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

   1 /*
   2  *  Driver for the Auvitek AU0828 USB bridge
   3  *
   4  *  Copyright (c) 2008 Steven Toth <stoth@hauppauge.com>
   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 <asm/io.h>
  27
  28 #include "au0828.h"
  29
  30 #include <media/v4l2-common.h>
  31
  32 unsigned int i2c_debug = 0;
  33 module_param(i2c_debug, int, 0444);
  34 MODULE_PARM_DESC(i2c_debug, "enable debug messages [i2c]");
  35
  36 unsigned int i2c_scan = 0;
  37 module_param(i2c_scan, int, 0444);
  38 MODULE_PARM_DESC(i2c_scan, "scan i2c bus at insmod time");
  39
  40 #define I2C_WAIT_DELAY 512
  41 #define I2C_WAIT_RETRY 64
  42
  43 static inline int i2c_slave_did_write_ack(struct i2c_adapter *i2c_adap)
  44 {
  45         struct au0828_dev *dev = i2c_adap->algo_data;
  46         return au0828_read(dev, REG_201) & 0x08 ? 0 : 1;
  47 }
  48
  49 static inline int i2c_slave_did_read_ack(struct i2c_adapter *i2c_adap)
  50 {
  51         struct au0828_dev *dev = i2c_adap->algo_data;
  52         return au0828_read(dev, REG_201) & 0x02 ? 0 : 1;
  53 }
  54
  55 static int i2c_wait_read_ack(struct i2c_adapter *i2c_adap)
  56 {
  57         int count;
  58
  59         for (count = 0; count < I2C_WAIT_RETRY; count++) {
  60                 if (!i2c_slave_did_read_ack(i2c_adap))
  61                         break;
  62                 udelay(I2C_WAIT_DELAY);
  63         }
  64
  65         if (I2C_WAIT_RETRY == count)
  66                 return 0;
  67
  68         return 1;
  69 }
  70
  71 static inline int i2c_is_read_busy(struct i2c_adapter *i2c_adap)
  72 {
  73         struct au0828_dev *dev = i2c_adap->algo_data;
  74         return au0828_read(dev, REG_201) & 0x01 ? 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, REG_201) & 0x04 ? 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, REG_201) & 0x10 ? 1 : 0;
 119 }
 120
 121 static int i2c_wait_done(struct i2c_adapter *i2c_adap)
 122 {
 123         int count;
 124
 125         for (count = 0; count < I2C_WAIT_RETRY; count++) {
 126                 if (!i2c_is_busy(i2c_adap))
 127                         break;
 128                 udelay(I2C_WAIT_DELAY);
 129         }
 130
 131         if (I2C_WAIT_RETRY == count)
 132                 return 0;
 133
 134         return 1;
 135 }
 136
 137 /* FIXME: Implement join handling correctly */
 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", __FUNCTION__);
 145
 146         au0828_write(dev, REG_2FF, 0x01);
 147         au0828_write(dev, REG_202, 0x07);
 148
 149         /* Hardware needs 8 bit addresses */
 150         au0828_write(dev, REG_203, msg->addr << 1);
 151
 152         dprintk(4, "SEND: %02x\n", msg->addr);
 153
 154         for (i=0; i < msg->len;) {
 155
 156                 dprintk(4, " %02x\n", msg->buf[i]);
 157
 158                 au0828_write(dev, REG_205, msg->buf[i]);
 159
 160                 strobe++;
 161                 i++;
 162
 163                 if ((strobe >= 4) || (i >= msg->len)) {
 164
 165                         /* Strobe the byte into the bus */
 166                         if (i < msg->len)
 167                                 au0828_write(dev, REG_200, 0x41);
 168                         else
 169                                 au0828_write(dev, REG_200, 0x01);
 170
 171                         /* Reset strobe trigger */
 172                         strobe = 0;
 173
 174                         if (!i2c_wait_write_done(i2c_adap))
 175                                 return -EIO;
 176
 177                 }
 178
 179         }
 180         if (!i2c_wait_done(i2c_adap))
 181                 return -EIO;
 182
 183         dprintk(4, "\n");
 184
 185         return msg->len;
 186 }
 187
 188 /* FIXME: Implement join handling correctly */
 189 static int i2c_readbytes(struct i2c_adapter *i2c_adap,
 190         const struct i2c_msg *msg, int joined)
 191 {
 192         struct au0828_dev *dev = i2c_adap->algo_data;
 193         int i;
 194
 195         dprintk(4, "%s()\n", __FUNCTION__);
 196
 197         au0828_write(dev, REG_2FF, 0x01);
 198         au0828_write(dev, REG_202, 0x07);
 199
 200         /* Hardware needs 8 bit addresses */
 201         au0828_write(dev, REG_203, msg->addr << 1);
 202
 203         dprintk(4, " RECV:\n");
 204
 205         /* Deal with i2c_scan */
 206         if (msg->len == 0) {
 207                 au0828_write(dev, REG_200, 0x20);
 208                 if (i2c_wait_read_ack(i2c_adap))
 209                         return -EIO;
 210                 return 0;
 211         }
 212
 213         for (i=0; i < msg->len;) {
 214
 215                 i++;
 216
 217                 if (i < msg->len)
 218                         au0828_write(dev, REG_200, 0x60);
 219                 else
 220                         au0828_write(dev, REG_200, 0x20);
 221
 222                 if (!i2c_wait_read_done(i2c_adap))
 223                         return -EIO;
 224
 225                 msg->buf[i-1] = au0828_read(dev, REG_209) & 0xff;
 226
 227                 dprintk(4, " %02x\n", msg->buf[i-1]);
 228         }
 229         if (!i2c_wait_done(i2c_adap))
 230                 return -EIO;
 231
 232         dprintk(4, "\n");
 233
 234         return msg->len;
 235 }
 236
 237 static int i2c_xfer(struct i2c_adapter *i2c_adap,
 238                     struct i2c_msg *msgs, int num)
 239 {
 240         int i, retval = 0;
 241
 242         dprintk(4, "%s(num = %d)\n", __FUNCTION__, num);
 243
 244         for (i = 0 ; i < num; i++) {
 245                 dprintk(4, "%s(num = %d) addr = 0x%02x  len = 0x%x\n",
 246                         __FUNCTION__, num, msgs[i].addr, msgs[i].len);
 247                 if (msgs[i].flags & I2C_M_RD) {
 248                         /* read */
 249                         retval = i2c_readbytes(i2c_adap, &msgs[i], 0);
 250                 } else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) &&
 251                            msgs[i].addr == msgs[i + 1].addr) {
 252                         /* write then read from same address */
 253                         retval = i2c_sendbytes(i2c_adap, &msgs[i],
 254                                                msgs[i + 1].len);
 255                         if (retval < 0)
 256                                 goto err;
 257                         i++;
 258                         retval = i2c_readbytes(i2c_adap, &msgs[i], 1);
 259                 } else {
 260                         /* write */
 261                         retval = i2c_sendbytes(i2c_adap, &msgs[i], 0);
 262                 }
 263                 if (retval < 0)
 264                         goto err;
 265         }
 266         return num;
 267
 268 err:
 269         return retval;
 270 }
 271
 272 static int attach_inform(struct i2c_client *client)
 273 {
 274         dprintk(1, "%s i2c attach [addr=0x%x,client=%s]\n",
 275                 client->driver->driver.name, client->addr, client->name);
 276
 277         if (!client->driver->command)
 278                 return 0;
 279
 280         return 0;
 281 }
 282
 283 static int detach_inform(struct i2c_client *client)
 284 {
 285         dprintk(1, "i2c detach [client=%s]\n", client->name);
 286
 287         return 0;
 288 }
 289
 290 void au0828_call_i2c_clients(struct au0828_dev *dev,
 291                               unsigned int cmd, void *arg)
 292 {
 293         if (dev->i2c_rc != 0)
 294                 return;
 295
 296         i2c_clients_command(&dev->i2c_adap, cmd, arg);
 297 }
 298
 299 static u32 au0828_functionality(struct i2c_adapter *adap)
 300 {
 301         return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C;
 302 }
 303
 304 static struct i2c_algorithm au0828_i2c_algo_template = {
 305         .master_xfer    = i2c_xfer,
 306         .functionality  = au0828_functionality,
 307 };
 308
 309 /* ----------------------------------------------------------------------- */
 310
 311 static struct i2c_adapter au0828_i2c_adap_template = {
 312         .name              = DRIVER_NAME,
 313         .owner             = THIS_MODULE,
 314         .id                = I2C_HW_B_AU0828,
 315         .algo              = &au0828_i2c_algo_template,
 316         .class             = I2C_CLASS_TV_ANALOG,
 317         .client_register   = attach_inform,
 318         .client_unregister = detach_inform,
 319 };
 320
 321 static struct i2c_client au0828_i2c_client_template = {
 322         .name   = "au0828 internal",
 323 };
 324
 325 static char *i2c_devs[128] = {
 326         [ 0x8e >> 1 ] = "au8522",
 327         [ 0xa0 >> 1 ] = "eeprom",
 328         [ 0xc2 >> 1 ] = "tuner/xc5000",
 329 };
 330
 331 static void do_i2c_scan(char *name, struct i2c_client *c)
 332 {
 333         unsigned char buf;
 334         int i, rc;
 335
 336         for (i = 0; i < 128; i++) {
 337                 c->addr = i;
 338                 rc = i2c_master_recv(c, &buf, 0);
 339                 if (rc < 0)
 340                         continue;
 341                 printk("%s: i2c scan: found device @ 0x%x  [%s]\n",
 342                        name, i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
 343         }
 344 }
 345
 346 /* init + register i2c algo-bit adapter */
 347 int au0828_i2c_register(struct au0828_dev *dev)
 348 {
 349         dprintk(1, "%s()\n", __FUNCTION__);
 350
 351         memcpy(&dev->i2c_adap, &au0828_i2c_adap_template,
 352                sizeof(dev->i2c_adap));
 353         memcpy(&dev->i2c_algo, &au0828_i2c_algo_template,
 354                sizeof(dev->i2c_algo));
 355         memcpy(&dev->i2c_client, &au0828_i2c_client_template,
 356                sizeof(dev->i2c_client));
 357
 358         dev->i2c_adap.dev.parent = &dev->usbdev->dev;
 359
 360         strlcpy(dev->i2c_adap.name, DRIVER_NAME,
 361                 sizeof(dev->i2c_adap.name));
 362
 363         dev->i2c_algo.data = dev;
 364         dev->i2c_adap.algo_data = dev;
 365         i2c_set_adapdata(&dev->i2c_adap, dev);
 366         i2c_add_adapter(&dev->i2c_adap);
 367
 368         dev->i2c_client.adapter = &dev->i2c_adap;
 369
 370         if (0 == dev->i2c_rc) {
 371                 printk("%s: i2c bus registered\n", DRIVER_NAME);
 372                 if (i2c_scan)
 373                         do_i2c_scan(DRIVER_NAME, &dev->i2c_client);
 374         } else
 375                 printk("%s: i2c bus register FAILED\n", DRIVER_NAME);
 376
 377         return dev->i2c_rc;
 378 }
 379
 380 int au0828_i2c_unregister(struct au0828_dev *dev)
 381 {
 382         i2c_del_adapter(&dev->i2c_adap);
 383         return 0;
 384 }
 385