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.
23 #include <linux/kernel.h>
24 #include <linux/module.h>
25 #include <linux/delay.h>
26 #include <linux/init.h>
27 #include <linux/uaccess.h>
28 #include <linux/ioport.h>
29 #include <linux/errno.h>
30 #include <linux/usb.h>
31 #include <linux/i2c.h>
32 #include "usbvision.h"
34 #define DBG_I2C (1 << 0)
38 module_param(i2c_debug, int, 0644); /* debug_i2c_usb mode of the device driver */
39 MODULE_PARM_DESC(i2c_debug, "enable debug messages [i2c]");
41 #define PDEBUG(level, fmt, args...) { \
42 if (i2c_debug & (level)) \
43 printk(KERN_INFO KBUILD_MODNAME ":[%s:%d] " fmt, \
44 __func__, __LINE__ , ## args); \
47 static int usbvision_i2c_write(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
49 static int usbvision_i2c_read(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
52 static inline int try_write_address(struct i2c_adapter *i2c_adap,
53 unsigned char addr, int retries)
55 struct usb_usbvision *usbvision;
59 usbvision = (struct usb_usbvision *)i2c_get_adapdata(i2c_adap);
61 for (i = 0; i <= retries; i++) {
62 ret = (usbvision_i2c_write(usbvision, addr, buf, 1));
66 if (i == retries) /* no success */
71 PDEBUG(DBG_I2C, "Needed %d retries for address %#2x", i, addr);
72 PDEBUG(DBG_I2C, "Maybe there's no device at this address");
77 static inline int try_read_address(struct i2c_adapter *i2c_adap,
78 unsigned char addr, int retries)
80 struct usb_usbvision *usbvision;
84 usbvision = (struct usb_usbvision *)i2c_get_adapdata(i2c_adap);
85 for (i = 0; i <= retries; i++) {
86 ret = (usbvision_i2c_read(usbvision, addr, buf, 1));
90 if (i == retries) /* no success */
95 PDEBUG(DBG_I2C, "Needed %d retries for address %#2x", i, addr);
96 PDEBUG(DBG_I2C, "Maybe there's no device at this address");
101 static inline int usb_find_address(struct i2c_adapter *i2c_adap,
102 struct i2c_msg *msg, int retries,
105 unsigned short flags = msg->flags;
110 addr = (msg->addr << 1);
111 if (flags & I2C_M_RD)
115 if (flags & I2C_M_RD)
116 ret = try_read_address(i2c_adap, addr, retries);
118 ret = try_write_address(i2c_adap, addr, retries);
127 usbvision_i2c_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg msgs[], int num)
129 struct i2c_msg *pmsg;
130 struct usb_usbvision *usbvision;
132 unsigned char addr = 0;
134 usbvision = (struct usb_usbvision *)i2c_get_adapdata(i2c_adap);
136 for (i = 0; i < num; i++) {
138 ret = usb_find_address(i2c_adap, pmsg, i2c_adap->retries, &addr);
140 PDEBUG(DBG_I2C, "got NAK from device, message #%d", i);
141 return (ret < 0) ? ret : -EREMOTEIO;
144 if (pmsg->flags & I2C_M_RD) {
145 /* read bytes into buffer */
146 ret = (usbvision_i2c_read(usbvision, addr, pmsg->buf, pmsg->len));
148 return (ret < 0) ? ret : -EREMOTEIO;
150 /* write bytes from buffer */
151 ret = (usbvision_i2c_write(usbvision, addr, pmsg->buf, pmsg->len));
153 return (ret < 0) ? ret : -EREMOTEIO;
159 static u32 functionality(struct i2c_adapter *adap)
161 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
164 /* -----exported algorithm data: ------------------------------------- */
166 static const struct i2c_algorithm usbvision_algo = {
167 .master_xfer = usbvision_i2c_xfer,
169 .functionality = functionality,
173 /* ----------------------------------------------------------------------- */
174 /* usbvision specific I2C functions */
175 /* ----------------------------------------------------------------------- */
176 static const struct i2c_adapter i2c_adap_template;
178 int usbvision_i2c_register(struct usb_usbvision *usbvision)
180 static unsigned short saa711x_addrs[] = {
181 0x4a >> 1, 0x48 >> 1, /* SAA7111, SAA7111A and SAA7113 */
182 0x42 >> 1, 0x40 >> 1, /* SAA7114, SAA7115 and SAA7118 */
185 if (usbvision->registered_i2c)
188 usbvision->i2c_adap = i2c_adap_template;
190 snprintf(usbvision->i2c_adap.name, sizeof(usbvision->i2c_adap.name),
192 usbvision->dev->bus->busnum, usbvision->dev->devpath);
193 PDEBUG(DBG_I2C, "Adaptername: %s", usbvision->i2c_adap.name);
194 usbvision->i2c_adap.dev.parent = &usbvision->dev->dev;
196 i2c_set_adapdata(&usbvision->i2c_adap, &usbvision->v4l2_dev);
198 if (usbvision_write_reg(usbvision, USBVISION_SER_MODE, USBVISION_IIC_LRNACK) < 0) {
199 printk(KERN_ERR "usbvision_i2c_register: can't write reg\n");
203 PDEBUG(DBG_I2C, "I2C debugging is enabled [i2c]");
204 PDEBUG(DBG_I2C, "ALGO debugging is enabled [i2c]");
206 /* register new adapter to i2c module... */
208 usbvision->i2c_adap.algo = &usbvision_algo;
210 usbvision->i2c_adap.timeout = 100; /* default values, should */
211 usbvision->i2c_adap.retries = 3; /* be replaced by defines */
213 i2c_add_adapter(&usbvision->i2c_adap);
215 PDEBUG(DBG_I2C, "i2c bus for %s registered", usbvision->i2c_adap.name);
217 /* Request the load of the i2c modules we need */
218 switch (usbvision_device_data[usbvision->dev_model].codec) {
221 /* Without this delay the detection of the saa711x is
224 v4l2_i2c_new_subdev(&usbvision->v4l2_dev,
225 &usbvision->i2c_adap,
226 "saa7115_auto", 0, saa711x_addrs);
229 if (usbvision_device_data[usbvision->dev_model].tuner == 1) {
230 struct v4l2_subdev *sd;
231 enum v4l2_i2c_tuner_type type;
232 struct tuner_setup tun_setup;
234 sd = v4l2_i2c_new_subdev(&usbvision->v4l2_dev,
235 &usbvision->i2c_adap,
236 "tuner", 0, v4l2_i2c_tuner_addrs(ADDRS_DEMOD));
237 /* depending on whether we found a demod or not, select
239 type = sd ? ADDRS_TV_WITH_DEMOD : ADDRS_TV;
241 sd = v4l2_i2c_new_subdev(&usbvision->v4l2_dev,
242 &usbvision->i2c_adap,
243 "tuner", 0, v4l2_i2c_tuner_addrs(type));
247 if (usbvision->tuner_type != -1) {
248 tun_setup.mode_mask = T_ANALOG_TV | T_RADIO;
249 tun_setup.type = usbvision->tuner_type;
250 tun_setup.addr = v4l2_i2c_subdev_addr(sd);
251 call_all(usbvision, tuner, s_type_addr, &tun_setup);
254 usbvision->registered_i2c = 1;
259 int usbvision_i2c_unregister(struct usb_usbvision *usbvision)
261 if (!usbvision->registered_i2c)
264 i2c_del_adapter(&(usbvision->i2c_adap));
265 usbvision->registered_i2c = 0;
267 PDEBUG(DBG_I2C, "i2c bus for %s unregistered", usbvision->i2c_adap.name);
273 usbvision_i2c_read_max4(struct usb_usbvision *usbvision, unsigned char addr,
274 char *buf, short len)
278 for (retries = 5;;) {
279 rc = usbvision_write_reg(usbvision, USBVISION_SER_ADRS, addr);
283 /* Initiate byte read cycle */
284 /* USBVISION_SER_CONT <- d0-d2 n. of bytes to r/w */
286 rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT,
287 (len & 0x07) | 0x18);
291 /* Test for Busy and ACK */
293 /* USBVISION_SER_CONT -> d4 == 0 busy */
294 rc = usbvision_read_reg(usbvision, USBVISION_SER_CONT);
295 } while (rc > 0 && ((rc & 0x10) != 0)); /* Retry while busy */
299 /* USBVISION_SER_CONT -> d5 == 1 Not ack */
300 if ((rc & 0x20) == 0) /* Ack? */
304 rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT, 0x00);
314 buf[3] = usbvision_read_reg(usbvision, USBVISION_SER_DAT4);
317 buf[2] = usbvision_read_reg(usbvision, USBVISION_SER_DAT3);
320 buf[1] = usbvision_read_reg(usbvision, USBVISION_SER_DAT2);
323 buf[0] = usbvision_read_reg(usbvision, USBVISION_SER_DAT1);
327 "usbvision_i2c_read_max4: buffer length > 4\n");
330 if (i2c_debug & DBG_I2C) {
333 for (idx = 0; idx < len; idx++)
334 PDEBUG(DBG_I2C, "read %x from address %x", (unsigned char)buf[idx], addr);
340 static int usbvision_i2c_write_max4(struct usb_usbvision *usbvision,
341 unsigned char addr, const char *buf,
346 unsigned char *value = usbvision->ctrl_urb_buffer;
347 unsigned char ser_cont;
349 ser_cont = (len & 0x07) | 0x10;
353 for (i = 0; i < len; i++)
354 value[i + 2] = buf[i];
356 for (retries = 5;;) {
357 rc = usb_control_msg(usbvision->dev,
358 usb_sndctrlpipe(usbvision->dev, 1),
360 USB_DIR_OUT | USB_TYPE_VENDOR |
361 USB_RECIP_ENDPOINT, 0,
362 (__u16) USBVISION_SER_ADRS, value,
368 rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT,
369 (len & 0x07) | 0x10);
373 /* Test for Busy and ACK */
375 rc = usbvision_read_reg(usbvision, USBVISION_SER_CONT);
376 } while (rc > 0 && ((rc & 0x10) != 0)); /* Retry while busy */
380 if ((rc & 0x20) == 0) /* Ack? */
384 usbvision_write_reg(usbvision, USBVISION_SER_CONT, 0x00);
391 if (i2c_debug & DBG_I2C) {
394 for (idx = 0; idx < len; idx++)
395 PDEBUG(DBG_I2C, "wrote %x at address %x", (unsigned char)buf[idx], addr);
400 static int usbvision_i2c_write(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
410 count = (len > max_len) ? max_len : len;
411 retval = usbvision_i2c_write_max4(usbvision, addr, buf_ptr, count);
417 return (retval < 0) ? retval : -EFAULT;
422 static int usbvision_i2c_read(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
431 count = (len > 3) ? 4 : len;
432 retval = usbvision_i2c_read_max4(usbvision, addr, temp, count);
434 for (i = 0; i < len; i++)
435 buf[rdcount + i] = temp[i];
439 return (retval < 0) ? retval : -EFAULT;
444 static const struct i2c_adapter i2c_adap_template = {
445 .owner = THIS_MODULE,