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// This program is free software; you can redistribute it and/or modify
12// it under the terms of the GNU General Public License as published by
13// the Free Software Foundation; either version 2 of the License, or
14// (at your option) any later version.
15//
16// This program is distributed in the hope that it will be useful,
17// but WITHOUT ANY WARRANTY; without even the implied warranty of
18// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19// GNU General Public License for more details.
20
21#include "em28xx.h"
22
23#include <linux/module.h>
24#include <linux/kernel.h>
25#include <linux/usb.h>
26#include <linux/i2c.h>
27#include <linux/jiffies.h>
28
29#include "tuner-xc2028.h"
30#include <media/v4l2-common.h>
31#include <media/tuner.h>
32
33/* ----------------------------------------------------------- */
34
35static unsigned int i2c_scan;
36module_param(i2c_scan, int, 0444);
37MODULE_PARM_DESC(i2c_scan, "scan i2c bus at insmod time");
38
39static unsigned int i2c_debug;
40module_param(i2c_debug, int, 0644);
41MODULE_PARM_DESC(i2c_debug, "i2c debug message level (1: normal debug, 2: show I2C transfers)");
42
43#define dprintk(level, fmt, arg...) do {				\
44	if (i2c_debug > level)						\
45		dev_printk(KERN_DEBUG, &dev->intf->dev,			\
46			   "i2c: %s: " fmt, __func__, ## arg);		\
47} while (0)
48
49/*
50 * Time in msecs to wait for i2c xfers to finish.
51 * 35ms is the maximum time a SMBUS device could wait when
52 * clock stretching is used. As the transfer itself will take
53 * some time to happen, set it to 35 ms.
54 *
55 * Ok, I2C doesn't specify any limit. So, eventually, we may need
56 * to increase this timeout.
57 */
58#define EM28XX_I2C_XFER_TIMEOUT         35 /* ms */
59
60static int em28xx_i2c_timeout(struct em28xx *dev)
61{
62	int time = EM28XX_I2C_XFER_TIMEOUT;
63
64	switch (dev->i2c_speed & 0x03) {
65	case EM28XX_I2C_FREQ_25_KHZ:
66		time += 4;		/* Assume 4 ms for transfers */
67		break;
68	case EM28XX_I2C_FREQ_100_KHZ:
69	case EM28XX_I2C_FREQ_400_KHZ:
70		time += 1;		/* Assume 1 ms for transfers */
71		break;
72	default: /* EM28XX_I2C_FREQ_1_5_MHZ */
73		break;
74	}
75
76	return msecs_to_jiffies(time);
77}
78
79/*
80 * em2800_i2c_send_bytes()
81 * send up to 4 bytes to the em2800 i2c device
82 */
83static int em2800_i2c_send_bytes(struct em28xx *dev, u8 addr, u8 *buf, u16 len)
84{
85	unsigned long timeout = jiffies + em28xx_i2c_timeout(dev);
86	int ret;
87	u8 b2[6];
88
89	if (len < 1 || len > 4)
90		return -EOPNOTSUPP;
91
92	b2[5] = 0x80 + len - 1;
93	b2[4] = addr;
94	b2[3] = buf[0];
95	if (len > 1)
96		b2[2] = buf[1];
97	if (len > 2)
98		b2[1] = buf[2];
99	if (len > 3)
100		b2[0] = buf[3];
101
102	/* trigger write */
103	ret = dev->em28xx_write_regs(dev, 4 - len, &b2[4 - len], 2 + len);
104	if (ret != 2 + len) {
105		dev_warn(&dev->intf->dev,
106			 "failed to trigger write to i2c address 0x%x (error=%i)\n",
107			    addr, ret);
108		return (ret < 0) ? ret : -EIO;
109	}
110	/* wait for completion */
111	while (time_is_after_jiffies(timeout)) {
112		ret = dev->em28xx_read_reg(dev, 0x05);
113		if (ret == 0x80 + len - 1)
114			return len;
115		if (ret == 0x94 + len - 1) {
116			dprintk(1, "R05 returned 0x%02x: I2C ACK error\n", ret);
117			return -ENXIO;
118		}
119		if (ret < 0) {
120			dev_warn(&dev->intf->dev,
121				 "failed to get i2c transfer status from bridge register (error=%i)\n",
122				ret);
123			return ret;
124		}
125		usleep_range(5000, 6000);
126	}
127	dprintk(0, "write to i2c device at 0x%x timed out\n", addr);
128	return -ETIMEDOUT;
129}
130
131/*
132 * em2800_i2c_recv_bytes()
133 * read up to 4 bytes from the em2800 i2c device
134 */
135static int em2800_i2c_recv_bytes(struct em28xx *dev, u8 addr, u8 *buf, u16 len)
136{
137	unsigned long timeout = jiffies + em28xx_i2c_timeout(dev);
138	u8 buf2[4];
139	int ret;
140	int i;
141
142	if (len < 1 || len > 4)
143		return -EOPNOTSUPP;
144
145	/* trigger read */
146	buf2[1] = 0x84 + len - 1;
147	buf2[0] = addr;
148	ret = dev->em28xx_write_regs(dev, 0x04, buf2, 2);
149	if (ret != 2) {
150		dev_warn(&dev->intf->dev,
151			 "failed to trigger read from i2c address 0x%x (error=%i)\n",
152			 addr, ret);
153		return (ret < 0) ? ret : -EIO;
154	}
155
156	/* wait for completion */
157	while (time_is_after_jiffies(timeout)) {
158		ret = dev->em28xx_read_reg(dev, 0x05);
159		if (ret == 0x84 + len - 1)
160			break;
161		if (ret == 0x94 + len - 1) {
162			dprintk(1, "R05 returned 0x%02x: I2C ACK error\n",
163				ret);
164			return -ENXIO;
165		}
166		if (ret < 0) {
167			dev_warn(&dev->intf->dev,
168				 "failed to get i2c transfer status from bridge register (error=%i)\n",
169				 ret);
170			return ret;
171		}
172		usleep_range(5000, 6000);
173	}
174	if (ret != 0x84 + len - 1)
175		dprintk(0, "read from i2c device at 0x%x timed out\n", addr);
176
177	/* get the received message */
178	ret = dev->em28xx_read_reg_req_len(dev, 0x00, 4 - len, buf2, len);
179	if (ret != len) {
180		dev_warn(&dev->intf->dev,
181			 "reading from i2c device at 0x%x failed: couldn't get the received message from the bridge (error=%i)\n",
182			 addr, ret);
183		return (ret < 0) ? ret : -EIO;
184	}
185	for (i = 0; i < len; i++)
186		buf[i] = buf2[len - 1 - i];
187
188	return ret;
189}
190
191/*
192 * em2800_i2c_check_for_device()
193 * check if there is an i2c device at the supplied address
194 */
195static int em2800_i2c_check_for_device(struct em28xx *dev, u8 addr)
196{
197	u8 buf;
198	int ret;
199
200	ret = em2800_i2c_recv_bytes(dev, addr, &buf, 1);
201	if (ret == 1)
202		return 0;
203	return (ret < 0) ? ret : -EIO;
204}
205
206/*
207 * em28xx_i2c_send_bytes()
208 */
209static int em28xx_i2c_send_bytes(struct em28xx *dev, u16 addr, u8 *buf,
210				 u16 len, int stop)
211{
212	unsigned long timeout = jiffies + em28xx_i2c_timeout(dev);
213	int ret;
214
215	if (len < 1 || len > 64)
216		return -EOPNOTSUPP;
217	/*
218	 * NOTE: limited by the USB ctrl message constraints
219	 * Zero length reads always succeed, even if no device is connected
220	 */
221
222	/* Write to i2c device */
223	ret = dev->em28xx_write_regs_req(dev, stop ? 2 : 3, addr, buf, len);
224	if (ret != len) {
225		if (ret < 0) {
226			dev_warn(&dev->intf->dev,
227				 "writing to i2c device at 0x%x failed (error=%i)\n",
228				 addr, ret);
229			return ret;
230		}
231		dev_warn(&dev->intf->dev,
232			 "%i bytes write to i2c device at 0x%x requested, but %i bytes written\n",
233				len, addr, ret);
234		return -EIO;
235	}
236
237	/* wait for completion */
238	while (time_is_after_jiffies(timeout)) {
239		ret = dev->em28xx_read_reg(dev, 0x05);
240		if (ret == 0) /* success */
241			return len;
242		if (ret == 0x10) {
243			dprintk(1, "I2C ACK error on writing to addr 0x%02x\n",
244				addr);
245			return -ENXIO;
246		}
247		if (ret < 0) {
248			dev_warn(&dev->intf->dev,
249				 "failed to get i2c transfer status from bridge register (error=%i)\n",
250				 ret);
251			return ret;
252		}
253		usleep_range(5000, 6000);
254		/*
255		 * NOTE: do we really have to wait for success ?
256		 * Never seen anything else than 0x00 or 0x10
257		 * (even with high payload) ...
258		 */
259	}
260
261	if (ret == 0x02 || ret == 0x04) {
262		/* NOTE: these errors seem to be related to clock stretching */
263		dprintk(0,
264			"write to i2c device at 0x%x timed out (status=%i)\n",
265			addr, ret);
266		return -ETIMEDOUT;
267	}
268
269	dev_warn(&dev->intf->dev,
270		 "write to i2c device at 0x%x failed with unknown error (status=%i)\n",
271		 addr, ret);
272	return -EIO;
273}
274
275/*
276 * em28xx_i2c_recv_bytes()
277 * read a byte from the i2c device
278 */
279static int em28xx_i2c_recv_bytes(struct em28xx *dev, u16 addr, u8 *buf, u16 len)
280{
281	int ret;
282
283	if (len < 1 || len > 64)
284		return -EOPNOTSUPP;
285	/*
286	 * NOTE: limited by the USB ctrl message constraints
287	 * Zero length reads always succeed, even if no device is connected
288	 */
289
290	/* Read data from i2c device */
291	ret = dev->em28xx_read_reg_req_len(dev, 2, addr, buf, len);
292	if (ret < 0) {
293		dev_warn(&dev->intf->dev,
294			 "reading from i2c device at 0x%x failed (error=%i)\n",
295			 addr, ret);
296		return ret;
297	}
298	/*
299	 * NOTE: some devices with two i2c buses have the bad habit to return 0
300	 * bytes if we are on bus B AND there was no write attempt to the
301	 * specified slave address before AND no device is present at the
302	 * requested slave address.
303	 * Anyway, the next check will fail with -ENXIO in this case, so avoid
304	 * spamming the system log on device probing and do nothing here.
305	 */
306
307	/* Check success of the i2c operation */
308	ret = dev->em28xx_read_reg(dev, 0x05);
309	if (ret == 0) /* success */
310		return len;
311	if (ret < 0) {
312		dev_warn(&dev->intf->dev,
313			 "failed to get i2c transfer status from bridge register (error=%i)\n",
314			 ret);
315		return ret;
316	}
317	if (ret == 0x10) {
318		dprintk(1, "I2C ACK error on writing to addr 0x%02x\n",
319			addr);
320		return -ENXIO;
321	}
322
323	if (ret == 0x02 || ret == 0x04) {
324		/* NOTE: these errors seem to be related to clock stretching */
325		dprintk(0,
326			"write to i2c device at 0x%x timed out (status=%i)\n",
327			addr, ret);
328		return -ETIMEDOUT;
329	}
330
331	dev_warn(&dev->intf->dev,
332		 "write to i2c device at 0x%x failed with unknown error (status=%i)\n",
333		 addr, ret);
334	return -EIO;
335}
336
337/*
338 * em28xx_i2c_check_for_device()
339 * check if there is a i2c_device at the supplied address
340 */
341static int em28xx_i2c_check_for_device(struct em28xx *dev, u16 addr)
342{
343	int ret;
344	u8 buf;
345
346	ret = em28xx_i2c_recv_bytes(dev, addr, &buf, 1);
347	if (ret == 1)
348		return 0;
349	return (ret < 0) ? ret : -EIO;
350}
351
352/*
353 * em25xx_bus_B_send_bytes
354 * write bytes to the i2c device
355 */
356static int em25xx_bus_B_send_bytes(struct em28xx *dev, u16 addr, u8 *buf,
357				   u16 len)
358{
359	int ret;
360
361	if (len < 1 || len > 64)
362		return -EOPNOTSUPP;
363	/*
364	 * NOTE: limited by the USB ctrl message constraints
365	 * Zero length reads always succeed, even if no device is connected
366	 */
367
368	/* Set register and write value */
369	ret = dev->em28xx_write_regs_req(dev, 0x06, addr, buf, len);
370	if (ret != len) {
371		if (ret < 0) {
372			dev_warn(&dev->intf->dev,
373				 "writing to i2c device at 0x%x failed (error=%i)\n",
374				 addr, ret);
375			return ret;
376		}
377
378		dev_warn(&dev->intf->dev,
379			 "%i bytes write to i2c device at 0x%x requested, but %i bytes written\n",
380			 len, addr, ret);
381		return -EIO;
382	}
383	/* Check success */
384	ret = dev->em28xx_read_reg_req(dev, 0x08, 0x0000);
385	/*
386	 * NOTE: the only error we've seen so far is
387	 * 0x01 when the slave device is not present
388	 */
389	if (!ret)
390		return len;
391
392	if (ret > 0) {
393		dprintk(1, "Bus B R08 returned 0x%02x: I2C ACK error\n", ret);
394		return -ENXIO;
395	}
396
397	return ret;
398	/*
399	 * NOTE: With chip types (other chip IDs) which actually don't support
400	 * this operation, it seems to succeed ALWAYS ! (even if there is no
401	 * slave device or even no second i2c bus provided)
402	 */
403}
404
405/*
406 * em25xx_bus_B_recv_bytes
407 * read bytes from the i2c device
408 */
409static int em25xx_bus_B_recv_bytes(struct em28xx *dev, u16 addr, u8 *buf,
410				   u16 len)
411{
412	int ret;
413
414	if (len < 1 || len > 64)
415		return -EOPNOTSUPP;
416	/*
417	 * NOTE: limited by the USB ctrl message constraints
418	 * Zero length reads always succeed, even if no device is connected
419	 */
420
421	/* Read value */
422	ret = dev->em28xx_read_reg_req_len(dev, 0x06, addr, buf, len);
423	if (ret < 0) {
424		dev_warn(&dev->intf->dev,
425			 "reading from i2c device at 0x%x failed (error=%i)\n",
426			 addr, ret);
427		return ret;
428	}
429	/*
430	 * NOTE: some devices with two i2c buses have the bad habit to return 0
431	 * bytes if we are on bus B AND there was no write attempt to the
432	 * specified slave address before AND no device is present at the
433	 * requested slave address.
434	 * Anyway, the next check will fail with -ENXIO in this case, so avoid
435	 * spamming the system log on device probing and do nothing here.
436	 */
437
438	/* Check success */
439	ret = dev->em28xx_read_reg_req(dev, 0x08, 0x0000);
440	/*
441	 * NOTE: the only error we've seen so far is
442	 * 0x01 when the slave device is not present
443	 */
444	if (!ret)
445		return len;
446
447	if (ret > 0) {
448		dprintk(1, "Bus B R08 returned 0x%02x: I2C ACK error\n", ret);
449		return -ENXIO;
450	}
451
452	return ret;
453	/*
454	 * NOTE: With chip types (other chip IDs) which actually don't support
455	 * this operation, it seems to succeed ALWAYS ! (even if there is no
456	 * slave device or even no second i2c bus provided)
457	 */
458}
459
460/*
461 * em25xx_bus_B_check_for_device()
462 * check if there is a i2c device at the supplied address
463 */
464static int em25xx_bus_B_check_for_device(struct em28xx *dev, u16 addr)
465{
466	u8 buf;
467	int ret;
468
469	ret = em25xx_bus_B_recv_bytes(dev, addr, &buf, 1);
470	if (ret < 0)
471		return ret;
472
473	return 0;
474	/*
475	 * NOTE: With chips which do not support this operation,
476	 * it seems to succeed ALWAYS ! (even if no device connected)
477	 */
478}
479
480static inline int i2c_check_for_device(struct em28xx_i2c_bus *i2c_bus, u16 addr)
481{
482	struct em28xx *dev = i2c_bus->dev;
483	int rc = -EOPNOTSUPP;
484
485	if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM28XX)
486		rc = em28xx_i2c_check_for_device(dev, addr);
487	else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM2800)
488		rc = em2800_i2c_check_for_device(dev, addr);
489	else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM25XX_BUS_B)
490		rc = em25xx_bus_B_check_for_device(dev, addr);
491	return rc;
492}
493
494static inline int i2c_recv_bytes(struct em28xx_i2c_bus *i2c_bus,
495				 struct i2c_msg msg)
496{
497	struct em28xx *dev = i2c_bus->dev;
498	u16 addr = msg.addr << 1;
499	int rc = -EOPNOTSUPP;
500
501	if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM28XX)
502		rc = em28xx_i2c_recv_bytes(dev, addr, msg.buf, msg.len);
503	else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM2800)
504		rc = em2800_i2c_recv_bytes(dev, addr, msg.buf, msg.len);
505	else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM25XX_BUS_B)
506		rc = em25xx_bus_B_recv_bytes(dev, addr, msg.buf, msg.len);
507	return rc;
508}
509
510static inline int i2c_send_bytes(struct em28xx_i2c_bus *i2c_bus,
511				 struct i2c_msg msg, int stop)
512{
513	struct em28xx *dev = i2c_bus->dev;
514	u16 addr = msg.addr << 1;
515	int rc = -EOPNOTSUPP;
516
517	if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM28XX)
518		rc = em28xx_i2c_send_bytes(dev, addr, msg.buf, msg.len, stop);
519	else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM2800)
520		rc = em2800_i2c_send_bytes(dev, addr, msg.buf, msg.len);
521	else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM25XX_BUS_B)
522		rc = em25xx_bus_B_send_bytes(dev, addr, msg.buf, msg.len);
523	return rc;
524}
525
526/*
527 * em28xx_i2c_xfer()
528 * the main i2c transfer function
529 */
530static int em28xx_i2c_xfer(struct i2c_adapter *i2c_adap,
531			   struct i2c_msg msgs[], int num)
532{
533	struct em28xx_i2c_bus *i2c_bus = i2c_adap->algo_data;
534	struct em28xx *dev = i2c_bus->dev;
535	unsigned int bus = i2c_bus->bus;
536	int addr, rc, i;
537	u8 reg;
538
539	/*
540	 * prevent i2c xfer attempts after device is disconnected
541	 * some fe's try to do i2c writes/reads from their release
542	 * interfaces when called in disconnect path
543	 */
544	if (dev->disconnected)
545		return -ENODEV;
546
547	if (!rt_mutex_trylock(&dev->i2c_bus_lock))
548		return -EAGAIN;
549
550	/* Switch I2C bus if needed */
551	if (bus != dev->cur_i2c_bus &&
552	    i2c_bus->algo_type == EM28XX_I2C_ALGO_EM28XX) {
553		if (bus == 1)
554			reg = EM2874_I2C_SECONDARY_BUS_SELECT;
555		else
556			reg = 0;
557		em28xx_write_reg_bits(dev, EM28XX_R06_I2C_CLK, reg,
558				      EM2874_I2C_SECONDARY_BUS_SELECT);
559		dev->cur_i2c_bus = bus;
560	}
561
562	for (i = 0; i < num; i++) {
563		addr = msgs[i].addr << 1;
564		if (!msgs[i].len) {
565			/*
566			 * no len: check only for device presence
567			 * This code is only called during device probe.
568			 */
569			rc = i2c_check_for_device(i2c_bus, addr);
570
571			if (rc == -ENXIO)
572				rc = -ENODEV;
573		} else if (msgs[i].flags & I2C_M_RD) {
574			/* read bytes */
575			rc = i2c_recv_bytes(i2c_bus, msgs[i]);
576		} else {
577			/* write bytes */
578			rc = i2c_send_bytes(i2c_bus, msgs[i], i == num - 1);
579		}
580
581		if (rc < 0)
582			goto error;
583
584		dprintk(2, "%s %s addr=%02x len=%d: %*ph\n",
585			(msgs[i].flags & I2C_M_RD) ? "read" : "write",
586			i == num - 1 ? "stop" : "nonstop",
587			addr, msgs[i].len,
588			msgs[i].len, msgs[i].buf);
589	}
590
591	rt_mutex_unlock(&dev->i2c_bus_lock);
592	return num;
593
594error:
595	dprintk(2, "%s %s addr=%02x len=%d: %sERROR: %i\n",
596		(msgs[i].flags & I2C_M_RD) ? "read" : "write",
597		i == num - 1 ? "stop" : "nonstop",
598		addr, msgs[i].len,
599		(rc == -ENODEV) ? "no device " : "",
600		rc);
601
602	rt_mutex_unlock(&dev->i2c_bus_lock);
603	return rc;
604}
605
606/*
607 * based on linux/sunrpc/svcauth.h and linux/hash.h
608 * The original hash function returns a different value, if arch is x86_64
609 * or i386.
610 */
611static inline unsigned long em28xx_hash_mem(char *buf, int length, int bits)
612{
613	unsigned long hash = 0;
614	unsigned long l = 0;
615	int len = 0;
616	unsigned char c;
617
618	do {
619		if (len == length) {
620			c = (char)len;
621			len = -1;
622		} else {
623			c = *buf++;
624		}
625		l = (l << 8) | c;
626		len++;
627		if ((len & (32 / 8 - 1)) == 0)
628			hash = ((hash ^ l) * 0x9e370001UL);
629	} while (len);
630
631	return (hash >> (32 - bits)) & 0xffffffffUL;
632}
633
634/*
635 * Helper function to read data blocks from i2c clients with 8 or 16 bit
636 * address width, 8 bit register width and auto incrementation been activated
637 */
638static int em28xx_i2c_read_block(struct em28xx *dev, unsigned int bus, u16 addr,
639				 bool addr_w16, u16 len, u8 *data)
640{
641	int remain = len, rsize, rsize_max, ret;
642	u8 buf[2];
643
644	/* Sanity check */
645	if (addr + remain > (addr_w16 * 0xff00 + 0xff + 1))
646		return -EINVAL;
647	/* Select address */
648	buf[0] = addr >> 8;
649	buf[1] = addr & 0xff;
650	ret = i2c_master_send(&dev->i2c_client[bus],
651			      buf + !addr_w16, 1 + addr_w16);
652	if (ret < 0)
653		return ret;
654	/* Read data */
655	if (dev->board.is_em2800)
656		rsize_max = 4;
657	else
658		rsize_max = 64;
659	while (remain > 0) {
660		if (remain > rsize_max)
661			rsize = rsize_max;
662		else
663			rsize = remain;
664
665		ret = i2c_master_recv(&dev->i2c_client[bus], data, rsize);
666		if (ret < 0)
667			return ret;
668
669		remain -= rsize;
670		data += rsize;
671	}
672
673	return len;
674}
675
676static int em28xx_i2c_eeprom(struct em28xx *dev, unsigned int bus,
677			     u8 **eedata, u16 *eedata_len)
678{
679	const u16 len = 256;
680	/*
681	 * FIXME common length/size for bytes to read, to display, hash
682	 * calculation and returned device dataset. Simplifies the code a lot,
683	 * but we might have to deal with multiple sizes in the future !
684	 */
685	int err;
686	struct em28xx_eeprom *dev_config;
687	u8 buf, *data;
688
689	*eedata = NULL;
690	*eedata_len = 0;
691
692	/* EEPROM is always on i2c bus 0 on all known devices. */
693
694	dev->i2c_client[bus].addr = 0xa0 >> 1;
695
696	/* Check if board has eeprom */
697	err = i2c_master_recv(&dev->i2c_client[bus], &buf, 0);
698	if (err < 0) {
699		dev_info(&dev->intf->dev, "board has no eeprom\n");
700		return -ENODEV;
701	}
702
703	data = kzalloc(len, GFP_KERNEL);
704	if (!data)
705		return -ENOMEM;
706
707	/* Read EEPROM content */
708	err = em28xx_i2c_read_block(dev, bus, 0x0000,
709				    dev->eeprom_addrwidth_16bit,
710				    len, data);
711	if (err != len) {
712		dev_err(&dev->intf->dev,
713			"failed to read eeprom (err=%d)\n", err);
714		goto error;
715	}
716
717	if (i2c_debug) {
718		/* Display eeprom content */
719		print_hex_dump(KERN_DEBUG, "em28xx eeprom ", DUMP_PREFIX_OFFSET,
720			       16, 1, data, len, true);
721
722		if (dev->eeprom_addrwidth_16bit)
723			dev_info(&dev->intf->dev,
724				 "eeprom %06x: ... (skipped)\n", 256);
725	}
726
727	if (dev->eeprom_addrwidth_16bit &&
728	    data[0] == 0x26 && data[3] == 0x00) {
729		/* new eeprom format; size 4-64kb */
730		u16 mc_start;
731		u16 hwconf_offset;
732
733		dev->hash = em28xx_hash_mem(data, len, 32);
734		mc_start = (data[1] << 8) + 4;	/* usually 0x0004 */
735
736		dev_info(&dev->intf->dev,
737			 "EEPROM ID = %4ph, EEPROM hash = 0x%08lx\n",
738			 data, dev->hash);
739		dev_info(&dev->intf->dev,
740			 "EEPROM info:\n");
741		dev_info(&dev->intf->dev,
742			 "\tmicrocode start address = 0x%04x, boot configuration = 0x%02x\n",
743			 mc_start, data[2]);
744		/*
745		 * boot configuration (address 0x0002):
746		 * [0]   microcode download speed: 1 = 400 kHz; 0 = 100 kHz
747		 * [1]   always selects 12 kb RAM
748		 * [2]   USB device speed: 1 = force Full Speed; 0 = auto detect
749		 * [4]   1 = force fast mode and no suspend for device testing
750		 * [5:7] USB PHY tuning registers; determined by device
751		 *       characterization
752		 */
753
754		/*
755		 * Read hardware config dataset offset from address
756		 * (microcode start + 46)
757		 */
758		err = em28xx_i2c_read_block(dev, bus, mc_start + 46, 1, 2,
759					    data);
760		if (err != 2) {
761			dev_err(&dev->intf->dev,
762				"failed to read hardware configuration data from eeprom (err=%d)\n",
763				err);
764			goto error;
765		}
766
767		/* Calculate hardware config dataset start address */
768		hwconf_offset = mc_start + data[0] + (data[1] << 8);
769
770		/* Read hardware config dataset */
771		/*
772		 * NOTE: the microcode copy can be multiple pages long, but
773		 * we assume the hardware config dataset is the same as in
774		 * the old eeprom and not longer than 256 bytes.
775		 * tveeprom is currently also limited to 256 bytes.
776		 */
777		err = em28xx_i2c_read_block(dev, bus, hwconf_offset, 1, len,
778					    data);
779		if (err != len) {
780			dev_err(&dev->intf->dev,
781				"failed to read hardware configuration data from eeprom (err=%d)\n",
782				err);
783			goto error;
784		}
785
786		/* Verify hardware config dataset */
787		/* NOTE: not all devices provide this type of dataset */
788		if (data[0] != 0x1a || data[1] != 0xeb ||
789		    data[2] != 0x67 || data[3] != 0x95) {
790			dev_info(&dev->intf->dev,
791				 "\tno hardware configuration dataset found in eeprom\n");
792			kfree(data);
793			return 0;
794		}
795
796		/*
797		 * TODO: decrypt eeprom data for camera bridges
798		 * (em25xx, em276x+)
799		 */
800
801	} else if (!dev->eeprom_addrwidth_16bit &&
802		   data[0] == 0x1a && data[1] == 0xeb &&
803		   data[2] == 0x67 && data[3] == 0x95) {
804		dev->hash = em28xx_hash_mem(data, len, 32);
805		dev_info(&dev->intf->dev,
806			 "EEPROM ID = %4ph, EEPROM hash = 0x%08lx\n",
807			 data, dev->hash);
808		dev_info(&dev->intf->dev,
809			 "EEPROM info:\n");
810	} else {
811		dev_info(&dev->intf->dev,
812			 "unknown eeprom format or eeprom corrupted !\n");
813		err = -ENODEV;
814		goto error;
815	}
816
817	*eedata = data;
818	*eedata_len = len;
819	dev_config = (void *)*eedata;
820
821	switch (le16_to_cpu(dev_config->chip_conf) >> 4 & 0x3) {
822	case 0:
823		dev_info(&dev->intf->dev, "\tNo audio on board.\n");
824		break;
825	case 1:
826		dev_info(&dev->intf->dev, "\tAC97 audio (5 sample rates)\n");
827		break;
828	case 2:
829		if (dev->chip_id < CHIP_ID_EM2860)
830			dev_info(&dev->intf->dev,
831				 "\tI2S audio, sample rate=32k\n");
832		else
833			dev_info(&dev->intf->dev,
834				 "\tI2S audio, 3 sample rates\n");
835		break;
836	case 3:
837		if (dev->chip_id < CHIP_ID_EM2860)
838			dev_info(&dev->intf->dev,
839				 "\tI2S audio, 3 sample rates\n");
840		else
841			dev_info(&dev->intf->dev,
842				 "\tI2S audio, 5 sample rates\n");
843		break;
844	}
845
846	if (le16_to_cpu(dev_config->chip_conf) & 1 << 3)
847		dev_info(&dev->intf->dev, "\tUSB Remote wakeup capable\n");
848
849	if (le16_to_cpu(dev_config->chip_conf) & 1 << 2)
850		dev_info(&dev->intf->dev, "\tUSB Self power capable\n");
851
852	switch (le16_to_cpu(dev_config->chip_conf) & 0x3) {
853	case 0:
854		dev_info(&dev->intf->dev, "\t500mA max power\n");
855		break;
856	case 1:
857		dev_info(&dev->intf->dev, "\t400mA max power\n");
858		break;
859	case 2:
860		dev_info(&dev->intf->dev, "\t300mA max power\n");
861		break;
862	case 3:
863		dev_info(&dev->intf->dev, "\t200mA max power\n");
864		break;
865	}
866	dev_info(&dev->intf->dev,
867		 "\tTable at offset 0x%02x, strings=0x%04x, 0x%04x, 0x%04x\n",
868		 dev_config->string_idx_table,
869		 le16_to_cpu(dev_config->string1),
870		 le16_to_cpu(dev_config->string2),
871		 le16_to_cpu(dev_config->string3));
872
873	return 0;
874
875error:
876	kfree(data);
877	return err;
878}
879
880/* ----------------------------------------------------------- */
881
882/*
883 * functionality()
884 */
885static u32 functionality(struct i2c_adapter *i2c_adap)
886{
887	struct em28xx_i2c_bus *i2c_bus = i2c_adap->algo_data;
888
889	if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM28XX ||
890	    i2c_bus->algo_type == EM28XX_I2C_ALGO_EM25XX_BUS_B) {
891		return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
892	} else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM2800)  {
893		return (I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL) &
894			~I2C_FUNC_SMBUS_WRITE_BLOCK_DATA;
895	}
896
897	WARN(1, "Unknown i2c bus algorithm.\n");
898	return 0;
899}
900
901static const struct i2c_algorithm em28xx_algo = {
902	.master_xfer   = em28xx_i2c_xfer,
903	.functionality = functionality,
904};
905
906static const struct i2c_adapter em28xx_adap_template = {
907	.owner = THIS_MODULE,
908	.name = "em28xx",
909	.algo = &em28xx_algo,
910};
911
912static const struct i2c_client em28xx_client_template = {
913	.name = "em28xx internal",
914};
915
916/* ----------------------------------------------------------- */
917
918/*
919 * i2c_devs
920 * incomplete list of known devices
921 */
922static char *i2c_devs[128] = {
923	[0x1c >> 1] = "lgdt330x",
924	[0x3e >> 1] = "remote IR sensor",
925	[0x4a >> 1] = "saa7113h",
926	[0x52 >> 1] = "drxk",
927	[0x60 >> 1] = "remote IR sensor",
928	[0x8e >> 1] = "remote IR sensor",
929	[0x86 >> 1] = "tda9887",
930	[0x80 >> 1] = "msp34xx",
931	[0x88 >> 1] = "msp34xx",
932	[0xa0 >> 1] = "eeprom",
933	[0xb0 >> 1] = "tda9874",
934	[0xb8 >> 1] = "tvp5150a",
935	[0xba >> 1] = "webcam sensor or tvp5150a",
936	[0xc0 >> 1] = "tuner (analog)",
937	[0xc2 >> 1] = "tuner (analog)",
938	[0xc4 >> 1] = "tuner (analog)",
939	[0xc6 >> 1] = "tuner (analog)",
940};
941
942/*
943 * do_i2c_scan()
944 * check i2c address range for devices
945 */
946void em28xx_do_i2c_scan(struct em28xx *dev, unsigned int bus)
947{
948	u8 i2c_devicelist[128];
949	unsigned char buf;
950	int i, rc;
951
952	memset(i2c_devicelist, 0, sizeof(i2c_devicelist));
953
954	for (i = 0; i < ARRAY_SIZE(i2c_devs); i++) {
955		dev->i2c_client[bus].addr = i;
956		rc = i2c_master_recv(&dev->i2c_client[bus], &buf, 0);
957		if (rc < 0)
958			continue;
959		i2c_devicelist[i] = i;
960		dev_info(&dev->intf->dev,
961			 "found i2c device @ 0x%x on bus %d [%s]\n",
962			 i << 1, bus, i2c_devs[i] ? i2c_devs[i] : "???");
963	}
964
965	if (bus == dev->def_i2c_bus)
966		dev->i2c_hash = em28xx_hash_mem(i2c_devicelist,
967						sizeof(i2c_devicelist), 32);
968}
969
970/*
971 * em28xx_i2c_register()
972 * register i2c bus
973 */
974int em28xx_i2c_register(struct em28xx *dev, unsigned int bus,
975			enum em28xx_i2c_algo_type algo_type)
976{
977	int retval;
978
979	if (WARN_ON(!dev->em28xx_write_regs || !dev->em28xx_read_reg ||
980		    !dev->em28xx_write_regs_req || !dev->em28xx_read_reg_req))
981		return -ENODEV;
982
983	if (bus >= NUM_I2C_BUSES)
984		return -ENODEV;
985
986	dev->i2c_adap[bus] = em28xx_adap_template;
987	dev->i2c_adap[bus].dev.parent = &dev->intf->dev;
988	strscpy(dev->i2c_adap[bus].name, dev_name(&dev->intf->dev),
989		sizeof(dev->i2c_adap[bus].name));
990
991	dev->i2c_bus[bus].bus = bus;
992	dev->i2c_bus[bus].algo_type = algo_type;
993	dev->i2c_bus[bus].dev = dev;
994	dev->i2c_adap[bus].algo_data = &dev->i2c_bus[bus];
995
996	retval = i2c_add_adapter(&dev->i2c_adap[bus]);
997	if (retval < 0) {
998		dev_err(&dev->intf->dev,
999			"%s: i2c_add_adapter failed! retval [%d]\n",
1000			__func__, retval);
1001		return retval;
1002	}
1003
1004	dev->i2c_client[bus] = em28xx_client_template;
1005	dev->i2c_client[bus].adapter = &dev->i2c_adap[bus];
1006
1007	/* Up to now, all eeproms are at bus 0 */
1008	if (!bus) {
1009		retval = em28xx_i2c_eeprom(dev, bus,
1010					   &dev->eedata, &dev->eedata_len);
1011		if (retval < 0 && retval != -ENODEV) {
1012			dev_err(&dev->intf->dev,
1013				"%s: em28xx_i2_eeprom failed! retval [%d]\n",
1014				__func__, retval);
1015		}
1016	}
1017
1018	if (i2c_scan)
1019		em28xx_do_i2c_scan(dev, bus);
1020
1021	return 0;
1022}
1023
1024/*
1025 * em28xx_i2c_unregister()
1026 * unregister i2c_bus
1027 */
1028int em28xx_i2c_unregister(struct em28xx *dev, unsigned int bus)
1029{
1030	if (bus >= NUM_I2C_BUSES)
1031		return -ENODEV;
1032
1033	i2c_del_adapter(&dev->i2c_adap[bus]);
1034	return 0;
1035}
1036