1 /*
2    em28xx-i2c.c - driver for Empia EM2800/EM2820/2840 USB video capture devices
3 
4    Copyright (C) 2005 Ludovico Cavedon <cavedon@sssup.it>
5 		      Markus Rechberger <mrechberger@gmail.com>
6 		      Mauro Carvalho Chehab <mchehab@infradead.org>
7 		      Sascha Sommer <saschasommer@freenet.de>
8    Copyright (C) 2013 Frank Schäfer <fschaefer.oss@googlemail.com>
9 
10    This program is free software; you can redistribute it and/or modify
11    it under the terms of the GNU General Public License as published by
12    the Free Software Foundation; either version 2 of the License, or
13    (at your option) any later version.
14 
15    This program is distributed in the hope that it will be useful,
16    but WITHOUT ANY WARRANTY; without even the implied warranty of
17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18    GNU General Public License for more details.
19 
20    You should have received a copy of the GNU General Public License
21    along with this program; if not, write to the Free Software
22    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
23  */
24 
25 #include <linux/module.h>
26 #include <linux/kernel.h>
27 #include <linux/usb.h>
28 #include <linux/i2c.h>
29 
30 #include "em28xx.h"
31 #include "tuner-xc2028.h"
32 #include <media/v4l2-common.h>
33 #include <media/tuner.h>
34 
35 /* ----------------------------------------------------------- */
36 
37 static unsigned int i2c_scan;
38 module_param(i2c_scan, int, 0444);
39 MODULE_PARM_DESC(i2c_scan, "scan i2c bus at insmod time");
40 
41 static unsigned int i2c_debug;
42 module_param(i2c_debug, int, 0644);
43 MODULE_PARM_DESC(i2c_debug, "enable debug messages [i2c]");
44 
45 /*
46  * em2800_i2c_send_bytes()
47  * send up to 4 bytes to the em2800 i2c device
48  */
49 static int em2800_i2c_send_bytes(struct em28xx *dev, u8 addr, u8 *buf, u16 len)
50 {
51 	int ret;
52 	int write_timeout;
53 	u8 b2[6];
54 
55 	if (len < 1 || len > 4)
56 		return -EOPNOTSUPP;
57 
58 	BUG_ON(len < 1 || len > 4);
59 	b2[5] = 0x80 + len - 1;
60 	b2[4] = addr;
61 	b2[3] = buf[0];
62 	if (len > 1)
63 		b2[2] = buf[1];
64 	if (len > 2)
65 		b2[1] = buf[2];
66 	if (len > 3)
67 		b2[0] = buf[3];
68 
69 	/* trigger write */
70 	ret = dev->em28xx_write_regs(dev, 4 - len, &b2[4 - len], 2 + len);
71 	if (ret != 2 + len) {
72 		em28xx_warn("failed to trigger write to i2c address 0x%x (error=%i)\n",
73 			    addr, ret);
74 		return (ret < 0) ? ret : -EIO;
75 	}
76 	/* wait for completion */
77 	for (write_timeout = EM2800_I2C_XFER_TIMEOUT; write_timeout > 0;
78 	     write_timeout -= 5) {
79 		ret = dev->em28xx_read_reg(dev, 0x05);
80 		if (ret == 0x80 + len - 1) {
81 			return len;
82 		} else if (ret == 0x94 + len - 1) {
83 			return -ENODEV;
84 		} else if (ret < 0) {
85 			em28xx_warn("failed to get i2c transfer status from bridge register (error=%i)\n",
86 				    ret);
87 			return ret;
88 		}
89 		msleep(5);
90 	}
91 	em28xx_warn("write to i2c device at 0x%x timed out\n", addr);
92 	return -EIO;
93 }
94 
95 /*
96  * em2800_i2c_recv_bytes()
97  * read up to 4 bytes from the em2800 i2c device
98  */
99 static int em2800_i2c_recv_bytes(struct em28xx *dev, u8 addr, u8 *buf, u16 len)
100 {
101 	u8 buf2[4];
102 	int ret;
103 	int read_timeout;
104 	int i;
105 
106 	if (len < 1 || len > 4)
107 		return -EOPNOTSUPP;
108 
109 	/* trigger read */
110 	buf2[1] = 0x84 + len - 1;
111 	buf2[0] = addr;
112 	ret = dev->em28xx_write_regs(dev, 0x04, buf2, 2);
113 	if (ret != 2) {
114 		em28xx_warn("failed to trigger read from i2c address 0x%x (error=%i)\n",
115 			    addr, ret);
116 		return (ret < 0) ? ret : -EIO;
117 	}
118 
119 	/* wait for completion */
120 	for (read_timeout = EM2800_I2C_XFER_TIMEOUT; read_timeout > 0;
121 	     read_timeout -= 5) {
122 		ret = dev->em28xx_read_reg(dev, 0x05);
123 		if (ret == 0x84 + len - 1) {
124 			break;
125 		} else if (ret == 0x94 + len - 1) {
126 			return -ENODEV;
127 		} else if (ret < 0) {
128 			em28xx_warn("failed to get i2c transfer status from bridge register (error=%i)\n",
129 				    ret);
130 			return ret;
131 		}
132 		msleep(5);
133 	}
134 	if (ret != 0x84 + len - 1)
135 		em28xx_warn("read from i2c device at 0x%x timed out\n", addr);
136 
137 	/* get the received message */
138 	ret = dev->em28xx_read_reg_req_len(dev, 0x00, 4-len, buf2, len);
139 	if (ret != len) {
140 		em28xx_warn("reading from i2c device at 0x%x failed: couldn't get the received message from the bridge (error=%i)\n",
141 			    addr, ret);
142 		return (ret < 0) ? ret : -EIO;
143 	}
144 	for (i = 0; i < len; i++)
145 		buf[i] = buf2[len - 1 - i];
146 
147 	return ret;
148 }
149 
150 /*
151  * em2800_i2c_check_for_device()
152  * check if there is an i2c device at the supplied address
153  */
154 static int em2800_i2c_check_for_device(struct em28xx *dev, u8 addr)
155 {
156 	u8 buf;
157 	int ret;
158 
159 	ret = em2800_i2c_recv_bytes(dev, addr, &buf, 1);
160 	if (ret == 1)
161 		return 0;
162 	return (ret < 0) ? ret : -EIO;
163 }
164 
165 /*
166  * em28xx_i2c_send_bytes()
167  */
168 static int em28xx_i2c_send_bytes(struct em28xx *dev, u16 addr, u8 *buf,
169 				 u16 len, int stop)
170 {
171 	int write_timeout, ret;
172 
173 	if (len < 1 || len > 64)
174 		return -EOPNOTSUPP;
175 	/*
176 	 * NOTE: limited by the USB ctrl message constraints
177 	 * Zero length reads always succeed, even if no device is connected
178 	 */
179 
180 	/* Write to i2c device */
181 	ret = dev->em28xx_write_regs_req(dev, stop ? 2 : 3, addr, buf, len);
182 	if (ret != len) {
183 		if (ret < 0) {
184 			em28xx_warn("writing to i2c device at 0x%x failed (error=%i)\n",
185 				    addr, ret);
186 			return ret;
187 		} else {
188 			em28xx_warn("%i bytes write to i2c device at 0x%x requested, but %i bytes written\n",
189 				    len, addr, ret);
190 			return -EIO;
191 		}
192 	}
193 
194 	/* Check success of the i2c operation */
195 	for (write_timeout = EM2800_I2C_XFER_TIMEOUT; write_timeout > 0;
196 	     write_timeout -= 5) {
197 		ret = dev->em28xx_read_reg(dev, 0x05);
198 		if (ret == 0) { /* success */
199 			return len;
200 		} else if (ret == 0x10) {
201 			return -ENODEV;
202 		} else if (ret < 0) {
203 			em28xx_warn("failed to read i2c transfer status from bridge (error=%i)\n",
204 				    ret);
205 			return ret;
206 		}
207 		msleep(5);
208 		/*
209 		 * NOTE: do we really have to wait for success ?
210 		 * Never seen anything else than 0x00 or 0x10
211 		 * (even with high payload) ...
212 		 */
213 	}
214 	em28xx_warn("write to i2c device at 0x%x timed out\n", addr);
215 	return -EIO;
216 }
217 
218 /*
219  * em28xx_i2c_recv_bytes()
220  * read a byte from the i2c device
221  */
222 static int em28xx_i2c_recv_bytes(struct em28xx *dev, u16 addr, u8 *buf, u16 len)
223 {
224 	int ret;
225 
226 	if (len < 1 || len > 64)
227 		return -EOPNOTSUPP;
228 	/*
229 	 * NOTE: limited by the USB ctrl message constraints
230 	 * Zero length reads always succeed, even if no device is connected
231 	 */
232 
233 	/* Read data from i2c device */
234 	ret = dev->em28xx_read_reg_req_len(dev, 2, addr, buf, len);
235 	if (ret < 0) {
236 		em28xx_warn("reading from i2c device at 0x%x failed (error=%i)\n",
237 			    addr, ret);
238 		return ret;
239 	}
240 	/*
241 	 * NOTE: some devices with two i2c busses have the bad habit to return 0
242 	 * bytes if we are on bus B AND there was no write attempt to the
243 	 * specified slave address before AND no device is present at the
244 	 * requested slave address.
245 	 * Anyway, the next check will fail with -ENODEV in this case, so avoid
246 	 * spamming the system log on device probing and do nothing here.
247 	 */
248 
249 	/* Check success of the i2c operation */
250 	ret = dev->em28xx_read_reg(dev, 0x05);
251 	if (ret < 0) {
252 		em28xx_warn("failed to read i2c transfer status from bridge (error=%i)\n",
253 			    ret);
254 		return ret;
255 	}
256 	if (ret > 0) {
257 		if (ret == 0x10) {
258 			return -ENODEV;
259 		} else {
260 			em28xx_warn("unknown i2c error (status=%i)\n", ret);
261 			return -EIO;
262 		}
263 	}
264 	return len;
265 }
266 
267 /*
268  * em28xx_i2c_check_for_device()
269  * check if there is a i2c_device at the supplied address
270  */
271 static int em28xx_i2c_check_for_device(struct em28xx *dev, u16 addr)
272 {
273 	int ret;
274 	u8 buf;
275 
276 	ret = em28xx_i2c_recv_bytes(dev, addr, &buf, 1);
277 	if (ret == 1)
278 		return 0;
279 	return (ret < 0) ? ret : -EIO;
280 }
281 
282 /*
283  * em25xx_bus_B_send_bytes
284  * write bytes to the i2c device
285  */
286 static int em25xx_bus_B_send_bytes(struct em28xx *dev, u16 addr, u8 *buf,
287 				   u16 len)
288 {
289 	int ret;
290 
291 	if (len < 1 || len > 64)
292 		return -EOPNOTSUPP;
293 	/*
294 	 * NOTE: limited by the USB ctrl message constraints
295 	 * Zero length reads always succeed, even if no device is connected
296 	 */
297 
298 	/* Set register and write value */
299 	ret = dev->em28xx_write_regs_req(dev, 0x06, addr, buf, len);
300 	if (ret != len) {
301 		if (ret < 0) {
302 			em28xx_warn("writing to i2c device at 0x%x failed (error=%i)\n",
303 				    addr, ret);
304 			return ret;
305 		} else {
306 			em28xx_warn("%i bytes write to i2c device at 0x%x requested, but %i bytes written\n",
307 				    len, addr, ret);
308 			return -EIO;
309 		}
310 	}
311 	/* Check success */
312 	ret = dev->em28xx_read_reg_req(dev, 0x08, 0x0000);
313 	/*
314 	 * NOTE: the only error we've seen so far is
315 	 * 0x01 when the slave device is not present
316 	 */
317 	if (!ret)
318 		return len;
319 	else if (ret > 0)
320 		return -ENODEV;
321 
322 	return ret;
323 	/*
324 	 * NOTE: With chip types (other chip IDs) which actually don't support
325 	 * this operation, it seems to succeed ALWAYS ! (even if there is no
326 	 * slave device or even no second i2c bus provided)
327 	 */
328 }
329 
330 /*
331  * em25xx_bus_B_recv_bytes
332  * read bytes from the i2c device
333  */
334 static int em25xx_bus_B_recv_bytes(struct em28xx *dev, u16 addr, u8 *buf,
335 				   u16 len)
336 {
337 	int ret;
338 
339 	if (len < 1 || len > 64)
340 		return -EOPNOTSUPP;
341 	/*
342 	 * NOTE: limited by the USB ctrl message constraints
343 	 * Zero length reads always succeed, even if no device is connected
344 	 */
345 
346 	/* Read value */
347 	ret = dev->em28xx_read_reg_req_len(dev, 0x06, addr, buf, len);
348 	if (ret < 0) {
349 		em28xx_warn("reading from i2c device at 0x%x failed (error=%i)\n",
350 			    addr, ret);
351 		return ret;
352 	}
353 	/*
354 	 * NOTE: some devices with two i2c busses have the bad habit to return 0
355 	 * bytes if we are on bus B AND there was no write attempt to the
356 	 * specified slave address before AND no device is present at the
357 	 * requested slave address.
358 	 * Anyway, the next check will fail with -ENODEV in this case, so avoid
359 	 * spamming the system log on device probing and do nothing here.
360 	 */
361 
362 	/* Check success */
363 	ret = dev->em28xx_read_reg_req(dev, 0x08, 0x0000);
364 	/*
365 	 * NOTE: the only error we've seen so far is
366 	 * 0x01 when the slave device is not present
367 	 */
368 	if (!ret)
369 		return len;
370 	else if (ret > 0)
371 		return -ENODEV;
372 
373 	return ret;
374 	/*
375 	 * NOTE: With chip types (other chip IDs) which actually don't support
376 	 * this operation, it seems to succeed ALWAYS ! (even if there is no
377 	 * slave device or even no second i2c bus provided)
378 	 */
379 }
380 
381 /*
382  * em25xx_bus_B_check_for_device()
383  * check if there is a i2c device at the supplied address
384  */
385 static int em25xx_bus_B_check_for_device(struct em28xx *dev, u16 addr)
386 {
387 	u8 buf;
388 	int ret;
389 
390 	ret = em25xx_bus_B_recv_bytes(dev, addr, &buf, 1);
391 	if (ret < 0)
392 		return ret;
393 
394 	return 0;
395 	/*
396 	 * NOTE: With chips which do not support this operation,
397 	 * it seems to succeed ALWAYS ! (even if no device connected)
398 	 */
399 }
400 
401 static inline int i2c_check_for_device(struct em28xx_i2c_bus *i2c_bus, u16 addr)
402 {
403 	struct em28xx *dev = i2c_bus->dev;
404 	int rc = -EOPNOTSUPP;
405 
406 	if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM28XX)
407 		rc = em28xx_i2c_check_for_device(dev, addr);
408 	else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM2800)
409 		rc = em2800_i2c_check_for_device(dev, addr);
410 	else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM25XX_BUS_B)
411 		rc = em25xx_bus_B_check_for_device(dev, addr);
412 	if (rc == -ENODEV) {
413 		if (i2c_debug)
414 			printk(" no device\n");
415 	}
416 	return rc;
417 }
418 
419 static inline int i2c_recv_bytes(struct em28xx_i2c_bus *i2c_bus,
420 				 struct i2c_msg msg)
421 {
422 	struct em28xx *dev = i2c_bus->dev;
423 	u16 addr = msg.addr << 1;
424 	int byte, rc = -EOPNOTSUPP;
425 
426 	if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM28XX)
427 		rc = em28xx_i2c_recv_bytes(dev, addr, msg.buf, msg.len);
428 	else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM2800)
429 		rc = em2800_i2c_recv_bytes(dev, addr, msg.buf, msg.len);
430 	else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM25XX_BUS_B)
431 		rc = em25xx_bus_B_recv_bytes(dev, addr, msg.buf, msg.len);
432 	if (i2c_debug) {
433 		for (byte = 0; byte < msg.len; byte++)
434 			printk(" %02x", msg.buf[byte]);
435 	}
436 	return rc;
437 }
438 
439 static inline int i2c_send_bytes(struct em28xx_i2c_bus *i2c_bus,
440 				 struct i2c_msg msg, int stop)
441 {
442 	struct em28xx *dev = i2c_bus->dev;
443 	u16 addr = msg.addr << 1;
444 	int byte, rc = -EOPNOTSUPP;
445 
446 	if (i2c_debug) {
447 		for (byte = 0; byte < msg.len; byte++)
448 			printk(" %02x", msg.buf[byte]);
449 	}
450 	if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM28XX)
451 		rc = em28xx_i2c_send_bytes(dev, addr, msg.buf, msg.len, stop);
452 	else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM2800)
453 		rc = em2800_i2c_send_bytes(dev, addr, msg.buf, msg.len);
454 	else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM25XX_BUS_B)
455 		rc = em25xx_bus_B_send_bytes(dev, addr, msg.buf, msg.len);
456 	return rc;
457 }
458 
459 /*
460  * em28xx_i2c_xfer()
461  * the main i2c transfer function
462  */
463 static int em28xx_i2c_xfer(struct i2c_adapter *i2c_adap,
464 			   struct i2c_msg msgs[], int num)
465 {
466 	struct em28xx_i2c_bus *i2c_bus = i2c_adap->algo_data;
467 	struct em28xx *dev = i2c_bus->dev;
468 	unsigned bus = i2c_bus->bus;
469 	int addr, rc, i;
470 	u8 reg;
471 
472 	rc = rt_mutex_trylock(&dev->i2c_bus_lock);
473 	if (rc < 0)
474 		return rc;
475 
476 	/* Switch I2C bus if needed */
477 	if (bus != dev->cur_i2c_bus &&
478 	    i2c_bus->algo_type == EM28XX_I2C_ALGO_EM28XX) {
479 		if (bus == 1)
480 			reg = EM2874_I2C_SECONDARY_BUS_SELECT;
481 		else
482 			reg = 0;
483 		em28xx_write_reg_bits(dev, EM28XX_R06_I2C_CLK, reg,
484 				      EM2874_I2C_SECONDARY_BUS_SELECT);
485 		dev->cur_i2c_bus = bus;
486 	}
487 
488 	if (num <= 0) {
489 		rt_mutex_unlock(&dev->i2c_bus_lock);
490 		return 0;
491 	}
492 	for (i = 0; i < num; i++) {
493 		addr = msgs[i].addr << 1;
494 		if (i2c_debug)
495 			printk(KERN_DEBUG "%s at %s: %s %s addr=%02x len=%d:",
496 			       dev->name, __func__ ,
497 			       (msgs[i].flags & I2C_M_RD) ? "read" : "write",
498 			       i == num - 1 ? "stop" : "nonstop",
499 			       addr, msgs[i].len);
500 		if (!msgs[i].len) { /* no len: check only for device presence */
501 			rc = i2c_check_for_device(i2c_bus, addr);
502 			if (rc == -ENODEV) {
503 				rt_mutex_unlock(&dev->i2c_bus_lock);
504 				return rc;
505 			}
506 		} else if (msgs[i].flags & I2C_M_RD) {
507 			/* read bytes */
508 			rc = i2c_recv_bytes(i2c_bus, msgs[i]);
509 		} else {
510 			/* write bytes */
511 			rc = i2c_send_bytes(i2c_bus, msgs[i], i == num - 1);
512 		}
513 		if (rc < 0) {
514 			if (i2c_debug)
515 				printk(" ERROR: %i\n", rc);
516 			rt_mutex_unlock(&dev->i2c_bus_lock);
517 			return rc;
518 		}
519 		if (i2c_debug)
520 			printk("\n");
521 	}
522 
523 	rt_mutex_unlock(&dev->i2c_bus_lock);
524 	return num;
525 }
526 
527 /*
528  * based on linux/sunrpc/svcauth.h and linux/hash.h
529  * The original hash function returns a different value, if arch is x86_64
530  * or i386.
531  */
532 static inline unsigned long em28xx_hash_mem(char *buf, int length, int bits)
533 {
534 	unsigned long hash = 0;
535 	unsigned long l = 0;
536 	int len = 0;
537 	unsigned char c;
538 	do {
539 		if (len == length) {
540 			c = (char)len;
541 			len = -1;
542 		} else
543 			c = *buf++;
544 		l = (l << 8) | c;
545 		len++;
546 		if ((len & (32 / 8 - 1)) == 0)
547 			hash = ((hash^l) * 0x9e370001UL);
548 	} while (len);
549 
550 	return (hash >> (32 - bits)) & 0xffffffffUL;
551 }
552 
553 /*
554  * Helper function to read data blocks from i2c clients with 8 or 16 bit
555  * address width, 8 bit register width and auto incrementation been activated
556  */
557 static int em28xx_i2c_read_block(struct em28xx *dev, unsigned bus, u16 addr,
558 				 bool addr_w16, u16 len, u8 *data)
559 {
560 	int remain = len, rsize, rsize_max, ret;
561 	u8 buf[2];
562 
563 	/* Sanity check */
564 	if (addr + remain > (addr_w16 * 0xff00 + 0xff + 1))
565 		return -EINVAL;
566 	/* Select address */
567 	buf[0] = addr >> 8;
568 	buf[1] = addr & 0xff;
569 	ret = i2c_master_send(&dev->i2c_client[bus], buf + !addr_w16, 1 + addr_w16);
570 	if (ret < 0)
571 		return ret;
572 	/* Read data */
573 	if (dev->board.is_em2800)
574 		rsize_max = 4;
575 	else
576 		rsize_max = 64;
577 	while (remain > 0) {
578 		if (remain > rsize_max)
579 			rsize = rsize_max;
580 		else
581 			rsize = remain;
582 
583 		ret = i2c_master_recv(&dev->i2c_client[bus], data, rsize);
584 		if (ret < 0)
585 			return ret;
586 
587 		remain -= rsize;
588 		data += rsize;
589 	}
590 
591 	return len;
592 }
593 
594 static int em28xx_i2c_eeprom(struct em28xx *dev, unsigned bus,
595 			     u8 **eedata, u16 *eedata_len)
596 {
597 	const u16 len = 256;
598 	/*
599 	 * FIXME common length/size for bytes to read, to display, hash
600 	 * calculation and returned device dataset. Simplifies the code a lot,
601 	 * but we might have to deal with multiple sizes in the future !
602 	 */
603 	int i, err;
604 	struct em28xx_eeprom *dev_config;
605 	u8 buf, *data;
606 
607 	*eedata = NULL;
608 	*eedata_len = 0;
609 
610 	/* EEPROM is always on i2c bus 0 on all known devices. */
611 
612 	dev->i2c_client[bus].addr = 0xa0 >> 1;
613 
614 	/* Check if board has eeprom */
615 	err = i2c_master_recv(&dev->i2c_client[bus], &buf, 0);
616 	if (err < 0) {
617 		em28xx_info("board has no eeprom\n");
618 		return -ENODEV;
619 	}
620 
621 	data = kzalloc(len, GFP_KERNEL);
622 	if (data == NULL)
623 		return -ENOMEM;
624 
625 	/* Read EEPROM content */
626 	err = em28xx_i2c_read_block(dev, bus, 0x0000,
627 				    dev->eeprom_addrwidth_16bit,
628 				    len, data);
629 	if (err != len) {
630 		em28xx_errdev("failed to read eeprom (err=%d)\n", err);
631 		goto error;
632 	}
633 
634 	/* Display eeprom content */
635 	for (i = 0; i < len; i++) {
636 		if (0 == (i % 16)) {
637 			if (dev->eeprom_addrwidth_16bit)
638 				em28xx_info("i2c eeprom %04x:", i);
639 			else
640 				em28xx_info("i2c eeprom %02x:", i);
641 		}
642 		printk(" %02x", data[i]);
643 		if (15 == (i % 16))
644 			printk("\n");
645 	}
646 	if (dev->eeprom_addrwidth_16bit)
647 		em28xx_info("i2c eeprom %04x: ... (skipped)\n", i);
648 
649 	if (dev->eeprom_addrwidth_16bit &&
650 	    data[0] == 0x26 && data[3] == 0x00) {
651 		/* new eeprom format; size 4-64kb */
652 		u16 mc_start;
653 		u16 hwconf_offset;
654 
655 		dev->hash = em28xx_hash_mem(data, len, 32);
656 		mc_start = (data[1] << 8) + 4;	/* usually 0x0004 */
657 
658 		em28xx_info("EEPROM ID = %02x %02x %02x %02x, EEPROM hash = 0x%08lx\n",
659 			    data[0], data[1], data[2], data[3], dev->hash);
660 		em28xx_info("EEPROM info:\n");
661 		em28xx_info("\tmicrocode start address = 0x%04x, boot configuration = 0x%02x\n",
662 			    mc_start, data[2]);
663 		/*
664 		 * boot configuration (address 0x0002):
665 		 * [0]   microcode download speed: 1 = 400 kHz; 0 = 100 kHz
666 		 * [1]   always selects 12 kb RAM
667 		 * [2]   USB device speed: 1 = force Full Speed; 0 = auto detect
668 		 * [4]   1 = force fast mode and no suspend for device testing
669 		 * [5:7] USB PHY tuning registers; determined by device
670 		 *       characterization
671 		 */
672 
673 		/*
674 		 * Read hardware config dataset offset from address
675 		 * (microcode start + 46)
676 		 */
677 		err = em28xx_i2c_read_block(dev, bus, mc_start + 46, 1, 2,
678 					    data);
679 		if (err != 2) {
680 			em28xx_errdev("failed to read hardware configuration data from eeprom (err=%d)\n",
681 				      err);
682 			goto error;
683 		}
684 
685 		/* Calculate hardware config dataset start address */
686 		hwconf_offset = mc_start + data[0] + (data[1] << 8);
687 
688 		/* Read hardware config dataset */
689 		/*
690 		 * NOTE: the microcode copy can be multiple pages long, but
691 		 * we assume the hardware config dataset is the same as in
692 		 * the old eeprom and not longer than 256 bytes.
693 		 * tveeprom is currently also limited to 256 bytes.
694 		 */
695 		err = em28xx_i2c_read_block(dev, bus, hwconf_offset, 1, len,
696 					    data);
697 		if (err != len) {
698 			em28xx_errdev("failed to read hardware configuration data from eeprom (err=%d)\n",
699 				      err);
700 			goto error;
701 		}
702 
703 		/* Verify hardware config dataset */
704 		/* NOTE: not all devices provide this type of dataset */
705 		if (data[0] != 0x1a || data[1] != 0xeb ||
706 		    data[2] != 0x67 || data[3] != 0x95) {
707 			em28xx_info("\tno hardware configuration dataset found in eeprom\n");
708 			kfree(data);
709 			return 0;
710 		}
711 
712 		/* TODO: decrypt eeprom data for camera bridges (em25xx, em276x+) */
713 
714 	} else if (!dev->eeprom_addrwidth_16bit &&
715 		   data[0] == 0x1a && data[1] == 0xeb &&
716 		   data[2] == 0x67 && data[3] == 0x95) {
717 		dev->hash = em28xx_hash_mem(data, len, 32);
718 		em28xx_info("EEPROM ID = %02x %02x %02x %02x, EEPROM hash = 0x%08lx\n",
719 			    data[0], data[1], data[2], data[3], dev->hash);
720 		em28xx_info("EEPROM info:\n");
721 	} else {
722 		em28xx_info("unknown eeprom format or eeprom corrupted !\n");
723 		err = -ENODEV;
724 		goto error;
725 	}
726 
727 	*eedata = data;
728 	*eedata_len = len;
729 	dev_config = (void *)*eedata;
730 
731 	switch (le16_to_cpu(dev_config->chip_conf) >> 4 & 0x3) {
732 	case 0:
733 		em28xx_info("\tNo audio on board.\n");
734 		break;
735 	case 1:
736 		em28xx_info("\tAC97 audio (5 sample rates)\n");
737 		break;
738 	case 2:
739 		em28xx_info("\tI2S audio, sample rate=32k\n");
740 		break;
741 	case 3:
742 		em28xx_info("\tI2S audio, 3 sample rates\n");
743 		break;
744 	}
745 
746 	if (le16_to_cpu(dev_config->chip_conf) & 1 << 3)
747 		em28xx_info("\tUSB Remote wakeup capable\n");
748 
749 	if (le16_to_cpu(dev_config->chip_conf) & 1 << 2)
750 		em28xx_info("\tUSB Self power capable\n");
751 
752 	switch (le16_to_cpu(dev_config->chip_conf) & 0x3) {
753 	case 0:
754 		em28xx_info("\t500mA max power\n");
755 		break;
756 	case 1:
757 		em28xx_info("\t400mA max power\n");
758 		break;
759 	case 2:
760 		em28xx_info("\t300mA max power\n");
761 		break;
762 	case 3:
763 		em28xx_info("\t200mA max power\n");
764 		break;
765 	}
766 	em28xx_info("\tTable at offset 0x%02x, strings=0x%04x, 0x%04x, 0x%04x\n",
767 		    dev_config->string_idx_table,
768 		    le16_to_cpu(dev_config->string1),
769 		    le16_to_cpu(dev_config->string2),
770 		    le16_to_cpu(dev_config->string3));
771 
772 	return 0;
773 
774 error:
775 	kfree(data);
776 	return err;
777 }
778 
779 /* ----------------------------------------------------------- */
780 
781 /*
782  * functionality()
783  */
784 static u32 functionality(struct i2c_adapter *i2c_adap)
785 {
786 	struct em28xx_i2c_bus *i2c_bus = i2c_adap->algo_data;
787 
788 	if ((i2c_bus->algo_type == EM28XX_I2C_ALGO_EM28XX) ||
789 	    (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM25XX_BUS_B)) {
790 		return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
791 	} else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM2800)  {
792 		return (I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL) &
793 			~I2C_FUNC_SMBUS_WRITE_BLOCK_DATA;
794 	}
795 
796 	WARN(1, "Unknown i2c bus algorithm.\n");
797 	return 0;
798 }
799 
800 static struct i2c_algorithm em28xx_algo = {
801 	.master_xfer   = em28xx_i2c_xfer,
802 	.functionality = functionality,
803 };
804 
805 static struct i2c_adapter em28xx_adap_template = {
806 	.owner = THIS_MODULE,
807 	.name = "em28xx",
808 	.algo = &em28xx_algo,
809 };
810 
811 static struct i2c_client em28xx_client_template = {
812 	.name = "em28xx internal",
813 };
814 
815 /* ----------------------------------------------------------- */
816 
817 /*
818  * i2c_devs
819  * incomplete list of known devices
820  */
821 static char *i2c_devs[128] = {
822 	[0x3e >> 1] = "remote IR sensor",
823 	[0x4a >> 1] = "saa7113h",
824 	[0x52 >> 1] = "drxk",
825 	[0x60 >> 1] = "remote IR sensor",
826 	[0x8e >> 1] = "remote IR sensor",
827 	[0x86 >> 1] = "tda9887",
828 	[0x80 >> 1] = "msp34xx",
829 	[0x88 >> 1] = "msp34xx",
830 	[0xa0 >> 1] = "eeprom",
831 	[0xb0 >> 1] = "tda9874",
832 	[0xb8 >> 1] = "tvp5150a",
833 	[0xba >> 1] = "webcam sensor or tvp5150a",
834 	[0xc0 >> 1] = "tuner (analog)",
835 	[0xc2 >> 1] = "tuner (analog)",
836 	[0xc4 >> 1] = "tuner (analog)",
837 	[0xc6 >> 1] = "tuner (analog)",
838 };
839 
840 /*
841  * do_i2c_scan()
842  * check i2c address range for devices
843  */
844 void em28xx_do_i2c_scan(struct em28xx *dev, unsigned bus)
845 {
846 	u8 i2c_devicelist[128];
847 	unsigned char buf;
848 	int i, rc;
849 
850 	memset(i2c_devicelist, 0, ARRAY_SIZE(i2c_devicelist));
851 
852 	for (i = 0; i < ARRAY_SIZE(i2c_devs); i++) {
853 		dev->i2c_client[bus].addr = i;
854 		rc = i2c_master_recv(&dev->i2c_client[bus], &buf, 0);
855 		if (rc < 0)
856 			continue;
857 		i2c_devicelist[i] = i;
858 		em28xx_info("found i2c device @ 0x%x on bus %d [%s]\n",
859 			    i << 1, bus, i2c_devs[i] ? i2c_devs[i] : "???");
860 	}
861 
862 	if (bus == dev->def_i2c_bus)
863 		dev->i2c_hash = em28xx_hash_mem(i2c_devicelist,
864 						ARRAY_SIZE(i2c_devicelist), 32);
865 }
866 
867 /*
868  * em28xx_i2c_register()
869  * register i2c bus
870  */
871 int em28xx_i2c_register(struct em28xx *dev, unsigned bus,
872 			enum em28xx_i2c_algo_type algo_type)
873 {
874 	int retval;
875 
876 	BUG_ON(!dev->em28xx_write_regs || !dev->em28xx_read_reg);
877 	BUG_ON(!dev->em28xx_write_regs_req || !dev->em28xx_read_reg_req);
878 
879 	if (bus >= NUM_I2C_BUSES)
880 		return -ENODEV;
881 
882 	dev->i2c_adap[bus] = em28xx_adap_template;
883 	dev->i2c_adap[bus].dev.parent = &dev->udev->dev;
884 	strcpy(dev->i2c_adap[bus].name, dev->name);
885 
886 	dev->i2c_bus[bus].bus = bus;
887 	dev->i2c_bus[bus].algo_type = algo_type;
888 	dev->i2c_bus[bus].dev = dev;
889 	dev->i2c_adap[bus].algo_data = &dev->i2c_bus[bus];
890 	i2c_set_adapdata(&dev->i2c_adap[bus], &dev->v4l2_dev);
891 
892 	retval = i2c_add_adapter(&dev->i2c_adap[bus]);
893 	if (retval < 0) {
894 		em28xx_errdev("%s: i2c_add_adapter failed! retval [%d]\n",
895 			__func__, retval);
896 		return retval;
897 	}
898 
899 	dev->i2c_client[bus] = em28xx_client_template;
900 	dev->i2c_client[bus].adapter = &dev->i2c_adap[bus];
901 
902 	/* Up to now, all eeproms are at bus 0 */
903 	if (!bus) {
904 		retval = em28xx_i2c_eeprom(dev, bus, &dev->eedata, &dev->eedata_len);
905 		if ((retval < 0) && (retval != -ENODEV)) {
906 			em28xx_errdev("%s: em28xx_i2_eeprom failed! retval [%d]\n",
907 				__func__, retval);
908 
909 			return retval;
910 		}
911 	}
912 
913 	if (i2c_scan)
914 		em28xx_do_i2c_scan(dev, bus);
915 
916 	return 0;
917 }
918 
919 /*
920  * em28xx_i2c_unregister()
921  * unregister i2c_bus
922  */
923 int em28xx_i2c_unregister(struct em28xx *dev, unsigned bus)
924 {
925 	if (bus >= NUM_I2C_BUSES)
926 		return -ENODEV;
927 
928 	i2c_del_adapter(&dev->i2c_adap[bus]);
929 	return 0;
930 }
931