usbvision-i2c.c revision 1532a07042289d420f040f3bd4370cc106860003 
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/init.h>
31#include <asm/uaccess.h>
32#include <linux/ioport.h>
33#include <linux/errno.h>
34#include <linux/usb.h>
35#include <linux/i2c.h>
36#include "usbvision.h"
37
38#define DBG_I2C		1<<0
39
40static int i2c_debug;
41
42module_param (i2c_debug, int, 0644);			// debug_i2c_usb mode of the device driver
43MODULE_PARM_DESC(i2c_debug, "enable debug messages [i2c]");
44
45#define PDEBUG(level, fmt, args...) { \
46		if (i2c_debug & (level)) \
47			printk(KERN_INFO KBUILD_MODNAME ":[%s:%d] " fmt, \
48				__func__, __LINE__ , ## args); \
49	}
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			dev_err(&i2c_adap->dev,
120				"died at extended address code,	while writing\n");
121			return -EREMOTEIO;
122		}
123		add[0] = addr;
124		if (flags & I2C_M_RD) {
125			/* okay, now switch into reading mode */
126			addr |= 0x01;
127			ret = try_read_address(i2c_adap, addr, retries);
128			if (ret != 1) {
129				dev_err(&i2c_adap->dev,
130					"died at extended address code, while reading\n");
131				return -EREMOTEIO;
132			}
133		}
134
135	} else {		/* normal 7bit address  */
136		addr = (msg->addr << 1);
137		if (flags & I2C_M_RD)
138			addr |= 1;
139
140		add[0] = addr;
141		if (flags & I2C_M_RD)
142			ret = try_read_address(i2c_adap, addr, retries);
143		else
144			ret = try_write_address(i2c_adap, addr, retries);
145
146		if (ret != 1) {
147			return -EREMOTEIO;
148		}
149	}
150	return 0;
151}
152
153static int
154usbvision_i2c_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg msgs[], int num)
155{
156	struct i2c_msg *pmsg;
157	struct usb_usbvision *usbvision;
158	int i, ret;
159	unsigned char addr = 0;
160
161	usbvision = (struct usb_usbvision *)i2c_get_adapdata(i2c_adap);
162
163	for (i = 0; i < num; i++) {
164		pmsg = &msgs[i];
165		ret = usb_find_address(i2c_adap, pmsg, i2c_adap->retries, &addr);
166		if (ret != 0) {
167			PDEBUG(DBG_I2C,"got NAK from device, message #%d", i);
168			return (ret < 0) ? ret : -EREMOTEIO;
169		}
170
171		if (pmsg->flags & I2C_M_RD) {
172			/* read bytes into buffer */
173			ret = (usbvision_i2c_read(usbvision, addr, pmsg->buf, pmsg->len));
174			if (ret < pmsg->len) {
175				return (ret < 0) ? ret : -EREMOTEIO;
176			}
177		} else {
178			/* write bytes from buffer */
179			ret = (usbvision_i2c_write(usbvision, addr, pmsg->buf, pmsg->len));
180			if (ret < pmsg->len) {
181				return (ret < 0) ? ret : -EREMOTEIO;
182			}
183		}
184	}
185	return num;
186}
187
188static u32 functionality(struct i2c_adapter *adap)
189{
190	return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR;
191}
192
193/* -----exported algorithm data: -------------------------------------	*/
194
195static struct i2c_algorithm usbvision_algo = {
196	.master_xfer   = usbvision_i2c_xfer,
197	.smbus_xfer    = NULL,
198	.functionality = functionality,
199};
200
201
202/* ----------------------------------------------------------------------- */
203/* usbvision specific I2C functions                                        */
204/* ----------------------------------------------------------------------- */
205static struct i2c_adapter i2c_adap_template;
206
207int usbvision_i2c_register(struct usb_usbvision *usbvision)
208{
209	static unsigned short saa711x_addrs[] = {
210		0x4a >> 1, 0x48 >> 1,	/* SAA7111, SAA7111A and SAA7113 */
211		0x42 >> 1, 0x40 >> 1,	/* SAA7114, SAA7115 and SAA7118 */
212		I2C_CLIENT_END };
213
214	if (usbvision->registered_i2c)
215		return 0;
216
217	memcpy(&usbvision->i2c_adap, &i2c_adap_template,
218	       sizeof(struct i2c_adapter));
219
220	sprintf(usbvision->i2c_adap.name, "%s-%d-%s", i2c_adap_template.name,
221		usbvision->dev->bus->busnum, usbvision->dev->devpath);
222	PDEBUG(DBG_I2C,"Adaptername: %s", usbvision->i2c_adap.name);
223	usbvision->i2c_adap.dev.parent = &usbvision->dev->dev;
224
225	i2c_set_adapdata(&usbvision->i2c_adap, &usbvision->v4l2_dev);
226
227	if (usbvision_write_reg(usbvision, USBVISION_SER_MODE, USBVISION_IIC_LRNACK) < 0) {
228		printk(KERN_ERR "usbvision_register: can't write reg\n");
229		return -EBUSY;
230	}
231
232	PDEBUG(DBG_I2C, "I2C   debugging is enabled [i2c]");
233	PDEBUG(DBG_I2C, "ALGO   debugging is enabled [i2c]");
234
235	/* register new adapter to i2c module... */
236
237	usbvision->i2c_adap.algo = &usbvision_algo;
238
239	usbvision->i2c_adap.timeout = 100;	/* default values, should       */
240	usbvision->i2c_adap.retries = 3;	/* be replaced by defines       */
241
242	i2c_add_adapter(&usbvision->i2c_adap);
243
244	PDEBUG(DBG_I2C, "i2c bus for %s registered", usbvision->i2c_adap.name);
245
246	/* Request the load of the i2c modules we need */
247	switch (usbvision_device_data[usbvision->DevModel].Codec) {
248	case CODEC_SAA7113:
249	case CODEC_SAA7111:
250		/* Without this delay the detection of the saa711x is
251		   hit-and-miss. */
252		mdelay(10);
253		v4l2_i2c_new_subdev(&usbvision->v4l2_dev,
254				&usbvision->i2c_adap, NULL,
255				"saa7115_auto", 0, saa711x_addrs);
256		break;
257	}
258	if (usbvision_device_data[usbvision->DevModel].Tuner == 1) {
259		struct v4l2_subdev *sd;
260		enum v4l2_i2c_tuner_type type;
261		struct tuner_setup tun_setup;
262
263		sd = v4l2_i2c_new_subdev(&usbvision->v4l2_dev,
264				&usbvision->i2c_adap, NULL,
265				"tuner", 0, v4l2_i2c_tuner_addrs(ADDRS_DEMOD));
266		/* depending on whether we found a demod or not, select
267		   the tuner type. */
268		type = sd ? ADDRS_TV_WITH_DEMOD : ADDRS_TV;
269
270		sd = v4l2_i2c_new_subdev(&usbvision->v4l2_dev,
271				&usbvision->i2c_adap, NULL,
272				"tuner", 0, v4l2_i2c_tuner_addrs(type));
273
274		if (sd == NULL)
275			return -ENODEV;
276		if (usbvision->tuner_type != -1) {
277			tun_setup.mode_mask = T_ANALOG_TV | T_RADIO;
278			tun_setup.type = usbvision->tuner_type;
279			tun_setup.addr = v4l2_i2c_subdev_addr(sd);
280			call_all(usbvision, tuner, s_type_addr, &tun_setup);
281		}
282	}
283	usbvision->registered_i2c = 1;
284
285	return 0;
286}
287
288int usbvision_i2c_unregister(struct usb_usbvision *usbvision)
289{
290	if (!usbvision->registered_i2c)
291		return 0;
292
293	i2c_del_adapter(&(usbvision->i2c_adap));
294	usbvision->registered_i2c = 0;
295
296	PDEBUG(DBG_I2C,"i2c bus for %s unregistered", usbvision->i2c_adap.name);
297
298	return 0;
299}
300
301static int
302usbvision_i2c_read_max4(struct usb_usbvision *usbvision, unsigned char addr,
303		     char *buf, short len)
304{
305	int rc, retries;
306
307	for (retries = 5;;) {
308		rc = usbvision_write_reg(usbvision, USBVISION_SER_ADRS, addr);
309		if (rc < 0)
310			return rc;
311
312		/* Initiate byte read cycle                    */
313		/* USBVISION_SER_CONT <- d0-d2 n. of bytes to r/w */
314		/*                    d3 0=Wr 1=Rd             */
315		rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT,
316				      (len & 0x07) | 0x18);
317		if (rc < 0)
318			return rc;
319
320		/* Test for Busy and ACK */
321		do {
322			/* USBVISION_SER_CONT -> d4 == 0 busy */
323			rc = usbvision_read_reg(usbvision, USBVISION_SER_CONT);
324		} while (rc > 0 && ((rc & 0x10) != 0));	/* Retry while busy */
325		if (rc < 0)
326			return rc;
327
328		/* USBVISION_SER_CONT -> d5 == 1 Not ack */
329		if ((rc & 0x20) == 0)	/* Ack? */
330			break;
331
332		/* I2C abort */
333		rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT, 0x00);
334		if (rc < 0)
335			return rc;
336
337		if (--retries < 0)
338			return -1;
339	}
340
341	switch (len) {
342	case 4:
343		buf[3] = usbvision_read_reg(usbvision, USBVISION_SER_DAT4);
344	case 3:
345		buf[2] = usbvision_read_reg(usbvision, USBVISION_SER_DAT3);
346	case 2:
347		buf[1] = usbvision_read_reg(usbvision, USBVISION_SER_DAT2);
348	case 1:
349		buf[0] = usbvision_read_reg(usbvision, USBVISION_SER_DAT1);
350		break;
351	default:
352		printk(KERN_ERR
353		       "usbvision_i2c_read_max4: buffer length > 4\n");
354	}
355
356	if (i2c_debug & DBG_I2C) {
357		int idx;
358		for (idx = 0; idx < len; idx++) {
359			PDEBUG(DBG_I2C,"read %x from address %x", (unsigned char)buf[idx], addr);
360		}
361	}
362	return len;
363}
364
365
366static int usbvision_i2c_write_max4(struct usb_usbvision *usbvision,
367				 unsigned char addr, const char *buf,
368				 short len)
369{
370	int rc, retries;
371	int i;
372	unsigned char value[6];
373	unsigned char ser_cont;
374
375	ser_cont = (len & 0x07) | 0x10;
376
377	value[0] = addr;
378	value[1] = ser_cont;
379	for (i = 0; i < len; i++)
380		value[i + 2] = buf[i];
381
382	for (retries = 5;;) {
383		rc = usb_control_msg(usbvision->dev,
384				     usb_sndctrlpipe(usbvision->dev, 1),
385				     USBVISION_OP_CODE,
386				     USB_DIR_OUT | USB_TYPE_VENDOR |
387				     USB_RECIP_ENDPOINT, 0,
388				     (__u16) USBVISION_SER_ADRS, value,
389				     len + 2, HZ);
390
391		if (rc < 0)
392			return rc;
393
394		rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT,
395				      (len & 0x07) | 0x10);
396		if (rc < 0)
397			return rc;
398
399		/* Test for Busy and ACK */
400		do {
401			rc = usbvision_read_reg(usbvision, USBVISION_SER_CONT);
402		} while (rc > 0 && ((rc & 0x10) != 0));	/* Retry while busy */
403		if (rc < 0)
404			return rc;
405
406		if ((rc & 0x20) == 0)	/* Ack? */
407			break;
408
409		/* I2C abort */
410		usbvision_write_reg(usbvision, USBVISION_SER_CONT, 0x00);
411
412		if (--retries < 0)
413			return -1;
414
415	}
416
417	if (i2c_debug & DBG_I2C) {
418		int idx;
419		for (idx = 0; idx < len; idx++) {
420			PDEBUG(DBG_I2C,"wrote %x at address %x", (unsigned char)buf[idx], addr);
421		}
422	}
423	return len;
424}
425
426static int usbvision_i2c_write(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
427			    short len)
428{
429	char *bufPtr = buf;
430	int retval;
431	int wrcount = 0;
432	int count;
433	int maxLen = 4;
434
435	while (len > 0) {
436		count = (len > maxLen) ? maxLen : len;
437		retval = usbvision_i2c_write_max4(usbvision, addr, bufPtr, count);
438		if (retval > 0) {
439			len -= count;
440			bufPtr += count;
441			wrcount += count;
442		} else
443			return (retval < 0) ? retval : -EFAULT;
444	}
445	return wrcount;
446}
447
448static int usbvision_i2c_read(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
449			   short len)
450{
451	char temp[4];
452	int retval, i;
453	int rdcount = 0;
454	int count;
455
456	while (len > 0) {
457		count = (len > 3) ? 4 : len;
458		retval = usbvision_i2c_read_max4(usbvision, addr, temp, count);
459		if (retval > 0) {
460			for (i = 0; i < len; i++)
461				buf[rdcount + i] = temp[i];
462			len -= count;
463			rdcount += count;
464		} else
465			return (retval < 0) ? retval : -EFAULT;
466	}
467	return rdcount;
468}
469
470static struct i2c_adapter i2c_adap_template = {
471	.owner = THIS_MODULE,
472	.name              = "usbvision",
473};
474
475/*
476 * Overrides for Emacs so that we follow Linus's tabbing style.
477 * ---------------------------------------------------------------------------
478 * Local variables:
479 * c-basic-offset: 8
480 * End:
481 */
482