linux/drivers/media/pci/bt8xx/bttv-i2c.c
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   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
  29static int i2c_debug;
  30static int i2c_hw;
  31static int i2c_scan;
  32module_param(i2c_debug, int, 0644);
  33MODULE_PARM_DESC(i2c_debug, "configure i2c debug level");
  34module_param(i2c_hw,    int, 0444);
  35MODULE_PARM_DESC(i2c_hw, "force use of hardware i2c support, instead of software bitbang");
  36module_param(i2c_scan,  int, 0444);
  37MODULE_PARM_DESC(i2c_scan,"scan i2c bus at insmod time");
  38
  39static unsigned int i2c_udelay = 5;
  40module_param(i2c_udelay, int, 0444);
  41MODULE_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
  46static 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
  58static 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
  70static 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
  79static 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
  88static 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
 100static u32 functionality(struct i2c_adapter *adap)
 101{
 102        return I2C_FUNC_SMBUS_EMUL;
 103}
 104
 105static int
 106bttv_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
 124static int
 125bttv_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
 174static int
 175bttv_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
 220static 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
 250static 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 */
 259int 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 */
 284int 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 */
 301void 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
 310static 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
 320static 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 */
 336int 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
 384int 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}
 391