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i2c-taos-evm: Fix log messages
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / i2c / busses / i2c-bfin-twi.c
blob52b545a795f2ae6e533bf0920385623e8e6e1b04
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 (iface->cur_mode == TWI_I2C_MODE_COMBINED) {
197 if (iface->readNum == 0) {
198 /* set the read number to 1 and ask for manual
199 * stop in block combine mode
200 */
201 iface->readNum = 1;
202 iface->manual_stop = 1;
203 write_MASTER_CTL(iface,
204 read_MASTER_CTL(iface) | (0xff << 6));
205 } else {
206 /* set the readd number in other
207 * combine mode.
208 */
209 write_MASTER_CTL(iface,
210 (read_MASTER_CTL(iface) &
211 (~(0xff << 6))) |
212 (iface->readNum << 6));
213 }
214 /* remove restart bit and enable master receive */
215 write_MASTER_CTL(iface,
216 read_MASTER_CTL(iface) & ~RSTART);
217 } else if (iface->cur_mode == TWI_I2C_MODE_REPEAT &&
218 iface->cur_msg+1 < iface->msg_num) {
219 iface->cur_msg++;
220 iface->transPtr = iface->pmsg[iface->cur_msg].buf;
221 iface->writeNum = iface->readNum =
222 iface->pmsg[iface->cur_msg].len;
223 /* Set Transmit device address */
224 write_MASTER_ADDR(iface,
225 iface->pmsg[iface->cur_msg].addr);
226 if (iface->pmsg[iface->cur_msg].flags & I2C_M_RD)
227 iface->read_write = I2C_SMBUS_READ;
228 else {
229 iface->read_write = I2C_SMBUS_WRITE;
230 /* Transmit first data */
231 if (iface->writeNum > 0) {
232 write_XMT_DATA8(iface,
233 *(iface->transPtr++));
234 iface->writeNum--;
235 }
236 }
237
238 if (iface->pmsg[iface->cur_msg].len <= 255)
239 write_MASTER_CTL(iface,
240 (read_MASTER_CTL(iface) &
241 (~(0xff << 6))) |
242 (iface->pmsg[iface->cur_msg].len << 6));
243 else {
244 write_MASTER_CTL(iface,
245 (read_MASTER_CTL(iface) |
246 (0xff << 6)));
247 iface->manual_stop = 1;
248 }
249 /* remove restart bit and enable master receive */
250 write_MASTER_CTL(iface,
251 read_MASTER_CTL(iface) & ~RSTART);
252 } else {
253 iface->result = 1;
254 write_INT_MASK(iface, 0);
255 write_MASTER_CTL(iface, 0);
256 }
257 }
258 complete(&iface->complete);
259 }
260
261 /* Interrupt handler */
262 static irqreturn_t bfin_twi_interrupt_entry(int irq, void *dev_id)
263 {
264 struct bfin_twi_iface *iface = dev_id;
265 unsigned long flags;
266 unsigned short twi_int_status;
267
268 spin_lock_irqsave(&iface->lock, flags);
269 while (1) {
270 twi_int_status = read_INT_STAT(iface);
271 if (!twi_int_status)
272 break;
273 /* Clear interrupt status */
274 write_INT_STAT(iface, twi_int_status);
275 bfin_twi_handle_interrupt(iface, twi_int_status);
276 SSYNC();
277 }
278 spin_unlock_irqrestore(&iface->lock, flags);
279 return IRQ_HANDLED;
280 }
281
282 /*
283 * One i2c master transfer
284 */
285 static int bfin_twi_do_master_xfer(struct i2c_adapter *adap,
286 struct i2c_msg *msgs, int num)
287 {
288 struct bfin_twi_iface *iface = adap->algo_data;
289 struct i2c_msg *pmsg;
290 int rc = 0;
291
292 if (!(read_CONTROL(iface) & TWI_ENA))
293 return -ENXIO;
294
295 while (read_MASTER_STAT(iface) & BUSBUSY)
296 yield();
297
298 iface->pmsg = msgs;
299 iface->msg_num = num;
300 iface->cur_msg = 0;
301
302 pmsg = &msgs[0];
303 if (pmsg->flags & I2C_M_TEN) {
304 dev_err(&adap->dev, "10 bits addr not supported!\n");
305 return -EINVAL;
306 }
307
308 iface->cur_mode = TWI_I2C_MODE_REPEAT;
309 iface->manual_stop = 0;
310 iface->transPtr = pmsg->buf;
311 iface->writeNum = iface->readNum = pmsg->len;
312 iface->result = 0;
313 init_completion(&(iface->complete));
314 /* Set Transmit device address */
315 write_MASTER_ADDR(iface, pmsg->addr);
316
317 /* FIFO Initiation. Data in FIFO should be
318 * discarded before start a new operation.
319 */
320 write_FIFO_CTL(iface, 0x3);
321 SSYNC();
322 write_FIFO_CTL(iface, 0);
323 SSYNC();
324
325 if (pmsg->flags & I2C_M_RD)
326 iface->read_write = I2C_SMBUS_READ;
327 else {
328 iface->read_write = I2C_SMBUS_WRITE;
329 /* Transmit first data */
330 if (iface->writeNum > 0) {
331 write_XMT_DATA8(iface, *(iface->transPtr++));
332 iface->writeNum--;
333 SSYNC();
334 }
335 }
336
337 /* clear int stat */
338 write_INT_STAT(iface, MERR | MCOMP | XMTSERV | RCVSERV);
339
340 /* Interrupt mask . Enable XMT, RCV interrupt */
341 write_INT_MASK(iface, MCOMP | MERR | RCVSERV | XMTSERV);
342 SSYNC();
343
344 if (pmsg->len <= 255)
345 write_MASTER_CTL(iface, pmsg->len << 6);
346 else {
347 write_MASTER_CTL(iface, 0xff << 6);
348 iface->manual_stop = 1;
349 }
350
351 /* Master enable */
352 write_MASTER_CTL(iface, read_MASTER_CTL(iface) | MEN |
353 ((iface->read_write == I2C_SMBUS_READ) ? MDIR : 0) |
354 ((CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ > 100) ? FAST : 0));
355 SSYNC();
356
357 while (!iface->result) {
358 if (!wait_for_completion_timeout(&iface->complete,
359 adap->timeout)) {
360 iface->result = -1;
361 dev_err(&adap->dev, "master transfer timeout\n");
362 }
363 }
364
365 if (iface->result == 1)
366 rc = iface->cur_msg + 1;
367 else
368 rc = iface->result;
369
370 return rc;
371 }
372
373 /*
374 * Generic i2c master transfer entrypoint
375 */
376 static int bfin_twi_master_xfer(struct i2c_adapter *adap,
377 struct i2c_msg *msgs, int num)
378 {
379 return bfin_twi_do_master_xfer(adap, msgs, num);
380 }
381
382 /*
383 * One I2C SMBus transfer
384 */
385 int bfin_twi_do_smbus_xfer(struct i2c_adapter *adap, u16 addr,
386 unsigned short flags, char read_write,
387 u8 command, int size, union i2c_smbus_data *data)
388 {
389 struct bfin_twi_iface *iface = adap->algo_data;
390 int rc = 0;
391
392 if (!(read_CONTROL(iface) & TWI_ENA))
393 return -ENXIO;
394
395 while (read_MASTER_STAT(iface) & BUSBUSY)
396 yield();
397
398 iface->writeNum = 0;
399 iface->readNum = 0;
400
401 /* Prepare datas & select mode */
402 switch (size) {
403 case I2C_SMBUS_QUICK:
404 iface->transPtr = NULL;
405 iface->cur_mode = TWI_I2C_MODE_STANDARD;
406 break;
407 case I2C_SMBUS_BYTE:
408 if (data == NULL)
409 iface->transPtr = NULL;
410 else {
411 if (read_write == I2C_SMBUS_READ)
412 iface->readNum = 1;
413 else
414 iface->writeNum = 1;
415 iface->transPtr = &data->byte;
416 }
417 iface->cur_mode = TWI_I2C_MODE_STANDARD;
418 break;
419 case I2C_SMBUS_BYTE_DATA:
420 if (read_write == I2C_SMBUS_READ) {
421 iface->readNum = 1;
422 iface->cur_mode = TWI_I2C_MODE_COMBINED;
423 } else {
424 iface->writeNum = 1;
425 iface->cur_mode = TWI_I2C_MODE_STANDARDSUB;
426 }
427 iface->transPtr = &data->byte;
428 break;
429 case I2C_SMBUS_WORD_DATA:
430 if (read_write == I2C_SMBUS_READ) {
431 iface->readNum = 2;
432 iface->cur_mode = TWI_I2C_MODE_COMBINED;
433 } else {
434 iface->writeNum = 2;
435 iface->cur_mode = TWI_I2C_MODE_STANDARDSUB;
436 }
437 iface->transPtr = (u8 *)&data->word;
438 break;
439 case I2C_SMBUS_PROC_CALL:
440 iface->writeNum = 2;
441 iface->readNum = 2;
442 iface->cur_mode = TWI_I2C_MODE_COMBINED;
443 iface->transPtr = (u8 *)&data->word;
444 break;
445 case I2C_SMBUS_BLOCK_DATA:
446 if (read_write == I2C_SMBUS_READ) {
447 iface->readNum = 0;
448 iface->cur_mode = TWI_I2C_MODE_COMBINED;
449 } else {
450 iface->writeNum = data->block[0] + 1;
451 iface->cur_mode = TWI_I2C_MODE_STANDARDSUB;
452 }
453 iface->transPtr = data->block;
454 break;
455 case I2C_SMBUS_I2C_BLOCK_DATA:
456 if (read_write == I2C_SMBUS_READ) {
457 iface->readNum = data->block[0];
458 iface->cur_mode = TWI_I2C_MODE_COMBINED;
459 } else {
460 iface->writeNum = data->block[0];
461 iface->cur_mode = TWI_I2C_MODE_STANDARDSUB;
462 }
463 iface->transPtr = (u8 *)&data->block[1];
464 break;
465 default:
466 return -1;
467 }
468
469 iface->result = 0;
470 iface->manual_stop = 0;
471 iface->read_write = read_write;
472 iface->command = command;
473 init_completion(&(iface->complete));
474
475 /* FIFO Initiation. Data in FIFO should be discarded before
476 * start a new operation.
477 */
478 write_FIFO_CTL(iface, 0x3);
479 SSYNC();
480 write_FIFO_CTL(iface, 0);
481
482 /* clear int stat */
483 write_INT_STAT(iface, MERR | MCOMP | XMTSERV | RCVSERV);
484
485 /* Set Transmit device address */
486 write_MASTER_ADDR(iface, addr);
487 SSYNC();
488
489 switch (iface->cur_mode) {
490 case TWI_I2C_MODE_STANDARDSUB:
491 write_XMT_DATA8(iface, iface->command);
492 write_INT_MASK(iface, MCOMP | MERR |
493 ((iface->read_write == I2C_SMBUS_READ) ?
494 RCVSERV : XMTSERV));
495 SSYNC();
496
497 if (iface->writeNum + 1 <= 255)
498 write_MASTER_CTL(iface, (iface->writeNum + 1) << 6);
499 else {
500 write_MASTER_CTL(iface, 0xff << 6);
501 iface->manual_stop = 1;
502 }
503 /* Master enable */
504 write_MASTER_CTL(iface, read_MASTER_CTL(iface) | MEN |
505 ((CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ>100) ? FAST : 0));
506 break;
507 case TWI_I2C_MODE_COMBINED:
508 write_XMT_DATA8(iface, iface->command);
509 write_INT_MASK(iface, MCOMP | MERR | RCVSERV | XMTSERV);
510 SSYNC();
511
512 if (iface->writeNum > 0)
513 write_MASTER_CTL(iface, (iface->writeNum + 1) << 6);
514 else
515 write_MASTER_CTL(iface, 0x1 << 6);
516 /* Master enable */
517 write_MASTER_CTL(iface, read_MASTER_CTL(iface) | MEN |
518 ((CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ>100) ? FAST : 0));
519 break;
520 default:
521 write_MASTER_CTL(iface, 0);
522 if (size != I2C_SMBUS_QUICK) {
523 /* Don't access xmit data register when this is a
524 * read operation.
525 */
526 if (iface->read_write != I2C_SMBUS_READ) {
527 if (iface->writeNum > 0) {
528 write_XMT_DATA8(iface,
529 *(iface->transPtr++));
530 if (iface->writeNum <= 255)
531 write_MASTER_CTL(iface,
532 iface->writeNum << 6);
533 else {
534 write_MASTER_CTL(iface,
535 0xff << 6);
536 iface->manual_stop = 1;
537 }
538 iface->writeNum--;
539 } else {
540 write_XMT_DATA8(iface, iface->command);
541 write_MASTER_CTL(iface, 1 << 6);
542 }
543 } else {
544 if (iface->readNum > 0 && iface->readNum <= 255)
545 write_MASTER_CTL(iface,
546 iface->readNum << 6);
547 else if (iface->readNum > 255) {
548 write_MASTER_CTL(iface, 0xff << 6);
549 iface->manual_stop = 1;
550 } else
551 break;
552 }
553 }
554 write_INT_MASK(iface, MCOMP | MERR |
555 ((iface->read_write == I2C_SMBUS_READ) ?
556 RCVSERV : XMTSERV));
557 SSYNC();
558
559 /* Master enable */
560 write_MASTER_CTL(iface, read_MASTER_CTL(iface) | MEN |
561 ((iface->read_write == I2C_SMBUS_READ) ? MDIR : 0) |
562 ((CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ > 100) ? FAST : 0));
563 break;
564 }
565 SSYNC();
566
567 while (!iface->result) {
568 if (!wait_for_completion_timeout(&iface->complete,
569 adap->timeout)) {
570 iface->result = -1;
571 dev_err(&adap->dev, "smbus transfer timeout\n");
572 }
573 }
574
575 rc = (iface->result >= 0) ? 0 : -1;
576
577 return rc;
578 }
579
580 /*
581 * Generic I2C SMBus transfer entrypoint
582 */
583 int bfin_twi_smbus_xfer(struct i2c_adapter *adap, u16 addr,
584 unsigned short flags, char read_write,
585 u8 command, int size, union i2c_smbus_data *data)
586 {
587 return bfin_twi_do_smbus_xfer(adap, addr, flags,
588 read_write, command, size, data);
589 }
590
591 /*
592 * Return what the adapter supports
593 */
594 static u32 bfin_twi_functionality(struct i2c_adapter *adap)
595 {
596 return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
597 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
598 I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_PROC_CALL |
599 I2C_FUNC_I2C | I2C_FUNC_SMBUS_I2C_BLOCK;
600 }
601
602 static struct i2c_algorithm bfin_twi_algorithm = {
603 .master_xfer = bfin_twi_master_xfer,
604 .smbus_xfer = bfin_twi_smbus_xfer,
605 .functionality = bfin_twi_functionality,
606 };
607
608 static int i2c_bfin_twi_suspend(struct platform_device *pdev, pm_message_t state)
609 {
610 struct bfin_twi_iface *iface = platform_get_drvdata(pdev);
611
612 iface->saved_clkdiv = read_CLKDIV(iface);
613 iface->saved_control = read_CONTROL(iface);
614
615 free_irq(iface->irq, iface);
616
617 /* Disable TWI */
618 write_CONTROL(iface, iface->saved_control & ~TWI_ENA);
619
620 return 0;
621 }
622
623 static int i2c_bfin_twi_resume(struct platform_device *pdev)
624 {
625 struct bfin_twi_iface *iface = platform_get_drvdata(pdev);
626
627 int rc = request_irq(iface->irq, bfin_twi_interrupt_entry,
628 IRQF_DISABLED, pdev->name, iface);
629 if (rc) {
630 dev_err(&pdev->dev, "Can't get IRQ %d !\n", iface->irq);
631 return -ENODEV;
632 }
633
634 /* Resume TWI interface clock as specified */
635 write_CLKDIV(iface, iface->saved_clkdiv);
636
637 /* Resume TWI */
638 write_CONTROL(iface, iface->saved_control);
639
640 return 0;
641 }
642
643 static int i2c_bfin_twi_probe(struct platform_device *pdev)
644 {
645 struct bfin_twi_iface *iface;
646 struct i2c_adapter *p_adap;
647 struct resource *res;
648 int rc;
649 unsigned int clkhilow;
650
651 iface = kzalloc(sizeof(struct bfin_twi_iface), GFP_KERNEL);
652 if (!iface) {
653 dev_err(&pdev->dev, "Cannot allocate memory\n");
654 rc = -ENOMEM;
655 goto out_error_nomem;
656 }
657
658 spin_lock_init(&(iface->lock));
659
660 /* Find and map our resources */
661 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
662 if (res == NULL) {
663 dev_err(&pdev->dev, "Cannot get IORESOURCE_MEM\n");
664 rc = -ENOENT;
665 goto out_error_get_res;
666 }
667
668 iface->regs_base = ioremap(res->start, resource_size(res));
669 if (iface->regs_base == NULL) {
670 dev_err(&pdev->dev, "Cannot map IO\n");
671 rc = -ENXIO;
672 goto out_error_ioremap;
673 }
674
675 iface->irq = platform_get_irq(pdev, 0);
676 if (iface->irq < 0) {
677 dev_err(&pdev->dev, "No IRQ specified\n");
678 rc = -ENOENT;
679 goto out_error_no_irq;
680 }
681
682 p_adap = &iface->adap;
683 p_adap->nr = pdev->id;
684 strlcpy(p_adap->name, pdev->name, sizeof(p_adap->name));
685 p_adap->algo = &bfin_twi_algorithm;
686 p_adap->algo_data = iface;
687 p_adap->class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
688 p_adap->dev.parent = &pdev->dev;
689 p_adap->timeout = 5 * HZ;
690 p_adap->retries = 3;
691
692 rc = peripheral_request_list(pin_req[pdev->id], "i2c-bfin-twi");
693 if (rc) {
694 dev_err(&pdev->dev, "Can't setup pin mux!\n");
695 goto out_error_pin_mux;
696 }
697
698 rc = request_irq(iface->irq, bfin_twi_interrupt_entry,
699 IRQF_DISABLED, pdev->name, iface);
700 if (rc) {
701 dev_err(&pdev->dev, "Can't get IRQ %d !\n", iface->irq);
702 rc = -ENODEV;
703 goto out_error_req_irq;
704 }
705
706 /* Set TWI internal clock as 10MHz */
707 write_CONTROL(iface, ((get_sclk() / 1000 / 1000 + 5) / 10) & 0x7F);
708
709 /*
710 * We will not end up with a CLKDIV=0 because no one will specify
711 * 20kHz SCL or less in Kconfig now. (5 * 1000 / 20 = 250)
712 */
713 clkhilow = ((10 * 1000 / CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ) + 1) / 2;
714
715 /* Set Twi interface clock as specified */
716 write_CLKDIV(iface, (clkhilow << 8) | clkhilow);
717
718 /* Enable TWI */
719 write_CONTROL(iface, read_CONTROL(iface) | TWI_ENA);
720 SSYNC();
721
722 rc = i2c_add_numbered_adapter(p_adap);
723 if (rc < 0) {
724 dev_err(&pdev->dev, "Can't add i2c adapter!\n");
725 goto out_error_add_adapter;
726 }
727
728 platform_set_drvdata(pdev, iface);
729
730 dev_info(&pdev->dev, "Blackfin BF5xx on-chip I2C TWI Contoller, "
731 "regs_base@%p\n", iface->regs_base);
732
733 return 0;
734
735 out_error_add_adapter:
736 free_irq(iface->irq, iface);
737 out_error_req_irq:
738 out_error_no_irq:
739 peripheral_free_list(pin_req[pdev->id]);
740 out_error_pin_mux:
741 iounmap(iface->regs_base);
742 out_error_ioremap:
743 out_error_get_res:
744 kfree(iface);
745 out_error_nomem:
746 return rc;
747 }
748
749 static int i2c_bfin_twi_remove(struct platform_device *pdev)
750 {
751 struct bfin_twi_iface *iface = platform_get_drvdata(pdev);
752
753 platform_set_drvdata(pdev, NULL);
754
755 i2c_del_adapter(&(iface->adap));
756 free_irq(iface->irq, iface);
757 peripheral_free_list(pin_req[pdev->id]);
758 iounmap(iface->regs_base);
759 kfree(iface);
760
761 return 0;
762 }
763
764 static struct platform_driver i2c_bfin_twi_driver = {
765 .probe = i2c_bfin_twi_probe,
766 .remove = i2c_bfin_twi_remove,
767 .suspend = i2c_bfin_twi_suspend,
768 .resume = i2c_bfin_twi_resume,
769 .driver = {
770 .name = "i2c-bfin-twi",
771 .owner = THIS_MODULE,
772 },
773 };
774
775 static int __init i2c_bfin_twi_init(void)
776 {
777 return platform_driver_register(&i2c_bfin_twi_driver);
778 }
779
780 static void __exit i2c_bfin_twi_exit(void)
781 {
782 platform_driver_unregister(&i2c_bfin_twi_driver);
783 }
784
785 subsys_initcall(i2c_bfin_twi_init);
786 module_exit(i2c_bfin_twi_exit);
787
788 MODULE_AUTHOR("Bryan Wu, Sonic Zhang");
789 MODULE_DESCRIPTION("Blackfin BF5xx on-chip I2C TWI Contoller Driver");
790 MODULE_LICENSE("GPL");
791 MODULE_ALIAS("platform:i2c-bfin-twi");
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree