usbvision-i2c.c revision 4d6c871ac338a8d804a1139dade2a463614d3e34 
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	memcpy(&usbvision->i2c_adap, &i2c_adap_template,
215	       sizeof(struct i2c_adapter));
216
217	sprintf(usbvision->i2c_adap.name, "%s-%d-%s", i2c_adap_template.name,
218		usbvision->dev->bus->busnum, usbvision->dev->devpath);
219	PDEBUG(DBG_I2C,"Adaptername: %s", usbvision->i2c_adap.name);
220	usbvision->i2c_adap.dev.parent = &usbvision->dev->dev;
221
222	i2c_set_adapdata(&usbvision->i2c_adap, &usbvision->v4l2_dev);
223
224	if (usbvision_write_reg(usbvision, USBVISION_SER_MODE, USBVISION_IIC_LRNACK) < 0) {
225		printk(KERN_ERR "usbvision_register: can't write reg\n");
226		return -EBUSY;
227	}
228
229	PDEBUG(DBG_I2C, "I2C   debugging is enabled [i2c]");
230	PDEBUG(DBG_I2C, "ALGO   debugging is enabled [i2c]");
231
232	/* register new adapter to i2c module... */
233
234	usbvision->i2c_adap.algo = &usbvision_algo;
235
236	usbvision->i2c_adap.timeout = 100;	/* default values, should       */
237	usbvision->i2c_adap.retries = 3;	/* be replaced by defines       */
238
239	i2c_add_adapter(&usbvision->i2c_adap);
240
241	PDEBUG(DBG_I2C, "i2c bus for %s registered", usbvision->i2c_adap.name);
242
243	/* Request the load of the i2c modules we need */
244	switch (usbvision_device_data[usbvision->DevModel].Codec) {
245	case CODEC_SAA7113:
246	case CODEC_SAA7111:
247		/* Without this delay the detection of the saa711x is
248		   hit-and-miss. */
249		mdelay(10);
250		v4l2_i2c_new_subdev(&usbvision->v4l2_dev,
251				&usbvision->i2c_adap, "saa7115",
252				"saa7115_auto", 0, saa711x_addrs);
253		break;
254	}
255	if (usbvision_device_data[usbvision->DevModel].Tuner == 1) {
256		struct v4l2_subdev *sd;
257		enum v4l2_i2c_tuner_type type;
258		struct tuner_setup tun_setup;
259
260		sd = v4l2_i2c_new_subdev(&usbvision->v4l2_dev,
261				&usbvision->i2c_adap, "tuner",
262				"tuner", 0, v4l2_i2c_tuner_addrs(ADDRS_DEMOD));
263		/* depending on whether we found a demod or not, select
264		   the tuner type. */
265		type = sd ? ADDRS_TV_WITH_DEMOD : ADDRS_TV;
266
267		sd = v4l2_i2c_new_subdev(&usbvision->v4l2_dev,
268				&usbvision->i2c_adap, "tuner",
269				"tuner", 0, v4l2_i2c_tuner_addrs(type));
270
271		if (usbvision->tuner_type != -1) {
272			tun_setup.mode_mask = T_ANALOG_TV | T_RADIO;
273			tun_setup.type = usbvision->tuner_type;
274			tun_setup.addr = v4l2_i2c_subdev_addr(sd);
275			call_all(usbvision, tuner, s_type_addr, &tun_setup);
276		}
277	}
278
279	return 0;
280}
281
282int usbvision_i2c_unregister(struct usb_usbvision *usbvision)
283{
284
285	i2c_del_adapter(&(usbvision->i2c_adap));
286
287	PDEBUG(DBG_I2C,"i2c bus for %s unregistered", usbvision->i2c_adap.name);
288
289	return 0;
290}
291
292static int
293usbvision_i2c_read_max4(struct usb_usbvision *usbvision, unsigned char addr,
294		     char *buf, short len)
295{
296	int rc, retries;
297
298	for (retries = 5;;) {
299		rc = usbvision_write_reg(usbvision, USBVISION_SER_ADRS, addr);
300		if (rc < 0)
301			return rc;
302
303		/* Initiate byte read cycle                    */
304		/* USBVISION_SER_CONT <- d0-d2 n. of bytes to r/w */
305		/*                    d3 0=Wr 1=Rd             */
306		rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT,
307				      (len & 0x07) | 0x18);
308		if (rc < 0)
309			return rc;
310
311		/* Test for Busy and ACK */
312		do {
313			/* USBVISION_SER_CONT -> d4 == 0 busy */
314			rc = usbvision_read_reg(usbvision, USBVISION_SER_CONT);
315		} while (rc > 0 && ((rc & 0x10) != 0));	/* Retry while busy */
316		if (rc < 0)
317			return rc;
318
319		/* USBVISION_SER_CONT -> d5 == 1 Not ack */
320		if ((rc & 0x20) == 0)	/* Ack? */
321			break;
322
323		/* I2C abort */
324		rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT, 0x00);
325		if (rc < 0)
326			return rc;
327
328		if (--retries < 0)
329			return -1;
330	}
331
332	switch (len) {
333	case 4:
334		buf[3] = usbvision_read_reg(usbvision, USBVISION_SER_DAT4);
335	case 3:
336		buf[2] = usbvision_read_reg(usbvision, USBVISION_SER_DAT3);
337	case 2:
338		buf[1] = usbvision_read_reg(usbvision, USBVISION_SER_DAT2);
339	case 1:
340		buf[0] = usbvision_read_reg(usbvision, USBVISION_SER_DAT1);
341		break;
342	default:
343		printk(KERN_ERR
344		       "usbvision_i2c_read_max4: buffer length > 4\n");
345	}
346
347	if (i2c_debug & DBG_I2C) {
348		int idx;
349		for (idx = 0; idx < len; idx++) {
350			PDEBUG(DBG_I2C,"read %x from address %x", (unsigned char)buf[idx], addr);
351		}
352	}
353	return len;
354}
355
356
357static int usbvision_i2c_write_max4(struct usb_usbvision *usbvision,
358				 unsigned char addr, const char *buf,
359				 short len)
360{
361	int rc, retries;
362	int i;
363	unsigned char value[6];
364	unsigned char ser_cont;
365
366	ser_cont = (len & 0x07) | 0x10;
367
368	value[0] = addr;
369	value[1] = ser_cont;
370	for (i = 0; i < len; i++)
371		value[i + 2] = buf[i];
372
373	for (retries = 5;;) {
374		rc = usb_control_msg(usbvision->dev,
375				     usb_sndctrlpipe(usbvision->dev, 1),
376				     USBVISION_OP_CODE,
377				     USB_DIR_OUT | USB_TYPE_VENDOR |
378				     USB_RECIP_ENDPOINT, 0,
379				     (__u16) USBVISION_SER_ADRS, value,
380				     len + 2, HZ);
381
382		if (rc < 0)
383			return rc;
384
385		rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT,
386				      (len & 0x07) | 0x10);
387		if (rc < 0)
388			return rc;
389
390		/* Test for Busy and ACK */
391		do {
392			rc = usbvision_read_reg(usbvision, USBVISION_SER_CONT);
393		} while (rc > 0 && ((rc & 0x10) != 0));	/* Retry while busy */
394		if (rc < 0)
395			return rc;
396
397		if ((rc & 0x20) == 0)	/* Ack? */
398			break;
399
400		/* I2C abort */
401		usbvision_write_reg(usbvision, USBVISION_SER_CONT, 0x00);
402
403		if (--retries < 0)
404			return -1;
405
406	}
407
408	if (i2c_debug & DBG_I2C) {
409		int idx;
410		for (idx = 0; idx < len; idx++) {
411			PDEBUG(DBG_I2C,"wrote %x at address %x", (unsigned char)buf[idx], addr);
412		}
413	}
414	return len;
415}
416
417static int usbvision_i2c_write(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
418			    short len)
419{
420	char *bufPtr = buf;
421	int retval;
422	int wrcount = 0;
423	int count;
424	int maxLen = 4;
425
426	while (len > 0) {
427		count = (len > maxLen) ? maxLen : len;
428		retval = usbvision_i2c_write_max4(usbvision, addr, bufPtr, count);
429		if (retval > 0) {
430			len -= count;
431			bufPtr += count;
432			wrcount += count;
433		} else
434			return (retval < 0) ? retval : -EFAULT;
435	}
436	return wrcount;
437}
438
439static int usbvision_i2c_read(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
440			   short len)
441{
442	char temp[4];
443	int retval, i;
444	int rdcount = 0;
445	int count;
446
447	while (len > 0) {
448		count = (len > 3) ? 4 : len;
449		retval = usbvision_i2c_read_max4(usbvision, addr, temp, count);
450		if (retval > 0) {
451			for (i = 0; i < len; i++)
452				buf[rdcount + i] = temp[i];
453			len -= count;
454			rdcount += count;
455		} else
456			return (retval < 0) ? retval : -EFAULT;
457	}
458	return rdcount;
459}
460
461static struct i2c_adapter i2c_adap_template = {
462	.owner = THIS_MODULE,
463	.name              = "usbvision",
464};
465
466/*
467 * Overrides for Emacs so that we follow Linus's tabbing style.
468 * ---------------------------------------------------------------------------
469 * Local variables:
470 * c-basic-offset: 8
471 * End:
472 */
473