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  *  You should have received a copy of the GNU General Public License
  19  *  along with this program; if not, write to the Free Software
  20  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21  */
  22
  23 #include "saa7134.h"
  24 #include "saa7134-reg.h"
  25
  26 #include <linux/init.h>
  27 #include <linux/list.h>
  28 #include <linux/module.h>
  29 #include <linux/kernel.h>
  30 #include <linux/delay.h>
  31
  32 #include <media/v4l2-common.h>
  33
  34 /* ----------------------------------------------------------- */
  35
  36 static unsigned int i2c_debug;
  37 module_param(i2c_debug, int, 0644);
  38 MODULE_PARM_DESC(i2c_debug,"enable debug messages [i2c]");
  39
  40 static unsigned int i2c_scan;
  41 module_param(i2c_scan, int, 0444);
  42 MODULE_PARM_DESC(i2c_scan,"scan i2c bus at insmod time");
  43
  44 #define i2c_dbg(level, fmt, arg...) do { \
  45         if (i2c_debug == level) \
  46                 printk(KERN_DEBUG pr_fmt("i2c: " fmt), ## arg); \
  47         } while (0)
  48
  49 #define i2c_cont(level, fmt, arg...) do { \
  50         if (i2c_debug == level) \
  51                 pr_cont(fmt, ## arg); \
  52         } while (0)
  53
  54 #define I2C_WAIT_DELAY  32
  55 #define I2C_WAIT_RETRY  16
  56
  57 /* ----------------------------------------------------------- */
  58
  59 static char *str_i2c_status[] = {
  60         "IDLE", "DONE_STOP", "BUSY", "TO_SCL", "TO_ARB", "DONE_WRITE",
  61         "DONE_READ", "DONE_WRITE_TO", "DONE_READ_TO", "NO_DEVICE",
  62         "NO_ACKN", "BUS_ERR", "ARB_LOST", "SEQ_ERR", "ST_ERR", "SW_ERR"
  63 };
  64
  65 enum i2c_status {
  66         IDLE          = 0,  // no I2C command pending
  67         DONE_STOP     = 1,  // I2C command done and STOP executed
  68         BUSY          = 2,  // executing I2C command
  69         TO_SCL        = 3,  // executing I2C command, time out on clock stretching
  70         TO_ARB        = 4,  // time out on arbitration trial, still trying
  71         DONE_WRITE    = 5,  // I2C command done and awaiting next write command
  72         DONE_READ     = 6,  // I2C command done and awaiting next read command
  73         DONE_WRITE_TO = 7,  // see 5, and time out on status echo
  74         DONE_READ_TO  = 8,  // see 6, and time out on status echo
  75         NO_DEVICE     = 9,  // no acknowledge on device slave address
  76         NO_ACKN       = 10, // no acknowledge after data byte transfer
  77         BUS_ERR       = 11, // bus error
  78         ARB_LOST      = 12, // arbitration lost during transfer
  79         SEQ_ERR       = 13, // erroneous programming sequence
  80         ST_ERR        = 14, // wrong status echoing
  81         SW_ERR        = 15  // software error
  82 };
  83
  84 static char *str_i2c_attr[] = {
  85         "NOP", "STOP", "CONTINUE", "START"
  86 };
  87
  88 enum i2c_attr {
  89         NOP           = 0,  // no operation on I2C bus
  90         STOP          = 1,  // stop condition, no associated byte transfer
  91         CONTINUE      = 2,  // continue with byte transfer
  92         START         = 3   // start condition with byte transfer
  93 };
  94
  95 static inline enum i2c_status i2c_get_status(struct saa7134_dev *dev)
  96 {
  97         enum i2c_status status;
  98
  99         status = saa_readb(SAA7134_I2C_ATTR_STATUS) & 0x0f;
 100         i2c_dbg(2, "i2c stat <= %s\n", str_i2c_status[status]);
 101         return status;
 102 }
 103
 104 static inline void i2c_set_status(struct saa7134_dev *dev,
 105                                   enum i2c_status status)
 106 {
 107         i2c_dbg(2, "i2c stat => %s\n", str_i2c_status[status]);
 108         saa_andorb(SAA7134_I2C_ATTR_STATUS,0x0f,status);
 109 }
 110
 111 static inline void i2c_set_attr(struct saa7134_dev *dev, enum i2c_attr attr)
 112 {
 113         i2c_dbg(2, "i2c attr => %s\n", str_i2c_attr[attr]);
 114         saa_andorb(SAA7134_I2C_ATTR_STATUS,0xc0,attr << 6);
 115 }
 116
 117 static inline int i2c_is_error(enum i2c_status status)
 118 {
 119         switch (status) {
 120         case NO_DEVICE:
 121         case NO_ACKN:
 122         case BUS_ERR:
 123         case ARB_LOST:
 124         case SEQ_ERR:
 125         case ST_ERR:
 126                 return true;
 127         default:
 128                 return false;
 129         }
 130 }
 131
 132 static inline int i2c_is_idle(enum i2c_status status)
 133 {
 134         switch (status) {
 135         case IDLE:
 136         case DONE_STOP:
 137                 return true;
 138         default:
 139                 return false;
 140         }
 141 }
 142
 143 static inline int i2c_is_busy(enum i2c_status status)
 144 {
 145         switch (status) {
 146         case BUSY:
 147         case TO_SCL:
 148         case TO_ARB:
 149                 return true;
 150         default:
 151                 return false;
 152         }
 153 }
 154
 155 static int i2c_is_busy_wait(struct saa7134_dev *dev)
 156 {
 157         enum i2c_status status;
 158         int count;
 159
 160         for (count = 0; count < I2C_WAIT_RETRY; count++) {
 161                 status = i2c_get_status(dev);
 162                 if (!i2c_is_busy(status))
 163                         break;
 164                 saa_wait(I2C_WAIT_DELAY);
 165         }
 166         if (I2C_WAIT_RETRY == count)
 167                 return false;
 168         return true;
 169 }
 170
 171 static int i2c_reset(struct saa7134_dev *dev)
 172 {
 173         enum i2c_status status;
 174         int count;
 175
 176         i2c_dbg(2, "i2c reset\n");
 177         status = i2c_get_status(dev);
 178         if (!i2c_is_error(status))
 179                 return true;
 180         i2c_set_status(dev,status);
 181
 182         for (count = 0; count < I2C_WAIT_RETRY; count++) {
 183                 status = i2c_get_status(dev);
 184                 if (!i2c_is_error(status))
 185                         break;
 186                 udelay(I2C_WAIT_DELAY);
 187         }
 188         if (I2C_WAIT_RETRY == count)
 189                 return false;
 190
 191         if (!i2c_is_idle(status))
 192                 return false;
 193
 194         i2c_set_attr(dev,NOP);
 195         return true;
 196 }
 197
 198 static inline int i2c_send_byte(struct saa7134_dev *dev,
 199                                 enum i2c_attr attr,
 200                                 unsigned char data)
 201 {
 202         enum i2c_status status;
 203         __u32 dword;
 204
 205         /* have to write both attr + data in one 32bit word */
 206         dword  = saa_readl(SAA7134_I2C_ATTR_STATUS >> 2);
 207         dword &= 0x0f;
 208         dword |= (attr << 6);
 209         dword |= ((__u32)data << 8);
 210         dword |= 0x00 << 16;  /* 100 kHz */
 211 //      dword |= 0x40 << 16;  /* 400 kHz */
 212         dword |= 0xf0 << 24;
 213         saa_writel(SAA7134_I2C_ATTR_STATUS >> 2, dword);
 214         i2c_dbg(2, "i2c data => 0x%x\n", data);
 215
 216         if (!i2c_is_busy_wait(dev))
 217                 return -EIO;
 218         status = i2c_get_status(dev);
 219         if (i2c_is_error(status))
 220                 return -EIO;
 221         return 0;
 222 }
 223
 224 static inline int i2c_recv_byte(struct saa7134_dev *dev)
 225 {
 226         enum i2c_status status;
 227         unsigned char data;
 228
 229         i2c_set_attr(dev,CONTINUE);
 230         if (!i2c_is_busy_wait(dev))
 231                 return -EIO;
 232         status = i2c_get_status(dev);
 233         if (i2c_is_error(status))
 234                 return -EIO;
 235         data = saa_readb(SAA7134_I2C_DATA);
 236         i2c_dbg(2, "i2c data <= 0x%x\n", data);
 237         return data;
 238 }
 239
 240 static int saa7134_i2c_xfer(struct i2c_adapter *i2c_adap,
 241                             struct i2c_msg *msgs, int num)
 242 {
 243         struct saa7134_dev *dev = i2c_adap->algo_data;
 244         enum i2c_status status;
 245         unsigned char data;
 246         int addr,rc,i,byte;
 247
 248         status = i2c_get_status(dev);
 249         if (!i2c_is_idle(status))
 250                 if (!i2c_reset(dev))
 251                         return -EIO;
 252
 253         i2c_dbg(2, "start xfer\n");
 254         i2c_dbg(1, "i2c xfer:");
 255         for (i = 0; i < num; i++) {
 256                 if (!(msgs[i].flags & I2C_M_NOSTART) || 0 == i) {
 257                         /* send address */
 258                         i2c_dbg(2, "send address\n");
 259                         addr  = msgs[i].addr << 1;
 260                         if (msgs[i].flags & I2C_M_RD)
 261                                 addr |= 1;
 262                         if (i > 0 && msgs[i].flags &
 263                             I2C_M_RD && msgs[i].addr != 0x40 &&
 264                             msgs[i].addr != 0x41 &&
 265                             msgs[i].addr != 0x19) {
 266                                 /* workaround for a saa7134 i2c bug
 267                                  * needed to talk to the mt352 demux
 268                                  * thanks to pinnacle for the hint */
 269                                 int quirk = 0xfe;
 270                                 i2c_cont(1, " [%02x quirk]", quirk);
 271                                 i2c_send_byte(dev,START,quirk);
 272                                 i2c_recv_byte(dev);
 273                         }
 274                         i2c_cont(1, " < %02x", addr);
 275                         rc = i2c_send_byte(dev,START,addr);
 276                         if (rc < 0)
 277                                  goto err;
 278                 }
 279                 if (msgs[i].flags & I2C_M_RD) {
 280                         /* read bytes */
 281                         i2c_dbg(2, "read bytes\n");
 282                         for (byte = 0; byte < msgs[i].len; byte++) {
 283                                 i2c_cont(1, " =");
 284                                 rc = i2c_recv_byte(dev);
 285                                 if (rc < 0)
 286                                         goto err;
 287                                 i2c_cont(1, "%02x", rc);
 288                                 msgs[i].buf[byte] = rc;
 289                         }
 290                         /* discard mysterious extra byte when reading
 291                            from Samsung S5H1411.  i2c bus gets error
 292                            if we do not. */
 293                         if (0x19 == msgs[i].addr) {
 294                                 i2c_cont(1, " ?");
 295                                 rc = i2c_recv_byte(dev);
 296                                 if (rc < 0)
 297                                         goto err;
 298                                 i2c_cont(1, "%02x", rc);
 299                         }
 300                 } else {
 301                         /* write bytes */
 302                         i2c_dbg(2, "write bytes\n");
 303                         for (byte = 0; byte < msgs[i].len; byte++) {
 304                                 data = msgs[i].buf[byte];
 305                                 i2c_cont(1, " %02x", data);
 306                                 rc = i2c_send_byte(dev,CONTINUE,data);
 307                                 if (rc < 0)
 308                                         goto err;
 309                         }
 310                 }
 311         }
 312         i2c_dbg(2, "xfer done\n");
 313         i2c_cont(1, " >");
 314         i2c_set_attr(dev,STOP);
 315         rc = -EIO;
 316         if (!i2c_is_busy_wait(dev))
 317                 goto err;
 318         status = i2c_get_status(dev);
 319         if (i2c_is_error(status))
 320                 goto err;
 321         /* ensure that the bus is idle for at least one bit slot */
 322         msleep(1);
 323
 324         i2c_cont(1, "\n");
 325         return num;
 326  err:
 327         if (1 == i2c_debug) {
 328                 status = i2c_get_status(dev);
 329                 i2c_cont(1, " ERROR: %s\n", str_i2c_status[status]);
 330         }
 331         return rc;
 332 }
 333
 334 /* ----------------------------------------------------------- */
 335
 336 static u32 functionality(struct i2c_adapter *adap)
 337 {
 338         return I2C_FUNC_SMBUS_EMUL;
 339 }
 340
 341 static struct i2c_algorithm saa7134_algo = {
 342         .master_xfer   = saa7134_i2c_xfer,
 343         .functionality = functionality,
 344 };
 345
 346 static struct i2c_adapter saa7134_adap_template = {
 347         .owner         = THIS_MODULE,
 348         .name          = "saa7134",
 349         .algo          = &saa7134_algo,
 350 };
 351
 352 static struct i2c_client saa7134_client_template = {
 353         .name   = "saa7134 internal",
 354 };
 355
 356 /* ----------------------------------------------------------- */
 357
 358 static int
 359 saa7134_i2c_eeprom(struct saa7134_dev *dev, unsigned char *eedata, int len)
 360 {
 361         unsigned char buf;
 362         int i,err;
 363
 364         dev->i2c_client.addr = 0xa0 >> 1;
 365         buf = 0;
 366         if (1 != (err = i2c_master_send(&dev->i2c_client,&buf,1))) {
 367                 pr_info("%s: Huh, no eeprom present (err=%d)?\n",
 368                        dev->name,err);
 369                 return -1;
 370         }
 371         if (len != (err = i2c_master_recv(&dev->i2c_client,eedata,len))) {
 372                 pr_warn("%s: i2c eeprom read error (err=%d)\n",
 373                        dev->name,err);
 374                 return -1;
 375         }
 376
 377         for (i = 0; i < len; i += 16) {
 378                 int size = (len - i) > 16 ? 16 : len - i;
 379
 380                 pr_info("i2c eeprom %02x: %*ph\n", i, size, &eedata[i]);
 381         }
 382
 383         return 0;
 384 }
 385
 386 static char *i2c_devs[128] = {
 387         [ 0x20      ] = "mpeg encoder (saa6752hs)",
 388         [ 0xa0 >> 1 ] = "eeprom",
 389         [ 0xc0 >> 1 ] = "tuner (analog)",
 390         [ 0x86 >> 1 ] = "tda9887",
 391         [ 0x5a >> 1 ] = "remote control",
 392 };
 393
 394 static void do_i2c_scan(struct i2c_client *c)
 395 {
 396         unsigned char buf;
 397         int i,rc;
 398
 399         for (i = 0; i < ARRAY_SIZE(i2c_devs); i++) {
 400                 c->addr = i;
 401                 rc = i2c_master_recv(c,&buf,0);
 402                 if (rc < 0)
 403                         continue;
 404                 pr_info("i2c scan: found device @ 0x%x  [%s]\n",
 405                          i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
 406         }
 407 }
 408
 409 int saa7134_i2c_register(struct saa7134_dev *dev)
 410 {
 411         dev->i2c_adap = saa7134_adap_template;
 412         dev->i2c_adap.dev.parent = &dev->pci->dev;
 413         strcpy(dev->i2c_adap.name,dev->name);
 414         dev->i2c_adap.algo_data = dev;
 415         i2c_set_adapdata(&dev->i2c_adap, &dev->v4l2_dev);
 416         i2c_add_adapter(&dev->i2c_adap);
 417
 418         dev->i2c_client = saa7134_client_template;
 419         dev->i2c_client.adapter = &dev->i2c_adap;
 420
 421         saa7134_i2c_eeprom(dev,dev->eedata,sizeof(dev->eedata));
 422         if (i2c_scan)
 423                 do_i2c_scan(&dev->i2c_client);
 424
 425         /* Instantiate the IR receiver device, if present */
 426         saa7134_probe_i2c_ir(dev);
 427         return 0;
 428 }
 429
 430 int saa7134_i2c_unregister(struct saa7134_dev *dev)
 431 {
 432         i2c_del_adapter(&dev->i2c_adap);
 433         return 0;
 434 }