usbvision-i2c.c revision be9ed5117d95cdc4e601f9da220ebeaaab131679 
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			dev_err(&i2c_adap->dev,
123				"died at extended address code,	while writing\n");
124			return -EREMOTEIO;
125		}
126		add[0] = addr;
127		if (flags & I2C_M_RD) {
128			/* okay, now switch into reading mode */
129			addr |= 0x01;
130			ret = try_read_address(i2c_adap, addr, retries);
131			if (ret != 1) {
132				dev_err(&i2c_adap->dev,
133					"died at extended address code, while reading\n");
134				return -EREMOTEIO;
135			}
136		}
137
138	} else {		/* normal 7bit address  */
139		addr = (msg->addr << 1);
140		if (flags & I2C_M_RD)
141			addr |= 1;
142
143		add[0] = addr;
144		if (flags & I2C_M_RD)
145			ret = try_read_address(i2c_adap, addr, retries);
146		else
147			ret = try_write_address(i2c_adap, addr, retries);
148
149		if (ret != 1) {
150			return -EREMOTEIO;
151		}
152	}
153	return 0;
154}
155
156static int
157usbvision_i2c_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg msgs[], int num)
158{
159	struct i2c_msg *pmsg;
160	struct usb_usbvision *usbvision;
161	int i, ret;
162	unsigned char addr = 0;
163
164	usbvision = (struct usb_usbvision *)i2c_get_adapdata(i2c_adap);
165
166	for (i = 0; i < num; i++) {
167		pmsg = &msgs[i];
168		ret = usb_find_address(i2c_adap, pmsg, i2c_adap->retries, &addr);
169		if (ret != 0) {
170			PDEBUG(DBG_I2C,"got NAK from device, message #%d", i);
171			return (ret < 0) ? ret : -EREMOTEIO;
172		}
173
174		if (pmsg->flags & I2C_M_RD) {
175			/* read bytes into buffer */
176			ret = (usbvision_i2c_read(usbvision, addr, pmsg->buf, pmsg->len));
177			if (ret < pmsg->len) {
178				return (ret < 0) ? ret : -EREMOTEIO;
179			}
180		} else {
181			/* write bytes from buffer */
182			ret = (usbvision_i2c_write(usbvision, addr, pmsg->buf, pmsg->len));
183			if (ret < pmsg->len) {
184				return (ret < 0) ? ret : -EREMOTEIO;
185			}
186		}
187	}
188	return num;
189}
190
191static u32 functionality(struct i2c_adapter *adap)
192{
193	return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR;
194}
195
196/* -----exported algorithm data: -------------------------------------	*/
197
198static struct i2c_algorithm usbvision_algo = {
199	.master_xfer   = usbvision_i2c_xfer,
200	.smbus_xfer    = NULL,
201	.functionality = functionality,
202};
203
204
205/*
206 * registering functions to load algorithms at runtime
207 */
208static int usbvision_i2c_usb_add_bus(struct i2c_adapter *adap)
209{
210	PDEBUG(DBG_I2C, "I2C   debugging is enabled [i2c]");
211	PDEBUG(DBG_I2C, "ALGO   debugging is enabled [i2c]");
212
213	/* register new adapter to i2c module... */
214
215	adap->algo = &usbvision_algo;
216
217	adap->timeout = 100;	/* default values, should       */
218	adap->retries = 3;	/* be replaced by defines       */
219
220	i2c_add_adapter(adap);
221
222	PDEBUG(DBG_I2C,"i2c bus for %s registered", adap->name);
223
224	return 0;
225}
226
227/* ----------------------------------------------------------------------- */
228/* usbvision specific I2C functions                                        */
229/* ----------------------------------------------------------------------- */
230static struct i2c_adapter i2c_adap_template;
231static struct i2c_client i2c_client_template;
232
233int usbvision_i2c_register(struct usb_usbvision *usbvision)
234{
235	memcpy(&usbvision->i2c_adap, &i2c_adap_template,
236	       sizeof(struct i2c_adapter));
237	memcpy(&usbvision->i2c_client, &i2c_client_template,
238	       sizeof(struct i2c_client));
239
240	sprintf(usbvision->i2c_adap.name + strlen(usbvision->i2c_adap.name),
241		" #%d", usbvision->vdev->num);
242	PDEBUG(DBG_I2C,"Adaptername: %s", usbvision->i2c_adap.name);
243	usbvision->i2c_adap.dev.parent = &usbvision->dev->dev;
244
245	i2c_set_adapdata(&usbvision->i2c_adap, usbvision);
246	i2c_set_clientdata(&usbvision->i2c_client, usbvision);
247
248	usbvision->i2c_client.adapter = &usbvision->i2c_adap;
249
250	if (usbvision_write_reg(usbvision, USBVISION_SER_MODE, USBVISION_IIC_LRNACK) < 0) {
251		printk(KERN_ERR "usbvision_register: can't write reg\n");
252		return -EBUSY;
253	}
254
255#ifdef CONFIG_MODULES
256	/* Request the load of the i2c modules we need */
257	switch (usbvision_device_data[usbvision->DevModel].Codec) {
258	case CODEC_SAA7113:
259		request_module("saa7115");
260		break;
261	case CODEC_SAA7111:
262		request_module("saa7115");
263		break;
264	}
265	if (usbvision_device_data[usbvision->DevModel].Tuner == 1) {
266		request_module("tuner");
267	}
268#endif
269
270	return usbvision_i2c_usb_add_bus(&usbvision->i2c_adap);
271}
272
273int usbvision_i2c_unregister(struct usb_usbvision *usbvision)
274{
275
276	i2c_del_adapter(&(usbvision->i2c_adap));
277
278	PDEBUG(DBG_I2C,"i2c bus for %s unregistered", usbvision->i2c_adap.name);
279
280	return 0;
281}
282
283void call_i2c_clients(struct usb_usbvision *usbvision, unsigned int cmd,
284		      void *arg)
285{
286	i2c_clients_command(&usbvision->i2c_adap, cmd, arg);
287}
288
289static int attach_inform(struct i2c_client *client)
290{
291	struct usb_usbvision *usbvision;
292
293	usbvision = (struct usb_usbvision *)i2c_get_adapdata(client->adapter);
294
295	switch (client->addr << 1) {
296		case 0x42 << 1:
297		case 0x43 << 1:
298		case 0x4a << 1:
299		case 0x4b << 1:
300			PDEBUG(DBG_I2C,"attach_inform: tda9887 detected.");
301			break;
302		case 0x42:
303			PDEBUG(DBG_I2C,"attach_inform: saa7114 detected.");
304			break;
305		case 0x4a:
306			PDEBUG(DBG_I2C,"attach_inform: saa7113 detected.");
307			break;
308		case 0x48:
309			PDEBUG(DBG_I2C,"attach_inform: saa7111 detected.");
310			break;
311		case 0xa0:
312			PDEBUG(DBG_I2C,"attach_inform: eeprom detected.");
313			break;
314
315		default:
316			{
317				struct tuner_setup tun_setup;
318
319				PDEBUG(DBG_I2C,"attach inform: detected I2C address %x", client->addr << 1);
320				usbvision->tuner_addr = client->addr;
321
322				if ((usbvision->have_tuner) && (usbvision->tuner_type != -1)) {
323					tun_setup.mode_mask = T_ANALOG_TV | T_RADIO;
324					tun_setup.type = usbvision->tuner_type;
325					tun_setup.addr = usbvision->tuner_addr;
326					call_i2c_clients(usbvision, TUNER_SET_TYPE_ADDR, &tun_setup);
327				}
328			}
329			break;
330	}
331	return 0;
332}
333
334static int detach_inform(struct i2c_client *client)
335{
336	struct usb_usbvision *usbvision;
337
338	usbvision = (struct usb_usbvision *)i2c_get_adapdata(client->adapter);
339
340	PDEBUG(DBG_I2C,"usbvision[%d] detaches %s", usbvision->nr, client->name);
341	return 0;
342}
343
344static int
345usbvision_i2c_read_max4(struct usb_usbvision *usbvision, unsigned char addr,
346		     char *buf, short len)
347{
348	int rc, retries;
349
350	for (retries = 5;;) {
351		rc = usbvision_write_reg(usbvision, USBVISION_SER_ADRS, addr);
352		if (rc < 0)
353			return rc;
354
355		/* Initiate byte read cycle                    */
356		/* USBVISION_SER_CONT <- d0-d2 n. of bytes to r/w */
357		/*                    d3 0=Wr 1=Rd             */
358		rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT,
359				      (len & 0x07) | 0x18);
360		if (rc < 0)
361			return rc;
362
363		/* Test for Busy and ACK */
364		do {
365			/* USBVISION_SER_CONT -> d4 == 0 busy */
366			rc = usbvision_read_reg(usbvision, USBVISION_SER_CONT);
367		} while (rc > 0 && ((rc & 0x10) != 0));	/* Retry while busy */
368		if (rc < 0)
369			return rc;
370
371		/* USBVISION_SER_CONT -> d5 == 1 Not ack */
372		if ((rc & 0x20) == 0)	/* Ack? */
373			break;
374
375		/* I2C abort */
376		rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT, 0x00);
377		if (rc < 0)
378			return rc;
379
380		if (--retries < 0)
381			return -1;
382	}
383
384	switch (len) {
385	case 4:
386		buf[3] = usbvision_read_reg(usbvision, USBVISION_SER_DAT4);
387	case 3:
388		buf[2] = usbvision_read_reg(usbvision, USBVISION_SER_DAT3);
389	case 2:
390		buf[1] = usbvision_read_reg(usbvision, USBVISION_SER_DAT2);
391	case 1:
392		buf[0] = usbvision_read_reg(usbvision, USBVISION_SER_DAT1);
393		break;
394	default:
395		printk(KERN_ERR
396		       "usbvision_i2c_read_max4: buffer length > 4\n");
397	}
398
399	if (i2c_debug & DBG_I2C) {
400		int idx;
401		for (idx = 0; idx < len; idx++) {
402			PDEBUG(DBG_I2C,"read %x from address %x", (unsigned char)buf[idx], addr);
403		}
404	}
405	return len;
406}
407
408
409static int usbvision_i2c_write_max4(struct usb_usbvision *usbvision,
410				 unsigned char addr, const char *buf,
411				 short len)
412{
413	int rc, retries;
414	int i;
415	unsigned char value[6];
416	unsigned char ser_cont;
417
418	ser_cont = (len & 0x07) | 0x10;
419
420	value[0] = addr;
421	value[1] = ser_cont;
422	for (i = 0; i < len; i++)
423		value[i + 2] = buf[i];
424
425	for (retries = 5;;) {
426		rc = usb_control_msg(usbvision->dev,
427				     usb_sndctrlpipe(usbvision->dev, 1),
428				     USBVISION_OP_CODE,
429				     USB_DIR_OUT | USB_TYPE_VENDOR |
430				     USB_RECIP_ENDPOINT, 0,
431				     (__u16) USBVISION_SER_ADRS, value,
432				     len + 2, HZ);
433
434		if (rc < 0)
435			return rc;
436
437		rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT,
438				      (len & 0x07) | 0x10);
439		if (rc < 0)
440			return rc;
441
442		/* Test for Busy and ACK */
443		do {
444			rc = usbvision_read_reg(usbvision, USBVISION_SER_CONT);
445		} while (rc > 0 && ((rc & 0x10) != 0));	/* Retry while busy */
446		if (rc < 0)
447			return rc;
448
449		if ((rc & 0x20) == 0)	/* Ack? */
450			break;
451
452		/* I2C abort */
453		usbvision_write_reg(usbvision, USBVISION_SER_CONT, 0x00);
454
455		if (--retries < 0)
456			return -1;
457
458	}
459
460	if (i2c_debug & DBG_I2C) {
461		int idx;
462		for (idx = 0; idx < len; idx++) {
463			PDEBUG(DBG_I2C,"wrote %x at address %x", (unsigned char)buf[idx], addr);
464		}
465	}
466	return len;
467}
468
469static int usbvision_i2c_write(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
470			    short len)
471{
472	char *bufPtr = buf;
473	int retval;
474	int wrcount = 0;
475	int count;
476	int maxLen = 4;
477
478	while (len > 0) {
479		count = (len > maxLen) ? maxLen : len;
480		retval = usbvision_i2c_write_max4(usbvision, addr, bufPtr, count);
481		if (retval > 0) {
482			len -= count;
483			bufPtr += count;
484			wrcount += count;
485		} else
486			return (retval < 0) ? retval : -EFAULT;
487	}
488	return wrcount;
489}
490
491static int usbvision_i2c_read(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
492			   short len)
493{
494	char temp[4];
495	int retval, i;
496	int rdcount = 0;
497	int count;
498
499	while (len > 0) {
500		count = (len > 3) ? 4 : len;
501		retval = usbvision_i2c_read_max4(usbvision, addr, temp, count);
502		if (retval > 0) {
503			for (i = 0; i < len; i++)
504				buf[rdcount + i] = temp[i];
505			len -= count;
506			rdcount += count;
507		} else
508			return (retval < 0) ? retval : -EFAULT;
509	}
510	return rdcount;
511}
512
513static struct i2c_adapter i2c_adap_template = {
514	.owner = THIS_MODULE,
515	.name              = "usbvision",
516	.id                = I2C_HW_B_BT848, /* FIXME */
517	.client_register   = attach_inform,
518	.client_unregister = detach_inform,
519	.class		   = I2C_CLASS_TV_ANALOG,
520};
521
522static struct i2c_client i2c_client_template = {
523	.name		= "usbvision internal",
524};
525
526/*
527 * Overrides for Emacs so that we follow Linus's tabbing style.
528 * ---------------------------------------------------------------------------
529 * Local variables:
530 * c-basic-offset: 8
531 * End:
532 */
533