usbvision-i2c.c revision f2caedd919bfef6abe9ad99cf3e210615f6a692d 
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/utsname.h>
32#include <linux/init.h>
33#include <asm/uaccess.h>
34#include <linux/ioport.h>
35#include <linux/errno.h>
36#include <linux/usb.h>
37#include <linux/i2c.h>
38#include "usbvision.h"
39
40#define DBG_I2C		1<<0
41
42static int i2c_debug;
43
44module_param (i2c_debug, int, 0644);			// debug_i2c_usb mode of the device driver
45MODULE_PARM_DESC(i2c_debug, "enable debug messages [i2c]");
46
47#define PDEBUG(level, fmt, args...) { \
48		if (i2c_debug & (level)) \
49			printk(KERN_INFO KBUILD_MODNAME ":[%s:%d] " fmt, \
50				__func__, __LINE__ , ## args); \
51	}
52
53static int usbvision_i2c_write(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
54			    short len);
55static int usbvision_i2c_read(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
56			   short len);
57
58static inline int try_write_address(struct i2c_adapter *i2c_adap,
59				    unsigned char addr, int retries)
60{
61	struct usb_usbvision *usbvision;
62	int i, ret = -1;
63	char buf[4];
64
65	usbvision = (struct usb_usbvision *)i2c_get_adapdata(i2c_adap);
66	buf[0] = 0x00;
67	for (i = 0; i <= retries; i++) {
68		ret = (usbvision_i2c_write(usbvision, addr, buf, 1));
69		if (ret == 1)
70			break;	/* success! */
71		udelay(5);
72		if (i == retries)	/* no success */
73			break;
74		udelay(10);
75	}
76	if (i) {
77		PDEBUG(DBG_I2C,"Needed %d retries for address %#2x", i, addr);
78		PDEBUG(DBG_I2C,"Maybe there's no device at this address");
79	}
80	return ret;
81}
82
83static inline int try_read_address(struct i2c_adapter *i2c_adap,
84				   unsigned char addr, int retries)
85{
86	struct usb_usbvision *usbvision;
87	int i, ret = -1;
88	char buf[4];
89
90	usbvision = (struct usb_usbvision *)i2c_get_adapdata(i2c_adap);
91	for (i = 0; i <= retries; i++) {
92		ret = (usbvision_i2c_read(usbvision, addr, buf, 1));
93		if (ret == 1)
94			break;	/* success! */
95		udelay(5);
96		if (i == retries)	/* no success */
97			break;
98		udelay(10);
99	}
100	if (i) {
101		PDEBUG(DBG_I2C,"Needed %d retries for address %#2x", i, addr);
102		PDEBUG(DBG_I2C,"Maybe there's no device at this address");
103	}
104	return ret;
105}
106
107static inline int usb_find_address(struct i2c_adapter *i2c_adap,
108				   struct i2c_msg *msg, int retries,
109				   unsigned char *add)
110{
111	unsigned short flags = msg->flags;
112
113	unsigned char addr;
114	int ret;
115	if ((flags & I2C_M_TEN)) {
116		/* a ten bit address */
117		addr = 0xf0 | ((msg->addr >> 7) & 0x03);
118		/* try extended address code... */
119		ret = try_write_address(i2c_adap, addr, retries);
120		if (ret != 1) {
121			dev_err(&i2c_adap->dev,
122				"died at extended address code,	while writing\n");
123			return -EREMOTEIO;
124		}
125		add[0] = addr;
126		if (flags & I2C_M_RD) {
127			/* okay, now switch into reading mode */
128			addr |= 0x01;
129			ret = try_read_address(i2c_adap, addr, retries);
130			if (ret != 1) {
131				dev_err(&i2c_adap->dev,
132					"died at extended address code, while reading\n");
133				return -EREMOTEIO;
134			}
135		}
136
137	} else {		/* normal 7bit address  */
138		addr = (msg->addr << 1);
139		if (flags & I2C_M_RD)
140			addr |= 1;
141
142		add[0] = addr;
143		if (flags & I2C_M_RD)
144			ret = try_read_address(i2c_adap, addr, retries);
145		else
146			ret = try_write_address(i2c_adap, addr, retries);
147
148		if (ret != 1) {
149			return -EREMOTEIO;
150		}
151	}
152	return 0;
153}
154
155static int
156usbvision_i2c_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg msgs[], int num)
157{
158	struct i2c_msg *pmsg;
159	struct usb_usbvision *usbvision;
160	int i, ret;
161	unsigned char addr = 0;
162
163	usbvision = (struct usb_usbvision *)i2c_get_adapdata(i2c_adap);
164
165	for (i = 0; i < num; i++) {
166		pmsg = &msgs[i];
167		ret = usb_find_address(i2c_adap, pmsg, i2c_adap->retries, &addr);
168		if (ret != 0) {
169			PDEBUG(DBG_I2C,"got NAK from device, message #%d", i);
170			return (ret < 0) ? ret : -EREMOTEIO;
171		}
172
173		if (pmsg->flags & I2C_M_RD) {
174			/* read bytes into buffer */
175			ret = (usbvision_i2c_read(usbvision, addr, pmsg->buf, pmsg->len));
176			if (ret < pmsg->len) {
177				return (ret < 0) ? ret : -EREMOTEIO;
178			}
179		} else {
180			/* write bytes from buffer */
181			ret = (usbvision_i2c_write(usbvision, addr, pmsg->buf, pmsg->len));
182			if (ret < pmsg->len) {
183				return (ret < 0) ? ret : -EREMOTEIO;
184			}
185		}
186	}
187	return num;
188}
189
190static u32 functionality(struct i2c_adapter *adap)
191{
192	return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR;
193}
194
195/* -----exported algorithm data: -------------------------------------	*/
196
197static struct i2c_algorithm usbvision_algo = {
198	.master_xfer   = usbvision_i2c_xfer,
199	.smbus_xfer    = NULL,
200	.functionality = functionality,
201};
202
203
204/* ----------------------------------------------------------------------- */
205/* usbvision specific I2C functions                                        */
206/* ----------------------------------------------------------------------- */
207static struct i2c_adapter i2c_adap_template;
208
209int usbvision_i2c_register(struct usb_usbvision *usbvision)
210{
211	static unsigned short saa711x_addrs[] = {
212		0x4a >> 1, 0x48 >> 1,	/* SAA7111, SAA7111A and SAA7113 */
213		0x42 >> 1, 0x40 >> 1,	/* SAA7114, SAA7115 and SAA7118 */
214		I2C_CLIENT_END };
215
216	memcpy(&usbvision->i2c_adap, &i2c_adap_template,
217	       sizeof(struct i2c_adapter));
218
219	sprintf(usbvision->i2c_adap.name + strlen(usbvision->i2c_adap.name),
220		" #%d", usbvision->vdev->num);
221	PDEBUG(DBG_I2C,"Adaptername: %s", usbvision->i2c_adap.name);
222	usbvision->i2c_adap.dev.parent = &usbvision->dev->dev;
223
224	i2c_set_adapdata(&usbvision->i2c_adap, &usbvision->v4l2_dev);
225
226	if (usbvision_write_reg(usbvision, USBVISION_SER_MODE, USBVISION_IIC_LRNACK) < 0) {
227		printk(KERN_ERR "usbvision_register: can't write reg\n");
228		return -EBUSY;
229	}
230
231	PDEBUG(DBG_I2C, "I2C   debugging is enabled [i2c]");
232	PDEBUG(DBG_I2C, "ALGO   debugging is enabled [i2c]");
233
234	/* register new adapter to i2c module... */
235
236	usbvision->i2c_adap.algo = &usbvision_algo;
237
238	usbvision->i2c_adap.timeout = 100;	/* default values, should       */
239	usbvision->i2c_adap.retries = 3;	/* be replaced by defines       */
240
241	i2c_add_adapter(&usbvision->i2c_adap);
242
243	PDEBUG(DBG_I2C, "i2c bus for %s registered", usbvision->i2c_adap.name);
244
245	/* Request the load of the i2c modules we need */
246	switch (usbvision_device_data[usbvision->DevModel].Codec) {
247	case CODEC_SAA7113:
248	case CODEC_SAA7111:
249		v4l2_i2c_new_probed_subdev(&usbvision->v4l2_dev,
250				&usbvision->i2c_adap, "saa7115",
251				"saa7115_auto", saa711x_addrs);
252		break;
253	}
254	if (usbvision_device_data[usbvision->DevModel].Tuner == 1) {
255		struct v4l2_subdev *sd;
256		enum v4l2_i2c_tuner_type type;
257		struct tuner_setup tun_setup;
258
259		sd = v4l2_i2c_new_probed_subdev(&usbvision->v4l2_dev,
260				&usbvision->i2c_adap, "tuner",
261				"tuner", v4l2_i2c_tuner_addrs(ADDRS_DEMOD));
262		/* depending on whether we found a demod or not, select
263		   the tuner type. */
264		type = sd ? ADDRS_TV_WITH_DEMOD : ADDRS_TV;
265
266		sd = v4l2_i2c_new_probed_subdev(&usbvision->v4l2_dev,
267				&usbvision->i2c_adap, "tuner",
268				"tuner", v4l2_i2c_tuner_addrs(type));
269
270		if (usbvision->tuner_type != -1) {
271			tun_setup.mode_mask = T_ANALOG_TV | T_RADIO;
272			tun_setup.type = usbvision->tuner_type;
273			tun_setup.addr = v4l2_i2c_subdev_addr(sd);
274			call_all(usbvision, tuner, s_type_addr, &tun_setup);
275		}
276	}
277
278	return 0;
279}
280
281int usbvision_i2c_unregister(struct usb_usbvision *usbvision)
282{
283
284	i2c_del_adapter(&(usbvision->i2c_adap));
285
286	PDEBUG(DBG_I2C,"i2c bus for %s unregistered", usbvision->i2c_adap.name);
287
288	return 0;
289}
290
291static int
292usbvision_i2c_read_max4(struct usb_usbvision *usbvision, unsigned char addr,
293		     char *buf, short len)
294{
295	int rc, retries;
296
297	for (retries = 5;;) {
298		rc = usbvision_write_reg(usbvision, USBVISION_SER_ADRS, addr);
299		if (rc < 0)
300			return rc;
301
302		/* Initiate byte read cycle                    */
303		/* USBVISION_SER_CONT <- d0-d2 n. of bytes to r/w */
304		/*                    d3 0=Wr 1=Rd             */
305		rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT,
306				      (len & 0x07) | 0x18);
307		if (rc < 0)
308			return rc;
309
310		/* Test for Busy and ACK */
311		do {
312			/* USBVISION_SER_CONT -> d4 == 0 busy */
313			rc = usbvision_read_reg(usbvision, USBVISION_SER_CONT);
314		} while (rc > 0 && ((rc & 0x10) != 0));	/* Retry while busy */
315		if (rc < 0)
316			return rc;
317
318		/* USBVISION_SER_CONT -> d5 == 1 Not ack */
319		if ((rc & 0x20) == 0)	/* Ack? */
320			break;
321
322		/* I2C abort */
323		rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT, 0x00);
324		if (rc < 0)
325			return rc;
326
327		if (--retries < 0)
328			return -1;
329	}
330
331	switch (len) {
332	case 4:
333		buf[3] = usbvision_read_reg(usbvision, USBVISION_SER_DAT4);
334	case 3:
335		buf[2] = usbvision_read_reg(usbvision, USBVISION_SER_DAT3);
336	case 2:
337		buf[1] = usbvision_read_reg(usbvision, USBVISION_SER_DAT2);
338	case 1:
339		buf[0] = usbvision_read_reg(usbvision, USBVISION_SER_DAT1);
340		break;
341	default:
342		printk(KERN_ERR
343		       "usbvision_i2c_read_max4: buffer length > 4\n");
344	}
345
346	if (i2c_debug & DBG_I2C) {
347		int idx;
348		for (idx = 0; idx < len; idx++) {
349			PDEBUG(DBG_I2C,"read %x from address %x", (unsigned char)buf[idx], addr);
350		}
351	}
352	return len;
353}
354
355
356static int usbvision_i2c_write_max4(struct usb_usbvision *usbvision,
357				 unsigned char addr, const char *buf,
358				 short len)
359{
360	int rc, retries;
361	int i;
362	unsigned char value[6];
363	unsigned char ser_cont;
364
365	ser_cont = (len & 0x07) | 0x10;
366
367	value[0] = addr;
368	value[1] = ser_cont;
369	for (i = 0; i < len; i++)
370		value[i + 2] = buf[i];
371
372	for (retries = 5;;) {
373		rc = usb_control_msg(usbvision->dev,
374				     usb_sndctrlpipe(usbvision->dev, 1),
375				     USBVISION_OP_CODE,
376				     USB_DIR_OUT | USB_TYPE_VENDOR |
377				     USB_RECIP_ENDPOINT, 0,
378				     (__u16) USBVISION_SER_ADRS, value,
379				     len + 2, HZ);
380
381		if (rc < 0)
382			return rc;
383
384		rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT,
385				      (len & 0x07) | 0x10);
386		if (rc < 0)
387			return rc;
388
389		/* Test for Busy and ACK */
390		do {
391			rc = usbvision_read_reg(usbvision, USBVISION_SER_CONT);
392		} while (rc > 0 && ((rc & 0x10) != 0));	/* Retry while busy */
393		if (rc < 0)
394			return rc;
395
396		if ((rc & 0x20) == 0)	/* Ack? */
397			break;
398
399		/* I2C abort */
400		usbvision_write_reg(usbvision, USBVISION_SER_CONT, 0x00);
401
402		if (--retries < 0)
403			return -1;
404
405	}
406
407	if (i2c_debug & DBG_I2C) {
408		int idx;
409		for (idx = 0; idx < len; idx++) {
410			PDEBUG(DBG_I2C,"wrote %x at address %x", (unsigned char)buf[idx], addr);
411		}
412	}
413	return len;
414}
415
416static int usbvision_i2c_write(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
417			    short len)
418{
419	char *bufPtr = buf;
420	int retval;
421	int wrcount = 0;
422	int count;
423	int maxLen = 4;
424
425	while (len > 0) {
426		count = (len > maxLen) ? maxLen : len;
427		retval = usbvision_i2c_write_max4(usbvision, addr, bufPtr, count);
428		if (retval > 0) {
429			len -= count;
430			bufPtr += count;
431			wrcount += count;
432		} else
433			return (retval < 0) ? retval : -EFAULT;
434	}
435	return wrcount;
436}
437
438static int usbvision_i2c_read(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
439			   short len)
440{
441	char temp[4];
442	int retval, i;
443	int rdcount = 0;
444	int count;
445
446	while (len > 0) {
447		count = (len > 3) ? 4 : len;
448		retval = usbvision_i2c_read_max4(usbvision, addr, temp, count);
449		if (retval > 0) {
450			for (i = 0; i < len; i++)
451				buf[rdcount + i] = temp[i];
452			len -= count;
453			rdcount += count;
454		} else
455			return (retval < 0) ? retval : -EFAULT;
456	}
457	return rdcount;
458}
459
460static struct i2c_adapter i2c_adap_template = {
461	.owner = THIS_MODULE,
462	.name              = "usbvision",
463};
464
465/*
466 * Overrides for Emacs so that we follow Linus's tabbing style.
467 * ---------------------------------------------------------------------------
468 * Local variables:
469 * c-basic-offset: 8
470 * End:
471 */
472