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