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         u8 i2c_speed = dev->board.i2c_clk_divider;
 145
 146         dprintk(4, "%s()\n", __func__);
 147
 148         au0828_write(dev, AU0828_I2C_MULTIBYTE_MODE_2FF, 0x01);
 149
 150         if (((dev->board.tuner_type == TUNER_XC5000) ||
 151              (dev->board.tuner_type == TUNER_XC5000C)) &&
 152             (dev->board.tuner_addr == msg->addr)) {
 153                 /*
 154                  * Due to I2C clock stretch, we need to use a lower speed
 155                  * on xc5000 for commands. However, firmware transfer can
 156                  * speed up to 400 KHz.
 157                  */
 158                 if (msg->len == 64)
 159                         i2c_speed = AU0828_I2C_CLK_250KHZ;
 160                 else
 161                         i2c_speed = AU0828_I2C_CLK_20KHZ;
 162         }
 163         /* Set the I2C clock */
 164         au0828_write(dev, AU0828_I2C_CLK_DIVIDER_202, i2c_speed);
 165
 166         /* Hardware needs 8 bit addresses */
 167         au0828_write(dev, AU0828_I2C_DEST_ADDR_203, msg->addr << 1);
 168
 169         dprintk(4, "SEND: %02x\n", msg->addr);
 170
 171         /* Deal with i2c_scan */
 172         if (msg->len == 0) {
 173                 /* The analog tuner detection code makes use of the SMBUS_QUICK
 174                    message (which involves a zero length i2c write).  To avoid
 175                    checking the status register when we didn't strobe out any
 176                    actual bytes to the bus, just do a read check.  This is
 177                    consistent with how I saw i2c device checking done in the
 178                    USB trace of the Windows driver */
 179                 au0828_write(dev, AU0828_I2C_TRIGGER_200,
 180                              AU0828_I2C_TRIGGER_READ);
 181
 182                 if (!i2c_wait_done(i2c_adap))
 183                         return -EIO;
 184
 185                 if (i2c_wait_read_ack(i2c_adap))
 186                         return -EIO;
 187
 188                 return 0;
 189         }
 190
 191         for (i = 0; i < msg->len;) {
 192
 193                 dprintk(4, " %02x\n", msg->buf[i]);
 194
 195                 au0828_write(dev, AU0828_I2C_WRITE_FIFO_205, msg->buf[i]);
 196
 197                 strobe++;
 198                 i++;
 199
 200                 if ((strobe >= 4) || (i >= msg->len)) {
 201
 202                         /* Strobe the byte into the bus */
 203                         if (i < msg->len)
 204                                 au0828_write(dev, AU0828_I2C_TRIGGER_200,
 205                                              AU0828_I2C_TRIGGER_WRITE |
 206                                              AU0828_I2C_TRIGGER_HOLD);
 207                         else
 208                                 au0828_write(dev, AU0828_I2C_TRIGGER_200,
 209                                              AU0828_I2C_TRIGGER_WRITE);
 210
 211                         /* Reset strobe trigger */
 212                         strobe = 0;
 213
 214                         if (!i2c_wait_write_done(i2c_adap))
 215                                 return -EIO;
 216
 217                 }
 218
 219         }
 220         if (!i2c_wait_done(i2c_adap))
 221                 return -EIO;
 222
 223         dprintk(4, "\n");
 224
 225         return msg->len;
 226 }
 227
 228 /* FIXME: Implement join handling correctly */
 229 static int i2c_readbytes(struct i2c_adapter *i2c_adap,
 230         const struct i2c_msg *msg, int joined)
 231 {
 232         struct au0828_dev *dev = i2c_adap->algo_data;
 233         u8 i2c_speed = dev->board.i2c_clk_divider;
 234         int i;
 235
 236         dprintk(4, "%s()\n", __func__);
 237
 238         au0828_write(dev, AU0828_I2C_MULTIBYTE_MODE_2FF, 0x01);
 239
 240         /*
 241          * Due to xc5000c clock stretch, we cannot use full speed at
 242          * readings from xc5000, as otherwise they'll fail.
 243          */
 244         if (((dev->board.tuner_type == TUNER_XC5000) ||
 245              (dev->board.tuner_type == TUNER_XC5000C)) &&
 246             (dev->board.tuner_addr == msg->addr))
 247                 i2c_speed = AU0828_I2C_CLK_20KHZ;
 248
 249         /* Set the I2C clock */
 250         au0828_write(dev, AU0828_I2C_CLK_DIVIDER_202, i2c_speed);
 251
 252         /* Hardware needs 8 bit addresses */
 253         au0828_write(dev, AU0828_I2C_DEST_ADDR_203, msg->addr << 1);
 254
 255         dprintk(4, " RECV:\n");
 256
 257         /* Deal with i2c_scan */
 258         if (msg->len == 0) {
 259                 au0828_write(dev, AU0828_I2C_TRIGGER_200,
 260                              AU0828_I2C_TRIGGER_READ);
 261
 262                 if (i2c_wait_read_ack(i2c_adap))
 263                         return -EIO;
 264                 return 0;
 265         }
 266
 267         for (i = 0; i < msg->len;) {
 268
 269                 i++;
 270
 271                 if (i < msg->len)
 272                         au0828_write(dev, AU0828_I2C_TRIGGER_200,
 273                                      AU0828_I2C_TRIGGER_READ |
 274                                      AU0828_I2C_TRIGGER_HOLD);
 275                 else
 276                         au0828_write(dev, AU0828_I2C_TRIGGER_200,
 277                                      AU0828_I2C_TRIGGER_READ);
 278
 279                 if (!i2c_wait_read_done(i2c_adap))
 280                         return -EIO;
 281
 282                 msg->buf[i-1] = au0828_read(dev, AU0828_I2C_READ_FIFO_209) &
 283                         0xff;
 284
 285                 dprintk(4, " %02x\n", msg->buf[i-1]);
 286         }
 287         if (!i2c_wait_done(i2c_adap))
 288                 return -EIO;
 289
 290         dprintk(4, "\n");
 291
 292         return msg->len;
 293 }
 294
 295 static int i2c_xfer(struct i2c_adapter *i2c_adap,
 296                     struct i2c_msg *msgs, int num)
 297 {
 298         int i, retval = 0;
 299
 300         dprintk(4, "%s(num = %d)\n", __func__, num);
 301
 302         for (i = 0; i < num; i++) {
 303                 dprintk(4, "%s(num = %d) addr = 0x%02x  len = 0x%x\n",
 304                         __func__, num, msgs[i].addr, msgs[i].len);
 305                 if (msgs[i].flags & I2C_M_RD) {
 306                         /* read */
 307                         retval = i2c_readbytes(i2c_adap, &msgs[i], 0);
 308                 } else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) &&
 309                            msgs[i].addr == msgs[i + 1].addr) {
 310                         /* write then read from same address */
 311                         retval = i2c_sendbytes(i2c_adap, &msgs[i],
 312                                                msgs[i + 1].len);
 313                         if (retval < 0)
 314                                 goto err;
 315                         i++;
 316                         retval = i2c_readbytes(i2c_adap, &msgs[i], 1);
 317                 } else {
 318                         /* write */
 319                         retval = i2c_sendbytes(i2c_adap, &msgs[i], 0);
 320                 }
 321                 if (retval < 0)
 322                         goto err;
 323         }
 324         return num;
 325
 326 err:
 327         return retval;
 328 }
 329
 330 static u32 au0828_functionality(struct i2c_adapter *adap)
 331 {
 332         return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C;
 333 }
 334
 335 static struct i2c_algorithm au0828_i2c_algo_template = {
 336         .master_xfer    = i2c_xfer,
 337         .functionality  = au0828_functionality,
 338 };
 339
 340 /* ----------------------------------------------------------------------- */
 341
 342 static struct i2c_adapter au0828_i2c_adap_template = {
 343         .name              = DRIVER_NAME,
 344         .owner             = THIS_MODULE,
 345         .algo              = &au0828_i2c_algo_template,
 346 };
 347
 348 static struct i2c_client au0828_i2c_client_template = {
 349         .name   = "au0828 internal",
 350 };
 351
 352 static char *i2c_devs[128] = {
 353         [0x8e >> 1] = "au8522",
 354         [0xa0 >> 1] = "eeprom",
 355         [0xc2 >> 1] = "tuner/xc5000",
 356 };
 357
 358 static void do_i2c_scan(char *name, struct i2c_client *c)
 359 {
 360         unsigned char buf;
 361         int i, rc;
 362
 363         for (i = 0; i < 128; i++) {
 364                 c->addr = i;
 365                 rc = i2c_master_recv(c, &buf, 0);
 366                 if (rc < 0)
 367                         continue;
 368                 printk(KERN_INFO "%s: i2c scan: found device @ 0x%x  [%s]\n",
 369                        name, i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
 370         }
 371 }
 372
 373 /* init + register i2c adapter */
 374 int au0828_i2c_register(struct au0828_dev *dev)
 375 {
 376         dprintk(1, "%s()\n", __func__);
 377
 378         dev->i2c_adap = au0828_i2c_adap_template;
 379         dev->i2c_algo = au0828_i2c_algo_template;
 380         dev->i2c_client = au0828_i2c_client_template;
 381
 382         dev->i2c_adap.dev.parent = &dev->usbdev->dev;
 383
 384         strlcpy(dev->i2c_adap.name, DRIVER_NAME,
 385                 sizeof(dev->i2c_adap.name));
 386
 387         dev->i2c_adap.algo = &dev->i2c_algo;
 388         dev->i2c_adap.algo_data = dev;
 389 #ifdef CONFIG_VIDEO_AU0828_V4L2
 390         i2c_set_adapdata(&dev->i2c_adap, &dev->v4l2_dev);
 391 #else
 392         i2c_set_adapdata(&dev->i2c_adap, dev);
 393 #endif
 394         i2c_add_adapter(&dev->i2c_adap);
 395
 396         dev->i2c_client.adapter = &dev->i2c_adap;
 397
 398         if (0 == dev->i2c_rc) {
 399                 printk(KERN_INFO "%s: i2c bus registered\n", DRIVER_NAME);
 400                 if (i2c_scan)
 401                         do_i2c_scan(DRIVER_NAME, &dev->i2c_client);
 402         } else
 403                 printk(KERN_INFO "%s: i2c bus register FAILED\n", DRIVER_NAME);
 404
 405         return dev->i2c_rc;
 406 }
 407
 408 int au0828_i2c_unregister(struct au0828_dev *dev)
 409 {
 410         i2c_del_adapter(&dev->i2c_adap);
 411         return 0;
 412 }
 413