Merge remote-tracking branch 'asoc/topic/pcm5102a' into asoc-next
[linux-2.6-block.git] / drivers / i2c / busses / i2c-designware-master.c
CommitLineData
1ab52cf9 1/*
a0e06ea6 2 * Synopsys DesignWare I2C adapter driver (master only).
1ab52cf9
BS
3 *
4 * Based on the TI DAVINCI I2C adapter driver.
5 *
6 * Copyright (C) 2006 Texas Instruments.
7 * Copyright (C) 2007 MontaVista Software Inc.
8 * Copyright (C) 2009 Provigent Ltd.
9 *
10 * ----------------------------------------------------------------------------
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
16 *
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
1ab52cf9
BS
21 * ----------------------------------------------------------------------------
22 *
23 */
e393f674 24#include <linux/delay.h>
1ab52cf9 25#include <linux/err.h>
90312351
LO
26#include <linux/errno.h>
27#include <linux/export.h>
ca382f5b 28#include <linux/gpio/consumer.h>
2373f6b9 29#include <linux/i2c.h>
1ab52cf9 30#include <linux/interrupt.h>
1ab52cf9 31#include <linux/io.h>
9dd3162d 32#include <linux/module.h>
e393f674 33#include <linux/pm_runtime.h>
ca382f5b 34#include <linux/reset.h>
ce6eb574 35
e393f674 36#include "i2c-designware-core.h"
7f279601 37
89a1e1bd
LO
38static void i2c_dw_configure_fifo_master(struct dw_i2c_dev *dev)
39{
40 /* Configure Tx/Rx FIFO threshold levels */
41 dw_writel(dev, dev->tx_fifo_depth / 2, DW_IC_TX_TL);
42 dw_writel(dev, 0, DW_IC_RX_TL);
43
44 /* Configure the I2C master */
45 dw_writel(dev, dev->master_cfg, DW_IC_CON);
46}
47
1ab52cf9 48/**
e393f674 49 * i2c_dw_init() - Initialize the designware I2C master hardware
1ab52cf9
BS
50 * @dev: device private data
51 *
52 * This functions configures and enables the I2C master.
53 * This function is called during I2C init function, and in case of timeout at
54 * run time.
55 */
21bf440c 56static int i2c_dw_init_master(struct dw_i2c_dev *dev)
1ab52cf9 57{
e18563fc 58 u32 hcnt, lcnt;
b6e67145 59 u32 reg, comp_param1;
6468276b 60 u32 sda_falling_time, scl_falling_time;
c0601d28
DB
61 int ret;
62
8c5660bb
LDM
63 ret = i2c_dw_acquire_lock(dev);
64 if (ret)
65 return ret;
4a423a8c 66
4a423a8c
DB
67 reg = dw_readl(dev, DW_IC_COMP_TYPE);
68 if (reg == ___constant_swab32(DW_IC_COMP_TYPE_VALUE)) {
a8a9f3fe 69 /* Configure register endianess access */
86524e54 70 dev->flags |= ACCESS_SWAP;
a8a9f3fe
SR
71 } else if (reg == (DW_IC_COMP_TYPE_VALUE & 0x0000ffff)) {
72 /* Configure register access mode 16bit */
86524e54 73 dev->flags |= ACCESS_16BIT;
a8a9f3fe 74 } else if (reg != DW_IC_COMP_TYPE_VALUE) {
e393f674
LO
75 dev_err(dev->dev,
76 "Unknown Synopsys component type: 0x%08x\n", reg);
8c5660bb 77 i2c_dw_release_lock(dev);
4a423a8c
DB
78 return -ENODEV;
79 }
1ab52cf9 80
b6e67145
WV
81 comp_param1 = dw_readl(dev, DW_IC_COMP_PARAM_1);
82
1ab52cf9 83 /* Disable the adapter */
2702ea7d 84 __i2c_dw_enable_and_wait(dev, false);
1ab52cf9 85
e393f674 86 /* Set standard and fast speed deviders for high/low periods */
d60c7e81 87
6468276b
RB
88 sda_falling_time = dev->sda_falling_time ?: 300; /* ns */
89 scl_falling_time = dev->scl_falling_time ?: 300; /* ns */
90
42ffd390 91 /* Set SCL timing parameters for standard-mode */
defc0b2f
MW
92 if (dev->ss_hcnt && dev->ss_lcnt) {
93 hcnt = dev->ss_hcnt;
94 lcnt = dev->ss_lcnt;
42ffd390 95 } else {
b33af11d 96 hcnt = i2c_dw_scl_hcnt(i2c_dw_clk_rate(dev),
42ffd390
JN
97 4000, /* tHD;STA = tHIGH = 4.0 us */
98 sda_falling_time,
99 0, /* 0: DW default, 1: Ideal */
100 0); /* No offset */
b33af11d 101 lcnt = i2c_dw_scl_lcnt(i2c_dw_clk_rate(dev),
42ffd390
JN
102 4700, /* tLOW = 4.7 us */
103 scl_falling_time,
104 0); /* No offset */
defc0b2f 105 }
7f279601
JHD
106 dw_writel(dev, hcnt, DW_IC_SS_SCL_HCNT);
107 dw_writel(dev, lcnt, DW_IC_SS_SCL_LCNT);
d60c7e81
SK
108 dev_dbg(dev->dev, "Standard-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt);
109
d608c3d9
WV
110 /* Set SCL timing parameters for fast-mode or fast-mode plus */
111 if ((dev->clk_freq == 1000000) && dev->fp_hcnt && dev->fp_lcnt) {
112 hcnt = dev->fp_hcnt;
113 lcnt = dev->fp_lcnt;
114 } else if (dev->fs_hcnt && dev->fs_lcnt) {
defc0b2f
MW
115 hcnt = dev->fs_hcnt;
116 lcnt = dev->fs_lcnt;
42ffd390 117 } else {
b33af11d 118 hcnt = i2c_dw_scl_hcnt(i2c_dw_clk_rate(dev),
42ffd390
JN
119 600, /* tHD;STA = tHIGH = 0.6 us */
120 sda_falling_time,
121 0, /* 0: DW default, 1: Ideal */
122 0); /* No offset */
b33af11d 123 lcnt = i2c_dw_scl_lcnt(i2c_dw_clk_rate(dev),
42ffd390
JN
124 1300, /* tLOW = 1.3 us */
125 scl_falling_time,
126 0); /* No offset */
defc0b2f 127 }
7f279601
JHD
128 dw_writel(dev, hcnt, DW_IC_FS_SCL_HCNT);
129 dw_writel(dev, lcnt, DW_IC_FS_SCL_LCNT);
d60c7e81 130 dev_dbg(dev->dev, "Fast-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt);
1ab52cf9 131
b6e67145
WV
132 if ((dev->master_cfg & DW_IC_CON_SPEED_MASK) ==
133 DW_IC_CON_SPEED_HIGH) {
134 if ((comp_param1 & DW_IC_COMP_PARAM_1_SPEED_MODE_MASK)
135 != DW_IC_COMP_PARAM_1_SPEED_MODE_HIGH) {
136 dev_err(dev->dev, "High Speed not supported!\n");
137 dev->master_cfg &= ~DW_IC_CON_SPEED_MASK;
138 dev->master_cfg |= DW_IC_CON_SPEED_FAST;
139 } else if (dev->hs_hcnt && dev->hs_lcnt) {
140 hcnt = dev->hs_hcnt;
141 lcnt = dev->hs_lcnt;
142 dw_writel(dev, hcnt, DW_IC_HS_SCL_HCNT);
143 dw_writel(dev, lcnt, DW_IC_HS_SCL_LCNT);
144 dev_dbg(dev->dev, "HighSpeed-mode HCNT:LCNT = %d:%d\n",
145 hcnt, lcnt);
146 }
147 }
148
9803f868 149 /* Configure SDA Hold Time if required */
664d58bf
ZL
150 reg = dw_readl(dev, DW_IC_COMP_VERSION);
151 if (reg >= DW_IC_SDA_HOLD_MIN_VERS) {
171e23e1 152 if (!dev->sda_hold_time) {
664d58bf
ZL
153 /* Keep previous hold time setting if no one set it */
154 dev->sda_hold_time = dw_readl(dev, DW_IC_SDA_HOLD);
155 }
171e23e1
JN
156 /*
157 * Workaround for avoiding TX arbitration lost in case I2C
158 * slave pulls SDA down "too quickly" after falling egde of
159 * SCL by enabling non-zero SDA RX hold. Specification says it
160 * extends incoming SDA low to high transition while SCL is
161 * high but it apprears to help also above issue.
162 */
163 if (!(dev->sda_hold_time & DW_IC_SDA_HOLD_RX_MASK))
164 dev->sda_hold_time |= 1 << DW_IC_SDA_HOLD_RX_SHIFT;
165 dw_writel(dev, dev->sda_hold_time, DW_IC_SDA_HOLD);
664d58bf
ZL
166 } else {
167 dev_warn(dev->dev,
168 "Hardware too old to adjust SDA hold time.\n");
9803f868
CR
169 }
170
89a1e1bd 171 i2c_dw_configure_fifo_master(dev);
8c5660bb
LDM
172 i2c_dw_release_lock(dev);
173
4a423a8c 174 return 0;
1ab52cf9
BS
175}
176
81e798b7
SK
177static void i2c_dw_xfer_init(struct dw_i2c_dev *dev)
178{
179 struct i2c_msg *msgs = dev->msgs;
12688dc2 180 u32 ic_con, ic_tar = 0;
81e798b7 181
89119f08
JN
182 /* Disable the adapter */
183 __i2c_dw_enable_and_wait(dev, false);
81e798b7 184
e393f674 185 /* If the slave address is ten bit address, enable 10BITADDR */
12688dc2
JN
186 ic_con = dw_readl(dev, DW_IC_CON);
187 if (msgs[dev->msg_write_idx].flags & I2C_M_TEN) {
188 ic_con |= DW_IC_CON_10BITADDR_MASTER;
bd63ace4
CCE
189 /*
190 * If I2C_DYNAMIC_TAR_UPDATE is set, the 10-bit addressing
12688dc2
JN
191 * mode has to be enabled via bit 12 of IC_TAR register.
192 * We set it always as I2C_DYNAMIC_TAR_UPDATE can't be
193 * detected from registers.
bd63ace4 194 */
12688dc2 195 ic_tar = DW_IC_TAR_10BITADDR_MASTER;
bd63ace4 196 } else {
12688dc2 197 ic_con &= ~DW_IC_CON_10BITADDR_MASTER;
63d0f0a6 198 }
81e798b7 199
12688dc2
JN
200 dw_writel(dev, ic_con, DW_IC_CON);
201
bd63ace4
CCE
202 /*
203 * Set the slave (target) address and enable 10-bit addressing mode
204 * if applicable.
205 */
206 dw_writel(dev, msgs[dev->msg_write_idx].addr | ic_tar, DW_IC_TAR);
207
e393f674 208 /* Enforce disabled interrupts (due to HW issues) */
47bb27e7
DW
209 i2c_dw_disable_int(dev);
210
89119f08 211 /* Enable the adapter */
fba4adbb 212 __i2c_dw_enable_and_wait(dev, true);
201d6a70 213
2a2d95e9 214 /* Clear and enable interrupts */
c335631a 215 dw_readl(dev, DW_IC_CLR_INTR);
89a1e1bd 216 dw_writel(dev, DW_IC_INTR_MASTER_MASK, DW_IC_INTR_MASK);
81e798b7
SK
217}
218
1ab52cf9 219/*
201d6a70
SK
220 * Initiate (and continue) low level master read/write transaction.
221 * This function is only called from i2c_dw_isr, and pumping i2c_msg
222 * messages into the tx buffer. Even if the size of i2c_msg data is
223 * longer than the size of the tx buffer, it handles everything.
1ab52cf9 224 */
bccd780f 225static void
e77cf232 226i2c_dw_xfer_msg(struct dw_i2c_dev *dev)
1ab52cf9 227{
1ab52cf9 228 struct i2c_msg *msgs = dev->msgs;
81e798b7 229 u32 intr_mask;
ae72222d 230 int tx_limit, rx_limit;
ed5e1dd5
SK
231 u32 addr = msgs[dev->msg_write_idx].addr;
232 u32 buf_len = dev->tx_buf_len;
69932487 233 u8 *buf = dev->tx_buf;
82564245 234 bool need_restart = false;
1ab52cf9 235
89a1e1bd 236 intr_mask = DW_IC_INTR_MASTER_MASK;
c70c5cd3 237
6d2ea487 238 for (; dev->msg_write_idx < dev->msgs_num; dev->msg_write_idx++) {
c3ae1060
TH
239 u32 flags = msgs[dev->msg_write_idx].flags;
240
a0e06ea6 241 /*
e393f674
LO
242 * If target address has changed, we need to
243 * reprogram the target address in the I2C
244 * adapter when we are done with this transfer.
1ab52cf9 245 */
8f588e40
SK
246 if (msgs[dev->msg_write_idx].addr != addr) {
247 dev_err(dev->dev,
248 "%s: invalid target address\n", __func__);
249 dev->msg_err = -EINVAL;
250 break;
251 }
1ab52cf9
BS
252
253 if (msgs[dev->msg_write_idx].len == 0) {
254 dev_err(dev->dev,
255 "%s: invalid message length\n", __func__);
256 dev->msg_err = -EINVAL;
8f588e40 257 break;
1ab52cf9
BS
258 }
259
260 if (!(dev->status & STATUS_WRITE_IN_PROGRESS)) {
261 /* new i2c_msg */
26ea15b1 262 buf = msgs[dev->msg_write_idx].buf;
1ab52cf9 263 buf_len = msgs[dev->msg_write_idx].len;
82564245
CCE
264
265 /* If both IC_EMPTYFIFO_HOLD_MASTER_EN and
266 * IC_RESTART_EN are set, we must manually
267 * set restart bit between messages.
268 */
269 if ((dev->master_cfg & DW_IC_CON_RESTART_EN) &&
270 (dev->msg_write_idx > 0))
271 need_restart = true;
1ab52cf9
BS
272 }
273
7f279601
JHD
274 tx_limit = dev->tx_fifo_depth - dw_readl(dev, DW_IC_TXFLR);
275 rx_limit = dev->rx_fifo_depth - dw_readl(dev, DW_IC_RXFLR);
ae72222d 276
1ab52cf9 277 while (buf_len > 0 && tx_limit > 0 && rx_limit > 0) {
17a76b4b
MW
278 u32 cmd = 0;
279
280 /*
281 * If IC_EMPTYFIFO_HOLD_MASTER_EN is set we must
282 * manually set the stop bit. However, it cannot be
283 * detected from the registers so we set it always
284 * when writing/reading the last byte.
285 */
c3ae1060
TH
286
287 /*
91ed5349 288 * i2c-core always sets the buffer length of
c3ae1060
TH
289 * I2C_FUNC_SMBUS_BLOCK_DATA to 1. The length will
290 * be adjusted when receiving the first byte.
291 * Thus we can't stop the transaction here.
292 */
17a76b4b 293 if (dev->msg_write_idx == dev->msgs_num - 1 &&
c3ae1060 294 buf_len == 1 && !(flags & I2C_M_RECV_LEN))
17a76b4b
MW
295 cmd |= BIT(9);
296
82564245
CCE
297 if (need_restart) {
298 cmd |= BIT(10);
299 need_restart = false;
300 }
301
1ab52cf9 302 if (msgs[dev->msg_write_idx].flags & I2C_M_RD) {
e6f34cea 303
e393f674 304 /* Avoid rx buffer overrun */
4d6d5f1d 305 if (dev->rx_outstanding >= dev->rx_fifo_depth)
e6f34cea
JA
306 break;
307
17a76b4b 308 dw_writel(dev, cmd | 0x100, DW_IC_DATA_CMD);
1ab52cf9 309 rx_limit--;
e6f34cea 310 dev->rx_outstanding++;
1ab52cf9 311 } else
17a76b4b 312 dw_writel(dev, cmd | *buf++, DW_IC_DATA_CMD);
1ab52cf9
BS
313 tx_limit--; buf_len--;
314 }
c70c5cd3 315
26ea15b1 316 dev->tx_buf = buf;
c70c5cd3
SK
317 dev->tx_buf_len = buf_len;
318
c3ae1060
TH
319 /*
320 * Because we don't know the buffer length in the
321 * I2C_FUNC_SMBUS_BLOCK_DATA case, we can't stop
322 * the transaction here.
323 */
324 if (buf_len > 0 || flags & I2C_M_RECV_LEN) {
c70c5cd3 325 /* more bytes to be written */
c70c5cd3
SK
326 dev->status |= STATUS_WRITE_IN_PROGRESS;
327 break;
69151e53 328 } else
c70c5cd3 329 dev->status &= ~STATUS_WRITE_IN_PROGRESS;
1ab52cf9
BS
330 }
331
69151e53
SK
332 /*
333 * If i2c_msg index search is completed, we don't need TX_EMPTY
334 * interrupt any more.
335 */
336 if (dev->msg_write_idx == dev->msgs_num)
337 intr_mask &= ~DW_IC_INTR_TX_EMPTY;
338
8f588e40
SK
339 if (dev->msg_err)
340 intr_mask = 0;
341
2373f6b9 342 dw_writel(dev, intr_mask, DW_IC_INTR_MASK);
1ab52cf9
BS
343}
344
c3ae1060
TH
345static u8
346i2c_dw_recv_len(struct dw_i2c_dev *dev, u8 len)
347{
348 struct i2c_msg *msgs = dev->msgs;
349 u32 flags = msgs[dev->msg_read_idx].flags;
350
351 /*
352 * Adjust the buffer length and mask the flag
353 * after receiving the first byte.
354 */
355 len += (flags & I2C_CLIENT_PEC) ? 2 : 1;
356 dev->tx_buf_len = len - min_t(u8, len, dev->rx_outstanding);
357 msgs[dev->msg_read_idx].len = len;
358 msgs[dev->msg_read_idx].flags &= ~I2C_M_RECV_LEN;
359
360 return len;
361}
362
1ab52cf9 363static void
78839bd0 364i2c_dw_read(struct dw_i2c_dev *dev)
1ab52cf9 365{
1ab52cf9 366 struct i2c_msg *msgs = dev->msgs;
ae72222d 367 int rx_valid;
1ab52cf9 368
6d2ea487 369 for (; dev->msg_read_idx < dev->msgs_num; dev->msg_read_idx++) {
ed5e1dd5 370 u32 len;
1ab52cf9
BS
371 u8 *buf;
372
373 if (!(msgs[dev->msg_read_idx].flags & I2C_M_RD))
374 continue;
375
1ab52cf9
BS
376 if (!(dev->status & STATUS_READ_IN_PROGRESS)) {
377 len = msgs[dev->msg_read_idx].len;
378 buf = msgs[dev->msg_read_idx].buf;
379 } else {
380 len = dev->rx_buf_len;
381 buf = dev->rx_buf;
382 }
383
7f279601 384 rx_valid = dw_readl(dev, DW_IC_RXFLR);
ae72222d 385
e6f34cea 386 for (; len > 0 && rx_valid > 0; len--, rx_valid--) {
c3ae1060
TH
387 u32 flags = msgs[dev->msg_read_idx].flags;
388
389 *buf = dw_readl(dev, DW_IC_DATA_CMD);
390 /* Ensure length byte is a valid value */
391 if (flags & I2C_M_RECV_LEN &&
392 *buf <= I2C_SMBUS_BLOCK_MAX && *buf > 0) {
393 len = i2c_dw_recv_len(dev, *buf);
394 }
395 buf++;
e6f34cea
JA
396 dev->rx_outstanding--;
397 }
1ab52cf9
BS
398
399 if (len > 0) {
400 dev->status |= STATUS_READ_IN_PROGRESS;
401 dev->rx_buf_len = len;
402 dev->rx_buf = buf;
403 return;
404 } else
405 dev->status &= ~STATUS_READ_IN_PROGRESS;
406 }
407}
408
409/*
e393f674 410 * Prepare controller for a transaction and call i2c_dw_xfer_msg.
1ab52cf9 411 */
d80d1341 412static int
1ab52cf9
BS
413i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
414{
415 struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
416 int ret;
417
418 dev_dbg(dev->dev, "%s: msgs: %d\n", __func__, num);
419
18dbdda8 420 pm_runtime_get_sync(dev->dev);
1ab52cf9 421
16735d02 422 reinit_completion(&dev->cmd_complete);
1ab52cf9
BS
423 dev->msgs = msgs;
424 dev->msgs_num = num;
425 dev->cmd_err = 0;
426 dev->msg_write_idx = 0;
427 dev->msg_read_idx = 0;
428 dev->msg_err = 0;
429 dev->status = STATUS_IDLE;
ce6eb574 430 dev->abort_source = 0;
e6f34cea 431 dev->rx_outstanding = 0;
1ab52cf9 432
8c5660bb
LDM
433 ret = i2c_dw_acquire_lock(dev);
434 if (ret)
435 goto done_nolock;
c0601d28 436
1ab52cf9
BS
437 ret = i2c_dw_wait_bus_not_busy(dev);
438 if (ret < 0)
439 goto done;
440
e393f674 441 /* Start the transfers */
81e798b7 442 i2c_dw_xfer_init(dev);
1ab52cf9 443
e393f674 444 /* Wait for tx to complete */
d0bcd8df 445 if (!wait_for_completion_timeout(&dev->cmd_complete, adap->timeout)) {
1ab52cf9 446 dev_err(dev->dev, "controller timed out\n");
38d7fade 447 /* i2c_dw_init implicitly disables the adapter */
ca382f5b 448 i2c_recover_bus(&dev->adapter);
21bf440c 449 i2c_dw_init_master(dev);
1ab52cf9
BS
450 ret = -ETIMEDOUT;
451 goto done;
e42dba56 452 }
1ab52cf9 453
89119f08
JN
454 /*
455 * We must disable the adapter before returning and signaling the end
456 * of the current transfer. Otherwise the hardware might continue
457 * generating interrupts which in turn causes a race condition with
458 * the following transfer. Needs some more investigation if the
459 * additional interrupts are a hardware bug or this driver doesn't
460 * handle them correctly yet.
461 */
462 __i2c_dw_enable(dev, false);
463
1ab52cf9
BS
464 if (dev->msg_err) {
465 ret = dev->msg_err;
466 goto done;
467 }
468
e393f674 469 /* No error */
2bf413d5 470 if (likely(!dev->cmd_err && !dev->status)) {
1ab52cf9
BS
471 ret = num;
472 goto done;
473 }
474
475 /* We have an error */
476 if (dev->cmd_err == DW_IC_ERR_TX_ABRT) {
ce6eb574
SK
477 ret = i2c_dw_handle_tx_abort(dev);
478 goto done;
1ab52cf9 479 }
2bf413d5
RK
480
481 if (dev->status)
482 dev_err(dev->dev,
483 "transfer terminated early - interrupt latency too high?\n");
484
1ab52cf9
BS
485 ret = -EIO;
486
487done:
8c5660bb 488 i2c_dw_release_lock(dev);
c0601d28
DB
489
490done_nolock:
43452335
MW
491 pm_runtime_mark_last_busy(dev->dev);
492 pm_runtime_put_autosuspend(dev->dev);
1ab52cf9
BS
493
494 return ret;
495}
496
92d9d0df 497static const struct i2c_algorithm i2c_dw_algo = {
e393f674
LO
498 .master_xfer = i2c_dw_xfer,
499 .functionality = i2c_dw_func,
d80d1341 500};
1ab52cf9 501
e28000a3
SK
502static u32 i2c_dw_read_clear_intrbits(struct dw_i2c_dev *dev)
503{
504 u32 stat;
505
506 /*
507 * The IC_INTR_STAT register just indicates "enabled" interrupts.
508 * Ths unmasked raw version of interrupt status bits are available
509 * in the IC_RAW_INTR_STAT register.
510 *
511 * That is,
2373f6b9 512 * stat = dw_readl(IC_INTR_STAT);
e28000a3 513 * equals to,
2373f6b9 514 * stat = dw_readl(IC_RAW_INTR_STAT) & dw_readl(IC_INTR_MASK);
e28000a3
SK
515 *
516 * The raw version might be useful for debugging purposes.
517 */
7f279601 518 stat = dw_readl(dev, DW_IC_INTR_STAT);
e28000a3
SK
519
520 /*
521 * Do not use the IC_CLR_INTR register to clear interrupts, or
522 * you'll miss some interrupts, triggered during the period from
2373f6b9 523 * dw_readl(IC_INTR_STAT) to dw_readl(IC_CLR_INTR).
e28000a3
SK
524 *
525 * Instead, use the separately-prepared IC_CLR_* registers.
526 */
527 if (stat & DW_IC_INTR_RX_UNDER)
7f279601 528 dw_readl(dev, DW_IC_CLR_RX_UNDER);
e28000a3 529 if (stat & DW_IC_INTR_RX_OVER)
7f279601 530 dw_readl(dev, DW_IC_CLR_RX_OVER);
e28000a3 531 if (stat & DW_IC_INTR_TX_OVER)
7f279601 532 dw_readl(dev, DW_IC_CLR_TX_OVER);
e28000a3 533 if (stat & DW_IC_INTR_RD_REQ)
7f279601 534 dw_readl(dev, DW_IC_CLR_RD_REQ);
e28000a3
SK
535 if (stat & DW_IC_INTR_TX_ABRT) {
536 /*
537 * The IC_TX_ABRT_SOURCE register is cleared whenever
538 * the IC_CLR_TX_ABRT is read. Preserve it beforehand.
539 */
7f279601
JHD
540 dev->abort_source = dw_readl(dev, DW_IC_TX_ABRT_SOURCE);
541 dw_readl(dev, DW_IC_CLR_TX_ABRT);
e28000a3
SK
542 }
543 if (stat & DW_IC_INTR_RX_DONE)
7f279601 544 dw_readl(dev, DW_IC_CLR_RX_DONE);
e28000a3 545 if (stat & DW_IC_INTR_ACTIVITY)
7f279601 546 dw_readl(dev, DW_IC_CLR_ACTIVITY);
e28000a3 547 if (stat & DW_IC_INTR_STOP_DET)
7f279601 548 dw_readl(dev, DW_IC_CLR_STOP_DET);
e28000a3 549 if (stat & DW_IC_INTR_START_DET)
7f279601 550 dw_readl(dev, DW_IC_CLR_START_DET);
e28000a3 551 if (stat & DW_IC_INTR_GEN_CALL)
7f279601 552 dw_readl(dev, DW_IC_CLR_GEN_CALL);
e28000a3
SK
553
554 return stat;
555}
556
1ab52cf9 557/*
89a1e1bd 558 * Interrupt service routine. This gets called whenever an I2C master interrupt
1ab52cf9
BS
559 * occurs.
560 */
89a1e1bd 561static int i2c_dw_irq_handler_master(struct dw_i2c_dev *dev)
1ab52cf9 562{
89a1e1bd 563 u32 stat;
1ab52cf9 564
e28000a3 565 stat = i2c_dw_read_clear_intrbits(dev);
1ab52cf9 566 if (stat & DW_IC_INTR_TX_ABRT) {
1ab52cf9
BS
567 dev->cmd_err |= DW_IC_ERR_TX_ABRT;
568 dev->status = STATUS_IDLE;
597fe310
SK
569
570 /*
571 * Anytime TX_ABRT is set, the contents of the tx/rx
e393f674 572 * buffers are flushed. Make sure to skip them.
597fe310 573 */
7f279601 574 dw_writel(dev, 0, DW_IC_INTR_MASK);
597fe310 575 goto tx_aborted;
07745399
SK
576 }
577
21a89d41 578 if (stat & DW_IC_INTR_RX_FULL)
07745399 579 i2c_dw_read(dev);
21a89d41
SK
580
581 if (stat & DW_IC_INTR_TX_EMPTY)
07745399 582 i2c_dw_xfer_msg(dev);
07745399
SK
583
584 /*
585 * No need to modify or disable the interrupt mask here.
586 * i2c_dw_xfer_msg() will take care of it according to
587 * the current transmit status.
588 */
1ab52cf9 589
597fe310 590tx_aborted:
89119f08 591 if ((stat & (DW_IC_INTR_TX_ABRT | DW_IC_INTR_STOP_DET)) || dev->msg_err)
1ab52cf9 592 complete(&dev->cmd_complete);
86524e54 593 else if (unlikely(dev->flags & ACCESS_INTR_MASK)) {
e393f674 594 /* Workaround to trigger pending interrupt */
2d244c81
XY
595 stat = dw_readl(dev, DW_IC_INTR_MASK);
596 i2c_dw_disable_int(dev);
597 dw_writel(dev, stat, DW_IC_INTR_MASK);
598 }
1ab52cf9 599
89a1e1bd
LO
600 return 0;
601}
602
603static irqreturn_t i2c_dw_isr(int this_irq, void *dev_id)
604{
605 struct dw_i2c_dev *dev = dev_id;
606 u32 stat, enabled;
607
608 enabled = dw_readl(dev, DW_IC_ENABLE);
609 stat = dw_readl(dev, DW_IC_RAW_INTR_STAT);
610 dev_dbg(dev->dev, "enabled=%#x stat=%#x\n", enabled, stat);
611 if (!enabled || !(stat & ~DW_IC_INTR_ACTIVITY))
612 return IRQ_NONE;
613
614 i2c_dw_irq_handler_master(dev);
615
1ab52cf9
BS
616 return IRQ_HANDLED;
617}
f3fa9f3d 618
ca382f5b
TS
619static void i2c_dw_prepare_recovery(struct i2c_adapter *adap)
620{
621 struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
622
623 i2c_dw_disable(dev);
624 reset_control_assert(dev->rst);
625 i2c_dw_prepare_clk(dev, false);
626}
627
628static void i2c_dw_unprepare_recovery(struct i2c_adapter *adap)
629{
630 struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
631
632 i2c_dw_prepare_clk(dev, true);
633 reset_control_deassert(dev->rst);
634 i2c_dw_init_master(dev);
635}
636
637static int i2c_dw_init_recovery_info(struct dw_i2c_dev *dev)
638{
639 struct i2c_bus_recovery_info *rinfo = &dev->rinfo;
640 struct i2c_adapter *adap = &dev->adapter;
641 struct gpio_desc *gpio;
642 int r;
643
644 gpio = devm_gpiod_get(dev->dev, "scl", GPIOD_OUT_HIGH);
645 if (IS_ERR(gpio)) {
646 r = PTR_ERR(gpio);
d1fa7452 647 if (r == -ENOENT || r == -ENOSYS)
ca382f5b
TS
648 return 0;
649 return r;
650 }
651 rinfo->scl_gpiod = gpio;
652
653 gpio = devm_gpiod_get_optional(dev->dev, "sda", GPIOD_IN);
654 if (IS_ERR(gpio))
655 return PTR_ERR(gpio);
656 rinfo->sda_gpiod = gpio;
657
658 rinfo->recover_bus = i2c_generic_scl_recovery;
659 rinfo->prepare_recovery = i2c_dw_prepare_recovery;
660 rinfo->unprepare_recovery = i2c_dw_unprepare_recovery;
661 adap->bus_recovery_info = rinfo;
662
663 dev_info(dev->dev, "running with gpio recovery mode! scl%s",
664 rinfo->sda_gpiod ? ",sda" : "");
665
666 return 0;
667}
668
d80d1341
JN
669int i2c_dw_probe(struct dw_i2c_dev *dev)
670{
671 struct i2c_adapter *adap = &dev->adapter;
41c80b8a 672 unsigned long irq_flags;
e393f674 673 int ret;
d80d1341
JN
674
675 init_completion(&dev->cmd_complete);
d80d1341 676
21bf440c 677 dev->init = i2c_dw_init_master;
90312351
LO
678 dev->disable = i2c_dw_disable;
679 dev->disable_int = i2c_dw_disable_int;
680
681 ret = dev->init(dev);
e393f674
LO
682 if (ret)
683 return ret;
d80d1341
JN
684
685 snprintf(adap->name, sizeof(adap->name),
686 "Synopsys DesignWare I2C adapter");
8d22f309 687 adap->retries = 3;
d80d1341
JN
688 adap->algo = &i2c_dw_algo;
689 adap->dev.parent = dev->dev;
690 i2c_set_adapdata(adap, dev);
691
41c80b8a
HG
692 if (dev->pm_disabled) {
693 dev_pm_syscore_device(dev->dev, true);
694 irq_flags = IRQF_NO_SUSPEND;
695 } else {
696 irq_flags = IRQF_SHARED | IRQF_COND_SUSPEND;
697 }
698
d80d1341 699 i2c_dw_disable_int(dev);
e393f674
LO
700 ret = devm_request_irq(dev->dev, dev->irq, i2c_dw_isr, irq_flags,
701 dev_name(dev->dev), dev);
702 if (ret) {
d80d1341 703 dev_err(dev->dev, "failure requesting irq %i: %d\n",
e393f674
LO
704 dev->irq, ret);
705 return ret;
d80d1341
JN
706 }
707
ca382f5b
TS
708 ret = i2c_dw_init_recovery_info(dev);
709 if (ret)
710 return ret;
711
cd998ded
JN
712 /*
713 * Increment PM usage count during adapter registration in order to
714 * avoid possible spurious runtime suspend when adapter device is
715 * registered to the device core and immediate resume in case bus has
716 * registered I2C slaves that do I2C transfers in their probe.
717 */
718 pm_runtime_get_noresume(dev->dev);
e393f674
LO
719 ret = i2c_add_numbered_adapter(adap);
720 if (ret)
721 dev_err(dev->dev, "failure adding adapter: %d\n", ret);
cd998ded 722 pm_runtime_put_noidle(dev->dev);
d80d1341 723
e393f674 724 return ret;
d80d1341
JN
725}
726EXPORT_SYMBOL_GPL(i2c_dw_probe);
727
90312351 728MODULE_DESCRIPTION("Synopsys DesignWare I2C bus master adapter");
9dd3162d 729MODULE_LICENSE("GPL");