1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Driver for the Conexant CX25821 PCIe bridge
5 * Copyright (C) 2009 Conexant Systems Inc.
6 * Authors <shu.lin@conexant.com>, <hiep.huynh@conexant.com>
7 * Based on Steven Toth <stoth@linuxtv.org> cx23885 driver
10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12 #include <linux/module.h>
13 #include <linux/i2c.h>
16 static unsigned int i2c_debug;
17 module_param(i2c_debug, int, 0644);
18 MODULE_PARM_DESC(i2c_debug, "enable debug messages [i2c]");
20 static unsigned int i2c_scan;
21 module_param(i2c_scan, int, 0444);
22 MODULE_PARM_DESC(i2c_scan, "scan i2c bus at insmod time");
24 #define dprintk(level, fmt, arg...) \
26 if (i2c_debug >= level) \
27 printk(KERN_DEBUG "%s/0: " fmt, dev->name, ##arg); \
30 #define I2C_WAIT_DELAY 32
31 #define I2C_WAIT_RETRY 64
33 #define I2C_EXTEND (1 << 3)
34 #define I2C_NOSTOP (1 << 4)
36 static inline int i2c_slave_did_ack(struct i2c_adapter *i2c_adap)
38 struct cx25821_i2c *bus = i2c_adap->algo_data;
39 struct cx25821_dev *dev = bus->dev;
40 return cx_read(bus->reg_stat) & 0x01;
43 static inline int i2c_is_busy(struct i2c_adapter *i2c_adap)
45 struct cx25821_i2c *bus = i2c_adap->algo_data;
46 struct cx25821_dev *dev = bus->dev;
47 return cx_read(bus->reg_stat) & 0x02 ? 1 : 0;
50 static int i2c_wait_done(struct i2c_adapter *i2c_adap)
54 for (count = 0; count < I2C_WAIT_RETRY; count++) {
55 if (!i2c_is_busy(i2c_adap))
57 udelay(I2C_WAIT_DELAY);
60 if (I2C_WAIT_RETRY == count)
66 static int i2c_sendbytes(struct i2c_adapter *i2c_adap,
67 const struct i2c_msg *msg, int joined_rlen)
69 struct cx25821_i2c *bus = i2c_adap->algo_data;
70 struct cx25821_dev *dev = bus->dev;
71 u32 wdata, addr, ctrl;
75 dprintk(1, "%s(msg->wlen=%d, nextmsg->rlen=%d)\n", __func__,
76 msg->len, joined_rlen);
78 dprintk(1, "%s(msg->len=%d)\n", __func__, msg->len);
80 /* Deal with i2c probe functions with zero payload */
82 cx_write(bus->reg_addr, msg->addr << 25);
83 cx_write(bus->reg_ctrl, bus->i2c_period | (1 << 2));
85 if (!i2c_wait_done(i2c_adap))
88 if (!i2c_slave_did_ack(i2c_adap))
91 dprintk(1, "%s(): returns 0\n", __func__);
95 /* dev, reg + first byte */
96 addr = (msg->addr << 25) | msg->buf[0];
99 ctrl = bus->i2c_period | (1 << 12) | (1 << 2);
102 ctrl |= I2C_NOSTOP | I2C_EXTEND;
103 else if (joined_rlen)
106 cx_write(bus->reg_addr, addr);
107 cx_write(bus->reg_wdata, wdata);
108 cx_write(bus->reg_ctrl, ctrl);
110 retval = i2c_wait_done(i2c_adap);
118 if (!(ctrl & I2C_NOSTOP))
122 for (cnt = 1; cnt < msg->len; cnt++) {
123 /* following bytes */
124 wdata = msg->buf[cnt];
125 ctrl = bus->i2c_period | (1 << 12) | (1 << 2);
127 if (cnt < msg->len - 1)
128 ctrl |= I2C_NOSTOP | I2C_EXTEND;
129 else if (joined_rlen)
132 cx_write(bus->reg_addr, addr);
133 cx_write(bus->reg_wdata, wdata);
134 cx_write(bus->reg_ctrl, ctrl);
136 retval = i2c_wait_done(i2c_adap);
144 dprintk(1, " %02x", msg->buf[cnt]);
145 if (!(ctrl & I2C_NOSTOP))
156 pr_err(" ERR: %d\n", retval);
160 static int i2c_readbytes(struct i2c_adapter *i2c_adap,
161 const struct i2c_msg *msg, int joined)
163 struct cx25821_i2c *bus = i2c_adap->algo_data;
164 struct cx25821_dev *dev = bus->dev;
168 if (i2c_debug && !joined)
169 dprintk(1, "6-%s(msg->len=%d)\n", __func__, msg->len);
171 /* Deal with i2c probe functions with zero payload */
173 cx_write(bus->reg_addr, msg->addr << 25);
174 cx_write(bus->reg_ctrl, bus->i2c_period | (1 << 2) | 1);
175 if (!i2c_wait_done(i2c_adap))
177 if (!i2c_slave_did_ack(i2c_adap))
180 dprintk(1, "%s(): returns 0\n", __func__);
188 dprintk(1, " <R %02x", (msg->addr << 1) + 1);
191 for (cnt = 0; cnt < msg->len; cnt++) {
193 ctrl = bus->i2c_period | (1 << 12) | (1 << 2) | 1;
195 if (cnt < msg->len - 1)
196 ctrl |= I2C_NOSTOP | I2C_EXTEND;
198 cx_write(bus->reg_addr, msg->addr << 25);
199 cx_write(bus->reg_ctrl, ctrl);
201 retval = i2c_wait_done(i2c_adap);
206 msg->buf[cnt] = cx_read(bus->reg_rdata) & 0xff;
209 dprintk(1, " %02x", msg->buf[cnt]);
210 if (!(ctrl & I2C_NOSTOP))
220 pr_err(" ERR: %d\n", retval);
224 static int i2c_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num)
226 struct cx25821_i2c *bus = i2c_adap->algo_data;
227 struct cx25821_dev *dev = bus->dev;
230 dprintk(1, "%s(num = %d)\n", __func__, num);
232 for (i = 0; i < num; i++) {
233 dprintk(1, "%s(num = %d) addr = 0x%02x len = 0x%x\n",
234 __func__, num, msgs[i].addr, msgs[i].len);
236 if (msgs[i].flags & I2C_M_RD) {
238 retval = i2c_readbytes(i2c_adap, &msgs[i], 0);
239 } else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) &&
240 msgs[i].addr == msgs[i + 1].addr) {
241 /* write then read from same address */
242 retval = i2c_sendbytes(i2c_adap, &msgs[i],
248 retval = i2c_readbytes(i2c_adap, &msgs[i], 1);
251 retval = i2c_sendbytes(i2c_adap, &msgs[i], 0);
264 static u32 cx25821_functionality(struct i2c_adapter *adap)
266 return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C | I2C_FUNC_SMBUS_WORD_DATA |
267 I2C_FUNC_SMBUS_READ_WORD_DATA | I2C_FUNC_SMBUS_WRITE_WORD_DATA;
270 static const struct i2c_algorithm cx25821_i2c_algo_template = {
271 .master_xfer = i2c_xfer,
272 .functionality = cx25821_functionality,
273 #ifdef NEED_ALGO_CONTROL
274 .algo_control = dummy_algo_control,
278 static const struct i2c_adapter cx25821_i2c_adap_template = {
280 .owner = THIS_MODULE,
281 .algo = &cx25821_i2c_algo_template,
284 static const struct i2c_client cx25821_i2c_client_template = {
285 .name = "cx25821 internal",
288 /* init + register i2c adapter */
289 int cx25821_i2c_register(struct cx25821_i2c *bus)
291 struct cx25821_dev *dev = bus->dev;
293 dprintk(1, "%s(bus = %d)\n", __func__, bus->nr);
295 bus->i2c_adap = cx25821_i2c_adap_template;
296 bus->i2c_client = cx25821_i2c_client_template;
297 bus->i2c_adap.dev.parent = &dev->pci->dev;
299 strscpy(bus->i2c_adap.name, bus->dev->name, sizeof(bus->i2c_adap.name));
301 bus->i2c_adap.algo_data = bus;
302 i2c_set_adapdata(&bus->i2c_adap, &dev->v4l2_dev);
303 i2c_add_adapter(&bus->i2c_adap);
305 bus->i2c_client.adapter = &bus->i2c_adap;
308 bus->i2c_client.addr = (0x88 >> 1);
313 int cx25821_i2c_unregister(struct cx25821_i2c *bus)
315 i2c_del_adapter(&bus->i2c_adap);
319 #if 0 /* Currently unused */
320 static void cx25821_av_clk(struct cx25821_dev *dev, int enable)
322 /* write 0 to bus 2 addr 0x144 via i2x_xfer() */
325 dprintk(1, "%s(enabled = %d)\n", __func__, enable);
336 msg.flags = I2C_M_TEN;
340 i2c_xfer(&dev->i2c_bus[0].i2c_adap, &msg, 1);
344 int cx25821_i2c_read(struct cx25821_i2c *bus, u16 reg_addr, int *value)
346 struct i2c_client *client = &bus->i2c_client;
348 u8 addr[2] = { 0, 0 };
349 u8 buf[4] = { 0, 0, 0, 0 };
351 struct i2c_msg msgs[2] = {
353 .addr = client->addr,
358 .addr = client->addr,
365 addr[0] = (reg_addr >> 8);
366 addr[1] = (reg_addr & 0xff);
370 i2c_xfer(client->adapter, msgs, 2);
372 v = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0];
378 int cx25821_i2c_write(struct cx25821_i2c *bus, u16 reg_addr, int value)
380 struct i2c_client *client = &bus->i2c_client;
382 u8 buf[6] = { 0, 0, 0, 0, 0, 0 };
384 struct i2c_msg msgs[1] = {
386 .addr = client->addr,
393 buf[0] = reg_addr >> 8;
394 buf[1] = reg_addr & 0xff;
395 buf[5] = (value >> 24) & 0xff;
396 buf[4] = (value >> 16) & 0xff;
397 buf[3] = (value >> 8) & 0xff;
398 buf[2] = value & 0xff;
402 retval = i2c_xfer(client->adapter, msgs, 1);