3 * i2c algorithm for USB-I2C Bridges
5 * Copyright (c) 1999-2007 Joerg Heckenbach <joerg@heckenbach-aw.de>
6 * Dwaine Garden <dwainegarden@rogers.com>
8 * This module is part of usbvision driver project.
9 * Updates to driver completed by Dwaine P. Garden
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.
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.
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.
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"
42 module_param (i2c_debug, int, 0644); // debug_i2c_usb mode of the device driver
43 MODULE_PARM_DESC(i2c_debug, "enable debug messages [i2c]");
45 #define PDEBUG(level, fmt, args...) { \
46 if (i2c_debug & (level)) \
47 printk(KERN_INFO KBUILD_MODNAME ":[%s:%d] " fmt, \
48 __func__, __LINE__ , ## args); \
51 static int usbvision_i2c_write(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
53 static int usbvision_i2c_read(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
56 static inline int try_write_address(struct i2c_adapter *i2c_adap,
57 unsigned char addr, int retries)
59 struct usb_usbvision *usbvision;
63 usbvision = (struct usb_usbvision *)i2c_get_adapdata(i2c_adap);
65 for (i = 0; i <= retries; i++) {
66 ret = (usbvision_i2c_write(usbvision, addr, buf, 1));
70 if (i == retries) /* no success */
75 PDEBUG(DBG_I2C,"Needed %d retries for address %#2x", i, addr);
76 PDEBUG(DBG_I2C,"Maybe there's no device at this address");
81 static inline int try_read_address(struct i2c_adapter *i2c_adap,
82 unsigned char addr, int retries)
84 struct usb_usbvision *usbvision;
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));
94 if (i == retries) /* no success */
99 PDEBUG(DBG_I2C,"Needed %d retries for address %#2x", i, addr);
100 PDEBUG(DBG_I2C,"Maybe there's no device at this address");
105 static inline int usb_find_address(struct i2c_adapter *i2c_adap,
106 struct i2c_msg *msg, int retries,
109 unsigned short flags = msg->flags;
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);
119 dev_err(&i2c_adap->dev,
120 "died at extended address code, while writing\n");
124 if (flags & I2C_M_RD) {
125 /* okay, now switch into reading mode */
127 ret = try_read_address(i2c_adap, addr, retries);
129 dev_err(&i2c_adap->dev,
130 "died at extended address code, while reading\n");
135 } else { /* normal 7bit address */
136 addr = (msg->addr << 1);
137 if (flags & I2C_M_RD)
141 if (flags & I2C_M_RD)
142 ret = try_read_address(i2c_adap, addr, retries);
144 ret = try_write_address(i2c_adap, addr, retries);
154 usbvision_i2c_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg msgs[], int num)
156 struct i2c_msg *pmsg;
157 struct usb_usbvision *usbvision;
159 unsigned char addr = 0;
161 usbvision = (struct usb_usbvision *)i2c_get_adapdata(i2c_adap);
163 for (i = 0; i < num; i++) {
165 ret = usb_find_address(i2c_adap, pmsg, i2c_adap->retries, &addr);
167 PDEBUG(DBG_I2C,"got NAK from device, message #%d", i);
168 return (ret < 0) ? ret : -EREMOTEIO;
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;
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;
188 static u32 functionality(struct i2c_adapter *adap)
190 return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR;
193 /* -----exported algorithm data: ------------------------------------- */
195 static struct i2c_algorithm usbvision_algo = {
196 .master_xfer = usbvision_i2c_xfer,
198 .functionality = functionality,
202 /* ----------------------------------------------------------------------- */
203 /* usbvision specific I2C functions */
204 /* ----------------------------------------------------------------------- */
205 static struct i2c_adapter i2c_adap_template;
207 int usbvision_i2c_register(struct usb_usbvision *usbvision)
209 static unsigned short saa711x_addrs[] = {
210 0x4a >> 1, 0x48 >> 1, /* SAA7111, SAA7111A and SAA7113 */
211 0x42 >> 1, 0x40 >> 1, /* SAA7114, SAA7115 and SAA7118 */
214 if (usbvision->registered_i2c)
217 memcpy(&usbvision->i2c_adap, &i2c_adap_template,
218 sizeof(struct i2c_adapter));
220 sprintf(usbvision->i2c_adap.name, "%s-%d-%s", i2c_adap_template.name,
221 usbvision->dev->bus->busnum, usbvision->dev->devpath);
222 PDEBUG(DBG_I2C,"Adaptername: %s", usbvision->i2c_adap.name);
223 usbvision->i2c_adap.dev.parent = &usbvision->dev->dev;
225 i2c_set_adapdata(&usbvision->i2c_adap, &usbvision->v4l2_dev);
227 if (usbvision_write_reg(usbvision, USBVISION_SER_MODE, USBVISION_IIC_LRNACK) < 0) {
228 printk(KERN_ERR "usbvision_register: can't write reg\n");
232 PDEBUG(DBG_I2C, "I2C debugging is enabled [i2c]");
233 PDEBUG(DBG_I2C, "ALGO debugging is enabled [i2c]");
235 /* register new adapter to i2c module... */
237 usbvision->i2c_adap.algo = &usbvision_algo;
239 usbvision->i2c_adap.timeout = 100; /* default values, should */
240 usbvision->i2c_adap.retries = 3; /* be replaced by defines */
242 i2c_add_adapter(&usbvision->i2c_adap);
244 PDEBUG(DBG_I2C, "i2c bus for %s registered", usbvision->i2c_adap.name);
246 /* Request the load of the i2c modules we need */
247 switch (usbvision_device_data[usbvision->DevModel].Codec) {
250 /* Without this delay the detection of the saa711x is
253 v4l2_i2c_new_subdev(&usbvision->v4l2_dev,
254 &usbvision->i2c_adap,
255 "saa7115_auto", 0, saa711x_addrs);
258 if (usbvision_device_data[usbvision->DevModel].Tuner == 1) {
259 struct v4l2_subdev *sd;
260 enum v4l2_i2c_tuner_type type;
261 struct tuner_setup tun_setup;
263 sd = v4l2_i2c_new_subdev(&usbvision->v4l2_dev,
264 &usbvision->i2c_adap,
265 "tuner", 0, v4l2_i2c_tuner_addrs(ADDRS_DEMOD));
266 /* depending on whether we found a demod or not, select
268 type = sd ? ADDRS_TV_WITH_DEMOD : ADDRS_TV;
270 sd = v4l2_i2c_new_subdev(&usbvision->v4l2_dev,
271 &usbvision->i2c_adap,
272 "tuner", 0, v4l2_i2c_tuner_addrs(type));
276 if (usbvision->tuner_type != -1) {
277 tun_setup.mode_mask = T_ANALOG_TV | T_RADIO;
278 tun_setup.type = usbvision->tuner_type;
279 tun_setup.addr = v4l2_i2c_subdev_addr(sd);
280 call_all(usbvision, tuner, s_type_addr, &tun_setup);
283 usbvision->registered_i2c = 1;
288 int usbvision_i2c_unregister(struct usb_usbvision *usbvision)
290 if (!usbvision->registered_i2c)
293 i2c_del_adapter(&(usbvision->i2c_adap));
294 usbvision->registered_i2c = 0;
296 PDEBUG(DBG_I2C,"i2c bus for %s unregistered", usbvision->i2c_adap.name);
302 usbvision_i2c_read_max4(struct usb_usbvision *usbvision, unsigned char addr,
303 char *buf, short len)
307 for (retries = 5;;) {
308 rc = usbvision_write_reg(usbvision, USBVISION_SER_ADRS, addr);
312 /* Initiate byte read cycle */
313 /* USBVISION_SER_CONT <- d0-d2 n. of bytes to r/w */
315 rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT,
316 (len & 0x07) | 0x18);
320 /* Test for Busy and ACK */
322 /* USBVISION_SER_CONT -> d4 == 0 busy */
323 rc = usbvision_read_reg(usbvision, USBVISION_SER_CONT);
324 } while (rc > 0 && ((rc & 0x10) != 0)); /* Retry while busy */
328 /* USBVISION_SER_CONT -> d5 == 1 Not ack */
329 if ((rc & 0x20) == 0) /* Ack? */
333 rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT, 0x00);
343 buf[3] = usbvision_read_reg(usbvision, USBVISION_SER_DAT4);
345 buf[2] = usbvision_read_reg(usbvision, USBVISION_SER_DAT3);
347 buf[1] = usbvision_read_reg(usbvision, USBVISION_SER_DAT2);
349 buf[0] = usbvision_read_reg(usbvision, USBVISION_SER_DAT1);
353 "usbvision_i2c_read_max4: buffer length > 4\n");
356 if (i2c_debug & DBG_I2C) {
358 for (idx = 0; idx < len; idx++) {
359 PDEBUG(DBG_I2C,"read %x from address %x", (unsigned char)buf[idx], addr);
366 static int usbvision_i2c_write_max4(struct usb_usbvision *usbvision,
367 unsigned char addr, const char *buf,
372 unsigned char value[6];
373 unsigned char ser_cont;
375 ser_cont = (len & 0x07) | 0x10;
379 for (i = 0; i < len; i++)
380 value[i + 2] = buf[i];
382 for (retries = 5;;) {
383 rc = usb_control_msg(usbvision->dev,
384 usb_sndctrlpipe(usbvision->dev, 1),
386 USB_DIR_OUT | USB_TYPE_VENDOR |
387 USB_RECIP_ENDPOINT, 0,
388 (__u16) USBVISION_SER_ADRS, value,
394 rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT,
395 (len & 0x07) | 0x10);
399 /* Test for Busy and ACK */
401 rc = usbvision_read_reg(usbvision, USBVISION_SER_CONT);
402 } while (rc > 0 && ((rc & 0x10) != 0)); /* Retry while busy */
406 if ((rc & 0x20) == 0) /* Ack? */
410 usbvision_write_reg(usbvision, USBVISION_SER_CONT, 0x00);
417 if (i2c_debug & DBG_I2C) {
419 for (idx = 0; idx < len; idx++) {
420 PDEBUG(DBG_I2C,"wrote %x at address %x", (unsigned char)buf[idx], addr);
426 static int usbvision_i2c_write(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
436 count = (len > maxLen) ? maxLen : len;
437 retval = usbvision_i2c_write_max4(usbvision, addr, bufPtr, count);
443 return (retval < 0) ? retval : -EFAULT;
448 static int usbvision_i2c_read(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
457 count = (len > 3) ? 4 : len;
458 retval = usbvision_i2c_read_max4(usbvision, addr, temp, count);
460 for (i = 0; i < len; i++)
461 buf[rdcount + i] = temp[i];
465 return (retval < 0) ? retval : -EFAULT;
470 static struct i2c_adapter i2c_adap_template = {
471 .owner = THIS_MODULE,
476 * Overrides for Emacs so that we follow Linus's tabbing style.
477 * ---------------------------------------------------------------------------