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 <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 #include "media/tuner.h"
  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 25
  37 #define I2C_WAIT_RETRY 1000
  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 /* FIXME: Implement join handling correctly */
 139 static int i2c_sendbytes(struct i2c_adapter *i2c_adap,
 140         const struct i2c_msg *msg, int joined_rlen)
 141 {
 142         int i, strobe = 0;
 143         struct au0828_dev *dev = i2c_adap->algo_data;
 144
 145         dprintk(4, "%s()\n", __func__);
 146
 147         au0828_write(dev, AU0828_I2C_MULTIBYTE_MODE_2FF, 0x01);
 148
 149         /* Set the I2C clock */
 150         if (((dev->board.tuner_type == TUNER_XC5000) ||
 151              (dev->board.tuner_type == TUNER_XC5000C)) &&
 152             (dev->board.tuner_addr == msg->addr) &&
 153             (msg->len == 64)) {
 154                 /* Hack to speed up firmware load.  The xc5000 lets us do up
 155                    to 400 KHz when in firmware download mode */
 156                 au0828_write(dev, AU0828_I2C_CLK_DIVIDER_202,
 157                              AU0828_I2C_CLK_250KHZ);
 158         } else {
 159                 /* Use the i2c clock speed in the board configuration */
 160                 au0828_write(dev, AU0828_I2C_CLK_DIVIDER_202,
 161                              dev->board.i2c_clk_divider);
 162         }
 163
 164         /* Hardware needs 8 bit addresses */
 165         au0828_write(dev, AU0828_I2C_DEST_ADDR_203, msg->addr << 1);
 166
 167         dprintk(4, "SEND: %02x\n", msg->addr);
 168
 169         /* Deal with i2c_scan */
 170         if (msg->len == 0) {
 171                 /* The analog tuner detection code makes use of the SMBUS_QUICK
 172                    message (which involves a zero length i2c write).  To avoid
 173                    checking the status register when we didn't strobe out any
 174                    actual bytes to the bus, just do a read check.  This is
 175                    consistent with how I saw i2c device checking done in the
 176                    USB trace of the Windows driver */
 177                 au0828_write(dev, AU0828_I2C_TRIGGER_200,
 178                              AU0828_I2C_TRIGGER_READ);
 179
 180                 if (!i2c_wait_done(i2c_adap))
 181                         return -EIO;
 182
 183                 if (i2c_wait_read_ack(i2c_adap))
 184                         return -EIO;
 185
 186                 return 0;
 187         }
 188
 189         for (i = 0; i < msg->len;) {
 190
 191                 dprintk(4, " %02x\n", msg->buf[i]);
 192
 193                 au0828_write(dev, AU0828_I2C_WRITE_FIFO_205, msg->buf[i]);
 194
 195                 strobe++;
 196                 i++;
 197
 198                 if ((strobe >= 4) || (i >= msg->len)) {
 199
 200                         /* Strobe the byte into the bus */
 201                         if (i < msg->len)
 202                                 au0828_write(dev, AU0828_I2C_TRIGGER_200,
 203                                              AU0828_I2C_TRIGGER_WRITE |
 204                                              AU0828_I2C_TRIGGER_HOLD);
 205                         else
 206                                 au0828_write(dev, AU0828_I2C_TRIGGER_200,
 207                                              AU0828_I2C_TRIGGER_WRITE);
 208
 209                         /* Reset strobe trigger */
 210                         strobe = 0;
 211
 212                         if (!i2c_wait_write_done(i2c_adap))
 213                                 return -EIO;
 214
 215                 }
 216
 217         }
 218         if (!i2c_wait_done(i2c_adap))
 219                 return -EIO;
 220
 221         dprintk(4, "\n");
 222
 223         return msg->len;
 224 }
 225
 226 /* FIXME: Implement join handling correctly */
 227 static int i2c_readbytes(struct i2c_adapter *i2c_adap,
 228         const struct i2c_msg *msg, int joined)
 229 {
 230         struct au0828_dev *dev = i2c_adap->algo_data;
 231         int i;
 232
 233         dprintk(4, "%s()\n", __func__);
 234
 235         au0828_write(dev, AU0828_I2C_MULTIBYTE_MODE_2FF, 0x01);
 236
 237         /* Set the I2C clock */
 238         au0828_write(dev, AU0828_I2C_CLK_DIVIDER_202,
 239                      dev->board.i2c_clk_divider);
 240
 241         /* Hardware needs 8 bit addresses */
 242         au0828_write(dev, AU0828_I2C_DEST_ADDR_203, msg->addr << 1);
 243
 244         dprintk(4, " RECV:\n");
 245
 246         /* Deal with i2c_scan */
 247         if (msg->len == 0) {
 248                 au0828_write(dev, AU0828_I2C_TRIGGER_200,
 249                              AU0828_I2C_TRIGGER_READ);
 250
 251                 if (i2c_wait_read_ack(i2c_adap))
 252                         return -EIO;
 253                 return 0;
 254         }
 255
 256         for (i = 0; i < msg->len;) {
 257
 258                 i++;
 259
 260                 if (i < msg->len)
 261                         au0828_write(dev, AU0828_I2C_TRIGGER_200,
 262                                      AU0828_I2C_TRIGGER_READ |
 263                                      AU0828_I2C_TRIGGER_HOLD);
 264                 else
 265                         au0828_write(dev, AU0828_I2C_TRIGGER_200,
 266                                      AU0828_I2C_TRIGGER_READ);
 267
 268                 if (!i2c_wait_read_done(i2c_adap))
 269                         return -EIO;
 270
 271                 msg->buf[i-1] = au0828_read(dev, AU0828_I2C_READ_FIFO_209) &
 272                         0xff;
 273
 274                 dprintk(4, " %02x\n", msg->buf[i-1]);
 275         }
 276         if (!i2c_wait_done(i2c_adap))
 277                 return -EIO;
 278
 279         dprintk(4, "\n");
 280
 281         return msg->len;
 282 }
 283
 284 static int i2c_xfer(struct i2c_adapter *i2c_adap,
 285                     struct i2c_msg *msgs, int num)
 286 {
 287         int i, retval = 0;
 288
 289         dprintk(4, "%s(num = %d)\n", __func__, num);
 290
 291         for (i = 0; i < num; i++) {
 292                 dprintk(4, "%s(num = %d) addr = 0x%02x  len = 0x%x\n",
 293                         __func__, num, msgs[i].addr, msgs[i].len);
 294                 if (msgs[i].flags & I2C_M_RD) {
 295                         /* read */
 296                         retval = i2c_readbytes(i2c_adap, &msgs[i], 0);
 297                 } else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) &&
 298                            msgs[i].addr == msgs[i + 1].addr) {
 299                         /* write then read from same address */
 300                         retval = i2c_sendbytes(i2c_adap, &msgs[i],
 301                                                msgs[i + 1].len);
 302                         if (retval < 0)
 303                                 goto err;
 304                         i++;
 305                         retval = i2c_readbytes(i2c_adap, &msgs[i], 1);
 306                 } else {
 307                         /* write */
 308                         retval = i2c_sendbytes(i2c_adap, &msgs[i], 0);
 309                 }
 310                 if (retval < 0)
 311                         goto err;
 312         }
 313         return num;
 314
 315 err:
 316         return retval;
 317 }
 318
 319 static u32 au0828_functionality(struct i2c_adapter *adap)
 320 {
 321         return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C;
 322 }
 323
 324 static struct i2c_algorithm au0828_i2c_algo_template = {
 325         .master_xfer    = i2c_xfer,
 326         .functionality  = au0828_functionality,
 327 };
 328
 329 /* ----------------------------------------------------------------------- */
 330
 331 static struct i2c_adapter au0828_i2c_adap_template = {
 332         .name              = DRIVER_NAME,
 333         .owner             = THIS_MODULE,
 334         .algo              = &au0828_i2c_algo_template,
 335 };
 336
 337 static struct i2c_client au0828_i2c_client_template = {
 338         .name   = "au0828 internal",
 339 };
 340
 341 static char *i2c_devs[128] = {
 342         [0x8e >> 1] = "au8522",
 343         [0xa0 >> 1] = "eeprom",
 344         [0xc2 >> 1] = "tuner/xc5000",
 345 };
 346
 347 static void do_i2c_scan(char *name, struct i2c_client *c)
 348 {
 349         unsigned char buf;
 350         int i, rc;
 351
 352         for (i = 0; i < 128; i++) {
 353                 c->addr = i;
 354                 rc = i2c_master_recv(c, &buf, 0);
 355                 if (rc < 0)
 356                         continue;
 357                 printk(KERN_INFO "%s: i2c scan: found device @ 0x%x  [%s]\n",
 358                        name, i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
 359         }
 360 }
 361
 362 /* init + register i2c adapter */
 363 int au0828_i2c_register(struct au0828_dev *dev)
 364 {
 365         dprintk(1, "%s()\n", __func__);
 366
 367         dev->i2c_adap = au0828_i2c_adap_template;
 368         dev->i2c_algo = au0828_i2c_algo_template;
 369         dev->i2c_client = au0828_i2c_client_template;
 370
 371         dev->i2c_adap.dev.parent = &dev->usbdev->dev;
 372
 373         strlcpy(dev->i2c_adap.name, DRIVER_NAME,
 374                 sizeof(dev->i2c_adap.name));
 375
 376         dev->i2c_adap.algo = &dev->i2c_algo;
 377         dev->i2c_adap.algo_data = dev;
 378 #ifdef CONFIG_VIDEO_AU0828_V4L2
 379         i2c_set_adapdata(&dev->i2c_adap, &dev->v4l2_dev);
 380 #else
 381         i2c_set_adapdata(&dev->i2c_adap, dev);
 382 #endif
 383         i2c_add_adapter(&dev->i2c_adap);
 384
 385         dev->i2c_client.adapter = &dev->i2c_adap;
 386
 387         if (0 == dev->i2c_rc) {
 388                 printk(KERN_INFO "%s: i2c bus registered\n", DRIVER_NAME);
 389                 if (i2c_scan)
 390                         do_i2c_scan(DRIVER_NAME, &dev->i2c_client);
 391         } else
 392                 printk(KERN_INFO "%s: i2c bus register FAILED\n", DRIVER_NAME);
 393
 394         return dev->i2c_rc;
 395 }
 396
 397 int au0828_i2c_unregister(struct au0828_dev *dev)
 398 {
 399         i2c_del_adapter(&dev->i2c_adap);
 400         return 0;
 401 }
 402