1 // SPDX-License-Identifier: GPL-2.0-or-later
4 * i2c algorithm for USB-I2C Bridges
6 * Copyright (c) 1999-2007 Joerg Heckenbach <joerg@heckenbach-aw.de>
7 * Dwaine Garden <dwainegarden@rogers.com>
9 * This module is part of usbvision driver project.
10 * Updates to driver completed by Dwaine P. Garden
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/delay.h>
17 #include <linux/init.h>
18 #include <linux/uaccess.h>
19 #include <linux/ioport.h>
20 #include <linux/errno.h>
21 #include <linux/usb.h>
22 #include <linux/i2c.h>
23 #include "usbvision.h"
25 #define DBG_I2C (1 << 0)
29 module_param(i2c_debug, int, 0644); /* debug_i2c_usb mode of the device driver */
30 MODULE_PARM_DESC(i2c_debug, "enable debug messages [i2c]");
32 #define PDEBUG(level, fmt, args...) { \
33 if (i2c_debug & (level)) \
34 printk(KERN_INFO KBUILD_MODNAME ":[%s:%d] " fmt, \
35 __func__, __LINE__ , ## args); \
38 static int usbvision_i2c_write(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
40 static int usbvision_i2c_read(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
43 static inline int try_write_address(struct i2c_adapter *i2c_adap,
44 unsigned char addr, int retries)
46 struct usb_usbvision *usbvision;
50 usbvision = (struct usb_usbvision *)i2c_get_adapdata(i2c_adap);
52 for (i = 0; i <= retries; i++) {
53 ret = (usbvision_i2c_write(usbvision, addr, buf, 1));
57 if (i == retries) /* no success */
62 PDEBUG(DBG_I2C, "Needed %d retries for address %#2x", i, addr);
63 PDEBUG(DBG_I2C, "Maybe there's no device at this address");
68 static inline int try_read_address(struct i2c_adapter *i2c_adap,
69 unsigned char addr, int retries)
71 struct usb_usbvision *usbvision;
75 usbvision = (struct usb_usbvision *)i2c_get_adapdata(i2c_adap);
76 for (i = 0; i <= retries; i++) {
77 ret = (usbvision_i2c_read(usbvision, addr, buf, 1));
81 if (i == retries) /* no success */
86 PDEBUG(DBG_I2C, "Needed %d retries for address %#2x", i, addr);
87 PDEBUG(DBG_I2C, "Maybe there's no device at this address");
92 static inline int usb_find_address(struct i2c_adapter *i2c_adap,
93 struct i2c_msg *msg, int retries,
96 unsigned short flags = msg->flags;
101 addr = (msg->addr << 1);
102 if (flags & I2C_M_RD)
106 if (flags & I2C_M_RD)
107 ret = try_read_address(i2c_adap, addr, retries);
109 ret = try_write_address(i2c_adap, addr, retries);
118 usbvision_i2c_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg msgs[], int num)
120 struct i2c_msg *pmsg;
121 struct usb_usbvision *usbvision;
123 unsigned char addr = 0;
125 usbvision = (struct usb_usbvision *)i2c_get_adapdata(i2c_adap);
127 for (i = 0; i < num; i++) {
129 ret = usb_find_address(i2c_adap, pmsg, i2c_adap->retries, &addr);
131 PDEBUG(DBG_I2C, "got NAK from device, message #%d", i);
132 return (ret < 0) ? ret : -EREMOTEIO;
135 if (pmsg->flags & I2C_M_RD) {
136 /* read bytes into buffer */
137 ret = (usbvision_i2c_read(usbvision, addr, pmsg->buf, pmsg->len));
139 return (ret < 0) ? ret : -EREMOTEIO;
141 /* write bytes from buffer */
142 ret = (usbvision_i2c_write(usbvision, addr, pmsg->buf, pmsg->len));
144 return (ret < 0) ? ret : -EREMOTEIO;
150 static u32 functionality(struct i2c_adapter *adap)
152 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
155 /* -----exported algorithm data: ------------------------------------- */
157 static const struct i2c_algorithm usbvision_algo = {
158 .master_xfer = usbvision_i2c_xfer,
160 .functionality = functionality,
164 /* ----------------------------------------------------------------------- */
165 /* usbvision specific I2C functions */
166 /* ----------------------------------------------------------------------- */
167 static const struct i2c_adapter i2c_adap_template;
169 int usbvision_i2c_register(struct usb_usbvision *usbvision)
171 static unsigned short saa711x_addrs[] = {
172 0x4a >> 1, 0x48 >> 1, /* SAA7111, SAA7111A and SAA7113 */
173 0x42 >> 1, 0x40 >> 1, /* SAA7114, SAA7115 and SAA7118 */
176 if (usbvision->registered_i2c)
179 usbvision->i2c_adap = i2c_adap_template;
181 snprintf(usbvision->i2c_adap.name, sizeof(usbvision->i2c_adap.name),
183 usbvision->dev->bus->busnum, usbvision->dev->devpath);
184 PDEBUG(DBG_I2C, "Adaptername: %s", usbvision->i2c_adap.name);
185 usbvision->i2c_adap.dev.parent = &usbvision->dev->dev;
187 i2c_set_adapdata(&usbvision->i2c_adap, &usbvision->v4l2_dev);
189 if (usbvision_write_reg(usbvision, USBVISION_SER_MODE, USBVISION_IIC_LRNACK) < 0) {
190 printk(KERN_ERR "usbvision_i2c_register: can't write reg\n");
194 PDEBUG(DBG_I2C, "I2C debugging is enabled [i2c]");
195 PDEBUG(DBG_I2C, "ALGO debugging is enabled [i2c]");
197 /* register new adapter to i2c module... */
199 usbvision->i2c_adap.algo = &usbvision_algo;
201 usbvision->i2c_adap.timeout = 100; /* default values, should */
202 usbvision->i2c_adap.retries = 3; /* be replaced by defines */
204 i2c_add_adapter(&usbvision->i2c_adap);
206 PDEBUG(DBG_I2C, "i2c bus for %s registered", usbvision->i2c_adap.name);
208 /* Request the load of the i2c modules we need */
209 switch (usbvision_device_data[usbvision->dev_model].codec) {
212 /* Without this delay the detection of the saa711x is
215 v4l2_i2c_new_subdev(&usbvision->v4l2_dev,
216 &usbvision->i2c_adap,
217 "saa7115_auto", 0, saa711x_addrs);
220 if (usbvision_device_data[usbvision->dev_model].tuner == 1) {
221 struct v4l2_subdev *sd;
222 enum v4l2_i2c_tuner_type type;
223 struct tuner_setup tun_setup;
225 sd = v4l2_i2c_new_subdev(&usbvision->v4l2_dev,
226 &usbvision->i2c_adap,
227 "tuner", 0, v4l2_i2c_tuner_addrs(ADDRS_DEMOD));
228 /* depending on whether we found a demod or not, select
230 type = sd ? ADDRS_TV_WITH_DEMOD : ADDRS_TV;
232 sd = v4l2_i2c_new_subdev(&usbvision->v4l2_dev,
233 &usbvision->i2c_adap,
234 "tuner", 0, v4l2_i2c_tuner_addrs(type));
238 if (usbvision->tuner_type != -1) {
239 tun_setup.mode_mask = T_ANALOG_TV | T_RADIO;
240 tun_setup.type = usbvision->tuner_type;
241 tun_setup.addr = v4l2_i2c_subdev_addr(sd);
242 call_all(usbvision, tuner, s_type_addr, &tun_setup);
245 usbvision->registered_i2c = 1;
250 int usbvision_i2c_unregister(struct usb_usbvision *usbvision)
252 if (!usbvision->registered_i2c)
255 i2c_del_adapter(&(usbvision->i2c_adap));
256 usbvision->registered_i2c = 0;
258 PDEBUG(DBG_I2C, "i2c bus for %s unregistered", usbvision->i2c_adap.name);
264 usbvision_i2c_read_max4(struct usb_usbvision *usbvision, unsigned char addr,
265 char *buf, short len)
269 for (retries = 5;;) {
270 rc = usbvision_write_reg(usbvision, USBVISION_SER_ADRS, addr);
274 /* Initiate byte read cycle */
275 /* USBVISION_SER_CONT <- d0-d2 n. of bytes to r/w */
277 rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT,
278 (len & 0x07) | 0x18);
282 /* Test for Busy and ACK */
284 /* USBVISION_SER_CONT -> d4 == 0 busy */
285 rc = usbvision_read_reg(usbvision, USBVISION_SER_CONT);
286 } while (rc > 0 && ((rc & 0x10) != 0)); /* Retry while busy */
290 /* USBVISION_SER_CONT -> d5 == 1 Not ack */
291 if ((rc & 0x20) == 0) /* Ack? */
295 rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT, 0x00);
305 buf[3] = usbvision_read_reg(usbvision, USBVISION_SER_DAT4);
308 buf[2] = usbvision_read_reg(usbvision, USBVISION_SER_DAT3);
311 buf[1] = usbvision_read_reg(usbvision, USBVISION_SER_DAT2);
314 buf[0] = usbvision_read_reg(usbvision, USBVISION_SER_DAT1);
318 "usbvision_i2c_read_max4: buffer length > 4\n");
321 if (i2c_debug & DBG_I2C) {
324 for (idx = 0; idx < len; idx++)
325 PDEBUG(DBG_I2C, "read %x from address %x", (unsigned char)buf[idx], addr);
331 static int usbvision_i2c_write_max4(struct usb_usbvision *usbvision,
332 unsigned char addr, const char *buf,
337 unsigned char *value = usbvision->ctrl_urb_buffer;
338 unsigned char ser_cont;
340 ser_cont = (len & 0x07) | 0x10;
344 for (i = 0; i < len; i++)
345 value[i + 2] = buf[i];
347 for (retries = 5;;) {
348 rc = usb_control_msg(usbvision->dev,
349 usb_sndctrlpipe(usbvision->dev, 1),
351 USB_DIR_OUT | USB_TYPE_VENDOR |
352 USB_RECIP_ENDPOINT, 0,
353 (__u16) USBVISION_SER_ADRS, value,
359 rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT,
360 (len & 0x07) | 0x10);
364 /* Test for Busy and ACK */
366 rc = usbvision_read_reg(usbvision, USBVISION_SER_CONT);
367 } while (rc > 0 && ((rc & 0x10) != 0)); /* Retry while busy */
371 if ((rc & 0x20) == 0) /* Ack? */
375 usbvision_write_reg(usbvision, USBVISION_SER_CONT, 0x00);
382 if (i2c_debug & DBG_I2C) {
385 for (idx = 0; idx < len; idx++)
386 PDEBUG(DBG_I2C, "wrote %x at address %x", (unsigned char)buf[idx], addr);
391 static int usbvision_i2c_write(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
401 count = (len > max_len) ? max_len : len;
402 retval = usbvision_i2c_write_max4(usbvision, addr, buf_ptr, count);
408 return (retval < 0) ? retval : -EFAULT;
413 static int usbvision_i2c_read(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
422 count = (len > 3) ? 4 : len;
423 retval = usbvision_i2c_read_max4(usbvision, addr, temp, count);
425 for (i = 0; i < len; i++)
426 buf[rdcount + i] = temp[i];
430 return (retval < 0) ? retval : -EFAULT;
435 static const struct i2c_adapter i2c_adap_template = {
436 .owner = THIS_MODULE,