drivers/media/pci/saa7134/saa7134-i2c.c

   1 /*
   2  *
   3  * device driver for philips saa7134 based TV cards
   4  * i2c interface support
   5  *
   6  * (c) 2001,02 Gerd Knorr <kraxel@bytesex.org> [SuSE Labs]
   7  *
   8  *  This program is free software; you can redistribute it and/or modify
   9  *  it under the terms of the GNU General Public License as published by
  10  *  the Free Software Foundation; either version 2 of the License, or
  11  *  (at your option) any later version.
  12  *
  13  *  This program is distributed in the hope that it will be useful,
  14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  *  GNU General Public License for more details.
  17  */
  18
  19 #include "saa7134.h"
  20 #include "saa7134-reg.h"
  21
  22 #include <linux/init.h>
  23 #include <linux/list.h>
  24 #include <linux/module.h>
  25 #include <linux/kernel.h>
  26 #include <linux/delay.h>
  27
  28 #include <media/v4l2-common.h>
  29
  30 /* ----------------------------------------------------------- */
  31
  32 static unsigned int i2c_debug;
  33 module_param(i2c_debug, int, 0644);
  34 MODULE_PARM_DESC(i2c_debug,"enable debug messages [i2c]");
  35
  36 static unsigned int i2c_scan;
  37 module_param(i2c_scan, int, 0444);
  38 MODULE_PARM_DESC(i2c_scan,"scan i2c bus at insmod time");
  39
  40 #define i2c_dbg(level, fmt, arg...) do { \
  41         if (i2c_debug == level) \
  42                 printk(KERN_DEBUG pr_fmt("i2c: " fmt), ## arg); \
  43         } while (0)
  44
  45 #define i2c_cont(level, fmt, arg...) do { \
  46         if (i2c_debug == level) \
  47                 pr_cont(fmt, ## arg); \
  48         } while (0)
  49
  50 #define I2C_WAIT_DELAY  32
  51 #define I2C_WAIT_RETRY  16
  52
  53 /* ----------------------------------------------------------- */
  54
  55 static char *str_i2c_status[] = {
  56         "IDLE", "DONE_STOP", "BUSY", "TO_SCL", "TO_ARB", "DONE_WRITE",
  57         "DONE_READ", "DONE_WRITE_TO", "DONE_READ_TO", "NO_DEVICE",
  58         "NO_ACKN", "BUS_ERR", "ARB_LOST", "SEQ_ERR", "ST_ERR", "SW_ERR"
  59 };
  60
  61 enum i2c_status {
  62         IDLE          = 0,  // no I2C command pending
  63         DONE_STOP     = 1,  // I2C command done and STOP executed
  64         BUSY          = 2,  // executing I2C command
  65         TO_SCL        = 3,  // executing I2C command, time out on clock stretching
  66         TO_ARB        = 4,  // time out on arbitration trial, still trying
  67         DONE_WRITE    = 5,  // I2C command done and awaiting next write command
  68         DONE_READ     = 6,  // I2C command done and awaiting next read command
  69         DONE_WRITE_TO = 7,  // see 5, and time out on status echo
  70         DONE_READ_TO  = 8,  // see 6, and time out on status echo
  71         NO_DEVICE     = 9,  // no acknowledge on device slave address
  72         NO_ACKN       = 10, // no acknowledge after data byte transfer
  73         BUS_ERR       = 11, // bus error
  74         ARB_LOST      = 12, // arbitration lost during transfer
  75         SEQ_ERR       = 13, // erroneous programming sequence
  76         ST_ERR        = 14, // wrong status echoing
  77         SW_ERR        = 15  // software error
  78 };
  79
  80 static char *str_i2c_attr[] = {
  81         "NOP", "STOP", "CONTINUE", "START"
  82 };
  83
  84 enum i2c_attr {
  85         NOP           = 0,  // no operation on I2C bus
  86         STOP          = 1,  // stop condition, no associated byte transfer
  87         CONTINUE      = 2,  // continue with byte transfer
  88         START         = 3   // start condition with byte transfer
  89 };
  90
  91 static inline enum i2c_status i2c_get_status(struct saa7134_dev *dev)
  92 {
  93         enum i2c_status status;
  94
  95         status = saa_readb(SAA7134_I2C_ATTR_STATUS) & 0x0f;
  96         i2c_dbg(2, "i2c stat <= %s\n", str_i2c_status[status]);
  97         return status;
  98 }
  99
 100 static inline void i2c_set_status(struct saa7134_dev *dev,
 101                                   enum i2c_status status)
 102 {
 103         i2c_dbg(2, "i2c stat => %s\n", str_i2c_status[status]);
 104         saa_andorb(SAA7134_I2C_ATTR_STATUS,0x0f,status);
 105 }
 106
 107 static inline void i2c_set_attr(struct saa7134_dev *dev, enum i2c_attr attr)
 108 {
 109         i2c_dbg(2, "i2c attr => %s\n", str_i2c_attr[attr]);
 110         saa_andorb(SAA7134_I2C_ATTR_STATUS,0xc0,attr << 6);
 111 }
 112
 113 static inline int i2c_is_error(enum i2c_status status)
 114 {
 115         switch (status) {
 116         case NO_DEVICE:
 117         case NO_ACKN:
 118         case BUS_ERR:
 119         case ARB_LOST:
 120         case SEQ_ERR:
 121         case ST_ERR:
 122                 return true;
 123         default:
 124                 return false;
 125         }
 126 }
 127
 128 static inline int i2c_is_idle(enum i2c_status status)
 129 {
 130         switch (status) {
 131         case IDLE:
 132         case DONE_STOP:
 133                 return true;
 134         default:
 135                 return false;
 136         }
 137 }
 138
 139 static inline int i2c_is_busy(enum i2c_status status)
 140 {
 141         switch (status) {
 142         case BUSY:
 143         case TO_SCL:
 144         case TO_ARB:
 145                 return true;
 146         default:
 147                 return false;
 148         }
 149 }
 150
 151 static int i2c_is_busy_wait(struct saa7134_dev *dev)
 152 {
 153         enum i2c_status status;
 154         int count;
 155
 156         for (count = 0; count < I2C_WAIT_RETRY; count++) {
 157                 status = i2c_get_status(dev);
 158                 if (!i2c_is_busy(status))
 159                         break;
 160                 saa_wait(I2C_WAIT_DELAY);
 161         }
 162         if (I2C_WAIT_RETRY == count)
 163                 return false;
 164         return true;
 165 }
 166
 167 static int i2c_reset(struct saa7134_dev *dev)
 168 {
 169         enum i2c_status status;
 170         int count;
 171
 172         i2c_dbg(2, "i2c reset\n");
 173         status = i2c_get_status(dev);
 174         if (!i2c_is_error(status))
 175                 return true;
 176         i2c_set_status(dev,status);
 177
 178         for (count = 0; count < I2C_WAIT_RETRY; count++) {
 179                 status = i2c_get_status(dev);
 180                 if (!i2c_is_error(status))
 181                         break;
 182                 udelay(I2C_WAIT_DELAY);
 183         }
 184         if (I2C_WAIT_RETRY == count)
 185                 return false;
 186
 187         if (!i2c_is_idle(status))
 188                 return false;
 189
 190         i2c_set_attr(dev,NOP);
 191         return true;
 192 }
 193
 194 static inline int i2c_send_byte(struct saa7134_dev *dev,
 195                                 enum i2c_attr attr,
 196                                 unsigned char data)
 197 {
 198         enum i2c_status status;
 199         __u32 dword;
 200
 201         /* have to write both attr + data in one 32bit word */
 202         dword  = saa_readl(SAA7134_I2C_ATTR_STATUS >> 2);
 203         dword &= 0x0f;
 204         dword |= (attr << 6);
 205         dword |= ((__u32)data << 8);
 206         dword |= 0x00 << 16;  /* 100 kHz */
 207 //      dword |= 0x40 << 16;  /* 400 kHz */
 208         dword |= 0xf0 << 24;
 209         saa_writel(SAA7134_I2C_ATTR_STATUS >> 2, dword);
 210         i2c_dbg(2, "i2c data => 0x%x\n", data);
 211
 212         if (!i2c_is_busy_wait(dev))
 213                 return -EIO;
 214         status = i2c_get_status(dev);
 215         if (i2c_is_error(status))
 216                 return -EIO;
 217         return 0;
 218 }
 219
 220 static inline int i2c_recv_byte(struct saa7134_dev *dev)
 221 {
 222         enum i2c_status status;
 223         unsigned char data;
 224
 225         i2c_set_attr(dev,CONTINUE);
 226         if (!i2c_is_busy_wait(dev))
 227                 return -EIO;
 228         status = i2c_get_status(dev);
 229         if (i2c_is_error(status))
 230                 return -EIO;
 231         data = saa_readb(SAA7134_I2C_DATA);
 232         i2c_dbg(2, "i2c data <= 0x%x\n", data);
 233         return data;
 234 }
 235
 236 static int saa7134_i2c_xfer(struct i2c_adapter *i2c_adap,
 237                             struct i2c_msg *msgs, int num)
 238 {
 239         struct saa7134_dev *dev = i2c_adap->algo_data;
 240         enum i2c_status status;
 241         unsigned char data;
 242         int addr,rc,i,byte;
 243
 244         status = i2c_get_status(dev);
 245         if (!i2c_is_idle(status))
 246                 if (!i2c_reset(dev))
 247                         return -EIO;
 248
 249         i2c_dbg(2, "start xfer\n");
 250         i2c_dbg(1, "i2c xfer:");
 251         for (i = 0; i < num; i++) {
 252                 if (!(msgs[i].flags & I2C_M_NOSTART) || 0 == i) {
 253                         /* send address */
 254                         i2c_dbg(2, "send address\n");
 255                         addr  = msgs[i].addr << 1;
 256                         if (msgs[i].flags & I2C_M_RD)
 257                                 addr |= 1;
 258                         if (i > 0 && msgs[i].flags &
 259                             I2C_M_RD && msgs[i].addr != 0x40 &&
 260                             msgs[i].addr != 0x41 &&
 261                             msgs[i].addr != 0x19) {
 262                                 /* workaround for a saa7134 i2c bug
 263                                  * needed to talk to the mt352 demux
 264                                  * thanks to pinnacle for the hint */
 265                                 int quirk = 0xfe;
 266                                 i2c_cont(1, " [%02x quirk]", quirk);
 267                                 i2c_send_byte(dev,START,quirk);
 268                                 i2c_recv_byte(dev);
 269                         }
 270                         i2c_cont(1, " < %02x", addr);
 271                         rc = i2c_send_byte(dev,START,addr);
 272                         if (rc < 0)
 273                                  goto err;
 274                 }
 275                 if (msgs[i].flags & I2C_M_RD) {
 276                         /* read bytes */
 277                         i2c_dbg(2, "read bytes\n");
 278                         for (byte = 0; byte < msgs[i].len; byte++) {
 279                                 i2c_cont(1, " =");
 280                                 rc = i2c_recv_byte(dev);
 281                                 if (rc < 0)
 282                                         goto err;
 283                                 i2c_cont(1, "%02x", rc);
 284                                 msgs[i].buf[byte] = rc;
 285                         }
 286                         /* discard mysterious extra byte when reading
 287                            from Samsung S5H1411.  i2c bus gets error
 288                            if we do not. */
 289                         if (0x19 == msgs[i].addr) {
 290                                 i2c_cont(1, " ?");
 291                                 rc = i2c_recv_byte(dev);
 292                                 if (rc < 0)
 293                                         goto err;
 294                                 i2c_cont(1, "%02x", rc);
 295                         }
 296                 } else {
 297                         /* write bytes */
 298                         i2c_dbg(2, "write bytes\n");
 299                         for (byte = 0; byte < msgs[i].len; byte++) {
 300                                 data = msgs[i].buf[byte];
 301                                 i2c_cont(1, " %02x", data);
 302                                 rc = i2c_send_byte(dev,CONTINUE,data);
 303                                 if (rc < 0)
 304                                         goto err;
 305                         }
 306                 }
 307         }
 308         i2c_dbg(2, "xfer done\n");
 309         i2c_cont(1, " >");
 310         i2c_set_attr(dev,STOP);
 311         rc = -EIO;
 312         if (!i2c_is_busy_wait(dev))
 313                 goto err;
 314         status = i2c_get_status(dev);
 315         if (i2c_is_error(status))
 316                 goto err;
 317         /* ensure that the bus is idle for at least one bit slot */
 318         msleep(1);
 319
 320         i2c_cont(1, "\n");
 321         return num;
 322  err:
 323         if (1 == i2c_debug) {
 324                 status = i2c_get_status(dev);
 325                 i2c_cont(1, " ERROR: %s\n", str_i2c_status[status]);
 326         }
 327         return rc;
 328 }
 329
 330 /* ----------------------------------------------------------- */
 331
 332 static u32 functionality(struct i2c_adapter *adap)
 333 {
 334         return I2C_FUNC_SMBUS_EMUL;
 335 }
 336
 337 static const struct i2c_algorithm saa7134_algo = {
 338         .master_xfer   = saa7134_i2c_xfer,
 339         .functionality = functionality,
 340 };
 341
 342 static const struct i2c_adapter saa7134_adap_template = {
 343         .owner         = THIS_MODULE,
 344         .name          = "saa7134",
 345         .algo          = &saa7134_algo,
 346 };
 347
 348 static const struct i2c_client saa7134_client_template = {
 349         .name   = "saa7134 internal",
 350 };
 351
 352 /* ----------------------------------------------------------- */
 353
 354 /* On Medion 7134 reading EEPROM needs DVB-T demod i2c gate open */
 355 static void saa7134_i2c_eeprom_md7134_gate(struct saa7134_dev *dev)
 356 {
 357         u8 subaddr = 0x7, dmdregval;
 358         u8 data[2];
 359         int ret;
 360         struct i2c_msg i2cgatemsg_r[] = { {.addr = 0x08, .flags = 0,
 361                                            .buf = &subaddr, .len = 1},
 362                                           {.addr = 0x08,
 363                                            .flags = I2C_M_RD,
 364                                            .buf = &dmdregval, .len = 1}
 365                                         };
 366         struct i2c_msg i2cgatemsg_w[] = { {.addr = 0x08, .flags = 0,
 367                                            .buf = data, .len = 2} };
 368
 369         ret = i2c_transfer(&dev->i2c_adap, i2cgatemsg_r, 2);
 370         if ((ret == 2) && (dmdregval & 0x2)) {
 371                 pr_debug("%s: DVB-T demod i2c gate was left closed\n",
 372                          dev->name);
 373
 374                 data[0] = subaddr;
 375                 data[1] = (dmdregval & ~0x2);
 376                 if (i2c_transfer(&dev->i2c_adap, i2cgatemsg_w, 1) != 1)
 377                         pr_err("%s: EEPROM i2c gate open failure\n",
 378                           dev->name);
 379         }
 380 }
 381
 382 static int
 383 saa7134_i2c_eeprom(struct saa7134_dev *dev, unsigned char *eedata, int len)
 384 {
 385         unsigned char buf;
 386         int i,err;
 387
 388         if (dev->board == SAA7134_BOARD_MD7134)
 389                 saa7134_i2c_eeprom_md7134_gate(dev);
 390
 391         dev->i2c_client.addr = 0xa0 >> 1;
 392         buf = 0;
 393         if (1 != (err = i2c_master_send(&dev->i2c_client,&buf,1))) {
 394                 pr_info("%s: Huh, no eeprom present (err=%d)?\n",
 395                        dev->name,err);
 396                 return -1;
 397         }
 398         if (len != (err = i2c_master_recv(&dev->i2c_client,eedata,len))) {
 399                 pr_warn("%s: i2c eeprom read error (err=%d)\n",
 400                        dev->name,err);
 401                 return -1;
 402         }
 403
 404         for (i = 0; i < len; i += 16) {
 405                 int size = (len - i) > 16 ? 16 : len - i;
 406
 407                 pr_info("i2c eeprom %02x: %*ph\n", i, size, &eedata[i]);
 408         }
 409
 410         return 0;
 411 }
 412
 413 static char *i2c_devs[128] = {
 414         [ 0x20      ] = "mpeg encoder (saa6752hs)",
 415         [ 0xa0 >> 1 ] = "eeprom",
 416         [ 0xc0 >> 1 ] = "tuner (analog)",
 417         [ 0x86 >> 1 ] = "tda9887",
 418         [ 0x5a >> 1 ] = "remote control",
 419 };
 420
 421 static void do_i2c_scan(struct i2c_client *c)
 422 {
 423         unsigned char buf;
 424         int i,rc;
 425
 426         for (i = 0; i < ARRAY_SIZE(i2c_devs); i++) {
 427                 c->addr = i;
 428                 rc = i2c_master_recv(c,&buf,0);
 429                 if (rc < 0)
 430                         continue;
 431                 pr_info("i2c scan: found device @ 0x%x  [%s]\n",
 432                          i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
 433         }
 434 }
 435
 436 int saa7134_i2c_register(struct saa7134_dev *dev)
 437 {
 438         dev->i2c_adap = saa7134_adap_template;
 439         dev->i2c_adap.dev.parent = &dev->pci->dev;
 440         strcpy(dev->i2c_adap.name,dev->name);
 441         dev->i2c_adap.algo_data = dev;
 442         i2c_set_adapdata(&dev->i2c_adap, &dev->v4l2_dev);
 443         i2c_add_adapter(&dev->i2c_adap);
 444
 445         dev->i2c_client = saa7134_client_template;
 446         dev->i2c_client.adapter = &dev->i2c_adap;
 447
 448         saa7134_i2c_eeprom(dev,dev->eedata,sizeof(dev->eedata));
 449         if (i2c_scan)
 450                 do_i2c_scan(&dev->i2c_client);
 451
 452         /* Instantiate the IR receiver device, if present */
 453         saa7134_probe_i2c_ir(dev);
 454         return 0;
 455 }
 456
 457 int saa7134_i2c_unregister(struct saa7134_dev *dev)
 458 {
 459         i2c_del_adapter(&dev->i2c_adap);
 460         return 0;
 461 }