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, REG_201) & 0x08 ? 0 : 1;
  43 }
  44
  45 static inline int i2c_slave_did_read_ack(struct i2c_adapter *i2c_adap)
  46 {
  47         struct au0828_dev *dev = i2c_adap->algo_data;
  48         return au0828_read(dev, REG_201) & 0x02 ? 0 : 1;
  49 }
  50
  51 static int i2c_wait_read_ack(struct i2c_adapter *i2c_adap)
  52 {
  53         int count;
  54
  55         for (count = 0; count < I2C_WAIT_RETRY; count++) {
  56                 if (!i2c_slave_did_read_ack(i2c_adap))
  57                         break;
  58                 udelay(I2C_WAIT_DELAY);
  59         }
  60
  61         if (I2C_WAIT_RETRY == count)
  62                 return 0;
  63
  64         return 1;
  65 }
  66
  67 static inline int i2c_is_read_busy(struct i2c_adapter *i2c_adap)
  68 {
  69         struct au0828_dev *dev = i2c_adap->algo_data;
  70         return au0828_read(dev, REG_201) & 0x01 ? 0 : 1;
  71 }
  72
  73 static int i2c_wait_read_done(struct i2c_adapter *i2c_adap)
  74 {
  75         int count;
  76
  77         for (count = 0; count < I2C_WAIT_RETRY; count++) {
  78                 if (!i2c_is_read_busy(i2c_adap))
  79                         break;
  80                 udelay(I2C_WAIT_DELAY);
  81         }
  82
  83         if (I2C_WAIT_RETRY == count)
  84                 return 0;
  85
  86         return 1;
  87 }
  88
  89 static inline int i2c_is_write_done(struct i2c_adapter *i2c_adap)
  90 {
  91         struct au0828_dev *dev = i2c_adap->algo_data;
  92         return au0828_read(dev, REG_201) & 0x04 ? 1 : 0;
  93 }
  94
  95 static int i2c_wait_write_done(struct i2c_adapter *i2c_adap)
  96 {
  97         int count;
  98
  99         for (count = 0; count < I2C_WAIT_RETRY; count++) {
 100                 if (i2c_is_write_done(i2c_adap))
 101                         break;
 102                 udelay(I2C_WAIT_DELAY);
 103         }
 104
 105         if (I2C_WAIT_RETRY == count)
 106                 return 0;
 107
 108         return 1;
 109 }
 110
 111 static inline int i2c_is_busy(struct i2c_adapter *i2c_adap)
 112 {
 113         struct au0828_dev *dev = i2c_adap->algo_data;
 114         return au0828_read(dev, REG_201) & 0x10 ? 1 : 0;
 115 }
 116
 117 static int i2c_wait_done(struct i2c_adapter *i2c_adap)
 118 {
 119         int count;
 120
 121         for (count = 0; count < I2C_WAIT_RETRY; count++) {
 122                 if (!i2c_is_busy(i2c_adap))
 123                         break;
 124                 udelay(I2C_WAIT_DELAY);
 125         }
 126
 127         if (I2C_WAIT_RETRY == count)
 128                 return 0;
 129
 130         return 1;
 131 }
 132
 133 /* FIXME: Implement join handling correctly */
 134 static int i2c_sendbytes(struct i2c_adapter *i2c_adap,
 135         const struct i2c_msg *msg, int joined_rlen)
 136 {
 137         int i, strobe = 0;
 138         struct au0828_dev *dev = i2c_adap->algo_data;
 139
 140         dprintk(4, "%s()\n", __func__);
 141
 142         au0828_write(dev, REG_2FF, 0x01);
 143
 144         /* FIXME: There is a problem with i2c communications with xc5000 that
 145            requires us to slow down the i2c clock until we have a better
 146            strategy (such as using the secondary i2c bus to do firmware
 147            loading */
 148         if ((msg->addr << 1) == 0xc2) {
 149                 au0828_write(dev, REG_202, 0x40);
 150         } else {
 151                 au0828_write(dev, REG_202, 0x07);
 152         }
 153
 154         /* Hardware needs 8 bit addresses */
 155         au0828_write(dev, REG_203, msg->addr << 1);
 156
 157         dprintk(4, "SEND: %02x\n", msg->addr);
 158
 159         for (i = 0; i < msg->len;) {
 160
 161                 dprintk(4, " %02x\n", msg->buf[i]);
 162
 163                 au0828_write(dev, REG_205, msg->buf[i]);
 164
 165                 strobe++;
 166                 i++;
 167
 168                 if ((strobe >= 4) || (i >= msg->len)) {
 169
 170                         /* Strobe the byte into the bus */
 171                         if (i < msg->len)
 172                                 au0828_write(dev, REG_200, 0x41);
 173                         else
 174                                 au0828_write(dev, REG_200, 0x01);
 175
 176                         /* Reset strobe trigger */
 177                         strobe = 0;
 178
 179                         if (!i2c_wait_write_done(i2c_adap))
 180                                 return -EIO;
 181
 182                 }
 183
 184         }
 185         if (!i2c_wait_done(i2c_adap))
 186                 return -EIO;
 187
 188         dprintk(4, "\n");
 189
 190         return msg->len;
 191 }
 192
 193 /* FIXME: Implement join handling correctly */
 194 static int i2c_readbytes(struct i2c_adapter *i2c_adap,
 195         const struct i2c_msg *msg, int joined)
 196 {
 197         struct au0828_dev *dev = i2c_adap->algo_data;
 198         int i;
 199
 200         dprintk(4, "%s()\n", __func__);
 201
 202         au0828_write(dev, REG_2FF, 0x01);
 203
 204         /* FIXME: There is a problem with i2c communications with xc5000 that
 205            requires us to slow down the i2c clock until we have a better
 206            strategy (such as using the secondary i2c bus to do firmware
 207            loading */
 208         if ((msg->addr << 1) == 0xc2) {
 209                 au0828_write(dev, REG_202, 0x40);
 210         } else {
 211                 au0828_write(dev, REG_202, 0x07);
 212         }
 213
 214         /* Hardware needs 8 bit addresses */
 215         au0828_write(dev, REG_203, msg->addr << 1);
 216
 217         dprintk(4, " RECV:\n");
 218
 219         /* Deal with i2c_scan */
 220         if (msg->len == 0) {
 221                 au0828_write(dev, REG_200, 0x20);
 222                 if (i2c_wait_read_ack(i2c_adap))
 223                         return -EIO;
 224                 return 0;
 225         }
 226
 227         for (i = 0; i < msg->len;) {
 228
 229                 i++;
 230
 231                 if (i < msg->len)
 232                         au0828_write(dev, REG_200, 0x60);
 233                 else
 234                         au0828_write(dev, REG_200, 0x20);
 235
 236                 if (!i2c_wait_read_done(i2c_adap))
 237                         return -EIO;
 238
 239                 msg->buf[i-1] = au0828_read(dev, REG_209) & 0xff;
 240
 241                 dprintk(4, " %02x\n", msg->buf[i-1]);
 242         }
 243         if (!i2c_wait_done(i2c_adap))
 244                 return -EIO;
 245
 246         dprintk(4, "\n");
 247
 248         return msg->len;
 249 }
 250
 251 static int i2c_xfer(struct i2c_adapter *i2c_adap,
 252                     struct i2c_msg *msgs, int num)
 253 {
 254         int i, retval = 0;
 255
 256         dprintk(4, "%s(num = %d)\n", __func__, num);
 257
 258         for (i = 0; i < num; i++) {
 259                 dprintk(4, "%s(num = %d) addr = 0x%02x  len = 0x%x\n",
 260                         __func__, num, msgs[i].addr, msgs[i].len);
 261                 if (msgs[i].flags & I2C_M_RD) {
 262                         /* read */
 263                         retval = i2c_readbytes(i2c_adap, &msgs[i], 0);
 264                 } else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) &&
 265                            msgs[i].addr == msgs[i + 1].addr) {
 266                         /* write then read from same address */
 267                         retval = i2c_sendbytes(i2c_adap, &msgs[i],
 268                                                msgs[i + 1].len);
 269                         if (retval < 0)
 270                                 goto err;
 271                         i++;
 272                         retval = i2c_readbytes(i2c_adap, &msgs[i], 1);
 273                 } else {
 274                         /* write */
 275                         retval = i2c_sendbytes(i2c_adap, &msgs[i], 0);
 276                 }
 277                 if (retval < 0)
 278                         goto err;
 279         }
 280         return num;
 281
 282 err:
 283         return retval;
 284 }
 285
 286 static int attach_inform(struct i2c_client *client)
 287 {
 288         dprintk(1, "%s i2c attach [addr=0x%x,client=%s]\n",
 289                 client->driver->driver.name, client->addr, client->name);
 290
 291         if (!client->driver->command)
 292                 return 0;
 293
 294         return 0;
 295 }
 296
 297 static int detach_inform(struct i2c_client *client)
 298 {
 299         dprintk(1, "i2c detach [client=%s]\n", client->name);
 300
 301         return 0;
 302 }
 303
 304 void au0828_call_i2c_clients(struct au0828_dev *dev,
 305                               unsigned int cmd, void *arg)
 306 {
 307         if (dev->i2c_rc != 0)
 308                 return;
 309
 310         i2c_clients_command(&dev->i2c_adap, cmd, arg);
 311 }
 312
 313 static u32 au0828_functionality(struct i2c_adapter *adap)
 314 {
 315         return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C;
 316 }
 317
 318 static struct i2c_algorithm au0828_i2c_algo_template = {
 319         .master_xfer    = i2c_xfer,
 320         .functionality  = au0828_functionality,
 321 };
 322
 323 /* ----------------------------------------------------------------------- */
 324
 325 static struct i2c_adapter au0828_i2c_adap_template = {
 326         .name              = DRIVER_NAME,
 327         .owner             = THIS_MODULE,
 328         .id                = I2C_HW_B_AU0828,
 329         .algo              = &au0828_i2c_algo_template,
 330         .class             = I2C_CLASS_TV_ANALOG,
 331         .client_register   = attach_inform,
 332         .client_unregister = detach_inform,
 333 };
 334
 335 static struct i2c_client au0828_i2c_client_template = {
 336         .name   = "au0828 internal",
 337 };
 338
 339 static char *i2c_devs[128] = {
 340         [0x8e >> 1] = "au8522",
 341         [0xa0 >> 1] = "eeprom",
 342         [0xc2 >> 1] = "tuner/xc5000",
 343 };
 344
 345 static void do_i2c_scan(char *name, struct i2c_client *c)
 346 {
 347         unsigned char buf;
 348         int i, rc;
 349
 350         for (i = 0; i < 128; i++) {
 351                 c->addr = i;
 352                 rc = i2c_master_recv(c, &buf, 0);
 353                 if (rc < 0)
 354                         continue;
 355                 printk(KERN_INFO "%s: i2c scan: found device @ 0x%x  [%s]\n",
 356                        name, i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
 357         }
 358 }
 359
 360 /* init + register i2c algo-bit adapter */
 361 int au0828_i2c_register(struct au0828_dev *dev)
 362 {
 363         dprintk(1, "%s()\n", __func__);
 364
 365         memcpy(&dev->i2c_adap, &au0828_i2c_adap_template,
 366                sizeof(dev->i2c_adap));
 367         memcpy(&dev->i2c_algo, &au0828_i2c_algo_template,
 368                sizeof(dev->i2c_algo));
 369         memcpy(&dev->i2c_client, &au0828_i2c_client_template,
 370                sizeof(dev->i2c_client));
 371
 372         dev->i2c_adap.dev.parent = &dev->usbdev->dev;
 373
 374         strlcpy(dev->i2c_adap.name, DRIVER_NAME,
 375                 sizeof(dev->i2c_adap.name));
 376
 377         dev->i2c_algo.data = dev;
 378         dev->i2c_adap.algo_data = dev;
 379         i2c_set_adapdata(&dev->i2c_adap, dev);
 380         i2c_add_adapter(&dev->i2c_adap);
 381
 382         dev->i2c_client.adapter = &dev->i2c_adap;
 383
 384         if (0 == dev->i2c_rc) {
 385                 printk(KERN_INFO "%s: i2c bus registered\n", DRIVER_NAME);
 386                 if (i2c_scan)
 387                         do_i2c_scan(DRIVER_NAME, &dev->i2c_client);
 388         } else
 389                 printk(KERN_INFO "%s: i2c bus register FAILED\n", DRIVER_NAME);
 390
 391         return dev->i2c_rc;
 392 }
 393
 394 int au0828_i2c_unregister(struct au0828_dev *dev)
 395 {
 396         i2c_del_adapter(&dev->i2c_adap);
 397         return 0;
 398 }
 399