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drivers/i2c/busses: don't check resource with devm_ioremap_resource
[deliverable/linux.git] / drivers / i2c / busses / i2c-davinci.c
1 /*
2 * TI DAVINCI I2C adapter driver.
3 *
4 * Copyright (C) 2006 Texas Instruments.
5 * Copyright (C) 2007 MontaVista Software Inc.
6 *
7 * Updated by Vinod & Sudhakar Feb 2005
8 *
9 * ----------------------------------------------------------------------------
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 of the License, or
14 * (at your option) any later version.
15 *
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
20 *
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 * ----------------------------------------------------------------------------
25 *
26 */
27 #include <linux/kernel.h>
28 #include <linux/module.h>
29 #include <linux/delay.h>
30 #include <linux/i2c.h>
31 #include <linux/clk.h>
32 #include <linux/errno.h>
33 #include <linux/sched.h>
34 #include <linux/err.h>
35 #include <linux/interrupt.h>
36 #include <linux/platform_device.h>
37 #include <linux/io.h>
38 #include <linux/slab.h>
39 #include <linux/cpufreq.h>
40 #include <linux/gpio.h>
41 #include <linux/of_i2c.h>
42 #include <linux/of_device.h>
43
44 #include <mach/hardware.h>
45 #include <linux/platform_data/i2c-davinci.h>
46
47 /* ----- global defines ----------------------------------------------- */
48
49 #define DAVINCI_I2C_TIMEOUT (1*HZ)
50 #define DAVINCI_I2C_MAX_TRIES 2
51 #define I2C_DAVINCI_INTR_ALL (DAVINCI_I2C_IMR_AAS | \
52 DAVINCI_I2C_IMR_SCD | \
53 DAVINCI_I2C_IMR_ARDY | \
54 DAVINCI_I2C_IMR_NACK | \
55 DAVINCI_I2C_IMR_AL)
56
57 #define DAVINCI_I2C_OAR_REG 0x00
58 #define DAVINCI_I2C_IMR_REG 0x04
59 #define DAVINCI_I2C_STR_REG 0x08
60 #define DAVINCI_I2C_CLKL_REG 0x0c
61 #define DAVINCI_I2C_CLKH_REG 0x10
62 #define DAVINCI_I2C_CNT_REG 0x14
63 #define DAVINCI_I2C_DRR_REG 0x18
64 #define DAVINCI_I2C_SAR_REG 0x1c
65 #define DAVINCI_I2C_DXR_REG 0x20
66 #define DAVINCI_I2C_MDR_REG 0x24
67 #define DAVINCI_I2C_IVR_REG 0x28
68 #define DAVINCI_I2C_EMDR_REG 0x2c
69 #define DAVINCI_I2C_PSC_REG 0x30
70
71 #define DAVINCI_I2C_IVR_AAS 0x07
72 #define DAVINCI_I2C_IVR_SCD 0x06
73 #define DAVINCI_I2C_IVR_XRDY 0x05
74 #define DAVINCI_I2C_IVR_RDR 0x04
75 #define DAVINCI_I2C_IVR_ARDY 0x03
76 #define DAVINCI_I2C_IVR_NACK 0x02
77 #define DAVINCI_I2C_IVR_AL 0x01
78
79 #define DAVINCI_I2C_STR_BB BIT(12)
80 #define DAVINCI_I2C_STR_RSFULL BIT(11)
81 #define DAVINCI_I2C_STR_SCD BIT(5)
82 #define DAVINCI_I2C_STR_ARDY BIT(2)
83 #define DAVINCI_I2C_STR_NACK BIT(1)
84 #define DAVINCI_I2C_STR_AL BIT(0)
85
86 #define DAVINCI_I2C_MDR_NACK BIT(15)
87 #define DAVINCI_I2C_MDR_STT BIT(13)
88 #define DAVINCI_I2C_MDR_STP BIT(11)
89 #define DAVINCI_I2C_MDR_MST BIT(10)
90 #define DAVINCI_I2C_MDR_TRX BIT(9)
91 #define DAVINCI_I2C_MDR_XA BIT(8)
92 #define DAVINCI_I2C_MDR_RM BIT(7)
93 #define DAVINCI_I2C_MDR_IRS BIT(5)
94
95 #define DAVINCI_I2C_IMR_AAS BIT(6)
96 #define DAVINCI_I2C_IMR_SCD BIT(5)
97 #define DAVINCI_I2C_IMR_XRDY BIT(4)
98 #define DAVINCI_I2C_IMR_RRDY BIT(3)
99 #define DAVINCI_I2C_IMR_ARDY BIT(2)
100 #define DAVINCI_I2C_IMR_NACK BIT(1)
101 #define DAVINCI_I2C_IMR_AL BIT(0)
102
103 struct davinci_i2c_dev {
104 struct device *dev;
105 void __iomem *base;
106 struct completion cmd_complete;
107 struct clk *clk;
108 int cmd_err;
109 u8 *buf;
110 size_t buf_len;
111 int irq;
112 int stop;
113 u8 terminate;
114 struct i2c_adapter adapter;
115 #ifdef CONFIG_CPU_FREQ
116 struct completion xfr_complete;
117 struct notifier_block freq_transition;
118 #endif
119 struct davinci_i2c_platform_data *pdata;
120 };
121
122 /* default platform data to use if not supplied in the platform_device */
123 static struct davinci_i2c_platform_data davinci_i2c_platform_data_default = {
124 .bus_freq = 100,
125 .bus_delay = 0,
126 };
127
128 static inline void davinci_i2c_write_reg(struct davinci_i2c_dev *i2c_dev,
129 int reg, u16 val)
130 {
131 __raw_writew(val, i2c_dev->base + reg);
132 }
133
134 static inline u16 davinci_i2c_read_reg(struct davinci_i2c_dev *i2c_dev, int reg)
135 {
136 return __raw_readw(i2c_dev->base + reg);
137 }
138
139 /* Generate a pulse on the i2c clock pin. */
140 static void davinci_i2c_clock_pulse(unsigned int scl_pin)
141 {
142 u16 i;
143
144 if (scl_pin) {
145 /* Send high and low on the SCL line */
146 for (i = 0; i < 9; i++) {
147 gpio_set_value(scl_pin, 0);
148 udelay(20);
149 gpio_set_value(scl_pin, 1);
150 udelay(20);
151 }
152 }
153 }
154
155 /* This routine does i2c bus recovery as specified in the
156 * i2c protocol Rev. 03 section 3.16 titled "Bus clear"
157 */
158 static void davinci_i2c_recover_bus(struct davinci_i2c_dev *dev)
159 {
160 u32 flag = 0;
161 struct davinci_i2c_platform_data *pdata = dev->pdata;
162
163 dev_err(dev->dev, "initiating i2c bus recovery\n");
164 /* Send NACK to the slave */
165 flag = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG);
166 flag |= DAVINCI_I2C_MDR_NACK;
167 /* write the data into mode register */
168 davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, flag);
169 davinci_i2c_clock_pulse(pdata->scl_pin);
170 /* Send STOP */
171 flag = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG);
172 flag |= DAVINCI_I2C_MDR_STP;
173 davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, flag);
174 }
175
176 static inline void davinci_i2c_reset_ctrl(struct davinci_i2c_dev *i2c_dev,
177 int val)
178 {
179 u16 w;
180
181 w = davinci_i2c_read_reg(i2c_dev, DAVINCI_I2C_MDR_REG);
182 if (!val) /* put I2C into reset */
183 w &= ~DAVINCI_I2C_MDR_IRS;
184 else /* take I2C out of reset */
185 w |= DAVINCI_I2C_MDR_IRS;
186
187 davinci_i2c_write_reg(i2c_dev, DAVINCI_I2C_MDR_REG, w);
188 }
189
190 static void i2c_davinci_calc_clk_dividers(struct davinci_i2c_dev *dev)
191 {
192 struct davinci_i2c_platform_data *pdata = dev->pdata;
193 u16 psc;
194 u32 clk;
195 u32 d;
196 u32 clkh;
197 u32 clkl;
198 u32 input_clock = clk_get_rate(dev->clk);
199
200 /* NOTE: I2C Clock divider programming info
201 * As per I2C specs the following formulas provide prescaler
202 * and low/high divider values
203 * input clk --> PSC Div -----------> ICCL/H Div --> output clock
204 * module clk
205 *
206 * output clk = module clk / (PSC + 1) [ (ICCL + d) + (ICCH + d) ]
207 *
208 * Thus,
209 * (ICCL + ICCH) = clk = (input clk / ((psc +1) * output clk)) - 2d;
210 *
211 * where if PSC == 0, d = 7,
212 * if PSC == 1, d = 6
213 * if PSC > 1 , d = 5
214 */
215
216 /* get minimum of 7 MHz clock, but max of 12 MHz */
217 psc = (input_clock / 7000000) - 1;
218 if ((input_clock / (psc + 1)) > 12000000)
219 psc++; /* better to run under spec than over */
220 d = (psc >= 2) ? 5 : 7 - psc;
221
222 clk = ((input_clock / (psc + 1)) / (pdata->bus_freq * 1000)) - (d << 1);
223 clkh = clk >> 1;
224 clkl = clk - clkh;
225
226 davinci_i2c_write_reg(dev, DAVINCI_I2C_PSC_REG, psc);
227 davinci_i2c_write_reg(dev, DAVINCI_I2C_CLKH_REG, clkh);
228 davinci_i2c_write_reg(dev, DAVINCI_I2C_CLKL_REG, clkl);
229
230 dev_dbg(dev->dev, "input_clock = %d, CLK = %d\n", input_clock, clk);
231 }
232
233 /*
234 * This function configures I2C and brings I2C out of reset.
235 * This function is called during I2C init function. This function
236 * also gets called if I2C encounters any errors.
237 */
238 static int i2c_davinci_init(struct davinci_i2c_dev *dev)
239 {
240 struct davinci_i2c_platform_data *pdata = dev->pdata;
241
242 /* put I2C into reset */
243 davinci_i2c_reset_ctrl(dev, 0);
244
245 /* compute clock dividers */
246 i2c_davinci_calc_clk_dividers(dev);
247
248 /* Respond at reserved "SMBus Host" slave address" (and zero);
249 * we seem to have no option to not respond...
250 */
251 davinci_i2c_write_reg(dev, DAVINCI_I2C_OAR_REG, 0x08);
252
253 dev_dbg(dev->dev, "PSC = %d\n",
254 davinci_i2c_read_reg(dev, DAVINCI_I2C_PSC_REG));
255 dev_dbg(dev->dev, "CLKL = %d\n",
256 davinci_i2c_read_reg(dev, DAVINCI_I2C_CLKL_REG));
257 dev_dbg(dev->dev, "CLKH = %d\n",
258 davinci_i2c_read_reg(dev, DAVINCI_I2C_CLKH_REG));
259 dev_dbg(dev->dev, "bus_freq = %dkHz, bus_delay = %d\n",
260 pdata->bus_freq, pdata->bus_delay);
261
262
263 /* Take the I2C module out of reset: */
264 davinci_i2c_reset_ctrl(dev, 1);
265
266 /* Enable interrupts */
267 davinci_i2c_write_reg(dev, DAVINCI_I2C_IMR_REG, I2C_DAVINCI_INTR_ALL);
268
269 return 0;
270 }
271
272 /*
273 * Waiting for bus not busy
274 */
275 static int i2c_davinci_wait_bus_not_busy(struct davinci_i2c_dev *dev,
276 char allow_sleep)
277 {
278 unsigned long timeout;
279 static u16 to_cnt;
280
281 timeout = jiffies + dev->adapter.timeout;
282 while (davinci_i2c_read_reg(dev, DAVINCI_I2C_STR_REG)
283 & DAVINCI_I2C_STR_BB) {
284 if (to_cnt <= DAVINCI_I2C_MAX_TRIES) {
285 if (time_after(jiffies, timeout)) {
286 dev_warn(dev->dev,
287 "timeout waiting for bus ready\n");
288 to_cnt++;
289 return -ETIMEDOUT;
290 } else {
291 to_cnt = 0;
292 davinci_i2c_recover_bus(dev);
293 i2c_davinci_init(dev);
294 }
295 }
296 if (allow_sleep)
297 schedule_timeout(1);
298 }
299
300 return 0;
301 }
302
303 /*
304 * Low level master read/write transaction. This function is called
305 * from i2c_davinci_xfer.
306 */
307 static int
308 i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop)
309 {
310 struct davinci_i2c_dev *dev = i2c_get_adapdata(adap);
311 struct davinci_i2c_platform_data *pdata = dev->pdata;
312 u32 flag;
313 u16 w;
314 int r;
315
316 /* Introduce a delay, required for some boards (e.g Davinci EVM) */
317 if (pdata->bus_delay)
318 udelay(pdata->bus_delay);
319
320 /* set the slave address */
321 davinci_i2c_write_reg(dev, DAVINCI_I2C_SAR_REG, msg->addr);
322
323 dev->buf = msg->buf;
324 dev->buf_len = msg->len;
325 dev->stop = stop;
326
327 davinci_i2c_write_reg(dev, DAVINCI_I2C_CNT_REG, dev->buf_len);
328
329 INIT_COMPLETION(dev->cmd_complete);
330 dev->cmd_err = 0;
331
332 /* Take I2C out of reset and configure it as master */
333 flag = DAVINCI_I2C_MDR_IRS | DAVINCI_I2C_MDR_MST;
334
335 /* if the slave address is ten bit address, enable XA bit */
336 if (msg->flags & I2C_M_TEN)
337 flag |= DAVINCI_I2C_MDR_XA;
338 if (!(msg->flags & I2C_M_RD))
339 flag |= DAVINCI_I2C_MDR_TRX;
340 if (msg->len == 0)
341 flag |= DAVINCI_I2C_MDR_RM;
342
343 /* Enable receive or transmit interrupts */
344 w = davinci_i2c_read_reg(dev, DAVINCI_I2C_IMR_REG);
345 if (msg->flags & I2C_M_RD)
346 w |= DAVINCI_I2C_IMR_RRDY;
347 else
348 w |= DAVINCI_I2C_IMR_XRDY;
349 davinci_i2c_write_reg(dev, DAVINCI_I2C_IMR_REG, w);
350
351 dev->terminate = 0;
352
353 /*
354 * Write mode register first as needed for correct behaviour
355 * on OMAP-L138, but don't set STT yet to avoid a race with XRDY
356 * occurring before we have loaded DXR
357 */
358 davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, flag);
359
360 /*
361 * First byte should be set here, not after interrupt,
362 * because transmit-data-ready interrupt can come before
363 * NACK-interrupt during sending of previous message and
364 * ICDXR may have wrong data
365 * It also saves us one interrupt, slightly faster
366 */
367 if ((!(msg->flags & I2C_M_RD)) && dev->buf_len) {
368 davinci_i2c_write_reg(dev, DAVINCI_I2C_DXR_REG, *dev->buf++);
369 dev->buf_len--;
370 }
371
372 /* Set STT to begin transmit now DXR is loaded */
373 flag |= DAVINCI_I2C_MDR_STT;
374 if (stop && msg->len != 0)
375 flag |= DAVINCI_I2C_MDR_STP;
376 davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, flag);
377
378 r = wait_for_completion_interruptible_timeout(&dev->cmd_complete,
379 dev->adapter.timeout);
380 if (r == 0) {
381 dev_err(dev->dev, "controller timed out\n");
382 davinci_i2c_recover_bus(dev);
383 i2c_davinci_init(dev);
384 dev->buf_len = 0;
385 return -ETIMEDOUT;
386 }
387 if (dev->buf_len) {
388 /* This should be 0 if all bytes were transferred
389 * or dev->cmd_err denotes an error.
390 * A signal may have aborted the transfer.
391 */
392 if (r >= 0) {
393 dev_err(dev->dev, "abnormal termination buf_len=%i\n",
394 dev->buf_len);
395 r = -EREMOTEIO;
396 }
397 dev->terminate = 1;
398 wmb();
399 dev->buf_len = 0;
400 }
401 if (r < 0)
402 return r;
403
404 /* no error */
405 if (likely(!dev->cmd_err))
406 return msg->len;
407
408 /* We have an error */
409 if (dev->cmd_err & DAVINCI_I2C_STR_AL) {
410 i2c_davinci_init(dev);
411 return -EIO;
412 }
413
414 if (dev->cmd_err & DAVINCI_I2C_STR_NACK) {
415 if (msg->flags & I2C_M_IGNORE_NAK)
416 return msg->len;
417 if (stop) {
418 w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG);
419 w |= DAVINCI_I2C_MDR_STP;
420 davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w);
421 }
422 return -EREMOTEIO;
423 }
424 return -EIO;
425 }
426
427 /*
428 * Prepare controller for a transaction and call i2c_davinci_xfer_msg
429 */
430 static int
431 i2c_davinci_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
432 {
433 struct davinci_i2c_dev *dev = i2c_get_adapdata(adap);
434 int i;
435 int ret;
436
437 dev_dbg(dev->dev, "%s: msgs: %d\n", __func__, num);
438
439 ret = i2c_davinci_wait_bus_not_busy(dev, 1);
440 if (ret < 0) {
441 dev_warn(dev->dev, "timeout waiting for bus ready\n");
442 return ret;
443 }
444
445 for (i = 0; i < num; i++) {
446 ret = i2c_davinci_xfer_msg(adap, &msgs[i], (i == (num - 1)));
447 dev_dbg(dev->dev, "%s [%d/%d] ret: %d\n", __func__, i + 1, num,
448 ret);
449 if (ret < 0)
450 return ret;
451 }
452
453 #ifdef CONFIG_CPU_FREQ
454 complete(&dev->xfr_complete);
455 #endif
456
457 return num;
458 }
459
460 static u32 i2c_davinci_func(struct i2c_adapter *adap)
461 {
462 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
463 }
464
465 static void terminate_read(struct davinci_i2c_dev *dev)
466 {
467 u16 w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG);
468 w |= DAVINCI_I2C_MDR_NACK;
469 davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w);
470
471 /* Throw away data */
472 davinci_i2c_read_reg(dev, DAVINCI_I2C_DRR_REG);
473 if (!dev->terminate)
474 dev_err(dev->dev, "RDR IRQ while no data requested\n");
475 }
476 static void terminate_write(struct davinci_i2c_dev *dev)
477 {
478 u16 w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG);
479 w |= DAVINCI_I2C_MDR_RM | DAVINCI_I2C_MDR_STP;
480 davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w);
481
482 if (!dev->terminate)
483 dev_dbg(dev->dev, "TDR IRQ while no data to send\n");
484 }
485
486 /*
487 * Interrupt service routine. This gets called whenever an I2C interrupt
488 * occurs.
489 */
490 static irqreturn_t i2c_davinci_isr(int this_irq, void *dev_id)
491 {
492 struct davinci_i2c_dev *dev = dev_id;
493 u32 stat;
494 int count = 0;
495 u16 w;
496
497 while ((stat = davinci_i2c_read_reg(dev, DAVINCI_I2C_IVR_REG))) {
498 dev_dbg(dev->dev, "%s: stat=0x%x\n", __func__, stat);
499 if (count++ == 100) {
500 dev_warn(dev->dev, "Too much work in one IRQ\n");
501 break;
502 }
503
504 switch (stat) {
505 case DAVINCI_I2C_IVR_AL:
506 /* Arbitration lost, must retry */
507 dev->cmd_err |= DAVINCI_I2C_STR_AL;
508 dev->buf_len = 0;
509 complete(&dev->cmd_complete);
510 break;
511
512 case DAVINCI_I2C_IVR_NACK:
513 dev->cmd_err |= DAVINCI_I2C_STR_NACK;
514 dev->buf_len = 0;
515 complete(&dev->cmd_complete);
516 break;
517
518 case DAVINCI_I2C_IVR_ARDY:
519 davinci_i2c_write_reg(dev,
520 DAVINCI_I2C_STR_REG, DAVINCI_I2C_STR_ARDY);
521 if (((dev->buf_len == 0) && (dev->stop != 0)) ||
522 (dev->cmd_err & DAVINCI_I2C_STR_NACK)) {
523 w = davinci_i2c_read_reg(dev,
524 DAVINCI_I2C_MDR_REG);
525 w |= DAVINCI_I2C_MDR_STP;
526 davinci_i2c_write_reg(dev,
527 DAVINCI_I2C_MDR_REG, w);
528 }
529 complete(&dev->cmd_complete);
530 break;
531
532 case DAVINCI_I2C_IVR_RDR:
533 if (dev->buf_len) {
534 *dev->buf++ =
535 davinci_i2c_read_reg(dev,
536 DAVINCI_I2C_DRR_REG);
537 dev->buf_len--;
538 if (dev->buf_len)
539 continue;
540
541 davinci_i2c_write_reg(dev,
542 DAVINCI_I2C_STR_REG,
543 DAVINCI_I2C_IMR_RRDY);
544 } else {
545 /* signal can terminate transfer */
546 terminate_read(dev);
547 }
548 break;
549
550 case DAVINCI_I2C_IVR_XRDY:
551 if (dev->buf_len) {
552 davinci_i2c_write_reg(dev, DAVINCI_I2C_DXR_REG,
553 *dev->buf++);
554 dev->buf_len--;
555 if (dev->buf_len)
556 continue;
557
558 w = davinci_i2c_read_reg(dev,
559 DAVINCI_I2C_IMR_REG);
560 w &= ~DAVINCI_I2C_IMR_XRDY;
561 davinci_i2c_write_reg(dev,
562 DAVINCI_I2C_IMR_REG,
563 w);
564 } else {
565 /* signal can terminate transfer */
566 terminate_write(dev);
567 }
568 break;
569
570 case DAVINCI_I2C_IVR_SCD:
571 davinci_i2c_write_reg(dev,
572 DAVINCI_I2C_STR_REG, DAVINCI_I2C_STR_SCD);
573 complete(&dev->cmd_complete);
574 break;
575
576 case DAVINCI_I2C_IVR_AAS:
577 dev_dbg(dev->dev, "Address as slave interrupt\n");
578 break;
579
580 default:
581 dev_warn(dev->dev, "Unrecognized irq stat %d\n", stat);
582 break;
583 }
584 }
585
586 return count ? IRQ_HANDLED : IRQ_NONE;
587 }
588
589 #ifdef CONFIG_CPU_FREQ
590 static int i2c_davinci_cpufreq_transition(struct notifier_block *nb,
591 unsigned long val, void *data)
592 {
593 struct davinci_i2c_dev *dev;
594
595 dev = container_of(nb, struct davinci_i2c_dev, freq_transition);
596 if (val == CPUFREQ_PRECHANGE) {
597 wait_for_completion(&dev->xfr_complete);
598 davinci_i2c_reset_ctrl(dev, 0);
599 } else if (val == CPUFREQ_POSTCHANGE) {
600 i2c_davinci_calc_clk_dividers(dev);
601 davinci_i2c_reset_ctrl(dev, 1);
602 }
603
604 return 0;
605 }
606
607 static inline int i2c_davinci_cpufreq_register(struct davinci_i2c_dev *dev)
608 {
609 dev->freq_transition.notifier_call = i2c_davinci_cpufreq_transition;
610
611 return cpufreq_register_notifier(&dev->freq_transition,
612 CPUFREQ_TRANSITION_NOTIFIER);
613 }
614
615 static inline void i2c_davinci_cpufreq_deregister(struct davinci_i2c_dev *dev)
616 {
617 cpufreq_unregister_notifier(&dev->freq_transition,
618 CPUFREQ_TRANSITION_NOTIFIER);
619 }
620 #else
621 static inline int i2c_davinci_cpufreq_register(struct davinci_i2c_dev *dev)
622 {
623 return 0;
624 }
625
626 static inline void i2c_davinci_cpufreq_deregister(struct davinci_i2c_dev *dev)
627 {
628 }
629 #endif
630
631 static struct i2c_algorithm i2c_davinci_algo = {
632 .master_xfer = i2c_davinci_xfer,
633 .functionality = i2c_davinci_func,
634 };
635
636 static const struct of_device_id davinci_i2c_of_match[] = {
637 {.compatible = "ti,davinci-i2c", },
638 {},
639 };
640 MODULE_DEVICE_TABLE(of, davinci_i2c_of_match);
641
642 static int davinci_i2c_probe(struct platform_device *pdev)
643 {
644 struct davinci_i2c_dev *dev;
645 struct i2c_adapter *adap;
646 struct resource *mem, *irq;
647 int r;
648
649 irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
650 if (!irq) {
651 dev_err(&pdev->dev, "no irq resource?\n");
652 return -ENODEV;
653 }
654
655 dev = devm_kzalloc(&pdev->dev, sizeof(struct davinci_i2c_dev),
656 GFP_KERNEL);
657 if (!dev) {
658 dev_err(&pdev->dev, "Memory allocation failed\n");
659 return -ENOMEM;
660 }
661
662 init_completion(&dev->cmd_complete);
663 #ifdef CONFIG_CPU_FREQ
664 init_completion(&dev->xfr_complete);
665 #endif
666 dev->dev = &pdev->dev;
667 dev->irq = irq->start;
668 dev->pdata = dev->dev->platform_data;
669 platform_set_drvdata(pdev, dev);
670
671 if (!dev->pdata && pdev->dev.of_node) {
672 u32 prop;
673
674 dev->pdata = devm_kzalloc(&pdev->dev,
675 sizeof(struct davinci_i2c_platform_data), GFP_KERNEL);
676 if (!dev->pdata)
677 return -ENOMEM;
678
679 memcpy(dev->pdata, &davinci_i2c_platform_data_default,
680 sizeof(struct davinci_i2c_platform_data));
681 if (!of_property_read_u32(pdev->dev.of_node, "clock-frequency",
682 &prop))
683 dev->pdata->bus_freq = prop / 1000;
684 } else if (!dev->pdata) {
685 dev->pdata = &davinci_i2c_platform_data_default;
686 }
687
688 dev->clk = devm_clk_get(&pdev->dev, NULL);
689 if (IS_ERR(dev->clk))
690 return -ENODEV;
691 clk_prepare_enable(dev->clk);
692
693 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
694 dev->base = devm_ioremap_resource(&pdev->dev, mem);
695 if (IS_ERR(dev->base)) {
696 r = PTR_ERR(dev->base);
697 goto err_unuse_clocks;
698 }
699
700 i2c_davinci_init(dev);
701
702 r = devm_request_irq(&pdev->dev, dev->irq, i2c_davinci_isr, 0,
703 pdev->name, dev);
704 if (r) {
705 dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq);
706 goto err_unuse_clocks;
707 }
708
709 r = i2c_davinci_cpufreq_register(dev);
710 if (r) {
711 dev_err(&pdev->dev, "failed to register cpufreq\n");
712 goto err_unuse_clocks;
713 }
714
715 adap = &dev->adapter;
716 i2c_set_adapdata(adap, dev);
717 adap->owner = THIS_MODULE;
718 adap->class = I2C_CLASS_HWMON;
719 strlcpy(adap->name, "DaVinci I2C adapter", sizeof(adap->name));
720 adap->algo = &i2c_davinci_algo;
721 adap->dev.parent = &pdev->dev;
722 adap->timeout = DAVINCI_I2C_TIMEOUT;
723 adap->dev.of_node = pdev->dev.of_node;
724
725 adap->nr = pdev->id;
726 r = i2c_add_numbered_adapter(adap);
727 if (r) {
728 dev_err(&pdev->dev, "failure adding adapter\n");
729 goto err_unuse_clocks;
730 }
731 of_i2c_register_devices(adap);
732
733 return 0;
734
735 err_unuse_clocks:
736 clk_disable_unprepare(dev->clk);
737 dev->clk = NULL;
738 return r;
739 }
740
741 static int davinci_i2c_remove(struct platform_device *pdev)
742 {
743 struct davinci_i2c_dev *dev = platform_get_drvdata(pdev);
744
745 i2c_davinci_cpufreq_deregister(dev);
746
747 i2c_del_adapter(&dev->adapter);
748
749 clk_disable_unprepare(dev->clk);
750 dev->clk = NULL;
751
752 davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, 0);
753
754 return 0;
755 }
756
757 #ifdef CONFIG_PM
758 static int davinci_i2c_suspend(struct device *dev)
759 {
760 struct platform_device *pdev = to_platform_device(dev);
761 struct davinci_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
762
763 /* put I2C into reset */
764 davinci_i2c_reset_ctrl(i2c_dev, 0);
765 clk_disable_unprepare(i2c_dev->clk);
766
767 return 0;
768 }
769
770 static int davinci_i2c_resume(struct device *dev)
771 {
772 struct platform_device *pdev = to_platform_device(dev);
773 struct davinci_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
774
775 clk_prepare_enable(i2c_dev->clk);
776 /* take I2C out of reset */
777 davinci_i2c_reset_ctrl(i2c_dev, 1);
778
779 return 0;
780 }
781
782 static const struct dev_pm_ops davinci_i2c_pm = {
783 .suspend = davinci_i2c_suspend,
784 .resume = davinci_i2c_resume,
785 };
786
787 #define davinci_i2c_pm_ops (&davinci_i2c_pm)
788 #else
789 #define davinci_i2c_pm_ops NULL
790 #endif
791
792 /* work with hotplug and coldplug */
793 MODULE_ALIAS("platform:i2c_davinci");
794
795 static struct platform_driver davinci_i2c_driver = {
796 .probe = davinci_i2c_probe,
797 .remove = davinci_i2c_remove,
798 .driver = {
799 .name = "i2c_davinci",
800 .owner = THIS_MODULE,
801 .pm = davinci_i2c_pm_ops,
802 .of_match_table = of_match_ptr(davinci_i2c_of_match),
803 },
804 };
805
806 /* I2C may be needed to bring up other drivers */
807 static int __init davinci_i2c_init_driver(void)
808 {
809 return platform_driver_register(&davinci_i2c_driver);
810 }
811 subsys_initcall(davinci_i2c_init_driver);
812
813 static void __exit davinci_i2c_exit_driver(void)
814 {
815 platform_driver_unregister(&davinci_i2c_driver);
816 }
817 module_exit(davinci_i2c_exit_driver);
818
819 MODULE_AUTHOR("Texas Instruments India");
820 MODULE_DESCRIPTION("TI DaVinci I2C bus adapter");
821 MODULE_LICENSE("GPL");
Linux kernel - Deliverables
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