usbvision-i2c.c revision ff699e6bd02eb1c6d02c7c2b576c2ee6caab201c 
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;
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 u32 functionality(struct i2c_adapter *adap)
187{
188	return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR;
189}
190
191
192/* -----exported algorithm data: -------------------------------------	*/
193
194static struct i2c_algorithm usbvision_algo = {
195	.master_xfer   = usbvision_i2c_xfer,
196	.smbus_xfer    = NULL,
197	.functionality = functionality,
198};
199
200
201/*
202 * registering functions to load algorithms at runtime
203 */
204static int usbvision_i2c_usb_add_bus(struct i2c_adapter *adap)
205{
206	PDEBUG(DBG_I2C, "I2C   debugging is enabled [i2c]");
207	PDEBUG(DBG_I2C, "ALGO   debugging is enabled [i2c]");
208
209	/* register new adapter to i2c module... */
210
211	adap->algo = &usbvision_algo;
212
213	adap->timeout = 100;	/* default values, should       */
214	adap->retries = 3;	/* be replaced by defines       */
215
216	i2c_add_adapter(adap);
217
218	PDEBUG(DBG_I2C,"i2c bus for %s registered", adap->name);
219
220	return 0;
221}
222
223/* ----------------------------------------------------------------------- */
224/* usbvision specific I2C functions                                        */
225/* ----------------------------------------------------------------------- */
226static struct i2c_adapter i2c_adap_template;
227static struct i2c_client i2c_client_template;
228
229int usbvision_i2c_register(struct usb_usbvision *usbvision)
230{
231	memcpy(&usbvision->i2c_adap, &i2c_adap_template,
232	       sizeof(struct i2c_adapter));
233	memcpy(&usbvision->i2c_client, &i2c_client_template,
234	       sizeof(struct i2c_client));
235
236	sprintf(usbvision->i2c_adap.name + strlen(usbvision->i2c_adap.name),
237		" #%d", usbvision->vdev->minor & 0x1f);
238	PDEBUG(DBG_I2C,"Adaptername: %s", usbvision->i2c_adap.name);
239	usbvision->i2c_adap.dev.parent = &usbvision->dev->dev;
240
241	i2c_set_adapdata(&usbvision->i2c_adap, usbvision);
242	i2c_set_clientdata(&usbvision->i2c_client, usbvision);
243
244	usbvision->i2c_client.adapter = &usbvision->i2c_adap;
245
246	if (usbvision_write_reg(usbvision, USBVISION_SER_MODE, USBVISION_IIC_LRNACK) < 0) {
247		printk(KERN_ERR "usbvision_register: can't write reg\n");
248		return -EBUSY;
249	}
250
251#ifdef CONFIG_MODULES
252	/* Request the load of the i2c modules we need */
253	switch (usbvision_device_data[usbvision->DevModel].Codec) {
254	case CODEC_SAA7113:
255		request_module("saa7115");
256		break;
257	case CODEC_SAA7111:
258		request_module("saa7115");
259		break;
260	}
261	if (usbvision_device_data[usbvision->DevModel].Tuner == 1) {
262		request_module("tuner");
263	}
264#endif
265
266	return usbvision_i2c_usb_add_bus(&usbvision->i2c_adap);
267}
268
269int usbvision_i2c_unregister(struct usb_usbvision *usbvision)
270{
271
272	i2c_del_adapter(&(usbvision->i2c_adap));
273
274	PDEBUG(DBG_I2C,"i2c bus for %s unregistered", usbvision->i2c_adap.name);
275
276	return 0;
277}
278
279void call_i2c_clients(struct usb_usbvision *usbvision, unsigned int cmd,
280		      void *arg)
281{
282	i2c_clients_command(&usbvision->i2c_adap, cmd, arg);
283}
284
285static int attach_inform(struct i2c_client *client)
286{
287	struct usb_usbvision *usbvision;
288
289	usbvision = (struct usb_usbvision *)i2c_get_adapdata(client->adapter);
290
291	switch (client->addr << 1) {
292		case 0x42 << 1:
293		case 0x43 << 1:
294		case 0x4a << 1:
295		case 0x4b << 1:
296			PDEBUG(DBG_I2C,"attach_inform: tda9887 detected.");
297			break;
298		case 0x42:
299			PDEBUG(DBG_I2C,"attach_inform: saa7114 detected.");
300			break;
301		case 0x4a:
302			PDEBUG(DBG_I2C,"attach_inform: saa7113 detected.");
303			break;
304		case 0x48:
305			PDEBUG(DBG_I2C,"attach_inform: saa7111 detected.");
306			break;
307		case 0xa0:
308			PDEBUG(DBG_I2C,"attach_inform: eeprom detected.");
309			break;
310
311		default:
312			{
313				struct tuner_setup tun_setup;
314
315				PDEBUG(DBG_I2C,"attach inform: detected I2C address %x", client->addr << 1);
316				usbvision->tuner_addr = client->addr;
317
318				if ((usbvision->have_tuner) && (usbvision->tuner_type != -1)) {
319					tun_setup.mode_mask = T_ANALOG_TV | T_RADIO;
320					tun_setup.type = usbvision->tuner_type;
321					tun_setup.addr = usbvision->tuner_addr;
322					call_i2c_clients(usbvision, TUNER_SET_TYPE_ADDR, &tun_setup);
323				}
324			}
325			break;
326	}
327	return 0;
328}
329
330static int detach_inform(struct i2c_client *client)
331{
332	struct usb_usbvision *usbvision;
333
334	usbvision = (struct usb_usbvision *)i2c_get_adapdata(client->adapter);
335
336	PDEBUG(DBG_I2C,"usbvision[%d] detaches %s", usbvision->nr, client->name);
337	return 0;
338}
339
340static int
341usbvision_i2c_read_max4(struct usb_usbvision *usbvision, unsigned char addr,
342		     char *buf, short len)
343{
344	int rc, retries;
345
346	for (retries = 5;;) {
347		rc = usbvision_write_reg(usbvision, USBVISION_SER_ADRS, addr);
348		if (rc < 0)
349			return rc;
350
351		/* Initiate byte read cycle                    */
352		/* USBVISION_SER_CONT <- d0-d2 n. of bytes to r/w */
353		/*                    d3 0=Wr 1=Rd             */
354		rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT,
355				      (len & 0x07) | 0x18);
356		if (rc < 0)
357			return rc;
358
359		/* Test for Busy and ACK */
360		do {
361			/* USBVISION_SER_CONT -> d4 == 0 busy */
362			rc = usbvision_read_reg(usbvision, USBVISION_SER_CONT);
363		} while (rc > 0 && ((rc & 0x10) != 0));	/* Retry while busy */
364		if (rc < 0)
365			return rc;
366
367		/* USBVISION_SER_CONT -> d5 == 1 Not ack */
368		if ((rc & 0x20) == 0)	/* Ack? */
369			break;
370
371		/* I2C abort */
372		rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT, 0x00);
373		if (rc < 0)
374			return rc;
375
376		if (--retries < 0)
377			return -1;
378	}
379
380	switch (len) {
381	case 4:
382		buf[3] = usbvision_read_reg(usbvision, USBVISION_SER_DAT4);
383	case 3:
384		buf[2] = usbvision_read_reg(usbvision, USBVISION_SER_DAT3);
385	case 2:
386		buf[1] = usbvision_read_reg(usbvision, USBVISION_SER_DAT2);
387	case 1:
388		buf[0] = usbvision_read_reg(usbvision, USBVISION_SER_DAT1);
389		break;
390	default:
391		printk(KERN_ERR
392		       "usbvision_i2c_read_max4: buffer length > 4\n");
393	}
394
395	if (i2c_debug & DBG_I2C) {
396		int idx;
397		for (idx = 0; idx < len; idx++) {
398			PDEBUG(DBG_I2C,"read %x from address %x", (unsigned char)buf[idx], addr);
399		}
400	}
401	return len;
402}
403
404
405static int usbvision_i2c_write_max4(struct usb_usbvision *usbvision,
406				 unsigned char addr, const char *buf,
407				 short len)
408{
409	int rc, retries;
410	int i;
411	unsigned char value[6];
412	unsigned char ser_cont;
413
414	ser_cont = (len & 0x07) | 0x10;
415
416	value[0] = addr;
417	value[1] = ser_cont;
418	for (i = 0; i < len; i++)
419		value[i + 2] = buf[i];
420
421	for (retries = 5;;) {
422		rc = usb_control_msg(usbvision->dev,
423				     usb_sndctrlpipe(usbvision->dev, 1),
424				     USBVISION_OP_CODE,
425				     USB_DIR_OUT | USB_TYPE_VENDOR |
426				     USB_RECIP_ENDPOINT, 0,
427				     (__u16) USBVISION_SER_ADRS, value,
428				     len + 2, HZ);
429
430		if (rc < 0)
431			return rc;
432
433		rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT,
434				      (len & 0x07) | 0x10);
435		if (rc < 0)
436			return rc;
437
438		/* Test for Busy and ACK */
439		do {
440			rc = usbvision_read_reg(usbvision, USBVISION_SER_CONT);
441		} while (rc > 0 && ((rc & 0x10) != 0));	/* Retry while busy */
442		if (rc < 0)
443			return rc;
444
445		if ((rc & 0x20) == 0)	/* Ack? */
446			break;
447
448		/* I2C abort */
449		usbvision_write_reg(usbvision, USBVISION_SER_CONT, 0x00);
450
451		if (--retries < 0)
452			return -1;
453
454	}
455
456	if (i2c_debug & DBG_I2C) {
457		int idx;
458		for (idx = 0; idx < len; idx++) {
459			PDEBUG(DBG_I2C,"wrote %x at address %x", (unsigned char)buf[idx], addr);
460		}
461	}
462	return len;
463}
464
465static int usbvision_i2c_write(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
466			    short len)
467{
468	char *bufPtr = buf;
469	int retval;
470	int wrcount = 0;
471	int count;
472	int maxLen = 4;
473
474	while (len > 0) {
475		count = (len > maxLen) ? maxLen : len;
476		retval = usbvision_i2c_write_max4(usbvision, addr, bufPtr, count);
477		if (retval > 0) {
478			len -= count;
479			bufPtr += count;
480			wrcount += count;
481		} else
482			return (retval < 0) ? retval : -EFAULT;
483	}
484	return wrcount;
485}
486
487static int usbvision_i2c_read(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
488			   short len)
489{
490	char temp[4];
491	int retval, i;
492	int rdcount = 0;
493	int count;
494
495	while (len > 0) {
496		count = (len > 3) ? 4 : len;
497		retval = usbvision_i2c_read_max4(usbvision, addr, temp, count);
498		if (retval > 0) {
499			for (i = 0; i < len; i++)
500				buf[rdcount + i] = temp[i];
501			len -= count;
502			rdcount += count;
503		} else
504			return (retval < 0) ? retval : -EFAULT;
505	}
506	return rdcount;
507}
508
509static struct i2c_adapter i2c_adap_template = {
510	.owner = THIS_MODULE,
511	.name              = "usbvision",
512	.id                = I2C_HW_B_BT848, /* FIXME */
513	.client_register   = attach_inform,
514	.client_unregister = detach_inform,
515#ifdef I2C_ADAP_CLASS_TV_ANALOG
516	.class             = I2C_ADAP_CLASS_TV_ANALOG,
517#else
518	.class		   = I2C_CLASS_TV_ANALOG,
519#endif
520};
521
522static struct i2c_client i2c_client_template = {
523	.name		= "usbvision internal",
524};
525
526/*
527 * Overrides for Emacs so that we follow Linus's tabbing style.
528 * ---------------------------------------------------------------------------
529 * Local variables:
530 * c-basic-offset: 8
531 * End:
532 */
533