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 /* 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         au0828_write(dev, AU0828_I2C_CLK_DIVIDER_202,
 151                      dev->board.i2c_clk_divider);
 152
 153         /* Hardware needs 8 bit addresses */
 154         au0828_write(dev, AU0828_I2C_DEST_ADDR_203, msg->addr << 1);
 155
 156         dprintk(4, "SEND: %02x\n", msg->addr);
 157
 158         /* Deal with i2c_scan */
 159         if (msg->len == 0) {
 160                 /* The analog tuner detection code makes use of the SMBUS_QUICK
 161                    message (which involves a zero length i2c write).  To avoid
 162                    checking the status register when we didn't strobe out any
 163                    actual bytes to the bus, just do a read check.  This is
 164                    consistent with how I saw i2c device checking done in the
 165                    USB trace of the Windows driver */
 166                 au0828_write(dev, AU0828_I2C_TRIGGER_200,
 167                              AU0828_I2C_TRIGGER_READ);
 168
 169                 if (!i2c_wait_done(i2c_adap))
 170                         return -EIO;
 171
 172                 if (i2c_wait_read_ack(i2c_adap))
 173                         return -EIO;
 174
 175                 return 0;
 176         }
 177
 178         for (i = 0; i < msg->len;) {
 179
 180                 dprintk(4, " %02x\n", msg->buf[i]);
 181
 182                 au0828_write(dev, AU0828_I2C_WRITE_FIFO_205, msg->buf[i]);
 183
 184                 strobe++;
 185                 i++;
 186
 187                 if ((strobe >= 4) || (i >= msg->len)) {
 188
 189                         /* Strobe the byte into the bus */
 190                         if (i < msg->len)
 191                                 au0828_write(dev, AU0828_I2C_TRIGGER_200,
 192                                              AU0828_I2C_TRIGGER_WRITE |
 193                                              AU0828_I2C_TRIGGER_HOLD);
 194                         else
 195                                 au0828_write(dev, AU0828_I2C_TRIGGER_200,
 196                                              AU0828_I2C_TRIGGER_WRITE);
 197
 198                         /* Reset strobe trigger */
 199                         strobe = 0;
 200
 201                         if (!i2c_wait_write_done(i2c_adap))
 202                                 return -EIO;
 203
 204                 }
 205
 206         }
 207         if (!i2c_wait_done(i2c_adap))
 208                 return -EIO;
 209
 210         dprintk(4, "\n");
 211
 212         return msg->len;
 213 }
 214
 215 /* FIXME: Implement join handling correctly */
 216 static int i2c_readbytes(struct i2c_adapter *i2c_adap,
 217         const struct i2c_msg *msg, int joined)
 218 {
 219         struct au0828_dev *dev = i2c_adap->algo_data;
 220         int i;
 221
 222         dprintk(4, "%s()\n", __func__);
 223
 224         au0828_write(dev, AU0828_I2C_MULTIBYTE_MODE_2FF, 0x01);
 225
 226         /* Set the I2C clock */
 227         au0828_write(dev, AU0828_I2C_CLK_DIVIDER_202,
 228                      dev->board.i2c_clk_divider);
 229
 230         /* Hardware needs 8 bit addresses */
 231         au0828_write(dev, AU0828_I2C_DEST_ADDR_203, msg->addr << 1);
 232
 233         dprintk(4, " RECV:\n");
 234
 235         /* Deal with i2c_scan */
 236         if (msg->len == 0) {
 237                 au0828_write(dev, AU0828_I2C_TRIGGER_200,
 238                              AU0828_I2C_TRIGGER_READ);
 239
 240                 if (i2c_wait_read_ack(i2c_adap))
 241                         return -EIO;
 242                 return 0;
 243         }
 244
 245         for (i = 0; i < msg->len;) {
 246
 247                 i++;
 248
 249                 if (i < msg->len)
 250                         au0828_write(dev, AU0828_I2C_TRIGGER_200,
 251                                      AU0828_I2C_TRIGGER_READ |
 252                                      AU0828_I2C_TRIGGER_HOLD);
 253                 else
 254                         au0828_write(dev, AU0828_I2C_TRIGGER_200,
 255                                      AU0828_I2C_TRIGGER_READ);
 256
 257                 if (!i2c_wait_read_done(i2c_adap))
 258                         return -EIO;
 259
 260                 msg->buf[i-1] = au0828_read(dev, AU0828_I2C_READ_FIFO_209) &
 261                         0xff;
 262
 263                 dprintk(4, " %02x\n", msg->buf[i-1]);
 264         }
 265         if (!i2c_wait_done(i2c_adap))
 266                 return -EIO;
 267
 268         dprintk(4, "\n");
 269
 270         return msg->len;
 271 }
 272
 273 static int i2c_xfer(struct i2c_adapter *i2c_adap,
 274                     struct i2c_msg *msgs, int num)
 275 {
 276         int i, retval = 0;
 277
 278         dprintk(4, "%s(num = %d)\n", __func__, num);
 279
 280         for (i = 0; i < num; i++) {
 281                 dprintk(4, "%s(num = %d) addr = 0x%02x  len = 0x%x\n",
 282                         __func__, num, msgs[i].addr, msgs[i].len);
 283                 if (msgs[i].flags & I2C_M_RD) {
 284                         /* read */
 285                         retval = i2c_readbytes(i2c_adap, &msgs[i], 0);
 286                 } else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) &&
 287                            msgs[i].addr == msgs[i + 1].addr) {
 288                         /* write then read from same address */
 289                         retval = i2c_sendbytes(i2c_adap, &msgs[i],
 290                                                msgs[i + 1].len);
 291                         if (retval < 0)
 292                                 goto err;
 293                         i++;
 294                         retval = i2c_readbytes(i2c_adap, &msgs[i], 1);
 295                 } else {
 296                         /* write */
 297                         retval = i2c_sendbytes(i2c_adap, &msgs[i], 0);
 298                 }
 299                 if (retval < 0)
 300                         goto err;
 301         }
 302         return num;
 303
 304 err:
 305         return retval;
 306 }
 307
 308 static u32 au0828_functionality(struct i2c_adapter *adap)
 309 {
 310         return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C;
 311 }
 312
 313 static struct i2c_algorithm au0828_i2c_algo_template = {
 314         .master_xfer    = i2c_xfer,
 315         .functionality  = au0828_functionality,
 316 };
 317
 318 /* ----------------------------------------------------------------------- */
 319
 320 static struct i2c_adapter au0828_i2c_adap_template = {
 321         .name              = DRIVER_NAME,
 322         .owner             = THIS_MODULE,
 323         .id                = I2C_HW_B_AU0828,
 324         .algo              = &au0828_i2c_algo_template,
 325 };
 326
 327 static struct i2c_client au0828_i2c_client_template = {
 328         .name   = "au0828 internal",
 329 };
 330
 331 static char *i2c_devs[128] = {
 332         [0x8e >> 1] = "au8522",
 333         [0xa0 >> 1] = "eeprom",
 334         [0xc2 >> 1] = "tuner/xc5000",
 335 };
 336
 337 static void do_i2c_scan(char *name, struct i2c_client *c)
 338 {
 339         unsigned char buf;
 340         int i, rc;
 341
 342         for (i = 0; i < 128; i++) {
 343                 c->addr = i;
 344                 rc = i2c_master_recv(c, &buf, 0);
 345                 if (rc < 0)
 346                         continue;
 347                 printk(KERN_INFO "%s: i2c scan: found device @ 0x%x  [%s]\n",
 348                        name, i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
 349         }
 350 }
 351
 352 /* init + register i2c algo-bit adapter */
 353 int au0828_i2c_register(struct au0828_dev *dev)
 354 {
 355         dprintk(1, "%s()\n", __func__);
 356
 357         memcpy(&dev->i2c_adap, &au0828_i2c_adap_template,
 358                sizeof(dev->i2c_adap));
 359         memcpy(&dev->i2c_algo, &au0828_i2c_algo_template,
 360                sizeof(dev->i2c_algo));
 361         memcpy(&dev->i2c_client, &au0828_i2c_client_template,
 362                sizeof(dev->i2c_client));
 363
 364         dev->i2c_adap.dev.parent = &dev->usbdev->dev;
 365
 366         strlcpy(dev->i2c_adap.name, DRIVER_NAME,
 367                 sizeof(dev->i2c_adap.name));
 368
 369         dev->i2c_adap.algo = &dev->i2c_algo;
 370         dev->i2c_adap.algo_data = dev;
 371         i2c_set_adapdata(&dev->i2c_adap, &dev->v4l2_dev);
 372         i2c_add_adapter(&dev->i2c_adap);
 373
 374         dev->i2c_client.adapter = &dev->i2c_adap;
 375
 376         if (0 == dev->i2c_rc) {
 377                 printk(KERN_INFO "%s: i2c bus registered\n", DRIVER_NAME);
 378                 if (i2c_scan)
 379                         do_i2c_scan(DRIVER_NAME, &dev->i2c_client);
 380         } else
 381                 printk(KERN_INFO "%s: i2c bus register FAILED\n", DRIVER_NAME);
 382
 383         return dev->i2c_rc;
 384 }
 385
 386 int au0828_i2c_unregister(struct au0828_dev *dev)
 387 {
 388         i2c_del_adapter(&dev->i2c_adap);
 389         return 0;
 390 }
 391