drivers/media/usb/au0828/au0828-i2c.c

   1 /*
   2  *  Driver for the Auvitek AU0828 USB bridge
   3  *
   4  *  Copyright (c) 2008 Steven Toth <stoth@linuxtv.org>
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation; either version 2 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *
  15  *  GNU General Public License for more details.
  16  *
  17  *  You should have received a copy of the GNU General Public License
  18  *  along with this program; if not, write to the Free Software
  19  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20  */
  21
  22 #include "au0828.h"
  23
  24 #include <linux/module.h>
  25 #include <linux/moduleparam.h>
  26 #include <linux/init.h>
  27 #include <linux/delay.h>
  28 #include <linux/io.h>
  29
  30 #include "media/tuner.h"
  31 #include <media/v4l2-common.h>
  32
  33 static 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 I2C_WAIT_DELAY 25
  38 #define I2C_WAIT_RETRY 1000
  39
  40 static inline int i2c_slave_did_write_ack(struct i2c_adapter *i2c_adap)
  41 {
  42         struct au0828_dev *dev = i2c_adap->algo_data;
  43         return au0828_read(dev, AU0828_I2C_STATUS_201) &
  44                 AU0828_I2C_STATUS_NO_WRITE_ACK ? 0 : 1;
  45 }
  46
  47 static inline int i2c_slave_did_read_ack(struct i2c_adapter *i2c_adap)
  48 {
  49         struct au0828_dev *dev = i2c_adap->algo_data;
  50         return au0828_read(dev, AU0828_I2C_STATUS_201) &
  51                 AU0828_I2C_STATUS_NO_READ_ACK ? 0 : 1;
  52 }
  53
  54 static int i2c_wait_read_ack(struct i2c_adapter *i2c_adap)
  55 {
  56         int count;
  57
  58         for (count = 0; count < I2C_WAIT_RETRY; count++) {
  59                 if (!i2c_slave_did_read_ack(i2c_adap))
  60                         break;
  61                 udelay(I2C_WAIT_DELAY);
  62         }
  63
  64         if (I2C_WAIT_RETRY == count)
  65                 return 0;
  66
  67         return 1;
  68 }
  69
  70 static inline int i2c_is_read_busy(struct i2c_adapter *i2c_adap)
  71 {
  72         struct au0828_dev *dev = i2c_adap->algo_data;
  73         return au0828_read(dev, AU0828_I2C_STATUS_201) &
  74                 AU0828_I2C_STATUS_READ_DONE ? 0 : 1;
  75 }
  76
  77 static int i2c_wait_read_done(struct i2c_adapter *i2c_adap)
  78 {
  79         int count;
  80
  81         for (count = 0; count < I2C_WAIT_RETRY; count++) {
  82                 if (!i2c_is_read_busy(i2c_adap))
  83                         break;
  84                 udelay(I2C_WAIT_DELAY);
  85         }
  86
  87         if (I2C_WAIT_RETRY == count)
  88                 return 0;
  89
  90         return 1;
  91 }
  92
  93 static inline int i2c_is_write_done(struct i2c_adapter *i2c_adap)
  94 {
  95         struct au0828_dev *dev = i2c_adap->algo_data;
  96         return au0828_read(dev, AU0828_I2C_STATUS_201) &
  97                 AU0828_I2C_STATUS_WRITE_DONE ? 1 : 0;
  98 }
  99
 100 static int i2c_wait_write_done(struct i2c_adapter *i2c_adap)
 101 {
 102         int count;
 103
 104         for (count = 0; count < I2C_WAIT_RETRY; count++) {
 105                 if (i2c_is_write_done(i2c_adap))
 106                         break;
 107                 udelay(I2C_WAIT_DELAY);
 108         }
 109
 110         if (I2C_WAIT_RETRY == count)
 111                 return 0;
 112
 113         return 1;
 114 }
 115
 116 static inline int i2c_is_busy(struct i2c_adapter *i2c_adap)
 117 {
 118         struct au0828_dev *dev = i2c_adap->algo_data;
 119         return au0828_read(dev, AU0828_I2C_STATUS_201) &
 120                 AU0828_I2C_STATUS_BUSY ? 1 : 0;
 121 }
 122
 123 static int i2c_wait_done(struct i2c_adapter *i2c_adap)
 124 {
 125         int count;
 126
 127         for (count = 0; count < I2C_WAIT_RETRY; count++) {
 128                 if (!i2c_is_busy(i2c_adap))
 129                         break;
 130                 udelay(I2C_WAIT_DELAY);
 131         }
 132
 133         if (I2C_WAIT_RETRY == count)
 134                 return 0;
 135
 136         return 1;
 137 }
 138
 139 /* FIXME: Implement join handling correctly */
 140 static int i2c_sendbytes(struct i2c_adapter *i2c_adap,
 141         const struct i2c_msg *msg, int joined_rlen)
 142 {
 143         int i, strobe = 0;
 144         struct au0828_dev *dev = i2c_adap->algo_data;
 145         u8 i2c_speed = dev->board.i2c_clk_divider;
 146
 147         dprintk(4, "%s()\n", __func__);
 148
 149         au0828_write(dev, AU0828_I2C_MULTIBYTE_MODE_2FF, 0x01);
 150
 151         if (((dev->board.tuner_type == TUNER_XC5000) ||
 152              (dev->board.tuner_type == TUNER_XC5000C)) &&
 153             (dev->board.tuner_addr == msg->addr)) {
 154                 /*
 155                  * Due to I2C clock stretch, we need to use a lower speed
 156                  * on xc5000 for commands. However, firmware transfer can
 157                  * speed up to 400 KHz.
 158                  */
 159                 if (msg->len == 64)
 160                         i2c_speed = AU0828_I2C_CLK_250KHZ;
 161                 else
 162                         i2c_speed = AU0828_I2C_CLK_20KHZ;
 163         }
 164         /* Set the I2C clock */
 165         au0828_write(dev, AU0828_I2C_CLK_DIVIDER_202, i2c_speed);
 166
 167         /* Hardware needs 8 bit addresses */
 168         au0828_write(dev, AU0828_I2C_DEST_ADDR_203, msg->addr << 1);
 169
 170         dprintk(4, "SEND: %02x\n", msg->addr);
 171
 172         /* Deal with i2c_scan */
 173         if (msg->len == 0) {
 174                 /* The analog tuner detection code makes use of the SMBUS_QUICK
 175                    message (which involves a zero length i2c write).  To avoid
 176                    checking the status register when we didn't strobe out any
 177                    actual bytes to the bus, just do a read check.  This is
 178                    consistent with how I saw i2c device checking done in the
 179                    USB trace of the Windows driver */
 180                 au0828_write(dev, AU0828_I2C_TRIGGER_200,
 181                              AU0828_I2C_TRIGGER_READ);
 182
 183                 if (!i2c_wait_done(i2c_adap))
 184                         return -EIO;
 185
 186                 if (i2c_wait_read_ack(i2c_adap))
 187                         return -EIO;
 188
 189                 return 0;
 190         }
 191
 192         for (i = 0; i < msg->len;) {
 193
 194                 dprintk(4, " %02x\n", msg->buf[i]);
 195
 196                 au0828_write(dev, AU0828_I2C_WRITE_FIFO_205, msg->buf[i]);
 197
 198                 strobe++;
 199                 i++;
 200
 201                 if ((strobe >= 4) || (i >= msg->len)) {
 202
 203                         /* Strobe the byte into the bus */
 204                         if (i < msg->len)
 205                                 au0828_write(dev, AU0828_I2C_TRIGGER_200,
 206                                              AU0828_I2C_TRIGGER_WRITE |
 207                                              AU0828_I2C_TRIGGER_HOLD);
 208                         else
 209                                 au0828_write(dev, AU0828_I2C_TRIGGER_200,
 210                                              AU0828_I2C_TRIGGER_WRITE);
 211
 212                         /* Reset strobe trigger */
 213                         strobe = 0;
 214
 215                         if (!i2c_wait_write_done(i2c_adap))
 216                                 return -EIO;
 217
 218                 }
 219
 220         }
 221         if (!i2c_wait_done(i2c_adap))
 222                 return -EIO;
 223
 224         dprintk(4, "\n");
 225
 226         return msg->len;
 227 }
 228
 229 /* FIXME: Implement join handling correctly */
 230 static int i2c_readbytes(struct i2c_adapter *i2c_adap,
 231         const struct i2c_msg *msg, int joined)
 232 {
 233         struct au0828_dev *dev = i2c_adap->algo_data;
 234         u8 i2c_speed = dev->board.i2c_clk_divider;
 235         int i;
 236
 237         dprintk(4, "%s()\n", __func__);
 238
 239         au0828_write(dev, AU0828_I2C_MULTIBYTE_MODE_2FF, 0x01);
 240
 241         /*
 242          * Due to xc5000c clock stretch, we cannot use full speed at
 243          * readings from xc5000, as otherwise they'll fail.
 244          */
 245         if (((dev->board.tuner_type == TUNER_XC5000) ||
 246              (dev->board.tuner_type == TUNER_XC5000C)) &&
 247             (dev->board.tuner_addr == msg->addr))
 248                 i2c_speed = AU0828_I2C_CLK_20KHZ;
 249
 250         /* Set the I2C clock */
 251         au0828_write(dev, AU0828_I2C_CLK_DIVIDER_202, i2c_speed);
 252
 253         /* Hardware needs 8 bit addresses */
 254         au0828_write(dev, AU0828_I2C_DEST_ADDR_203, msg->addr << 1);
 255
 256         dprintk(4, " RECV:\n");
 257
 258         /* Deal with i2c_scan */
 259         if (msg->len == 0) {
 260                 au0828_write(dev, AU0828_I2C_TRIGGER_200,
 261                              AU0828_I2C_TRIGGER_READ);
 262
 263                 if (i2c_wait_read_ack(i2c_adap))
 264                         return -EIO;
 265                 return 0;
 266         }
 267
 268         for (i = 0; i < msg->len;) {
 269
 270                 i++;
 271
 272                 if (i < msg->len)
 273                         au0828_write(dev, AU0828_I2C_TRIGGER_200,
 274                                      AU0828_I2C_TRIGGER_READ |
 275                                      AU0828_I2C_TRIGGER_HOLD);
 276                 else
 277                         au0828_write(dev, AU0828_I2C_TRIGGER_200,
 278                                      AU0828_I2C_TRIGGER_READ);
 279
 280                 if (!i2c_wait_read_done(i2c_adap))
 281                         return -EIO;
 282
 283                 msg->buf[i-1] = au0828_read(dev, AU0828_I2C_READ_FIFO_209) &
 284                         0xff;
 285
 286                 dprintk(4, " %02x\n", msg->buf[i-1]);
 287         }
 288         if (!i2c_wait_done(i2c_adap))
 289                 return -EIO;
 290
 291         dprintk(4, "\n");
 292
 293         return msg->len;
 294 }
 295
 296 static int i2c_xfer(struct i2c_adapter *i2c_adap,
 297                     struct i2c_msg *msgs, int num)
 298 {
 299         int i, retval = 0;
 300
 301         dprintk(4, "%s(num = %d)\n", __func__, num);
 302
 303         for (i = 0; i < num; i++) {
 304                 dprintk(4, "%s(num = %d) addr = 0x%02x  len = 0x%x\n",
 305                         __func__, num, msgs[i].addr, msgs[i].len);
 306                 if (msgs[i].flags & I2C_M_RD) {
 307                         /* read */
 308                         retval = i2c_readbytes(i2c_adap, &msgs[i], 0);
 309                 } else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) &&
 310                            msgs[i].addr == msgs[i + 1].addr) {
 311                         /* write then read from same address */
 312                         retval = i2c_sendbytes(i2c_adap, &msgs[i],
 313                                                msgs[i + 1].len);
 314                         if (retval < 0)
 315                                 goto err;
 316                         i++;
 317                         retval = i2c_readbytes(i2c_adap, &msgs[i], 1);
 318                 } else {
 319                         /* write */
 320                         retval = i2c_sendbytes(i2c_adap, &msgs[i], 0);
 321                 }
 322                 if (retval < 0)
 323                         goto err;
 324         }
 325         return num;
 326
 327 err:
 328         return retval;
 329 }
 330
 331 static u32 au0828_functionality(struct i2c_adapter *adap)
 332 {
 333         return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C;
 334 }
 335
 336 static struct i2c_algorithm au0828_i2c_algo_template = {
 337         .master_xfer    = i2c_xfer,
 338         .functionality  = au0828_functionality,
 339 };
 340
 341 /* ----------------------------------------------------------------------- */
 342
 343 static struct i2c_adapter au0828_i2c_adap_template = {
 344         .name              = KBUILD_MODNAME,
 345         .owner             = THIS_MODULE,
 346         .algo              = &au0828_i2c_algo_template,
 347 };
 348
 349 static struct i2c_client au0828_i2c_client_template = {
 350         .name   = "au0828 internal",
 351 };
 352
 353 static char *i2c_devs[128] = {
 354         [0x8e >> 1] = "au8522",
 355         [0xa0 >> 1] = "eeprom",
 356         [0xc2 >> 1] = "tuner/xc5000",
 357 };
 358
 359 static void do_i2c_scan(char *name, struct i2c_client *c)
 360 {
 361         unsigned char buf;
 362         int i, rc;
 363
 364         for (i = 0; i < 128; i++) {
 365                 c->addr = i;
 366                 rc = i2c_master_recv(c, &buf, 0);
 367                 if (rc < 0)
 368                         continue;
 369                 pr_info("%s: i2c scan: found device @ 0x%x  [%s]\n",
 370                        name, i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
 371         }
 372 }
 373
 374 /* init + register i2c adapter */
 375 int au0828_i2c_register(struct au0828_dev *dev)
 376 {
 377         dprintk(1, "%s()\n", __func__);
 378
 379         dev->i2c_adap = au0828_i2c_adap_template;
 380         dev->i2c_algo = au0828_i2c_algo_template;
 381         dev->i2c_client = au0828_i2c_client_template;
 382
 383         dev->i2c_adap.dev.parent = &dev->usbdev->dev;
 384
 385         strlcpy(dev->i2c_adap.name, KBUILD_MODNAME,
 386                 sizeof(dev->i2c_adap.name));
 387
 388         dev->i2c_adap.algo = &dev->i2c_algo;
 389         dev->i2c_adap.algo_data = dev;
 390 #ifdef CONFIG_VIDEO_AU0828_V4L2
 391         i2c_set_adapdata(&dev->i2c_adap, &dev->v4l2_dev);
 392 #else
 393         i2c_set_adapdata(&dev->i2c_adap, dev);
 394 #endif
 395         i2c_add_adapter(&dev->i2c_adap);
 396
 397         dev->i2c_client.adapter = &dev->i2c_adap;
 398
 399         if (0 == dev->i2c_rc) {
 400                 pr_info("i2c bus registered\n");
 401                 if (i2c_scan)
 402                         do_i2c_scan(KBUILD_MODNAME, &dev->i2c_client);
 403         } else
 404                 pr_info("i2c bus register FAILED\n");
 405
 406         return dev->i2c_rc;
 407 }
 408
 409 int au0828_i2c_unregister(struct au0828_dev *dev)
 410 {
 411         i2c_del_adapter(&dev->i2c_adap);
 412         return 0;
 413 }
 414