usbvision-i2c.c revision 3153bd91bfe14b6b93aef5b6b7c9fc279eec60d9 
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 0x42 << 1:
282		case 0x43 << 1:
283		case 0x4a << 1:
284		case 0x4b << 1:
285		{
286			struct tuner_setup tun_setup;
287
288			tun_setup.mode_mask = T_ANALOG_TV | T_RADIO;
289			tun_setup.type = TUNER_TDA9887;
290			tun_setup.addr = client->addr;
291
292			call_i2c_clients(usbvision, TUNER_SET_TYPE_ADDR, &tun_setup);
293
294			break;
295		}
296		case 0x42:
297			PDEBUG(DBG_I2C,"attach_inform: saa7114 detected.");
298			break;
299		case 0x4a:
300			PDEBUG(DBG_I2C,"attach_inform: saa7113 detected.");
301			break;
302		case 0x48:
303			PDEBUG(DBG_I2C,"attach_inform: saa7111 detected.");
304			break;
305		case 0xa0:
306			PDEBUG(DBG_I2C,"attach_inform: eeprom detected.");
307			break;
308
309		default:
310			{
311				struct tuner_setup tun_setup;
312
313				PDEBUG(DBG_I2C,"attach inform: detected I2C address %x", client->addr << 1);
314				usbvision->tuner_addr = client->addr;
315
316				if ((usbvision->have_tuner) && (usbvision->tuner_type != -1)) {
317					tun_setup.mode_mask = T_ANALOG_TV | T_RADIO;
318					tun_setup.type = usbvision->tuner_type;
319					tun_setup.addr = usbvision->tuner_addr;
320					call_i2c_clients(usbvision, TUNER_SET_TYPE_ADDR, &tun_setup);
321				}
322			}
323			break;
324	}
325	return 0;
326}
327
328static int detach_inform(struct i2c_client *client)
329{
330	struct usb_usbvision *usbvision;
331
332	usbvision = i2c_get_adapdata(client->adapter);
333
334	PDEBUG(DBG_I2C,"usbvision[%d] detaches %s", usbvision->nr, client->name);
335	return 0;
336}
337
338static int
339usbvision_i2c_read_max4(struct usb_usbvision *usbvision, unsigned char addr,
340		     char *buf, short len)
341{
342	int rc, retries;
343
344	for (retries = 5;;) {
345		rc = usbvision_write_reg(usbvision, USBVISION_SER_ADRS, addr);
346		if (rc < 0)
347			return rc;
348
349		/* Initiate byte read cycle                    */
350		/* USBVISION_SER_CONT <- d0-d2 n. of bytes to r/w */
351		/*                    d3 0=Wr 1=Rd             */
352		rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT,
353				      (len & 0x07) | 0x18);
354		if (rc < 0)
355			return rc;
356
357		/* Test for Busy and ACK */
358		do {
359			/* USBVISION_SER_CONT -> d4 == 0 busy */
360			rc = usbvision_read_reg(usbvision, USBVISION_SER_CONT);
361		} while (rc > 0 && ((rc & 0x10) != 0));	/* Retry while busy */
362		if (rc < 0)
363			return rc;
364
365		/* USBVISION_SER_CONT -> d5 == 1 Not ack */
366		if ((rc & 0x20) == 0)	/* Ack? */
367			break;
368
369		/* I2C abort */
370		rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT, 0x00);
371		if (rc < 0)
372			return rc;
373
374		if (--retries < 0)
375			return -1;
376	}
377
378	switch (len) {
379	case 4:
380		buf[3] = usbvision_read_reg(usbvision, USBVISION_SER_DAT4);
381	case 3:
382		buf[2] = usbvision_read_reg(usbvision, USBVISION_SER_DAT3);
383	case 2:
384		buf[1] = usbvision_read_reg(usbvision, USBVISION_SER_DAT2);
385	case 1:
386		buf[0] = usbvision_read_reg(usbvision, USBVISION_SER_DAT1);
387		break;
388	default:
389		printk(KERN_ERR
390		       "usbvision_i2c_read_max4: buffer length > 4\n");
391	}
392
393	if (i2c_debug & DBG_I2C) {
394		int idx;
395		for (idx = 0; idx < len; idx++) {
396			PDEBUG(DBG_I2C,"read %x from address %x", (unsigned char)buf[idx], addr);
397		}
398	}
399	return len;
400}
401
402
403static int usbvision_i2c_write_max4(struct usb_usbvision *usbvision,
404				 unsigned char addr, const char *buf,
405				 short len)
406{
407	int rc, retries;
408	int i;
409	unsigned char value[6];
410	unsigned char ser_cont;
411
412	ser_cont = (len & 0x07) | 0x10;
413
414	value[0] = addr;
415	value[1] = ser_cont;
416	for (i = 0; i < len; i++)
417		value[i + 2] = buf[i];
418
419	for (retries = 5;;) {
420		rc = usb_control_msg(usbvision->dev,
421				     usb_sndctrlpipe(usbvision->dev, 1),
422				     USBVISION_OP_CODE,
423				     USB_DIR_OUT | USB_TYPE_VENDOR |
424				     USB_RECIP_ENDPOINT, 0,
425				     (__u16) USBVISION_SER_ADRS, value,
426				     len + 2, HZ);
427
428		if (rc < 0)
429			return rc;
430
431		rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT,
432				      (len & 0x07) | 0x10);
433		if (rc < 0)
434			return rc;
435
436		/* Test for Busy and ACK */
437		do {
438			rc = usbvision_read_reg(usbvision, USBVISION_SER_CONT);
439		} while (rc > 0 && ((rc & 0x10) != 0));	/* Retry while busy */
440		if (rc < 0)
441			return rc;
442
443		if ((rc & 0x20) == 0)	/* Ack? */
444			break;
445
446		/* I2C abort */
447		usbvision_write_reg(usbvision, USBVISION_SER_CONT, 0x00);
448
449		if (--retries < 0)
450			return -1;
451
452	}
453
454	if (i2c_debug & DBG_I2C) {
455		int idx;
456		for (idx = 0; idx < len; idx++) {
457			PDEBUG(DBG_I2C,"wrote %x at address %x", (unsigned char)buf[idx], addr);
458		}
459	}
460	return len;
461}
462
463static int usbvision_i2c_write(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
464			    short len)
465{
466	char *bufPtr = buf;
467	int retval;
468	int wrcount = 0;
469	int count;
470	int maxLen = 4;
471
472	while (len > 0) {
473		count = (len > maxLen) ? maxLen : len;
474		retval = usbvision_i2c_write_max4(usbvision, addr, bufPtr, count);
475		if (retval > 0) {
476			len -= count;
477			bufPtr += count;
478			wrcount += count;
479		} else
480			return (retval < 0) ? retval : -EFAULT;
481	}
482	return wrcount;
483}
484
485static int usbvision_i2c_read(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
486			   short len)
487{
488	char temp[4];
489	int retval, i;
490	int rdcount = 0;
491	int count;
492
493	while (len > 0) {
494		count = (len > 3) ? 4 : len;
495		retval = usbvision_i2c_read_max4(usbvision, addr, temp, count);
496		if (retval > 0) {
497			for (i = 0; i < len; i++)
498				buf[rdcount + i] = temp[i];
499			len -= count;
500			rdcount += count;
501		} else
502			return (retval < 0) ? retval : -EFAULT;
503	}
504	return rdcount;
505}
506
507static struct i2c_adapter i2c_adap_template = {
508	.owner = THIS_MODULE,
509	.name              = "usbvision",
510	.id                = I2C_HW_B_BT848, /* FIXME */
511	.algo = &usbvision_algo,
512	.algo_data = NULL,
513	.client_register   = attach_inform,
514	.client_unregister = detach_inform,
515#ifdef I2C_ADAP_CLASS_TV_ANALOG
516	.class             = I2C_ADAP_CLASS_TV_ANALOG,
517#else
518	.class		   = I2C_CLASS_TV_ANALOG,
519#endif
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