ALSA: ice1712: Fix build errors
[linux/fpc-iii.git] / drivers / i2c / algos / i2c-algo-pca.c
blobf892a424009b8123c3cb0ceb3dae75359cceaef9
1 /*
2 * i2c-algo-pca.c i2c driver algorithms for PCA9564 adapters
3 * Copyright (C) 2004 Arcom Control Systems
4 * Copyright (C) 2008 Pengutronix
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
19 * MA 02110-1301 USA.
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/init.h>
28 #include <linux/errno.h>
29 #include <linux/i2c.h>
30 #include <linux/i2c-algo-pca.h>
32 #define DEB1(fmt, args...) do { if (i2c_debug >= 1) \
33 printk(KERN_DEBUG fmt, ## args); } while (0)
34 #define DEB2(fmt, args...) do { if (i2c_debug >= 2) \
35 printk(KERN_DEBUG fmt, ## args); } while (0)
36 #define DEB3(fmt, args...) do { if (i2c_debug >= 3) \
37 printk(KERN_DEBUG fmt, ## args); } while (0)
39 static int i2c_debug;
41 #define pca_outw(adap, reg, val) adap->write_byte(adap->data, reg, val)
42 #define pca_inw(adap, reg) adap->read_byte(adap->data, reg)
44 #define pca_status(adap) pca_inw(adap, I2C_PCA_STA)
45 #define pca_clock(adap) adap->i2c_clock
46 #define pca_set_con(adap, val) pca_outw(adap, I2C_PCA_CON, val)
47 #define pca_get_con(adap) pca_inw(adap, I2C_PCA_CON)
48 #define pca_wait(adap) adap->wait_for_completion(adap->data)
50 static void pca_reset(struct i2c_algo_pca_data *adap)
52 if (adap->chip == I2C_PCA_CHIP_9665) {
53 /* Ignore the reset function from the module,
54 * we can use the parallel bus reset.
56 pca_outw(adap, I2C_PCA_INDPTR, I2C_PCA_IPRESET);
57 pca_outw(adap, I2C_PCA_IND, 0xA5);
58 pca_outw(adap, I2C_PCA_IND, 0x5A);
59 } else {
60 adap->reset_chip(adap->data);
65 * Generate a start condition on the i2c bus.
67 * returns after the start condition has occurred
69 static int pca_start(struct i2c_algo_pca_data *adap)
71 int sta = pca_get_con(adap);
72 DEB2("=== START\n");
73 sta |= I2C_PCA_CON_STA;
74 sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_SI);
75 pca_set_con(adap, sta);
76 return pca_wait(adap);
80 * Generate a repeated start condition on the i2c bus
82 * return after the repeated start condition has occurred
84 static int pca_repeated_start(struct i2c_algo_pca_data *adap)
86 int sta = pca_get_con(adap);
87 DEB2("=== REPEATED START\n");
88 sta |= I2C_PCA_CON_STA;
89 sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_SI);
90 pca_set_con(adap, sta);
91 return pca_wait(adap);
95 * Generate a stop condition on the i2c bus
97 * returns after the stop condition has been generated
99 * STOPs do not generate an interrupt or set the SI flag, since the
100 * part returns the idle state (0xf8). Hence we don't need to
101 * pca_wait here.
103 static void pca_stop(struct i2c_algo_pca_data *adap)
105 int sta = pca_get_con(adap);
106 DEB2("=== STOP\n");
107 sta |= I2C_PCA_CON_STO;
108 sta &= ~(I2C_PCA_CON_STA|I2C_PCA_CON_SI);
109 pca_set_con(adap, sta);
113 * Send the slave address and R/W bit
115 * returns after the address has been sent
117 static int pca_address(struct i2c_algo_pca_data *adap,
118 struct i2c_msg *msg)
120 int sta = pca_get_con(adap);
121 int addr;
123 addr = ((0x7f & msg->addr) << 1);
124 if (msg->flags & I2C_M_RD)
125 addr |= 1;
126 DEB2("=== SLAVE ADDRESS %#04x+%c=%#04x\n",
127 msg->addr, msg->flags & I2C_M_RD ? 'R' : 'W', addr);
129 pca_outw(adap, I2C_PCA_DAT, addr);
131 sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_STA|I2C_PCA_CON_SI);
132 pca_set_con(adap, sta);
134 return pca_wait(adap);
138 * Transmit a byte.
140 * Returns after the byte has been transmitted
142 static int pca_tx_byte(struct i2c_algo_pca_data *adap,
143 __u8 b)
145 int sta = pca_get_con(adap);
146 DEB2("=== WRITE %#04x\n", b);
147 pca_outw(adap, I2C_PCA_DAT, b);
149 sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_STA|I2C_PCA_CON_SI);
150 pca_set_con(adap, sta);
152 return pca_wait(adap);
156 * Receive a byte
158 * returns immediately.
160 static void pca_rx_byte(struct i2c_algo_pca_data *adap,
161 __u8 *b, int ack)
163 *b = pca_inw(adap, I2C_PCA_DAT);
164 DEB2("=== READ %#04x %s\n", *b, ack ? "ACK" : "NACK");
168 * Setup ACK or NACK for next received byte and wait for it to arrive.
170 * Returns after next byte has arrived.
172 static int pca_rx_ack(struct i2c_algo_pca_data *adap,
173 int ack)
175 int sta = pca_get_con(adap);
177 sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_STA|I2C_PCA_CON_SI|I2C_PCA_CON_AA);
179 if (ack)
180 sta |= I2C_PCA_CON_AA;
182 pca_set_con(adap, sta);
183 return pca_wait(adap);
186 static int pca_xfer(struct i2c_adapter *i2c_adap,
187 struct i2c_msg *msgs,
188 int num)
190 struct i2c_algo_pca_data *adap = i2c_adap->algo_data;
191 struct i2c_msg *msg = NULL;
192 int curmsg;
193 int numbytes = 0;
194 int state;
195 int ret;
196 int completed = 1;
197 unsigned long timeout = jiffies + i2c_adap->timeout;
199 while ((state = pca_status(adap)) != 0xf8) {
200 if (time_before(jiffies, timeout)) {
201 msleep(10);
202 } else {
203 dev_dbg(&i2c_adap->dev, "bus is not idle. status is "
204 "%#04x\n", state);
205 return -EBUSY;
209 DEB1("{{{ XFER %d messages\n", num);
211 if (i2c_debug >= 2) {
212 for (curmsg = 0; curmsg < num; curmsg++) {
213 int addr, i;
214 msg = &msgs[curmsg];
216 addr = (0x7f & msg->addr) ;
218 if (msg->flags & I2C_M_RD)
219 printk(KERN_INFO " [%02d] RD %d bytes from %#02x [%#02x, ...]\n",
220 curmsg, msg->len, addr, (addr << 1) | 1);
221 else {
222 printk(KERN_INFO " [%02d] WR %d bytes to %#02x [%#02x%s",
223 curmsg, msg->len, addr, addr << 1,
224 msg->len == 0 ? "" : ", ");
225 for (i = 0; i < msg->len; i++)
226 printk("%#04x%s", msg->buf[i], i == msg->len - 1 ? "" : ", ");
227 printk("]\n");
232 curmsg = 0;
233 ret = -EIO;
234 while (curmsg < num) {
235 state = pca_status(adap);
237 DEB3("STATE is 0x%02x\n", state);
238 msg = &msgs[curmsg];
240 switch (state) {
241 case 0xf8: /* On reset or stop the bus is idle */
242 completed = pca_start(adap);
243 break;
245 case 0x08: /* A START condition has been transmitted */
246 case 0x10: /* A repeated start condition has been transmitted */
247 completed = pca_address(adap, msg);
248 break;
250 case 0x18: /* SLA+W has been transmitted; ACK has been received */
251 case 0x28: /* Data byte in I2CDAT has been transmitted; ACK has been received */
252 if (numbytes < msg->len) {
253 completed = pca_tx_byte(adap,
254 msg->buf[numbytes]);
255 numbytes++;
256 break;
258 curmsg++; numbytes = 0;
259 if (curmsg == num)
260 pca_stop(adap);
261 else
262 completed = pca_repeated_start(adap);
263 break;
265 case 0x20: /* SLA+W has been transmitted; NOT ACK has been received */
266 DEB2("NOT ACK received after SLA+W\n");
267 pca_stop(adap);
268 ret = -ENXIO;
269 goto out;
271 case 0x40: /* SLA+R has been transmitted; ACK has been received */
272 completed = pca_rx_ack(adap, msg->len > 1);
273 break;
275 case 0x50: /* Data bytes has been received; ACK has been returned */
276 if (numbytes < msg->len) {
277 pca_rx_byte(adap, &msg->buf[numbytes], 1);
278 numbytes++;
279 completed = pca_rx_ack(adap,
280 numbytes < msg->len - 1);
281 break;
283 curmsg++; numbytes = 0;
284 if (curmsg == num)
285 pca_stop(adap);
286 else
287 completed = pca_repeated_start(adap);
288 break;
290 case 0x48: /* SLA+R has been transmitted; NOT ACK has been received */
291 DEB2("NOT ACK received after SLA+R\n");
292 pca_stop(adap);
293 ret = -ENXIO;
294 goto out;
296 case 0x30: /* Data byte in I2CDAT has been transmitted; NOT ACK has been received */
297 DEB2("NOT ACK received after data byte\n");
298 pca_stop(adap);
299 goto out;
301 case 0x38: /* Arbitration lost during SLA+W, SLA+R or data bytes */
302 DEB2("Arbitration lost\n");
304 * The PCA9564 data sheet (2006-09-01) says "A
305 * START condition will be transmitted when the
306 * bus becomes free (STOP or SCL and SDA high)"
307 * when the STA bit is set (p. 11).
309 * In case this won't work, try pca_reset()
310 * instead.
312 pca_start(adap);
313 goto out;
315 case 0x58: /* Data byte has been received; NOT ACK has been returned */
316 if (numbytes == msg->len - 1) {
317 pca_rx_byte(adap, &msg->buf[numbytes], 0);
318 curmsg++; numbytes = 0;
319 if (curmsg == num)
320 pca_stop(adap);
321 else
322 completed = pca_repeated_start(adap);
323 } else {
324 DEB2("NOT ACK sent after data byte received. "
325 "Not final byte. numbytes %d. len %d\n",
326 numbytes, msg->len);
327 pca_stop(adap);
328 goto out;
330 break;
331 case 0x70: /* Bus error - SDA stuck low */
332 DEB2("BUS ERROR - SDA Stuck low\n");
333 pca_reset(adap);
334 goto out;
335 case 0x90: /* Bus error - SCL stuck low */
336 DEB2("BUS ERROR - SCL Stuck low\n");
337 pca_reset(adap);
338 goto out;
339 case 0x00: /* Bus error during master or slave mode due to illegal START or STOP condition */
340 DEB2("BUS ERROR - Illegal START or STOP\n");
341 pca_reset(adap);
342 goto out;
343 default:
344 dev_err(&i2c_adap->dev, "unhandled SIO state 0x%02x\n", state);
345 break;
348 if (!completed)
349 goto out;
352 ret = curmsg;
353 out:
354 DEB1("}}} transferred %d/%d messages. "
355 "status is %#04x. control is %#04x\n",
356 curmsg, num, pca_status(adap),
357 pca_get_con(adap));
358 return ret;
361 static u32 pca_func(struct i2c_adapter *adap)
363 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
366 static const struct i2c_algorithm pca_algo = {
367 .master_xfer = pca_xfer,
368 .functionality = pca_func,
371 static unsigned int pca_probe_chip(struct i2c_adapter *adap)
373 struct i2c_algo_pca_data *pca_data = adap->algo_data;
374 /* The trick here is to check if there is an indirect register
375 * available. If there is one, we will read the value we first
376 * wrote on I2C_PCA_IADR. Otherwise, we will read the last value
377 * we wrote on I2C_PCA_ADR
379 pca_outw(pca_data, I2C_PCA_INDPTR, I2C_PCA_IADR);
380 pca_outw(pca_data, I2C_PCA_IND, 0xAA);
381 pca_outw(pca_data, I2C_PCA_INDPTR, I2C_PCA_ITO);
382 pca_outw(pca_data, I2C_PCA_IND, 0x00);
383 pca_outw(pca_data, I2C_PCA_INDPTR, I2C_PCA_IADR);
384 if (pca_inw(pca_data, I2C_PCA_IND) == 0xAA) {
385 printk(KERN_INFO "%s: PCA9665 detected.\n", adap->name);
386 pca_data->chip = I2C_PCA_CHIP_9665;
387 } else {
388 printk(KERN_INFO "%s: PCA9564 detected.\n", adap->name);
389 pca_data->chip = I2C_PCA_CHIP_9564;
391 return pca_data->chip;
394 static int pca_init(struct i2c_adapter *adap)
396 struct i2c_algo_pca_data *pca_data = adap->algo_data;
398 adap->algo = &pca_algo;
400 if (pca_probe_chip(adap) == I2C_PCA_CHIP_9564) {
401 static int freqs[] = {330, 288, 217, 146, 88, 59, 44, 36};
402 int clock;
404 if (pca_data->i2c_clock > 7) {
405 switch (pca_data->i2c_clock) {
406 case 330000:
407 pca_data->i2c_clock = I2C_PCA_CON_330kHz;
408 break;
409 case 288000:
410 pca_data->i2c_clock = I2C_PCA_CON_288kHz;
411 break;
412 case 217000:
413 pca_data->i2c_clock = I2C_PCA_CON_217kHz;
414 break;
415 case 146000:
416 pca_data->i2c_clock = I2C_PCA_CON_146kHz;
417 break;
418 case 88000:
419 pca_data->i2c_clock = I2C_PCA_CON_88kHz;
420 break;
421 case 59000:
422 pca_data->i2c_clock = I2C_PCA_CON_59kHz;
423 break;
424 case 44000:
425 pca_data->i2c_clock = I2C_PCA_CON_44kHz;
426 break;
427 case 36000:
428 pca_data->i2c_clock = I2C_PCA_CON_36kHz;
429 break;
430 default:
431 printk(KERN_WARNING
432 "%s: Invalid I2C clock speed selected."
433 " Using default 59kHz.\n", adap->name);
434 pca_data->i2c_clock = I2C_PCA_CON_59kHz;
436 } else {
437 printk(KERN_WARNING "%s: "
438 "Choosing the clock frequency based on "
439 "index is deprecated."
440 " Use the nominal frequency.\n", adap->name);
443 pca_reset(pca_data);
445 clock = pca_clock(pca_data);
446 printk(KERN_INFO "%s: Clock frequency is %dkHz\n",
447 adap->name, freqs[clock]);
449 pca_set_con(pca_data, I2C_PCA_CON_ENSIO | clock);
450 } else {
451 int clock;
452 int mode;
453 int tlow, thi;
454 /* Values can be found on PCA9665 datasheet section 7.3.2.6 */
455 int min_tlow, min_thi;
456 /* These values are the maximum raise and fall values allowed
457 * by the I2C operation mode (Standard, Fast or Fast+)
458 * They are used (added) below to calculate the clock dividers
459 * of PCA9665. Note that they are slightly different of the
460 * real maximum, to allow the change on mode exactly on the
461 * maximum clock rate for each mode
463 int raise_fall_time;
465 if (pca_data->i2c_clock > 1265800) {
466 printk(KERN_WARNING "%s: I2C clock speed too high."
467 " Using 1265.8kHz.\n", adap->name);
468 pca_data->i2c_clock = 1265800;
471 if (pca_data->i2c_clock < 60300) {
472 printk(KERN_WARNING "%s: I2C clock speed too low."
473 " Using 60.3kHz.\n", adap->name);
474 pca_data->i2c_clock = 60300;
477 /* To avoid integer overflow, use clock/100 for calculations */
478 clock = pca_clock(pca_data) / 100;
480 if (pca_data->i2c_clock > 1000000) {
481 mode = I2C_PCA_MODE_TURBO;
482 min_tlow = 14;
483 min_thi = 5;
484 raise_fall_time = 22; /* Raise 11e-8s, Fall 11e-8s */
485 } else if (pca_data->i2c_clock > 400000) {
486 mode = I2C_PCA_MODE_FASTP;
487 min_tlow = 17;
488 min_thi = 9;
489 raise_fall_time = 22; /* Raise 11e-8s, Fall 11e-8s */
490 } else if (pca_data->i2c_clock > 100000) {
491 mode = I2C_PCA_MODE_FAST;
492 min_tlow = 44;
493 min_thi = 20;
494 raise_fall_time = 58; /* Raise 29e-8s, Fall 29e-8s */
495 } else {
496 mode = I2C_PCA_MODE_STD;
497 min_tlow = 157;
498 min_thi = 134;
499 raise_fall_time = 127; /* Raise 29e-8s, Fall 98e-8s */
502 /* The minimum clock that respects the thi/tlow = 134/157 is
503 * 64800 Hz. Below that, we have to fix the tlow to 255 and
504 * calculate the thi factor.
506 if (clock < 648) {
507 tlow = 255;
508 thi = 1000000 - clock * raise_fall_time;
509 thi /= (I2C_PCA_OSC_PER * clock) - tlow;
510 } else {
511 tlow = (1000000 - clock * raise_fall_time) * min_tlow;
512 tlow /= I2C_PCA_OSC_PER * clock * (min_thi + min_tlow);
513 thi = tlow * min_thi / min_tlow;
516 pca_reset(pca_data);
518 printk(KERN_INFO
519 "%s: Clock frequency is %dHz\n", adap->name, clock * 100);
521 pca_outw(pca_data, I2C_PCA_INDPTR, I2C_PCA_IMODE);
522 pca_outw(pca_data, I2C_PCA_IND, mode);
523 pca_outw(pca_data, I2C_PCA_INDPTR, I2C_PCA_ISCLL);
524 pca_outw(pca_data, I2C_PCA_IND, tlow);
525 pca_outw(pca_data, I2C_PCA_INDPTR, I2C_PCA_ISCLH);
526 pca_outw(pca_data, I2C_PCA_IND, thi);
528 pca_set_con(pca_data, I2C_PCA_CON_ENSIO);
530 udelay(500); /* 500 us for oscilator to stabilise */
532 return 0;
536 * registering functions to load algorithms at runtime
538 int i2c_pca_add_bus(struct i2c_adapter *adap)
540 int rval;
542 rval = pca_init(adap);
543 if (rval)
544 return rval;
546 return i2c_add_adapter(adap);
548 EXPORT_SYMBOL(i2c_pca_add_bus);
550 int i2c_pca_add_numbered_bus(struct i2c_adapter *adap)
552 int rval;
554 rval = pca_init(adap);
555 if (rval)
556 return rval;
558 return i2c_add_numbered_adapter(adap);
560 EXPORT_SYMBOL(i2c_pca_add_numbered_bus);
562 MODULE_AUTHOR("Ian Campbell <icampbell@arcom.com>, "
563 "Wolfram Sang <w.sang@pengutronix.de>");
564 MODULE_DESCRIPTION("I2C-Bus PCA9564/PCA9665 algorithm");
565 MODULE_LICENSE("GPL");
567 module_param(i2c_debug, int, 0);