drivers/media/pci/bt8xx/bttv-i2c.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3
   4     bttv-i2c.c  --  all the i2c code is here
   5
   6     bttv - Bt848 frame grabber driver
   7
   8     Copyright (C) 1996,97,98 Ralph  Metzler (rjkm@thp.uni-koeln.de)
   9                            & Marcus Metzler (mocm@thp.uni-koeln.de)
  10     (c) 1999-2003 Gerd Knorr <kraxel@bytesex.org>
  11
  12     (c) 2005 Mauro Carvalho Chehab <mchehab@kernel.org>
  13         - Multituner support and i2c address binding
  14
  15
  16 */
  17
  18 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  19
  20 #include <linux/module.h>
  21 #include <linux/init.h>
  22 #include <linux/delay.h>
  23
  24 #include "bttvp.h"
  25 #include <media/v4l2-common.h>
  26 #include <linux/jiffies.h>
  27 #include <asm/io.h>
  28
  29 static int i2c_debug;
  30 static int i2c_hw;
  31 static int i2c_scan;
  32 module_param(i2c_debug, int, 0644);
  33 MODULE_PARM_DESC(i2c_debug, "configure i2c debug level");
  34 module_param(i2c_hw,    int, 0444);
  35 MODULE_PARM_DESC(i2c_hw, "force use of hardware i2c support, instead of software bitbang");
  36 module_param(i2c_scan,  int, 0444);
  37 MODULE_PARM_DESC(i2c_scan,"scan i2c bus at insmod time");
  38
  39 static unsigned int i2c_udelay = 5;
  40 module_param(i2c_udelay, int, 0444);
  41 MODULE_PARM_DESC(i2c_udelay, "soft i2c delay at insmod time, in usecs (should be 5 or higher). Lower value means higher bus speed.");
  42
  43 /* ----------------------------------------------------------------------- */
  44 /* I2C functions - bitbanging adapter (software i2c)                       */
  45
  46 static void bttv_bit_setscl(void *data, int state)
  47 {
  48         struct bttv *btv = (struct bttv*)data;
  49
  50         if (state)
  51                 btv->i2c_state |= 0x02;
  52         else
  53                 btv->i2c_state &= ~0x02;
  54         btwrite(btv->i2c_state, BT848_I2C);
  55         btread(BT848_I2C);
  56 }
  57
  58 static void bttv_bit_setsda(void *data, int state)
  59 {
  60         struct bttv *btv = (struct bttv*)data;
  61
  62         if (state)
  63                 btv->i2c_state |= 0x01;
  64         else
  65                 btv->i2c_state &= ~0x01;
  66         btwrite(btv->i2c_state, BT848_I2C);
  67         btread(BT848_I2C);
  68 }
  69
  70 static int bttv_bit_getscl(void *data)
  71 {
  72         struct bttv *btv = (struct bttv*)data;
  73         int state;
  74
  75         state = btread(BT848_I2C) & 0x02 ? 1 : 0;
  76         return state;
  77 }
  78
  79 static int bttv_bit_getsda(void *data)
  80 {
  81         struct bttv *btv = (struct bttv*)data;
  82         int state;
  83
  84         state = btread(BT848_I2C) & 0x01;
  85         return state;
  86 }
  87
  88 static const struct i2c_algo_bit_data bttv_i2c_algo_bit_template = {
  89         .setsda  = bttv_bit_setsda,
  90         .setscl  = bttv_bit_setscl,
  91         .getsda  = bttv_bit_getsda,
  92         .getscl  = bttv_bit_getscl,
  93         .udelay  = 16,
  94         .timeout = 200,
  95 };
  96
  97 /* ----------------------------------------------------------------------- */
  98 /* I2C functions - hardware i2c                                            */
  99
 100 static u32 functionality(struct i2c_adapter *adap)
 101 {
 102         return I2C_FUNC_SMBUS_EMUL;
 103 }
 104
 105 static int
 106 bttv_i2c_wait_done(struct bttv *btv)
 107 {
 108         int rc = 0;
 109
 110         /* timeout */
 111         if (wait_event_interruptible_timeout(btv->i2c_queue,
 112             btv->i2c_done, msecs_to_jiffies(85)) == -ERESTARTSYS)
 113                 rc = -EIO;
 114
 115         if (btv->i2c_done & BT848_INT_RACK)
 116                 rc = 1;
 117         btv->i2c_done = 0;
 118         return rc;
 119 }
 120
 121 #define I2C_HW (BT878_I2C_MODE  | BT848_I2C_SYNC |\
 122                 BT848_I2C_SCL | BT848_I2C_SDA)
 123
 124 static int
 125 bttv_i2c_sendbytes(struct bttv *btv, const struct i2c_msg *msg, int last)
 126 {
 127         u32 xmit;
 128         int retval,cnt;
 129
 130         /* sanity checks */
 131         if (0 == msg->len)
 132                 return -EINVAL;
 133
 134         /* start, address + first byte */
 135         xmit = (msg->addr << 25) | (msg->buf[0] << 16) | I2C_HW;
 136         if (msg->len > 1 || !last)
 137                 xmit |= BT878_I2C_NOSTOP;
 138         btwrite(xmit, BT848_I2C);
 139         retval = bttv_i2c_wait_done(btv);
 140         if (retval < 0)
 141                 goto err;
 142         if (retval == 0)
 143                 goto eio;
 144         if (i2c_debug) {
 145                 pr_cont(" <W %02x %02x", msg->addr << 1, msg->buf[0]);
 146         }
 147
 148         for (cnt = 1; cnt < msg->len; cnt++ ) {
 149                 /* following bytes */
 150                 xmit = (msg->buf[cnt] << 24) | I2C_HW | BT878_I2C_NOSTART;
 151                 if (cnt < msg->len-1 || !last)
 152                         xmit |= BT878_I2C_NOSTOP;
 153                 btwrite(xmit, BT848_I2C);
 154                 retval = bttv_i2c_wait_done(btv);
 155                 if (retval < 0)
 156                         goto err;
 157                 if (retval == 0)
 158                         goto eio;
 159                 if (i2c_debug)
 160                         pr_cont(" %02x", msg->buf[cnt]);
 161         }
 162         if (i2c_debug && !(xmit & BT878_I2C_NOSTOP))
 163                 pr_cont(">\n");
 164         return msg->len;
 165
 166  eio:
 167         retval = -EIO;
 168  err:
 169         if (i2c_debug)
 170                 pr_cont(" ERR: %d\n",retval);
 171         return retval;
 172 }
 173
 174 static int
 175 bttv_i2c_readbytes(struct bttv *btv, const struct i2c_msg *msg, int last)
 176 {
 177         u32 xmit;
 178         u32 cnt;
 179         int retval;
 180
 181         for (cnt = 0; cnt < msg->len; cnt++) {
 182                 xmit = (msg->addr << 25) | (1 << 24) | I2C_HW;
 183                 if (cnt < msg->len-1)
 184                         xmit |= BT848_I2C_W3B;
 185                 if (cnt < msg->len-1 || !last)
 186                         xmit |= BT878_I2C_NOSTOP;
 187                 if (cnt)
 188                         xmit |= BT878_I2C_NOSTART;
 189
 190                 if (i2c_debug) {
 191                         if (!(xmit & BT878_I2C_NOSTART))
 192                                 pr_cont(" <R %02x", (msg->addr << 1) +1);
 193                 }
 194
 195                 btwrite(xmit, BT848_I2C);
 196                 retval = bttv_i2c_wait_done(btv);
 197                 if (retval < 0)
 198                         goto err;
 199                 if (retval == 0)
 200                         goto eio;
 201                 msg->buf[cnt] = ((u32)btread(BT848_I2C) >> 8) & 0xff;
 202                 if (i2c_debug) {
 203                         pr_cont(" =%02x", msg->buf[cnt]);
 204                 }
 205                 if (i2c_debug && !(xmit & BT878_I2C_NOSTOP))
 206                         pr_cont(" >\n");
 207         }
 208
 209
 210         return msg->len;
 211
 212  eio:
 213         retval = -EIO;
 214  err:
 215         if (i2c_debug)
 216                 pr_cont(" ERR: %d\n",retval);
 217         return retval;
 218 }
 219
 220 static int bttv_i2c_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num)
 221 {
 222         struct v4l2_device *v4l2_dev = i2c_get_adapdata(i2c_adap);
 223         struct bttv *btv = to_bttv(v4l2_dev);
 224         int retval = 0;
 225         int i;
 226
 227         if (i2c_debug)
 228                 pr_debug("bt-i2c:");
 229
 230         btwrite(BT848_INT_I2CDONE|BT848_INT_RACK, BT848_INT_STAT);
 231         for (i = 0 ; i < num; i++) {
 232                 if (msgs[i].flags & I2C_M_RD) {
 233                         /* read */
 234                         retval = bttv_i2c_readbytes(btv, &msgs[i], i+1 == num);
 235                         if (retval < 0)
 236                                 goto err;
 237                 } else {
 238                         /* write */
 239                         retval = bttv_i2c_sendbytes(btv, &msgs[i], i+1 == num);
 240                         if (retval < 0)
 241                                 goto err;
 242                 }
 243         }
 244         return num;
 245
 246  err:
 247         return retval;
 248 }
 249
 250 static const struct i2c_algorithm bttv_algo = {
 251         .master_xfer   = bttv_i2c_xfer,
 252         .functionality = functionality,
 253 };
 254
 255 /* ----------------------------------------------------------------------- */
 256 /* I2C functions - common stuff                                            */
 257
 258 /* read I2C */
 259 int bttv_I2CRead(struct bttv *btv, unsigned char addr, char *probe_for)
 260 {
 261         unsigned char buffer = 0;
 262
 263         if (0 != btv->i2c_rc)
 264                 return -1;
 265         if (bttv_verbose && NULL != probe_for)
 266                 pr_info("%d: i2c: checking for %s @ 0x%02x... ",
 267                         btv->c.nr, probe_for, addr);
 268         btv->i2c_client.addr = addr >> 1;
 269         if (1 != i2c_master_recv(&btv->i2c_client, &buffer, 1)) {
 270                 if (NULL != probe_for) {
 271                         if (bttv_verbose)
 272                                 pr_cont("not found\n");
 273                 } else
 274                         pr_warn("%d: i2c read 0x%x: error\n",
 275                                 btv->c.nr, addr);
 276                 return -1;
 277         }
 278         if (bttv_verbose && NULL != probe_for)
 279                 pr_cont("found\n");
 280         return buffer;
 281 }
 282
 283 /* write I2C */
 284 int bttv_I2CWrite(struct bttv *btv, unsigned char addr, unsigned char b1,
 285                     unsigned char b2, int both)
 286 {
 287         unsigned char buffer[2];
 288         int bytes = both ? 2 : 1;
 289
 290         if (0 != btv->i2c_rc)
 291                 return -1;
 292         btv->i2c_client.addr = addr >> 1;
 293         buffer[0] = b1;
 294         buffer[1] = b2;
 295         if (bytes != i2c_master_send(&btv->i2c_client, buffer, bytes))
 296                 return -1;
 297         return 0;
 298 }
 299
 300 /* read EEPROM content */
 301 void bttv_readee(struct bttv *btv, unsigned char *eedata, int addr)
 302 {
 303         memset(eedata, 0, 256);
 304         if (0 != btv->i2c_rc)
 305                 return;
 306         btv->i2c_client.addr = addr >> 1;
 307         tveeprom_read(&btv->i2c_client, eedata, 256);
 308 }
 309
 310 static char *i2c_devs[128] = {
 311         [ 0x1c >> 1 ] = "lgdt330x",
 312         [ 0x30 >> 1 ] = "IR (hauppauge)",
 313         [ 0x80 >> 1 ] = "msp34xx",
 314         [ 0x86 >> 1 ] = "tda9887",
 315         [ 0xa0 >> 1 ] = "eeprom",
 316         [ 0xc0 >> 1 ] = "tuner (analog)",
 317         [ 0xc2 >> 1 ] = "tuner (analog)",
 318 };
 319
 320 static void do_i2c_scan(char *name, struct i2c_client *c)
 321 {
 322         unsigned char buf;
 323         int i,rc;
 324
 325         for (i = 0; i < ARRAY_SIZE(i2c_devs); i++) {
 326                 c->addr = i;
 327                 rc = i2c_master_recv(c,&buf,0);
 328                 if (rc < 0)
 329                         continue;
 330                 pr_info("%s: i2c scan: found device @ 0x%x  [%s]\n",
 331                         name, i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
 332         }
 333 }
 334
 335 /* init + register i2c adapter */
 336 int init_bttv_i2c(struct bttv *btv)
 337 {
 338         strscpy(btv->i2c_client.name, "bttv internal", I2C_NAME_SIZE);
 339
 340         if (i2c_hw)
 341                 btv->use_i2c_hw = 1;
 342         if (btv->use_i2c_hw) {
 343                 /* bt878 */
 344                 strscpy(btv->c.i2c_adap.name, "bt878",
 345                         sizeof(btv->c.i2c_adap.name));
 346                 btv->c.i2c_adap.algo = &bttv_algo;
 347         } else {
 348                 /* bt848 */
 349         /* Prevents usage of invalid delay values */
 350                 if (i2c_udelay<5)
 351                         i2c_udelay=5;
 352
 353                 strscpy(btv->c.i2c_adap.name, "bttv",
 354                         sizeof(btv->c.i2c_adap.name));
 355                 btv->i2c_algo = bttv_i2c_algo_bit_template;
 356                 btv->i2c_algo.udelay = i2c_udelay;
 357                 btv->i2c_algo.data = btv;
 358                 btv->c.i2c_adap.algo_data = &btv->i2c_algo;
 359         }
 360         btv->c.i2c_adap.owner = THIS_MODULE;
 361
 362         btv->c.i2c_adap.dev.parent = &btv->c.pci->dev;
 363         snprintf(btv->c.i2c_adap.name, sizeof(btv->c.i2c_adap.name),
 364                  "bt%d #%d [%s]", btv->id, btv->c.nr,
 365                  btv->use_i2c_hw ? "hw" : "sw");
 366
 367         i2c_set_adapdata(&btv->c.i2c_adap, &btv->c.v4l2_dev);
 368         btv->i2c_client.adapter = &btv->c.i2c_adap;
 369
 370
 371         if (btv->use_i2c_hw) {
 372                 btv->i2c_rc = i2c_add_adapter(&btv->c.i2c_adap);
 373         } else {
 374                 bttv_bit_setscl(btv,1);
 375                 bttv_bit_setsda(btv,1);
 376                 btv->i2c_rc = i2c_bit_add_bus(&btv->c.i2c_adap);
 377         }
 378         if (0 == btv->i2c_rc && i2c_scan)
 379                 do_i2c_scan(btv->c.v4l2_dev.name, &btv->i2c_client);
 380
 381         return btv->i2c_rc;
 382 }
 383
 384 int fini_bttv_i2c(struct bttv *btv)
 385 {
 386         if (btv->i2c_rc == 0)
 387                 i2c_del_adapter(&btv->c.i2c_adap);
 388
 389         return 0;
 390 }