usbvision-i2c.c revision c6330fb86fd0fed98b7e0d5792881a77b778fefc 
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)) \
50			printk(KERN_INFO KBUILD_MODNAME ":[%s:%d] " fmt, \
51				__func__, __LINE__ , ## args); \
52	}
53
54static int usbvision_i2c_write(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
55			    short len);
56static int usbvision_i2c_read(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
57			   short len);
58
59static inline int try_write_address(struct i2c_adapter *i2c_adap,
60				    unsigned char addr, int retries)
61{
62	struct usb_usbvision *usbvision;
63	int i, ret = -1;
64	char buf[4];
65
66	usbvision = (struct usb_usbvision *)i2c_get_adapdata(i2c_adap);
67	buf[0] = 0x00;
68	for (i = 0; i <= retries; i++) {
69		ret = (usbvision_i2c_write(usbvision, addr, buf, 1));
70		if (ret == 1)
71			break;	/* success! */
72		udelay(5);
73		if (i == retries)	/* no success */
74			break;
75		udelay(10);
76	}
77	if (i) {
78		PDEBUG(DBG_I2C,"Needed %d retries for address %#2x", i, addr);
79		PDEBUG(DBG_I2C,"Maybe there's no device at this address");
80	}
81	return ret;
82}
83
84static inline int try_read_address(struct i2c_adapter *i2c_adap,
85				   unsigned char addr, int retries)
86{
87	struct usb_usbvision *usbvision;
88	int i, ret = -1;
89	char buf[4];
90
91	usbvision = (struct usb_usbvision *)i2c_get_adapdata(i2c_adap);
92	for (i = 0; i <= retries; i++) {
93		ret = (usbvision_i2c_read(usbvision, addr, buf, 1));
94		if (ret == 1)
95			break;	/* success! */
96		udelay(5);
97		if (i == retries)	/* no success */
98			break;
99		udelay(10);
100	}
101	if (i) {
102		PDEBUG(DBG_I2C,"Needed %d retries for address %#2x", i, addr);
103		PDEBUG(DBG_I2C,"Maybe there's no device at this address");
104	}
105	return ret;
106}
107
108static inline int usb_find_address(struct i2c_adapter *i2c_adap,
109				   struct i2c_msg *msg, int retries,
110				   unsigned char *add)
111{
112	unsigned short flags = msg->flags;
113
114	unsigned char addr;
115	int ret;
116	if ((flags & I2C_M_TEN)) {
117		/* a ten bit address */
118		addr = 0xf0 | ((msg->addr >> 7) & 0x03);
119		/* try extended address code... */
120		ret = try_write_address(i2c_adap, addr, retries);
121		if (ret != 1) {
122			err("died at extended address code, while writing");
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				err("died at extended address code, while reading");
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;
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 * registering functions to load algorithms at runtime
205 */
206static int usbvision_i2c_usb_add_bus(struct i2c_adapter *adap)
207{
208	PDEBUG(DBG_I2C, "I2C   debugging is enabled [i2c]");
209	PDEBUG(DBG_I2C, "ALGO   debugging is enabled [i2c]");
210
211	/* register new adapter to i2c module... */
212
213	adap->algo = &usbvision_algo;
214
215	adap->timeout = 100;	/* default values, should       */
216	adap->retries = 3;	/* be replaced by defines       */
217
218	i2c_add_adapter(adap);
219
220	PDEBUG(DBG_I2C,"i2c bus for %s registered", adap->name);
221
222	return 0;
223}
224
225/* ----------------------------------------------------------------------- */
226/* usbvision specific I2C functions                                        */
227/* ----------------------------------------------------------------------- */
228static struct i2c_adapter i2c_adap_template;
229static struct i2c_client i2c_client_template;
230
231int usbvision_i2c_register(struct usb_usbvision *usbvision)
232{
233	memcpy(&usbvision->i2c_adap, &i2c_adap_template,
234	       sizeof(struct i2c_adapter));
235	memcpy(&usbvision->i2c_client, &i2c_client_template,
236	       sizeof(struct i2c_client));
237
238	sprintf(usbvision->i2c_adap.name + strlen(usbvision->i2c_adap.name),
239		" #%d", usbvision->vdev->num);
240	PDEBUG(DBG_I2C,"Adaptername: %s", usbvision->i2c_adap.name);
241	usbvision->i2c_adap.dev.parent = &usbvision->dev->dev;
242
243	i2c_set_adapdata(&usbvision->i2c_adap, usbvision);
244	i2c_set_clientdata(&usbvision->i2c_client, usbvision);
245
246	usbvision->i2c_client.adapter = &usbvision->i2c_adap;
247
248	if (usbvision_write_reg(usbvision, USBVISION_SER_MODE, USBVISION_IIC_LRNACK) < 0) {
249		printk(KERN_ERR "usbvision_register: can't write reg\n");
250		return -EBUSY;
251	}
252
253#ifdef CONFIG_MODULES
254	/* Request the load of the i2c modules we need */
255	switch (usbvision_device_data[usbvision->DevModel].Codec) {
256	case CODEC_SAA7113:
257		request_module("saa7115");
258		break;
259	case CODEC_SAA7111:
260		request_module("saa7115");
261		break;
262	}
263	if (usbvision_device_data[usbvision->DevModel].Tuner == 1) {
264		request_module("tuner");
265	}
266#endif
267
268	return usbvision_i2c_usb_add_bus(&usbvision->i2c_adap);
269}
270
271int usbvision_i2c_unregister(struct usb_usbvision *usbvision)
272{
273
274	i2c_del_adapter(&(usbvision->i2c_adap));
275
276	PDEBUG(DBG_I2C,"i2c bus for %s unregistered", usbvision->i2c_adap.name);
277
278	return 0;
279}
280
281void call_i2c_clients(struct usb_usbvision *usbvision, unsigned int cmd,
282		      void *arg)
283{
284	i2c_clients_command(&usbvision->i2c_adap, cmd, arg);
285}
286
287static int attach_inform(struct i2c_client *client)
288{
289	struct usb_usbvision *usbvision;
290
291	usbvision = (struct usb_usbvision *)i2c_get_adapdata(client->adapter);
292
293	switch (client->addr << 1) {
294		case 0x42 << 1:
295		case 0x43 << 1:
296		case 0x4a << 1:
297		case 0x4b << 1:
298			PDEBUG(DBG_I2C,"attach_inform: tda9887 detected.");
299			break;
300		case 0x42:
301			PDEBUG(DBG_I2C,"attach_inform: saa7114 detected.");
302			break;
303		case 0x4a:
304			PDEBUG(DBG_I2C,"attach_inform: saa7113 detected.");
305			break;
306		case 0x48:
307			PDEBUG(DBG_I2C,"attach_inform: saa7111 detected.");
308			break;
309		case 0xa0:
310			PDEBUG(DBG_I2C,"attach_inform: eeprom detected.");
311			break;
312
313		default:
314			{
315				struct tuner_setup tun_setup;
316
317				PDEBUG(DBG_I2C,"attach inform: detected I2C address %x", client->addr << 1);
318				usbvision->tuner_addr = client->addr;
319
320				if ((usbvision->have_tuner) && (usbvision->tuner_type != -1)) {
321					tun_setup.mode_mask = T_ANALOG_TV | T_RADIO;
322					tun_setup.type = usbvision->tuner_type;
323					tun_setup.addr = usbvision->tuner_addr;
324					call_i2c_clients(usbvision, TUNER_SET_TYPE_ADDR, &tun_setup);
325				}
326			}
327			break;
328	}
329	return 0;
330}
331
332static int detach_inform(struct i2c_client *client)
333{
334	struct usb_usbvision *usbvision;
335
336	usbvision = (struct usb_usbvision *)i2c_get_adapdata(client->adapter);
337
338	PDEBUG(DBG_I2C,"usbvision[%d] detaches %s", usbvision->nr, client->name);
339	return 0;
340}
341
342static int
343usbvision_i2c_read_max4(struct usb_usbvision *usbvision, unsigned char addr,
344		     char *buf, short len)
345{
346	int rc, retries;
347
348	for (retries = 5;;) {
349		rc = usbvision_write_reg(usbvision, USBVISION_SER_ADRS, addr);
350		if (rc < 0)
351			return rc;
352
353		/* Initiate byte read cycle                    */
354		/* USBVISION_SER_CONT <- d0-d2 n. of bytes to r/w */
355		/*                    d3 0=Wr 1=Rd             */
356		rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT,
357				      (len & 0x07) | 0x18);
358		if (rc < 0)
359			return rc;
360
361		/* Test for Busy and ACK */
362		do {
363			/* USBVISION_SER_CONT -> d4 == 0 busy */
364			rc = usbvision_read_reg(usbvision, USBVISION_SER_CONT);
365		} while (rc > 0 && ((rc & 0x10) != 0));	/* Retry while busy */
366		if (rc < 0)
367			return rc;
368
369		/* USBVISION_SER_CONT -> d5 == 1 Not ack */
370		if ((rc & 0x20) == 0)	/* Ack? */
371			break;
372
373		/* I2C abort */
374		rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT, 0x00);
375		if (rc < 0)
376			return rc;
377
378		if (--retries < 0)
379			return -1;
380	}
381
382	switch (len) {
383	case 4:
384		buf[3] = usbvision_read_reg(usbvision, USBVISION_SER_DAT4);
385	case 3:
386		buf[2] = usbvision_read_reg(usbvision, USBVISION_SER_DAT3);
387	case 2:
388		buf[1] = usbvision_read_reg(usbvision, USBVISION_SER_DAT2);
389	case 1:
390		buf[0] = usbvision_read_reg(usbvision, USBVISION_SER_DAT1);
391		break;
392	default:
393		printk(KERN_ERR
394		       "usbvision_i2c_read_max4: buffer length > 4\n");
395	}
396
397	if (i2c_debug & DBG_I2C) {
398		int idx;
399		for (idx = 0; idx < len; idx++) {
400			PDEBUG(DBG_I2C,"read %x from address %x", (unsigned char)buf[idx], addr);
401		}
402	}
403	return len;
404}
405
406
407static int usbvision_i2c_write_max4(struct usb_usbvision *usbvision,
408				 unsigned char addr, const char *buf,
409				 short len)
410{
411	int rc, retries;
412	int i;
413	unsigned char value[6];
414	unsigned char ser_cont;
415
416	ser_cont = (len & 0x07) | 0x10;
417
418	value[0] = addr;
419	value[1] = ser_cont;
420	for (i = 0; i < len; i++)
421		value[i + 2] = buf[i];
422
423	for (retries = 5;;) {
424		rc = usb_control_msg(usbvision->dev,
425				     usb_sndctrlpipe(usbvision->dev, 1),
426				     USBVISION_OP_CODE,
427				     USB_DIR_OUT | USB_TYPE_VENDOR |
428				     USB_RECIP_ENDPOINT, 0,
429				     (__u16) USBVISION_SER_ADRS, value,
430				     len + 2, HZ);
431
432		if (rc < 0)
433			return rc;
434
435		rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT,
436				      (len & 0x07) | 0x10);
437		if (rc < 0)
438			return rc;
439
440		/* Test for Busy and ACK */
441		do {
442			rc = usbvision_read_reg(usbvision, USBVISION_SER_CONT);
443		} while (rc > 0 && ((rc & 0x10) != 0));	/* Retry while busy */
444		if (rc < 0)
445			return rc;
446
447		if ((rc & 0x20) == 0)	/* Ack? */
448			break;
449
450		/* I2C abort */
451		usbvision_write_reg(usbvision, USBVISION_SER_CONT, 0x00);
452
453		if (--retries < 0)
454			return -1;
455
456	}
457
458	if (i2c_debug & DBG_I2C) {
459		int idx;
460		for (idx = 0; idx < len; idx++) {
461			PDEBUG(DBG_I2C,"wrote %x at address %x", (unsigned char)buf[idx], addr);
462		}
463	}
464	return len;
465}
466
467static int usbvision_i2c_write(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
468			    short len)
469{
470	char *bufPtr = buf;
471	int retval;
472	int wrcount = 0;
473	int count;
474	int maxLen = 4;
475
476	while (len > 0) {
477		count = (len > maxLen) ? maxLen : len;
478		retval = usbvision_i2c_write_max4(usbvision, addr, bufPtr, count);
479		if (retval > 0) {
480			len -= count;
481			bufPtr += count;
482			wrcount += count;
483		} else
484			return (retval < 0) ? retval : -EFAULT;
485	}
486	return wrcount;
487}
488
489static int usbvision_i2c_read(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
490			   short len)
491{
492	char temp[4];
493	int retval, i;
494	int rdcount = 0;
495	int count;
496
497	while (len > 0) {
498		count = (len > 3) ? 4 : len;
499		retval = usbvision_i2c_read_max4(usbvision, addr, temp, count);
500		if (retval > 0) {
501			for (i = 0; i < len; i++)
502				buf[rdcount + i] = temp[i];
503			len -= count;
504			rdcount += count;
505		} else
506			return (retval < 0) ? retval : -EFAULT;
507	}
508	return rdcount;
509}
510
511static struct i2c_adapter i2c_adap_template = {
512	.owner = THIS_MODULE,
513	.name              = "usbvision",
514	.id                = I2C_HW_B_BT848, /* FIXME */
515	.client_register   = attach_inform,
516	.client_unregister = detach_inform,
517	.class		   = I2C_CLASS_TV_ANALOG,
518};
519
520static struct i2c_client i2c_client_template = {
521	.name		= "usbvision internal",
522};
523
524/*
525 * Overrides for Emacs so that we follow Linus's tabbing style.
526 * ---------------------------------------------------------------------------
527 * Local variables:
528 * c-basic-offset: 8
529 * End:
530 */
531