drivers/media/video/cx25821/cx25821-i2c.c

   1 /*
   2  *  Driver for the Conexant CX25821 PCIe bridge
   3  *
   4  *  Copyright (C) 2009 Conexant Systems Inc.
   5  *  Authors  <shu.lin@conexant.com>, <hiep.huynh@conexant.com>
   6  *      Based on Steven Toth <stoth@linuxtv.org> cx23885 driver
   7  *
   8  *  This program is free software; you can redistribute it and/or modify
   9  *  it under the terms of the GNU General Public License as published by
  10  *  the Free Software Foundation; either version 2 of the License, or
  11  *  (at your option) any later version.
  12  *
  13  *  This program is distributed in the hope that it will be useful,
  14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  *
  17  *  GNU General Public License for more details.
  18  *
  19  *  You should have received a copy of the GNU General Public License
  20  *  along with this program; if not, write to the Free Software
  21  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22  */
  23
  24 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  25
  26 #include "cx25821.h"
  27 #include <linux/i2c.h>
  28
  29 static unsigned int i2c_debug;
  30 module_param(i2c_debug, int, 0644);
  31 MODULE_PARM_DESC(i2c_debug, "enable debug messages [i2c]");
  32
  33 static unsigned int i2c_scan;
  34 module_param(i2c_scan, int, 0444);
  35 MODULE_PARM_DESC(i2c_scan, "scan i2c bus at insmod time");
  36
  37 #define dprintk(level, fmt, arg...)                                     \
  38 do {                                                                    \
  39         if (i2c_debug >= level)                                         \
  40                 printk(KERN_DEBUG "%s/0: " fmt, dev->name, ##arg);      \
  41 } while (0)
  42
  43 #define I2C_WAIT_DELAY 32
  44 #define I2C_WAIT_RETRY 64
  45
  46 #define I2C_EXTEND  (1 << 3)
  47 #define I2C_NOSTOP  (1 << 4)
  48
  49 static inline int i2c_slave_did_ack(struct i2c_adapter *i2c_adap)
  50 {
  51         struct cx25821_i2c *bus = i2c_adap->algo_data;
  52         struct cx25821_dev *dev = bus->dev;
  53         return cx_read(bus->reg_stat) & 0x01;
  54 }
  55
  56 static inline int i2c_is_busy(struct i2c_adapter *i2c_adap)
  57 {
  58         struct cx25821_i2c *bus = i2c_adap->algo_data;
  59         struct cx25821_dev *dev = bus->dev;
  60         return cx_read(bus->reg_stat) & 0x02 ? 1 : 0;
  61 }
  62
  63 static int i2c_wait_done(struct i2c_adapter *i2c_adap)
  64 {
  65         int count;
  66
  67         for (count = 0; count < I2C_WAIT_RETRY; count++) {
  68                 if (!i2c_is_busy(i2c_adap))
  69                         break;
  70                 udelay(I2C_WAIT_DELAY);
  71         }
  72
  73         if (I2C_WAIT_RETRY == count)
  74                 return 0;
  75
  76         return 1;
  77 }
  78
  79 static int i2c_sendbytes(struct i2c_adapter *i2c_adap,
  80                          const struct i2c_msg *msg, int joined_rlen)
  81 {
  82         struct cx25821_i2c *bus = i2c_adap->algo_data;
  83         struct cx25821_dev *dev = bus->dev;
  84         u32 wdata, addr, ctrl;
  85         int retval, cnt;
  86
  87         if (joined_rlen)
  88                 dprintk(1, "%s(msg->wlen=%d, nextmsg->rlen=%d)\n", __func__,
  89                         msg->len, joined_rlen);
  90         else
  91                 dprintk(1, "%s(msg->len=%d)\n", __func__, msg->len);
  92
  93         /* Deal with i2c probe functions with zero payload */
  94         if (msg->len == 0) {
  95                 cx_write(bus->reg_addr, msg->addr << 25);
  96                 cx_write(bus->reg_ctrl, bus->i2c_period | (1 << 2));
  97
  98                 if (!i2c_wait_done(i2c_adap))
  99                         return -EIO;
 100
 101                 if (!i2c_slave_did_ack(i2c_adap))
 102                         return -EIO;
 103
 104                 dprintk(1, "%s(): returns 0\n", __func__);
 105                 return 0;
 106         }
 107
 108         /* dev, reg + first byte */
 109         addr = (msg->addr << 25) | msg->buf[0];
 110         wdata = msg->buf[0];
 111
 112         ctrl = bus->i2c_period | (1 << 12) | (1 << 2);
 113
 114         if (msg->len > 1)
 115                 ctrl |= I2C_NOSTOP | I2C_EXTEND;
 116         else if (joined_rlen)
 117                 ctrl |= I2C_NOSTOP;
 118
 119         cx_write(bus->reg_addr, addr);
 120         cx_write(bus->reg_wdata, wdata);
 121         cx_write(bus->reg_ctrl, ctrl);
 122
 123         retval = i2c_wait_done(i2c_adap);
 124         if (retval < 0)
 125                 goto err;
 126
 127         if (retval == 0)
 128                 goto eio;
 129
 130         if (i2c_debug) {
 131                 if (!(ctrl & I2C_NOSTOP))
 132                         printk(" >\n");
 133         }
 134
 135         for (cnt = 1; cnt < msg->len; cnt++) {
 136                 /* following bytes */
 137                 wdata = msg->buf[cnt];
 138                 ctrl = bus->i2c_period | (1 << 12) | (1 << 2);
 139
 140                 if (cnt < msg->len - 1)
 141                         ctrl |= I2C_NOSTOP | I2C_EXTEND;
 142                 else if (joined_rlen)
 143                         ctrl |= I2C_NOSTOP;
 144
 145                 cx_write(bus->reg_addr, addr);
 146                 cx_write(bus->reg_wdata, wdata);
 147                 cx_write(bus->reg_ctrl, ctrl);
 148
 149                 retval = i2c_wait_done(i2c_adap);
 150                 if (retval < 0)
 151                         goto err;
 152
 153                 if (retval == 0)
 154                         goto eio;
 155
 156                 if (i2c_debug) {
 157                         dprintk(1, " %02x", msg->buf[cnt]);
 158                         if (!(ctrl & I2C_NOSTOP))
 159                                 dprintk(1, " >\n");
 160                 }
 161         }
 162
 163         return msg->len;
 164
 165 eio:
 166         retval = -EIO;
 167 err:
 168         if (i2c_debug)
 169                 pr_err(" ERR: %d\n", retval);
 170         return retval;
 171 }
 172
 173 static int i2c_readbytes(struct i2c_adapter *i2c_adap,
 174                          const struct i2c_msg *msg, int joined)
 175 {
 176         struct cx25821_i2c *bus = i2c_adap->algo_data;
 177         struct cx25821_dev *dev = bus->dev;
 178         u32 ctrl, cnt;
 179         int retval;
 180
 181         if (i2c_debug && !joined)
 182                 dprintk(1, "6-%s(msg->len=%d)\n", __func__, msg->len);
 183
 184         /* Deal with i2c probe functions with zero payload */
 185         if (msg->len == 0) {
 186                 cx_write(bus->reg_addr, msg->addr << 25);
 187                 cx_write(bus->reg_ctrl, bus->i2c_period | (1 << 2) | 1);
 188                 if (!i2c_wait_done(i2c_adap))
 189                         return -EIO;
 190                 if (!i2c_slave_did_ack(i2c_adap))
 191                         return -EIO;
 192
 193                 dprintk(1, "%s(): returns 0\n", __func__);
 194                 return 0;
 195         }
 196
 197         if (i2c_debug) {
 198                 if (joined)
 199                         dprintk(1, " R");
 200                 else
 201                         dprintk(1, " <R %02x", (msg->addr << 1) + 1);
 202         }
 203
 204         for (cnt = 0; cnt < msg->len; cnt++) {
 205
 206                 ctrl = bus->i2c_period | (1 << 12) | (1 << 2) | 1;
 207
 208                 if (cnt < msg->len - 1)
 209                         ctrl |= I2C_NOSTOP | I2C_EXTEND;
 210
 211                 cx_write(bus->reg_addr, msg->addr << 25);
 212                 cx_write(bus->reg_ctrl, ctrl);
 213
 214                 retval = i2c_wait_done(i2c_adap);
 215                 if (retval < 0)
 216                         goto err;
 217                 if (retval == 0)
 218                         goto eio;
 219                 msg->buf[cnt] = cx_read(bus->reg_rdata) & 0xff;
 220
 221                 if (i2c_debug) {
 222                         dprintk(1, " %02x", msg->buf[cnt]);
 223                         if (!(ctrl & I2C_NOSTOP))
 224                                 dprintk(1, " >\n");
 225                 }
 226         }
 227
 228         return msg->len;
 229 eio:
 230         retval = -EIO;
 231 err:
 232         if (i2c_debug)
 233                 pr_err(" ERR: %d\n", retval);
 234         return retval;
 235 }
 236
 237 static int i2c_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num)
 238 {
 239         struct cx25821_i2c *bus = i2c_adap->algo_data;
 240         struct cx25821_dev *dev = bus->dev;
 241         int i, retval = 0;
 242
 243         dprintk(1, "%s(num = %d)\n", __func__, num);
 244
 245         for (i = 0; i < num; i++) {
 246                 dprintk(1, "%s(num = %d) addr = 0x%02x  len = 0x%x\n",
 247                         __func__, num, msgs[i].addr, msgs[i].len);
 248
 249                 if (msgs[i].flags & I2C_M_RD) {
 250                         /* read */
 251                         retval = i2c_readbytes(i2c_adap, &msgs[i], 0);
 252                 } else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) &&
 253                            msgs[i].addr == msgs[i + 1].addr) {
 254                         /* write then read from same address */
 255                         retval = i2c_sendbytes(i2c_adap, &msgs[i],
 256                                         msgs[i + 1].len);
 257
 258                         if (retval < 0)
 259                                 goto err;
 260                         i++;
 261                         retval = i2c_readbytes(i2c_adap, &msgs[i], 1);
 262                 } else {
 263                         /* write */
 264                         retval = i2c_sendbytes(i2c_adap, &msgs[i], 0);
 265                 }
 266
 267                 if (retval < 0)
 268                         goto err;
 269         }
 270         return num;
 271
 272 err:
 273         return retval;
 274 }
 275
 276
 277 static u32 cx25821_functionality(struct i2c_adapter *adap)
 278 {
 279         return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C | I2C_FUNC_SMBUS_WORD_DATA |
 280                 I2C_FUNC_SMBUS_READ_WORD_DATA | I2C_FUNC_SMBUS_WRITE_WORD_DATA;
 281 }
 282
 283 static struct i2c_algorithm cx25821_i2c_algo_template = {
 284         .master_xfer = i2c_xfer,
 285         .functionality = cx25821_functionality,
 286 #ifdef NEED_ALGO_CONTROL
 287         .algo_control = dummy_algo_control,
 288 #endif
 289 };
 290
 291 static struct i2c_adapter cx25821_i2c_adap_template = {
 292         .name = "cx25821",
 293         .owner = THIS_MODULE,
 294         .algo = &cx25821_i2c_algo_template,
 295 };
 296
 297 static struct i2c_client cx25821_i2c_client_template = {
 298         .name = "cx25821 internal",
 299 };
 300
 301 /* init + register i2c adapter */
 302 int cx25821_i2c_register(struct cx25821_i2c *bus)
 303 {
 304         struct cx25821_dev *dev = bus->dev;
 305
 306         dprintk(1, "%s(bus = %d)\n", __func__, bus->nr);
 307
 308         memcpy(&bus->i2c_adap, &cx25821_i2c_adap_template,
 309                sizeof(bus->i2c_adap));
 310         memcpy(&bus->i2c_algo, &cx25821_i2c_algo_template,
 311                sizeof(bus->i2c_algo));
 312         memcpy(&bus->i2c_client, &cx25821_i2c_client_template,
 313                sizeof(bus->i2c_client));
 314
 315         bus->i2c_adap.dev.parent = &dev->pci->dev;
 316
 317         strlcpy(bus->i2c_adap.name, bus->dev->name, sizeof(bus->i2c_adap.name));
 318
 319         bus->i2c_algo.data = bus;
 320         bus->i2c_adap.algo_data = bus;
 321         i2c_set_adapdata(&bus->i2c_adap, &dev->v4l2_dev);
 322         i2c_add_adapter(&bus->i2c_adap);
 323
 324         bus->i2c_client.adapter = &bus->i2c_adap;
 325
 326         /* set up the I2c */
 327         bus->i2c_client.addr = (0x88 >> 1);
 328
 329         return bus->i2c_rc;
 330 }
 331
 332 int cx25821_i2c_unregister(struct cx25821_i2c *bus)
 333 {
 334         i2c_del_adapter(&bus->i2c_adap);
 335         return 0;
 336 }
 337
 338 void cx25821_av_clk(struct cx25821_dev *dev, int enable)
 339 {
 340         /* write 0 to bus 2 addr 0x144 via i2x_xfer() */
 341         char buffer[3];
 342         struct i2c_msg msg;
 343         dprintk(1, "%s(enabled = %d)\n", __func__, enable);
 344
 345         /* Register 0x144 */
 346         buffer[0] = 0x01;
 347         buffer[1] = 0x44;
 348         if (enable == 1)
 349                 buffer[2] = 0x05;
 350         else
 351                 buffer[2] = 0x00;
 352
 353         msg.addr = 0x44;
 354         msg.flags = I2C_M_TEN;
 355         msg.len = 3;
 356         msg.buf = buffer;
 357
 358         i2c_xfer(&dev->i2c_bus[0].i2c_adap, &msg, 1);
 359 }
 360
 361 int cx25821_i2c_read(struct cx25821_i2c *bus, u16 reg_addr, int *value)
 362 {
 363         struct i2c_client *client = &bus->i2c_client;
 364         int retval = 0;
 365         int v = 0;
 366         u8 addr[2] = { 0, 0 };
 367         u8 buf[4] = { 0, 0, 0, 0 };
 368
 369         struct i2c_msg msgs[2] = {
 370                 {
 371                         .addr = client->addr,
 372                         .flags = 0,
 373                         .len = 2,
 374                         .buf = addr,
 375                 }, {
 376                         .addr = client->addr,
 377                         .flags = I2C_M_RD,
 378                         .len = 4,
 379                         .buf = buf,
 380                 }
 381         };
 382
 383         addr[0] = (reg_addr >> 8);
 384         addr[1] = (reg_addr & 0xff);
 385         msgs[0].addr = 0x44;
 386         msgs[1].addr = 0x44;
 387
 388         retval = i2c_xfer(client->adapter, msgs, 2);
 389
 390         v = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0];
 391         *value = v;
 392
 393         return v;
 394 }
 395
 396 int cx25821_i2c_write(struct cx25821_i2c *bus, u16 reg_addr, int value)
 397 {
 398         struct i2c_client *client = &bus->i2c_client;
 399         int retval = 0;
 400         u8 buf[6] = { 0, 0, 0, 0, 0, 0 };
 401
 402         struct i2c_msg msgs[1] = {
 403                 {
 404                         .addr = client->addr,
 405                         .flags = 0,
 406                         .len = 6,
 407                         .buf = buf,
 408                 }
 409         };
 410
 411         buf[0] = reg_addr >> 8;
 412         buf[1] = reg_addr & 0xff;
 413         buf[5] = (value >> 24) & 0xff;
 414         buf[4] = (value >> 16) & 0xff;
 415         buf[3] = (value >> 8) & 0xff;
 416         buf[2] = value & 0xff;
 417         client->flags = 0;
 418         msgs[0].addr = 0x44;
 419
 420         retval = i2c_xfer(client->adapter, msgs, 1);
 421
 422         return retval;
 423 }