linux/drivers/media/pci/saa7134/saa7134-i2c.c
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   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
  32static unsigned int i2c_debug;
  33module_param(i2c_debug, int, 0644);
  34MODULE_PARM_DESC(i2c_debug,"enable debug messages [i2c]");
  35
  36static unsigned int i2c_scan;
  37module_param(i2c_scan, int, 0444);
  38MODULE_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
  55static 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
  61enum 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
  80static char *str_i2c_attr[] = {
  81        "NOP", "STOP", "CONTINUE", "START"
  82};
  83
  84enum 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
  91static 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
 100static 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
 107static 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
 113static 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
 128static 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
 139static 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
 151static 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
 167static 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
 194static 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
 220static 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
 236static 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
 332static u32 functionality(struct i2c_adapter *adap)
 333{
 334        return I2C_FUNC_SMBUS_EMUL;
 335}
 336
 337static const struct i2c_algorithm saa7134_algo = {
 338        .master_xfer   = saa7134_i2c_xfer,
 339        .functionality = functionality,
 340};
 341
 342static const struct i2c_adapter saa7134_adap_template = {
 343        .owner         = THIS_MODULE,
 344        .name          = "saa7134",
 345        .algo          = &saa7134_algo,
 346};
 347
 348static 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 */
 355static 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
 382static int
 383saa7134_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
 413static 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
 421static 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
 436int 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
 457int saa7134_i2c_unregister(struct saa7134_dev *dev)
 458{
 459        i2c_del_adapter(&dev->i2c_adap);
 460        return 0;
 461}
 462