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i2c: davinci: use ICPFUNC to toggle I2C as gpio for bus recovery
[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 *
22 */
23 #include <linux/kernel.h>
24 #include <linux/module.h>
25 #include <linux/delay.h>
26 #include <linux/i2c.h>
27 #include <linux/clk.h>
28 #include <linux/errno.h>
29 #include <linux/sched.h>
30 #include <linux/err.h>
31 #include <linux/interrupt.h>
32 #include <linux/platform_device.h>
33 #include <linux/io.h>
34 #include <linux/slab.h>
35 #include <linux/cpufreq.h>
36 #include <linux/gpio.h>
37 #include <linux/of_device.h>
38 #include <linux/platform_data/i2c-davinci.h>
39
40 /* ----- global defines ----------------------------------------------- */
41
42 #define DAVINCI_I2C_TIMEOUT (1*HZ)
43 #define DAVINCI_I2C_MAX_TRIES 2
44 #define I2C_DAVINCI_INTR_ALL (DAVINCI_I2C_IMR_AAS | \
45 DAVINCI_I2C_IMR_SCD | \
46 DAVINCI_I2C_IMR_ARDY | \
47 DAVINCI_I2C_IMR_NACK | \
48 DAVINCI_I2C_IMR_AL)
49
50 #define DAVINCI_I2C_OAR_REG 0x00
51 #define DAVINCI_I2C_IMR_REG 0x04
52 #define DAVINCI_I2C_STR_REG 0x08
53 #define DAVINCI_I2C_CLKL_REG 0x0c
54 #define DAVINCI_I2C_CLKH_REG 0x10
55 #define DAVINCI_I2C_CNT_REG 0x14
56 #define DAVINCI_I2C_DRR_REG 0x18
57 #define DAVINCI_I2C_SAR_REG 0x1c
58 #define DAVINCI_I2C_DXR_REG 0x20
59 #define DAVINCI_I2C_MDR_REG 0x24
60 #define DAVINCI_I2C_IVR_REG 0x28
61 #define DAVINCI_I2C_EMDR_REG 0x2c
62 #define DAVINCI_I2C_PSC_REG 0x30
63 #define DAVINCI_I2C_FUNC_REG 0x48
64 #define DAVINCI_I2C_DIR_REG 0x4c
65 #define DAVINCI_I2C_DIN_REG 0x50
66 #define DAVINCI_I2C_DOUT_REG 0x54
67 #define DAVINCI_I2C_DSET_REG 0x58
68 #define DAVINCI_I2C_DCLR_REG 0x5c
69
70 #define DAVINCI_I2C_IVR_AAS 0x07
71 #define DAVINCI_I2C_IVR_SCD 0x06
72 #define DAVINCI_I2C_IVR_XRDY 0x05
73 #define DAVINCI_I2C_IVR_RDR 0x04
74 #define DAVINCI_I2C_IVR_ARDY 0x03
75 #define DAVINCI_I2C_IVR_NACK 0x02
76 #define DAVINCI_I2C_IVR_AL 0x01
77
78 #define DAVINCI_I2C_STR_BB BIT(12)
79 #define DAVINCI_I2C_STR_RSFULL BIT(11)
80 #define DAVINCI_I2C_STR_SCD BIT(5)
81 #define DAVINCI_I2C_STR_ARDY BIT(2)
82 #define DAVINCI_I2C_STR_NACK BIT(1)
83 #define DAVINCI_I2C_STR_AL BIT(0)
84
85 #define DAVINCI_I2C_MDR_NACK BIT(15)
86 #define DAVINCI_I2C_MDR_STT BIT(13)
87 #define DAVINCI_I2C_MDR_STP BIT(11)
88 #define DAVINCI_I2C_MDR_MST BIT(10)
89 #define DAVINCI_I2C_MDR_TRX BIT(9)
90 #define DAVINCI_I2C_MDR_XA BIT(8)
91 #define DAVINCI_I2C_MDR_RM BIT(7)
92 #define DAVINCI_I2C_MDR_IRS BIT(5)
93
94 #define DAVINCI_I2C_IMR_AAS BIT(6)
95 #define DAVINCI_I2C_IMR_SCD BIT(5)
96 #define DAVINCI_I2C_IMR_XRDY BIT(4)
97 #define DAVINCI_I2C_IMR_RRDY BIT(3)
98 #define DAVINCI_I2C_IMR_ARDY BIT(2)
99 #define DAVINCI_I2C_IMR_NACK BIT(1)
100 #define DAVINCI_I2C_IMR_AL BIT(0)
101
102 /* set SDA and SCL as GPIO */
103 #define DAVINCI_I2C_FUNC_PFUNC0 BIT(0)
104
105 /* set SCL as output when used as GPIO*/
106 #define DAVINCI_I2C_DIR_PDIR0 BIT(0)
107 /* set SDA as output when used as GPIO*/
108 #define DAVINCI_I2C_DIR_PDIR1 BIT(1)
109
110 /* read SCL GPIO level */
111 #define DAVINCI_I2C_DIN_PDIN0 BIT(0)
112 /* read SDA GPIO level */
113 #define DAVINCI_I2C_DIN_PDIN1 BIT(1)
114
115 /*set the SCL GPIO high */
116 #define DAVINCI_I2C_DSET_PDSET0 BIT(0)
117 /*set the SDA GPIO high */
118 #define DAVINCI_I2C_DSET_PDSET1 BIT(1)
119
120 /* set the SCL GPIO low */
121 #define DAVINCI_I2C_DCLR_PDCLR0 BIT(0)
122 /* set the SDA GPIO low */
123 #define DAVINCI_I2C_DCLR_PDCLR1 BIT(1)
124
125 struct davinci_i2c_dev {
126 struct device *dev;
127 void __iomem *base;
128 struct completion cmd_complete;
129 struct clk *clk;
130 int cmd_err;
131 u8 *buf;
132 size_t buf_len;
133 int irq;
134 int stop;
135 u8 terminate;
136 struct i2c_adapter adapter;
137 #ifdef CONFIG_CPU_FREQ
138 struct completion xfr_complete;
139 struct notifier_block freq_transition;
140 #endif
141 struct davinci_i2c_platform_data *pdata;
142 };
143
144 /* default platform data to use if not supplied in the platform_device */
145 static struct davinci_i2c_platform_data davinci_i2c_platform_data_default = {
146 .bus_freq = 100,
147 .bus_delay = 0,
148 };
149
150 static inline void davinci_i2c_write_reg(struct davinci_i2c_dev *i2c_dev,
151 int reg, u16 val)
152 {
153 writew_relaxed(val, i2c_dev->base + reg);
154 }
155
156 static inline u16 davinci_i2c_read_reg(struct davinci_i2c_dev *i2c_dev, int reg)
157 {
158 return readw_relaxed(i2c_dev->base + reg);
159 }
160
161 static inline void davinci_i2c_reset_ctrl(struct davinci_i2c_dev *i2c_dev,
162 int val)
163 {
164 u16 w;
165
166 w = davinci_i2c_read_reg(i2c_dev, DAVINCI_I2C_MDR_REG);
167 if (!val) /* put I2C into reset */
168 w &= ~DAVINCI_I2C_MDR_IRS;
169 else /* take I2C out of reset */
170 w |= DAVINCI_I2C_MDR_IRS;
171
172 davinci_i2c_write_reg(i2c_dev, DAVINCI_I2C_MDR_REG, w);
173 }
174
175 static void i2c_davinci_calc_clk_dividers(struct davinci_i2c_dev *dev)
176 {
177 struct davinci_i2c_platform_data *pdata = dev->pdata;
178 u16 psc;
179 u32 clk;
180 u32 d;
181 u32 clkh;
182 u32 clkl;
183 u32 input_clock = clk_get_rate(dev->clk);
184
185 /* NOTE: I2C Clock divider programming info
186 * As per I2C specs the following formulas provide prescaler
187 * and low/high divider values
188 * input clk --> PSC Div -----------> ICCL/H Div --> output clock
189 * module clk
190 *
191 * output clk = module clk / (PSC + 1) [ (ICCL + d) + (ICCH + d) ]
192 *
193 * Thus,
194 * (ICCL + ICCH) = clk = (input clk / ((psc +1) * output clk)) - 2d;
195 *
196 * where if PSC == 0, d = 7,
197 * if PSC == 1, d = 6
198 * if PSC > 1 , d = 5
199 */
200
201 /* get minimum of 7 MHz clock, but max of 12 MHz */
202 psc = (input_clock / 7000000) - 1;
203 if ((input_clock / (psc + 1)) > 12000000)
204 psc++; /* better to run under spec than over */
205 d = (psc >= 2) ? 5 : 7 - psc;
206
207 clk = ((input_clock / (psc + 1)) / (pdata->bus_freq * 1000)) - (d << 1);
208 clkh = clk >> 1;
209 clkl = clk - clkh;
210
211 davinci_i2c_write_reg(dev, DAVINCI_I2C_PSC_REG, psc);
212 davinci_i2c_write_reg(dev, DAVINCI_I2C_CLKH_REG, clkh);
213 davinci_i2c_write_reg(dev, DAVINCI_I2C_CLKL_REG, clkl);
214
215 dev_dbg(dev->dev, "input_clock = %d, CLK = %d\n", input_clock, clk);
216 }
217
218 /*
219 * This function configures I2C and brings I2C out of reset.
220 * This function is called during I2C init function. This function
221 * also gets called if I2C encounters any errors.
222 */
223 static int i2c_davinci_init(struct davinci_i2c_dev *dev)
224 {
225 struct davinci_i2c_platform_data *pdata = dev->pdata;
226
227 /* put I2C into reset */
228 davinci_i2c_reset_ctrl(dev, 0);
229
230 /* compute clock dividers */
231 i2c_davinci_calc_clk_dividers(dev);
232
233 /* Respond at reserved "SMBus Host" slave address" (and zero);
234 * we seem to have no option to not respond...
235 */
236 davinci_i2c_write_reg(dev, DAVINCI_I2C_OAR_REG, 0x08);
237
238 dev_dbg(dev->dev, "PSC = %d\n",
239 davinci_i2c_read_reg(dev, DAVINCI_I2C_PSC_REG));
240 dev_dbg(dev->dev, "CLKL = %d\n",
241 davinci_i2c_read_reg(dev, DAVINCI_I2C_CLKL_REG));
242 dev_dbg(dev->dev, "CLKH = %d\n",
243 davinci_i2c_read_reg(dev, DAVINCI_I2C_CLKH_REG));
244 dev_dbg(dev->dev, "bus_freq = %dkHz, bus_delay = %d\n",
245 pdata->bus_freq, pdata->bus_delay);
246
247
248 /* Take the I2C module out of reset: */
249 davinci_i2c_reset_ctrl(dev, 1);
250
251 /* Enable interrupts */
252 davinci_i2c_write_reg(dev, DAVINCI_I2C_IMR_REG, I2C_DAVINCI_INTR_ALL);
253
254 return 0;
255 }
256
257 /*
258 * This routine does i2c bus recovery by using i2c_generic_gpio_recovery
259 * which is provided by I2C Bus recovery infrastructure.
260 */
261 static void davinci_i2c_prepare_recovery(struct i2c_adapter *adap)
262 {
263 struct davinci_i2c_dev *dev = i2c_get_adapdata(adap);
264
265 /* Disable interrupts */
266 davinci_i2c_write_reg(dev, DAVINCI_I2C_IMR_REG, 0);
267
268 /* put I2C into reset */
269 davinci_i2c_reset_ctrl(dev, 0);
270 }
271
272 static void davinci_i2c_unprepare_recovery(struct i2c_adapter *adap)
273 {
274 struct davinci_i2c_dev *dev = i2c_get_adapdata(adap);
275
276 i2c_davinci_init(dev);
277 }
278
279 static struct i2c_bus_recovery_info davinci_i2c_gpio_recovery_info = {
280 .recover_bus = i2c_generic_gpio_recovery,
281 .prepare_recovery = davinci_i2c_prepare_recovery,
282 .unprepare_recovery = davinci_i2c_unprepare_recovery,
283 };
284
285 static void davinci_i2c_set_scl(struct i2c_adapter *adap, int val)
286 {
287 struct davinci_i2c_dev *dev = i2c_get_adapdata(adap);
288
289 if (val)
290 davinci_i2c_write_reg(dev, DAVINCI_I2C_DSET_REG,
291 DAVINCI_I2C_DSET_PDSET0);
292 else
293 davinci_i2c_write_reg(dev, DAVINCI_I2C_DCLR_REG,
294 DAVINCI_I2C_DCLR_PDCLR0);
295 }
296
297 static int davinci_i2c_get_scl(struct i2c_adapter *adap)
298 {
299 struct davinci_i2c_dev *dev = i2c_get_adapdata(adap);
300 int val;
301
302 /* read the state of SCL */
303 val = davinci_i2c_read_reg(dev, DAVINCI_I2C_DIN_REG);
304 return val & DAVINCI_I2C_DIN_PDIN0;
305 }
306
307 static int davinci_i2c_get_sda(struct i2c_adapter *adap)
308 {
309 struct davinci_i2c_dev *dev = i2c_get_adapdata(adap);
310 int val;
311
312 /* read the state of SDA */
313 val = davinci_i2c_read_reg(dev, DAVINCI_I2C_DIN_REG);
314 return val & DAVINCI_I2C_DIN_PDIN1;
315 }
316
317 static void davinci_i2c_scl_prepare_recovery(struct i2c_adapter *adap)
318 {
319 struct davinci_i2c_dev *dev = i2c_get_adapdata(adap);
320
321 davinci_i2c_prepare_recovery(adap);
322
323 /* SCL output, SDA input */
324 davinci_i2c_write_reg(dev, DAVINCI_I2C_DIR_REG, DAVINCI_I2C_DIR_PDIR0);
325
326 /* change to GPIO mode */
327 davinci_i2c_write_reg(dev, DAVINCI_I2C_FUNC_REG,
328 DAVINCI_I2C_FUNC_PFUNC0);
329 }
330
331 static void davinci_i2c_scl_unprepare_recovery(struct i2c_adapter *adap)
332 {
333 struct davinci_i2c_dev *dev = i2c_get_adapdata(adap);
334
335 /* change back to I2C mode */
336 davinci_i2c_write_reg(dev, DAVINCI_I2C_FUNC_REG, 0);
337
338 davinci_i2c_unprepare_recovery(adap);
339 }
340
341 static struct i2c_bus_recovery_info davinci_i2c_scl_recovery_info = {
342 .recover_bus = i2c_generic_scl_recovery,
343 .set_scl = davinci_i2c_set_scl,
344 .get_scl = davinci_i2c_get_scl,
345 .get_sda = davinci_i2c_get_sda,
346 .prepare_recovery = davinci_i2c_scl_prepare_recovery,
347 .unprepare_recovery = davinci_i2c_scl_unprepare_recovery,
348 };
349
350 /*
351 * Waiting for bus not busy
352 */
353 static int i2c_davinci_wait_bus_not_busy(struct davinci_i2c_dev *dev,
354 char allow_sleep)
355 {
356 unsigned long timeout;
357 static u16 to_cnt;
358
359 timeout = jiffies + dev->adapter.timeout;
360 while (davinci_i2c_read_reg(dev, DAVINCI_I2C_STR_REG)
361 & DAVINCI_I2C_STR_BB) {
362 if (to_cnt <= DAVINCI_I2C_MAX_TRIES) {
363 if (time_after(jiffies, timeout)) {
364 dev_warn(dev->dev,
365 "timeout waiting for bus ready\n");
366 to_cnt++;
367 return -ETIMEDOUT;
368 } else {
369 to_cnt = 0;
370 i2c_recover_bus(&dev->adapter);
371 }
372 }
373 if (allow_sleep)
374 schedule_timeout(1);
375 }
376
377 return 0;
378 }
379
380 /*
381 * Low level master read/write transaction. This function is called
382 * from i2c_davinci_xfer.
383 */
384 static int
385 i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop)
386 {
387 struct davinci_i2c_dev *dev = i2c_get_adapdata(adap);
388 struct davinci_i2c_platform_data *pdata = dev->pdata;
389 u32 flag;
390 u16 w;
391 unsigned long time_left;
392
393 /* Introduce a delay, required for some boards (e.g Davinci EVM) */
394 if (pdata->bus_delay)
395 udelay(pdata->bus_delay);
396
397 /* set the slave address */
398 davinci_i2c_write_reg(dev, DAVINCI_I2C_SAR_REG, msg->addr);
399
400 dev->buf = msg->buf;
401 dev->buf_len = msg->len;
402 dev->stop = stop;
403
404 davinci_i2c_write_reg(dev, DAVINCI_I2C_CNT_REG, dev->buf_len);
405
406 reinit_completion(&dev->cmd_complete);
407 dev->cmd_err = 0;
408
409 /* Take I2C out of reset and configure it as master */
410 flag = DAVINCI_I2C_MDR_IRS | DAVINCI_I2C_MDR_MST;
411
412 /* if the slave address is ten bit address, enable XA bit */
413 if (msg->flags & I2C_M_TEN)
414 flag |= DAVINCI_I2C_MDR_XA;
415 if (!(msg->flags & I2C_M_RD))
416 flag |= DAVINCI_I2C_MDR_TRX;
417 if (msg->len == 0)
418 flag |= DAVINCI_I2C_MDR_RM;
419
420 /* Enable receive or transmit interrupts */
421 w = davinci_i2c_read_reg(dev, DAVINCI_I2C_IMR_REG);
422 if (msg->flags & I2C_M_RD)
423 w |= DAVINCI_I2C_IMR_RRDY;
424 else
425 w |= DAVINCI_I2C_IMR_XRDY;
426 davinci_i2c_write_reg(dev, DAVINCI_I2C_IMR_REG, w);
427
428 dev->terminate = 0;
429
430 /*
431 * Write mode register first as needed for correct behaviour
432 * on OMAP-L138, but don't set STT yet to avoid a race with XRDY
433 * occurring before we have loaded DXR
434 */
435 davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, flag);
436
437 /*
438 * First byte should be set here, not after interrupt,
439 * because transmit-data-ready interrupt can come before
440 * NACK-interrupt during sending of previous message and
441 * ICDXR may have wrong data
442 * It also saves us one interrupt, slightly faster
443 */
444 if ((!(msg->flags & I2C_M_RD)) && dev->buf_len) {
445 davinci_i2c_write_reg(dev, DAVINCI_I2C_DXR_REG, *dev->buf++);
446 dev->buf_len--;
447 }
448
449 /* Set STT to begin transmit now DXR is loaded */
450 flag |= DAVINCI_I2C_MDR_STT;
451 if (stop && msg->len != 0)
452 flag |= DAVINCI_I2C_MDR_STP;
453 davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, flag);
454
455 time_left = wait_for_completion_timeout(&dev->cmd_complete,
456 dev->adapter.timeout);
457 if (!time_left) {
458 dev_err(dev->dev, "controller timed out\n");
459 i2c_recover_bus(adap);
460 dev->buf_len = 0;
461 return -ETIMEDOUT;
462 }
463 if (dev->buf_len) {
464 /* This should be 0 if all bytes were transferred
465 * or dev->cmd_err denotes an error.
466 */
467 dev_err(dev->dev, "abnormal termination buf_len=%i\n",
468 dev->buf_len);
469 dev->terminate = 1;
470 wmb();
471 dev->buf_len = 0;
472 return -EREMOTEIO;
473 }
474
475 /* no error */
476 if (likely(!dev->cmd_err))
477 return msg->len;
478
479 /* We have an error */
480 if (dev->cmd_err & DAVINCI_I2C_STR_AL) {
481 i2c_davinci_init(dev);
482 return -EIO;
483 }
484
485 if (dev->cmd_err & DAVINCI_I2C_STR_NACK) {
486 if (msg->flags & I2C_M_IGNORE_NAK)
487 return msg->len;
488 w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG);
489 w |= DAVINCI_I2C_MDR_STP;
490 davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w);
491 return -EREMOTEIO;
492 }
493 return -EIO;
494 }
495
496 /*
497 * Prepare controller for a transaction and call i2c_davinci_xfer_msg
498 */
499 static int
500 i2c_davinci_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
501 {
502 struct davinci_i2c_dev *dev = i2c_get_adapdata(adap);
503 int i;
504 int ret;
505
506 dev_dbg(dev->dev, "%s: msgs: %d\n", __func__, num);
507
508 ret = i2c_davinci_wait_bus_not_busy(dev, 1);
509 if (ret < 0) {
510 dev_warn(dev->dev, "timeout waiting for bus ready\n");
511 return ret;
512 }
513
514 for (i = 0; i < num; i++) {
515 ret = i2c_davinci_xfer_msg(adap, &msgs[i], (i == (num - 1)));
516 dev_dbg(dev->dev, "%s [%d/%d] ret: %d\n", __func__, i + 1, num,
517 ret);
518 if (ret < 0)
519 return ret;
520 }
521
522 #ifdef CONFIG_CPU_FREQ
523 complete(&dev->xfr_complete);
524 #endif
525
526 return num;
527 }
528
529 static u32 i2c_davinci_func(struct i2c_adapter *adap)
530 {
531 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
532 }
533
534 static void terminate_read(struct davinci_i2c_dev *dev)
535 {
536 u16 w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG);
537 w |= DAVINCI_I2C_MDR_NACK;
538 davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w);
539
540 /* Throw away data */
541 davinci_i2c_read_reg(dev, DAVINCI_I2C_DRR_REG);
542 if (!dev->terminate)
543 dev_err(dev->dev, "RDR IRQ while no data requested\n");
544 }
545 static void terminate_write(struct davinci_i2c_dev *dev)
546 {
547 u16 w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG);
548 w |= DAVINCI_I2C_MDR_RM | DAVINCI_I2C_MDR_STP;
549 davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w);
550
551 if (!dev->terminate)
552 dev_dbg(dev->dev, "TDR IRQ while no data to send\n");
553 }
554
555 /*
556 * Interrupt service routine. This gets called whenever an I2C interrupt
557 * occurs.
558 */
559 static irqreturn_t i2c_davinci_isr(int this_irq, void *dev_id)
560 {
561 struct davinci_i2c_dev *dev = dev_id;
562 u32 stat;
563 int count = 0;
564 u16 w;
565
566 while ((stat = davinci_i2c_read_reg(dev, DAVINCI_I2C_IVR_REG))) {
567 dev_dbg(dev->dev, "%s: stat=0x%x\n", __func__, stat);
568 if (count++ == 100) {
569 dev_warn(dev->dev, "Too much work in one IRQ\n");
570 break;
571 }
572
573 switch (stat) {
574 case DAVINCI_I2C_IVR_AL:
575 /* Arbitration lost, must retry */
576 dev->cmd_err |= DAVINCI_I2C_STR_AL;
577 dev->buf_len = 0;
578 complete(&dev->cmd_complete);
579 break;
580
581 case DAVINCI_I2C_IVR_NACK:
582 dev->cmd_err |= DAVINCI_I2C_STR_NACK;
583 dev->buf_len = 0;
584 complete(&dev->cmd_complete);
585 break;
586
587 case DAVINCI_I2C_IVR_ARDY:
588 davinci_i2c_write_reg(dev,
589 DAVINCI_I2C_STR_REG, DAVINCI_I2C_STR_ARDY);
590 if (((dev->buf_len == 0) && (dev->stop != 0)) ||
591 (dev->cmd_err & DAVINCI_I2C_STR_NACK)) {
592 w = davinci_i2c_read_reg(dev,
593 DAVINCI_I2C_MDR_REG);
594 w |= DAVINCI_I2C_MDR_STP;
595 davinci_i2c_write_reg(dev,
596 DAVINCI_I2C_MDR_REG, w);
597 }
598 complete(&dev->cmd_complete);
599 break;
600
601 case DAVINCI_I2C_IVR_RDR:
602 if (dev->buf_len) {
603 *dev->buf++ =
604 davinci_i2c_read_reg(dev,
605 DAVINCI_I2C_DRR_REG);
606 dev->buf_len--;
607 if (dev->buf_len)
608 continue;
609
610 davinci_i2c_write_reg(dev,
611 DAVINCI_I2C_STR_REG,
612 DAVINCI_I2C_IMR_RRDY);
613 } else {
614 /* signal can terminate transfer */
615 terminate_read(dev);
616 }
617 break;
618
619 case DAVINCI_I2C_IVR_XRDY:
620 if (dev->buf_len) {
621 davinci_i2c_write_reg(dev, DAVINCI_I2C_DXR_REG,
622 *dev->buf++);
623 dev->buf_len--;
624 if (dev->buf_len)
625 continue;
626
627 w = davinci_i2c_read_reg(dev,
628 DAVINCI_I2C_IMR_REG);
629 w &= ~DAVINCI_I2C_IMR_XRDY;
630 davinci_i2c_write_reg(dev,
631 DAVINCI_I2C_IMR_REG,
632 w);
633 } else {
634 /* signal can terminate transfer */
635 terminate_write(dev);
636 }
637 break;
638
639 case DAVINCI_I2C_IVR_SCD:
640 davinci_i2c_write_reg(dev,
641 DAVINCI_I2C_STR_REG, DAVINCI_I2C_STR_SCD);
642 complete(&dev->cmd_complete);
643 break;
644
645 case DAVINCI_I2C_IVR_AAS:
646 dev_dbg(dev->dev, "Address as slave interrupt\n");
647 break;
648
649 default:
650 dev_warn(dev->dev, "Unrecognized irq stat %d\n", stat);
651 break;
652 }
653 }
654
655 return count ? IRQ_HANDLED : IRQ_NONE;
656 }
657
658 #ifdef CONFIG_CPU_FREQ
659 static int i2c_davinci_cpufreq_transition(struct notifier_block *nb,
660 unsigned long val, void *data)
661 {
662 struct davinci_i2c_dev *dev;
663
664 dev = container_of(nb, struct davinci_i2c_dev, freq_transition);
665 if (val == CPUFREQ_PRECHANGE) {
666 wait_for_completion(&dev->xfr_complete);
667 davinci_i2c_reset_ctrl(dev, 0);
668 } else if (val == CPUFREQ_POSTCHANGE) {
669 i2c_davinci_calc_clk_dividers(dev);
670 davinci_i2c_reset_ctrl(dev, 1);
671 }
672
673 return 0;
674 }
675
676 static inline int i2c_davinci_cpufreq_register(struct davinci_i2c_dev *dev)
677 {
678 dev->freq_transition.notifier_call = i2c_davinci_cpufreq_transition;
679
680 return cpufreq_register_notifier(&dev->freq_transition,
681 CPUFREQ_TRANSITION_NOTIFIER);
682 }
683
684 static inline void i2c_davinci_cpufreq_deregister(struct davinci_i2c_dev *dev)
685 {
686 cpufreq_unregister_notifier(&dev->freq_transition,
687 CPUFREQ_TRANSITION_NOTIFIER);
688 }
689 #else
690 static inline int i2c_davinci_cpufreq_register(struct davinci_i2c_dev *dev)
691 {
692 return 0;
693 }
694
695 static inline void i2c_davinci_cpufreq_deregister(struct davinci_i2c_dev *dev)
696 {
697 }
698 #endif
699
700 static struct i2c_algorithm i2c_davinci_algo = {
701 .master_xfer = i2c_davinci_xfer,
702 .functionality = i2c_davinci_func,
703 };
704
705 static const struct of_device_id davinci_i2c_of_match[] = {
706 {.compatible = "ti,davinci-i2c", },
707 {},
708 };
709 MODULE_DEVICE_TABLE(of, davinci_i2c_of_match);
710
711 static int davinci_i2c_probe(struct platform_device *pdev)
712 {
713 struct davinci_i2c_dev *dev;
714 struct i2c_adapter *adap;
715 struct resource *mem;
716 int r, irq;
717
718 irq = platform_get_irq(pdev, 0);
719 if (irq <= 0) {
720 if (!irq)
721 irq = -ENXIO;
722 if (irq != -EPROBE_DEFER)
723 dev_err(&pdev->dev,
724 "can't get irq resource ret=%d\n", irq);
725 return irq;
726 }
727
728 dev = devm_kzalloc(&pdev->dev, sizeof(struct davinci_i2c_dev),
729 GFP_KERNEL);
730 if (!dev) {
731 dev_err(&pdev->dev, "Memory allocation failed\n");
732 return -ENOMEM;
733 }
734
735 init_completion(&dev->cmd_complete);
736 #ifdef CONFIG_CPU_FREQ
737 init_completion(&dev->xfr_complete);
738 #endif
739 dev->dev = &pdev->dev;
740 dev->irq = irq;
741 dev->pdata = dev_get_platdata(&pdev->dev);
742 platform_set_drvdata(pdev, dev);
743
744 if (!dev->pdata && pdev->dev.of_node) {
745 u32 prop;
746
747 dev->pdata = devm_kzalloc(&pdev->dev,
748 sizeof(struct davinci_i2c_platform_data), GFP_KERNEL);
749 if (!dev->pdata)
750 return -ENOMEM;
751
752 memcpy(dev->pdata, &davinci_i2c_platform_data_default,
753 sizeof(struct davinci_i2c_platform_data));
754 if (!of_property_read_u32(pdev->dev.of_node, "clock-frequency",
755 &prop))
756 dev->pdata->bus_freq = prop / 1000;
757
758 dev->pdata->has_pfunc =
759 of_property_read_bool(pdev->dev.of_node,
760 "ti,has-pfunc");
761 } else if (!dev->pdata) {
762 dev->pdata = &davinci_i2c_platform_data_default;
763 }
764
765 dev->clk = devm_clk_get(&pdev->dev, NULL);
766 if (IS_ERR(dev->clk))
767 return -ENODEV;
768 clk_prepare_enable(dev->clk);
769
770 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
771 dev->base = devm_ioremap_resource(&pdev->dev, mem);
772 if (IS_ERR(dev->base)) {
773 r = PTR_ERR(dev->base);
774 goto err_unuse_clocks;
775 }
776
777 i2c_davinci_init(dev);
778
779 r = devm_request_irq(&pdev->dev, dev->irq, i2c_davinci_isr, 0,
780 pdev->name, dev);
781 if (r) {
782 dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq);
783 goto err_unuse_clocks;
784 }
785
786 r = i2c_davinci_cpufreq_register(dev);
787 if (r) {
788 dev_err(&pdev->dev, "failed to register cpufreq\n");
789 goto err_unuse_clocks;
790 }
791
792 adap = &dev->adapter;
793 i2c_set_adapdata(adap, dev);
794 adap->owner = THIS_MODULE;
795 adap->class = I2C_CLASS_DEPRECATED;
796 strlcpy(adap->name, "DaVinci I2C adapter", sizeof(adap->name));
797 adap->algo = &i2c_davinci_algo;
798 adap->dev.parent = &pdev->dev;
799 adap->timeout = DAVINCI_I2C_TIMEOUT;
800 adap->dev.of_node = pdev->dev.of_node;
801
802 if (dev->pdata->has_pfunc)
803 adap->bus_recovery_info = &davinci_i2c_scl_recovery_info;
804 else if (dev->pdata->scl_pin) {
805 adap->bus_recovery_info = &davinci_i2c_gpio_recovery_info;
806 adap->bus_recovery_info->scl_gpio = dev->pdata->scl_pin;
807 adap->bus_recovery_info->sda_gpio = dev->pdata->sda_pin;
808 }
809
810 adap->nr = pdev->id;
811 r = i2c_add_numbered_adapter(adap);
812 if (r) {
813 dev_err(&pdev->dev, "failure adding adapter\n");
814 goto err_unuse_clocks;
815 }
816
817 return 0;
818
819 err_unuse_clocks:
820 clk_disable_unprepare(dev->clk);
821 dev->clk = NULL;
822 return r;
823 }
824
825 static int davinci_i2c_remove(struct platform_device *pdev)
826 {
827 struct davinci_i2c_dev *dev = platform_get_drvdata(pdev);
828
829 i2c_davinci_cpufreq_deregister(dev);
830
831 i2c_del_adapter(&dev->adapter);
832
833 clk_disable_unprepare(dev->clk);
834 dev->clk = NULL;
835
836 davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, 0);
837
838 return 0;
839 }
840
841 #ifdef CONFIG_PM
842 static int davinci_i2c_suspend(struct device *dev)
843 {
844 struct platform_device *pdev = to_platform_device(dev);
845 struct davinci_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
846
847 /* put I2C into reset */
848 davinci_i2c_reset_ctrl(i2c_dev, 0);
849 clk_disable_unprepare(i2c_dev->clk);
850
851 return 0;
852 }
853
854 static int davinci_i2c_resume(struct device *dev)
855 {
856 struct platform_device *pdev = to_platform_device(dev);
857 struct davinci_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
858
859 clk_prepare_enable(i2c_dev->clk);
860 /* take I2C out of reset */
861 davinci_i2c_reset_ctrl(i2c_dev, 1);
862
863 return 0;
864 }
865
866 static const struct dev_pm_ops davinci_i2c_pm = {
867 .suspend = davinci_i2c_suspend,
868 .resume = davinci_i2c_resume,
869 };
870
871 #define davinci_i2c_pm_ops (&davinci_i2c_pm)
872 #else
873 #define davinci_i2c_pm_ops NULL
874 #endif
875
876 /* work with hotplug and coldplug */
877 MODULE_ALIAS("platform:i2c_davinci");
878
879 static struct platform_driver davinci_i2c_driver = {
880 .probe = davinci_i2c_probe,
881 .remove = davinci_i2c_remove,
882 .driver = {
883 .name = "i2c_davinci",
884 .pm = davinci_i2c_pm_ops,
885 .of_match_table = davinci_i2c_of_match,
886 },
887 };
888
889 /* I2C may be needed to bring up other drivers */
890 static int __init davinci_i2c_init_driver(void)
891 {
892 return platform_driver_register(&davinci_i2c_driver);
893 }
894 subsys_initcall(davinci_i2c_init_driver);
895
896 static void __exit davinci_i2c_exit_driver(void)
897 {
898 platform_driver_unregister(&davinci_i2c_driver);
899 }
900 module_exit(davinci_i2c_exit_driver);
901
902 MODULE_AUTHOR("Texas Instruments India");
903 MODULE_DESCRIPTION("TI DaVinci I2C bus adapter");
904 MODULE_LICENSE("GPL");
Linux kernel - Deliverables
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