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

DEFINITIONS

1. i2c_get_status
2. i2c_set_status
3. i2c_set_attr
4. i2c_is_error
5. i2c_is_idle
6. i2c_is_busy
7. i2c_is_busy_wait
8. i2c_reset
9. i2c_send_byte
10. i2c_recv_byte
11. saa7134_i2c_xfer
12. functionality
13. saa7134_i2c_eeprom_md7134_gate
14. saa7134_i2c_eeprom
15. do_i2c_scan
16. saa7134_i2c_register
17. saa7134_i2c_unregister

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *
   4  * device driver for philips saa7134 based TV cards
   5  * i2c interface support
   6  *
   7  * (c) 2001,02 Gerd Knorr <kraxel@bytesex.org> [SuSE Labs]
   8  */
   9 
  10 #include "saa7134.h"
  11 #include "saa7134-reg.h"
  12 
  13 #include <linux/init.h>
  14 #include <linux/list.h>
  15 #include <linux/module.h>
  16 #include <linux/kernel.h>
  17 #include <linux/delay.h>
  18 
  19 #include <media/v4l2-common.h>
  20 
  21 /* ----------------------------------------------------------- */
  22 
  23 static unsigned int i2c_debug;
  24 module_param(i2c_debug, int, 0644);
  25 MODULE_PARM_DESC(i2c_debug,"enable debug messages [i2c]");
  26 
  27 static unsigned int i2c_scan;
  28 module_param(i2c_scan, int, 0444);
  29 MODULE_PARM_DESC(i2c_scan,"scan i2c bus at insmod time");
  30 
  31 #define i2c_dbg(level, fmt, arg...) do { \
  32         if (i2c_debug == level) \
  33                 printk(KERN_DEBUG pr_fmt("i2c: " fmt), ## arg); \
  34         } while (0)
  35 
  36 #define i2c_cont(level, fmt, arg...) do { \
  37         if (i2c_debug == level) \
  38                 pr_cont(fmt, ## arg); \
  39         } while (0)
  40 
  41 #define I2C_WAIT_DELAY  32
  42 #define I2C_WAIT_RETRY  16
  43 
  44 /* ----------------------------------------------------------- */
  45 
  46 static char *str_i2c_status[] = {
  47         "IDLE", "DONE_STOP", "BUSY", "TO_SCL", "TO_ARB", "DONE_WRITE",
  48         "DONE_READ", "DONE_WRITE_TO", "DONE_READ_TO", "NO_DEVICE",
  49         "NO_ACKN", "BUS_ERR", "ARB_LOST", "SEQ_ERR", "ST_ERR", "SW_ERR"
  50 };
  51 
  52 enum i2c_status {
  53         IDLE          = 0,  // no I2C command pending
  54         DONE_STOP     = 1,  // I2C command done and STOP executed
  55         BUSY          = 2,  // executing I2C command
  56         TO_SCL        = 3,  // executing I2C command, time out on clock stretching
  57         TO_ARB        = 4,  // time out on arbitration trial, still trying
  58         DONE_WRITE    = 5,  // I2C command done and awaiting next write command
  59         DONE_READ     = 6,  // I2C command done and awaiting next read command
  60         DONE_WRITE_TO = 7,  // see 5, and time out on status echo
  61         DONE_READ_TO  = 8,  // see 6, and time out on status echo
  62         NO_DEVICE     = 9,  // no acknowledge on device slave address
  63         NO_ACKN       = 10, // no acknowledge after data byte transfer
  64         BUS_ERR       = 11, // bus error
  65         ARB_LOST      = 12, // arbitration lost during transfer
  66         SEQ_ERR       = 13, // erroneous programming sequence
  67         ST_ERR        = 14, // wrong status echoing
  68         SW_ERR        = 15  // software error
  69 };
  70 
  71 static char *str_i2c_attr[] = {
  72         "NOP", "STOP", "CONTINUE", "START"
  73 };
  74 
  75 enum i2c_attr {
  76         NOP           = 0,  // no operation on I2C bus
  77         STOP          = 1,  // stop condition, no associated byte transfer
  78         CONTINUE      = 2,  // continue with byte transfer
  79         START         = 3   // start condition with byte transfer
  80 };
  81 
  82 static inline enum i2c_status i2c_get_status(struct saa7134_dev *dev)
  83 {
  84         enum i2c_status status;
  85 
  86         status = saa_readb(SAA7134_I2C_ATTR_STATUS) & 0x0f;
  87         i2c_dbg(2, "i2c stat <= %s\n", str_i2c_status[status]);
  88         return status;
  89 }
  90 
  91 static inline void i2c_set_status(struct saa7134_dev *dev,
  92                                   enum i2c_status status)
  93 {
  94         i2c_dbg(2, "i2c stat => %s\n", str_i2c_status[status]);
  95         saa_andorb(SAA7134_I2C_ATTR_STATUS,0x0f,status);
  96 }
  97 
  98 static inline void i2c_set_attr(struct saa7134_dev *dev, enum i2c_attr attr)
  99 {
 100         i2c_dbg(2, "i2c attr => %s\n", str_i2c_attr[attr]);
 101         saa_andorb(SAA7134_I2C_ATTR_STATUS,0xc0,attr << 6);
 102 }
 103 
 104 static inline int i2c_is_error(enum i2c_status status)
 105 {
 106         switch (status) {
 107         case NO_DEVICE:
 108         case NO_ACKN:
 109         case BUS_ERR:
 110         case ARB_LOST:
 111         case SEQ_ERR:
 112         case ST_ERR:
 113                 return true;
 114         default:
 115                 return false;
 116         }
 117 }
 118 
 119 static inline int i2c_is_idle(enum i2c_status status)
 120 {
 121         switch (status) {
 122         case IDLE:
 123         case DONE_STOP:
 124                 return true;
 125         default:
 126                 return false;
 127         }
 128 }
 129 
 130 static inline int i2c_is_busy(enum i2c_status status)
 131 {
 132         switch (status) {
 133         case BUSY:
 134         case TO_SCL:
 135         case TO_ARB:
 136                 return true;
 137         default:
 138                 return false;
 139         }
 140 }
 141 
 142 static int i2c_is_busy_wait(struct saa7134_dev *dev)
 143 {
 144         enum i2c_status status;
 145         int count;
 146 
 147         for (count = 0; count < I2C_WAIT_RETRY; count++) {
 148                 status = i2c_get_status(dev);
 149                 if (!i2c_is_busy(status))
 150                         break;
 151                 saa_wait(I2C_WAIT_DELAY);
 152         }
 153         if (I2C_WAIT_RETRY == count)
 154                 return false;
 155         return true;
 156 }
 157 
 158 static int i2c_reset(struct saa7134_dev *dev)
 159 {
 160         enum i2c_status status;
 161         int count;
 162 
 163         i2c_dbg(2, "i2c reset\n");
 164         status = i2c_get_status(dev);
 165         if (!i2c_is_error(status))
 166                 return true;
 167         i2c_set_status(dev,status);
 168 
 169         for (count = 0; count < I2C_WAIT_RETRY; count++) {
 170                 status = i2c_get_status(dev);
 171                 if (!i2c_is_error(status))
 172                         break;
 173                 udelay(I2C_WAIT_DELAY);
 174         }
 175         if (I2C_WAIT_RETRY == count)
 176                 return false;
 177 
 178         if (!i2c_is_idle(status))
 179                 return false;
 180 
 181         i2c_set_attr(dev,NOP);
 182         return true;
 183 }
 184 
 185 static inline int i2c_send_byte(struct saa7134_dev *dev,
 186                                 enum i2c_attr attr,
 187                                 unsigned char data)
 188 {
 189         enum i2c_status status;
 190         __u32 dword;
 191 
 192         /* have to write both attr + data in one 32bit word */
 193         dword  = saa_readl(SAA7134_I2C_ATTR_STATUS >> 2);
 194         dword &= 0x0f;
 195         dword |= (attr << 6);
 196         dword |= ((__u32)data << 8);
 197         dword |= 0x00 << 16;  /* 100 kHz */
 198 //      dword |= 0x40 << 16;  /* 400 kHz */
 199         dword |= 0xf0 << 24;
 200         saa_writel(SAA7134_I2C_ATTR_STATUS >> 2, dword);
 201         i2c_dbg(2, "i2c data => 0x%x\n", data);
 202 
 203         if (!i2c_is_busy_wait(dev))
 204                 return -EIO;
 205         status = i2c_get_status(dev);
 206         if (i2c_is_error(status))
 207                 return -EIO;
 208         return 0;
 209 }
 210 
 211 static inline int i2c_recv_byte(struct saa7134_dev *dev)
 212 {
 213         enum i2c_status status;
 214         unsigned char data;
 215 
 216         i2c_set_attr(dev,CONTINUE);
 217         if (!i2c_is_busy_wait(dev))
 218                 return -EIO;
 219         status = i2c_get_status(dev);
 220         if (i2c_is_error(status))
 221                 return -EIO;
 222         data = saa_readb(SAA7134_I2C_DATA);
 223         i2c_dbg(2, "i2c data <= 0x%x\n", data);
 224         return data;
 225 }
 226 
 227 static int saa7134_i2c_xfer(struct i2c_adapter *i2c_adap,
 228                             struct i2c_msg *msgs, int num)
 229 {
 230         struct saa7134_dev *dev = i2c_adap->algo_data;
 231         enum i2c_status status;
 232         unsigned char data;
 233         int addr,rc,i,byte;
 234 
 235         status = i2c_get_status(dev);
 236         if (!i2c_is_idle(status))
 237                 if (!i2c_reset(dev))
 238                         return -EIO;
 239 
 240         i2c_dbg(2, "start xfer\n");
 241         i2c_dbg(1, "i2c xfer:");
 242         for (i = 0; i < num; i++) {
 243                 if (!(msgs[i].flags & I2C_M_NOSTART) || 0 == i) {
 244                         /* send address */
 245                         i2c_dbg(2, "send address\n");
 246                         addr  = msgs[i].addr << 1;
 247                         if (msgs[i].flags & I2C_M_RD)
 248                                 addr |= 1;
 249                         if (i > 0 && msgs[i].flags &
 250                             I2C_M_RD && msgs[i].addr != 0x40 &&
 251                             msgs[i].addr != 0x41 &&
 252                             msgs[i].addr != 0x19) {
 253                                 /* workaround for a saa7134 i2c bug
 254                                  * needed to talk to the mt352 demux
 255                                  * thanks to pinnacle for the hint */
 256                                 int quirk = 0xfe;
 257                                 i2c_cont(1, " [%02x quirk]", quirk);
 258                                 i2c_send_byte(dev,START,quirk);
 259                                 i2c_recv_byte(dev);
 260                         }
 261                         i2c_cont(1, " < %02x", addr);
 262                         rc = i2c_send_byte(dev,START,addr);
 263                         if (rc < 0)
 264                                  goto err;
 265                 }
 266                 if (msgs[i].flags & I2C_M_RD) {
 267                         /* read bytes */
 268                         i2c_dbg(2, "read bytes\n");
 269                         for (byte = 0; byte < msgs[i].len; byte++) {
 270                                 i2c_cont(1, " =");
 271                                 rc = i2c_recv_byte(dev);
 272                                 if (rc < 0)
 273                                         goto err;
 274                                 i2c_cont(1, "%02x", rc);
 275                                 msgs[i].buf[byte] = rc;
 276                         }
 277                         /* discard mysterious extra byte when reading
 278                            from Samsung S5H1411.  i2c bus gets error
 279                            if we do not. */
 280                         if (0x19 == msgs[i].addr) {
 281                                 i2c_cont(1, " ?");
 282                                 rc = i2c_recv_byte(dev);
 283                                 if (rc < 0)
 284                                         goto err;
 285                                 i2c_cont(1, "%02x", rc);
 286                         }
 287                 } else {
 288                         /* write bytes */
 289                         i2c_dbg(2, "write bytes\n");
 290                         for (byte = 0; byte < msgs[i].len; byte++) {
 291                                 data = msgs[i].buf[byte];
 292                                 i2c_cont(1, " %02x", data);
 293                                 rc = i2c_send_byte(dev,CONTINUE,data);
 294                                 if (rc < 0)
 295                                         goto err;
 296                         }
 297                 }
 298         }
 299         i2c_dbg(2, "xfer done\n");
 300         i2c_cont(1, " >");
 301         i2c_set_attr(dev,STOP);
 302         rc = -EIO;
 303         if (!i2c_is_busy_wait(dev))
 304                 goto err;
 305         status = i2c_get_status(dev);
 306         if (i2c_is_error(status))
 307                 goto err;
 308         /* ensure that the bus is idle for at least one bit slot */
 309         msleep(1);
 310 
 311         i2c_cont(1, "\n");
 312         return num;
 313  err:
 314         if (1 == i2c_debug) {
 315                 status = i2c_get_status(dev);
 316                 i2c_cont(1, " ERROR: %s\n", str_i2c_status[status]);
 317         }
 318         return rc;
 319 }
 320 
 321 /* ----------------------------------------------------------- */
 322 
 323 static u32 functionality(struct i2c_adapter *adap)
 324 {
 325         return I2C_FUNC_SMBUS_EMUL;
 326 }
 327 
 328 static const struct i2c_algorithm saa7134_algo = {
 329         .master_xfer   = saa7134_i2c_xfer,
 330         .functionality = functionality,
 331 };
 332 
 333 static const struct i2c_adapter saa7134_adap_template = {
 334         .owner         = THIS_MODULE,
 335         .name          = "saa7134",
 336         .algo          = &saa7134_algo,
 337 };
 338 
 339 static const struct i2c_client saa7134_client_template = {
 340         .name   = "saa7134 internal",
 341 };
 342 
 343 /* ----------------------------------------------------------- */
 344 
 345 /*
 346  * On Medion 7134 reading the SAA7134 chip config EEPROM needs DVB-T
 347  * demod i2c gate closed due to an address clash between this EEPROM
 348  * and the demod one.
 349  */
 350 static void saa7134_i2c_eeprom_md7134_gate(struct saa7134_dev *dev)
 351 {
 352         u8 subaddr = 0x7, dmdregval;
 353         u8 data[2];
 354         int ret;
 355         struct i2c_msg i2cgatemsg_r[] = { {.addr = 0x08, .flags = 0,
 356                                            .buf = &subaddr, .len = 1},
 357                                           {.addr = 0x08,
 358                                            .flags = I2C_M_RD,
 359                                            .buf = &dmdregval, .len = 1}
 360                                         };
 361         struct i2c_msg i2cgatemsg_w[] = { {.addr = 0x08, .flags = 0,
 362                                            .buf = data, .len = 2} };
 363 
 364         ret = i2c_transfer(&dev->i2c_adap, i2cgatemsg_r, 2);
 365         if ((ret == 2) && (dmdregval & 0x2)) {
 366                 pr_debug("%s: DVB-T demod i2c gate was left open\n",
 367                          dev->name);
 368 
 369                 data[0] = subaddr;
 370                 data[1] = (dmdregval & ~0x2);
 371                 if (i2c_transfer(&dev->i2c_adap, i2cgatemsg_w, 1) != 1)
 372                         pr_err("%s: EEPROM i2c gate close failure\n",
 373                                dev->name);
 374         }
 375 }
 376 
 377 static int
 378 saa7134_i2c_eeprom(struct saa7134_dev *dev, unsigned char *eedata, int len)
 379 {
 380         unsigned char buf;
 381         int i,err;
 382 
 383         if (dev->board == SAA7134_BOARD_MD7134)
 384                 saa7134_i2c_eeprom_md7134_gate(dev);
 385 
 386         dev->i2c_client.addr = 0xa0 >> 1;
 387         buf = 0;
 388         if (1 != (err = i2c_master_send(&dev->i2c_client,&buf,1))) {
 389                 pr_info("%s: Huh, no eeprom present (err=%d)?\n",
 390                        dev->name,err);
 391                 return -1;
 392         }
 393         if (len != (err = i2c_master_recv(&dev->i2c_client,eedata,len))) {
 394                 pr_warn("%s: i2c eeprom read error (err=%d)\n",
 395                        dev->name,err);
 396                 return -1;
 397         }
 398 
 399         for (i = 0; i < len; i += 16) {
 400                 int size = (len - i) > 16 ? 16 : len - i;
 401 
 402                 pr_info("i2c eeprom %02x: %*ph\n", i, size, &eedata[i]);
 403         }
 404 
 405         return 0;
 406 }
 407 
 408 static char *i2c_devs[128] = {
 409         [ 0x20      ] = "mpeg encoder (saa6752hs)",
 410         [ 0xa0 >> 1 ] = "eeprom",
 411         [ 0xc0 >> 1 ] = "tuner (analog)",
 412         [ 0x86 >> 1 ] = "tda9887",
 413         [ 0x5a >> 1 ] = "remote control",
 414 };
 415 
 416 static void do_i2c_scan(struct i2c_client *c)
 417 {
 418         unsigned char buf;
 419         int i,rc;
 420 
 421         for (i = 0; i < ARRAY_SIZE(i2c_devs); i++) {
 422                 c->addr = i;
 423                 rc = i2c_master_recv(c,&buf,0);
 424                 if (rc < 0)
 425                         continue;
 426                 pr_info("i2c scan: found device @ 0x%x  [%s]\n",
 427                          i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
 428         }
 429 }
 430 
 431 int saa7134_i2c_register(struct saa7134_dev *dev)
 432 {
 433         dev->i2c_adap = saa7134_adap_template;
 434         dev->i2c_adap.dev.parent = &dev->pci->dev;
 435         strscpy(dev->i2c_adap.name, dev->name, sizeof(dev->i2c_adap.name));
 436         dev->i2c_adap.algo_data = dev;
 437         i2c_set_adapdata(&dev->i2c_adap, &dev->v4l2_dev);
 438         i2c_add_adapter(&dev->i2c_adap);
 439 
 440         dev->i2c_client = saa7134_client_template;
 441         dev->i2c_client.adapter = &dev->i2c_adap;
 442 
 443         saa7134_i2c_eeprom(dev,dev->eedata,sizeof(dev->eedata));
 444         if (i2c_scan)
 445                 do_i2c_scan(&dev->i2c_client);
 446 
 447         /* Instantiate the IR receiver device, if present */
 448         saa7134_probe_i2c_ir(dev);
 449         return 0;
 450 }
 451 
 452 int saa7134_i2c_unregister(struct saa7134_dev *dev)
 453 {
 454         i2c_del_adapter(&dev->i2c_adap);
 455         return 0;
 456 }