3 * Copyright (c) 2002-2007 Xilinx Inc.
4 * Copyright (c) 2009-2010 Intel Corporation
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
16 * This code was implemented by Mocean Laboratories AB when porting linux
17 * to the automotive development board Russellville. The copyright holder
18 * as seen in the header is Intel corporation.
19 * Mocean Laboratories forked off the GNU/Linux platform work into a
20 * separate company called Pelagicore AB, which committed the code to the
27 #include <linux/kernel.h>
28 #include <linux/module.h>
29 #include <linux/errno.h>
30 #include <linux/err.h>
31 #include <linux/delay.h>
32 #include <linux/platform_device.h>
33 #include <linux/i2c.h>
34 #include <linux/interrupt.h>
35 #include <linux/wait.h>
36 #include <linux/platform_data/i2c-xiic.h>
38 #include <linux/slab.h>
40 #include <linux/clk.h>
41 #include <linux/pm_runtime.h>
43 #define DRIVER_NAME "xiic-i2c"
45 enum xilinx_i2c_state {
57 * struct xiic_i2c - Internal representation of the XIIC I2C bus
58 * @base: Memory base of the HW registers
59 * @wait: Wait queue for callers
60 * @adap: Kernel adapter representation
61 * @tx_msg: Messages from above to be sent
62 * @lock: Mutual exclusion
63 * @tx_pos: Current pos in TX message
64 * @nmsgs: Number of messages in tx_msg
66 * @rx_msg: Current RX message
67 * @rx_pos: Position within current RX message
68 * @endianness: big/little-endian byte order
73 wait_queue_head_t wait;
74 struct i2c_adapter adap;
75 struct i2c_msg *tx_msg;
79 enum xilinx_i2c_state state;
80 struct i2c_msg *rx_msg;
82 enum xiic_endian endianness;
87 #define XIIC_MSB_OFFSET 0
88 #define XIIC_REG_OFFSET (0x100+XIIC_MSB_OFFSET)
91 * Register offsets in bytes from RegisterBase. Three is added to the
92 * base offset to access LSB (IBM style) of the word
94 #define XIIC_CR_REG_OFFSET (0x00+XIIC_REG_OFFSET) /* Control Register */
95 #define XIIC_SR_REG_OFFSET (0x04+XIIC_REG_OFFSET) /* Status Register */
96 #define XIIC_DTR_REG_OFFSET (0x08+XIIC_REG_OFFSET) /* Data Tx Register */
97 #define XIIC_DRR_REG_OFFSET (0x0C+XIIC_REG_OFFSET) /* Data Rx Register */
98 #define XIIC_ADR_REG_OFFSET (0x10+XIIC_REG_OFFSET) /* Address Register */
99 #define XIIC_TFO_REG_OFFSET (0x14+XIIC_REG_OFFSET) /* Tx FIFO Occupancy */
100 #define XIIC_RFO_REG_OFFSET (0x18+XIIC_REG_OFFSET) /* Rx FIFO Occupancy */
101 #define XIIC_TBA_REG_OFFSET (0x1C+XIIC_REG_OFFSET) /* 10 Bit Address reg */
102 #define XIIC_RFD_REG_OFFSET (0x20+XIIC_REG_OFFSET) /* Rx FIFO Depth reg */
103 #define XIIC_GPO_REG_OFFSET (0x24+XIIC_REG_OFFSET) /* Output Register */
105 /* Control Register masks */
106 #define XIIC_CR_ENABLE_DEVICE_MASK 0x01 /* Device enable = 1 */
107 #define XIIC_CR_TX_FIFO_RESET_MASK 0x02 /* Transmit FIFO reset=1 */
108 #define XIIC_CR_MSMS_MASK 0x04 /* Master starts Txing=1 */
109 #define XIIC_CR_DIR_IS_TX_MASK 0x08 /* Dir of tx. Txing=1 */
110 #define XIIC_CR_NO_ACK_MASK 0x10 /* Tx Ack. NO ack = 1 */
111 #define XIIC_CR_REPEATED_START_MASK 0x20 /* Repeated start = 1 */
112 #define XIIC_CR_GENERAL_CALL_MASK 0x40 /* Gen Call enabled = 1 */
114 /* Status Register masks */
115 #define XIIC_SR_GEN_CALL_MASK 0x01 /* 1=a mstr issued a GC */
116 #define XIIC_SR_ADDR_AS_SLAVE_MASK 0x02 /* 1=when addr as slave */
117 #define XIIC_SR_BUS_BUSY_MASK 0x04 /* 1 = bus is busy */
118 #define XIIC_SR_MSTR_RDING_SLAVE_MASK 0x08 /* 1=Dir: mstr <-- slave */
119 #define XIIC_SR_TX_FIFO_FULL_MASK 0x10 /* 1 = Tx FIFO full */
120 #define XIIC_SR_RX_FIFO_FULL_MASK 0x20 /* 1 = Rx FIFO full */
121 #define XIIC_SR_RX_FIFO_EMPTY_MASK 0x40 /* 1 = Rx FIFO empty */
122 #define XIIC_SR_TX_FIFO_EMPTY_MASK 0x80 /* 1 = Tx FIFO empty */
124 /* Interrupt Status Register masks Interrupt occurs when... */
125 #define XIIC_INTR_ARB_LOST_MASK 0x01 /* 1 = arbitration lost */
126 #define XIIC_INTR_TX_ERROR_MASK 0x02 /* 1=Tx error/msg complete */
127 #define XIIC_INTR_TX_EMPTY_MASK 0x04 /* 1 = Tx FIFO/reg empty */
128 #define XIIC_INTR_RX_FULL_MASK 0x08 /* 1=Rx FIFO/reg=OCY level */
129 #define XIIC_INTR_BNB_MASK 0x10 /* 1 = Bus not busy */
130 #define XIIC_INTR_AAS_MASK 0x20 /* 1 = when addr as slave */
131 #define XIIC_INTR_NAAS_MASK 0x40 /* 1 = not addr as slave */
132 #define XIIC_INTR_TX_HALF_MASK 0x80 /* 1 = TX FIFO half empty */
134 /* The following constants specify the depth of the FIFOs */
135 #define IIC_RX_FIFO_DEPTH 16 /* Rx fifo capacity */
136 #define IIC_TX_FIFO_DEPTH 16 /* Tx fifo capacity */
138 /* The following constants specify groups of interrupts that are typically
139 * enabled or disables at the same time
141 #define XIIC_TX_INTERRUPTS \
142 (XIIC_INTR_TX_ERROR_MASK | XIIC_INTR_TX_EMPTY_MASK | XIIC_INTR_TX_HALF_MASK)
144 #define XIIC_TX_RX_INTERRUPTS (XIIC_INTR_RX_FULL_MASK | XIIC_TX_INTERRUPTS)
147 * Tx Fifo upper bit masks.
149 #define XIIC_TX_DYN_START_MASK 0x0100 /* 1 = Set dynamic start */
150 #define XIIC_TX_DYN_STOP_MASK 0x0200 /* 1 = Set dynamic stop */
153 * The following constants define the register offsets for the Interrupt
154 * registers. There are some holes in the memory map for reserved addresses
155 * to allow other registers to be added and still match the memory map of the
156 * interrupt controller registers
158 #define XIIC_DGIER_OFFSET 0x1C /* Device Global Interrupt Enable Register */
159 #define XIIC_IISR_OFFSET 0x20 /* Interrupt Status Register */
160 #define XIIC_IIER_OFFSET 0x28 /* Interrupt Enable Register */
161 #define XIIC_RESETR_OFFSET 0x40 /* Reset Register */
163 #define XIIC_RESET_MASK 0xAUL
165 #define XIIC_PM_TIMEOUT 1000 /* ms */
167 * The following constant is used for the device global interrupt enable
168 * register, to enable all interrupts for the device, this is the only bit
171 #define XIIC_GINTR_ENABLE_MASK 0x80000000UL
173 #define xiic_tx_space(i2c) ((i2c)->tx_msg->len - (i2c)->tx_pos)
174 #define xiic_rx_space(i2c) ((i2c)->rx_msg->len - (i2c)->rx_pos)
176 static void xiic_start_xfer(struct xiic_i2c *i2c);
177 static void __xiic_start_xfer(struct xiic_i2c *i2c);
180 * For the register read and write functions, a little-endian and big-endian
181 * version are necessary. Endianness is detected during the probe function.
182 * Only the least significant byte [doublet] of the register are ever
183 * accessed. This requires an offset of 3 [2] from the base address for
184 * big-endian systems.
187 static inline void xiic_setreg8(struct xiic_i2c *i2c, int reg, u8 value)
189 if (i2c->endianness == LITTLE)
190 iowrite8(value, i2c->base + reg);
192 iowrite8(value, i2c->base + reg + 3);
195 static inline u8 xiic_getreg8(struct xiic_i2c *i2c, int reg)
199 if (i2c->endianness == LITTLE)
200 ret = ioread8(i2c->base + reg);
202 ret = ioread8(i2c->base + reg + 3);
206 static inline void xiic_setreg16(struct xiic_i2c *i2c, int reg, u16 value)
208 if (i2c->endianness == LITTLE)
209 iowrite16(value, i2c->base + reg);
211 iowrite16be(value, i2c->base + reg + 2);
214 static inline void xiic_setreg32(struct xiic_i2c *i2c, int reg, int value)
216 if (i2c->endianness == LITTLE)
217 iowrite32(value, i2c->base + reg);
219 iowrite32be(value, i2c->base + reg);
222 static inline int xiic_getreg32(struct xiic_i2c *i2c, int reg)
226 if (i2c->endianness == LITTLE)
227 ret = ioread32(i2c->base + reg);
229 ret = ioread32be(i2c->base + reg);
233 static inline void xiic_irq_dis(struct xiic_i2c *i2c, u32 mask)
235 u32 ier = xiic_getreg32(i2c, XIIC_IIER_OFFSET);
236 xiic_setreg32(i2c, XIIC_IIER_OFFSET, ier & ~mask);
239 static inline void xiic_irq_en(struct xiic_i2c *i2c, u32 mask)
241 u32 ier = xiic_getreg32(i2c, XIIC_IIER_OFFSET);
242 xiic_setreg32(i2c, XIIC_IIER_OFFSET, ier | mask);
245 static inline void xiic_irq_clr(struct xiic_i2c *i2c, u32 mask)
247 u32 isr = xiic_getreg32(i2c, XIIC_IISR_OFFSET);
248 xiic_setreg32(i2c, XIIC_IISR_OFFSET, isr & mask);
251 static inline void xiic_irq_clr_en(struct xiic_i2c *i2c, u32 mask)
253 xiic_irq_clr(i2c, mask);
254 xiic_irq_en(i2c, mask);
257 static void xiic_clear_rx_fifo(struct xiic_i2c *i2c)
260 for (sr = xiic_getreg8(i2c, XIIC_SR_REG_OFFSET);
261 !(sr & XIIC_SR_RX_FIFO_EMPTY_MASK);
262 sr = xiic_getreg8(i2c, XIIC_SR_REG_OFFSET))
263 xiic_getreg8(i2c, XIIC_DRR_REG_OFFSET);
266 static void xiic_reinit(struct xiic_i2c *i2c)
268 xiic_setreg32(i2c, XIIC_RESETR_OFFSET, XIIC_RESET_MASK);
270 /* Set receive Fifo depth to maximum (zero based). */
271 xiic_setreg8(i2c, XIIC_RFD_REG_OFFSET, IIC_RX_FIFO_DEPTH - 1);
274 xiic_setreg8(i2c, XIIC_CR_REG_OFFSET, XIIC_CR_TX_FIFO_RESET_MASK);
276 /* Enable IIC Device, remove Tx Fifo reset & disable general call. */
277 xiic_setreg8(i2c, XIIC_CR_REG_OFFSET, XIIC_CR_ENABLE_DEVICE_MASK);
279 /* make sure RX fifo is empty */
280 xiic_clear_rx_fifo(i2c);
282 /* Enable interrupts */
283 xiic_setreg32(i2c, XIIC_DGIER_OFFSET, XIIC_GINTR_ENABLE_MASK);
285 xiic_irq_clr_en(i2c, XIIC_INTR_ARB_LOST_MASK);
288 static void xiic_deinit(struct xiic_i2c *i2c)
292 xiic_setreg32(i2c, XIIC_RESETR_OFFSET, XIIC_RESET_MASK);
294 /* Disable IIC Device. */
295 cr = xiic_getreg8(i2c, XIIC_CR_REG_OFFSET);
296 xiic_setreg8(i2c, XIIC_CR_REG_OFFSET, cr & ~XIIC_CR_ENABLE_DEVICE_MASK);
299 static void xiic_read_rx(struct xiic_i2c *i2c)
304 bytes_in_fifo = xiic_getreg8(i2c, XIIC_RFO_REG_OFFSET) + 1;
306 dev_dbg(i2c->adap.dev.parent,
307 "%s entry, bytes in fifo: %d, msg: %d, SR: 0x%x, CR: 0x%x\n",
308 __func__, bytes_in_fifo, xiic_rx_space(i2c),
309 xiic_getreg8(i2c, XIIC_SR_REG_OFFSET),
310 xiic_getreg8(i2c, XIIC_CR_REG_OFFSET));
312 if (bytes_in_fifo > xiic_rx_space(i2c))
313 bytes_in_fifo = xiic_rx_space(i2c);
315 for (i = 0; i < bytes_in_fifo; i++)
316 i2c->rx_msg->buf[i2c->rx_pos++] =
317 xiic_getreg8(i2c, XIIC_DRR_REG_OFFSET);
319 xiic_setreg8(i2c, XIIC_RFD_REG_OFFSET,
320 (xiic_rx_space(i2c) > IIC_RX_FIFO_DEPTH) ?
321 IIC_RX_FIFO_DEPTH - 1 : xiic_rx_space(i2c) - 1);
324 static int xiic_tx_fifo_space(struct xiic_i2c *i2c)
326 /* return the actual space left in the FIFO */
327 return IIC_TX_FIFO_DEPTH - xiic_getreg8(i2c, XIIC_TFO_REG_OFFSET) - 1;
330 static void xiic_fill_tx_fifo(struct xiic_i2c *i2c)
332 u8 fifo_space = xiic_tx_fifo_space(i2c);
333 int len = xiic_tx_space(i2c);
335 len = (len > fifo_space) ? fifo_space : len;
337 dev_dbg(i2c->adap.dev.parent, "%s entry, len: %d, fifo space: %d\n",
338 __func__, len, fifo_space);
341 u16 data = i2c->tx_msg->buf[i2c->tx_pos++];
342 if ((xiic_tx_space(i2c) == 0) && (i2c->nmsgs == 1)) {
343 /* last message in transfer -> STOP */
344 data |= XIIC_TX_DYN_STOP_MASK;
345 dev_dbg(i2c->adap.dev.parent, "%s TX STOP\n", __func__);
347 xiic_setreg16(i2c, XIIC_DTR_REG_OFFSET, data);
351 static void xiic_wakeup(struct xiic_i2c *i2c, int code)
360 static irqreturn_t xiic_process(int irq, void *dev_id)
362 struct xiic_i2c *i2c = dev_id;
369 /* Get the interrupt Status from the IPIF. There is no clearing of
370 * interrupts in the IPIF. Interrupts must be cleared at the source.
371 * To find which interrupts are pending; AND interrupts pending with
374 mutex_lock(&i2c->lock);
375 isr = xiic_getreg32(i2c, XIIC_IISR_OFFSET);
376 ier = xiic_getreg32(i2c, XIIC_IIER_OFFSET);
379 dev_dbg(i2c->adap.dev.parent, "%s: IER: 0x%x, ISR: 0x%x, pend: 0x%x\n",
380 __func__, ier, isr, pend);
381 dev_dbg(i2c->adap.dev.parent, "%s: SR: 0x%x, msg: %p, nmsgs: %d\n",
382 __func__, xiic_getreg8(i2c, XIIC_SR_REG_OFFSET),
383 i2c->tx_msg, i2c->nmsgs);
386 /* Service requesting interrupt */
387 if ((pend & XIIC_INTR_ARB_LOST_MASK) ||
388 ((pend & XIIC_INTR_TX_ERROR_MASK) &&
389 !(pend & XIIC_INTR_RX_FULL_MASK))) {
390 /* bus arbritration lost, or...
391 * Transmit error _OR_ RX completed
392 * if this happens when RX_FULL is not set
393 * this is probably a TX error
396 dev_dbg(i2c->adap.dev.parent, "%s error\n", __func__);
398 /* dynamic mode seem to suffer from problems if we just flushes
399 * fifos and the next message is a TX with len 0 (only addr)
400 * reset the IP instead of just flush fifos
406 wakeup_code = STATE_ERROR;
410 wakeup_code = STATE_ERROR;
412 /* don't try to handle other events */
415 if (pend & XIIC_INTR_RX_FULL_MASK) {
416 /* Receive register/FIFO is full */
418 clr |= XIIC_INTR_RX_FULL_MASK;
420 dev_dbg(i2c->adap.dev.parent,
421 "%s unexpected RX IRQ\n", __func__);
422 xiic_clear_rx_fifo(i2c);
427 if (xiic_rx_space(i2c) == 0) {
428 /* this is the last part of the message */
431 /* also clear TX error if there (RX complete) */
432 clr |= (isr & XIIC_INTR_TX_ERROR_MASK);
434 dev_dbg(i2c->adap.dev.parent,
435 "%s end of message, nmsgs: %d\n",
436 __func__, i2c->nmsgs);
438 /* send next message if this wasn't the last,
439 * otherwise the transfer will be finialise when
440 * receiving the bus not busy interrupt
442 if (i2c->nmsgs > 1) {
445 dev_dbg(i2c->adap.dev.parent,
446 "%s will start next...\n", __func__);
451 if (pend & XIIC_INTR_BNB_MASK) {
452 /* IIC bus has transitioned to not busy */
453 clr |= XIIC_INTR_BNB_MASK;
455 /* The bus is not busy, disable BusNotBusy interrupt */
456 xiic_irq_dis(i2c, XIIC_INTR_BNB_MASK);
463 if (i2c->nmsgs == 1 && !i2c->rx_msg &&
464 xiic_tx_space(i2c) == 0)
465 wakeup_code = STATE_DONE;
467 wakeup_code = STATE_ERROR;
469 if (pend & (XIIC_INTR_TX_EMPTY_MASK | XIIC_INTR_TX_HALF_MASK)) {
470 /* Transmit register/FIFO is empty or ½ empty */
473 (XIIC_INTR_TX_EMPTY_MASK | XIIC_INTR_TX_HALF_MASK));
476 dev_dbg(i2c->adap.dev.parent,
477 "%s unexpected TX IRQ\n", __func__);
481 xiic_fill_tx_fifo(i2c);
483 /* current message sent and there is space in the fifo */
484 if (!xiic_tx_space(i2c) && xiic_tx_fifo_space(i2c) >= 2) {
485 dev_dbg(i2c->adap.dev.parent,
486 "%s end of message sent, nmsgs: %d\n",
487 __func__, i2c->nmsgs);
488 if (i2c->nmsgs > 1) {
493 xiic_irq_dis(i2c, XIIC_INTR_TX_HALF_MASK);
495 dev_dbg(i2c->adap.dev.parent,
496 "%s Got TX IRQ but no more to do...\n",
499 } else if (!xiic_tx_space(i2c) && (i2c->nmsgs == 1))
500 /* current frame is sent and is last,
501 * make sure to disable tx half
503 xiic_irq_dis(i2c, XIIC_INTR_TX_HALF_MASK);
506 dev_dbg(i2c->adap.dev.parent, "%s clr: 0x%x\n", __func__, clr);
508 xiic_setreg32(i2c, XIIC_IISR_OFFSET, clr);
510 __xiic_start_xfer(i2c);
512 xiic_wakeup(i2c, wakeup_code);
514 WARN_ON(xfer_more && wakeup_req);
516 mutex_unlock(&i2c->lock);
520 static int xiic_bus_busy(struct xiic_i2c *i2c)
522 u8 sr = xiic_getreg8(i2c, XIIC_SR_REG_OFFSET);
524 return (sr & XIIC_SR_BUS_BUSY_MASK) ? -EBUSY : 0;
527 static int xiic_busy(struct xiic_i2c *i2c)
535 /* for instance if previous transfer was terminated due to TX error
536 * it might be that the bus is on it's way to become available
537 * give it at most 3 ms to wake
539 err = xiic_bus_busy(i2c);
540 while (err && tries--) {
542 err = xiic_bus_busy(i2c);
548 static void xiic_start_recv(struct xiic_i2c *i2c)
551 struct i2c_msg *msg = i2c->rx_msg = i2c->tx_msg;
554 /* Clear and enable Rx full interrupt. */
555 xiic_irq_clr_en(i2c, XIIC_INTR_RX_FULL_MASK | XIIC_INTR_TX_ERROR_MASK);
557 /* we want to get all but last byte, because the TX_ERROR IRQ is used
558 * to inidicate error ACK on the address, and negative ack on the last
559 * received byte, so to not mix them receive all but last.
560 * In the case where there is only one byte to receive
561 * we can check if ERROR and RX full is set at the same time
563 rx_watermark = msg->len;
564 if (rx_watermark > IIC_RX_FIFO_DEPTH)
565 rx_watermark = IIC_RX_FIFO_DEPTH;
566 xiic_setreg8(i2c, XIIC_RFD_REG_OFFSET, rx_watermark - 1);
568 local_irq_save(flags);
569 if (!(msg->flags & I2C_M_NOSTART))
570 /* write the address */
571 xiic_setreg16(i2c, XIIC_DTR_REG_OFFSET,
572 i2c_8bit_addr_from_msg(msg) | XIIC_TX_DYN_START_MASK);
574 xiic_irq_clr_en(i2c, XIIC_INTR_BNB_MASK);
576 xiic_setreg16(i2c, XIIC_DTR_REG_OFFSET,
577 msg->len | ((i2c->nmsgs == 1) ? XIIC_TX_DYN_STOP_MASK : 0));
578 local_irq_restore(flags);
581 /* very last, enable bus not busy as well */
582 xiic_irq_clr_en(i2c, XIIC_INTR_BNB_MASK);
584 /* the message is tx:ed */
585 i2c->tx_pos = msg->len;
588 static void xiic_start_send(struct xiic_i2c *i2c)
590 struct i2c_msg *msg = i2c->tx_msg;
592 xiic_irq_clr(i2c, XIIC_INTR_TX_ERROR_MASK);
594 dev_dbg(i2c->adap.dev.parent, "%s entry, msg: %p, len: %d",
595 __func__, msg, msg->len);
596 dev_dbg(i2c->adap.dev.parent, "%s entry, ISR: 0x%x, CR: 0x%x\n",
597 __func__, xiic_getreg32(i2c, XIIC_IISR_OFFSET),
598 xiic_getreg8(i2c, XIIC_CR_REG_OFFSET));
600 if (!(msg->flags & I2C_M_NOSTART)) {
601 /* write the address */
602 u16 data = i2c_8bit_addr_from_msg(msg) |
603 XIIC_TX_DYN_START_MASK;
604 if ((i2c->nmsgs == 1) && msg->len == 0)
605 /* no data and last message -> add STOP */
606 data |= XIIC_TX_DYN_STOP_MASK;
608 xiic_setreg16(i2c, XIIC_DTR_REG_OFFSET, data);
611 xiic_fill_tx_fifo(i2c);
613 /* Clear any pending Tx empty, Tx Error and then enable them. */
614 xiic_irq_clr_en(i2c, XIIC_INTR_TX_EMPTY_MASK | XIIC_INTR_TX_ERROR_MASK |
618 static irqreturn_t xiic_isr(int irq, void *dev_id)
620 struct xiic_i2c *i2c = dev_id;
622 irqreturn_t ret = IRQ_NONE;
623 /* Do not processes a devices interrupts if the device has no
627 dev_dbg(i2c->adap.dev.parent, "%s entry\n", __func__);
629 isr = xiic_getreg32(i2c, XIIC_IISR_OFFSET);
630 ier = xiic_getreg32(i2c, XIIC_IIER_OFFSET);
633 ret = IRQ_WAKE_THREAD;
638 static void __xiic_start_xfer(struct xiic_i2c *i2c)
641 int fifo_space = xiic_tx_fifo_space(i2c);
642 dev_dbg(i2c->adap.dev.parent, "%s entry, msg: %p, fifos space: %d\n",
643 __func__, i2c->tx_msg, fifo_space);
650 i2c->state = STATE_START;
651 while ((fifo_space >= 2) && (first || (i2c->nmsgs > 1))) {
659 if (i2c->tx_msg->flags & I2C_M_RD) {
660 /* we dont date putting several reads in the FIFO */
661 xiic_start_recv(i2c);
664 xiic_start_send(i2c);
665 if (xiic_tx_space(i2c) != 0) {
666 /* the message could not be completely sent */
671 fifo_space = xiic_tx_fifo_space(i2c);
674 /* there are more messages or the current one could not be completely
675 * put into the FIFO, also enable the half empty interrupt
677 if (i2c->nmsgs > 1 || xiic_tx_space(i2c))
678 xiic_irq_clr_en(i2c, XIIC_INTR_TX_HALF_MASK);
682 static void xiic_start_xfer(struct xiic_i2c *i2c)
684 mutex_lock(&i2c->lock);
686 __xiic_start_xfer(i2c);
687 mutex_unlock(&i2c->lock);
690 static int xiic_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
692 struct xiic_i2c *i2c = i2c_get_adapdata(adap);
695 dev_dbg(adap->dev.parent, "%s entry SR: 0x%x\n", __func__,
696 xiic_getreg8(i2c, XIIC_SR_REG_OFFSET));
698 err = pm_runtime_get_sync(i2c->dev);
702 err = xiic_busy(i2c);
709 xiic_start_xfer(i2c);
711 if (wait_event_timeout(i2c->wait, (i2c->state == STATE_ERROR) ||
712 (i2c->state == STATE_DONE), HZ)) {
713 err = (i2c->state == STATE_DONE) ? num : -EIO;
723 pm_runtime_mark_last_busy(i2c->dev);
724 pm_runtime_put_autosuspend(i2c->dev);
728 static u32 xiic_func(struct i2c_adapter *adap)
730 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
733 static const struct i2c_algorithm xiic_algorithm = {
734 .master_xfer = xiic_xfer,
735 .functionality = xiic_func,
738 static const struct i2c_adapter_quirks xiic_quirks = {
742 static const struct i2c_adapter xiic_adapter = {
743 .owner = THIS_MODULE,
744 .class = I2C_CLASS_DEPRECATED,
745 .algo = &xiic_algorithm,
746 .quirks = &xiic_quirks,
750 static int xiic_i2c_probe(struct platform_device *pdev)
752 struct xiic_i2c *i2c;
753 struct xiic_i2c_platform_data *pdata;
754 struct resource *res;
759 i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL);
763 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
764 i2c->base = devm_ioremap_resource(&pdev->dev, res);
765 if (IS_ERR(i2c->base))
766 return PTR_ERR(i2c->base);
768 irq = platform_get_irq(pdev, 0);
772 pdata = dev_get_platdata(&pdev->dev);
774 /* hook up driver to tree */
775 platform_set_drvdata(pdev, i2c);
776 i2c->adap = xiic_adapter;
777 i2c_set_adapdata(&i2c->adap, i2c);
778 i2c->adap.dev.parent = &pdev->dev;
779 i2c->adap.dev.of_node = pdev->dev.of_node;
780 snprintf(i2c->adap.name, sizeof(i2c->adap.name),
781 DRIVER_NAME " %s", pdev->name);
783 mutex_init(&i2c->lock);
784 init_waitqueue_head(&i2c->wait);
786 i2c->clk = devm_clk_get(&pdev->dev, NULL);
787 if (IS_ERR(i2c->clk)) {
788 dev_err(&pdev->dev, "input clock not found.\n");
789 return PTR_ERR(i2c->clk);
791 ret = clk_prepare_enable(i2c->clk);
793 dev_err(&pdev->dev, "Unable to enable clock.\n");
796 i2c->dev = &pdev->dev;
797 pm_runtime_enable(i2c->dev);
798 pm_runtime_set_autosuspend_delay(i2c->dev, XIIC_PM_TIMEOUT);
799 pm_runtime_use_autosuspend(i2c->dev);
800 pm_runtime_set_active(i2c->dev);
801 ret = devm_request_threaded_irq(&pdev->dev, irq, xiic_isr,
802 xiic_process, IRQF_ONESHOT,
806 dev_err(&pdev->dev, "Cannot claim IRQ\n");
812 * Try to reset the TX FIFO. Then check the EMPTY flag. If it is not
813 * set, assume that the endianness was wrong and swap.
815 i2c->endianness = LITTLE;
816 xiic_setreg32(i2c, XIIC_CR_REG_OFFSET, XIIC_CR_TX_FIFO_RESET_MASK);
817 /* Reset is cleared in xiic_reinit */
818 sr = xiic_getreg32(i2c, XIIC_SR_REG_OFFSET);
819 if (!(sr & XIIC_SR_TX_FIFO_EMPTY_MASK))
820 i2c->endianness = BIG;
824 /* add i2c adapter to i2c tree */
825 ret = i2c_add_adapter(&i2c->adap);
832 /* add in known devices to the bus */
833 for (i = 0; i < pdata->num_devices; i++)
834 i2c_new_device(&i2c->adap, pdata->devices + i);
840 pm_runtime_set_suspended(&pdev->dev);
841 pm_runtime_disable(&pdev->dev);
842 clk_disable_unprepare(i2c->clk);
846 static int xiic_i2c_remove(struct platform_device *pdev)
848 struct xiic_i2c *i2c = platform_get_drvdata(pdev);
851 /* remove adapter & data */
852 i2c_del_adapter(&i2c->adap);
854 ret = clk_prepare_enable(i2c->clk);
856 dev_err(&pdev->dev, "Unable to enable clock.\n");
860 clk_disable_unprepare(i2c->clk);
861 pm_runtime_disable(&pdev->dev);
866 #if defined(CONFIG_OF)
867 static const struct of_device_id xiic_of_match[] = {
868 { .compatible = "xlnx,xps-iic-2.00.a", },
871 MODULE_DEVICE_TABLE(of, xiic_of_match);
874 static int __maybe_unused xiic_i2c_runtime_suspend(struct device *dev)
876 struct xiic_i2c *i2c = dev_get_drvdata(dev);
878 clk_disable(i2c->clk);
883 static int __maybe_unused xiic_i2c_runtime_resume(struct device *dev)
885 struct xiic_i2c *i2c = dev_get_drvdata(dev);
888 ret = clk_enable(i2c->clk);
890 dev_err(dev, "Cannot enable clock.\n");
897 static const struct dev_pm_ops xiic_dev_pm_ops = {
898 SET_RUNTIME_PM_OPS(xiic_i2c_runtime_suspend,
899 xiic_i2c_runtime_resume, NULL)
901 static struct platform_driver xiic_i2c_driver = {
902 .probe = xiic_i2c_probe,
903 .remove = xiic_i2c_remove,
906 .of_match_table = of_match_ptr(xiic_of_match),
907 .pm = &xiic_dev_pm_ops,
911 module_platform_driver(xiic_i2c_driver);
913 MODULE_ALIAS("platform:" DRIVER_NAME);
914 MODULE_AUTHOR("info@mocean-labs.com");
915 MODULE_DESCRIPTION("Xilinx I2C bus driver");
916 MODULE_LICENSE("GPL v2");
917 MODULE_ALIAS("platform:"DRIVER_NAME);