1// SPDX-License-Identifier: GPL-2.0+
2//
3// em28xx-i2c.c - driver for Empia EM2800/EM2820/2840 USB video capture devices
4//
5// Copyright (C) 2005 Ludovico Cavedon <cavedon@sssup.it>
6// Markus Rechberger <mrechberger@gmail.com>
7// Mauro Carvalho Chehab <mchehab@kernel.org>
8// Sascha Sommer <saschasommer@freenet.de>
9// Copyright (C) 2013 Frank Schäfer <fschaefer.oss@googlemail.com>
10
11#include "em28xx.h"
12
13#include <linux/module.h>
14#include <linux/kernel.h>
15#include <linux/usb.h>
16#include <linux/i2c.h>
17#include <linux/jiffies.h>
18
19#include "xc2028.h"
20#include <media/v4l2-common.h>
21#include <media/tuner.h>
22
23/* ----------------------------------------------------------- */
24
25static unsigned int i2c_scan;
26module_param(i2c_scan, int, 0444);
27MODULE_PARM_DESC(i2c_scan, "scan i2c bus at insmod time");
28
29static unsigned int i2c_debug;
30module_param(i2c_debug, int, 0644);
31MODULE_PARM_DESC(i2c_debug, "i2c debug message level (1: normal debug, 2: show I2C transfers)");
32
33#define dprintk(level, fmt, arg...) do { \
34 if (i2c_debug > level) \
35 dev_printk(KERN_DEBUG, &dev->intf->dev, \
36 "i2c: %s: " fmt, __func__, ## arg); \
37} while (0)
38
39/*
40 * Time in msecs to wait for i2c xfers to finish.
41 * 35ms is the maximum time a SMBUS device could wait when
42 * clock stretching is used. As the transfer itself will take
43 * some time to happen, set it to 35 ms.
44 *
45 * Ok, I2C doesn't specify any limit. So, eventually, we may need
46 * to increase this timeout.
47 */
48#define EM28XX_I2C_XFER_TIMEOUT 35 /* ms */
49
50static int em28xx_i2c_timeout(struct em28xx *dev)
51{
52 int time = EM28XX_I2C_XFER_TIMEOUT;
53
54 switch (dev->i2c_speed & 0x03) {
55 case EM28XX_I2C_FREQ_25_KHZ:
56 time += 4; /* Assume 4 ms for transfers */
57 break;
58 case EM28XX_I2C_FREQ_100_KHZ:
59 case EM28XX_I2C_FREQ_400_KHZ:
60 time += 1; /* Assume 1 ms for transfers */
61 break;
62 default: /* EM28XX_I2C_FREQ_1_5_MHZ */
63 break;
64 }
65
66 return msecs_to_jiffies(m: time);
67}
68
69/*
70 * em2800_i2c_send_bytes()
71 * send up to 4 bytes to the em2800 i2c device
72 */
73static int em2800_i2c_send_bytes(struct em28xx *dev, u8 addr, u8 *buf, u16 len)
74{
75 unsigned long timeout = jiffies + em28xx_i2c_timeout(dev);
76 int ret;
77 u8 b2[6];
78
79 if (len < 1 || len > 4)
80 return -EOPNOTSUPP;
81
82 b2[5] = 0x80 + len - 1;
83 b2[4] = addr;
84 b2[3] = buf[0];
85 if (len > 1)
86 b2[2] = buf[1];
87 if (len > 2)
88 b2[1] = buf[2];
89 if (len > 3)
90 b2[0] = buf[3];
91
92 /* trigger write */
93 ret = dev->em28xx_write_regs(dev, 4 - len, &b2[4 - len], 2 + len);
94 if (ret != 2 + len) {
95 dev_warn(&dev->intf->dev,
96 "failed to trigger write to i2c address 0x%x (error=%i)\n",
97 addr, ret);
98 return (ret < 0) ? ret : -EIO;
99 }
100 /* wait for completion */
101 while (time_is_after_jiffies(timeout)) {
102 ret = dev->em28xx_read_reg(dev, 0x05);
103 if (ret == 0x80 + len - 1)
104 return len;
105 if (ret == 0x94 + len - 1) {
106 dprintk(1, "R05 returned 0x%02x: I2C ACK error\n", ret);
107 return -ENXIO;
108 }
109 if (ret < 0) {
110 dev_warn(&dev->intf->dev,
111 "failed to get i2c transfer status from bridge register (error=%i)\n",
112 ret);
113 return ret;
114 }
115 usleep_range(min: 5000, max: 6000);
116 }
117 dprintk(0, "write to i2c device at 0x%x timed out\n", addr);
118 return -ETIMEDOUT;
119}
120
121/*
122 * em2800_i2c_recv_bytes()
123 * read up to 4 bytes from the em2800 i2c device
124 */
125static int em2800_i2c_recv_bytes(struct em28xx *dev, u8 addr, u8 *buf, u16 len)
126{
127 unsigned long timeout = jiffies + em28xx_i2c_timeout(dev);
128 u8 buf2[4];
129 int ret;
130 int i;
131
132 if (len < 1 || len > 4)
133 return -EOPNOTSUPP;
134
135 /* trigger read */
136 buf2[1] = 0x84 + len - 1;
137 buf2[0] = addr;
138 ret = dev->em28xx_write_regs(dev, 0x04, buf2, 2);
139 if (ret != 2) {
140 dev_warn(&dev->intf->dev,
141 "failed to trigger read from i2c address 0x%x (error=%i)\n",
142 addr, ret);
143 return (ret < 0) ? ret : -EIO;
144 }
145
146 /* wait for completion */
147 while (time_is_after_jiffies(timeout)) {
148 ret = dev->em28xx_read_reg(dev, 0x05);
149 if (ret == 0x84 + len - 1)
150 break;
151 if (ret == 0x94 + len - 1) {
152 dprintk(1, "R05 returned 0x%02x: I2C ACK error\n",
153 ret);
154 return -ENXIO;
155 }
156 if (ret < 0) {
157 dev_warn(&dev->intf->dev,
158 "failed to get i2c transfer status from bridge register (error=%i)\n",
159 ret);
160 return ret;
161 }
162 usleep_range(min: 5000, max: 6000);
163 }
164 if (ret != 0x84 + len - 1)
165 dprintk(0, "read from i2c device at 0x%x timed out\n", addr);
166
167 /* get the received message */
168 ret = dev->em28xx_read_reg_req_len(dev, 0x00, 4 - len, buf2, len);
169 if (ret != len) {
170 dev_warn(&dev->intf->dev,
171 "reading from i2c device at 0x%x failed: couldn't get the received message from the bridge (error=%i)\n",
172 addr, ret);
173 return (ret < 0) ? ret : -EIO;
174 }
175 for (i = 0; i < len; i++)
176 buf[i] = buf2[len - 1 - i];
177
178 return ret;
179}
180
181/*
182 * em2800_i2c_check_for_device()
183 * check if there is an i2c device at the supplied address
184 */
185static int em2800_i2c_check_for_device(struct em28xx *dev, u8 addr)
186{
187 u8 buf;
188 int ret;
189
190 ret = em2800_i2c_recv_bytes(dev, addr, buf: &buf, len: 1);
191 if (ret == 1)
192 return 0;
193 return (ret < 0) ? ret : -EIO;
194}
195
196/*
197 * em28xx_i2c_send_bytes()
198 */
199static int em28xx_i2c_send_bytes(struct em28xx *dev, u16 addr, u8 *buf,
200 u16 len, int stop)
201{
202 unsigned long timeout = jiffies + em28xx_i2c_timeout(dev);
203 int ret;
204
205 if (len < 1 || len > 64)
206 return -EOPNOTSUPP;
207 /*
208 * NOTE: limited by the USB ctrl message constraints
209 * Zero length reads always succeed, even if no device is connected
210 */
211
212 /* Write to i2c device */
213 ret = dev->em28xx_write_regs_req(dev, stop ? 2 : 3, addr, buf, len);
214 if (ret != len) {
215 if (ret < 0) {
216 dev_warn(&dev->intf->dev,
217 "writing to i2c device at 0x%x failed (error=%i)\n",
218 addr, ret);
219 return ret;
220 }
221 dev_warn(&dev->intf->dev,
222 "%i bytes write to i2c device at 0x%x requested, but %i bytes written\n",
223 len, addr, ret);
224 return -EIO;
225 }
226
227 /* wait for completion */
228 while (time_is_after_jiffies(timeout)) {
229 ret = dev->em28xx_read_reg(dev, 0x05);
230 if (ret == 0) /* success */
231 return len;
232 if (ret == 0x10) {
233 dprintk(1, "I2C ACK error on writing to addr 0x%02x\n",
234 addr);
235 return -ENXIO;
236 }
237 if (ret < 0) {
238 dev_warn(&dev->intf->dev,
239 "failed to get i2c transfer status from bridge register (error=%i)\n",
240 ret);
241 return ret;
242 }
243 usleep_range(min: 5000, max: 6000);
244 /*
245 * NOTE: do we really have to wait for success ?
246 * Never seen anything else than 0x00 or 0x10
247 * (even with high payload) ...
248 */
249 }
250
251 if (ret == 0x02 || ret == 0x04) {
252 /* NOTE: these errors seem to be related to clock stretching */
253 dprintk(0,
254 "write to i2c device at 0x%x timed out (status=%i)\n",
255 addr, ret);
256 return -ETIMEDOUT;
257 }
258
259 dev_warn(&dev->intf->dev,
260 "write to i2c device at 0x%x failed with unknown error (status=%i)\n",
261 addr, ret);
262 return -EIO;
263}
264
265/*
266 * em28xx_i2c_recv_bytes()
267 * read a byte from the i2c device
268 */
269static int em28xx_i2c_recv_bytes(struct em28xx *dev, u16 addr, u8 *buf, u16 len)
270{
271 int ret;
272
273 if (len < 1 || len > 64)
274 return -EOPNOTSUPP;
275 /*
276 * NOTE: limited by the USB ctrl message constraints
277 * Zero length reads always succeed, even if no device is connected
278 */
279
280 /* Read data from i2c device */
281 ret = dev->em28xx_read_reg_req_len(dev, 2, addr, buf, len);
282 if (ret < 0) {
283 dev_warn(&dev->intf->dev,
284 "reading from i2c device at 0x%x failed (error=%i)\n",
285 addr, ret);
286 return ret;
287 } else if (ret != len) {
288 dev_dbg(&dev->intf->dev,
289 "%i bytes read from i2c device at 0x%x requested, but %i bytes written\n",
290 ret, addr, len);
291 }
292 /*
293 * NOTE: some devices with two i2c buses have the bad habit to return 0
294 * bytes if we are on bus B AND there was no write attempt to the
295 * specified slave address before AND no device is present at the
296 * requested slave address.
297 * Anyway, the next check will fail with -ENXIO in this case, so avoid
298 * spamming the system log on device probing and do nothing here.
299 */
300
301 /* Check success of the i2c operation */
302 ret = dev->em28xx_read_reg(dev, 0x05);
303 if (ret == 0) /* success */
304 return len;
305 if (ret < 0) {
306 dev_warn(&dev->intf->dev,
307 "failed to get i2c transfer status from bridge register (error=%i)\n",
308 ret);
309 return ret;
310 }
311 if (ret == 0x10) {
312 dprintk(1, "I2C ACK error on writing to addr 0x%02x\n",
313 addr);
314 return -ENXIO;
315 }
316
317 if (ret == 0x02 || ret == 0x04) {
318 /* NOTE: these errors seem to be related to clock stretching */
319 dprintk(0,
320 "write to i2c device at 0x%x timed out (status=%i)\n",
321 addr, ret);
322 return -ETIMEDOUT;
323 }
324
325 dev_warn(&dev->intf->dev,
326 "read from i2c device at 0x%x failed with unknown error (status=%i)\n",
327 addr, ret);
328 return -EIO;
329}
330
331/*
332 * em28xx_i2c_check_for_device()
333 * check if there is a i2c_device at the supplied address
334 */
335static int em28xx_i2c_check_for_device(struct em28xx *dev, u16 addr)
336{
337 int ret;
338 u8 buf;
339
340 ret = em28xx_i2c_recv_bytes(dev, addr, buf: &buf, len: 1);
341 if (ret == 1)
342 return 0;
343 return (ret < 0) ? ret : -EIO;
344}
345
346/*
347 * em25xx_bus_B_send_bytes
348 * write bytes to the i2c device
349 */
350static int em25xx_bus_B_send_bytes(struct em28xx *dev, u16 addr, u8 *buf,
351 u16 len)
352{
353 int ret;
354
355 if (len < 1 || len > 64)
356 return -EOPNOTSUPP;
357 /*
358 * NOTE: limited by the USB ctrl message constraints
359 * Zero length reads always succeed, even if no device is connected
360 */
361
362 /* Set register and write value */
363 ret = dev->em28xx_write_regs_req(dev, 0x06, addr, buf, len);
364 if (ret != len) {
365 if (ret < 0) {
366 dev_warn(&dev->intf->dev,
367 "writing to i2c device at 0x%x failed (error=%i)\n",
368 addr, ret);
369 return ret;
370 }
371
372 dev_warn(&dev->intf->dev,
373 "%i bytes write to i2c device at 0x%x requested, but %i bytes written\n",
374 len, addr, ret);
375 return -EIO;
376 }
377 /* Check success */
378 ret = dev->em28xx_read_reg_req(dev, 0x08, 0x0000);
379 /*
380 * NOTE: the only error we've seen so far is
381 * 0x01 when the slave device is not present
382 */
383 if (!ret)
384 return len;
385
386 if (ret > 0) {
387 dprintk(1, "Bus B R08 returned 0x%02x: I2C ACK error\n", ret);
388 return -ENXIO;
389 }
390
391 return ret;
392 /*
393 * NOTE: With chip types (other chip IDs) which actually don't support
394 * this operation, it seems to succeed ALWAYS ! (even if there is no
395 * slave device or even no second i2c bus provided)
396 */
397}
398
399/*
400 * em25xx_bus_B_recv_bytes
401 * read bytes from the i2c device
402 */
403static int em25xx_bus_B_recv_bytes(struct em28xx *dev, u16 addr, u8 *buf,
404 u16 len)
405{
406 int ret;
407
408 if (len < 1 || len > 64)
409 return -EOPNOTSUPP;
410 /*
411 * NOTE: limited by the USB ctrl message constraints
412 * Zero length reads always succeed, even if no device is connected
413 */
414
415 /* Read value */
416 ret = dev->em28xx_read_reg_req_len(dev, 0x06, addr, buf, len);
417 if (ret < 0) {
418 dev_warn(&dev->intf->dev,
419 "reading from i2c device at 0x%x failed (error=%i)\n",
420 addr, ret);
421 return ret;
422 }
423 /*
424 * NOTE: some devices with two i2c buses have the bad habit to return 0
425 * bytes if we are on bus B AND there was no write attempt to the
426 * specified slave address before AND no device is present at the
427 * requested slave address.
428 * Anyway, the next check will fail with -ENXIO in this case, so avoid
429 * spamming the system log on device probing and do nothing here.
430 */
431
432 /* Check success */
433 ret = dev->em28xx_read_reg_req(dev, 0x08, 0x0000);
434 /*
435 * NOTE: the only error we've seen so far is
436 * 0x01 when the slave device is not present
437 */
438 if (!ret)
439 return len;
440
441 if (ret > 0) {
442 dprintk(1, "Bus B R08 returned 0x%02x: I2C ACK error\n", ret);
443 return -ENXIO;
444 }
445
446 return ret;
447 /*
448 * NOTE: With chip types (other chip IDs) which actually don't support
449 * this operation, it seems to succeed ALWAYS ! (even if there is no
450 * slave device or even no second i2c bus provided)
451 */
452}
453
454/*
455 * em25xx_bus_B_check_for_device()
456 * check if there is a i2c device at the supplied address
457 */
458static int em25xx_bus_B_check_for_device(struct em28xx *dev, u16 addr)
459{
460 u8 buf;
461 int ret;
462
463 ret = em25xx_bus_B_recv_bytes(dev, addr, buf: &buf, len: 1);
464 if (ret < 0)
465 return ret;
466
467 return 0;
468 /*
469 * NOTE: With chips which do not support this operation,
470 * it seems to succeed ALWAYS ! (even if no device connected)
471 */
472}
473
474static inline int i2c_check_for_device(struct em28xx_i2c_bus *i2c_bus, u16 addr)
475{
476 struct em28xx *dev = i2c_bus->dev;
477 int rc = -EOPNOTSUPP;
478
479 if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM28XX)
480 rc = em28xx_i2c_check_for_device(dev, addr);
481 else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM2800)
482 rc = em2800_i2c_check_for_device(dev, addr);
483 else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM25XX_BUS_B)
484 rc = em25xx_bus_B_check_for_device(dev, addr);
485 return rc;
486}
487
488static inline int i2c_recv_bytes(struct em28xx_i2c_bus *i2c_bus,
489 struct i2c_msg msg)
490{
491 struct em28xx *dev = i2c_bus->dev;
492 u16 addr = msg.addr << 1;
493 int rc = -EOPNOTSUPP;
494
495 if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM28XX)
496 rc = em28xx_i2c_recv_bytes(dev, addr, buf: msg.buf, len: msg.len);
497 else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM2800)
498 rc = em2800_i2c_recv_bytes(dev, addr, buf: msg.buf, len: msg.len);
499 else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM25XX_BUS_B)
500 rc = em25xx_bus_B_recv_bytes(dev, addr, buf: msg.buf, len: msg.len);
501 return rc;
502}
503
504static inline int i2c_send_bytes(struct em28xx_i2c_bus *i2c_bus,
505 struct i2c_msg msg, int stop)
506{
507 struct em28xx *dev = i2c_bus->dev;
508 u16 addr = msg.addr << 1;
509 int rc = -EOPNOTSUPP;
510
511 if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM28XX)
512 rc = em28xx_i2c_send_bytes(dev, addr, buf: msg.buf, len: msg.len, stop);
513 else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM2800)
514 rc = em2800_i2c_send_bytes(dev, addr, buf: msg.buf, len: msg.len);
515 else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM25XX_BUS_B)
516 rc = em25xx_bus_B_send_bytes(dev, addr, buf: msg.buf, len: msg.len);
517 return rc;
518}
519
520/*
521 * em28xx_i2c_xfer()
522 * the main i2c transfer function
523 */
524static int em28xx_i2c_xfer(struct i2c_adapter *i2c_adap,
525 struct i2c_msg msgs[], int num)
526{
527 struct em28xx_i2c_bus *i2c_bus = i2c_adap->algo_data;
528 struct em28xx *dev = i2c_bus->dev;
529 unsigned int bus = i2c_bus->bus;
530 int addr, rc, i;
531 u8 reg;
532
533 /*
534 * prevent i2c xfer attempts after device is disconnected
535 * some fe's try to do i2c writes/reads from their release
536 * interfaces when called in disconnect path
537 */
538 if (dev->disconnected)
539 return -ENODEV;
540
541 if (!rt_mutex_trylock(lock: &dev->i2c_bus_lock))
542 return -EAGAIN;
543
544 /* Switch I2C bus if needed */
545 if (bus != dev->cur_i2c_bus &&
546 i2c_bus->algo_type == EM28XX_I2C_ALGO_EM28XX) {
547 if (bus == 1)
548 reg = EM2874_I2C_SECONDARY_BUS_SELECT;
549 else
550 reg = 0;
551 em28xx_write_reg_bits(dev, EM28XX_R06_I2C_CLK, val: reg,
552 EM2874_I2C_SECONDARY_BUS_SELECT);
553 dev->cur_i2c_bus = bus;
554 }
555
556 for (i = 0; i < num; i++) {
557 addr = msgs[i].addr << 1;
558 if (!msgs[i].len) {
559 /*
560 * no len: check only for device presence
561 * This code is only called during device probe.
562 */
563 rc = i2c_check_for_device(i2c_bus, addr);
564
565 if (rc == -ENXIO)
566 rc = -ENODEV;
567 } else if (msgs[i].flags & I2C_M_RD) {
568 /* read bytes */
569 rc = i2c_recv_bytes(i2c_bus, msg: msgs[i]);
570 } else {
571 /* write bytes */
572 rc = i2c_send_bytes(i2c_bus, msg: msgs[i], stop: i == num - 1);
573 }
574
575 if (rc < 0)
576 goto error;
577
578 dprintk(2, "%s %s addr=%02x len=%d: %*ph\n",
579 (msgs[i].flags & I2C_M_RD) ? "read" : "write",
580 i == num - 1 ? "stop" : "nonstop",
581 addr, msgs[i].len,
582 msgs[i].len, msgs[i].buf);
583 }
584
585 rt_mutex_unlock(lock: &dev->i2c_bus_lock);
586 return num;
587
588error:
589 dprintk(2, "%s %s addr=%02x len=%d: %sERROR: %i\n",
590 (msgs[i].flags & I2C_M_RD) ? "read" : "write",
591 i == num - 1 ? "stop" : "nonstop",
592 addr, msgs[i].len,
593 (rc == -ENODEV) ? "no device " : "",
594 rc);
595
596 rt_mutex_unlock(lock: &dev->i2c_bus_lock);
597 return rc;
598}
599
600/*
601 * based on linux/sunrpc/svcauth.h and linux/hash.h
602 * The original hash function returns a different value, if arch is x86_64
603 * or i386.
604 */
605static inline unsigned long em28xx_hash_mem(char *buf, int length, int bits)
606{
607 unsigned long hash = 0;
608 unsigned long l = 0;
609 int len = 0;
610 unsigned char c;
611
612 do {
613 if (len == length) {
614 c = (char)len;
615 len = -1;
616 } else {
617 c = *buf++;
618 }
619 l = (l << 8) | c;
620 len++;
621 if ((len & (32 / 8 - 1)) == 0)
622 hash = ((hash ^ l) * 0x9e370001UL);
623 } while (len);
624
625 return (hash >> (32 - bits)) & 0xffffffffUL;
626}
627
628/*
629 * Helper function to read data blocks from i2c clients with 8 or 16 bit
630 * address width, 8 bit register width and auto incrementation been activated
631 */
632static int em28xx_i2c_read_block(struct em28xx *dev, unsigned int bus, u16 addr,
633 bool addr_w16, u16 len, u8 *data)
634{
635 int remain = len, rsize, rsize_max, ret;
636 u8 buf[2];
637
638 /* Sanity check */
639 if (addr + remain > (addr_w16 * 0xff00 + 0xff + 1))
640 return -EINVAL;
641 /* Select address */
642 buf[0] = addr >> 8;
643 buf[1] = addr & 0xff;
644 ret = i2c_master_send(client: &dev->i2c_client[bus],
645 buf: buf + !addr_w16, count: 1 + addr_w16);
646 if (ret < 0)
647 return ret;
648 /* Read data */
649 if (dev->board.is_em2800)
650 rsize_max = 4;
651 else
652 rsize_max = 64;
653 while (remain > 0) {
654 if (remain > rsize_max)
655 rsize = rsize_max;
656 else
657 rsize = remain;
658
659 ret = i2c_master_recv(client: &dev->i2c_client[bus], buf: data, count: rsize);
660 if (ret < 0)
661 return ret;
662
663 remain -= rsize;
664 data += rsize;
665 }
666
667 return len;
668}
669
670static int em28xx_i2c_eeprom(struct em28xx *dev, unsigned int bus,
671 u8 **eedata, u16 *eedata_len)
672{
673 const u16 len = 256;
674 /*
675 * FIXME common length/size for bytes to read, to display, hash
676 * calculation and returned device dataset. Simplifies the code a lot,
677 * but we might have to deal with multiple sizes in the future !
678 */
679 int err;
680 struct em28xx_eeprom *dev_config;
681 u8 buf, *data;
682
683 *eedata = NULL;
684 *eedata_len = 0;
685
686 /* EEPROM is always on i2c bus 0 on all known devices. */
687
688 dev->i2c_client[bus].addr = 0xa0 >> 1;
689
690 /* Check if board has eeprom */
691 err = i2c_master_recv(client: &dev->i2c_client[bus], buf: &buf, count: 0);
692 if (err < 0) {
693 dev_info(&dev->intf->dev, "board has no eeprom\n");
694 return -ENODEV;
695 }
696
697 data = kzalloc(size: len, GFP_KERNEL);
698 if (!data)
699 return -ENOMEM;
700
701 /* Read EEPROM content */
702 err = em28xx_i2c_read_block(dev, bus, addr: 0x0000,
703 addr_w16: dev->eeprom_addrwidth_16bit,
704 len, data);
705 if (err != len) {
706 dev_err(&dev->intf->dev,
707 "failed to read eeprom (err=%d)\n", err);
708 goto error;
709 }
710
711 if (i2c_debug) {
712 /* Display eeprom content */
713 print_hex_dump(KERN_DEBUG, prefix_str: "em28xx eeprom ", prefix_type: DUMP_PREFIX_OFFSET,
714 rowsize: 16, groupsize: 1, buf: data, len, ascii: true);
715
716 if (dev->eeprom_addrwidth_16bit)
717 dev_info(&dev->intf->dev,
718 "eeprom %06x: ... (skipped)\n", 256);
719 }
720
721 if (dev->eeprom_addrwidth_16bit &&
722 data[0] == 0x26 && data[3] == 0x00) {
723 /* new eeprom format; size 4-64kb */
724 u16 mc_start;
725 u16 hwconf_offset;
726
727 dev->hash = em28xx_hash_mem(buf: data, length: len, bits: 32);
728 mc_start = (data[1] << 8) + 4; /* usually 0x0004 */
729
730 dev_info(&dev->intf->dev,
731 "EEPROM ID = %4ph, EEPROM hash = 0x%08lx\n",
732 data, dev->hash);
733 dev_info(&dev->intf->dev,
734 "EEPROM info:\n");
735 dev_info(&dev->intf->dev,
736 "\tmicrocode start address = 0x%04x, boot configuration = 0x%02x\n",
737 mc_start, data[2]);
738 /*
739 * boot configuration (address 0x0002):
740 * [0] microcode download speed: 1 = 400 kHz; 0 = 100 kHz
741 * [1] always selects 12 kb RAM
742 * [2] USB device speed: 1 = force Full Speed; 0 = auto detect
743 * [4] 1 = force fast mode and no suspend for device testing
744 * [5:7] USB PHY tuning registers; determined by device
745 * characterization
746 */
747
748 /*
749 * Read hardware config dataset offset from address
750 * (microcode start + 46)
751 */
752 err = em28xx_i2c_read_block(dev, bus, addr: mc_start + 46, addr_w16: 1, len: 2,
753 data);
754 if (err != 2) {
755 dev_err(&dev->intf->dev,
756 "failed to read hardware configuration data from eeprom (err=%d)\n",
757 err);
758 goto error;
759 }
760
761 /* Calculate hardware config dataset start address */
762 hwconf_offset = mc_start + data[0] + (data[1] << 8);
763
764 /* Read hardware config dataset */
765 /*
766 * NOTE: the microcode copy can be multiple pages long, but
767 * we assume the hardware config dataset is the same as in
768 * the old eeprom and not longer than 256 bytes.
769 * tveeprom is currently also limited to 256 bytes.
770 */
771 err = em28xx_i2c_read_block(dev, bus, addr: hwconf_offset, addr_w16: 1, len,
772 data);
773 if (err != len) {
774 dev_err(&dev->intf->dev,
775 "failed to read hardware configuration data from eeprom (err=%d)\n",
776 err);
777 goto error;
778 }
779
780 /* Verify hardware config dataset */
781 /* NOTE: not all devices provide this type of dataset */
782 if (data[0] != 0x1a || data[1] != 0xeb ||
783 data[2] != 0x67 || data[3] != 0x95) {
784 dev_info(&dev->intf->dev,
785 "\tno hardware configuration dataset found in eeprom\n");
786 kfree(objp: data);
787 return 0;
788 }
789
790 /*
791 * TODO: decrypt eeprom data for camera bridges
792 * (em25xx, em276x+)
793 */
794
795 } else if (!dev->eeprom_addrwidth_16bit &&
796 data[0] == 0x1a && data[1] == 0xeb &&
797 data[2] == 0x67 && data[3] == 0x95) {
798 dev->hash = em28xx_hash_mem(buf: data, length: len, bits: 32);
799 dev_info(&dev->intf->dev,
800 "EEPROM ID = %4ph, EEPROM hash = 0x%08lx\n",
801 data, dev->hash);
802 dev_info(&dev->intf->dev,
803 "EEPROM info:\n");
804 } else {
805 dev_info(&dev->intf->dev,
806 "unknown eeprom format or eeprom corrupted !\n");
807 err = -ENODEV;
808 goto error;
809 }
810
811 *eedata = data;
812 *eedata_len = len;
813 dev_config = (void *)*eedata;
814
815 switch (le16_to_cpu(dev_config->chip_conf) >> 4 & 0x3) {
816 case 0:
817 dev_info(&dev->intf->dev, "\tNo audio on board.\n");
818 break;
819 case 1:
820 dev_info(&dev->intf->dev, "\tAC97 audio (5 sample rates)\n");
821 break;
822 case 2:
823 if (dev->chip_id < CHIP_ID_EM2860)
824 dev_info(&dev->intf->dev,
825 "\tI2S audio, sample rate=32k\n");
826 else
827 dev_info(&dev->intf->dev,
828 "\tI2S audio, 3 sample rates\n");
829 break;
830 case 3:
831 if (dev->chip_id < CHIP_ID_EM2860)
832 dev_info(&dev->intf->dev,
833 "\tI2S audio, 3 sample rates\n");
834 else
835 dev_info(&dev->intf->dev,
836 "\tI2S audio, 5 sample rates\n");
837 break;
838 }
839
840 if (le16_to_cpu(dev_config->chip_conf) & 1 << 3)
841 dev_info(&dev->intf->dev, "\tUSB Remote wakeup capable\n");
842
843 if (le16_to_cpu(dev_config->chip_conf) & 1 << 2)
844 dev_info(&dev->intf->dev, "\tUSB Self power capable\n");
845
846 switch (le16_to_cpu(dev_config->chip_conf) & 0x3) {
847 case 0:
848 dev_info(&dev->intf->dev, "\t500mA max power\n");
849 break;
850 case 1:
851 dev_info(&dev->intf->dev, "\t400mA max power\n");
852 break;
853 case 2:
854 dev_info(&dev->intf->dev, "\t300mA max power\n");
855 break;
856 case 3:
857 dev_info(&dev->intf->dev, "\t200mA max power\n");
858 break;
859 }
860 dev_info(&dev->intf->dev,
861 "\tTable at offset 0x%02x, strings=0x%04x, 0x%04x, 0x%04x\n",
862 dev_config->string_idx_table,
863 le16_to_cpu(dev_config->string1),
864 le16_to_cpu(dev_config->string2),
865 le16_to_cpu(dev_config->string3));
866
867 return 0;
868
869error:
870 kfree(objp: data);
871 return err;
872}
873
874/* ----------------------------------------------------------- */
875
876/*
877 * functionality()
878 */
879static u32 functionality(struct i2c_adapter *i2c_adap)
880{
881 struct em28xx_i2c_bus *i2c_bus = i2c_adap->algo_data;
882
883 if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM28XX ||
884 i2c_bus->algo_type == EM28XX_I2C_ALGO_EM25XX_BUS_B) {
885 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
886 } else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM2800) {
887 return (I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL) &
888 ~I2C_FUNC_SMBUS_WRITE_BLOCK_DATA;
889 }
890
891 WARN(1, "Unknown i2c bus algorithm.\n");
892 return 0;
893}
894
895static const struct i2c_algorithm em28xx_algo = {
896 .master_xfer = em28xx_i2c_xfer,
897 .functionality = functionality,
898};
899
900static const struct i2c_adapter em28xx_adap_template = {
901 .owner = THIS_MODULE,
902 .name = "em28xx",
903 .algo = &em28xx_algo,
904};
905
906static const struct i2c_client em28xx_client_template = {
907 .name = "em28xx internal",
908};
909
910/* ----------------------------------------------------------- */
911
912/*
913 * i2c_devs
914 * incomplete list of known devices
915 */
916static char *i2c_devs[128] = {
917 [0x1c >> 1] = "lgdt330x",
918 [0x3e >> 1] = "remote IR sensor",
919 [0x4a >> 1] = "saa7113h",
920 [0x52 >> 1] = "drxk",
921 [0x60 >> 1] = "remote IR sensor",
922 [0x8e >> 1] = "remote IR sensor",
923 [0x86 >> 1] = "tda9887",
924 [0x80 >> 1] = "msp34xx",
925 [0x88 >> 1] = "msp34xx",
926 [0xa0 >> 1] = "eeprom",
927 [0xb0 >> 1] = "tda9874",
928 [0xb8 >> 1] = "tvp5150a",
929 [0xba >> 1] = "webcam sensor or tvp5150a",
930 [0xc0 >> 1] = "tuner (analog)",
931 [0xc2 >> 1] = "tuner (analog)",
932 [0xc4 >> 1] = "tuner (analog)",
933 [0xc6 >> 1] = "tuner (analog)",
934};
935
936/*
937 * do_i2c_scan()
938 * check i2c address range for devices
939 */
940void em28xx_do_i2c_scan(struct em28xx *dev, unsigned int bus)
941{
942 u8 i2c_devicelist[128];
943 unsigned char buf;
944 int i, rc;
945
946 memset(i2c_devicelist, 0, sizeof(i2c_devicelist));
947
948 for (i = 0; i < ARRAY_SIZE(i2c_devs); i++) {
949 dev->i2c_client[bus].addr = i;
950 rc = i2c_master_recv(client: &dev->i2c_client[bus], buf: &buf, count: 0);
951 if (rc < 0)
952 continue;
953 i2c_devicelist[i] = i;
954 dev_info(&dev->intf->dev,
955 "found i2c device @ 0x%x on bus %d [%s]\n",
956 i << 1, bus, i2c_devs[i] ? i2c_devs[i] : "???");
957 }
958
959 if (bus == dev->def_i2c_bus)
960 dev->i2c_hash = em28xx_hash_mem(buf: i2c_devicelist,
961 length: sizeof(i2c_devicelist), bits: 32);
962}
963
964/*
965 * em28xx_i2c_register()
966 * register i2c bus
967 */
968int em28xx_i2c_register(struct em28xx *dev, unsigned int bus,
969 enum em28xx_i2c_algo_type algo_type)
970{
971 int retval;
972
973 if (WARN_ON(!dev->em28xx_write_regs || !dev->em28xx_read_reg ||
974 !dev->em28xx_write_regs_req || !dev->em28xx_read_reg_req))
975 return -ENODEV;
976
977 if (bus >= NUM_I2C_BUSES)
978 return -ENODEV;
979
980 dev->i2c_adap[bus] = em28xx_adap_template;
981 dev->i2c_adap[bus].dev.parent = &dev->intf->dev;
982 strscpy(dev->i2c_adap[bus].name, dev_name(&dev->intf->dev),
983 sizeof(dev->i2c_adap[bus].name));
984
985 dev->i2c_bus[bus].bus = bus;
986 dev->i2c_bus[bus].algo_type = algo_type;
987 dev->i2c_bus[bus].dev = dev;
988 dev->i2c_adap[bus].algo_data = &dev->i2c_bus[bus];
989
990 retval = i2c_add_adapter(adap: &dev->i2c_adap[bus]);
991 if (retval < 0) {
992 dev_err(&dev->intf->dev,
993 "%s: i2c_add_adapter failed! retval [%d]\n",
994 __func__, retval);
995 return retval;
996 }
997
998 dev->i2c_client[bus] = em28xx_client_template;
999 dev->i2c_client[bus].adapter = &dev->i2c_adap[bus];
1000
1001 /* Up to now, all eeproms are at bus 0 */
1002 if (!bus) {
1003 retval = em28xx_i2c_eeprom(dev, bus,
1004 eedata: &dev->eedata, eedata_len: &dev->eedata_len);
1005 if (retval < 0 && retval != -ENODEV) {
1006 dev_err(&dev->intf->dev,
1007 "%s: em28xx_i2_eeprom failed! retval [%d]\n",
1008 __func__, retval);
1009 }
1010 }
1011
1012 if (i2c_scan)
1013 em28xx_do_i2c_scan(dev, bus);
1014
1015 return 0;
1016}
1017
1018/*
1019 * em28xx_i2c_unregister()
1020 * unregister i2c_bus
1021 */
1022int em28xx_i2c_unregister(struct em28xx *dev, unsigned int bus)
1023{
1024 if (bus >= NUM_I2C_BUSES)
1025 return -ENODEV;
1026
1027 i2c_del_adapter(adap: &dev->i2c_adap[bus]);
1028 return 0;
1029}
1030

source code of linux/drivers/media/usb/em28xx/em28xx-i2c.c