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

   1 /*
   2  * device driver for philips saa7134 based TV cards
   3  * i2c interface support
   4  *
   5  * (c) 2001,02 Gerd Knorr <kraxel@bytesex.org> [SuSE Labs]
   6  *
   7  *  This program is free software; you can redistribute it and/or modify
   8  *  it under the terms of the GNU General Public License as published by
   9  *  the Free Software Foundation; either version 2 of the License, or
  10  *  (at your option) any later version.
  11  *
  12  *  This program is distributed in the hope that it will be useful,
  13  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *  GNU General Public License for more details.
  16  *
  17  *  You should have received a copy of the GNU General Public License
  18  *  along with this program; if not, write to the Free Software
  19  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20  */
  21
  22 #include <linux/init.h>
  23 #include <linux/list.h>
  24 #include <linux/module.h>
  25 #include <linux/kernel.h>
  26 #include <linux/slab.h>
  27 #include <linux/delay.h>
  28
  29 #include "saa7134-reg.h"
  30 #include "saa7134.h"
  31
  32 /* ----------------------------------------------------------- */
  33
  34 static unsigned int i2c_debug = 0;
  35 MODULE_PARM(i2c_debug,"i");
  36 MODULE_PARM_DESC(i2c_debug,"enable debug messages [i2c]");
  37
  38 static unsigned int i2c_scan = 0;
  39 MODULE_PARM(i2c_scan,"i");
  40 MODULE_PARM_DESC(i2c_scan,"scan i2c bus at insmod time");
  41
  42 #define d1printk if (1 == i2c_debug) printk
  43 #define d2printk if (2 == i2c_debug) printk
  44
  45 #define I2C_WAIT_DELAY  32
  46 #define I2C_WAIT_RETRY  16
  47
  48 /* ----------------------------------------------------------- */
  49
  50 static char *str_i2c_status[] = {
  51         "IDLE", "DONE_STOP", "BUSY", "TO_SCL", "TO_ARB", "DONE_WRITE",
  52         "DONE_READ", "DONE_WRITE_TO", "DONE_READ_TO", "NO_DEVICE",
  53         "NO_ACKN", "BUS_ERR", "ARB_LOST", "SEQ_ERR", "ST_ERR", "SW_ERR"
  54 };
  55
  56 enum i2c_status {
  57         IDLE          = 0,  // no I2C command pending
  58         DONE_STOP     = 1,  // I2C command done and STOP executed
  59         BUSY          = 2,  // executing I2C command
  60         TO_SCL        = 3,  // executing I2C command, time out on clock stretching
  61         TO_ARB        = 4,  // time out on arbitration trial, still trying
  62         DONE_WRITE    = 5,  // I2C command done and awaiting next write command
  63         DONE_READ     = 6,  // I2C command done and awaiting next read command
  64         DONE_WRITE_TO = 7,  // see 5, and time out on status echo
  65         DONE_READ_TO  = 8,  // see 6, and time out on status echo
  66         NO_DEVICE     = 9,  // no acknowledge on device slave address
  67         NO_ACKN       = 10, // no acknowledge after data byte transfer
  68         BUS_ERR       = 11, // bus error
  69         ARB_LOST      = 12, // arbitration lost during transfer
  70         SEQ_ERR       = 13, // erroneous programming sequence
  71         ST_ERR        = 14, // wrong status echoing
  72         SW_ERR        = 15  // software error
  73 };
  74
  75 static char *str_i2c_attr[] = {
  76         "NOP", "STOP", "CONTINUE", "START"
  77 };
  78
  79 enum i2c_attr {
  80         NOP           = 0,  // no operation on I2C bus
  81         STOP          = 1,  // stop condition, no associated byte transfer
  82         CONTINUE      = 2,  // continue with byte transfer
  83         START         = 3   // start condition with byte transfer
  84 };
  85
  86 static inline enum i2c_status i2c_get_status(struct saa7134_dev *dev)
  87 {
  88         enum i2c_status status;
  89
  90         status = saa_readb(SAA7134_I2C_ATTR_STATUS) & 0x0f;
  91         d2printk(KERN_DEBUG "%s: i2c stat <= %s\n",dev->name,
  92                  str_i2c_status[status]);
  93         return status;
  94 }
  95
  96 static inline void i2c_set_status(struct saa7134_dev *dev,
  97                                   enum i2c_status status)
  98 {
  99         d2printk(KERN_DEBUG "%s: i2c stat => %s\n",dev->name,
 100                  str_i2c_status[status]);
 101         saa_andorb(SAA7134_I2C_ATTR_STATUS,0x0f,status);
 102 }
 103
 104 static inline void i2c_set_attr(struct saa7134_dev *dev, enum i2c_attr attr)
 105 {
 106         d2printk(KERN_DEBUG "%s: i2c attr => %s\n",dev->name,
 107                  str_i2c_attr[attr]);
 108         saa_andorb(SAA7134_I2C_ATTR_STATUS,0xc0,attr << 6);
 109 }
 110
 111 static inline int i2c_is_error(enum i2c_status status)
 112 {
 113         switch (status) {
 114         case NO_DEVICE:
 115         case NO_ACKN:
 116         case BUS_ERR:
 117         case ARB_LOST:
 118         case SEQ_ERR:
 119         case ST_ERR:
 120                 return TRUE;
 121         default:
 122                 return FALSE;
 123         }
 124 }
 125
 126 static inline int i2c_is_idle(enum i2c_status status)
 127 {
 128         switch (status) {
 129         case IDLE:
 130         case DONE_STOP:
 131                 return TRUE;
 132         default:
 133                 return FALSE;
 134         }
 135 }
 136
 137 static inline int i2c_is_busy(enum i2c_status status)
 138 {
 139         switch (status) {
 140         case BUSY:
 141                 return TRUE;
 142         default:
 143                 return FALSE;
 144         }
 145 }
 146
 147 static int i2c_is_busy_wait(struct saa7134_dev *dev)
 148 {
 149         enum i2c_status status;
 150         int count;
 151
 152         for (count = 0; count < I2C_WAIT_RETRY; count++) {
 153                 status = i2c_get_status(dev);
 154                 if (!i2c_is_busy(status))
 155                         break;
 156                 saa_wait(I2C_WAIT_DELAY);
 157         }
 158         if (I2C_WAIT_RETRY == count)
 159                 return FALSE;
 160         return TRUE;
 161 }
 162
 163 static int i2c_reset(struct saa7134_dev *dev)
 164 {
 165         enum i2c_status status;
 166         int count;
 167
 168         d2printk(KERN_DEBUG "%s: i2c reset\n",dev->name);
 169         status = i2c_get_status(dev);
 170         if (!i2c_is_error(status))
 171                 return TRUE;
 172         i2c_set_status(dev,status);
 173
 174         for (count = 0; count < I2C_WAIT_RETRY; count++) {
 175                 status = i2c_get_status(dev);
 176                 if (!i2c_is_error(status))
 177                         break;
 178                 udelay(I2C_WAIT_DELAY);
 179         }
 180         if (I2C_WAIT_RETRY == count)
 181                 return FALSE;
 182
 183         if (!i2c_is_idle(status))
 184                 return FALSE;
 185
 186         i2c_set_attr(dev,NOP);
 187         return TRUE;
 188 }
 189
 190 static inline int i2c_send_byte(struct saa7134_dev *dev,
 191                                 enum i2c_attr attr,
 192                                 unsigned char data)
 193 {
 194         enum i2c_status status;
 195         __u32 dword;
 196
 197 #if 0
 198         i2c_set_attr(dev,attr);
 199         saa_writeb(SAA7134_I2C_DATA, data);
 200 #else
 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;
 207         dword |= 0xf0 << 24;
 208         saa_writel(SAA7134_I2C_ATTR_STATUS >> 2, dword);
 209 #endif
 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         d1printk(KERN_DEBUG "%s: i2c xfer:",dev->name);
 250         for (i = 0; i < num; i++) {
 251                 if (!(msgs[i].flags & I2C_M_NOSTART) || 0 == i) {
 252                         /* send address */
 253                         addr  = msgs[i].addr << 1;
 254                         if (msgs[i].flags & I2C_M_RD)
 255                                 addr |= 1;
 256                         d1printk(" < %02x", addr);
 257                         rc = i2c_send_byte(dev,START,addr);
 258                         if (rc < 0)
 259                                  goto err;
 260                 }
 261                 if (msgs[i].flags & I2C_M_RD) {
 262                         /* read bytes */
 263                         for (byte = 0; byte < msgs[i].len; byte++) {
 264                                 d1printk(" =");
 265                                 rc = i2c_recv_byte(dev);
 266                                 if (rc < 0)
 267                                         goto err;
 268                                 d1printk("%02x", rc);
 269                                 msgs[i].buf[byte] = rc;
 270                         }
 271                 } else {
 272                         /* write bytes */
 273                         for (byte = 0; byte < msgs[i].len; byte++) {
 274                                 data = msgs[i].buf[byte];
 275                                 d1printk(" %02x", data);
 276                                 rc = i2c_send_byte(dev,CONTINUE,data);
 277                                 if (rc < 0)
 278                                         goto err;
 279                         }
 280                 }
 281         }
 282         d1printk(" >");
 283         i2c_set_attr(dev,STOP);
 284         rc = -EIO;
 285         if (!i2c_is_busy_wait(dev))
 286                 goto err;
 287         status = i2c_get_status(dev);
 288         if (i2c_is_error(status))
 289                 goto err;
 290
 291         d1printk("\n");
 292         return num;
 293  err:
 294         if (1 == i2c_debug) {
 295                 status = i2c_get_status(dev);
 296                 printk(" ERROR: %s\n",str_i2c_status[status]);
 297         }
 298         return rc;
 299 }
 300
 301 /* ----------------------------------------------------------- */
 302
 303 static int algo_control(struct i2c_adapter *adapter,
 304                         unsigned int cmd, unsigned long arg)
 305 {
 306         return 0;
 307 }
 308
 309 static u32 functionality(struct i2c_adapter *adap)
 310 {
 311         return I2C_FUNC_SMBUS_EMUL;
 312 }
 313
 314 #ifndef I2C_PEC
 315 static void inc_use(struct i2c_adapter *adap)
 316 {
 317         MOD_INC_USE_COUNT;
 318 }
 319
 320 static void dec_use(struct i2c_adapter *adap)
 321 {
 322         MOD_DEC_USE_COUNT;
 323 }
 324 #endif
 325
 326 static int attach_inform(struct i2c_client *client)
 327 {
 328         struct saa7134_dev *dev = client->adapter->algo_data;
 329         int tuner = dev->tuner_type;
 330
 331         saa7134_i2c_call_clients(dev,TUNER_SET_TYPE,&tuner);
 332         return 0;
 333 }
 334
 335 static struct i2c_algorithm saa7134_algo = {
 336         .name          = "saa7134",
 337         .id            = I2C_ALGO_SAA7134,
 338         .master_xfer   = saa7134_i2c_xfer,
 339         .algo_control  = algo_control,
 340         .functionality = functionality,
 341 };
 342
 343 static struct i2c_adapter saa7134_adap_template = {
 344 #ifdef I2C_PEC
 345         .owner         = THIS_MODULE,
 346 #else
 347         .inc_use       = inc_use,
 348         .dec_use       = dec_use,
 349 #endif
 350 #ifdef I2C_CLASS_TV_ANALOG
 351         .class         = I2C_CLASS_TV_ANALOG,
 352 #endif
 353         I2C_DEVNAME("saa7134"),
 354         .id            = I2C_ALGO_SAA7134,
 355         .algo          = &saa7134_algo,
 356         .client_register = attach_inform,
 357 };
 358
 359 static struct i2c_client saa7134_client_template = {
 360         I2C_DEVNAME("saa7134 internal"),
 361         .id        = -1,
 362 };
 363
 364 /* ----------------------------------------------------------- */
 365
 366 static int
 367 saa7134_i2c_eeprom(struct saa7134_dev *dev, unsigned char *eedata, int len)
 368 {
 369         unsigned char buf;
 370         int i,err;
 371
 372         dev->i2c_client.addr = 0xa0 >> 1;
 373         buf = 0;
 374         if (1 != (err = i2c_master_send(&dev->i2c_client,&buf,1))) {
 375                 printk(KERN_INFO "%s: Huh, no eeprom present (err=%d)?\n",
 376                        dev->name,err);
 377                 return -1;
 378         }
 379         if (len != (err = i2c_master_recv(&dev->i2c_client,eedata,len))) {
 380                 printk(KERN_WARNING "%s: i2c eeprom read error (err=%d)\n",
 381                        dev->name,err);
 382                 return -1;
 383         }
 384         for (i = 0; i < len; i++) {
 385                 if (0 == (i % 16))
 386                         printk(KERN_INFO "%s: i2c eeprom %02x:",dev->name,i);
 387                 printk(" %02x",eedata[i]);
 388                 if (15 == (i % 16))
 389                         printk("\n");
 390         }
 391         return 0;
 392 }
 393
 394 static int
 395 saa7134_i2c_scan(struct saa7134_dev *dev)
 396 {
 397         unsigned char buf;
 398         int i,rc;
 399
 400         for (i = 0; i < 256; i+= 2) {
 401                 dev->i2c_client.addr = i >> 1;
 402                 rc = i2c_master_recv(&dev->i2c_client,&buf,0);
 403                 if (rc < 0)
 404                         continue;
 405                 printk("%s: i2c scan: found device @ %x%s\n",
 406                        dev->name, i, (i == 0xa0) ? " [eeprom]" : "");
 407         }
 408         return 0;
 409 }
 410
 411 void saa7134_i2c_call_clients(struct saa7134_dev *dev,
 412                               unsigned int cmd, void *arg)
 413 {
 414         BUG_ON(NULL == dev->i2c_adap.algo_data);
 415         i2c_clients_command(&dev->i2c_adap, cmd, arg);
 416 }
 417
 418 int saa7134_i2c_register(struct saa7134_dev *dev)
 419 {
 420         dev->i2c_adap = saa7134_adap_template;
 421         dev->i2c_adap.dev.parent = &dev->pci->dev;
 422         strcpy(dev->i2c_adap.name,dev->name);
 423         dev->i2c_adap.algo_data = dev;
 424         i2c_add_adapter(&dev->i2c_adap);
 425
 426         dev->i2c_client = saa7134_client_template;
 427         dev->i2c_client.adapter = &dev->i2c_adap;
 428
 429         saa7134_i2c_eeprom(dev,dev->eedata,sizeof(dev->eedata));
 430         if (i2c_scan)
 431                 saa7134_i2c_scan(dev);
 432         return 0;
 433 }
 434
 435 int saa7134_i2c_unregister(struct saa7134_dev *dev)
 436 {
 437         i2c_del_adapter(&dev->i2c_adap);
 438         return 0;
 439 }
 440
 441 /* ----------------------------------------------------------- */
 442 /*
 443  * Local variables:
 444  * c-basic-offset: 8
 445  * End:
 446  */