drivers/media/video/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 <linux/init.h>
  24 #include <linux/list.h>
  25 #include <linux/module.h>
  26 #include <linux/kernel.h>
  27 #include <linux/slab.h>
  28 #include <linux/delay.h>
  29
  30 #include "saa7134-reg.h"
  31 #include "saa7134.h"
  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 d1printk if (1 == i2c_debug) printk
  45 #define d2printk if (2 == i2c_debug) printk
  46
  47 #define I2C_WAIT_DELAY  32
  48 #define I2C_WAIT_RETRY  16
  49
  50 /* ----------------------------------------------------------- */
  51
  52 static char *str_i2c_status[] = {
  53         "IDLE", "DONE_STOP", "BUSY", "TO_SCL", "TO_ARB", "DONE_WRITE",
  54         "DONE_READ", "DONE_WRITE_TO", "DONE_READ_TO", "NO_DEVICE",
  55         "NO_ACKN", "BUS_ERR", "ARB_LOST", "SEQ_ERR", "ST_ERR", "SW_ERR"
  56 };
  57
  58 enum i2c_status {
  59         IDLE          = 0,  // no I2C command pending
  60         DONE_STOP     = 1,  // I2C command done and STOP executed
  61         BUSY          = 2,  // executing I2C command
  62         TO_SCL        = 3,  // executing I2C command, time out on clock stretching
  63         TO_ARB        = 4,  // time out on arbitration trial, still trying
  64         DONE_WRITE    = 5,  // I2C command done and awaiting next write command
  65         DONE_READ     = 6,  // I2C command done and awaiting next read command
  66         DONE_WRITE_TO = 7,  // see 5, and time out on status echo
  67         DONE_READ_TO  = 8,  // see 6, and time out on status echo
  68         NO_DEVICE     = 9,  // no acknowledge on device slave address
  69         NO_ACKN       = 10, // no acknowledge after data byte transfer
  70         BUS_ERR       = 11, // bus error
  71         ARB_LOST      = 12, // arbitration lost during transfer
  72         SEQ_ERR       = 13, // erroneous programming sequence
  73         ST_ERR        = 14, // wrong status echoing
  74         SW_ERR        = 15  // software error
  75 };
  76
  77 static char *str_i2c_attr[] = {
  78         "NOP", "STOP", "CONTINUE", "START"
  79 };
  80
  81 enum i2c_attr {
  82         NOP           = 0,  // no operation on I2C bus
  83         STOP          = 1,  // stop condition, no associated byte transfer
  84         CONTINUE      = 2,  // continue with byte transfer
  85         START         = 3   // start condition with byte transfer
  86 };
  87
  88 static inline enum i2c_status i2c_get_status(struct saa7134_dev *dev)
  89 {
  90         enum i2c_status status;
  91
  92         status = saa_readb(SAA7134_I2C_ATTR_STATUS) & 0x0f;
  93         d2printk(KERN_DEBUG "%s: i2c stat <= %s\n",dev->name,
  94                  str_i2c_status[status]);
  95         return status;
  96 }
  97
  98 static inline void i2c_set_status(struct saa7134_dev *dev,
  99                                   enum i2c_status status)
 100 {
 101         d2printk(KERN_DEBUG "%s: i2c stat => %s\n",dev->name,
 102                  str_i2c_status[status]);
 103         saa_andorb(SAA7134_I2C_ATTR_STATUS,0x0f,status);
 104 }
 105
 106 static inline void i2c_set_attr(struct saa7134_dev *dev, enum i2c_attr attr)
 107 {
 108         d2printk(KERN_DEBUG "%s: i2c attr => %s\n",dev->name,
 109                  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         d2printk(KERN_DEBUG "%s: i2c reset\n",dev->name);
 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         d2printk(KERN_DEBUG "%s: i2c data => 0x%x\n",dev->name,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         d2printk(KERN_DEBUG "%s: i2c data <= 0x%x\n",dev->name,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         d2printk("start xfer\n");
 250         d1printk(KERN_DEBUG "%s: i2c xfer:",dev->name);
 251         for (i = 0; i < num; i++) {
 252                 if (!(msgs[i].flags & I2C_M_NOSTART) || 0 == i) {
 253                         /* send address */
 254                         d2printk("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 & I2C_M_RD && msgs[i].addr != 0x40) {
 259                                 /* workaround for a saa7134 i2c bug
 260                                  * needed to talk to the mt352 demux
 261                                  * thanks to pinnacle for the hint */
 262                                 int quirk = 0xfd;
 263                                 d1printk(" [%02x quirk]",quirk);
 264                                 i2c_send_byte(dev,START,quirk);
 265                                 i2c_recv_byte(dev);
 266                         }
 267                         d1printk(" < %02x", addr);
 268                         rc = i2c_send_byte(dev,START,addr);
 269                         if (rc < 0)
 270                                  goto err;
 271                 }
 272                 if (msgs[i].flags & I2C_M_RD) {
 273                         /* read bytes */
 274                         d2printk("read bytes\n");
 275                         for (byte = 0; byte < msgs[i].len; byte++) {
 276                                 d1printk(" =");
 277                                 rc = i2c_recv_byte(dev);
 278                                 if (rc < 0)
 279                                         goto err;
 280                                 d1printk("%02x", rc);
 281                                 msgs[i].buf[byte] = rc;
 282                         }
 283                 } else {
 284                         /* write bytes */
 285                         d2printk("write bytes\n");
 286                         for (byte = 0; byte < msgs[i].len; byte++) {
 287                                 data = msgs[i].buf[byte];
 288                                 d1printk(" %02x", data);
 289                                 rc = i2c_send_byte(dev,CONTINUE,data);
 290                                 if (rc < 0)
 291                                         goto err;
 292                         }
 293                 }
 294         }
 295         d2printk("xfer done\n");
 296         d1printk(" >");
 297         i2c_set_attr(dev,STOP);
 298         rc = -EIO;
 299         if (!i2c_is_busy_wait(dev))
 300                 goto err;
 301         status = i2c_get_status(dev);
 302         if (i2c_is_error(status))
 303                 goto err;
 304         /* ensure that the bus is idle for at least one bit slot */
 305         msleep(1);
 306
 307         d1printk("\n");
 308         return num;
 309  err:
 310         if (1 == i2c_debug) {
 311                 status = i2c_get_status(dev);
 312                 printk(" ERROR: %s\n",str_i2c_status[status]);
 313         }
 314         return rc;
 315 }
 316
 317 /* ----------------------------------------------------------- */
 318
 319 static u32 functionality(struct i2c_adapter *adap)
 320 {
 321         return I2C_FUNC_SMBUS_EMUL;
 322 }
 323
 324 static struct i2c_algorithm saa7134_algo = {
 325         .master_xfer   = saa7134_i2c_xfer,
 326         .functionality = functionality,
 327 };
 328
 329 static struct i2c_adapter saa7134_adap_template = {
 330         .owner         = THIS_MODULE,
 331         .name          = "saa7134",
 332         .id            = I2C_HW_SAA7134,
 333         .algo          = &saa7134_algo,
 334 };
 335
 336 static struct i2c_client saa7134_client_template = {
 337         .name   = "saa7134 internal",
 338 };
 339
 340 /* ----------------------------------------------------------- */
 341
 342 static int
 343 saa7134_i2c_eeprom(struct saa7134_dev *dev, unsigned char *eedata, int len)
 344 {
 345         unsigned char buf;
 346         int i,err;
 347
 348         dev->i2c_client.addr = 0xa0 >> 1;
 349         buf = 0;
 350         if (1 != (err = i2c_master_send(&dev->i2c_client,&buf,1))) {
 351                 printk(KERN_INFO "%s: Huh, no eeprom present (err=%d)?\n",
 352                        dev->name,err);
 353                 return -1;
 354         }
 355         if (len != (err = i2c_master_recv(&dev->i2c_client,eedata,len))) {
 356                 printk(KERN_WARNING "%s: i2c eeprom read error (err=%d)\n",
 357                        dev->name,err);
 358                 return -1;
 359         }
 360         for (i = 0; i < len; i++) {
 361                 if (0 == (i % 16))
 362                         printk(KERN_INFO "%s: i2c eeprom %02x:",dev->name,i);
 363                 printk(" %02x",eedata[i]);
 364                 if (15 == (i % 16))
 365                         printk("\n");
 366         }
 367         return 0;
 368 }
 369
 370 static char *i2c_devs[128] = {
 371         [ 0x20      ] = "mpeg encoder (saa6752hs)",
 372         [ 0xa0 >> 1 ] = "eeprom",
 373         [ 0xc0 >> 1 ] = "tuner (analog)",
 374         [ 0x86 >> 1 ] = "tda9887",
 375         [ 0x5a >> 1 ] = "remote control",
 376 };
 377
 378 static void do_i2c_scan(char *name, struct i2c_client *c)
 379 {
 380         unsigned char buf;
 381         int i,rc;
 382
 383         for (i = 0; i < ARRAY_SIZE(i2c_devs); i++) {
 384                 c->addr = i;
 385                 rc = i2c_master_recv(c,&buf,0);
 386                 if (rc < 0)
 387                         continue;
 388                 printk("%s: i2c scan: found device @ 0x%x  [%s]\n",
 389                        name, i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
 390         }
 391 }
 392
 393 int saa7134_i2c_register(struct saa7134_dev *dev)
 394 {
 395         dev->i2c_adap = saa7134_adap_template;
 396         dev->i2c_adap.dev.parent = &dev->pci->dev;
 397         strcpy(dev->i2c_adap.name,dev->name);
 398         dev->i2c_adap.algo_data = dev;
 399         i2c_set_adapdata(&dev->i2c_adap, &dev->v4l2_dev);
 400         i2c_add_adapter(&dev->i2c_adap);
 401
 402         dev->i2c_client = saa7134_client_template;
 403         dev->i2c_client.adapter = &dev->i2c_adap;
 404
 405         saa7134_i2c_eeprom(dev,dev->eedata,sizeof(dev->eedata));
 406         if (i2c_scan)
 407                 do_i2c_scan(dev->name,&dev->i2c_client);
 408
 409         /* Instantiate the IR receiver device, if present */
 410         saa7134_probe_i2c_ir(dev);
 411         return 0;
 412 }
 413
 414 int saa7134_i2c_unregister(struct saa7134_dev *dev)
 415 {
 416         i2c_del_adapter(&dev->i2c_adap);
 417         return 0;
 418 }
 419
 420 /* ----------------------------------------------------------- */
 421 /*
 422  * Local variables:
 423  * c-basic-offset: 8
 424  * End:
 425  */