usbvision-i2c.c revision 0fda5d4420fe1d6a19189386b6bc6532c97a7e0e 
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/init.h>
32#include <asm/uaccess.h>
33#include <linux/ioport.h>
34#include <linux/errno.h>
35#include <linux/usb.h>
36#include <linux/i2c.h>
37#include "usbvision.h"
38
39#define DBG_I2C		1<<0
40
41static int i2c_debug;
42
43module_param (i2c_debug, int, 0644);			// debug_i2c_usb mode of the device driver
44MODULE_PARM_DESC(i2c_debug, "enable debug messages [i2c]");
45
46#define PDEBUG(level, fmt, args...) { \
47		if (i2c_debug & (level)) \
48			printk(KERN_INFO KBUILD_MODNAME ":[%s:%d] " fmt, \
49				__func__, __LINE__ , ## args); \
50	}
51
52static int usbvision_i2c_write(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
53			    short len);
54static int usbvision_i2c_read(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
55			   short len);
56
57static inline int try_write_address(struct i2c_adapter *i2c_adap,
58				    unsigned char addr, int retries)
59{
60	struct usb_usbvision *usbvision;
61	int i, ret = -1;
62	char buf[4];
63
64	usbvision = (struct usb_usbvision *)i2c_get_adapdata(i2c_adap);
65	buf[0] = 0x00;
66	for (i = 0; i <= retries; i++) {
67		ret = (usbvision_i2c_write(usbvision, addr, buf, 1));
68		if (ret == 1)
69			break;	/* success! */
70		udelay(5);
71		if (i == retries)	/* no success */
72			break;
73		udelay(10);
74	}
75	if (i) {
76		PDEBUG(DBG_I2C,"Needed %d retries for address %#2x", i, addr);
77		PDEBUG(DBG_I2C,"Maybe there's no device at this address");
78	}
79	return ret;
80}
81
82static inline int try_read_address(struct i2c_adapter *i2c_adap,
83				   unsigned char addr, int retries)
84{
85	struct usb_usbvision *usbvision;
86	int i, ret = -1;
87	char buf[4];
88
89	usbvision = (struct usb_usbvision *)i2c_get_adapdata(i2c_adap);
90	for (i = 0; i <= retries; i++) {
91		ret = (usbvision_i2c_read(usbvision, addr, buf, 1));
92		if (ret == 1)
93			break;	/* success! */
94		udelay(5);
95		if (i == retries)	/* no success */
96			break;
97		udelay(10);
98	}
99	if (i) {
100		PDEBUG(DBG_I2C,"Needed %d retries for address %#2x", i, addr);
101		PDEBUG(DBG_I2C,"Maybe there's no device at this address");
102	}
103	return ret;
104}
105
106static inline int usb_find_address(struct i2c_adapter *i2c_adap,
107				   struct i2c_msg *msg, int retries,
108				   unsigned char *add)
109{
110	unsigned short flags = msg->flags;
111
112	unsigned char addr;
113	int ret;
114	if ((flags & I2C_M_TEN)) {
115		/* a ten bit address */
116		addr = 0xf0 | ((msg->addr >> 7) & 0x03);
117		/* try extended address code... */
118		ret = try_write_address(i2c_adap, addr, retries);
119		if (ret != 1) {
120			dev_err(&i2c_adap->dev,
121				"died at extended address code,	while writing\n");
122			return -EREMOTEIO;
123		}
124		add[0] = addr;
125		if (flags & I2C_M_RD) {
126			/* okay, now switch into reading mode */
127			addr |= 0x01;
128			ret = try_read_address(i2c_adap, addr, retries);
129			if (ret != 1) {
130				dev_err(&i2c_adap->dev,
131					"died at extended address code, while reading\n");
132				return -EREMOTEIO;
133			}
134		}
135
136	} else {		/* normal 7bit address  */
137		addr = (msg->addr << 1);
138		if (flags & I2C_M_RD)
139			addr |= 1;
140
141		add[0] = addr;
142		if (flags & I2C_M_RD)
143			ret = try_read_address(i2c_adap, addr, retries);
144		else
145			ret = try_write_address(i2c_adap, addr, retries);
146
147		if (ret != 1) {
148			return -EREMOTEIO;
149		}
150	}
151	return 0;
152}
153
154static int
155usbvision_i2c_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg msgs[], int num)
156{
157	struct i2c_msg *pmsg;
158	struct usb_usbvision *usbvision;
159	int i, ret;
160	unsigned char addr = 0;
161
162	usbvision = (struct usb_usbvision *)i2c_get_adapdata(i2c_adap);
163
164	for (i = 0; i < num; i++) {
165		pmsg = &msgs[i];
166		ret = usb_find_address(i2c_adap, pmsg, i2c_adap->retries, &addr);
167		if (ret != 0) {
168			PDEBUG(DBG_I2C,"got NAK from device, message #%d", i);
169			return (ret < 0) ? ret : -EREMOTEIO;
170		}
171
172		if (pmsg->flags & I2C_M_RD) {
173			/* read bytes into buffer */
174			ret = (usbvision_i2c_read(usbvision, addr, pmsg->buf, pmsg->len));
175			if (ret < pmsg->len) {
176				return (ret < 0) ? ret : -EREMOTEIO;
177			}
178		} else {
179			/* write bytes from buffer */
180			ret = (usbvision_i2c_write(usbvision, addr, pmsg->buf, pmsg->len));
181			if (ret < pmsg->len) {
182				return (ret < 0) ? ret : -EREMOTEIO;
183			}
184		}
185	}
186	return num;
187}
188
189static u32 functionality(struct i2c_adapter *adap)
190{
191	return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR;
192}
193
194/* -----exported algorithm data: -------------------------------------	*/
195
196static struct i2c_algorithm usbvision_algo = {
197	.master_xfer   = usbvision_i2c_xfer,
198	.smbus_xfer    = NULL,
199	.functionality = functionality,
200};
201
202
203/* ----------------------------------------------------------------------- */
204/* usbvision specific I2C functions                                        */
205/* ----------------------------------------------------------------------- */
206static struct i2c_adapter i2c_adap_template;
207
208int usbvision_i2c_register(struct usb_usbvision *usbvision)
209{
210	static unsigned short saa711x_addrs[] = {
211		0x4a >> 1, 0x48 >> 1,	/* SAA7111, SAA7111A and SAA7113 */
212		0x42 >> 1, 0x40 >> 1,	/* SAA7114, SAA7115 and SAA7118 */
213		I2C_CLIENT_END };
214
215	memcpy(&usbvision->i2c_adap, &i2c_adap_template,
216	       sizeof(struct i2c_adapter));
217
218	sprintf(usbvision->i2c_adap.name, "%s-%d-%s", i2c_adap_template.name,
219		usbvision->dev->bus->busnum, usbvision->dev->devpath);
220	PDEBUG(DBG_I2C,"Adaptername: %s", usbvision->i2c_adap.name);
221	usbvision->i2c_adap.dev.parent = &usbvision->dev->dev;
222
223	i2c_set_adapdata(&usbvision->i2c_adap, &usbvision->v4l2_dev);
224
225	if (usbvision_write_reg(usbvision, USBVISION_SER_MODE, USBVISION_IIC_LRNACK) < 0) {
226		printk(KERN_ERR "usbvision_register: can't write reg\n");
227		return -EBUSY;
228	}
229
230	PDEBUG(DBG_I2C, "I2C   debugging is enabled [i2c]");
231	PDEBUG(DBG_I2C, "ALGO   debugging is enabled [i2c]");
232
233	/* register new adapter to i2c module... */
234
235	usbvision->i2c_adap.algo = &usbvision_algo;
236
237	usbvision->i2c_adap.timeout = 100;	/* default values, should       */
238	usbvision->i2c_adap.retries = 3;	/* be replaced by defines       */
239
240	i2c_add_adapter(&usbvision->i2c_adap);
241
242	PDEBUG(DBG_I2C, "i2c bus for %s registered", usbvision->i2c_adap.name);
243
244	/* Request the load of the i2c modules we need */
245	switch (usbvision_device_data[usbvision->DevModel].Codec) {
246	case CODEC_SAA7113:
247	case CODEC_SAA7111:
248		v4l2_i2c_new_subdev(&usbvision->v4l2_dev,
249				&usbvision->i2c_adap, "saa7115",
250				"saa7115_auto", 0, saa711x_addrs);
251		break;
252	}
253	if (usbvision_device_data[usbvision->DevModel].Tuner == 1) {
254		struct v4l2_subdev *sd;
255		enum v4l2_i2c_tuner_type type;
256		struct tuner_setup tun_setup;
257
258		sd = v4l2_i2c_new_subdev(&usbvision->v4l2_dev,
259				&usbvision->i2c_adap, "tuner",
260				"tuner", 0, v4l2_i2c_tuner_addrs(ADDRS_DEMOD));
261		/* depending on whether we found a demod or not, select
262		   the tuner type. */
263		type = sd ? ADDRS_TV_WITH_DEMOD : ADDRS_TV;
264
265		sd = v4l2_i2c_new_subdev(&usbvision->v4l2_dev,
266				&usbvision->i2c_adap, "tuner",
267				"tuner", 0, v4l2_i2c_tuner_addrs(type));
268
269		if (usbvision->tuner_type != -1) {
270			tun_setup.mode_mask = T_ANALOG_TV | T_RADIO;
271			tun_setup.type = usbvision->tuner_type;
272			tun_setup.addr = v4l2_i2c_subdev_addr(sd);
273			call_all(usbvision, tuner, s_type_addr, &tun_setup);
274		}
275	}
276
277	return 0;
278}
279
280int usbvision_i2c_unregister(struct usb_usbvision *usbvision)
281{
282
283	i2c_del_adapter(&(usbvision->i2c_adap));
284
285	PDEBUG(DBG_I2C,"i2c bus for %s unregistered", usbvision->i2c_adap.name);
286
287	return 0;
288}
289
290static int
291usbvision_i2c_read_max4(struct usb_usbvision *usbvision, unsigned char addr,
292		     char *buf, short len)
293{
294	int rc, retries;
295
296	for (retries = 5;;) {
297		rc = usbvision_write_reg(usbvision, USBVISION_SER_ADRS, addr);
298		if (rc < 0)
299			return rc;
300
301		/* Initiate byte read cycle                    */
302		/* USBVISION_SER_CONT <- d0-d2 n. of bytes to r/w */
303		/*                    d3 0=Wr 1=Rd             */
304		rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT,
305				      (len & 0x07) | 0x18);
306		if (rc < 0)
307			return rc;
308
309		/* Test for Busy and ACK */
310		do {
311			/* USBVISION_SER_CONT -> d4 == 0 busy */
312			rc = usbvision_read_reg(usbvision, USBVISION_SER_CONT);
313		} while (rc > 0 && ((rc & 0x10) != 0));	/* Retry while busy */
314		if (rc < 0)
315			return rc;
316
317		/* USBVISION_SER_CONT -> d5 == 1 Not ack */
318		if ((rc & 0x20) == 0)	/* Ack? */
319			break;
320
321		/* I2C abort */
322		rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT, 0x00);
323		if (rc < 0)
324			return rc;
325
326		if (--retries < 0)
327			return -1;
328	}
329
330	switch (len) {
331	case 4:
332		buf[3] = usbvision_read_reg(usbvision, USBVISION_SER_DAT4);
333	case 3:
334		buf[2] = usbvision_read_reg(usbvision, USBVISION_SER_DAT3);
335	case 2:
336		buf[1] = usbvision_read_reg(usbvision, USBVISION_SER_DAT2);
337	case 1:
338		buf[0] = usbvision_read_reg(usbvision, USBVISION_SER_DAT1);
339		break;
340	default:
341		printk(KERN_ERR
342		       "usbvision_i2c_read_max4: buffer length > 4\n");
343	}
344
345	if (i2c_debug & DBG_I2C) {
346		int idx;
347		for (idx = 0; idx < len; idx++) {
348			PDEBUG(DBG_I2C,"read %x from address %x", (unsigned char)buf[idx], addr);
349		}
350	}
351	return len;
352}
353
354
355static int usbvision_i2c_write_max4(struct usb_usbvision *usbvision,
356				 unsigned char addr, const char *buf,
357				 short len)
358{
359	int rc, retries;
360	int i;
361	unsigned char value[6];
362	unsigned char ser_cont;
363
364	ser_cont = (len & 0x07) | 0x10;
365
366	value[0] = addr;
367	value[1] = ser_cont;
368	for (i = 0; i < len; i++)
369		value[i + 2] = buf[i];
370
371	for (retries = 5;;) {
372		rc = usb_control_msg(usbvision->dev,
373				     usb_sndctrlpipe(usbvision->dev, 1),
374				     USBVISION_OP_CODE,
375				     USB_DIR_OUT | USB_TYPE_VENDOR |
376				     USB_RECIP_ENDPOINT, 0,
377				     (__u16) USBVISION_SER_ADRS, value,
378				     len + 2, HZ);
379
380		if (rc < 0)
381			return rc;
382
383		rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT,
384				      (len & 0x07) | 0x10);
385		if (rc < 0)
386			return rc;
387
388		/* Test for Busy and ACK */
389		do {
390			rc = usbvision_read_reg(usbvision, USBVISION_SER_CONT);
391		} while (rc > 0 && ((rc & 0x10) != 0));	/* Retry while busy */
392		if (rc < 0)
393			return rc;
394
395		if ((rc & 0x20) == 0)	/* Ack? */
396			break;
397
398		/* I2C abort */
399		usbvision_write_reg(usbvision, USBVISION_SER_CONT, 0x00);
400
401		if (--retries < 0)
402			return -1;
403
404	}
405
406	if (i2c_debug & DBG_I2C) {
407		int idx;
408		for (idx = 0; idx < len; idx++) {
409			PDEBUG(DBG_I2C,"wrote %x at address %x", (unsigned char)buf[idx], addr);
410		}
411	}
412	return len;
413}
414
415static int usbvision_i2c_write(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
416			    short len)
417{
418	char *bufPtr = buf;
419	int retval;
420	int wrcount = 0;
421	int count;
422	int maxLen = 4;
423
424	while (len > 0) {
425		count = (len > maxLen) ? maxLen : len;
426		retval = usbvision_i2c_write_max4(usbvision, addr, bufPtr, count);
427		if (retval > 0) {
428			len -= count;
429			bufPtr += count;
430			wrcount += count;
431		} else
432			return (retval < 0) ? retval : -EFAULT;
433	}
434	return wrcount;
435}
436
437static int usbvision_i2c_read(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
438			   short len)
439{
440	char temp[4];
441	int retval, i;
442	int rdcount = 0;
443	int count;
444
445	while (len > 0) {
446		count = (len > 3) ? 4 : len;
447		retval = usbvision_i2c_read_max4(usbvision, addr, temp, count);
448		if (retval > 0) {
449			for (i = 0; i < len; i++)
450				buf[rdcount + i] = temp[i];
451			len -= count;
452			rdcount += count;
453		} else
454			return (retval < 0) ? retval : -EFAULT;
455	}
456	return rdcount;
457}
458
459static struct i2c_adapter i2c_adap_template = {
460	.owner = THIS_MODULE,
461	.name              = "usbvision",
462};
463
464/*
465 * Overrides for Emacs so that we follow Linus's tabbing style.
466 * ---------------------------------------------------------------------------
467 * Local variables:
468 * c-basic-offset: 8
469 * End:
470 */
471