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22#include <linux/kernel.h>
23#include <linux/module.h>
24#include <linux/moduleparam.h>
25#include <linux/delay.h>
26#include <linux/jiffies.h>
27#include <linux/errno.h>
28#include <linux/i2c.h>
29#include <linux/i2c-algo-pca.h>
30
31#define DEB1(fmt, args...) do { if (i2c_debug >= 1) \
32 printk(KERN_DEBUG fmt, ## args); } while (0)
33#define DEB2(fmt, args...) do { if (i2c_debug >= 2) \
34 printk(KERN_DEBUG fmt, ## args); } while (0)
35#define DEB3(fmt, args...) do { if (i2c_debug >= 3) \
36 printk(KERN_DEBUG fmt, ## args); } while (0)
37
38static int i2c_debug;
39
40#define pca_outw(adap, reg, val) adap->write_byte(adap->data, reg, val)
41#define pca_inw(adap, reg) adap->read_byte(adap->data, reg)
42
43#define pca_status(adap) pca_inw(adap, I2C_PCA_STA)
44#define pca_clock(adap) adap->i2c_clock
45#define pca_set_con(adap, val) pca_outw(adap, I2C_PCA_CON, val)
46#define pca_get_con(adap) pca_inw(adap, I2C_PCA_CON)
47#define pca_wait(adap) adap->wait_for_completion(adap->data)
48
49static void pca_reset(struct i2c_algo_pca_data *adap)
50{
51 if (adap->chip == I2C_PCA_CHIP_9665) {
52
53
54
55 pca_outw(adap, I2C_PCA_INDPTR, I2C_PCA_IPRESET);
56 pca_outw(adap, I2C_PCA_IND, 0xA5);
57 pca_outw(adap, I2C_PCA_IND, 0x5A);
58 } else {
59 adap->reset_chip(adap->data);
60 }
61}
62
63
64
65
66
67
68static int pca_start(struct i2c_algo_pca_data *adap)
69{
70 int sta = pca_get_con(adap);
71 DEB2("=== START\n");
72 sta |= I2C_PCA_CON_STA;
73 sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_SI);
74 pca_set_con(adap, sta);
75 return pca_wait(adap);
76}
77
78
79
80
81
82
83static int pca_repeated_start(struct i2c_algo_pca_data *adap)
84{
85 int sta = pca_get_con(adap);
86 DEB2("=== REPEATED START\n");
87 sta |= I2C_PCA_CON_STA;
88 sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_SI);
89 pca_set_con(adap, sta);
90 return pca_wait(adap);
91}
92
93
94
95
96
97
98
99
100
101
102static void pca_stop(struct i2c_algo_pca_data *adap)
103{
104 int sta = pca_get_con(adap);
105 DEB2("=== STOP\n");
106 sta |= I2C_PCA_CON_STO;
107 sta &= ~(I2C_PCA_CON_STA|I2C_PCA_CON_SI);
108 pca_set_con(adap, sta);
109}
110
111
112
113
114
115
116static int pca_address(struct i2c_algo_pca_data *adap,
117 struct i2c_msg *msg)
118{
119 int sta = pca_get_con(adap);
120 int addr;
121
122 addr = ((0x7f & msg->addr) << 1);
123 if (msg->flags & I2C_M_RD)
124 addr |= 1;
125 DEB2("=== SLAVE ADDRESS %#04x+%c=%#04x\n",
126 msg->addr, msg->flags & I2C_M_RD ? 'R' : 'W', addr);
127
128 pca_outw(adap, I2C_PCA_DAT, addr);
129
130 sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_STA|I2C_PCA_CON_SI);
131 pca_set_con(adap, sta);
132
133 return pca_wait(adap);
134}
135
136
137
138
139
140
141static int pca_tx_byte(struct i2c_algo_pca_data *adap,
142 __u8 b)
143{
144 int sta = pca_get_con(adap);
145 DEB2("=== WRITE %#04x\n", b);
146 pca_outw(adap, I2C_PCA_DAT, b);
147
148 sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_STA|I2C_PCA_CON_SI);
149 pca_set_con(adap, sta);
150
151 return pca_wait(adap);
152}
153
154
155
156
157
158
159static void pca_rx_byte(struct i2c_algo_pca_data *adap,
160 __u8 *b, int ack)
161{
162 *b = pca_inw(adap, I2C_PCA_DAT);
163 DEB2("=== READ %#04x %s\n", *b, ack ? "ACK" : "NACK");
164}
165
166
167
168
169
170
171static int pca_rx_ack(struct i2c_algo_pca_data *adap,
172 int ack)
173{
174 int sta = pca_get_con(adap);
175
176 sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_STA|I2C_PCA_CON_SI|I2C_PCA_CON_AA);
177
178 if (ack)
179 sta |= I2C_PCA_CON_AA;
180
181 pca_set_con(adap, sta);
182 return pca_wait(adap);
183}
184
185static int pca_xfer(struct i2c_adapter *i2c_adap,
186 struct i2c_msg *msgs,
187 int num)
188{
189 struct i2c_algo_pca_data *adap = i2c_adap->algo_data;
190 struct i2c_msg *msg = NULL;
191 int curmsg;
192 int numbytes = 0;
193 int state;
194 int ret;
195 int completed = 1;
196 unsigned long timeout = jiffies + i2c_adap->timeout;
197
198 while ((state = pca_status(adap)) != 0xf8) {
199 if (time_before(jiffies, timeout)) {
200 msleep(10);
201 } else {
202 dev_dbg(&i2c_adap->dev, "bus is not idle. status is "
203 "%#04x\n", state);
204 return -EBUSY;
205 }
206 }
207
208 DEB1("{{{ XFER %d messages\n", num);
209
210 if (i2c_debug >= 2) {
211 for (curmsg = 0; curmsg < num; curmsg++) {
212 int addr, i;
213 msg = &msgs[curmsg];
214
215 addr = (0x7f & msg->addr) ;
216
217 if (msg->flags & I2C_M_RD)
218 printk(KERN_INFO " [%02d] RD %d bytes from %#02x [%#02x, ...]\n",
219 curmsg, msg->len, addr, (addr << 1) | 1);
220 else {
221 printk(KERN_INFO " [%02d] WR %d bytes to %#02x [%#02x%s",
222 curmsg, msg->len, addr, addr << 1,
223 msg->len == 0 ? "" : ", ");
224 for (i = 0; i < msg->len; i++)
225 printk("%#04x%s", msg->buf[i], i == msg->len - 1 ? "" : ", ");
226 printk("]\n");
227 }
228 }
229 }
230
231 curmsg = 0;
232 ret = -EIO;
233 while (curmsg < num) {
234 state = pca_status(adap);
235
236 DEB3("STATE is 0x%02x\n", state);
237 msg = &msgs[curmsg];
238
239 switch (state) {
240 case 0xf8:
241 completed = pca_start(adap);
242 break;
243
244 case 0x08:
245 case 0x10:
246 completed = pca_address(adap, msg);
247 break;
248
249 case 0x18:
250 case 0x28:
251 if (numbytes < msg->len) {
252 completed = pca_tx_byte(adap,
253 msg->buf[numbytes]);
254 numbytes++;
255 break;
256 }
257 curmsg++; numbytes = 0;
258 if (curmsg == num)
259 pca_stop(adap);
260 else
261 completed = pca_repeated_start(adap);
262 break;
263
264 case 0x20:
265 DEB2("NOT ACK received after SLA+W\n");
266 pca_stop(adap);
267 ret = -ENXIO;
268 goto out;
269
270 case 0x40:
271 completed = pca_rx_ack(adap, msg->len > 1);
272 break;
273
274 case 0x50:
275 if (numbytes < msg->len) {
276 pca_rx_byte(adap, &msg->buf[numbytes], 1);
277 numbytes++;
278 completed = pca_rx_ack(adap,
279 numbytes < msg->len - 1);
280 break;
281 }
282 curmsg++; numbytes = 0;
283 if (curmsg == num)
284 pca_stop(adap);
285 else
286 completed = pca_repeated_start(adap);
287 break;
288
289 case 0x48:
290 DEB2("NOT ACK received after SLA+R\n");
291 pca_stop(adap);
292 ret = -ENXIO;
293 goto out;
294
295 case 0x30:
296 DEB2("NOT ACK received after data byte\n");
297 pca_stop(adap);
298 goto out;
299
300 case 0x38:
301 DEB2("Arbitration lost\n");
302
303
304
305
306
307
308
309
310
311 pca_start(adap);
312 goto out;
313
314 case 0x58:
315 if (numbytes == msg->len - 1) {
316 pca_rx_byte(adap, &msg->buf[numbytes], 0);
317 curmsg++; numbytes = 0;
318 if (curmsg == num)
319 pca_stop(adap);
320 else
321 completed = pca_repeated_start(adap);
322 } else {
323 DEB2("NOT ACK sent after data byte received. "
324 "Not final byte. numbytes %d. len %d\n",
325 numbytes, msg->len);
326 pca_stop(adap);
327 goto out;
328 }
329 break;
330 case 0x70:
331 DEB2("BUS ERROR - SDA Stuck low\n");
332 pca_reset(adap);
333 goto out;
334 case 0x90:
335 DEB2("BUS ERROR - SCL Stuck low\n");
336 pca_reset(adap);
337 goto out;
338 case 0x00:
339 DEB2("BUS ERROR - Illegal START or STOP\n");
340 pca_reset(adap);
341 goto out;
342 default:
343 dev_err(&i2c_adap->dev, "unhandled SIO state 0x%02x\n", state);
344 break;
345 }
346
347 if (!completed)
348 goto out;
349 }
350
351 ret = curmsg;
352 out:
353 DEB1("}}} transferred %d/%d messages. "
354 "status is %#04x. control is %#04x\n",
355 curmsg, num, pca_status(adap),
356 pca_get_con(adap));
357 return ret;
358}
359
360static u32 pca_func(struct i2c_adapter *adap)
361{
362 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
363}
364
365static const struct i2c_algorithm pca_algo = {
366 .master_xfer = pca_xfer,
367 .functionality = pca_func,
368};
369
370static unsigned int pca_probe_chip(struct i2c_adapter *adap)
371{
372 struct i2c_algo_pca_data *pca_data = adap->algo_data;
373
374
375
376
377
378 pca_outw(pca_data, I2C_PCA_INDPTR, I2C_PCA_IADR);
379 pca_outw(pca_data, I2C_PCA_IND, 0xAA);
380 pca_outw(pca_data, I2C_PCA_INDPTR, I2C_PCA_ITO);
381 pca_outw(pca_data, I2C_PCA_IND, 0x00);
382 pca_outw(pca_data, I2C_PCA_INDPTR, I2C_PCA_IADR);
383 if (pca_inw(pca_data, I2C_PCA_IND) == 0xAA) {
384 printk(KERN_INFO "%s: PCA9665 detected.\n", adap->name);
385 pca_data->chip = I2C_PCA_CHIP_9665;
386 } else {
387 printk(KERN_INFO "%s: PCA9564 detected.\n", adap->name);
388 pca_data->chip = I2C_PCA_CHIP_9564;
389 }
390 return pca_data->chip;
391}
392
393static int pca_init(struct i2c_adapter *adap)
394{
395 struct i2c_algo_pca_data *pca_data = adap->algo_data;
396
397 adap->algo = &pca_algo;
398
399 if (pca_probe_chip(adap) == I2C_PCA_CHIP_9564) {
400 static int freqs[] = {330, 288, 217, 146, 88, 59, 44, 36};
401 int clock;
402
403 if (pca_data->i2c_clock > 7) {
404 switch (pca_data->i2c_clock) {
405 case 330000:
406 pca_data->i2c_clock = I2C_PCA_CON_330kHz;
407 break;
408 case 288000:
409 pca_data->i2c_clock = I2C_PCA_CON_288kHz;
410 break;
411 case 217000:
412 pca_data->i2c_clock = I2C_PCA_CON_217kHz;
413 break;
414 case 146000:
415 pca_data->i2c_clock = I2C_PCA_CON_146kHz;
416 break;
417 case 88000:
418 pca_data->i2c_clock = I2C_PCA_CON_88kHz;
419 break;
420 case 59000:
421 pca_data->i2c_clock = I2C_PCA_CON_59kHz;
422 break;
423 case 44000:
424 pca_data->i2c_clock = I2C_PCA_CON_44kHz;
425 break;
426 case 36000:
427 pca_data->i2c_clock = I2C_PCA_CON_36kHz;
428 break;
429 default:
430 printk(KERN_WARNING
431 "%s: Invalid I2C clock speed selected."
432 " Using default 59kHz.\n", adap->name);
433 pca_data->i2c_clock = I2C_PCA_CON_59kHz;
434 }
435 } else {
436 printk(KERN_WARNING "%s: "
437 "Choosing the clock frequency based on "
438 "index is deprecated."
439 " Use the nominal frequency.\n", adap->name);
440 }
441
442 pca_reset(pca_data);
443
444 clock = pca_clock(pca_data);
445 printk(KERN_INFO "%s: Clock frequency is %dkHz\n",
446 adap->name, freqs[clock]);
447
448 pca_set_con(pca_data, I2C_PCA_CON_ENSIO | clock);
449 } else {
450 int clock;
451 int mode;
452 int tlow, thi;
453
454 int min_tlow, min_thi;
455
456
457
458
459
460
461
462 int raise_fall_time;
463
464 if (pca_data->i2c_clock > 1265800) {
465 printk(KERN_WARNING "%s: I2C clock speed too high."
466 " Using 1265.8kHz.\n", adap->name);
467 pca_data->i2c_clock = 1265800;
468 }
469
470 if (pca_data->i2c_clock < 60300) {
471 printk(KERN_WARNING "%s: I2C clock speed too low."
472 " Using 60.3kHz.\n", adap->name);
473 pca_data->i2c_clock = 60300;
474 }
475
476
477 clock = pca_clock(pca_data) / 100;
478
479 if (pca_data->i2c_clock > 1000000) {
480 mode = I2C_PCA_MODE_TURBO;
481 min_tlow = 14;
482 min_thi = 5;
483 raise_fall_time = 22;
484 } else if (pca_data->i2c_clock > 400000) {
485 mode = I2C_PCA_MODE_FASTP;
486 min_tlow = 17;
487 min_thi = 9;
488 raise_fall_time = 22;
489 } else if (pca_data->i2c_clock > 100000) {
490 mode = I2C_PCA_MODE_FAST;
491 min_tlow = 44;
492 min_thi = 20;
493 raise_fall_time = 58;
494 } else {
495 mode = I2C_PCA_MODE_STD;
496 min_tlow = 157;
497 min_thi = 134;
498 raise_fall_time = 127;
499 }
500
501
502
503
504
505 if (clock < 648) {
506 tlow = 255;
507 thi = 1000000 - clock * raise_fall_time;
508 thi /= (I2C_PCA_OSC_PER * clock) - tlow;
509 } else {
510 tlow = (1000000 - clock * raise_fall_time) * min_tlow;
511 tlow /= I2C_PCA_OSC_PER * clock * (min_thi + min_tlow);
512 thi = tlow * min_thi / min_tlow;
513 }
514
515 pca_reset(pca_data);
516
517 printk(KERN_INFO
518 "%s: Clock frequency is %dHz\n", adap->name, clock * 100);
519
520 pca_outw(pca_data, I2C_PCA_INDPTR, I2C_PCA_IMODE);
521 pca_outw(pca_data, I2C_PCA_IND, mode);
522 pca_outw(pca_data, I2C_PCA_INDPTR, I2C_PCA_ISCLL);
523 pca_outw(pca_data, I2C_PCA_IND, tlow);
524 pca_outw(pca_data, I2C_PCA_INDPTR, I2C_PCA_ISCLH);
525 pca_outw(pca_data, I2C_PCA_IND, thi);
526
527 pca_set_con(pca_data, I2C_PCA_CON_ENSIO);
528 }
529 udelay(500);
530
531 return 0;
532}
533
534
535
536
537int i2c_pca_add_bus(struct i2c_adapter *adap)
538{
539 int rval;
540
541 rval = pca_init(adap);
542 if (rval)
543 return rval;
544
545 return i2c_add_adapter(adap);
546}
547EXPORT_SYMBOL(i2c_pca_add_bus);
548
549int i2c_pca_add_numbered_bus(struct i2c_adapter *adap)
550{
551 int rval;
552
553 rval = pca_init(adap);
554 if (rval)
555 return rval;
556
557 return i2c_add_numbered_adapter(adap);
558}
559EXPORT_SYMBOL(i2c_pca_add_numbered_bus);
560
561MODULE_AUTHOR("Ian Campbell <icampbell@arcom.com>, "
562 "Wolfram Sang <w.sang@pengutronix.de>");
563MODULE_DESCRIPTION("I2C-Bus PCA9564/PCA9665 algorithm");
564MODULE_LICENSE("GPL");
565
566module_param(i2c_debug, int, 0);
567