interrupts.*
1204 * Set Slave Byte Control to be able to ACK/NACK each data
1207 mask = STM32F7_I2C_CR1_STOPIE | STM32F7_I2C_CR1_NACKIE |
1208 STM32F7_I2C_CR1_SBC | STM32F7_I2C_CR1_RXIE |
1209 STM32F7_I2C_CR1_TCIE;
1210 stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, mask);
1214 static void stm32f7_i2c_slave_addr(struct stm32f7_i2c_dev *i2c_dev)
1216 void __iomem *base = i2c_dev->base;
1217 u32 isr, addcode, dir, mask;
1220 isr = readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR);
1221 addcode = STM32F7_I2C_ISR_ADDCODE_GET(isr);
1222 dir = isr & STM32F7_I2C_ISR_DIR;
1224 for (i = 0; i < STM32F7_I2C_MAX_SLAVE; i++) {
1225 if (stm32f7_i2c_is_addr_match(i2c_dev->slave[i], addcode)) {
1226 i2c_dev->slave_running = i2c_dev->slave[i];
1227 i2c_dev->slave_dir = dir;
1229 /* Start I2C slave processing */
1230 stm32f7_i2c_slave_start(i2c_dev);
1232 /* Clear ADDR flag */
1233 mask = STM32F7_I2C_ICR_ADDRCF;
1234 writel_relaxed(mask, base + STM32F7_I2C_ICR);
1240 static int stm32f7_i2c_get_slave_id(struct stm32f7_i2c_dev *i2c_dev,
1241 struct i2c_client *slave, int *id)
1245 for (i = 0; i < STM32F7_I2C_MAX_SLAVE; i++) {
1246 if (i2c_dev->slave[i] == slave) {
1252 dev_err(i2c_dev->dev, "Slave 0x%x not registered\n", slave->addr);
1257 static int stm32f7_i2c_get_free_slave_id(struct stm32f7_i2c_dev *i2c_dev,
1258 struct i2c_client *slave, int *id)
1260 struct device *dev = i2c_dev->dev;
1264 * slave[0] supports 7-bit and 10-bit slave address
1265 * slave[1] supports 7-bit slave address only
1267 for (i = STM32F7_I2C_MAX_SLAVE - 1; i >= 0; i--) {
1268 if (i == 1 && (slave->flags & I2C_CLIENT_TEN))
1270 if (!i2c_dev->slave[i]) {
1276 dev_err(dev, "Slave 0x%x could not be registered\n", slave->addr);
1281 static bool stm32f7_i2c_is_slave_registered(struct stm32f7_i2c_dev *i2c_dev)
1285 for (i = 0; i < STM32F7_I2C_MAX_SLAVE; i++) {
1286 if (i2c_dev->slave[i])
1293 static bool stm32f7_i2c_is_slave_busy(struct stm32f7_i2c_dev *i2c_dev)
1298 for (i = 0; i < STM32F7_I2C_MAX_SLAVE; i++) {
1299 if (i2c_dev->slave[i])
1306 static irqreturn_t stm32f7_i2c_slave_isr_event(struct stm32f7_i2c_dev *i2c_dev)
1308 void __iomem *base = i2c_dev->base;
1309 u32 cr2, status, mask;
1313 status = readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR);
1315 /* Slave transmitter mode */
1316 if (status & STM32F7_I2C_ISR_TXIS) {
1317 i2c_slave_event(i2c_dev->slave_running,
1318 I2C_SLAVE_READ_PROCESSED,
1321 /* Write data byte */
1322 writel_relaxed(val, base + STM32F7_I2C_TXDR);
1325 /* Transfer Complete Reload for Slave receiver mode */
1326 if (status & STM32F7_I2C_ISR_TCR || status & STM32F7_I2C_ISR_RXNE) {
1328 * Read data byte then set NBYTES to receive next byte or NACK
1329 * the current received byte
1331 val = readb_relaxed(i2c_dev->base + STM32F7_I2C_RXDR);
1332 ret = i2c_slave_event(i2c_dev->slave_running,
1333 I2C_SLAVE_WRITE_RECEIVED,
1336 cr2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_CR2);
1337 cr2 |= STM32F7_I2C_CR2_NBYTES(1);
1338 writel_relaxed(cr2, i2c_dev->base + STM32F7_I2C_CR2);
1340 mask = STM32F7_I2C_CR2_NACK;
1341 stm32f7_i2c_set_bits(base + STM32F7_I2C_CR2, mask);
1346 if (status & STM32F7_I2C_ISR_NACKF) {
1347 dev_dbg(i2c_dev->dev, "<%s>: Receive NACK\n", __func__);
1348 writel_relaxed(STM32F7_I2C_ICR_NACKCF, base + STM32F7_I2C_ICR);
1352 if (status & STM32F7_I2C_ISR_STOPF) {
1353 /* Disable interrupts */
1354 stm32f7_i2c_disable_irq(i2c_dev, STM32F7_I2C_XFER_IRQ_MASK);
1356 if (i2c_dev->slave_dir) {
1358 * Flush TX buffer in order to not used the byte in
1359 * TXDR for the next transfer
1361 mask = STM32F7_I2C_ISR_TXE;
1362 stm32f7_i2c_set_bits(base + STM32F7_I2C_ISR, mask);
1365 /* Clear STOP flag */
1366 writel_relaxed(STM32F7_I2C_ICR_STOPCF, base + STM32F7_I2C_ICR);
1368 /* Notify i2c slave that a STOP flag has been detected */
1369 i2c_slave_event(i2c_dev->slave_running, I2C_SLAVE_STOP, &val);
1371 i2c_dev->slave_running = NULL;
1374 /* Address match received */
1375 if (status & STM32F7_I2C_ISR_ADDR)
1376 stm32f7_i2c_slave_addr(i2c_dev);
1381 static irqreturn_t stm32f7_i2c_isr_event(int irq, void *data)
1383 struct stm32f7_i2c_dev *i2c_dev = data;
1384 struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
1385 struct stm32_i2c_dma *dma = i2c_dev->dma;
1386 void __iomem *base = i2c_dev->base;
1388 int ret = IRQ_HANDLED;
1390 /* Check if the interrupt if for a slave device */
1391 if (!i2c_dev->master_mode) {
1392 ret = stm32f7_i2c_slave_isr_event(i2c_dev);
1396 status = readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR);
1399 if (status & STM32F7_I2C_ISR_TXIS)
1400 stm32f7_i2c_write_tx_data(i2c_dev);
1403 if (status & STM32F7_I2C_ISR_RXNE)
1404 stm32f7_i2c_read_rx_data(i2c_dev);
1407 if (status & STM32F7_I2C_ISR_NACKF) {
1408 dev_dbg(i2c_dev->dev, "<%s>: Receive NACK\n", __func__);
1409 writel_relaxed(STM32F7_I2C_ICR_NACKCF, base + STM32F7_I2C_ICR);
1410 if (i2c_dev->use_dma) {
1411 stm32f7_i2c_disable_dma_req(i2c_dev);
1412 dmaengine_terminate_all(dma->chan_using);
1414 f7_msg->result = -ENXIO;
1417 /* STOP detection flag */
1418 if (status & STM32F7_I2C_ISR_STOPF) {
1419 /* Disable interrupts */
1420 if (stm32f7_i2c_is_slave_registered(i2c_dev))
1421 mask = STM32F7_I2C_XFER_IRQ_MASK;
1423 mask = STM32F7_I2C_ALL_IRQ_MASK;
1424 stm32f7_i2c_disable_irq(i2c_dev, mask);
1426 /* Clear STOP flag */
1427 writel_relaxed(STM32F7_I2C_ICR_STOPCF, base + STM32F7_I2C_ICR);
1429 if (i2c_dev->use_dma && !f7_msg->result) {
1430 ret = IRQ_WAKE_THREAD;
1432 i2c_dev->master_mode = false;
1433 complete(&i2c_dev->complete);
1437 /* Transfer complete */
1438 if (status & STM32F7_I2C_ISR_TC) {
1440 mask = STM32F7_I2C_CR2_STOP;
1441 stm32f7_i2c_set_bits(base + STM32F7_I2C_CR2, mask);
1442 } else if (i2c_dev->use_dma && !f7_msg->result) {
1443 ret = IRQ_WAKE_THREAD;
1444 } else if (f7_msg->smbus) {
1445 stm32f7_i2c_smbus_rep_start(i2c_dev);
1449 stm32f7_i2c_xfer_msg(i2c_dev, i2c_dev->msg);
1453 if (status & STM32F7_I2C_ISR_TCR) {
1455 stm32f7_i2c_smbus_reload(i2c_dev);
1457 stm32f7_i2c_reload(i2c_dev);
1463 static irqreturn_t stm32f7_i2c_isr_event_thread(int irq, void *data)
1465 struct stm32f7_i2c_dev *i2c_dev = data;
1466 struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
1467 struct stm32_i2c_dma *dma = i2c_dev->dma;
1472 * Wait for dma transfer completion before sending next message or
1473 * notity the end of xfer to the client
1475 ret = wait_for_completion_timeout(&i2c_dev->dma->dma_complete, HZ);
1477 dev_dbg(i2c_dev->dev, "<%s>: Timed out\n", __func__);
1478 stm32f7_i2c_disable_dma_req(i2c_dev);
1479 dmaengine_terminate_all(dma->chan_using);
1480 f7_msg->result = -ETIMEDOUT;
1483 status = readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR);
1485 if (status & STM32F7_I2C_ISR_TC) {
1486 if (f7_msg->smbus) {
1487 stm32f7_i2c_smbus_rep_start(i2c_dev);
1491 stm32f7_i2c_xfer_msg(i2c_dev, i2c_dev->msg);
1494 i2c_dev->master_mode = false;
1495 complete(&i2c_dev->complete);
1501 static irqreturn_t stm32f7_i2c_isr_error(int irq, void *data)
1503 struct stm32f7_i2c_dev *i2c_dev = data;
1504 struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
1505 void __iomem *base = i2c_dev->base;
1506 struct device *dev = i2c_dev->dev;
1507 struct stm32_i2c_dma *dma = i2c_dev->dma;
1510 status = readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR);
1513 if (status & STM32F7_I2C_ISR_BERR) {
1514 dev_err(dev, "<%s>: Bus error\n", __func__);
1515 writel_relaxed(STM32F7_I2C_ICR_BERRCF, base + STM32F7_I2C_ICR);
1516 stm32f7_i2c_release_bus(&i2c_dev->adap);
1517 f7_msg->result = -EIO;
1520 /* Arbitration loss */
1521 if (status & STM32F7_I2C_ISR_ARLO) {
1522 dev_dbg(dev, "<%s>: Arbitration loss\n", __func__);
1523 writel_relaxed(STM32F7_I2C_ICR_ARLOCF, base + STM32F7_I2C_ICR);
1524 f7_msg->result = -EAGAIN;
1527 if (status & STM32F7_I2C_ISR_PECERR) {
1528 dev_err(dev, "<%s>: PEC error in reception\n", __func__);
1529 writel_relaxed(STM32F7_I2C_ICR_PECCF, base + STM32F7_I2C_ICR);
1530 f7_msg->result = -EINVAL;
1533 if (!i2c_dev->slave_running) {
1535 /* Disable interrupts */
1536 if (stm32f7_i2c_is_slave_registered(i2c_dev))
1537 mask = STM32F7_I2C_XFER_IRQ_MASK;
1539 mask = STM32F7_I2C_ALL_IRQ_MASK;
1540 stm32f7_i2c_disable_irq(i2c_dev, mask);
1544 if (i2c_dev->use_dma) {
1545 stm32f7_i2c_disable_dma_req(i2c_dev);
1546 dmaengine_terminate_all(dma->chan_using);
1549 i2c_dev->master_mode = false;
1550 complete(&i2c_dev->complete);
1555 static int stm32f7_i2c_xfer(struct i2c_adapter *i2c_adap,
1556 struct i2c_msg msgs[], int num)
1558 struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(i2c_adap);
1559 struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
1560 struct stm32_i2c_dma *dma = i2c_dev->dma;
1561 unsigned long time_left;
1564 i2c_dev->msg = msgs;
1565 i2c_dev->msg_num = num;
1566 i2c_dev->msg_id = 0;
1567 f7_msg->smbus = false;
1569 ret = clk_enable(i2c_dev->clk);
1571 dev_err(i2c_dev->dev, "Failed to enable clock\n");
1575 ret = stm32f7_i2c_wait_free_bus(i2c_dev);
1579 stm32f7_i2c_xfer_msg(i2c_dev, msgs);
1581 time_left = wait_for_completion_timeout(&i2c_dev->complete,
1582 i2c_dev->adap.timeout);
1583 ret = f7_msg->result;
1586 dev_dbg(i2c_dev->dev, "Access to slave 0x%x timed out\n",
1587 i2c_dev->msg->addr);
1588 if (i2c_dev->use_dma)
1589 dmaengine_terminate_all(dma->chan_using);
1590 stm32f7_i2c_wait_free_bus(i2c_dev);
1595 clk_disable(i2c_dev->clk);
1597 return (ret < 0) ? ret : num;
1600 static int stm32f7_i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
1601 unsigned short flags, char read_write,
1602 u8 command, int size,
1603 union i2c_smbus_data *data)
1605 struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(adapter);
1606 struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
1607 struct stm32_i2c_dma *dma = i2c_dev->dma;
1608 struct device *dev = i2c_dev->dev;
1609 unsigned long timeout;
1612 f7_msg->addr = addr;
1613 f7_msg->size = size;
1614 f7_msg->read_write = read_write;
1615 f7_msg->smbus = true;
1617 ret = clk_enable(i2c_dev->clk);
1619 dev_err(i2c_dev->dev, "Failed to enable clock\n");
1623 ret = stm32f7_i2c_wait_free_bus(i2c_dev);
1627 ret = stm32f7_i2c_smbus_xfer_msg(i2c_dev, flags, command, data);
1631 timeout = wait_for_completion_timeout(&i2c_dev->complete,
1632 i2c_dev->adap.timeout);
1633 ret = f7_msg->result;
1638 dev_dbg(dev, "Access to slave 0x%x timed out\n", f7_msg->addr);
1639 if (i2c_dev->use_dma)
1640 dmaengine_terminate_all(dma->chan_using);
1641 stm32f7_i2c_wait_free_bus(i2c_dev);
1647 if ((flags & I2C_CLIENT_PEC) && size != I2C_SMBUS_QUICK && read_write) {
1648 ret = stm32f7_i2c_smbus_check_pec(i2c_dev);
1653 if (read_write && size != I2C_SMBUS_QUICK) {
1655 case I2C_SMBUS_BYTE:
1656 case I2C_SMBUS_BYTE_DATA:
1657 data->byte = f7_msg->smbus_buf[0];
1659 case I2C_SMBUS_WORD_DATA:
1660 case I2C_SMBUS_PROC_CALL:
1661 data->word = f7_msg->smbus_buf[0] |
1662 (f7_msg->smbus_buf[1] << 8);
1664 case I2C_SMBUS_BLOCK_DATA:
1665 case I2C_SMBUS_BLOCK_PROC_CALL:
1666 for (i = 0; i <= f7_msg->smbus_buf[0]; i++)
1667 data->block[i] = f7_msg->smbus_buf[i];
1670 dev_err(dev, "Unsupported smbus transaction\n");
1676 clk_disable(i2c_dev->clk);
1680 static int stm32f7_i2c_reg_slave(struct i2c_client *slave)
1682 struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(slave->adapter);
1683 void __iomem *base = i2c_dev->base;
1684 struct device *dev = i2c_dev->dev;
1685 u32 oar1, oar2, mask;
1688 if (slave->flags & I2C_CLIENT_PEC) {
1689 dev_err(dev, "SMBus PEC not supported in slave mode\n");
1693 if (stm32f7_i2c_is_slave_busy(i2c_dev)) {
1694 dev_err(dev, "Too much slave registered\n");
1698 ret = stm32f7_i2c_get_free_slave_id(i2c_dev, slave, &id);
1702 if (!(stm32f7_i2c_is_slave_registered(i2c_dev))) {
1703 ret = clk_enable(i2c_dev->clk);
1705 dev_err(dev, "Failed to enable clock\n");
1711 /* Configure Own Address 1 */
1712 oar1 = readl_relaxed(i2c_dev->base + STM32F7_I2C_OAR1);
1713 oar1 &= ~STM32F7_I2C_OAR1_MASK;
1714 if (slave->flags & I2C_CLIENT_TEN) {
1715 oar1 |= STM32F7_I2C_OAR1_OA1_10(slave->addr);
1716 oar1 |= STM32F7_I2C_OAR1_OA1MODE;
1718 oar1 |= STM32F7_I2C_OAR1_OA1_7(slave->addr);
1720 oar1 |= STM32F7_I2C_OAR1_OA1EN;
1721 i2c_dev->slave[id] = slave;
1722 writel_relaxed(oar1, i2c_dev->base + STM32F7_I2C_OAR1);
1723 } else if (id == 1) {
1724 /* Configure Own Address 2 */
1725 oar2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_OAR2);
1726 oar2 &= ~STM32F7_I2C_OAR2_MASK;
1727 if (slave->flags & I2C_CLIENT_TEN) {
1732 oar2 |= STM32F7_I2C_OAR2_OA2_7(slave->addr);
1733 oar2 |= STM32F7_I2C_OAR2_OA2EN;
1734 i2c_dev->slave[id] = slave;
1735 writel_relaxed(oar2, i2c_dev->base + STM32F7_I2C_OAR2);
1742 stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR2, STM32F7_I2C_CR2_NACK);
1744 /* Enable Address match interrupt, error interrupt and enable I2C */
1745 mask = STM32F7_I2C_CR1_ADDRIE | STM32F7_I2C_CR1_ERRIE |
1747 stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, mask);
1752 if (!(stm32f7_i2c_is_slave_registered(i2c_dev)))
1753 clk_disable(i2c_dev->clk);
1758 static int stm32f7_i2c_unreg_slave(struct i2c_client *slave)
1760 struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(slave->adapter);
1761 void __iomem *base = i2c_dev->base;
1765 ret = stm32f7_i2c_get_slave_id(i2c_dev, slave, &id);
1769 WARN_ON(!i2c_dev->slave[id]);
1772 mask = STM32F7_I2C_OAR1_OA1EN;
1773 stm32f7_i2c_clr_bits(base + STM32F7_I2C_OAR1, mask);
1775 mask = STM32F7_I2C_OAR2_OA2EN;
1776 stm32f7_i2c_clr_bits(base + STM32F7_I2C_OAR2, mask);
1779 i2c_dev->slave[id] = NULL;
1781 if (!(stm32f7_i2c_is_slave_registered(i2c_dev))) {
1782 stm32f7_i2c_disable_irq(i2c_dev, STM32F7_I2C_ALL_IRQ_MASK);
1783 clk_disable(i2c_dev->clk);
1789 static u32 stm32f7_i2c_func(struct i2c_adapter *adap)
1791 return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | I2C_FUNC_SLAVE |
1792 I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
1793 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
1794 I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
1795 I2C_FUNC_SMBUS_PROC_CALL | I2C_FUNC_SMBUS_PEC;
1798 static struct i2c_algorithm stm32f7_i2c_algo = {
1799 .master_xfer = stm32f7_i2c_xfer,
1800 .smbus_xfer = stm32f7_i2c_smbus_xfer,
1801 .functionality = stm32f7_i2c_func,
1802 .reg_slave = stm32f7_i2c_reg_slave,
1803 .unreg_slave = stm32f7_i2c_unreg_slave,
1806 static int stm32f7_i2c_probe(struct platform_device *pdev)
1808 struct stm32f7_i2c_dev *i2c_dev;
1809 const struct stm32f7_i2c_setup *setup;
1810 struct resource *res;
1811 u32 clk_rate, rise_time, fall_time;
1812 struct i2c_adapter *adap;
1813 struct reset_control *rst;
1814 dma_addr_t phy_addr;
1815 int irq_error, irq_event, ret;
1817 i2c_dev = devm_kzalloc(&pdev->dev, sizeof(*i2c_dev), GFP_KERNEL);
1821 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1822 i2c_dev->base = devm_ioremap_resource(&pdev->dev, res);
1823 if (IS_ERR(i2c_dev->base))
1824 return PTR_ERR(i2c_dev->base);
1825 phy_addr = (dma_addr_t)res->start;
1827 irq_event = platform_get_irq(pdev, 0);
1828 if (irq_event <= 0) {
1829 if (irq_event != -EPROBE_DEFER)
1830 dev_err(&pdev->dev, "Failed to get IRQ event: %d\n",
1832 return irq_event ? : -ENOENT;
1835 irq_error = platform_get_irq(pdev, 1);
1836 if (irq_error <= 0) {
1837 if (irq_error != -EPROBE_DEFER)
1838 dev_err(&pdev->dev, "Failed to get IRQ error: %d\n",
1840 return irq_error ? : -ENOENT;
1843 i2c_dev->clk = devm_clk_get(&pdev->dev, NULL);
1844 if (IS_ERR(i2c_dev->clk)) {
1845 dev_err(&pdev->dev, "Error: Missing controller clock\n");
1846 return PTR_ERR(i2c_dev->clk);
1848 ret = clk_prepare_enable(i2c_dev->clk);
1850 dev_err(&pdev->dev, "Failed to prepare_enable clock\n");
1854 i2c_dev->speed = STM32_I2C_SPEED_STANDARD;
1855 ret = device_property_read_u32(&pdev->dev, "clock-frequency",
1857 if (!ret && clk_rate >= 1000000)
1858 i2c_dev->speed = STM32_I2C_SPEED_FAST_PLUS;
1859 else if (!ret && clk_rate >= 400000)
1860 i2c_dev->speed = STM32_I2C_SPEED_FAST;
1861 else if (!ret && clk_rate >= 100000)
1862 i2c_dev->speed = STM32_I2C_SPEED_STANDARD;
1864 rst = devm_reset_control_get(&pdev->dev, NULL);
1866 dev_err(&pdev->dev, "Error: Missing controller reset\n");
1870 reset_control_assert(rst);
1872 reset_control_deassert(rst);
1874 i2c_dev->dev = &pdev->dev;
1876 ret = devm_request_threaded_irq(&pdev->dev, irq_event,
1877 stm32f7_i2c_isr_event,
1878 stm32f7_i2c_isr_event_thread,
1880 pdev->name, i2c_dev);
1882 dev_err(&pdev->dev, "Failed to request irq event %i\n",
1887 ret = devm_request_irq(&pdev->dev, irq_error, stm32f7_i2c_isr_error, 0,
1888 pdev->name, i2c_dev);
1890 dev_err(&pdev->dev, "Failed to request irq error %i\n",
1895 setup = of_device_get_match_data(&pdev->dev);
1897 dev_err(&pdev->dev, "Can't get device data\n");
1901 i2c_dev->setup = *setup;
1903 ret = device_property_read_u32(i2c_dev->dev, "i2c-scl-rising-time-ns",
1906 i2c_dev->setup.rise_time = rise_time;
1908 ret = device_property_read_u32(i2c_dev->dev, "i2c-scl-falling-time-ns",
1911 i2c_dev->setup.fall_time = fall_time;
1913 ret = stm32f7_i2c_setup_timing(i2c_dev, &i2c_dev->setup);
1917 stm32f7_i2c_hw_config(i2c_dev);
1919 adap = &i2c_dev->adap;
1920 i2c_set_adapdata(adap, i2c_dev);
1921 snprintf(adap->name, sizeof(adap->name), "STM32F7 I2C(%pa)",
1923 adap->owner = THIS_MODULE;
1924 adap->timeout = 2 * HZ;
1926 adap->algo = &stm32f7_i2c_algo;
1927 adap->dev.parent = &pdev->dev;
1928 adap->dev.of_node = pdev->dev.of_node;
1930 init_completion(&i2c_dev->complete);
1932 /* Init DMA config if supported */
1933 i2c_dev->dma = stm32_i2c_dma_request(i2c_dev->dev, phy_addr,
1936 if (PTR_ERR(i2c_dev->dma) == -ENODEV)
1937 i2c_dev->dma = NULL;
1938 else if (IS_ERR(i2c_dev->dma)) {
1939 ret = PTR_ERR(i2c_dev->dma);
1940 if (ret != -EPROBE_DEFER)
1942 "Failed to request dma error %i\n", ret);
1946 ret = i2c_add_adapter(adap);
1950 platform_set_drvdata(pdev, i2c_dev);
1952 clk_disable(i2c_dev->clk);
1954 dev_info(i2c_dev->dev, "STM32F7 I2C-%d bus adapter\n", adap->nr);
1959 clk_disable_unprepare(i2c_dev->clk);
1964 static int stm32f7_i2c_remove(struct platform_device *pdev)
1966 struct stm32f7_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
1969 stm32_i2c_dma_free(i2c_dev->dma);
1970 i2c_dev->dma = NULL;
1973 i2c_del_adapter(&i2c_dev->adap);
1975 clk_unprepare(i2c_dev->clk);
1980 static const struct of_device_id stm32f7_i2c_match[] = {
1981 { .compatible = "st,stm32f7-i2c", .data = &stm32f7_setup},
1984 MODULE_DEVICE_TABLE(of, stm32f7_i2c_match);
1986 static struct platform_driver stm32f7_i2c_driver = {
1988 .name = "stm32f7-i2c",
1989 .of_match_table = stm32f7_i2c_match,
1991 .probe = stm32f7_i2c_probe,
1992 .remove = stm32f7_i2c_remove,
1995 module_platform_driver(stm32f7_i2c_driver);
1997 MODULE_AUTHOR("M'boumba Cedric Madianga <cedric.madianga@gmail.com>");
1998 MODULE_DESCRIPTION("STMicroelectronics STM32F7 I2C driver");
1999 MODULE_LICENSE("GPL v2");