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/delay.h>
  28
  29 #include "saa7134-reg.h"
  30 #include "saa7134.h"
  31 #include <media/v4l2-common.h>
  32
  33 /* ----------------------------------------------------------- */
  34
  35 static unsigned int i2c_debug;
  36 module_param(i2c_debug, int, 0644);
  37 MODULE_PARM_DESC(i2c_debug,"enable debug messages [i2c]");
  38
  39 static unsigned int i2c_scan;
  40 module_param(i2c_scan, int, 0444);
  41 MODULE_PARM_DESC(i2c_scan,"scan i2c bus at insmod time");
  42
  43 #define d1printk if (1 == i2c_debug) printk
  44 #define d2printk if (2 == i2c_debug) printk
  45
  46 #define I2C_WAIT_DELAY  32
  47 #define I2C_WAIT_RETRY  16
  48
  49 /* ----------------------------------------------------------- */
  50
  51 static char *str_i2c_status[] = {
  52         "IDLE", "DONE_STOP", "BUSY", "TO_SCL", "TO_ARB", "DONE_WRITE",
  53         "DONE_READ", "DONE_WRITE_TO", "DONE_READ_TO", "NO_DEVICE",
  54         "NO_ACKN", "BUS_ERR", "ARB_LOST", "SEQ_ERR", "ST_ERR", "SW_ERR"
  55 };
  56
  57 enum i2c_status {
  58         IDLE          = 0,  // no I2C command pending
  59         DONE_STOP     = 1,  // I2C command done and STOP executed
  60         BUSY          = 2,  // executing I2C command
  61         TO_SCL        = 3,  // executing I2C command, time out on clock stretching
  62         TO_ARB        = 4,  // time out on arbitration trial, still trying
  63         DONE_WRITE    = 5,  // I2C command done and awaiting next write command
  64         DONE_READ     = 6,  // I2C command done and awaiting next read command
  65         DONE_WRITE_TO = 7,  // see 5, and time out on status echo
  66         DONE_READ_TO  = 8,  // see 6, and time out on status echo
  67         NO_DEVICE     = 9,  // no acknowledge on device slave address
  68         NO_ACKN       = 10, // no acknowledge after data byte transfer
  69         BUS_ERR       = 11, // bus error
  70         ARB_LOST      = 12, // arbitration lost during transfer
  71         SEQ_ERR       = 13, // erroneous programming sequence
  72         ST_ERR        = 14, // wrong status echoing
  73         SW_ERR        = 15  // software error
  74 };
  75
  76 static char *str_i2c_attr[] = {
  77         "NOP", "STOP", "CONTINUE", "START"
  78 };
  79
  80 enum i2c_attr {
  81         NOP           = 0,  // no operation on I2C bus
  82         STOP          = 1,  // stop condition, no associated byte transfer
  83         CONTINUE      = 2,  // continue with byte transfer
  84         START         = 3   // start condition with byte transfer
  85 };
  86
  87 static inline enum i2c_status i2c_get_status(struct saa7134_dev *dev)
  88 {
  89         enum i2c_status status;
  90
  91         status = saa_readb(SAA7134_I2C_ATTR_STATUS) & 0x0f;
  92         d2printk(KERN_DEBUG "%s: i2c stat <= %s\n",dev->name,
  93                  str_i2c_status[status]);
  94         return status;
  95 }
  96
  97 static inline void i2c_set_status(struct saa7134_dev *dev,
  98                                   enum i2c_status status)
  99 {
 100         d2printk(KERN_DEBUG "%s: i2c stat => %s\n",dev->name,
 101                  str_i2c_status[status]);
 102         saa_andorb(SAA7134_I2C_ATTR_STATUS,0x0f,status);
 103 }
 104
 105 static inline void i2c_set_attr(struct saa7134_dev *dev, enum i2c_attr attr)
 106 {
 107         d2printk(KERN_DEBUG "%s: i2c attr => %s\n",dev->name,
 108                  str_i2c_attr[attr]);
 109         saa_andorb(SAA7134_I2C_ATTR_STATUS,0xc0,attr << 6);
 110 }
 111
 112 static inline int i2c_is_error(enum i2c_status status)
 113 {
 114         switch (status) {
 115         case NO_DEVICE:
 116         case NO_ACKN:
 117         case BUS_ERR:
 118         case ARB_LOST:
 119         case SEQ_ERR:
 120         case ST_ERR:
 121                 return true;
 122         default:
 123                 return false;
 124         }
 125 }
 126
 127 static inline int i2c_is_idle(enum i2c_status status)
 128 {
 129         switch (status) {
 130         case IDLE:
 131         case DONE_STOP:
 132                 return true;
 133         default:
 134                 return false;
 135         }
 136 }
 137
 138 static inline int i2c_is_busy(enum i2c_status status)
 139 {
 140         switch (status) {
 141         case BUSY:
 142         case TO_SCL:
 143         case TO_ARB:
 144                 return true;
 145         default:
 146                 return false;
 147         }
 148 }
 149
 150 static int i2c_is_busy_wait(struct saa7134_dev *dev)
 151 {
 152         enum i2c_status status;
 153         int count;
 154
 155         for (count = 0; count < I2C_WAIT_RETRY; count++) {
 156                 status = i2c_get_status(dev);
 157                 if (!i2c_is_busy(status))
 158                         break;
 159                 saa_wait(I2C_WAIT_DELAY);
 160         }
 161         if (I2C_WAIT_RETRY == count)
 162                 return false;
 163         return true;
 164 }
 165
 166 static int i2c_reset(struct saa7134_dev *dev)
 167 {
 168         enum i2c_status status;
 169         int count;
 170
 171         d2printk(KERN_DEBUG "%s: i2c reset\n",dev->name);
 172         status = i2c_get_status(dev);
 173         if (!i2c_is_error(status))
 174                 return true;
 175         i2c_set_status(dev,status);
 176
 177         for (count = 0; count < I2C_WAIT_RETRY; count++) {
 178                 status = i2c_get_status(dev);
 179                 if (!i2c_is_error(status))
 180                         break;
 181                 udelay(I2C_WAIT_DELAY);
 182         }
 183         if (I2C_WAIT_RETRY == count)
 184                 return false;
 185
 186         if (!i2c_is_idle(status))
 187                 return false;
 188
 189         i2c_set_attr(dev,NOP);
 190         return true;
 191 }
 192
 193 static inline int i2c_send_byte(struct saa7134_dev *dev,
 194                                 enum i2c_attr attr,
 195                                 unsigned char data)
 196 {
 197         enum i2c_status status;
 198         __u32 dword;
 199
 200         /* have to write both attr + data in one 32bit word */
 201         dword  = saa_readl(SAA7134_I2C_ATTR_STATUS >> 2);
 202         dword &= 0x0f;
 203         dword |= (attr << 6);
 204         dword |= ((__u32)data << 8);
 205         dword |= 0x00 << 16;  /* 100 kHz */
 206 //      dword |= 0x40 << 16;  /* 400 kHz */
 207         dword |= 0xf0 << 24;
 208         saa_writel(SAA7134_I2C_ATTR_STATUS >> 2, dword);
 209         d2printk(KERN_DEBUG "%s: i2c data => 0x%x\n",dev->name,data);
 210
 211         if (!i2c_is_busy_wait(dev))
 212                 return -EIO;
 213         status = i2c_get_status(dev);
 214         if (i2c_is_error(status))
 215                 return -EIO;
 216         return 0;
 217 }
 218
 219 static inline int i2c_recv_byte(struct saa7134_dev *dev)
 220 {
 221         enum i2c_status status;
 222         unsigned char data;
 223
 224         i2c_set_attr(dev,CONTINUE);
 225         if (!i2c_is_busy_wait(dev))
 226                 return -EIO;
 227         status = i2c_get_status(dev);
 228         if (i2c_is_error(status))
 229                 return -EIO;
 230         data = saa_readb(SAA7134_I2C_DATA);
 231         d2printk(KERN_DEBUG "%s: i2c data <= 0x%x\n",dev->name,data);
 232         return data;
 233 }
 234
 235 static int saa7134_i2c_xfer(struct i2c_adapter *i2c_adap,
 236                             struct i2c_msg *msgs, int num)
 237 {
 238         struct saa7134_dev *dev = i2c_adap->algo_data;
 239         enum i2c_status status;
 240         unsigned char data;
 241         int addr,rc,i,byte;
 242
 243         status = i2c_get_status(dev);
 244         if (!i2c_is_idle(status))
 245                 if (!i2c_reset(dev))
 246                         return -EIO;
 247
 248         d2printk("start xfer\n");
 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                         d2printk("send address\n");
 254                         addr  = msgs[i].addr << 1;
 255                         if (msgs[i].flags & I2C_M_RD)
 256                                 addr |= 1;
 257                         if (i > 0 && msgs[i].flags & I2C_M_RD && msgs[i].addr != 0x40) {
 258                                 /* workaround for a saa7134 i2c bug
 259                                  * needed to talk to the mt352 demux
 260                                  * thanks to pinnacle for the hint */
 261                                 int quirk = 0xfe;
 262                                 d1printk(" [%02x quirk]",quirk);
 263                                 i2c_send_byte(dev,START,quirk);
 264                                 i2c_recv_byte(dev);
 265                         }
 266                         d1printk(" < %02x", addr);
 267                         rc = i2c_send_byte(dev,START,addr);
 268                         if (rc < 0)
 269                                  goto err;
 270                 }
 271                 if (msgs[i].flags & I2C_M_RD) {
 272                         /* read bytes */
 273                         d2printk("read bytes\n");
 274                         for (byte = 0; byte < msgs[i].len; byte++) {
 275                                 d1printk(" =");
 276                                 rc = i2c_recv_byte(dev);
 277                                 if (rc < 0)
 278                                         goto err;
 279                                 d1printk("%02x", rc);
 280                                 msgs[i].buf[byte] = rc;
 281                         }
 282                 } else {
 283                         /* write bytes */
 284                         d2printk("write bytes\n");
 285                         for (byte = 0; byte < msgs[i].len; byte++) {
 286                                 data = msgs[i].buf[byte];
 287                                 d1printk(" %02x", data);
 288                                 rc = i2c_send_byte(dev,CONTINUE,data);
 289                                 if (rc < 0)
 290                                         goto err;
 291                         }
 292                 }
 293         }
 294         d2printk("xfer done\n");
 295         d1printk(" >");
 296         i2c_set_attr(dev,STOP);
 297         rc = -EIO;
 298         if (!i2c_is_busy_wait(dev))
 299                 goto err;
 300         status = i2c_get_status(dev);
 301         if (i2c_is_error(status))
 302                 goto err;
 303         /* ensure that the bus is idle for at least one bit slot */
 304         msleep(1);
 305
 306         d1printk("\n");
 307         return num;
 308  err:
 309         if (1 == i2c_debug) {
 310                 status = i2c_get_status(dev);
 311                 printk(" ERROR: %s\n",str_i2c_status[status]);
 312         }
 313         return rc;
 314 }
 315
 316 /* ----------------------------------------------------------- */
 317
 318 static u32 functionality(struct i2c_adapter *adap)
 319 {
 320         return I2C_FUNC_SMBUS_EMUL;
 321 }
 322
 323 static struct i2c_algorithm saa7134_algo = {
 324         .master_xfer   = saa7134_i2c_xfer,
 325         .functionality = functionality,
 326 };
 327
 328 static struct i2c_adapter saa7134_adap_template = {
 329         .owner         = THIS_MODULE,
 330         .name          = "saa7134",
 331         .algo          = &saa7134_algo,
 332 };
 333
 334 static struct i2c_client saa7134_client_template = {
 335         .name   = "saa7134 internal",
 336 };
 337
 338 /* ----------------------------------------------------------- */
 339
 340 static int
 341 saa7134_i2c_eeprom(struct saa7134_dev *dev, unsigned char *eedata, int len)
 342 {
 343         unsigned char buf;
 344         int i,err;
 345
 346         dev->i2c_client.addr = 0xa0 >> 1;
 347         buf = 0;
 348         if (1 != (err = i2c_master_send(&dev->i2c_client,&buf,1))) {
 349                 printk(KERN_INFO "%s: Huh, no eeprom present (err=%d)?\n",
 350                        dev->name,err);
 351                 return -1;
 352         }
 353         if (len != (err = i2c_master_recv(&dev->i2c_client,eedata,len))) {
 354                 printk(KERN_WARNING "%s: i2c eeprom read error (err=%d)\n",
 355                        dev->name,err);
 356                 return -1;
 357         }
 358         for (i = 0; i < len; i++) {
 359                 if (0 == (i % 16))
 360                         printk(KERN_INFO "%s: i2c eeprom %02x:",dev->name,i);
 361                 printk(" %02x",eedata[i]);
 362                 if (15 == (i % 16))
 363                         printk("\n");
 364         }
 365         return 0;
 366 }
 367
 368 static char *i2c_devs[128] = {
 369         [ 0x20      ] = "mpeg encoder (saa6752hs)",
 370         [ 0xa0 >> 1 ] = "eeprom",
 371         [ 0xc0 >> 1 ] = "tuner (analog)",
 372         [ 0x86 >> 1 ] = "tda9887",
 373         [ 0x5a >> 1 ] = "remote control",
 374 };
 375
 376 static void do_i2c_scan(char *name, struct i2c_client *c)
 377 {
 378         unsigned char buf;
 379         int i,rc;
 380
 381         for (i = 0; i < ARRAY_SIZE(i2c_devs); i++) {
 382                 c->addr = i;
 383                 rc = i2c_master_recv(c,&buf,0);
 384                 if (rc < 0)
 385                         continue;
 386                 printk("%s: i2c scan: found device @ 0x%x  [%s]\n",
 387                        name, i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
 388         }
 389 }
 390
 391 int saa7134_i2c_register(struct saa7134_dev *dev)
 392 {
 393         dev->i2c_adap = saa7134_adap_template;
 394         dev->i2c_adap.dev.parent = &dev->pci->dev;
 395         strcpy(dev->i2c_adap.name,dev->name);
 396         dev->i2c_adap.algo_data = dev;
 397         i2c_set_adapdata(&dev->i2c_adap, &dev->v4l2_dev);
 398         i2c_add_adapter(&dev->i2c_adap);
 399
 400         dev->i2c_client = saa7134_client_template;
 401         dev->i2c_client.adapter = &dev->i2c_adap;
 402
 403         saa7134_i2c_eeprom(dev,dev->eedata,sizeof(dev->eedata));
 404         if (i2c_scan)
 405                 do_i2c_scan(dev->name,&dev->i2c_client);
 406
 407         /* Instantiate the IR receiver device, if present */
 408         saa7134_probe_i2c_ir(dev);
 409         return 0;
 410 }
 411
 412 int saa7134_i2c_unregister(struct saa7134_dev *dev)
 413 {
 414         i2c_del_adapter(&dev->i2c_adap);
 415         return 0;
 416 }
 417
 418 /* ----------------------------------------------------------- */
 419 /*
 420  * Local variables:
 421  * c-basic-offset: 8
 422  * End:
 423  */