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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Driver for the Conexant CX25821 PCIe bridge4 *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 driver8 */9 10#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt11 12#include <linux/module.h>13#include <linux/i2c.h>14#include "cx25821.h"15 16static unsigned int i2c_debug;17module_param(i2c_debug, int, 0644);18MODULE_PARM_DESC(i2c_debug, "enable debug messages [i2c]");19 20static unsigned int i2c_scan;21module_param(i2c_scan, int, 0444);22MODULE_PARM_DESC(i2c_scan, "scan i2c bus at insmod time");23 24#define dprintk(level, fmt, arg...) \25do { \26 if (i2c_debug >= level) \27 printk(KERN_DEBUG "%s/0: " fmt, dev->name, ##arg); \28} while (0)29 30#define I2C_WAIT_DELAY 3231#define I2C_WAIT_RETRY 6432 33#define I2C_EXTEND (1 << 3)34#define I2C_NOSTOP (1 << 4)35 36static inline int i2c_slave_did_ack(struct i2c_adapter *i2c_adap)37{38 struct cx25821_i2c *bus = i2c_adap->algo_data;39 struct cx25821_dev *dev = bus->dev;40 return cx_read(bus->reg_stat) & 0x01;41}42 43static inline int i2c_is_busy(struct i2c_adapter *i2c_adap)44{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;48}49 50static int i2c_wait_done(struct i2c_adapter *i2c_adap)51{52 int count;53 54 for (count = 0; count < I2C_WAIT_RETRY; count++) {55 if (!i2c_is_busy(i2c_adap))56 break;57 udelay(I2C_WAIT_DELAY);58 }59 60 if (I2C_WAIT_RETRY == count)61 return 0;62 63 return 1;64}65 66static int i2c_sendbytes(struct i2c_adapter *i2c_adap,67 const struct i2c_msg *msg, int joined_rlen)68{69 struct cx25821_i2c *bus = i2c_adap->algo_data;70 struct cx25821_dev *dev = bus->dev;71 u32 wdata, addr, ctrl;72 int retval, cnt;73 74 if (joined_rlen)75 dprintk(1, "%s(msg->wlen=%d, nextmsg->rlen=%d)\n", __func__,76 msg->len, joined_rlen);77 else78 dprintk(1, "%s(msg->len=%d)\n", __func__, msg->len);79 80 /* Deal with i2c probe functions with zero payload */81 if (msg->len == 0) {82 cx_write(bus->reg_addr, msg->addr << 25);83 cx_write(bus->reg_ctrl, bus->i2c_period | (1 << 2));84 85 if (!i2c_wait_done(i2c_adap))86 return -EIO;87 88 if (!i2c_slave_did_ack(i2c_adap))89 return -EIO;90 91 dprintk(1, "%s(): returns 0\n", __func__);92 return 0;93 }94 95 /* dev, reg + first byte */96 addr = (msg->addr << 25) | msg->buf[0];97 wdata = msg->buf[0];98 99 ctrl = bus->i2c_period | (1 << 12) | (1 << 2);100 101 if (msg->len > 1)102 ctrl |= I2C_NOSTOP | I2C_EXTEND;103 else if (joined_rlen)104 ctrl |= I2C_NOSTOP;105 106 cx_write(bus->reg_addr, addr);107 cx_write(bus->reg_wdata, wdata);108 cx_write(bus->reg_ctrl, ctrl);109 110 retval = i2c_wait_done(i2c_adap);111 if (retval < 0)112 goto err;113 114 if (retval == 0)115 goto eio;116 117 if (i2c_debug) {118 if (!(ctrl & I2C_NOSTOP))119 printk(" >\n");120 }121 122 for (cnt = 1; cnt < msg->len; cnt++) {123 /* following bytes */124 wdata = msg->buf[cnt];125 ctrl = bus->i2c_period | (1 << 12) | (1 << 2);126 127 if (cnt < msg->len - 1)128 ctrl |= I2C_NOSTOP | I2C_EXTEND;129 else if (joined_rlen)130 ctrl |= I2C_NOSTOP;131 132 cx_write(bus->reg_addr, addr);133 cx_write(bus->reg_wdata, wdata);134 cx_write(bus->reg_ctrl, ctrl);135 136 retval = i2c_wait_done(i2c_adap);137 if (retval < 0)138 goto err;139 140 if (retval == 0)141 goto eio;142 143 if (i2c_debug) {144 dprintk(1, " %02x", msg->buf[cnt]);145 if (!(ctrl & I2C_NOSTOP))146 dprintk(1, " >\n");147 }148 }149 150 return msg->len;151 152eio:153 retval = -EIO;154err:155 if (i2c_debug)156 pr_err(" ERR: %d\n", retval);157 return retval;158}159 160static int i2c_readbytes(struct i2c_adapter *i2c_adap,161 const struct i2c_msg *msg, int joined)162{163 struct cx25821_i2c *bus = i2c_adap->algo_data;164 struct cx25821_dev *dev = bus->dev;165 u32 ctrl, cnt;166 int retval;167 168 if (i2c_debug && !joined)169 dprintk(1, "6-%s(msg->len=%d)\n", __func__, msg->len);170 171 /* Deal with i2c probe functions with zero payload */172 if (msg->len == 0) {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))176 return -EIO;177 if (!i2c_slave_did_ack(i2c_adap))178 return -EIO;179 180 dprintk(1, "%s(): returns 0\n", __func__);181 return 0;182 }183 184 if (i2c_debug) {185 if (joined)186 dprintk(1, " R");187 else188 dprintk(1, " <R %02x", (msg->addr << 1) + 1);189 }190 191 for (cnt = 0; cnt < msg->len; cnt++) {192 193 ctrl = bus->i2c_period | (1 << 12) | (1 << 2) | 1;194 195 if (cnt < msg->len - 1)196 ctrl |= I2C_NOSTOP | I2C_EXTEND;197 198 cx_write(bus->reg_addr, msg->addr << 25);199 cx_write(bus->reg_ctrl, ctrl);200 201 retval = i2c_wait_done(i2c_adap);202 if (retval < 0)203 goto err;204 if (retval == 0)205 goto eio;206 msg->buf[cnt] = cx_read(bus->reg_rdata) & 0xff;207 208 if (i2c_debug) {209 dprintk(1, " %02x", msg->buf[cnt]);210 if (!(ctrl & I2C_NOSTOP))211 dprintk(1, " >\n");212 }213 }214 215 return msg->len;216eio:217 retval = -EIO;218err:219 if (i2c_debug)220 pr_err(" ERR: %d\n", retval);221 return retval;222}223 224static int i2c_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num)225{226 struct cx25821_i2c *bus = i2c_adap->algo_data;227 struct cx25821_dev *dev = bus->dev;228 int i, retval = 0;229 230 dprintk(1, "%s(num = %d)\n", __func__, num);231 232 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);235 236 if (msgs[i].flags & I2C_M_RD) {237 /* read */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],243 msgs[i + 1].len);244 245 if (retval < 0)246 goto err;247 i++;248 retval = i2c_readbytes(i2c_adap, &msgs[i], 1);249 } else {250 /* write */251 retval = i2c_sendbytes(i2c_adap, &msgs[i], 0);252 }253 254 if (retval < 0)255 goto err;256 }257 return num;258 259err:260 return retval;261}262 263 264static u32 cx25821_functionality(struct i2c_adapter *adap)265{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;268}269 270static const struct i2c_algorithm cx25821_i2c_algo_template = {271 .master_xfer = i2c_xfer,272 .functionality = cx25821_functionality,273#ifdef NEED_ALGO_CONTROL274 .algo_control = dummy_algo_control,275#endif276};277 278static const struct i2c_adapter cx25821_i2c_adap_template = {279 .name = "cx25821",280 .owner = THIS_MODULE,281 .algo = &cx25821_i2c_algo_template,282};283 284static const struct i2c_client cx25821_i2c_client_template = {285 .name = "cx25821 internal",286};287 288/* init + register i2c adapter */289int cx25821_i2c_register(struct cx25821_i2c *bus)290{291 struct cx25821_dev *dev = bus->dev;292 293 dprintk(1, "%s(bus = %d)\n", __func__, bus->nr);294 295 bus->i2c_adap = cx25821_i2c_adap_template;296 bus->i2c_client = cx25821_i2c_client_template;297 bus->i2c_adap.dev.parent = &dev->pci->dev;298 299 strscpy(bus->i2c_adap.name, bus->dev->name, sizeof(bus->i2c_adap.name));300 301 bus->i2c_adap.algo_data = bus;302 i2c_set_adapdata(&bus->i2c_adap, &dev->v4l2_dev);303 i2c_add_adapter(&bus->i2c_adap);304 305 bus->i2c_client.adapter = &bus->i2c_adap;306 307 /* set up the I2c */308 bus->i2c_client.addr = (0x88 >> 1);309 310 return bus->i2c_rc;311}312 313int cx25821_i2c_unregister(struct cx25821_i2c *bus)314{315 i2c_del_adapter(&bus->i2c_adap);316 return 0;317}318 319#if 0 /* Currently unused */320static void cx25821_av_clk(struct cx25821_dev *dev, int enable)321{322 /* write 0 to bus 2 addr 0x144 via i2x_xfer() */323 char buffer[3];324 struct i2c_msg msg;325 dprintk(1, "%s(enabled = %d)\n", __func__, enable);326 327 /* Register 0x144 */328 buffer[0] = 0x01;329 buffer[1] = 0x44;330 if (enable == 1)331 buffer[2] = 0x05;332 else333 buffer[2] = 0x00;334 335 msg.addr = 0x44;336 msg.flags = I2C_M_TEN;337 msg.len = 3;338 msg.buf = buffer;339 340 i2c_xfer(&dev->i2c_bus[0].i2c_adap, &msg, 1);341}342#endif343 344int cx25821_i2c_read(struct cx25821_i2c *bus, u16 reg_addr, int *value)345{346 struct i2c_client *client = &bus->i2c_client;347 int v = 0;348 u8 addr[2] = { 0, 0 };349 u8 buf[4] = { 0, 0, 0, 0 };350 351 struct i2c_msg msgs[2] = {352 {353 .addr = client->addr,354 .flags = 0,355 .len = 2,356 .buf = addr,357 }, {358 .addr = client->addr,359 .flags = I2C_M_RD,360 .len = 4,361 .buf = buf,362 }363 };364 365 addr[0] = (reg_addr >> 8);366 addr[1] = (reg_addr & 0xff);367 msgs[0].addr = 0x44;368 msgs[1].addr = 0x44;369 370 i2c_xfer(client->adapter, msgs, 2);371 372 v = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0];373 *value = v;374 375 return v;376}377 378int cx25821_i2c_write(struct cx25821_i2c *bus, u16 reg_addr, int value)379{380 struct i2c_client *client = &bus->i2c_client;381 int retval = 0;382 u8 buf[6] = { 0, 0, 0, 0, 0, 0 };383 384 struct i2c_msg msgs[1] = {385 {386 .addr = client->addr,387 .flags = 0,388 .len = 6,389 .buf = buf,390 }391 };392 393 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;399 client->flags = 0;400 msgs[0].addr = 0x44;401 402 retval = i2c_xfer(client->adapter, msgs, 1);403 404 return retval;405}406