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(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(5000, 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(5000, 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, 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(5000, 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, 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, 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, msg.buf, msg.len);
497	else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM2800)
498		rc = em2800_i2c_recv_bytes(dev, addr, msg.buf, msg.len);
499	else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM25XX_BUS_B)
500		rc = em25xx_bus_B_recv_bytes(dev, addr, msg.buf, 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, msg.buf, msg.len, stop);
513	else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM2800)
514		rc = em2800_i2c_send_bytes(dev, addr, msg.buf, msg.len);
515	else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM25XX_BUS_B)
516		rc = em25xx_bus_B_send_bytes(dev, addr, msg.buf, 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(&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, 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, msgs[i]);
570		} else {
571			/* write bytes */
572			rc = i2c_send_bytes(i2c_bus, msgs[i], 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(&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(&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(&dev->i2c_client[bus],
645			      buf + !addr_w16, 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(&dev->i2c_client[bus], data, 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(&dev->i2c_client[bus], &buf, 0);
692	if (err < 0) {
693		dev_info(&dev->intf->dev, "board has no eeprom\n");
694		return -ENODEV;
695	}
696
697	data = kzalloc(len, GFP_KERNEL);
698	if (!data)
699		return -ENOMEM;
700
701	/* Read EEPROM content */
702	err = em28xx_i2c_read_block(dev, bus, 0x0000,
703				    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, "em28xx eeprom ", DUMP_PREFIX_OFFSET,
714			       16, 1, data, len, 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(data, len, 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, mc_start + 46, 1, 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, hwconf_offset, 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(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(data, len, 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(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(&dev->i2c_client[bus], &buf, 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(i2c_devicelist,
961						sizeof(i2c_devicelist), 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(&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					   &dev->eedata, &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(&dev->i2c_adap[bus]);
1028	return 0;
1029}
1030