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12#include <linux/kernel.h>
13#include <linux/module.h>
14#include <linux/spinlock.h>
15#include <linux/i2c.h>
16#include <linux/interrupt.h>
17#include <linux/mv643xx_i2c.h>
18#include <linux/platform_device.h>
19
20#include <asm/io.h>
21
22
23#define MV64XXX_I2C_REG_SLAVE_ADDR 0x00
24#define MV64XXX_I2C_REG_DATA 0x04
25#define MV64XXX_I2C_REG_CONTROL 0x08
26#define MV64XXX_I2C_REG_STATUS 0x0c
27#define MV64XXX_I2C_REG_BAUD 0x0c
28#define MV64XXX_I2C_REG_EXT_SLAVE_ADDR 0x10
29#define MV64XXX_I2C_REG_SOFT_RESET 0x1c
30
31#define MV64XXX_I2C_REG_CONTROL_ACK 0x00000004
32#define MV64XXX_I2C_REG_CONTROL_IFLG 0x00000008
33#define MV64XXX_I2C_REG_CONTROL_STOP 0x00000010
34#define MV64XXX_I2C_REG_CONTROL_START 0x00000020
35#define MV64XXX_I2C_REG_CONTROL_TWSIEN 0x00000040
36#define MV64XXX_I2C_REG_CONTROL_INTEN 0x00000080
37
38
39#define MV64XXX_I2C_STATUS_BUS_ERR 0x00
40#define MV64XXX_I2C_STATUS_MAST_START 0x08
41#define MV64XXX_I2C_STATUS_MAST_REPEAT_START 0x10
42#define MV64XXX_I2C_STATUS_MAST_WR_ADDR_ACK 0x18
43#define MV64XXX_I2C_STATUS_MAST_WR_ADDR_NO_ACK 0x20
44#define MV64XXX_I2C_STATUS_MAST_WR_ACK 0x28
45#define MV64XXX_I2C_STATUS_MAST_WR_NO_ACK 0x30
46#define MV64XXX_I2C_STATUS_MAST_LOST_ARB 0x38
47#define MV64XXX_I2C_STATUS_MAST_RD_ADDR_ACK 0x40
48#define MV64XXX_I2C_STATUS_MAST_RD_ADDR_NO_ACK 0x48
49#define MV64XXX_I2C_STATUS_MAST_RD_DATA_ACK 0x50
50#define MV64XXX_I2C_STATUS_MAST_RD_DATA_NO_ACK 0x58
51#define MV64XXX_I2C_STATUS_MAST_WR_ADDR_2_ACK 0xd0
52#define MV64XXX_I2C_STATUS_MAST_WR_ADDR_2_NO_ACK 0xd8
53#define MV64XXX_I2C_STATUS_MAST_RD_ADDR_2_ACK 0xe0
54#define MV64XXX_I2C_STATUS_MAST_RD_ADDR_2_NO_ACK 0xe8
55#define MV64XXX_I2C_STATUS_NO_STATUS 0xf8
56
57
58enum {
59 MV64XXX_I2C_STATE_INVALID,
60 MV64XXX_I2C_STATE_IDLE,
61 MV64XXX_I2C_STATE_WAITING_FOR_START_COND,
62 MV64XXX_I2C_STATE_WAITING_FOR_ADDR_1_ACK,
63 MV64XXX_I2C_STATE_WAITING_FOR_ADDR_2_ACK,
64 MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_ACK,
65 MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_DATA,
66};
67
68
69enum {
70 MV64XXX_I2C_ACTION_INVALID,
71 MV64XXX_I2C_ACTION_CONTINUE,
72 MV64XXX_I2C_ACTION_SEND_START,
73 MV64XXX_I2C_ACTION_SEND_ADDR_1,
74 MV64XXX_I2C_ACTION_SEND_ADDR_2,
75 MV64XXX_I2C_ACTION_SEND_DATA,
76 MV64XXX_I2C_ACTION_RCV_DATA,
77 MV64XXX_I2C_ACTION_RCV_DATA_STOP,
78 MV64XXX_I2C_ACTION_SEND_STOP,
79};
80
81struct mv64xxx_i2c_data {
82 int irq;
83 u32 state;
84 u32 action;
85 u32 aborting;
86 u32 cntl_bits;
87 void __iomem *reg_base;
88 u32 reg_base_p;
89 u32 reg_size;
90 u32 addr1;
91 u32 addr2;
92 u32 bytes_left;
93 u32 byte_posn;
94 u32 block;
95 int rc;
96 u32 freq_m;
97 u32 freq_n;
98 wait_queue_head_t waitq;
99 spinlock_t lock;
100 struct i2c_msg *msg;
101 struct i2c_adapter adapter;
102};
103
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110
111
112
113static void
114mv64xxx_i2c_hw_init(struct mv64xxx_i2c_data *drv_data)
115{
116 writel(0, drv_data->reg_base + MV64XXX_I2C_REG_SOFT_RESET);
117 writel((((drv_data->freq_m & 0xf) << 3) | (drv_data->freq_n & 0x7)),
118 drv_data->reg_base + MV64XXX_I2C_REG_BAUD);
119 writel(0, drv_data->reg_base + MV64XXX_I2C_REG_SLAVE_ADDR);
120 writel(0, drv_data->reg_base + MV64XXX_I2C_REG_EXT_SLAVE_ADDR);
121 writel(MV64XXX_I2C_REG_CONTROL_TWSIEN | MV64XXX_I2C_REG_CONTROL_STOP,
122 drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
123 drv_data->state = MV64XXX_I2C_STATE_IDLE;
124}
125
126static void
127mv64xxx_i2c_fsm(struct mv64xxx_i2c_data *drv_data, u32 status)
128{
129
130
131
132
133
134 if (drv_data->state == MV64XXX_I2C_STATE_IDLE) {
135 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
136 return;
137 }
138
139
140 switch (status) {
141
142 case MV64XXX_I2C_STATUS_MAST_START:
143 case MV64XXX_I2C_STATUS_MAST_REPEAT_START:
144 drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_1;
145 drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_ADDR_1_ACK;
146 break;
147
148
149 case MV64XXX_I2C_STATUS_MAST_WR_ADDR_ACK:
150 if (drv_data->msg->flags & I2C_M_TEN) {
151 drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_2;
152 drv_data->state =
153 MV64XXX_I2C_STATE_WAITING_FOR_ADDR_2_ACK;
154 break;
155 }
156
157 case MV64XXX_I2C_STATUS_MAST_WR_ADDR_2_ACK:
158 case MV64XXX_I2C_STATUS_MAST_WR_ACK:
159 if ((drv_data->bytes_left == 0)
160 || (drv_data->aborting
161 && (drv_data->byte_posn != 0))) {
162 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
163 drv_data->state = MV64XXX_I2C_STATE_IDLE;
164 } else {
165 drv_data->action = MV64XXX_I2C_ACTION_SEND_DATA;
166 drv_data->state =
167 MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_ACK;
168 drv_data->bytes_left--;
169 }
170 break;
171
172
173 case MV64XXX_I2C_STATUS_MAST_RD_ADDR_ACK:
174 if (drv_data->msg->flags & I2C_M_TEN) {
175 drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_2;
176 drv_data->state =
177 MV64XXX_I2C_STATE_WAITING_FOR_ADDR_2_ACK;
178 break;
179 }
180
181 case MV64XXX_I2C_STATUS_MAST_RD_ADDR_2_ACK:
182 if (drv_data->bytes_left == 0) {
183 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
184 drv_data->state = MV64XXX_I2C_STATE_IDLE;
185 break;
186 }
187
188 case MV64XXX_I2C_STATUS_MAST_RD_DATA_ACK:
189 if (status != MV64XXX_I2C_STATUS_MAST_RD_DATA_ACK)
190 drv_data->action = MV64XXX_I2C_ACTION_CONTINUE;
191 else {
192 drv_data->action = MV64XXX_I2C_ACTION_RCV_DATA;
193 drv_data->bytes_left--;
194 }
195 drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_DATA;
196
197 if ((drv_data->bytes_left == 1) || drv_data->aborting)
198 drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_ACK;
199 break;
200
201 case MV64XXX_I2C_STATUS_MAST_RD_DATA_NO_ACK:
202 drv_data->action = MV64XXX_I2C_ACTION_RCV_DATA_STOP;
203 drv_data->state = MV64XXX_I2C_STATE_IDLE;
204 break;
205
206 case MV64XXX_I2C_STATUS_MAST_WR_ADDR_NO_ACK:
207 case MV64XXX_I2C_STATUS_MAST_WR_NO_ACK:
208 case MV64XXX_I2C_STATUS_MAST_RD_ADDR_NO_ACK:
209
210 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
211 drv_data->state = MV64XXX_I2C_STATE_IDLE;
212 drv_data->rc = -ENODEV;
213 break;
214
215 default:
216 dev_err(&drv_data->adapter.dev,
217 "mv64xxx_i2c_fsm: Ctlr Error -- state: 0x%x, "
218 "status: 0x%x, addr: 0x%x, flags: 0x%x\n",
219 drv_data->state, status, drv_data->msg->addr,
220 drv_data->msg->flags);
221 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
222 mv64xxx_i2c_hw_init(drv_data);
223 drv_data->rc = -EIO;
224 }
225}
226
227static void
228mv64xxx_i2c_do_action(struct mv64xxx_i2c_data *drv_data)
229{
230 switch(drv_data->action) {
231 case MV64XXX_I2C_ACTION_CONTINUE:
232 writel(drv_data->cntl_bits,
233 drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
234 break;
235
236 case MV64XXX_I2C_ACTION_SEND_START:
237 writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_START,
238 drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
239 break;
240
241 case MV64XXX_I2C_ACTION_SEND_ADDR_1:
242 writel(drv_data->addr1,
243 drv_data->reg_base + MV64XXX_I2C_REG_DATA);
244 writel(drv_data->cntl_bits,
245 drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
246 break;
247
248 case MV64XXX_I2C_ACTION_SEND_ADDR_2:
249 writel(drv_data->addr2,
250 drv_data->reg_base + MV64XXX_I2C_REG_DATA);
251 writel(drv_data->cntl_bits,
252 drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
253 break;
254
255 case MV64XXX_I2C_ACTION_SEND_DATA:
256 writel(drv_data->msg->buf[drv_data->byte_posn++],
257 drv_data->reg_base + MV64XXX_I2C_REG_DATA);
258 writel(drv_data->cntl_bits,
259 drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
260 break;
261
262 case MV64XXX_I2C_ACTION_RCV_DATA:
263 drv_data->msg->buf[drv_data->byte_posn++] =
264 readl(drv_data->reg_base + MV64XXX_I2C_REG_DATA);
265 writel(drv_data->cntl_bits,
266 drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
267 break;
268
269 case MV64XXX_I2C_ACTION_RCV_DATA_STOP:
270 drv_data->msg->buf[drv_data->byte_posn++] =
271 readl(drv_data->reg_base + MV64XXX_I2C_REG_DATA);
272 drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_INTEN;
273 writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_STOP,
274 drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
275 drv_data->block = 0;
276 wake_up_interruptible(&drv_data->waitq);
277 break;
278
279 case MV64XXX_I2C_ACTION_INVALID:
280 default:
281 dev_err(&drv_data->adapter.dev,
282 "mv64xxx_i2c_do_action: Invalid action: %d\n",
283 drv_data->action);
284 drv_data->rc = -EIO;
285
286 case MV64XXX_I2C_ACTION_SEND_STOP:
287 drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_INTEN;
288 writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_STOP,
289 drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
290 drv_data->block = 0;
291 wake_up_interruptible(&drv_data->waitq);
292 break;
293 }
294}
295
296static irqreturn_t
297mv64xxx_i2c_intr(int irq, void *dev_id)
298{
299 struct mv64xxx_i2c_data *drv_data = dev_id;
300 unsigned long flags;
301 u32 status;
302 irqreturn_t rc = IRQ_NONE;
303
304 spin_lock_irqsave(&drv_data->lock, flags);
305 while (readl(drv_data->reg_base + MV64XXX_I2C_REG_CONTROL) &
306 MV64XXX_I2C_REG_CONTROL_IFLG) {
307 status = readl(drv_data->reg_base + MV64XXX_I2C_REG_STATUS);
308 mv64xxx_i2c_fsm(drv_data, status);
309 mv64xxx_i2c_do_action(drv_data);
310 rc = IRQ_HANDLED;
311 }
312 spin_unlock_irqrestore(&drv_data->lock, flags);
313
314 return rc;
315}
316
317
318
319
320
321
322
323
324static void
325mv64xxx_i2c_prepare_for_io(struct mv64xxx_i2c_data *drv_data,
326 struct i2c_msg *msg)
327{
328 u32 dir = 0;
329
330 drv_data->msg = msg;
331 drv_data->byte_posn = 0;
332 drv_data->bytes_left = msg->len;
333 drv_data->aborting = 0;
334 drv_data->rc = 0;
335 drv_data->cntl_bits = MV64XXX_I2C_REG_CONTROL_ACK |
336 MV64XXX_I2C_REG_CONTROL_INTEN | MV64XXX_I2C_REG_CONTROL_TWSIEN;
337
338 if (msg->flags & I2C_M_RD)
339 dir = 1;
340
341 if (msg->flags & I2C_M_REV_DIR_ADDR)
342 dir ^= 1;
343
344 if (msg->flags & I2C_M_TEN) {
345 drv_data->addr1 = 0xf0 | (((u32)msg->addr & 0x300) >> 7) | dir;
346 drv_data->addr2 = (u32)msg->addr & 0xff;
347 } else {
348 drv_data->addr1 = ((u32)msg->addr & 0x7f) << 1 | dir;
349 drv_data->addr2 = 0;
350 }
351}
352
353static void
354mv64xxx_i2c_wait_for_completion(struct mv64xxx_i2c_data *drv_data)
355{
356 long time_left;
357 unsigned long flags;
358 char abort = 0;
359
360 time_left = wait_event_interruptible_timeout(drv_data->waitq,
361 !drv_data->block, drv_data->adapter.timeout);
362
363 spin_lock_irqsave(&drv_data->lock, flags);
364 if (!time_left) {
365 drv_data->rc = -ETIMEDOUT;
366 abort = 1;
367 } else if (time_left < 0) {
368 drv_data->rc = time_left;
369 abort = 1;
370 }
371
372 if (abort && drv_data->block) {
373 drv_data->aborting = 1;
374 spin_unlock_irqrestore(&drv_data->lock, flags);
375
376 time_left = wait_event_timeout(drv_data->waitq,
377 !drv_data->block, drv_data->adapter.timeout);
378
379 if ((time_left <= 0) && drv_data->block) {
380 drv_data->state = MV64XXX_I2C_STATE_IDLE;
381 dev_err(&drv_data->adapter.dev,
382 "mv64xxx: I2C bus locked, block: %d, "
383 "time_left: %d\n", drv_data->block,
384 (int)time_left);
385 mv64xxx_i2c_hw_init(drv_data);
386 }
387 } else
388 spin_unlock_irqrestore(&drv_data->lock, flags);
389}
390
391static int
392mv64xxx_i2c_execute_msg(struct mv64xxx_i2c_data *drv_data, struct i2c_msg *msg)
393{
394 unsigned long flags;
395
396 spin_lock_irqsave(&drv_data->lock, flags);
397 mv64xxx_i2c_prepare_for_io(drv_data, msg);
398
399 if (unlikely(msg->flags & I2C_M_NOSTART)) {
400 if (drv_data->msg->flags & I2C_M_RD) {
401
402 drv_data->action = MV64XXX_I2C_ACTION_CONTINUE;
403 drv_data->state =
404 MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_DATA;
405 } else {
406 drv_data->action = MV64XXX_I2C_ACTION_SEND_DATA;
407 drv_data->state =
408 MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_ACK;
409 drv_data->bytes_left--;
410 }
411 } else {
412 drv_data->action = MV64XXX_I2C_ACTION_SEND_START;
413 drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_START_COND;
414 }
415
416 drv_data->block = 1;
417 mv64xxx_i2c_do_action(drv_data);
418 spin_unlock_irqrestore(&drv_data->lock, flags);
419
420 mv64xxx_i2c_wait_for_completion(drv_data);
421 return drv_data->rc;
422}
423
424
425
426
427
428
429
430
431static u32
432mv64xxx_i2c_functionality(struct i2c_adapter *adap)
433{
434 return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | I2C_FUNC_SMBUS_EMUL;
435}
436
437static int
438mv64xxx_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
439{
440 struct mv64xxx_i2c_data *drv_data = i2c_get_adapdata(adap);
441 int i, rc;
442
443 for (i=0; i<num; i++)
444 if ((rc = mv64xxx_i2c_execute_msg(drv_data, &msgs[i])) < 0)
445 return rc;
446
447 return num;
448}
449
450static const struct i2c_algorithm mv64xxx_i2c_algo = {
451 .master_xfer = mv64xxx_i2c_xfer,
452 .functionality = mv64xxx_i2c_functionality,
453};
454
455
456
457
458
459
460
461
462static int __devinit
463mv64xxx_i2c_map_regs(struct platform_device *pd,
464 struct mv64xxx_i2c_data *drv_data)
465{
466 int size;
467 struct resource *r = platform_get_resource(pd, IORESOURCE_MEM, 0);
468
469 if (!r)
470 return -ENODEV;
471
472 size = resource_size(r);
473
474 if (!request_mem_region(r->start, size, drv_data->adapter.name))
475 return -EBUSY;
476
477 drv_data->reg_base = ioremap(r->start, size);
478 drv_data->reg_base_p = r->start;
479 drv_data->reg_size = size;
480
481 return 0;
482}
483
484static void
485mv64xxx_i2c_unmap_regs(struct mv64xxx_i2c_data *drv_data)
486{
487 if (drv_data->reg_base) {
488 iounmap(drv_data->reg_base);
489 release_mem_region(drv_data->reg_base_p, drv_data->reg_size);
490 }
491
492 drv_data->reg_base = NULL;
493 drv_data->reg_base_p = 0;
494}
495
496static int __devinit
497mv64xxx_i2c_probe(struct platform_device *pd)
498{
499 struct mv64xxx_i2c_data *drv_data;
500 struct mv64xxx_i2c_pdata *pdata = pd->dev.platform_data;
501 int rc;
502
503 if ((pd->id != 0) || !pdata)
504 return -ENODEV;
505
506 drv_data = kzalloc(sizeof(struct mv64xxx_i2c_data), GFP_KERNEL);
507 if (!drv_data)
508 return -ENOMEM;
509
510 if (mv64xxx_i2c_map_regs(pd, drv_data)) {
511 rc = -ENODEV;
512 goto exit_kfree;
513 }
514
515 strlcpy(drv_data->adapter.name, MV64XXX_I2C_CTLR_NAME " adapter",
516 sizeof(drv_data->adapter.name));
517
518 init_waitqueue_head(&drv_data->waitq);
519 spin_lock_init(&drv_data->lock);
520
521 drv_data->freq_m = pdata->freq_m;
522 drv_data->freq_n = pdata->freq_n;
523 drv_data->irq = platform_get_irq(pd, 0);
524 if (drv_data->irq < 0) {
525 rc = -ENXIO;
526 goto exit_unmap_regs;
527 }
528 drv_data->adapter.dev.parent = &pd->dev;
529 drv_data->adapter.algo = &mv64xxx_i2c_algo;
530 drv_data->adapter.owner = THIS_MODULE;
531 drv_data->adapter.class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
532 drv_data->adapter.timeout = msecs_to_jiffies(pdata->timeout);
533 drv_data->adapter.nr = pd->id;
534 platform_set_drvdata(pd, drv_data);
535 i2c_set_adapdata(&drv_data->adapter, drv_data);
536
537 mv64xxx_i2c_hw_init(drv_data);
538
539 if (request_irq(drv_data->irq, mv64xxx_i2c_intr, 0,
540 MV64XXX_I2C_CTLR_NAME, drv_data)) {
541 dev_err(&drv_data->adapter.dev,
542 "mv64xxx: Can't register intr handler irq: %d\n",
543 drv_data->irq);
544 rc = -EINVAL;
545 goto exit_unmap_regs;
546 } else if ((rc = i2c_add_numbered_adapter(&drv_data->adapter)) != 0) {
547 dev_err(&drv_data->adapter.dev,
548 "mv64xxx: Can't add i2c adapter, rc: %d\n", -rc);
549 goto exit_free_irq;
550 }
551
552 return 0;
553
554 exit_free_irq:
555 free_irq(drv_data->irq, drv_data);
556 exit_unmap_regs:
557 mv64xxx_i2c_unmap_regs(drv_data);
558 exit_kfree:
559 kfree(drv_data);
560 return rc;
561}
562
563static int __devexit
564mv64xxx_i2c_remove(struct platform_device *dev)
565{
566 struct mv64xxx_i2c_data *drv_data = platform_get_drvdata(dev);
567 int rc;
568
569 rc = i2c_del_adapter(&drv_data->adapter);
570 free_irq(drv_data->irq, drv_data);
571 mv64xxx_i2c_unmap_regs(drv_data);
572 kfree(drv_data);
573
574 return rc;
575}
576
577static struct platform_driver mv64xxx_i2c_driver = {
578 .probe = mv64xxx_i2c_probe,
579 .remove = __devexit_p(mv64xxx_i2c_remove),
580 .driver = {
581 .owner = THIS_MODULE,
582 .name = MV64XXX_I2C_CTLR_NAME,
583 },
584};
585
586static int __init
587mv64xxx_i2c_init(void)
588{
589 return platform_driver_register(&mv64xxx_i2c_driver);
590}
591
592static void __exit
593mv64xxx_i2c_exit(void)
594{
595 platform_driver_unregister(&mv64xxx_i2c_driver);
596}
597
598module_init(mv64xxx_i2c_init);
599module_exit(mv64xxx_i2c_exit);
600
601MODULE_AUTHOR("Mark A. Greer <mgreer@mvista.com>");
602MODULE_DESCRIPTION("Marvell mv64xxx host bridge i2c ctlr driver");
603MODULE_LICENSE("GPL");
604