?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
MIPS: Yosemite, Emma: Fix off-by-two in arcs_cmdline buffer size check
[linux-2.6/linux-mips.git] / drivers / i2c / busses / i2c-bfin-twi.c
blobcdb59e5b23f749aa81153eb6619269d4f248eb61
1 /*
2 * Blackfin On-Chip Two Wire Interface Driver
3 *
4 * Copyright 2005-2007 Analog Devices Inc.
5 *
6 * Enter bugs at http://blackfin.uclinux.org/
7 *
8 * Licensed under the GPL-2 or later.
9 */
10
11 #include <linux/module.h>
12 #include <linux/kernel.h>
13 #include <linux/init.h>
14 #include <linux/i2c.h>
15 #include <linux/slab.h>
16 #include <linux/io.h>
17 #include <linux/mm.h>
18 #include <linux/timer.h>
19 #include <linux/spinlock.h>
20 #include <linux/completion.h>
21 #include <linux/interrupt.h>
22 #include <linux/platform_device.h>
23 #include <linux/delay.h>
24
25 #include <asm/blackfin.h>
26 #include <asm/portmux.h>
27 #include <asm/irq.h>
28
29 /* SMBus mode*/
30 #define TWI_I2C_MODE_STANDARD 1
31 #define TWI_I2C_MODE_STANDARDSUB 2
32 #define TWI_I2C_MODE_COMBINED 3
33 #define TWI_I2C_MODE_REPEAT 4
34
35 struct bfin_twi_iface {
36 int irq;
37 spinlock_t lock;
38 char read_write;
39 u8 command;
40 u8 *transPtr;
41 int readNum;
42 int writeNum;
43 int cur_mode;
44 int manual_stop;
45 int result;
46 struct i2c_adapter adap;
47 struct completion complete;
48 struct i2c_msg *pmsg;
49 int msg_num;
50 int cur_msg;
51 u16 saved_clkdiv;
52 u16 saved_control;
53 void __iomem *regs_base;
54 };
55
56
57 #define DEFINE_TWI_REG(reg, off) \
58 static inline u16 read_##reg(struct bfin_twi_iface *iface) \
59 { return bfin_read16(iface->regs_base + (off)); } \
60 static inline void write_##reg(struct bfin_twi_iface *iface, u16 v) \
61 { bfin_write16(iface->regs_base + (off), v); }
62
63 DEFINE_TWI_REG(CLKDIV, 0x00)
64 DEFINE_TWI_REG(CONTROL, 0x04)
65 DEFINE_TWI_REG(SLAVE_CTL, 0x08)
66 DEFINE_TWI_REG(SLAVE_STAT, 0x0C)
67 DEFINE_TWI_REG(SLAVE_ADDR, 0x10)
68 DEFINE_TWI_REG(MASTER_CTL, 0x14)
69 DEFINE_TWI_REG(MASTER_STAT, 0x18)
70 DEFINE_TWI_REG(MASTER_ADDR, 0x1C)
71 DEFINE_TWI_REG(INT_STAT, 0x20)
72 DEFINE_TWI_REG(INT_MASK, 0x24)
73 DEFINE_TWI_REG(FIFO_CTL, 0x28)
74 DEFINE_TWI_REG(FIFO_STAT, 0x2C)
75 DEFINE_TWI_REG(XMT_DATA8, 0x80)
76 DEFINE_TWI_REG(XMT_DATA16, 0x84)
77 DEFINE_TWI_REG(RCV_DATA8, 0x88)
78 DEFINE_TWI_REG(RCV_DATA16, 0x8C)
79
80 static const u16 pin_req[2][3] = {
81 {P_TWI0_SCL, P_TWI0_SDA, 0},
82 {P_TWI1_SCL, P_TWI1_SDA, 0},
83 };
84
85 static void bfin_twi_handle_interrupt(struct bfin_twi_iface *iface,
86 unsigned short twi_int_status)
87 {
88 unsigned short mast_stat = read_MASTER_STAT(iface);
89
90 if (twi_int_status & XMTSERV) {
91 /* Transmit next data */
92 if (iface->writeNum > 0) {
93 SSYNC();
94 write_XMT_DATA8(iface, *(iface->transPtr++));
95 iface->writeNum--;
96 }
97 /* start receive immediately after complete sending in
98 * combine mode.
99 */
100 else if (iface->cur_mode == TWI_I2C_MODE_COMBINED)
101 write_MASTER_CTL(iface,
102 read_MASTER_CTL(iface) | MDIR | RSTART);
103 else if (iface->manual_stop)
104 write_MASTER_CTL(iface,
105 read_MASTER_CTL(iface) | STOP);
106 else if (iface->cur_mode == TWI_I2C_MODE_REPEAT &&
107 iface->cur_msg + 1 < iface->msg_num) {
108 if (iface->pmsg[iface->cur_msg + 1].flags & I2C_M_RD)
109 write_MASTER_CTL(iface,
110 read_MASTER_CTL(iface) | RSTART | MDIR);
111 else
112 write_MASTER_CTL(iface,
113 (read_MASTER_CTL(iface) | RSTART) & ~MDIR);
114 }
115 }
116 if (twi_int_status & RCVSERV) {
117 if (iface->readNum > 0) {
118 /* Receive next data */
119 *(iface->transPtr) = read_RCV_DATA8(iface);
120 if (iface->cur_mode == TWI_I2C_MODE_COMBINED) {
121 /* Change combine mode into sub mode after
122 * read first data.
123 */
124 iface->cur_mode = TWI_I2C_MODE_STANDARDSUB;
125 /* Get read number from first byte in block
126 * combine mode.
127 */
128 if (iface->readNum == 1 && iface->manual_stop)
129 iface->readNum = *iface->transPtr + 1;
130 }
131 iface->transPtr++;
132 iface->readNum--;
133 } else if (iface->manual_stop) {
134 write_MASTER_CTL(iface,
135 read_MASTER_CTL(iface) | STOP);
136 } else if (iface->cur_mode == TWI_I2C_MODE_REPEAT &&
137 iface->cur_msg + 1 < iface->msg_num) {
138 if (iface->pmsg[iface->cur_msg + 1].flags & I2C_M_RD)
139 write_MASTER_CTL(iface,
140 read_MASTER_CTL(iface) | RSTART | MDIR);
141 else
142 write_MASTER_CTL(iface,
143 (read_MASTER_CTL(iface) | RSTART) & ~MDIR);
144 }
145 }
146 if (twi_int_status & MERR) {
147 write_INT_MASK(iface, 0);
148 write_MASTER_STAT(iface, 0x3e);
149 write_MASTER_CTL(iface, 0);
150 iface->result = -EIO;
151
152 if (mast_stat & LOSTARB)
153 dev_dbg(&iface->adap.dev, "Lost Arbitration\n");
154 if (mast_stat & ANAK)
155 dev_dbg(&iface->adap.dev, "Address Not Acknowledged\n");
156 if (mast_stat & DNAK)
157 dev_dbg(&iface->adap.dev, "Data Not Acknowledged\n");
158 if (mast_stat & BUFRDERR)
159 dev_dbg(&iface->adap.dev, "Buffer Read Error\n");
160 if (mast_stat & BUFWRERR)
161 dev_dbg(&iface->adap.dev, "Buffer Write Error\n");
162
163 /* Faulty slave devices, may drive SDA low after a transfer
164 * finishes. To release the bus this code generates up to 9
165 * extra clocks until SDA is released.
166 */
167
168 if (read_MASTER_STAT(iface) & SDASEN) {
169 int cnt = 9;
170 do {
171 write_MASTER_CTL(iface, SCLOVR);
172 udelay(6);
173 write_MASTER_CTL(iface, 0);
174 udelay(6);
175 } while ((read_MASTER_STAT(iface) & SDASEN) && cnt--);
176
177 write_MASTER_CTL(iface, SDAOVR | SCLOVR);
178 udelay(6);
179 write_MASTER_CTL(iface, SDAOVR);
180 udelay(6);
181 write_MASTER_CTL(iface, 0);
182 }
183
184 /* If it is a quick transfer, only address without data,
185 * not an err, return 1.
186 */
187 if (iface->cur_mode == TWI_I2C_MODE_STANDARD &&
188 iface->transPtr == NULL &&
189 (twi_int_status & MCOMP) && (mast_stat & DNAK))
190 iface->result = 1;
191
192 complete(&iface->complete);
193 return;
194 }
195 if (twi_int_status & MCOMP) {
196 if ((read_MASTER_CTL(iface) & MEN) == 0 &&
197 (iface->cur_mode == TWI_I2C_MODE_REPEAT ||
198 iface->cur_mode == TWI_I2C_MODE_COMBINED)) {
199 iface->result = -1;
200 write_INT_MASK(iface, 0);
201 write_MASTER_CTL(iface, 0);
202 } else if (iface->cur_mode == TWI_I2C_MODE_COMBINED) {
203 if (iface->readNum == 0) {
204 /* set the read number to 1 and ask for manual
205 * stop in block combine mode
206 */
207 iface->readNum = 1;
208 iface->manual_stop = 1;
209 write_MASTER_CTL(iface,
210 read_MASTER_CTL(iface) | (0xff << 6));
211 } else {
212 /* set the readd number in other
213 * combine mode.
214 */
215 write_MASTER_CTL(iface,
216 (read_MASTER_CTL(iface) &
217 (~(0xff << 6))) |
218 (iface->readNum << 6));
219 }
220 /* remove restart bit and enable master receive */
221 write_MASTER_CTL(iface,
222 read_MASTER_CTL(iface) & ~RSTART);
223 } else if (iface->cur_mode == TWI_I2C_MODE_REPEAT &&
224 iface->cur_msg+1 < iface->msg_num) {
225 iface->cur_msg++;
226 iface->transPtr = iface->pmsg[iface->cur_msg].buf;
227 iface->writeNum = iface->readNum =
228 iface->pmsg[iface->cur_msg].len;
229 /* Set Transmit device address */
230 write_MASTER_ADDR(iface,
231 iface->pmsg[iface->cur_msg].addr);
232 if (iface->pmsg[iface->cur_msg].flags & I2C_M_RD)
233 iface->read_write = I2C_SMBUS_READ;
234 else {
235 iface->read_write = I2C_SMBUS_WRITE;
236 /* Transmit first data */
237 if (iface->writeNum > 0) {
238 write_XMT_DATA8(iface,
239 *(iface->transPtr++));
240 iface->writeNum--;
241 }
242 }
243
244 if (iface->pmsg[iface->cur_msg].len <= 255)
245 write_MASTER_CTL(iface,
246 (read_MASTER_CTL(iface) &
247 (~(0xff << 6))) |
248 (iface->pmsg[iface->cur_msg].len << 6));
249 else {
250 write_MASTER_CTL(iface,
251 (read_MASTER_CTL(iface) |
252 (0xff << 6)));
253 iface->manual_stop = 1;
254 }
255 /* remove restart bit and enable master receive */
256 write_MASTER_CTL(iface,
257 read_MASTER_CTL(iface) & ~RSTART);
258 } else {
259 iface->result = 1;
260 write_INT_MASK(iface, 0);
261 write_MASTER_CTL(iface, 0);
262 }
263 }
264 complete(&iface->complete);
265 }
266
267 /* Interrupt handler */
268 static irqreturn_t bfin_twi_interrupt_entry(int irq, void *dev_id)
269 {
270 struct bfin_twi_iface *iface = dev_id;
271 unsigned long flags;
272 unsigned short twi_int_status;
273
274 spin_lock_irqsave(&iface->lock, flags);
275 while (1) {
276 twi_int_status = read_INT_STAT(iface);
277 if (!twi_int_status)
278 break;
279 /* Clear interrupt status */
280 write_INT_STAT(iface, twi_int_status);
281 bfin_twi_handle_interrupt(iface, twi_int_status);
282 SSYNC();
283 }
284 spin_unlock_irqrestore(&iface->lock, flags);
285 return IRQ_HANDLED;
286 }
287
288 /*
289 * One i2c master transfer
290 */
291 static int bfin_twi_do_master_xfer(struct i2c_adapter *adap,
292 struct i2c_msg *msgs, int num)
293 {
294 struct bfin_twi_iface *iface = adap->algo_data;
295 struct i2c_msg *pmsg;
296 int rc = 0;
297
298 if (!(read_CONTROL(iface) & TWI_ENA))
299 return -ENXIO;
300
301 while (read_MASTER_STAT(iface) & BUSBUSY)
302 yield();
303
304 iface->pmsg = msgs;
305 iface->msg_num = num;
306 iface->cur_msg = 0;
307
308 pmsg = &msgs[0];
309 if (pmsg->flags & I2C_M_TEN) {
310 dev_err(&adap->dev, "10 bits addr not supported!\n");
311 return -EINVAL;
312 }
313
314 iface->cur_mode = TWI_I2C_MODE_REPEAT;
315 iface->manual_stop = 0;
316 iface->transPtr = pmsg->buf;
317 iface->writeNum = iface->readNum = pmsg->len;
318 iface->result = 0;
319 init_completion(&(iface->complete));
320 /* Set Transmit device address */
321 write_MASTER_ADDR(iface, pmsg->addr);
322
323 /* FIFO Initiation. Data in FIFO should be
324 * discarded before start a new operation.
325 */
326 write_FIFO_CTL(iface, 0x3);
327 SSYNC();
328 write_FIFO_CTL(iface, 0);
329 SSYNC();
330
331 if (pmsg->flags & I2C_M_RD)
332 iface->read_write = I2C_SMBUS_READ;
333 else {
334 iface->read_write = I2C_SMBUS_WRITE;
335 /* Transmit first data */
336 if (iface->writeNum > 0) {
337 write_XMT_DATA8(iface, *(iface->transPtr++));
338 iface->writeNum--;
339 SSYNC();
340 }
341 }
342
343 /* clear int stat */
344 write_INT_STAT(iface, MERR | MCOMP | XMTSERV | RCVSERV);
345
346 /* Interrupt mask . Enable XMT, RCV interrupt */
347 write_INT_MASK(iface, MCOMP | MERR | RCVSERV | XMTSERV);
348 SSYNC();
349
350 if (pmsg->len <= 255)
351 write_MASTER_CTL(iface, pmsg->len << 6);
352 else {
353 write_MASTER_CTL(iface, 0xff << 6);
354 iface->manual_stop = 1;
355 }
356
357 /* Master enable */
358 write_MASTER_CTL(iface, read_MASTER_CTL(iface) | MEN |
359 ((iface->read_write == I2C_SMBUS_READ) ? MDIR : 0) |
360 ((CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ > 100) ? FAST : 0));
361 SSYNC();
362
363 while (!iface->result) {
364 if (!wait_for_completion_timeout(&iface->complete,
365 adap->timeout)) {
366 iface->result = -1;
367 dev_err(&adap->dev, "master transfer timeout\n");
368 }
369 }
370
371 if (iface->result == 1)
372 rc = iface->cur_msg + 1;
373 else
374 rc = iface->result;
375
376 return rc;
377 }
378
379 /*
380 * Generic i2c master transfer entrypoint
381 */
382 static int bfin_twi_master_xfer(struct i2c_adapter *adap,
383 struct i2c_msg *msgs, int num)
384 {
385 return bfin_twi_do_master_xfer(adap, msgs, num);
386 }
387
388 /*
389 * One I2C SMBus transfer
390 */
391 int bfin_twi_do_smbus_xfer(struct i2c_adapter *adap, u16 addr,
392 unsigned short flags, char read_write,
393 u8 command, int size, union i2c_smbus_data *data)
394 {
395 struct bfin_twi_iface *iface = adap->algo_data;
396 int rc = 0;
397
398 if (!(read_CONTROL(iface) & TWI_ENA))
399 return -ENXIO;
400
401 while (read_MASTER_STAT(iface) & BUSBUSY)
402 yield();
403
404 iface->writeNum = 0;
405 iface->readNum = 0;
406
407 /* Prepare datas & select mode */
408 switch (size) {
409 case I2C_SMBUS_QUICK:
410 iface->transPtr = NULL;
411 iface->cur_mode = TWI_I2C_MODE_STANDARD;
412 break;
413 case I2C_SMBUS_BYTE:
414 if (data == NULL)
415 iface->transPtr = NULL;
416 else {
417 if (read_write == I2C_SMBUS_READ)
418 iface->readNum = 1;
419 else
420 iface->writeNum = 1;
421 iface->transPtr = &data->byte;
422 }
423 iface->cur_mode = TWI_I2C_MODE_STANDARD;
424 break;
425 case I2C_SMBUS_BYTE_DATA:
426 if (read_write == I2C_SMBUS_READ) {
427 iface->readNum = 1;
428 iface->cur_mode = TWI_I2C_MODE_COMBINED;
429 } else {
430 iface->writeNum = 1;
431 iface->cur_mode = TWI_I2C_MODE_STANDARDSUB;
432 }
433 iface->transPtr = &data->byte;
434 break;
435 case I2C_SMBUS_WORD_DATA:
436 if (read_write == I2C_SMBUS_READ) {
437 iface->readNum = 2;
438 iface->cur_mode = TWI_I2C_MODE_COMBINED;
439 } else {
440 iface->writeNum = 2;
441 iface->cur_mode = TWI_I2C_MODE_STANDARDSUB;
442 }
443 iface->transPtr = (u8 *)&data->word;
444 break;
445 case I2C_SMBUS_PROC_CALL:
446 iface->writeNum = 2;
447 iface->readNum = 2;
448 iface->cur_mode = TWI_I2C_MODE_COMBINED;
449 iface->transPtr = (u8 *)&data->word;
450 break;
451 case I2C_SMBUS_BLOCK_DATA:
452 if (read_write == I2C_SMBUS_READ) {
453 iface->readNum = 0;
454 iface->cur_mode = TWI_I2C_MODE_COMBINED;
455 } else {
456 iface->writeNum = data->block[0] + 1;
457 iface->cur_mode = TWI_I2C_MODE_STANDARDSUB;
458 }
459 iface->transPtr = data->block;
460 break;
461 case I2C_SMBUS_I2C_BLOCK_DATA:
462 if (read_write == I2C_SMBUS_READ) {
463 iface->readNum = data->block[0];
464 iface->cur_mode = TWI_I2C_MODE_COMBINED;
465 } else {
466 iface->writeNum = data->block[0];
467 iface->cur_mode = TWI_I2C_MODE_STANDARDSUB;
468 }
469 iface->transPtr = (u8 *)&data->block[1];
470 break;
471 default:
472 return -1;
473 }
474
475 iface->result = 0;
476 iface->manual_stop = 0;
477 iface->read_write = read_write;
478 iface->command = command;
479 init_completion(&(iface->complete));
480
481 /* FIFO Initiation. Data in FIFO should be discarded before
482 * start a new operation.
483 */
484 write_FIFO_CTL(iface, 0x3);
485 SSYNC();
486 write_FIFO_CTL(iface, 0);
487
488 /* clear int stat */
489 write_INT_STAT(iface, MERR | MCOMP | XMTSERV | RCVSERV);
490
491 /* Set Transmit device address */
492 write_MASTER_ADDR(iface, addr);
493 SSYNC();
494
495 switch (iface->cur_mode) {
496 case TWI_I2C_MODE_STANDARDSUB:
497 write_XMT_DATA8(iface, iface->command);
498 write_INT_MASK(iface, MCOMP | MERR |
499 ((iface->read_write == I2C_SMBUS_READ) ?
500 RCVSERV : XMTSERV));
501 SSYNC();
502
503 if (iface->writeNum + 1 <= 255)
504 write_MASTER_CTL(iface, (iface->writeNum + 1) << 6);
505 else {
506 write_MASTER_CTL(iface, 0xff << 6);
507 iface->manual_stop = 1;
508 }
509 /* Master enable */
510 write_MASTER_CTL(iface, read_MASTER_CTL(iface) | MEN |
511 ((CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ>100) ? FAST : 0));
512 break;
513 case TWI_I2C_MODE_COMBINED:
514 write_XMT_DATA8(iface, iface->command);
515 write_INT_MASK(iface, MCOMP | MERR | RCVSERV | XMTSERV);
516 SSYNC();
517
518 if (iface->writeNum > 0)
519 write_MASTER_CTL(iface, (iface->writeNum + 1) << 6);
520 else
521 write_MASTER_CTL(iface, 0x1 << 6);
522 /* Master enable */
523 write_MASTER_CTL(iface, read_MASTER_CTL(iface) | MEN |
524 ((CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ>100) ? FAST : 0));
525 break;
526 default:
527 write_MASTER_CTL(iface, 0);
528 if (size != I2C_SMBUS_QUICK) {
529 /* Don't access xmit data register when this is a
530 * read operation.
531 */
532 if (iface->read_write != I2C_SMBUS_READ) {
533 if (iface->writeNum > 0) {
534 write_XMT_DATA8(iface,
535 *(iface->transPtr++));
536 if (iface->writeNum <= 255)
537 write_MASTER_CTL(iface,
538 iface->writeNum << 6);
539 else {
540 write_MASTER_CTL(iface,
541 0xff << 6);
542 iface->manual_stop = 1;
543 }
544 iface->writeNum--;
545 } else {
546 write_XMT_DATA8(iface, iface->command);
547 write_MASTER_CTL(iface, 1 << 6);
548 }
549 } else {
550 if (iface->readNum > 0 && iface->readNum <= 255)
551 write_MASTER_CTL(iface,
552 iface->readNum << 6);
553 else if (iface->readNum > 255) {
554 write_MASTER_CTL(iface, 0xff << 6);
555 iface->manual_stop = 1;
556 } else
557 break;
558 }
559 }
560 write_INT_MASK(iface, MCOMP | MERR |
561 ((iface->read_write == I2C_SMBUS_READ) ?
562 RCVSERV : XMTSERV));
563 SSYNC();
564
565 /* Master enable */
566 write_MASTER_CTL(iface, read_MASTER_CTL(iface) | MEN |
567 ((iface->read_write == I2C_SMBUS_READ) ? MDIR : 0) |
568 ((CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ > 100) ? FAST : 0));
569 break;
570 }
571 SSYNC();
572
573 while (!iface->result) {
574 if (!wait_for_completion_timeout(&iface->complete,
575 adap->timeout)) {
576 iface->result = -1;
577 dev_err(&adap->dev, "smbus transfer timeout\n");
578 }
579 }
580
581 rc = (iface->result >= 0) ? 0 : -1;
582
583 return rc;
584 }
585
586 /*
587 * Generic I2C SMBus transfer entrypoint
588 */
589 int bfin_twi_smbus_xfer(struct i2c_adapter *adap, u16 addr,
590 unsigned short flags, char read_write,
591 u8 command, int size, union i2c_smbus_data *data)
592 {
593 return bfin_twi_do_smbus_xfer(adap, addr, flags,
594 read_write, command, size, data);
595 }
596
597 /*
598 * Return what the adapter supports
599 */
600 static u32 bfin_twi_functionality(struct i2c_adapter *adap)
601 {
602 return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
603 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
604 I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_PROC_CALL |
605 I2C_FUNC_I2C | I2C_FUNC_SMBUS_I2C_BLOCK;
606 }
607
608 static struct i2c_algorithm bfin_twi_algorithm = {
609 .master_xfer = bfin_twi_master_xfer,
610 .smbus_xfer = bfin_twi_smbus_xfer,
611 .functionality = bfin_twi_functionality,
612 };
613
614 static int i2c_bfin_twi_suspend(struct platform_device *pdev, pm_message_t state)
615 {
616 struct bfin_twi_iface *iface = platform_get_drvdata(pdev);
617
618 iface->saved_clkdiv = read_CLKDIV(iface);
619 iface->saved_control = read_CONTROL(iface);
620
621 free_irq(iface->irq, iface);
622
623 /* Disable TWI */
624 write_CONTROL(iface, iface->saved_control & ~TWI_ENA);
625
626 return 0;
627 }
628
629 static int i2c_bfin_twi_resume(struct platform_device *pdev)
630 {
631 struct bfin_twi_iface *iface = platform_get_drvdata(pdev);
632
633 int rc = request_irq(iface->irq, bfin_twi_interrupt_entry,
634 0, pdev->name, iface);
635 if (rc) {
636 dev_err(&pdev->dev, "Can't get IRQ %d !\n", iface->irq);
637 return -ENODEV;
638 }
639
640 /* Resume TWI interface clock as specified */
641 write_CLKDIV(iface, iface->saved_clkdiv);
642
643 /* Resume TWI */
644 write_CONTROL(iface, iface->saved_control);
645
646 return 0;
647 }
648
649 static int i2c_bfin_twi_probe(struct platform_device *pdev)
650 {
651 struct bfin_twi_iface *iface;
652 struct i2c_adapter *p_adap;
653 struct resource *res;
654 int rc;
655 unsigned int clkhilow;
656
657 iface = kzalloc(sizeof(struct bfin_twi_iface), GFP_KERNEL);
658 if (!iface) {
659 dev_err(&pdev->dev, "Cannot allocate memory\n");
660 rc = -ENOMEM;
661 goto out_error_nomem;
662 }
663
664 spin_lock_init(&(iface->lock));
665
666 /* Find and map our resources */
667 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
668 if (res == NULL) {
669 dev_err(&pdev->dev, "Cannot get IORESOURCE_MEM\n");
670 rc = -ENOENT;
671 goto out_error_get_res;
672 }
673
674 iface->regs_base = ioremap(res->start, resource_size(res));
675 if (iface->regs_base == NULL) {
676 dev_err(&pdev->dev, "Cannot map IO\n");
677 rc = -ENXIO;
678 goto out_error_ioremap;
679 }
680
681 iface->irq = platform_get_irq(pdev, 0);
682 if (iface->irq < 0) {
683 dev_err(&pdev->dev, "No IRQ specified\n");
684 rc = -ENOENT;
685 goto out_error_no_irq;
686 }
687
688 p_adap = &iface->adap;
689 p_adap->nr = pdev->id;
690 strlcpy(p_adap->name, pdev->name, sizeof(p_adap->name));
691 p_adap->algo = &bfin_twi_algorithm;
692 p_adap->algo_data = iface;
693 p_adap->class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
694 p_adap->dev.parent = &pdev->dev;
695 p_adap->timeout = 5 * HZ;
696 p_adap->retries = 3;
697
698 rc = peripheral_request_list(pin_req[pdev->id], "i2c-bfin-twi");
699 if (rc) {
700 dev_err(&pdev->dev, "Can't setup pin mux!\n");
701 goto out_error_pin_mux;
702 }
703
704 rc = request_irq(iface->irq, bfin_twi_interrupt_entry,
705 0, pdev->name, iface);
706 if (rc) {
707 dev_err(&pdev->dev, "Can't get IRQ %d !\n", iface->irq);
708 rc = -ENODEV;
709 goto out_error_req_irq;
710 }
711
712 /* Set TWI internal clock as 10MHz */
713 write_CONTROL(iface, ((get_sclk() / 1000 / 1000 + 5) / 10) & 0x7F);
714
715 /*
716 * We will not end up with a CLKDIV=0 because no one will specify
717 * 20kHz SCL or less in Kconfig now. (5 * 1000 / 20 = 250)
718 */
719 clkhilow = ((10 * 1000 / CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ) + 1) / 2;
720
721 /* Set Twi interface clock as specified */
722 write_CLKDIV(iface, (clkhilow << 8) | clkhilow);
723
724 /* Enable TWI */
725 write_CONTROL(iface, read_CONTROL(iface) | TWI_ENA);
726 SSYNC();
727
728 rc = i2c_add_numbered_adapter(p_adap);
729 if (rc < 0) {
730 dev_err(&pdev->dev, "Can't add i2c adapter!\n");
731 goto out_error_add_adapter;
732 }
733
734 platform_set_drvdata(pdev, iface);
735
736 dev_info(&pdev->dev, "Blackfin BF5xx on-chip I2C TWI Contoller, "
737 "regs_base@%p\n", iface->regs_base);
738
739 return 0;
740
741 out_error_add_adapter:
742 free_irq(iface->irq, iface);
743 out_error_req_irq:
744 out_error_no_irq:
745 peripheral_free_list(pin_req[pdev->id]);
746 out_error_pin_mux:
747 iounmap(iface->regs_base);
748 out_error_ioremap:
749 out_error_get_res:
750 kfree(iface);
751 out_error_nomem:
752 return rc;
753 }
754
755 static int i2c_bfin_twi_remove(struct platform_device *pdev)
756 {
757 struct bfin_twi_iface *iface = platform_get_drvdata(pdev);
758
759 platform_set_drvdata(pdev, NULL);
760
761 i2c_del_adapter(&(iface->adap));
762 free_irq(iface->irq, iface);
763 peripheral_free_list(pin_req[pdev->id]);
764 iounmap(iface->regs_base);
765 kfree(iface);
766
767 return 0;
768 }
769
770 static struct platform_driver i2c_bfin_twi_driver = {
771 .probe = i2c_bfin_twi_probe,
772 .remove = i2c_bfin_twi_remove,
773 .suspend = i2c_bfin_twi_suspend,
774 .resume = i2c_bfin_twi_resume,
775 .driver = {
776 .name = "i2c-bfin-twi",
777 .owner = THIS_MODULE,
778 },
779 };
780
781 static int __init i2c_bfin_twi_init(void)
782 {
783 return platform_driver_register(&i2c_bfin_twi_driver);
784 }
785
786 static void __exit i2c_bfin_twi_exit(void)
787 {
788 platform_driver_unregister(&i2c_bfin_twi_driver);
789 }
790
791 subsys_initcall(i2c_bfin_twi_init);
792 module_exit(i2c_bfin_twi_exit);
793
794 MODULE_AUTHOR("Bryan Wu, Sonic Zhang");
795 MODULE_DESCRIPTION("Blackfin BF5xx on-chip I2C TWI Contoller Driver");
796 MODULE_LICENSE("GPL");
797 MODULE_ALIAS("platform:i2c-bfin-twi");
Mirror of the linux-mips.org kernel tree