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The discovered bit in PGCCSR register indicates if the device has been
[linux-2.6/next.git] / drivers / i2c / busses / i2c-davinci.c
bloba76d85fa3ad781d15a90f73875a1c857703d14a8
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
42 #include <mach/hardware.h>
43 #include <mach/i2c.h>
44
45 /* ----- global defines ----------------------------------------------- */
46
47 #define DAVINCI_I2C_TIMEOUT (1*HZ)
48 #define DAVINCI_I2C_MAX_TRIES 2
49 #define I2C_DAVINCI_INTR_ALL (DAVINCI_I2C_IMR_AAS | \
50 DAVINCI_I2C_IMR_SCD | \
51 DAVINCI_I2C_IMR_ARDY | \
52 DAVINCI_I2C_IMR_NACK | \
53 DAVINCI_I2C_IMR_AL)
54
55 #define DAVINCI_I2C_OAR_REG 0x00
56 #define DAVINCI_I2C_IMR_REG 0x04
57 #define DAVINCI_I2C_STR_REG 0x08
58 #define DAVINCI_I2C_CLKL_REG 0x0c
59 #define DAVINCI_I2C_CLKH_REG 0x10
60 #define DAVINCI_I2C_CNT_REG 0x14
61 #define DAVINCI_I2C_DRR_REG 0x18
62 #define DAVINCI_I2C_SAR_REG 0x1c
63 #define DAVINCI_I2C_DXR_REG 0x20
64 #define DAVINCI_I2C_MDR_REG 0x24
65 #define DAVINCI_I2C_IVR_REG 0x28
66 #define DAVINCI_I2C_EMDR_REG 0x2c
67 #define DAVINCI_I2C_PSC_REG 0x30
68
69 #define DAVINCI_I2C_IVR_AAS 0x07
70 #define DAVINCI_I2C_IVR_SCD 0x06
71 #define DAVINCI_I2C_IVR_XRDY 0x05
72 #define DAVINCI_I2C_IVR_RDR 0x04
73 #define DAVINCI_I2C_IVR_ARDY 0x03
74 #define DAVINCI_I2C_IVR_NACK 0x02
75 #define DAVINCI_I2C_IVR_AL 0x01
76
77 #define DAVINCI_I2C_STR_BB BIT(12)
78 #define DAVINCI_I2C_STR_RSFULL BIT(11)
79 #define DAVINCI_I2C_STR_SCD BIT(5)
80 #define DAVINCI_I2C_STR_ARDY BIT(2)
81 #define DAVINCI_I2C_STR_NACK BIT(1)
82 #define DAVINCI_I2C_STR_AL BIT(0)
83
84 #define DAVINCI_I2C_MDR_NACK BIT(15)
85 #define DAVINCI_I2C_MDR_STT BIT(13)
86 #define DAVINCI_I2C_MDR_STP BIT(11)
87 #define DAVINCI_I2C_MDR_MST BIT(10)
88 #define DAVINCI_I2C_MDR_TRX BIT(9)
89 #define DAVINCI_I2C_MDR_XA BIT(8)
90 #define DAVINCI_I2C_MDR_RM BIT(7)
91 #define DAVINCI_I2C_MDR_IRS BIT(5)
92
93 #define DAVINCI_I2C_IMR_AAS BIT(6)
94 #define DAVINCI_I2C_IMR_SCD BIT(5)
95 #define DAVINCI_I2C_IMR_XRDY BIT(4)
96 #define DAVINCI_I2C_IMR_RRDY BIT(3)
97 #define DAVINCI_I2C_IMR_ARDY BIT(2)
98 #define DAVINCI_I2C_IMR_NACK BIT(1)
99 #define DAVINCI_I2C_IMR_AL BIT(0)
100
101 struct davinci_i2c_dev {
102 struct device *dev;
103 void __iomem *base;
104 struct completion cmd_complete;
105 struct clk *clk;
106 int cmd_err;
107 u8 *buf;
108 size_t buf_len;
109 int irq;
110 int stop;
111 u8 terminate;
112 struct i2c_adapter adapter;
113 #ifdef CONFIG_CPU_FREQ
114 struct completion xfr_complete;
115 struct notifier_block freq_transition;
116 #endif
117 };
118
119 /* default platform data to use if not supplied in the platform_device */
120 static struct davinci_i2c_platform_data davinci_i2c_platform_data_default = {
121 .bus_freq = 100,
122 .bus_delay = 0,
123 };
124
125 static inline void davinci_i2c_write_reg(struct davinci_i2c_dev *i2c_dev,
126 int reg, u16 val)
127 {
128 __raw_writew(val, i2c_dev->base + reg);
129 }
130
131 static inline u16 davinci_i2c_read_reg(struct davinci_i2c_dev *i2c_dev, int reg)
132 {
133 return __raw_readw(i2c_dev->base + reg);
134 }
135
136 /* Generate a pulse on the i2c clock pin. */
137 static void generic_i2c_clock_pulse(unsigned int scl_pin)
138 {
139 u16 i;
140
141 if (scl_pin) {
142 /* Send high and low on the SCL line */
143 for (i = 0; i < 9; i++) {
144 gpio_set_value(scl_pin, 0);
145 udelay(20);
146 gpio_set_value(scl_pin, 1);
147 udelay(20);
148 }
149 }
150 }
151
152 /* This routine does i2c bus recovery as specified in the
153 * i2c protocol Rev. 03 section 3.16 titled "Bus clear"
154 */
155 static void i2c_recover_bus(struct davinci_i2c_dev *dev)
156 {
157 u32 flag = 0;
158 struct davinci_i2c_platform_data *pdata = dev->dev->platform_data;
159
160 dev_err(dev->dev, "initiating i2c bus recovery\n");
161 /* Send NACK to the slave */
162 flag = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG);
163 flag |= DAVINCI_I2C_MDR_NACK;
164 /* write the data into mode register */
165 davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, flag);
166 if (pdata)
167 generic_i2c_clock_pulse(pdata->scl_pin);
168 /* Send STOP */
169 flag = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG);
170 flag |= DAVINCI_I2C_MDR_STP;
171 davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, flag);
172 }
173
174 static inline void davinci_i2c_reset_ctrl(struct davinci_i2c_dev *i2c_dev,
175 int val)
176 {
177 u16 w;
178
179 w = davinci_i2c_read_reg(i2c_dev, DAVINCI_I2C_MDR_REG);
180 if (!val) /* put I2C into reset */
181 w &= ~DAVINCI_I2C_MDR_IRS;
182 else /* take I2C out of reset */
183 w |= DAVINCI_I2C_MDR_IRS;
184
185 davinci_i2c_write_reg(i2c_dev, DAVINCI_I2C_MDR_REG, w);
186 }
187
188 static void i2c_davinci_calc_clk_dividers(struct davinci_i2c_dev *dev)
189 {
190 struct davinci_i2c_platform_data *pdata = dev->dev->platform_data;
191 u16 psc;
192 u32 clk;
193 u32 d;
194 u32 clkh;
195 u32 clkl;
196 u32 input_clock = clk_get_rate(dev->clk);
197
198 /* NOTE: I2C Clock divider programming info
199 * As per I2C specs the following formulas provide prescaler
200 * and low/high divider values
201 * input clk --> PSC Div -----------> ICCL/H Div --> output clock
202 * module clk
203 *
204 * output clk = module clk / (PSC + 1) [ (ICCL + d) + (ICCH + d) ]
205 *
206 * Thus,
207 * (ICCL + ICCH) = clk = (input clk / ((psc +1) * output clk)) - 2d;
208 *
209 * where if PSC == 0, d = 7,
210 * if PSC == 1, d = 6
211 * if PSC > 1 , d = 5
212 */
213
214 /* get minimum of 7 MHz clock, but max of 12 MHz */
215 psc = (input_clock / 7000000) - 1;
216 if ((input_clock / (psc + 1)) > 12000000)
217 psc++; /* better to run under spec than over */
218 d = (psc >= 2) ? 5 : 7 - psc;
219
220 clk = ((input_clock / (psc + 1)) / (pdata->bus_freq * 1000)) - (d << 1);
221 clkh = clk >> 1;
222 clkl = clk - clkh;
223
224 davinci_i2c_write_reg(dev, DAVINCI_I2C_PSC_REG, psc);
225 davinci_i2c_write_reg(dev, DAVINCI_I2C_CLKH_REG, clkh);
226 davinci_i2c_write_reg(dev, DAVINCI_I2C_CLKL_REG, clkl);
227
228 dev_dbg(dev->dev, "input_clock = %d, CLK = %d\n", input_clock, clk);
229 }
230
231 /*
232 * This function configures I2C and brings I2C out of reset.
233 * This function is called during I2C init function. This function
234 * also gets called if I2C encounters any errors.
235 */
236 static int i2c_davinci_init(struct davinci_i2c_dev *dev)
237 {
238 struct davinci_i2c_platform_data *pdata = dev->dev->platform_data;
239
240 if (!pdata)
241 pdata = &davinci_i2c_platform_data_default;
242
243 /* put I2C into reset */
244 davinci_i2c_reset_ctrl(dev, 0);
245
246 /* compute clock dividers */
247 i2c_davinci_calc_clk_dividers(dev);
248
249 /* Respond at reserved "SMBus Host" slave address" (and zero);
250 * we seem to have no option to not respond...
251 */
252 davinci_i2c_write_reg(dev, DAVINCI_I2C_OAR_REG, 0x08);
253
254 dev_dbg(dev->dev, "PSC = %d\n",
255 davinci_i2c_read_reg(dev, DAVINCI_I2C_PSC_REG));
256 dev_dbg(dev->dev, "CLKL = %d\n",
257 davinci_i2c_read_reg(dev, DAVINCI_I2C_CLKL_REG));
258 dev_dbg(dev->dev, "CLKH = %d\n",
259 davinci_i2c_read_reg(dev, DAVINCI_I2C_CLKH_REG));
260 dev_dbg(dev->dev, "bus_freq = %dkHz, bus_delay = %d\n",
261 pdata->bus_freq, pdata->bus_delay);
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 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->dev->platform_data;
312 u32 flag;
313 u16 w;
314 int r;
315
316 if (!pdata)
317 pdata = &davinci_i2c_platform_data_default;
318 /* Introduce a delay, required for some boards (e.g Davinci EVM) */
319 if (pdata->bus_delay)
320 udelay(pdata->bus_delay);
321
322 /* set the slave address */
323 davinci_i2c_write_reg(dev, DAVINCI_I2C_SAR_REG, msg->addr);
324
325 dev->buf = msg->buf;
326 dev->buf_len = msg->len;
327 dev->stop = stop;
328
329 davinci_i2c_write_reg(dev, DAVINCI_I2C_CNT_REG, dev->buf_len);
330
331 INIT_COMPLETION(dev->cmd_complete);
332 dev->cmd_err = 0;
333
334 /* Take I2C out of reset and configure it as master */
335 flag = DAVINCI_I2C_MDR_IRS | DAVINCI_I2C_MDR_MST;
336
337 /* if the slave address is ten bit address, enable XA bit */
338 if (msg->flags & I2C_M_TEN)
339 flag |= DAVINCI_I2C_MDR_XA;
340 if (!(msg->flags & I2C_M_RD))
341 flag |= DAVINCI_I2C_MDR_TRX;
342 if (msg->len == 0)
343 flag |= DAVINCI_I2C_MDR_RM;
344
345 /* Enable receive or transmit interrupts */
346 w = davinci_i2c_read_reg(dev, DAVINCI_I2C_IMR_REG);
347 if (msg->flags & I2C_M_RD)
348 w |= DAVINCI_I2C_IMR_RRDY;
349 else
350 w |= DAVINCI_I2C_IMR_XRDY;
351 davinci_i2c_write_reg(dev, DAVINCI_I2C_IMR_REG, w);
352
353 dev->terminate = 0;
354
355 /*
356 * Write mode register first as needed for correct behaviour
357 * on OMAP-L138, but don't set STT yet to avoid a race with XRDY
358 * occurring before we have loaded DXR
359 */
360 davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, flag);
361
362 /*
363 * First byte should be set here, not after interrupt,
364 * because transmit-data-ready interrupt can come before
365 * NACK-interrupt during sending of previous message and
366 * ICDXR may have wrong data
367 * It also saves us one interrupt, slightly faster
368 */
369 if ((!(msg->flags & I2C_M_RD)) && dev->buf_len) {
370 davinci_i2c_write_reg(dev, DAVINCI_I2C_DXR_REG, *dev->buf++);
371 dev->buf_len--;
372 }
373
374 /* Set STT to begin transmit now DXR is loaded */
375 flag |= DAVINCI_I2C_MDR_STT;
376 if (stop && msg->len != 0)
377 flag |= DAVINCI_I2C_MDR_STP;
378 davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, flag);
379
380 r = wait_for_completion_interruptible_timeout(&dev->cmd_complete,
381 dev->adapter.timeout);
382 if (r == 0) {
383 dev_err(dev->dev, "controller timed out\n");
384 i2c_recover_bus(dev);
385 i2c_davinci_init(dev);
386 dev->buf_len = 0;
387 return -ETIMEDOUT;
388 }
389 if (dev->buf_len) {
390 /* This should be 0 if all bytes were transferred
391 * or dev->cmd_err denotes an error.
392 * A signal may have aborted the transfer.
393 */
394 if (r >= 0) {
395 dev_err(dev->dev, "abnormal termination buf_len=%i\n",
396 dev->buf_len);
397 r = -EREMOTEIO;
398 }
399 dev->terminate = 1;
400 wmb();
401 dev->buf_len = 0;
402 }
403 if (r < 0)
404 return r;
405
406 /* no error */
407 if (likely(!dev->cmd_err))
408 return msg->len;
409
410 /* We have an error */
411 if (dev->cmd_err & DAVINCI_I2C_STR_AL) {
412 i2c_davinci_init(dev);
413 return -EIO;
414 }
415
416 if (dev->cmd_err & DAVINCI_I2C_STR_NACK) {
417 if (msg->flags & I2C_M_IGNORE_NAK)
418 return msg->len;
419 if (stop) {
420 w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG);
421 w |= DAVINCI_I2C_MDR_STP;
422 davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w);
423 }
424 return -EREMOTEIO;
425 }
426 return -EIO;
427 }
428
429 /*
430 * Prepare controller for a transaction and call i2c_davinci_xfer_msg
431 */
432 static int
433 i2c_davinci_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
434 {
435 struct davinci_i2c_dev *dev = i2c_get_adapdata(adap);
436 int i;
437 int ret;
438
439 dev_dbg(dev->dev, "%s: msgs: %d\n", __func__, num);
440
441 ret = i2c_davinci_wait_bus_not_busy(dev, 1);
442 if (ret < 0) {
443 dev_warn(dev->dev, "timeout waiting for bus ready\n");
444 return ret;
445 }
446
447 for (i = 0; i < num; i++) {
448 ret = i2c_davinci_xfer_msg(adap, &msgs[i], (i == (num - 1)));
449 dev_dbg(dev->dev, "%s [%d/%d] ret: %d\n", __func__, i + 1, num,
450 ret);
451 if (ret < 0)
452 return ret;
453 }
454
455 #ifdef CONFIG_CPU_FREQ
456 complete(&dev->xfr_complete);
457 #endif
458
459 return num;
460 }
461
462 static u32 i2c_davinci_func(struct i2c_adapter *adap)
463 {
464 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
465 }
466
467 static void terminate_read(struct davinci_i2c_dev *dev)
468 {
469 u16 w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG);
470 w |= DAVINCI_I2C_MDR_NACK;
471 davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w);
472
473 /* Throw away data */
474 davinci_i2c_read_reg(dev, DAVINCI_I2C_DRR_REG);
475 if (!dev->terminate)
476 dev_err(dev->dev, "RDR IRQ while no data requested\n");
477 }
478 static void terminate_write(struct davinci_i2c_dev *dev)
479 {
480 u16 w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG);
481 w |= DAVINCI_I2C_MDR_RM | DAVINCI_I2C_MDR_STP;
482 davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w);
483
484 if (!dev->terminate)
485 dev_dbg(dev->dev, "TDR IRQ while no data to send\n");
486 }
487
488 /*
489 * Interrupt service routine. This gets called whenever an I2C interrupt
490 * occurs.
491 */
492 static irqreturn_t i2c_davinci_isr(int this_irq, void *dev_id)
493 {
494 struct davinci_i2c_dev *dev = dev_id;
495 u32 stat;
496 int count = 0;
497 u16 w;
498
499 while ((stat = davinci_i2c_read_reg(dev, DAVINCI_I2C_IVR_REG))) {
500 dev_dbg(dev->dev, "%s: stat=0x%x\n", __func__, stat);
501 if (count++ == 100) {
502 dev_warn(dev->dev, "Too much work in one IRQ\n");
503 break;
504 }
505
506 switch (stat) {
507 case DAVINCI_I2C_IVR_AL:
508 /* Arbitration lost, must retry */
509 dev->cmd_err |= DAVINCI_I2C_STR_AL;
510 dev->buf_len = 0;
511 complete(&dev->cmd_complete);
512 break;
513
514 case DAVINCI_I2C_IVR_NACK:
515 dev->cmd_err |= DAVINCI_I2C_STR_NACK;
516 dev->buf_len = 0;
517 complete(&dev->cmd_complete);
518 break;
519
520 case DAVINCI_I2C_IVR_ARDY:
521 davinci_i2c_write_reg(dev,
522 DAVINCI_I2C_STR_REG, DAVINCI_I2C_STR_ARDY);
523 if (((dev->buf_len == 0) && (dev->stop != 0)) ||
524 (dev->cmd_err & DAVINCI_I2C_STR_NACK)) {
525 w = davinci_i2c_read_reg(dev,
526 DAVINCI_I2C_MDR_REG);
527 w |= DAVINCI_I2C_MDR_STP;
528 davinci_i2c_write_reg(dev,
529 DAVINCI_I2C_MDR_REG, w);
530 }
531 complete(&dev->cmd_complete);
532 break;
533
534 case DAVINCI_I2C_IVR_RDR:
535 if (dev->buf_len) {
536 *dev->buf++ =
537 davinci_i2c_read_reg(dev,
538 DAVINCI_I2C_DRR_REG);
539 dev->buf_len--;
540 if (dev->buf_len)
541 continue;
542
543 davinci_i2c_write_reg(dev,
544 DAVINCI_I2C_STR_REG,
545 DAVINCI_I2C_IMR_RRDY);
546 } else {
547 /* signal can terminate transfer */
548 terminate_read(dev);
549 }
550 break;
551
552 case DAVINCI_I2C_IVR_XRDY:
553 if (dev->buf_len) {
554 davinci_i2c_write_reg(dev, DAVINCI_I2C_DXR_REG,
555 *dev->buf++);
556 dev->buf_len--;
557 if (dev->buf_len)
558 continue;
559
560 w = davinci_i2c_read_reg(dev,
561 DAVINCI_I2C_IMR_REG);
562 w &= ~DAVINCI_I2C_IMR_XRDY;
563 davinci_i2c_write_reg(dev,
564 DAVINCI_I2C_IMR_REG,
565 w);
566 } else {
567 /* signal can terminate transfer */
568 terminate_write(dev);
569 }
570 break;
571
572 case DAVINCI_I2C_IVR_SCD:
573 davinci_i2c_write_reg(dev,
574 DAVINCI_I2C_STR_REG, DAVINCI_I2C_STR_SCD);
575 complete(&dev->cmd_complete);
576 break;
577
578 case DAVINCI_I2C_IVR_AAS:
579 dev_dbg(dev->dev, "Address as slave interrupt\n");
580 break;
581
582 default:
583 dev_warn(dev->dev, "Unrecognized irq stat %d\n", stat);
584 break;
585 }
586 }
587
588 return count ? IRQ_HANDLED : IRQ_NONE;
589 }
590
591 #ifdef CONFIG_CPU_FREQ
592 static int i2c_davinci_cpufreq_transition(struct notifier_block *nb,
593 unsigned long val, void *data)
594 {
595 struct davinci_i2c_dev *dev;
596
597 dev = container_of(nb, struct davinci_i2c_dev, freq_transition);
598 if (val == CPUFREQ_PRECHANGE) {
599 wait_for_completion(&dev->xfr_complete);
600 davinci_i2c_reset_ctrl(dev, 0);
601 } else if (val == CPUFREQ_POSTCHANGE) {
602 i2c_davinci_calc_clk_dividers(dev);
603 davinci_i2c_reset_ctrl(dev, 1);
604 }
605
606 return 0;
607 }
608
609 static inline int i2c_davinci_cpufreq_register(struct davinci_i2c_dev *dev)
610 {
611 dev->freq_transition.notifier_call = i2c_davinci_cpufreq_transition;
612
613 return cpufreq_register_notifier(&dev->freq_transition,
614 CPUFREQ_TRANSITION_NOTIFIER);
615 }
616
617 static inline void i2c_davinci_cpufreq_deregister(struct davinci_i2c_dev *dev)
618 {
619 cpufreq_unregister_notifier(&dev->freq_transition,
620 CPUFREQ_TRANSITION_NOTIFIER);
621 }
622 #else
623 static inline int i2c_davinci_cpufreq_register(struct davinci_i2c_dev *dev)
624 {
625 return 0;
626 }
627
628 static inline void i2c_davinci_cpufreq_deregister(struct davinci_i2c_dev *dev)
629 {
630 }
631 #endif
632
633 static struct i2c_algorithm i2c_davinci_algo = {
634 .master_xfer = i2c_davinci_xfer,
635 .functionality = i2c_davinci_func,
636 };
637
638 static int davinci_i2c_probe(struct platform_device *pdev)
639 {
640 struct davinci_i2c_dev *dev;
641 struct i2c_adapter *adap;
642 struct resource *mem, *irq, *ioarea;
643 int r;
644
645 /* NOTE: driver uses the static register mapping */
646 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
647 if (!mem) {
648 dev_err(&pdev->dev, "no mem resource?\n");
649 return -ENODEV;
650 }
651
652 irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
653 if (!irq) {
654 dev_err(&pdev->dev, "no irq resource?\n");
655 return -ENODEV;
656 }
657
658 ioarea = request_mem_region(mem->start, resource_size(mem),
659 pdev->name);
660 if (!ioarea) {
661 dev_err(&pdev->dev, "I2C region already claimed\n");
662 return -EBUSY;
663 }
664
665 dev = kzalloc(sizeof(struct davinci_i2c_dev), GFP_KERNEL);
666 if (!dev) {
667 r = -ENOMEM;
668 goto err_release_region;
669 }
670
671 init_completion(&dev->cmd_complete);
672 #ifdef CONFIG_CPU_FREQ
673 init_completion(&dev->xfr_complete);
674 #endif
675 dev->dev = get_device(&pdev->dev);
676 dev->irq = irq->start;
677 platform_set_drvdata(pdev, dev);
678
679 dev->clk = clk_get(&pdev->dev, NULL);
680 if (IS_ERR(dev->clk)) {
681 r = -ENODEV;
682 goto err_free_mem;
683 }
684 clk_enable(dev->clk);
685
686 dev->base = ioremap(mem->start, resource_size(mem));
687 if (!dev->base) {
688 r = -EBUSY;
689 goto err_mem_ioremap;
690 }
691
692 i2c_davinci_init(dev);
693
694 r = request_irq(dev->irq, i2c_davinci_isr, 0, pdev->name, dev);
695 if (r) {
696 dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq);
697 goto err_unuse_clocks;
698 }
699
700 r = i2c_davinci_cpufreq_register(dev);
701 if (r) {
702 dev_err(&pdev->dev, "failed to register cpufreq\n");
703 goto err_free_irq;
704 }
705
706 adap = &dev->adapter;
707 i2c_set_adapdata(adap, dev);
708 adap->owner = THIS_MODULE;
709 adap->class = I2C_CLASS_HWMON;
710 strlcpy(adap->name, "DaVinci I2C adapter", sizeof(adap->name));
711 adap->algo = &i2c_davinci_algo;
712 adap->dev.parent = &pdev->dev;
713 adap->timeout = DAVINCI_I2C_TIMEOUT;
714
715 adap->nr = pdev->id;
716 r = i2c_add_numbered_adapter(adap);
717 if (r) {
718 dev_err(&pdev->dev, "failure adding adapter\n");
719 goto err_free_irq;
720 }
721
722 return 0;
723
724 err_free_irq:
725 free_irq(dev->irq, dev);
726 err_unuse_clocks:
727 iounmap(dev->base);
728 err_mem_ioremap:
729 clk_disable(dev->clk);
730 clk_put(dev->clk);
731 dev->clk = NULL;
732 err_free_mem:
733 platform_set_drvdata(pdev, NULL);
734 put_device(&pdev->dev);
735 kfree(dev);
736 err_release_region:
737 release_mem_region(mem->start, resource_size(mem));
738
739 return r;
740 }
741
742 static int davinci_i2c_remove(struct platform_device *pdev)
743 {
744 struct davinci_i2c_dev *dev = platform_get_drvdata(pdev);
745 struct resource *mem;
746
747 i2c_davinci_cpufreq_deregister(dev);
748
749 platform_set_drvdata(pdev, NULL);
750 i2c_del_adapter(&dev->adapter);
751 put_device(&pdev->dev);
752
753 clk_disable(dev->clk);
754 clk_put(dev->clk);
755 dev->clk = NULL;
756
757 davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, 0);
758 free_irq(IRQ_I2C, dev);
759 iounmap(dev->base);
760 kfree(dev);
761
762 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
763 release_mem_region(mem->start, resource_size(mem));
764 return 0;
765 }
766
767 #ifdef CONFIG_PM
768 static int davinci_i2c_suspend(struct device *dev)
769 {
770 struct platform_device *pdev = to_platform_device(dev);
771 struct davinci_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
772
773 /* put I2C into reset */
774 davinci_i2c_reset_ctrl(i2c_dev, 0);
775 clk_disable(i2c_dev->clk);
776
777 return 0;
778 }
779
780 static int davinci_i2c_resume(struct device *dev)
781 {
782 struct platform_device *pdev = to_platform_device(dev);
783 struct davinci_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
784
785 clk_enable(i2c_dev->clk);
786 /* take I2C out of reset */
787 davinci_i2c_reset_ctrl(i2c_dev, 1);
788
789 return 0;
790 }
791
792 static const struct dev_pm_ops davinci_i2c_pm = {
793 .suspend = davinci_i2c_suspend,
794 .resume = davinci_i2c_resume,
795 };
796
797 #define davinci_i2c_pm_ops (&davinci_i2c_pm)
798 #else
799 #define davinci_i2c_pm_ops NULL
800 #endif
801
802 /* work with hotplug and coldplug */
803 MODULE_ALIAS("platform:i2c_davinci");
804
805 static struct platform_driver davinci_i2c_driver = {
806 .probe = davinci_i2c_probe,
807 .remove = davinci_i2c_remove,
808 .driver = {
809 .name = "i2c_davinci",
810 .owner = THIS_MODULE,
811 .pm = davinci_i2c_pm_ops,
812 },
813 };
814
815 /* I2C may be needed to bring up other drivers */
816 static int __init davinci_i2c_init_driver(void)
817 {
818 return platform_driver_register(&davinci_i2c_driver);
819 }
820 subsys_initcall(davinci_i2c_init_driver);
821
822 static void __exit davinci_i2c_exit_driver(void)
823 {
824 platform_driver_unregister(&davinci_i2c_driver);
825 }
826 module_exit(davinci_i2c_exit_driver);
827
828 MODULE_AUTHOR("Texas Instruments India");
829 MODULE_DESCRIPTION("TI DaVinci I2C bus adapter");
830 MODULE_LICENSE("GPL");
linux-next