release/src-rt-6.x.4708/linux/linux-2.6.36/drivers/media/video/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 <linux/module.h>
  23 #include <linux/moduleparam.h>
  24 #include <linux/init.h>
  25 #include <linux/delay.h>
  26 #include <linux/io.h>
  27
  28 #include "au0828.h"
  29
  30 #include <media/v4l2-common.h>
  31
  32 static int i2c_scan;
  33 module_param(i2c_scan, int, 0444);
  34 MODULE_PARM_DESC(i2c_scan, "scan i2c bus at insmod time");
  35
  36 #define I2C_WAIT_DELAY 512
  37 #define I2C_WAIT_RETRY 64
  38
  39 static inline int i2c_slave_did_write_ack(struct i2c_adapter *i2c_adap)
  40 {
  41         struct au0828_dev *dev = i2c_adap->algo_data;
  42         return au0828_read(dev, AU0828_I2C_STATUS_201) &
  43                 AU0828_I2C_STATUS_NO_WRITE_ACK ? 0 : 1;
  44 }
  45
  46 static inline int i2c_slave_did_read_ack(struct i2c_adapter *i2c_adap)
  47 {
  48         struct au0828_dev *dev = i2c_adap->algo_data;
  49         return au0828_read(dev, AU0828_I2C_STATUS_201) &
  50                 AU0828_I2C_STATUS_NO_READ_ACK ? 0 : 1;
  51 }
  52
  53 static int i2c_wait_read_ack(struct i2c_adapter *i2c_adap)
  54 {
  55         int count;
  56
  57         for (count = 0; count < I2C_WAIT_RETRY; count++) {
  58                 if (!i2c_slave_did_read_ack(i2c_adap))
  59                         break;
  60                 udelay(I2C_WAIT_DELAY);
  61         }
  62
  63         if (I2C_WAIT_RETRY == count)
  64                 return 0;
  65
  66         return 1;
  67 }
  68
  69 static inline int i2c_is_read_busy(struct i2c_adapter *i2c_adap)
  70 {
  71         struct au0828_dev *dev = i2c_adap->algo_data;
  72         return au0828_read(dev, AU0828_I2C_STATUS_201) &
  73                 AU0828_I2C_STATUS_READ_DONE ? 0 : 1;
  74 }
  75
  76 static int i2c_wait_read_done(struct i2c_adapter *i2c_adap)
  77 {
  78         int count;
  79
  80         for (count = 0; count < I2C_WAIT_RETRY; count++) {
  81                 if (!i2c_is_read_busy(i2c_adap))
  82                         break;
  83                 udelay(I2C_WAIT_DELAY);
  84         }
  85
  86         if (I2C_WAIT_RETRY == count)
  87                 return 0;
  88
  89         return 1;
  90 }
  91
  92 static inline int i2c_is_write_done(struct i2c_adapter *i2c_adap)
  93 {
  94         struct au0828_dev *dev = i2c_adap->algo_data;
  95         return au0828_read(dev, AU0828_I2C_STATUS_201) &
  96                 AU0828_I2C_STATUS_WRITE_DONE ? 1 : 0;
  97 }
  98
  99 static int i2c_wait_write_done(struct i2c_adapter *i2c_adap)
 100 {
 101         int count;
 102
 103         for (count = 0; count < I2C_WAIT_RETRY; count++) {
 104                 if (i2c_is_write_done(i2c_adap))
 105                         break;
 106                 udelay(I2C_WAIT_DELAY);
 107         }
 108
 109         if (I2C_WAIT_RETRY == count)
 110                 return 0;
 111
 112         return 1;
 113 }
 114
 115 static inline int i2c_is_busy(struct i2c_adapter *i2c_adap)
 116 {
 117         struct au0828_dev *dev = i2c_adap->algo_data;
 118         return au0828_read(dev, AU0828_I2C_STATUS_201) &
 119                 AU0828_I2C_STATUS_BUSY ? 1 : 0;
 120 }
 121
 122 static int i2c_wait_done(struct i2c_adapter *i2c_adap)
 123 {
 124         int count;
 125
 126         for (count = 0; count < I2C_WAIT_RETRY; count++) {
 127                 if (!i2c_is_busy(i2c_adap))
 128                         break;
 129                 udelay(I2C_WAIT_DELAY);
 130         }
 131
 132         if (I2C_WAIT_RETRY == count)
 133                 return 0;
 134
 135         return 1;
 136 }
 137
 138 static int i2c_sendbytes(struct i2c_adapter *i2c_adap,
 139         const struct i2c_msg *msg, int joined_rlen)
 140 {
 141         int i, strobe = 0;
 142         struct au0828_dev *dev = i2c_adap->algo_data;
 143
 144         dprintk(4, "%s()\n", __func__);
 145
 146         au0828_write(dev, AU0828_I2C_MULTIBYTE_MODE_2FF, 0x01);
 147
 148         /* Set the I2C clock */
 149         au0828_write(dev, AU0828_I2C_CLK_DIVIDER_202,
 150                      dev->board.i2c_clk_divider);
 151
 152         /* Hardware needs 8 bit addresses */
 153         au0828_write(dev, AU0828_I2C_DEST_ADDR_203, msg->addr << 1);
 154
 155         dprintk(4, "SEND: %02x\n", msg->addr);
 156
 157         /* Deal with i2c_scan */
 158         if (msg->len == 0) {
 159                 /* The analog tuner detection code makes use of the SMBUS_QUICK
 160                    message (which involves a zero length i2c write).  To avoid
 161                    checking the status register when we didn't strobe out any
 162                    actual bytes to the bus, just do a read check.  This is
 163                    consistent with how I saw i2c device checking done in the
 164                    USB trace of the Windows driver */
 165                 au0828_write(dev, AU0828_I2C_TRIGGER_200,
 166                              AU0828_I2C_TRIGGER_READ);
 167
 168                 if (!i2c_wait_done(i2c_adap))
 169                         return -EIO;
 170
 171                 if (i2c_wait_read_ack(i2c_adap))
 172                         return -EIO;
 173
 174                 return 0;
 175         }
 176
 177         for (i = 0; i < msg->len;) {
 178
 179                 dprintk(4, " %02x\n", msg->buf[i]);
 180
 181                 au0828_write(dev, AU0828_I2C_WRITE_FIFO_205, msg->buf[i]);
 182
 183                 strobe++;
 184                 i++;
 185
 186                 if ((strobe >= 4) || (i >= msg->len)) {
 187
 188                         /* Strobe the byte into the bus */
 189                         if (i < msg->len)
 190                                 au0828_write(dev, AU0828_I2C_TRIGGER_200,
 191                                              AU0828_I2C_TRIGGER_WRITE |
 192                                              AU0828_I2C_TRIGGER_HOLD);
 193                         else
 194                                 au0828_write(dev, AU0828_I2C_TRIGGER_200,
 195                                              AU0828_I2C_TRIGGER_WRITE);
 196
 197                         /* Reset strobe trigger */
 198                         strobe = 0;
 199
 200                         if (!i2c_wait_write_done(i2c_adap))
 201                                 return -EIO;
 202
 203                 }
 204
 205         }
 206         if (!i2c_wait_done(i2c_adap))
 207                 return -EIO;
 208
 209         dprintk(4, "\n");
 210
 211         return msg->len;
 212 }
 213
 214 static int i2c_readbytes(struct i2c_adapter *i2c_adap,
 215         const struct i2c_msg *msg, int joined)
 216 {
 217         struct au0828_dev *dev = i2c_adap->algo_data;
 218         int i;
 219
 220         dprintk(4, "%s()\n", __func__);
 221
 222         au0828_write(dev, AU0828_I2C_MULTIBYTE_MODE_2FF, 0x01);
 223
 224         /* Set the I2C clock */
 225         au0828_write(dev, AU0828_I2C_CLK_DIVIDER_202,
 226                      dev->board.i2c_clk_divider);
 227
 228         /* Hardware needs 8 bit addresses */
 229         au0828_write(dev, AU0828_I2C_DEST_ADDR_203, msg->addr << 1);
 230
 231         dprintk(4, " RECV:\n");
 232
 233         /* Deal with i2c_scan */
 234         if (msg->len == 0) {
 235                 au0828_write(dev, AU0828_I2C_TRIGGER_200,
 236                              AU0828_I2C_TRIGGER_READ);
 237
 238                 if (i2c_wait_read_ack(i2c_adap))
 239                         return -EIO;
 240                 return 0;
 241         }
 242
 243         for (i = 0; i < msg->len;) {
 244
 245                 i++;
 246
 247                 if (i < msg->len)
 248                         au0828_write(dev, AU0828_I2C_TRIGGER_200,
 249                                      AU0828_I2C_TRIGGER_READ |
 250                                      AU0828_I2C_TRIGGER_HOLD);
 251                 else
 252                         au0828_write(dev, AU0828_I2C_TRIGGER_200,
 253                                      AU0828_I2C_TRIGGER_READ);
 254
 255                 if (!i2c_wait_read_done(i2c_adap))
 256                         return -EIO;
 257
 258                 msg->buf[i-1] = au0828_read(dev, AU0828_I2C_READ_FIFO_209) &
 259                         0xff;
 260
 261                 dprintk(4, " %02x\n", msg->buf[i-1]);
 262         }
 263         if (!i2c_wait_done(i2c_adap))
 264                 return -EIO;
 265
 266         dprintk(4, "\n");
 267
 268         return msg->len;
 269 }
 270
 271 static int i2c_xfer(struct i2c_adapter *i2c_adap,
 272                     struct i2c_msg *msgs, int num)
 273 {
 274         int i, retval = 0;
 275
 276         dprintk(4, "%s(num = %d)\n", __func__, num);
 277
 278         for (i = 0; i < num; i++) {
 279                 dprintk(4, "%s(num = %d) addr = 0x%02x  len = 0x%x\n",
 280                         __func__, num, msgs[i].addr, msgs[i].len);
 281                 if (msgs[i].flags & I2C_M_RD) {
 282                         /* read */
 283                         retval = i2c_readbytes(i2c_adap, &msgs[i], 0);
 284                 } else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) &&
 285                            msgs[i].addr == msgs[i + 1].addr) {
 286                         /* write then read from same address */
 287                         retval = i2c_sendbytes(i2c_adap, &msgs[i],
 288                                                msgs[i + 1].len);
 289                         if (retval < 0)
 290                                 goto err;
 291                         i++;
 292                         retval = i2c_readbytes(i2c_adap, &msgs[i], 1);
 293                 } else {
 294                         /* write */
 295                         retval = i2c_sendbytes(i2c_adap, &msgs[i], 0);
 296                 }
 297                 if (retval < 0)
 298                         goto err;
 299         }
 300         return num;
 301
 302 err:
 303         return retval;
 304 }
 305
 306 static u32 au0828_functionality(struct i2c_adapter *adap)
 307 {
 308         return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C;
 309 }
 310
 311 static struct i2c_algorithm au0828_i2c_algo_template = {
 312         .master_xfer    = i2c_xfer,
 313         .functionality  = au0828_functionality,
 314 };
 315
 316 /* ----------------------------------------------------------------------- */
 317
 318 static struct i2c_adapter au0828_i2c_adap_template = {
 319         .name              = DRIVER_NAME,
 320         .owner             = THIS_MODULE,
 321         .algo              = &au0828_i2c_algo_template,
 322 };
 323
 324 static struct i2c_client au0828_i2c_client_template = {
 325         .name   = "au0828 internal",
 326 };
 327
 328 static char *i2c_devs[128] = {
 329         [0x8e >> 1] = "au8522",
 330         [0xa0 >> 1] = "eeprom",
 331         [0xc2 >> 1] = "tuner/xc5000",
 332 };
 333
 334 static void do_i2c_scan(char *name, struct i2c_client *c)
 335 {
 336         unsigned char buf;
 337         int i, rc;
 338
 339         for (i = 0; i < 128; i++) {
 340                 c->addr = i;
 341                 rc = i2c_master_recv(c, &buf, 0);
 342                 if (rc < 0)
 343                         continue;
 344                 printk(KERN_INFO "%s: i2c scan: found device @ 0x%x  [%s]\n",
 345                        name, i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
 346         }
 347 }
 348
 349 /* init + register i2c algo-bit adapter */
 350 int au0828_i2c_register(struct au0828_dev *dev)
 351 {
 352         dprintk(1, "%s()\n", __func__);
 353
 354         memcpy(&dev->i2c_adap, &au0828_i2c_adap_template,
 355                sizeof(dev->i2c_adap));
 356         memcpy(&dev->i2c_algo, &au0828_i2c_algo_template,
 357                sizeof(dev->i2c_algo));
 358         memcpy(&dev->i2c_client, &au0828_i2c_client_template,
 359                sizeof(dev->i2c_client));
 360
 361         dev->i2c_adap.dev.parent = &dev->usbdev->dev;
 362
 363         strlcpy(dev->i2c_adap.name, DRIVER_NAME,
 364                 sizeof(dev->i2c_adap.name));
 365
 366         dev->i2c_adap.algo = &dev->i2c_algo;
 367         dev->i2c_adap.algo_data = dev;
 368         i2c_set_adapdata(&dev->i2c_adap, &dev->v4l2_dev);
 369         i2c_add_adapter(&dev->i2c_adap);
 370
 371         dev->i2c_client.adapter = &dev->i2c_adap;
 372
 373         if (0 == dev->i2c_rc) {
 374                 printk(KERN_INFO "%s: i2c bus registered\n", DRIVER_NAME);
 375                 if (i2c_scan)
 376                         do_i2c_scan(DRIVER_NAME, &dev->i2c_client);
 377         } else
 378                 printk(KERN_INFO "%s: i2c bus register FAILED\n", DRIVER_NAME);
 379
 380         return dev->i2c_rc;
 381 }
 382
 383 int au0828_i2c_unregister(struct au0828_dev *dev)
 384 {
 385         i2c_del_adapter(&dev->i2c_adap);
 386         return 0;
 387 }