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fs: use kmem_cache_zalloc instead
[pv_ops_mirror.git] / drivers / i2c / busses / i2c-bfin-twi.c
blob67224a424aba4cbf659cb969b57d9fb24c1e1d81
1 /*
2 * drivers/i2c/busses/i2c-bfin-twi.c
3 *
4 * Description: Driver for Blackfin Two Wire Interface
5 *
6 * Author: sonicz <sonic.zhang@analog.com>
7 *
8 * Copyright (c) 2005-2007 Analog Devices, Inc.
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 */
24
25 #include <linux/module.h>
26 #include <linux/kernel.h>
27 #include <linux/init.h>
28 #include <linux/i2c.h>
29 #include <linux/mm.h>
30 #include <linux/timer.h>
31 #include <linux/spinlock.h>
32 #include <linux/completion.h>
33 #include <linux/interrupt.h>
34 #include <linux/platform_device.h>
35
36 #include <asm/blackfin.h>
37 #include <asm/irq.h>
38
39 #define POLL_TIMEOUT (2 * HZ)
40
41 /* SMBus mode*/
42 #define TWI_I2C_MODE_STANDARD 0x01
43 #define TWI_I2C_MODE_STANDARDSUB 0x02
44 #define TWI_I2C_MODE_COMBINED 0x04
45
46 struct bfin_twi_iface {
47 int irq;
48 spinlock_t lock;
49 char read_write;
50 u8 command;
51 u8 *transPtr;
52 int readNum;
53 int writeNum;
54 int cur_mode;
55 int manual_stop;
56 int result;
57 int timeout_count;
58 struct timer_list timeout_timer;
59 struct i2c_adapter adap;
60 struct completion complete;
61 };
62
63 static struct bfin_twi_iface twi_iface;
64
65 static void bfin_twi_handle_interrupt(struct bfin_twi_iface *iface)
66 {
67 unsigned short twi_int_status = bfin_read_TWI_INT_STAT();
68 unsigned short mast_stat = bfin_read_TWI_MASTER_STAT();
69
70 if (twi_int_status & XMTSERV) {
71 /* Transmit next data */
72 if (iface->writeNum > 0) {
73 bfin_write_TWI_XMT_DATA8(*(iface->transPtr++));
74 iface->writeNum--;
75 }
76 /* start receive immediately after complete sending in
77 * combine mode.
78 */
79 else if (iface->cur_mode == TWI_I2C_MODE_COMBINED) {
80 bfin_write_TWI_MASTER_CTL(bfin_read_TWI_MASTER_CTL()
81 | MDIR | RSTART);
82 } else if (iface->manual_stop)
83 bfin_write_TWI_MASTER_CTL(bfin_read_TWI_MASTER_CTL()
84 | STOP);
85 SSYNC();
86 /* Clear status */
87 bfin_write_TWI_INT_STAT(XMTSERV);
88 SSYNC();
89 }
90 if (twi_int_status & RCVSERV) {
91 if (iface->readNum > 0) {
92 /* Receive next data */
93 *(iface->transPtr) = bfin_read_TWI_RCV_DATA8();
94 if (iface->cur_mode == TWI_I2C_MODE_COMBINED) {
95 /* Change combine mode into sub mode after
96 * read first data.
97 */
98 iface->cur_mode = TWI_I2C_MODE_STANDARDSUB;
99 /* Get read number from first byte in block
100 * combine mode.
101 */
102 if (iface->readNum == 1 && iface->manual_stop)
103 iface->readNum = *iface->transPtr + 1;
104 }
105 iface->transPtr++;
106 iface->readNum--;
107 } else if (iface->manual_stop) {
108 bfin_write_TWI_MASTER_CTL(bfin_read_TWI_MASTER_CTL()
109 | STOP);
110 SSYNC();
111 }
112 /* Clear interrupt source */
113 bfin_write_TWI_INT_STAT(RCVSERV);
114 SSYNC();
115 }
116 if (twi_int_status & MERR) {
117 bfin_write_TWI_INT_STAT(MERR);
118 bfin_write_TWI_INT_MASK(0);
119 bfin_write_TWI_MASTER_STAT(0x3e);
120 bfin_write_TWI_MASTER_CTL(0);
121 SSYNC();
122 iface->result = -1;
123 /* if both err and complete int stats are set, return proper
124 * results.
125 */
126 if (twi_int_status & MCOMP) {
127 bfin_write_TWI_INT_STAT(MCOMP);
128 bfin_write_TWI_INT_MASK(0);
129 bfin_write_TWI_MASTER_CTL(0);
130 SSYNC();
131 /* If it is a quick transfer, only address bug no data,
132 * not an err, return 1.
133 */
134 if (iface->writeNum == 0 && (mast_stat & BUFRDERR))
135 iface->result = 1;
136 /* If address not acknowledged return -1,
137 * else return 0.
138 */
139 else if (!(mast_stat & ANAK))
140 iface->result = 0;
141 }
142 complete(&iface->complete);
143 return;
144 }
145 if (twi_int_status & MCOMP) {
146 bfin_write_TWI_INT_STAT(MCOMP);
147 SSYNC();
148 if (iface->cur_mode == TWI_I2C_MODE_COMBINED) {
149 if (iface->readNum == 0) {
150 /* set the read number to 1 and ask for manual
151 * stop in block combine mode
152 */
153 iface->readNum = 1;
154 iface->manual_stop = 1;
155 bfin_write_TWI_MASTER_CTL(
156 bfin_read_TWI_MASTER_CTL()
157 | (0xff << 6));
158 } else {
159 /* set the readd number in other
160 * combine mode.
161 */
162 bfin_write_TWI_MASTER_CTL(
163 (bfin_read_TWI_MASTER_CTL() &
164 (~(0xff << 6))) |
165 ( iface->readNum << 6));
166 }
167 /* remove restart bit and enable master receive */
168 bfin_write_TWI_MASTER_CTL(bfin_read_TWI_MASTER_CTL() &
169 ~RSTART);
170 bfin_write_TWI_MASTER_CTL(bfin_read_TWI_MASTER_CTL() |
171 MEN | MDIR);
172 SSYNC();
173 } else {
174 iface->result = 1;
175 bfin_write_TWI_INT_MASK(0);
176 bfin_write_TWI_MASTER_CTL(0);
177 SSYNC();
178 complete(&iface->complete);
179 }
180 }
181 }
182
183 /* Interrupt handler */
184 static irqreturn_t bfin_twi_interrupt_entry(int irq, void *dev_id)
185 {
186 struct bfin_twi_iface *iface = dev_id;
187 unsigned long flags;
188
189 spin_lock_irqsave(&iface->lock, flags);
190 del_timer(&iface->timeout_timer);
191 bfin_twi_handle_interrupt(iface);
192 spin_unlock_irqrestore(&iface->lock, flags);
193 return IRQ_HANDLED;
194 }
195
196 static void bfin_twi_timeout(unsigned long data)
197 {
198 struct bfin_twi_iface *iface = (struct bfin_twi_iface *)data;
199 unsigned long flags;
200
201 spin_lock_irqsave(&iface->lock, flags);
202 bfin_twi_handle_interrupt(iface);
203 if (iface->result == 0) {
204 iface->timeout_count--;
205 if (iface->timeout_count > 0) {
206 iface->timeout_timer.expires = jiffies + POLL_TIMEOUT;
207 add_timer(&iface->timeout_timer);
208 } else {
209 iface->result = -1;
210 complete(&iface->complete);
211 }
212 }
213 spin_unlock_irqrestore(&iface->lock, flags);
214 }
215
216 /*
217 * Generic i2c master transfer entrypoint
218 */
219 static int bfin_twi_master_xfer(struct i2c_adapter *adap,
220 struct i2c_msg *msgs, int num)
221 {
222 struct bfin_twi_iface *iface = adap->algo_data;
223 struct i2c_msg *pmsg;
224 int i, ret;
225 int rc = 0;
226
227 if (!(bfin_read_TWI_CONTROL() & TWI_ENA))
228 return -ENXIO;
229
230 while (bfin_read_TWI_MASTER_STAT() & BUSBUSY) {
231 yield();
232 }
233
234 ret = 0;
235 for (i = 0; rc >= 0 && i < num; i++) {
236 pmsg = &msgs[i];
237 if (pmsg->flags & I2C_M_TEN) {
238 dev_err(&(adap->dev), "i2c-bfin-twi: 10 bits addr "
239 "not supported !\n");
240 rc = -EINVAL;
241 break;
242 }
243
244 iface->cur_mode = TWI_I2C_MODE_STANDARD;
245 iface->manual_stop = 0;
246 iface->transPtr = pmsg->buf;
247 iface->writeNum = iface->readNum = pmsg->len;
248 iface->result = 0;
249 iface->timeout_count = 10;
250 /* Set Transmit device address */
251 bfin_write_TWI_MASTER_ADDR(pmsg->addr);
252
253 /* FIFO Initiation. Data in FIFO should be
254 * discarded before start a new operation.
255 */
256 bfin_write_TWI_FIFO_CTL(0x3);
257 SSYNC();
258 bfin_write_TWI_FIFO_CTL(0);
259 SSYNC();
260
261 if (pmsg->flags & I2C_M_RD)
262 iface->read_write = I2C_SMBUS_READ;
263 else {
264 iface->read_write = I2C_SMBUS_WRITE;
265 /* Transmit first data */
266 if (iface->writeNum > 0) {
267 bfin_write_TWI_XMT_DATA8(*(iface->transPtr++));
268 iface->writeNum--;
269 SSYNC();
270 }
271 }
272
273 /* clear int stat */
274 bfin_write_TWI_INT_STAT(MERR|MCOMP|XMTSERV|RCVSERV);
275
276 /* Interrupt mask . Enable XMT, RCV interrupt */
277 bfin_write_TWI_INT_MASK(MCOMP | MERR |
278 ((iface->read_write == I2C_SMBUS_READ)?
279 RCVSERV : XMTSERV));
280 SSYNC();
281
282 if (pmsg->len > 0 && pmsg->len <= 255)
283 bfin_write_TWI_MASTER_CTL(pmsg->len << 6);
284 else if (pmsg->len > 255) {
285 bfin_write_TWI_MASTER_CTL(0xff << 6);
286 iface->manual_stop = 1;
287 } else
288 break;
289
290 iface->timeout_timer.expires = jiffies + POLL_TIMEOUT;
291 add_timer(&iface->timeout_timer);
292
293 /* Master enable */
294 bfin_write_TWI_MASTER_CTL(bfin_read_TWI_MASTER_CTL() | MEN |
295 ((iface->read_write == I2C_SMBUS_READ) ? MDIR : 0) |
296 ((CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ>100) ? FAST : 0));
297 SSYNC();
298
299 wait_for_completion(&iface->complete);
300
301 rc = iface->result;
302 if (rc == 1)
303 ret++;
304 else if (rc == -1)
305 break;
306 }
307
308 return ret;
309 }
310
311 /*
312 * SMBus type transfer entrypoint
313 */
314
315 int bfin_twi_smbus_xfer(struct i2c_adapter *adap, u16 addr,
316 unsigned short flags, char read_write,
317 u8 command, int size, union i2c_smbus_data *data)
318 {
319 struct bfin_twi_iface *iface = adap->algo_data;
320 int rc = 0;
321
322 if (!(bfin_read_TWI_CONTROL() & TWI_ENA))
323 return -ENXIO;
324
325 while (bfin_read_TWI_MASTER_STAT() & BUSBUSY) {
326 yield();
327 }
328
329 iface->writeNum = 0;
330 iface->readNum = 0;
331
332 /* Prepare datas & select mode */
333 switch (size) {
334 case I2C_SMBUS_QUICK:
335 iface->transPtr = NULL;
336 iface->cur_mode = TWI_I2C_MODE_STANDARD;
337 break;
338 case I2C_SMBUS_BYTE:
339 if (data == NULL)
340 iface->transPtr = NULL;
341 else {
342 if (read_write == I2C_SMBUS_READ)
343 iface->readNum = 1;
344 else
345 iface->writeNum = 1;
346 iface->transPtr = &data->byte;
347 }
348 iface->cur_mode = TWI_I2C_MODE_STANDARD;
349 break;
350 case I2C_SMBUS_BYTE_DATA:
351 if (read_write == I2C_SMBUS_READ) {
352 iface->readNum = 1;
353 iface->cur_mode = TWI_I2C_MODE_COMBINED;
354 } else {
355 iface->writeNum = 1;
356 iface->cur_mode = TWI_I2C_MODE_STANDARDSUB;
357 }
358 iface->transPtr = &data->byte;
359 break;
360 case I2C_SMBUS_WORD_DATA:
361 if (read_write == I2C_SMBUS_READ) {
362 iface->readNum = 2;
363 iface->cur_mode = TWI_I2C_MODE_COMBINED;
364 } else {
365 iface->writeNum = 2;
366 iface->cur_mode = TWI_I2C_MODE_STANDARDSUB;
367 }
368 iface->transPtr = (u8 *)&data->word;
369 break;
370 case I2C_SMBUS_PROC_CALL:
371 iface->writeNum = 2;
372 iface->readNum = 2;
373 iface->cur_mode = TWI_I2C_MODE_COMBINED;
374 iface->transPtr = (u8 *)&data->word;
375 break;
376 case I2C_SMBUS_BLOCK_DATA:
377 if (read_write == I2C_SMBUS_READ) {
378 iface->readNum = 0;
379 iface->cur_mode = TWI_I2C_MODE_COMBINED;
380 } else {
381 iface->writeNum = data->block[0] + 1;
382 iface->cur_mode = TWI_I2C_MODE_STANDARDSUB;
383 }
384 iface->transPtr = data->block;
385 break;
386 default:
387 return -1;
388 }
389
390 iface->result = 0;
391 iface->manual_stop = 0;
392 iface->read_write = read_write;
393 iface->command = command;
394 iface->timeout_count = 10;
395
396 /* FIFO Initiation. Data in FIFO should be discarded before
397 * start a new operation.
398 */
399 bfin_write_TWI_FIFO_CTL(0x3);
400 SSYNC();
401 bfin_write_TWI_FIFO_CTL(0);
402
403 /* clear int stat */
404 bfin_write_TWI_INT_STAT(MERR|MCOMP|XMTSERV|RCVSERV);
405
406 /* Set Transmit device address */
407 bfin_write_TWI_MASTER_ADDR(addr);
408 SSYNC();
409
410 iface->timeout_timer.expires = jiffies + POLL_TIMEOUT;
411 add_timer(&iface->timeout_timer);
412
413 switch (iface->cur_mode) {
414 case TWI_I2C_MODE_STANDARDSUB:
415 bfin_write_TWI_XMT_DATA8(iface->command);
416 bfin_write_TWI_INT_MASK(MCOMP | MERR |
417 ((iface->read_write == I2C_SMBUS_READ) ?
418 RCVSERV : XMTSERV));
419 SSYNC();
420
421 if (iface->writeNum + 1 <= 255)
422 bfin_write_TWI_MASTER_CTL((iface->writeNum + 1) << 6);
423 else {
424 bfin_write_TWI_MASTER_CTL(0xff << 6);
425 iface->manual_stop = 1;
426 }
427 /* Master enable */
428 bfin_write_TWI_MASTER_CTL(bfin_read_TWI_MASTER_CTL() | MEN |
429 ((CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ>100) ? FAST : 0));
430 break;
431 case TWI_I2C_MODE_COMBINED:
432 bfin_write_TWI_XMT_DATA8(iface->command);
433 bfin_write_TWI_INT_MASK(MCOMP | MERR | RCVSERV | XMTSERV);
434 SSYNC();
435
436 if (iface->writeNum > 0)
437 bfin_write_TWI_MASTER_CTL((iface->writeNum + 1) << 6);
438 else
439 bfin_write_TWI_MASTER_CTL(0x1 << 6);
440 /* Master enable */
441 bfin_write_TWI_MASTER_CTL(bfin_read_TWI_MASTER_CTL() | MEN |
442 ((CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ>100) ? FAST : 0));
443 break;
444 default:
445 bfin_write_TWI_MASTER_CTL(0);
446 if (size != I2C_SMBUS_QUICK) {
447 /* Don't access xmit data register when this is a
448 * read operation.
449 */
450 if (iface->read_write != I2C_SMBUS_READ) {
451 if (iface->writeNum > 0) {
452 bfin_write_TWI_XMT_DATA8(*(iface->transPtr++));
453 if (iface->writeNum <= 255)
454 bfin_write_TWI_MASTER_CTL(iface->writeNum << 6);
455 else {
456 bfin_write_TWI_MASTER_CTL(0xff << 6);
457 iface->manual_stop = 1;
458 }
459 iface->writeNum--;
460 } else {
461 bfin_write_TWI_XMT_DATA8(iface->command);
462 bfin_write_TWI_MASTER_CTL(1 << 6);
463 }
464 } else {
465 if (iface->readNum > 0 && iface->readNum <= 255)
466 bfin_write_TWI_MASTER_CTL(iface->readNum << 6);
467 else if (iface->readNum > 255) {
468 bfin_write_TWI_MASTER_CTL(0xff << 6);
469 iface->manual_stop = 1;
470 } else {
471 del_timer(&iface->timeout_timer);
472 break;
473 }
474 }
475 }
476 bfin_write_TWI_INT_MASK(MCOMP | MERR |
477 ((iface->read_write == I2C_SMBUS_READ) ?
478 RCVSERV : XMTSERV));
479 SSYNC();
480
481 /* Master enable */
482 bfin_write_TWI_MASTER_CTL(bfin_read_TWI_MASTER_CTL() | MEN |
483 ((iface->read_write == I2C_SMBUS_READ) ? MDIR : 0) |
484 ((CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ > 100) ? FAST : 0));
485 break;
486 }
487 SSYNC();
488
489 wait_for_completion(&iface->complete);
490
491 rc = (iface->result >= 0) ? 0 : -1;
492
493 return rc;
494 }
495
496 /*
497 * Return what the adapter supports
498 */
499 static u32 bfin_twi_functionality(struct i2c_adapter *adap)
500 {
501 return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
502 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
503 I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_PROC_CALL |
504 I2C_FUNC_I2C;
505 }
506
507
508 static struct i2c_algorithm bfin_twi_algorithm = {
509 .master_xfer = bfin_twi_master_xfer,
510 .smbus_xfer = bfin_twi_smbus_xfer,
511 .functionality = bfin_twi_functionality,
512 };
513
514
515 static int i2c_bfin_twi_suspend(struct platform_device *dev, pm_message_t state)
516 {
517 /* struct bfin_twi_iface *iface = platform_get_drvdata(dev);*/
518
519 /* Disable TWI */
520 bfin_write_TWI_CONTROL(bfin_read_TWI_CONTROL() & ~TWI_ENA);
521 SSYNC();
522
523 return 0;
524 }
525
526 static int i2c_bfin_twi_resume(struct platform_device *dev)
527 {
528 /* struct bfin_twi_iface *iface = platform_get_drvdata(dev);*/
529
530 /* Enable TWI */
531 bfin_write_TWI_CONTROL(bfin_read_TWI_CONTROL() | TWI_ENA);
532 SSYNC();
533
534 return 0;
535 }
536
537 static int i2c_bfin_twi_probe(struct platform_device *dev)
538 {
539 struct bfin_twi_iface *iface = &twi_iface;
540 struct i2c_adapter *p_adap;
541 int rc;
542
543 spin_lock_init(&(iface->lock));
544 init_completion(&(iface->complete));
545 iface->irq = IRQ_TWI;
546
547 init_timer(&(iface->timeout_timer));
548 iface->timeout_timer.function = bfin_twi_timeout;
549 iface->timeout_timer.data = (unsigned long)iface;
550
551 p_adap = &iface->adap;
552 p_adap->id = I2C_HW_BLACKFIN;
553 strlcpy(p_adap->name, dev->name, sizeof(p_adap->name));
554 p_adap->algo = &bfin_twi_algorithm;
555 p_adap->algo_data = iface;
556 p_adap->class = I2C_CLASS_ALL;
557 p_adap->dev.parent = &dev->dev;
558
559 rc = request_irq(iface->irq, bfin_twi_interrupt_entry,
560 IRQF_DISABLED, dev->name, iface);
561 if (rc) {
562 dev_err(&(p_adap->dev), "i2c-bfin-twi: can't get IRQ %d !\n",
563 iface->irq);
564 return -ENODEV;
565 }
566
567 /* Set TWI internal clock as 10MHz */
568 bfin_write_TWI_CONTROL(((get_sclk() / 1024 / 1024 + 5) / 10) & 0x7F);
569
570 /* Set Twi interface clock as specified */
571 bfin_write_TWI_CLKDIV((( 5*1024 / CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ )
572 << 8) | (( 5*1024 / CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ )
573 & 0xFF));
574
575 /* Enable TWI */
576 bfin_write_TWI_CONTROL(bfin_read_TWI_CONTROL() | TWI_ENA);
577 SSYNC();
578
579 rc = i2c_add_adapter(p_adap);
580 if (rc < 0)
581 free_irq(iface->irq, iface);
582 else
583 platform_set_drvdata(dev, iface);
584
585 return rc;
586 }
587
588 static int i2c_bfin_twi_remove(struct platform_device *pdev)
589 {
590 struct bfin_twi_iface *iface = platform_get_drvdata(pdev);
591
592 platform_set_drvdata(pdev, NULL);
593
594 i2c_del_adapter(&(iface->adap));
595 free_irq(iface->irq, iface);
596
597 return 0;
598 }
599
600 static struct platform_driver i2c_bfin_twi_driver = {
601 .probe = i2c_bfin_twi_probe,
602 .remove = i2c_bfin_twi_remove,
603 .suspend = i2c_bfin_twi_suspend,
604 .resume = i2c_bfin_twi_resume,
605 .driver = {
606 .name = "i2c-bfin-twi",
607 .owner = THIS_MODULE,
608 },
609 };
610
611 static int __init i2c_bfin_twi_init(void)
612 {
613 pr_info("I2C: Blackfin I2C TWI driver\n");
614
615 return platform_driver_register(&i2c_bfin_twi_driver);
616 }
617
618 static void __exit i2c_bfin_twi_exit(void)
619 {
620 platform_driver_unregister(&i2c_bfin_twi_driver);
621 }
622
623 MODULE_AUTHOR("Sonic Zhang <sonic.zhang@analog.com>");
624 MODULE_DESCRIPTION("I2C-Bus adapter routines for Blackfin TWI");
625 MODULE_LICENSE("GPL");
626
627 module_init(i2c_bfin_twi_init);
628 module_exit(i2c_bfin_twi_exit);
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