usbvision-i2c.c revision 1ff16c2091a557f8080eb62c087465a87e4330e9 
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 = 0;
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)) info("[%s:%d] " fmt, __PRETTY_FUNCTION__, __LINE__ , ## args)
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 = 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 = 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			err("died at extended address code, while writing");
120			return -EREMOTEIO;
121		}
122		add[0] = addr;
123		if (flags & I2C_M_RD) {
124			/* okay, now switch into reading mode */
125			addr |= 0x01;
126			ret = try_read_address(i2c_adap, addr, retries);
127			if (ret != 1) {
128				err("died at extended address code, while reading");
129				return -EREMOTEIO;
130			}
131		}
132
133	} else {		/* normal 7bit address  */
134		addr = (msg->addr << 1);
135		if (flags & I2C_M_RD)
136			addr |= 1;
137		if (flags & I2C_M_REV_DIR_ADDR)
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;
160
161	usbvision = i2c_get_adapdata(i2c_adap);
162	for (i = 0; i < num; i++) {
163		pmsg = &msgs[i];
164		ret = usb_find_address(i2c_adap, pmsg, i2c_adap->retries, &addr);
165		if (ret != 0) {
166			PDEBUG(DBG_I2C,"got NAK from device, message #%d", i);
167			return (ret < 0) ? ret : -EREMOTEIO;
168		}
169
170		if (pmsg->flags & I2C_M_RD) {
171			/* read bytes into buffer */
172			ret = (usbvision_i2c_read(usbvision, addr, pmsg->buf, pmsg->len));
173			if (ret < pmsg->len) {
174				return (ret < 0) ? ret : -EREMOTEIO;
175			}
176		} else {
177			/* write bytes from buffer */
178			ret = (usbvision_i2c_write(usbvision, addr, pmsg->buf, pmsg->len));
179			if (ret < pmsg->len) {
180				return (ret < 0) ? ret : -EREMOTEIO;
181			}
182		}
183	}
184	return num;
185}
186
187static int algo_control(struct i2c_adapter *adapter, unsigned int cmd, unsigned long arg)
188{
189	return 0;
190}
191
192static u32 functionality(struct i2c_adapter *adap)
193{
194	return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR | I2C_FUNC_PROTOCOL_MANGLING;
195}
196
197
198/* -----exported algorithm data: -------------------------------------	*/
199
200static struct i2c_algorithm usbvision_algo = {
201	.master_xfer   = usbvision_i2c_xfer,
202	.smbus_xfer    = NULL,
203	.algo_control  = algo_control,
204	.functionality = functionality,
205};
206
207
208/* ----------------------------------------------------------------------- */
209/* usbvision specific I2C functions                                        */
210/* ----------------------------------------------------------------------- */
211static struct i2c_adapter i2c_adap_template;
212static struct i2c_client i2c_client_template;
213
214int usbvision_i2c_register(struct usb_usbvision *usbvision)
215{
216	int ret;
217
218	usbvision->i2c_adap = i2c_adap_template;
219	usbvision->i2c_adap.dev.parent = &usbvision->dev->dev;
220
221	PDEBUG(DBG_I2C, "I2C   debugging is enabled [i2c]");
222
223	sprintf(usbvision->i2c_adap.name + strlen(usbvision->i2c_adap.name),
224		" #%d", usbvision->vdev->minor & 0x1f);
225	PDEBUG(DBG_I2C,"I2C Registering adaptername: %s", usbvision->i2c_adap.name);
226	i2c_set_adapdata(&usbvision->i2c_adap,usbvision);
227	if ((ret = i2c_add_adapter(&usbvision->i2c_adap)) < 0) {
228		PDEBUG(DBG_I2C,"could not add I2C adapter %s", usbvision->i2c_adap.name);
229		return ret;
230	}
231
232	/* TODO: use i2c_client for eeprom detection as an example... */
233	usbvision->i2c_client = i2c_client_template;
234	usbvision->i2c_client.adapter = &usbvision->i2c_adap;
235
236	if (usbvision_write_reg(usbvision, USBVISION_SER_MODE, USBVISION_IIC_LRNACK) < 0) {
237		printk(KERN_ERR "usbvision_i2c_register: can't write reg\n");
238		return -EBUSY;
239	}
240
241#ifdef CONFIG_MODULES
242	/* Request the load of the i2c modules we need */
243	switch (usbvision_device_data[usbvision->DevModel].Codec) {
244	case CODEC_SAA7113:
245		request_module("saa7115");
246		break;
247	case CODEC_SAA7111:
248		request_module("saa7115");
249		break;
250	}
251	if (usbvision_device_data[usbvision->DevModel].Tuner == 1) {
252		request_module("tuner");
253	}
254#endif
255
256	return 0;
257}
258
259int usbvision_i2c_unregister(struct usb_usbvision *usbvision)
260{
261
262	i2c_del_adapter(&(usbvision->i2c_adap));
263
264	PDEBUG(DBG_I2C,"i2c bus for %s unregistered", usbvision->i2c_adap.name);
265
266	return 0;
267}
268
269void call_i2c_clients(struct usb_usbvision *usbvision, unsigned int cmd,
270		      void *arg)
271{
272	i2c_clients_command(&usbvision->i2c_adap, cmd, arg);
273}
274
275static int attach_inform(struct i2c_client *client)
276{
277	struct usb_usbvision *usbvision;
278
279	usbvision = i2c_get_adapdata(client->adapter);
280	switch (client->addr << 1) {
281		case 0x43:
282		case 0x4b:
283		{
284			struct tuner_setup tun_setup;
285
286			tun_setup.mode_mask = T_ANALOG_TV | T_RADIO;
287			tun_setup.type = TUNER_TDA9887;
288			tun_setup.addr = client->addr;
289
290			call_i2c_clients(usbvision, TUNER_SET_TYPE_ADDR, &tun_setup);
291
292			break;
293		}
294		case 0x42:
295			PDEBUG(DBG_I2C,"attach_inform: saa7114 detected.");
296			break;
297		case 0x4a:
298			PDEBUG(DBG_I2C,"attach_inform: saa7113 detected.");
299			break;
300		case 0x48:
301			PDEBUG(DBG_I2C,"attach_inform: saa7111 detected.");
302			break;
303		case 0xa0:
304			PDEBUG(DBG_I2C,"attach_inform: eeprom detected.");
305			break;
306
307		default:
308			{
309				struct tuner_setup tun_setup;
310
311				PDEBUG(DBG_I2C,"attach inform: detected I2C address %x", client->addr << 1);
312				usbvision->tuner_addr = client->addr;
313
314				if ((usbvision->have_tuner) && (usbvision->tuner_type != -1)) {
315					tun_setup.mode_mask = T_ANALOG_TV | T_RADIO;
316					tun_setup.type = usbvision->tuner_type;
317					tun_setup.addr = usbvision->tuner_addr;
318					call_i2c_clients(usbvision, TUNER_SET_TYPE_ADDR, &tun_setup);
319				}
320			}
321			break;
322	}
323	return 0;
324}
325
326static int detach_inform(struct i2c_client *client)
327{
328	struct usb_usbvision *usbvision;
329
330	usbvision = i2c_get_adapdata(client->adapter);
331
332	PDEBUG(DBG_I2C,"usbvision[%d] detaches %s", usbvision->nr, client->name);
333	return 0;
334}
335
336static int
337usbvision_i2c_read_max4(struct usb_usbvision *usbvision, unsigned char addr,
338		     char *buf, short len)
339{
340	int rc, retries;
341
342	for (retries = 5;;) {
343		rc = usbvision_write_reg(usbvision, USBVISION_SER_ADRS, addr);
344		if (rc < 0)
345			return rc;
346
347		/* Initiate byte read cycle                    */
348		/* USBVISION_SER_CONT <- d0-d2 n. of bytes to r/w */
349		/*                    d3 0=Wr 1=Rd             */
350		rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT,
351				      (len & 0x07) | 0x18);
352		if (rc < 0)
353			return rc;
354
355		/* Test for Busy and ACK */
356		do {
357			/* USBVISION_SER_CONT -> d4 == 0 busy */
358			rc = usbvision_read_reg(usbvision, USBVISION_SER_CONT);
359		} while (rc > 0 && ((rc & 0x10) != 0));	/* Retry while busy */
360		if (rc < 0)
361			return rc;
362
363		/* USBVISION_SER_CONT -> d5 == 1 Not ack */
364		if ((rc & 0x20) == 0)	/* Ack? */
365			break;
366
367		/* I2C abort */
368		rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT, 0x00);
369		if (rc < 0)
370			return rc;
371
372		if (--retries < 0)
373			return -1;
374	}
375
376	switch (len) {
377	case 4:
378		buf[3] = usbvision_read_reg(usbvision, USBVISION_SER_DAT4);
379	case 3:
380		buf[2] = usbvision_read_reg(usbvision, USBVISION_SER_DAT3);
381	case 2:
382		buf[1] = usbvision_read_reg(usbvision, USBVISION_SER_DAT2);
383	case 1:
384		buf[0] = usbvision_read_reg(usbvision, USBVISION_SER_DAT1);
385		break;
386	default:
387		printk(KERN_ERR
388		       "usbvision_i2c_read_max4: buffer length > 4\n");
389	}
390
391	if (i2c_debug & DBG_I2C) {
392		int idx;
393		for (idx = 0; idx < len; idx++) {
394			PDEBUG(DBG_I2C,"read %x from address %x", (unsigned char)buf[idx], addr);
395		}
396	}
397	return len;
398}
399
400
401static int usbvision_i2c_write_max4(struct usb_usbvision *usbvision,
402				 unsigned char addr, const char *buf,
403				 short len)
404{
405	int rc, retries;
406	int i;
407	unsigned char value[6];
408	unsigned char ser_cont;
409
410	ser_cont = (len & 0x07) | 0x10;
411
412	value[0] = addr;
413	value[1] = ser_cont;
414	for (i = 0; i < len; i++)
415		value[i + 2] = buf[i];
416
417	for (retries = 5;;) {
418		rc = usb_control_msg(usbvision->dev,
419				     usb_sndctrlpipe(usbvision->dev, 1),
420				     USBVISION_OP_CODE,
421				     USB_DIR_OUT | USB_TYPE_VENDOR |
422				     USB_RECIP_ENDPOINT, 0,
423				     (__u16) USBVISION_SER_ADRS, value,
424				     len + 2, HZ);
425
426		if (rc < 0)
427			return rc;
428
429		rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT,
430				      (len & 0x07) | 0x10);
431		if (rc < 0)
432			return rc;
433
434		/* Test for Busy and ACK */
435		do {
436			rc = usbvision_read_reg(usbvision, USBVISION_SER_CONT);
437		} while (rc > 0 && ((rc & 0x10) != 0));	/* Retry while busy */
438		if (rc < 0)
439			return rc;
440
441		if ((rc & 0x20) == 0)	/* Ack? */
442			break;
443
444		/* I2C abort */
445		usbvision_write_reg(usbvision, USBVISION_SER_CONT, 0x00);
446
447		if (--retries < 0)
448			return -1;
449
450	}
451
452	if (i2c_debug & DBG_I2C) {
453		int idx;
454		for (idx = 0; idx < len; idx++) {
455			PDEBUG(DBG_I2C,"wrote %x at address %x", (unsigned char)buf[idx], addr);
456		}
457	}
458	return len;
459}
460
461static int usbvision_i2c_write(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
462			    short len)
463{
464	char *bufPtr = buf;
465	int retval;
466	int wrcount = 0;
467	int count;
468	int maxLen = 4;
469
470	while (len > 0) {
471		count = (len > maxLen) ? maxLen : len;
472		retval = usbvision_i2c_write_max4(usbvision, addr, bufPtr, count);
473		if (retval > 0) {
474			len -= count;
475			bufPtr += count;
476			wrcount += count;
477		} else
478			return (retval < 0) ? retval : -EFAULT;
479	}
480	return wrcount;
481}
482
483static int usbvision_i2c_read(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
484			   short len)
485{
486	char temp[4];
487	int retval, i;
488	int rdcount = 0;
489	int count;
490
491	while (len > 0) {
492		count = (len > 3) ? 4 : len;
493		retval = usbvision_i2c_read_max4(usbvision, addr, temp, count);
494		if (retval > 0) {
495			for (i = 0; i < len; i++)
496				buf[rdcount + i] = temp[i];
497			len -= count;
498			rdcount += count;
499		} else
500			return (retval < 0) ? retval : -EFAULT;
501	}
502	return rdcount;
503}
504
505static struct i2c_adapter i2c_adap_template = {
506	.owner = THIS_MODULE,
507	.name              = "usbvision",
508	.id                = I2C_HW_B_BT848, /* FIXME */
509	.algo = &usbvision_algo,
510	.algo_data = NULL,
511	.client_register   = attach_inform,
512	.client_unregister = detach_inform,
513#ifdef I2C_ADAP_CLASS_TV_ANALOG
514	.class             = I2C_ADAP_CLASS_TV_ANALOG,
515#else
516	.class		   = I2C_CLASS_TV_ANALOG,
517#endif
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