usbvision-i2c.c revision 39f46adef8e83653b4716369683c134e1413ad30
1/*
2 * usbvision_i2c.c
3 *  i2c algorithm for USB-I2C Bridges
4 *
5 * Copyright (c) 1999-2007 Joerg Heckenbach <joerg@heckenbach-aw.de>
6 *                         Dwaine Garden <dwainegarden@rogers.com>
7 *
8 * This module is part of usbvision driver project.
9 * Updates to driver completed by Dwaine P. Garden
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 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 */
25
26
27#include <linux/kernel.h>
28#include <linux/module.h>
29#include <linux/delay.h>
30#include <linux/slab.h>
31#include <linux/version.h>
32#include <linux/utsname.h>
33#include <linux/init.h>
34#include <asm/uaccess.h>
35#include <linux/ioport.h>
36#include <linux/errno.h>
37#include <linux/usb.h>
38#include <linux/i2c.h>
39#include "usbvision.h"
40
41#define DBG_I2C		1<<0
42
43static int i2c_debug = 0;
44
45module_param (i2c_debug, int, 0644);			// debug_i2c_usb mode of the device driver
46MODULE_PARM_DESC(i2c_debug, "enable debug messages [i2c]");
47
48#define PDEBUG(level, fmt, args...) \
49		if (i2c_debug & (level)) info("[%s:%d] " fmt, __PRETTY_FUNCTION__, __LINE__ , ## args)
50
51static int usbvision_i2c_write(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
52			    short len);
53static int usbvision_i2c_read(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
54			   short len);
55
56static inline int try_write_address(struct i2c_adapter *i2c_adap,
57				    unsigned char addr, int retries)
58{
59	struct usb_usbvision *usbvision;
60	int i, ret = -1;
61	char buf[4];
62
63	usbvision = (struct usb_usbvision *)i2c_get_adapdata(i2c_adap);
64	buf[0] = 0x00;
65	for (i = 0; i <= retries; i++) {
66		ret = (usbvision_i2c_write(usbvision, addr, buf, 1));
67		if (ret == 1)
68			break;	/* success! */
69		udelay(5);
70		if (i == retries)	/* no success */
71			break;
72		udelay(10);
73	}
74	if (i) {
75		PDEBUG(DBG_I2C,"Needed %d retries for address %#2x", i, addr);
76		PDEBUG(DBG_I2C,"Maybe there's no device at this address");
77	}
78	return ret;
79}
80
81static inline int try_read_address(struct i2c_adapter *i2c_adap,
82				   unsigned char addr, int retries)
83{
84	struct usb_usbvision *usbvision;
85	int i, ret = -1;
86	char buf[4];
87
88	usbvision = (struct usb_usbvision *)i2c_get_adapdata(i2c_adap);
89	for (i = 0; i <= retries; i++) {
90		ret = (usbvision_i2c_read(usbvision, addr, buf, 1));
91		if (ret == 1)
92			break;	/* success! */
93		udelay(5);
94		if (i == retries)	/* no success */
95			break;
96		udelay(10);
97	}
98	if (i) {
99		PDEBUG(DBG_I2C,"Needed %d retries for address %#2x", i, addr);
100		PDEBUG(DBG_I2C,"Maybe there's no device at this address");
101	}
102	return ret;
103}
104
105static inline int usb_find_address(struct i2c_adapter *i2c_adap,
106				   struct i2c_msg *msg, int retries,
107				   unsigned char *add)
108{
109	unsigned short flags = msg->flags;
110
111	unsigned char addr;
112	int ret;
113	if ((flags & I2C_M_TEN)) {
114		/* a ten bit address */
115		addr = 0xf0 | ((msg->addr >> 7) & 0x03);
116		/* try extended address code... */
117		ret = try_write_address(i2c_adap, addr, retries);
118		if (ret != 1) {
119			err("died at extended address code, while writing");
120			return -EREMOTEIO;
121		}
122		add[0] = addr;
123		if (flags & I2C_M_RD) {
124			/* okay, now switch into reading mode */
125			addr |= 0x01;
126			ret = try_read_address(i2c_adap, addr, retries);
127			if (ret != 1) {
128				err("died at extended address code, while reading");
129				return -EREMOTEIO;
130			}
131		}
132
133	} else {		/* normal 7bit address  */
134		addr = (msg->addr << 1);
135		if (flags & I2C_M_RD)
136			addr |= 1;
137
138		add[0] = addr;
139		if (flags & I2C_M_RD)
140			ret = try_read_address(i2c_adap, addr, retries);
141		else
142			ret = try_write_address(i2c_adap, addr, retries);
143
144		if (ret != 1) {
145			return -EREMOTEIO;
146		}
147	}
148	return 0;
149}
150
151static int
152usbvision_i2c_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg msgs[], int num)
153{
154	struct i2c_msg *pmsg;
155	struct usb_usbvision *usbvision;
156	int i, ret;
157	unsigned char addr;
158
159	usbvision = (struct usb_usbvision *)i2c_get_adapdata(i2c_adap);
160
161	for (i = 0; i < num; i++) {
162		pmsg = &msgs[i];
163		ret = usb_find_address(i2c_adap, pmsg, i2c_adap->retries, &addr);
164		if (ret != 0) {
165			PDEBUG(DBG_I2C,"got NAK from device, message #%d", i);
166			return (ret < 0) ? ret : -EREMOTEIO;
167		}
168
169		if (pmsg->flags & I2C_M_RD) {
170			/* read bytes into buffer */
171			ret = (usbvision_i2c_read(usbvision, addr, pmsg->buf, pmsg->len));
172			if (ret < pmsg->len) {
173				return (ret < 0) ? ret : -EREMOTEIO;
174			}
175		} else {
176			/* write bytes from buffer */
177			ret = (usbvision_i2c_write(usbvision, addr, pmsg->buf, pmsg->len));
178			if (ret < pmsg->len) {
179				return (ret < 0) ? ret : -EREMOTEIO;
180			}
181		}
182	}
183	return num;
184}
185
186static int algo_control(struct i2c_adapter *adapter, unsigned int cmd, unsigned long arg)
187{
188	return 0;
189}
190
191static u32 functionality(struct i2c_adapter *adap)
192{
193	return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR;
194}
195
196
197/* -----exported algorithm data: -------------------------------------	*/
198
199static struct i2c_algorithm usbvision_algo = {
200	.master_xfer   = usbvision_i2c_xfer,
201	.smbus_xfer    = NULL,
202	.algo_control  = algo_control,
203	.functionality = functionality,
204};
205
206
207/*
208 * registering functions to load algorithms at runtime
209 */
210static int usbvision_i2c_usb_add_bus(struct i2c_adapter *adap)
211{
212	PDEBUG(DBG_I2C, "I2C   debugging is enabled [i2c]");
213	PDEBUG(DBG_I2C, "ALGO   debugging is enabled [i2c]");
214
215	/* register new adapter to i2c module... */
216
217	adap->algo = &usbvision_algo;
218
219	adap->timeout = 100;	/* default values, should       */
220	adap->retries = 3;	/* be replaced by defines       */
221
222	i2c_add_adapter(adap);
223
224	PDEBUG(DBG_I2C,"i2c bus for %s registered", adap->name);
225
226	return 0;
227}
228
229/* ----------------------------------------------------------------------- */
230/* usbvision specific I2C functions                                        */
231/* ----------------------------------------------------------------------- */
232static struct i2c_adapter i2c_adap_template;
233static struct i2c_client i2c_client_template;
234
235int usbvision_i2c_register(struct usb_usbvision *usbvision)
236{
237	memcpy(&usbvision->i2c_adap, &i2c_adap_template,
238	       sizeof(struct i2c_adapter));
239	memcpy(&usbvision->i2c_client, &i2c_client_template,
240	       sizeof(struct i2c_client));
241
242	sprintf(usbvision->i2c_adap.name + strlen(usbvision->i2c_adap.name),
243		" #%d", usbvision->vdev->minor & 0x1f);
244	PDEBUG(DBG_I2C,"Adaptername: %s", usbvision->i2c_adap.name);
245	usbvision->i2c_adap.dev.parent = &usbvision->dev->dev;
246
247	i2c_set_adapdata(&usbvision->i2c_adap, usbvision);
248	i2c_set_clientdata(&usbvision->i2c_client, usbvision);
249
250	usbvision->i2c_client.adapter = &usbvision->i2c_adap;
251
252	if (usbvision_write_reg(usbvision, USBVISION_SER_MODE, USBVISION_IIC_LRNACK) < 0) {
253		printk(KERN_ERR "usbvision_register: can't write reg\n");
254		return -EBUSY;
255	}
256
257#ifdef CONFIG_MODULES
258	/* Request the load of the i2c modules we need */
259	switch (usbvision_device_data[usbvision->DevModel].Codec) {
260	case CODEC_SAA7113:
261		request_module("saa7115");
262		break;
263	case CODEC_SAA7111:
264		request_module("saa7115");
265		break;
266	}
267	if (usbvision_device_data[usbvision->DevModel].Tuner == 1) {
268		request_module("tuner");
269	}
270#endif
271
272	return usbvision_i2c_usb_add_bus(&usbvision->i2c_adap);
273}
274
275int usbvision_i2c_unregister(struct usb_usbvision *usbvision)
276{
277
278	i2c_del_adapter(&(usbvision->i2c_adap));
279
280	PDEBUG(DBG_I2C,"i2c bus for %s unregistered", usbvision->i2c_adap.name);
281
282	return 0;
283}
284
285void call_i2c_clients(struct usb_usbvision *usbvision, unsigned int cmd,
286		      void *arg)
287{
288	i2c_clients_command(&usbvision->i2c_adap, cmd, arg);
289}
290
291static int attach_inform(struct i2c_client *client)
292{
293	struct usb_usbvision *usbvision;
294
295	usbvision = (struct usb_usbvision *)i2c_get_adapdata(client->adapter);
296
297	switch (client->addr << 1) {
298		case 0x42 << 1:
299		case 0x43 << 1:
300		case 0x4a << 1:
301		case 0x4b << 1:
302			PDEBUG(DBG_I2C,"attach_inform: tda9887 detected.");
303			break;
304		case 0x42:
305			PDEBUG(DBG_I2C,"attach_inform: saa7114 detected.");
306			break;
307		case 0x4a:
308			PDEBUG(DBG_I2C,"attach_inform: saa7113 detected.");
309			break;
310		case 0x48:
311			PDEBUG(DBG_I2C,"attach_inform: saa7111 detected.");
312			break;
313		case 0xa0:
314			PDEBUG(DBG_I2C,"attach_inform: eeprom detected.");
315			break;
316
317		default:
318			{
319				struct tuner_setup tun_setup;
320
321				PDEBUG(DBG_I2C,"attach inform: detected I2C address %x", client->addr << 1);
322				usbvision->tuner_addr = client->addr;
323
324				if ((usbvision->have_tuner) && (usbvision->tuner_type != -1)) {
325					tun_setup.mode_mask = T_ANALOG_TV | T_RADIO;
326					tun_setup.type = usbvision->tuner_type;
327					tun_setup.addr = usbvision->tuner_addr;
328					call_i2c_clients(usbvision, TUNER_SET_TYPE_ADDR, &tun_setup);
329				}
330			}
331			break;
332	}
333	return 0;
334}
335
336static int detach_inform(struct i2c_client *client)
337{
338	struct usb_usbvision *usbvision;
339
340	usbvision = (struct usb_usbvision *)i2c_get_adapdata(client->adapter);
341
342	PDEBUG(DBG_I2C,"usbvision[%d] detaches %s", usbvision->nr, client->name);
343	return 0;
344}
345
346static int
347usbvision_i2c_read_max4(struct usb_usbvision *usbvision, unsigned char addr,
348		     char *buf, short len)
349{
350	int rc, retries;
351
352	for (retries = 5;;) {
353		rc = usbvision_write_reg(usbvision, USBVISION_SER_ADRS, addr);
354		if (rc < 0)
355			return rc;
356
357		/* Initiate byte read cycle                    */
358		/* USBVISION_SER_CONT <- d0-d2 n. of bytes to r/w */
359		/*                    d3 0=Wr 1=Rd             */
360		rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT,
361				      (len & 0x07) | 0x18);
362		if (rc < 0)
363			return rc;
364
365		/* Test for Busy and ACK */
366		do {
367			/* USBVISION_SER_CONT -> d4 == 0 busy */
368			rc = usbvision_read_reg(usbvision, USBVISION_SER_CONT);
369		} while (rc > 0 && ((rc & 0x10) != 0));	/* Retry while busy */
370		if (rc < 0)
371			return rc;
372
373		/* USBVISION_SER_CONT -> d5 == 1 Not ack */
374		if ((rc & 0x20) == 0)	/* Ack? */
375			break;
376
377		/* I2C abort */
378		rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT, 0x00);
379		if (rc < 0)
380			return rc;
381
382		if (--retries < 0)
383			return -1;
384	}
385
386	switch (len) {
387	case 4:
388		buf[3] = usbvision_read_reg(usbvision, USBVISION_SER_DAT4);
389	case 3:
390		buf[2] = usbvision_read_reg(usbvision, USBVISION_SER_DAT3);
391	case 2:
392		buf[1] = usbvision_read_reg(usbvision, USBVISION_SER_DAT2);
393	case 1:
394		buf[0] = usbvision_read_reg(usbvision, USBVISION_SER_DAT1);
395		break;
396	default:
397		printk(KERN_ERR
398		       "usbvision_i2c_read_max4: buffer length > 4\n");
399	}
400
401	if (i2c_debug & DBG_I2C) {
402		int idx;
403		for (idx = 0; idx < len; idx++) {
404			PDEBUG(DBG_I2C,"read %x from address %x", (unsigned char)buf[idx], addr);
405		}
406	}
407	return len;
408}
409
410
411static int usbvision_i2c_write_max4(struct usb_usbvision *usbvision,
412				 unsigned char addr, const char *buf,
413				 short len)
414{
415	int rc, retries;
416	int i;
417	unsigned char value[6];
418	unsigned char ser_cont;
419
420	ser_cont = (len & 0x07) | 0x10;
421
422	value[0] = addr;
423	value[1] = ser_cont;
424	for (i = 0; i < len; i++)
425		value[i + 2] = buf[i];
426
427	for (retries = 5;;) {
428		rc = usb_control_msg(usbvision->dev,
429				     usb_sndctrlpipe(usbvision->dev, 1),
430				     USBVISION_OP_CODE,
431				     USB_DIR_OUT | USB_TYPE_VENDOR |
432				     USB_RECIP_ENDPOINT, 0,
433				     (__u16) USBVISION_SER_ADRS, value,
434				     len + 2, HZ);
435
436		if (rc < 0)
437			return rc;
438
439		rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT,
440				      (len & 0x07) | 0x10);
441		if (rc < 0)
442			return rc;
443
444		/* Test for Busy and ACK */
445		do {
446			rc = usbvision_read_reg(usbvision, USBVISION_SER_CONT);
447		} while (rc > 0 && ((rc & 0x10) != 0));	/* Retry while busy */
448		if (rc < 0)
449			return rc;
450
451		if ((rc & 0x20) == 0)	/* Ack? */
452			break;
453
454		/* I2C abort */
455		usbvision_write_reg(usbvision, USBVISION_SER_CONT, 0x00);
456
457		if (--retries < 0)
458			return -1;
459
460	}
461
462	if (i2c_debug & DBG_I2C) {
463		int idx;
464		for (idx = 0; idx < len; idx++) {
465			PDEBUG(DBG_I2C,"wrote %x at address %x", (unsigned char)buf[idx], addr);
466		}
467	}
468	return len;
469}
470
471static int usbvision_i2c_write(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
472			    short len)
473{
474	char *bufPtr = buf;
475	int retval;
476	int wrcount = 0;
477	int count;
478	int maxLen = 4;
479
480	while (len > 0) {
481		count = (len > maxLen) ? maxLen : len;
482		retval = usbvision_i2c_write_max4(usbvision, addr, bufPtr, count);
483		if (retval > 0) {
484			len -= count;
485			bufPtr += count;
486			wrcount += count;
487		} else
488			return (retval < 0) ? retval : -EFAULT;
489	}
490	return wrcount;
491}
492
493static int usbvision_i2c_read(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
494			   short len)
495{
496	char temp[4];
497	int retval, i;
498	int rdcount = 0;
499	int count;
500
501	while (len > 0) {
502		count = (len > 3) ? 4 : len;
503		retval = usbvision_i2c_read_max4(usbvision, addr, temp, count);
504		if (retval > 0) {
505			for (i = 0; i < len; i++)
506				buf[rdcount + i] = temp[i];
507			len -= count;
508			rdcount += count;
509		} else
510			return (retval < 0) ? retval : -EFAULT;
511	}
512	return rdcount;
513}
514
515static struct i2c_adapter i2c_adap_template = {
516	.owner = THIS_MODULE,
517	.name              = "usbvision",
518	.id                = I2C_HW_B_BT848, /* FIXME */
519	.client_register   = attach_inform,
520	.client_unregister = detach_inform,
521#ifdef I2C_ADAP_CLASS_TV_ANALOG
522	.class             = I2C_ADAP_CLASS_TV_ANALOG,
523#else
524	.class		   = I2C_CLASS_TV_ANALOG,
525#endif
526};
527
528static struct i2c_client i2c_client_template = {
529	.name		= "usbvision internal",
530};
531
532/*
533 * Overrides for Emacs so that we follow Linus's tabbing style.
534 * ---------------------------------------------------------------------------
535 * Local variables:
536 * c-basic-offset: 8
537 * End:
538 */
539