linux/drivers/media/pci/bt8xx/bttv-i2c.c
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   1/*
   2
   3    bttv-i2c.c  --  all the i2c code is here
   4
   5    bttv - Bt848 frame grabber driver
   6
   7    Copyright (C) 1996,97,98 Ralph  Metzler (rjkm@thp.uni-koeln.de)
   8                           & Marcus Metzler (mocm@thp.uni-koeln.de)
   9    (c) 1999-2003 Gerd Knorr <kraxel@bytesex.org>
  10
  11    (c) 2005 Mauro Carvalho Chehab <mchehab@infradead.org>
  12        - Multituner support and i2c address binding
  13
  14    This program is free software; you can redistribute it and/or modify
  15    it under the terms of the GNU General Public License as published by
  16    the Free Software Foundation; either version 2 of the License, or
  17    (at your option) any later version.
  18
  19    This program is distributed in the hope that it will be useful,
  20    but WITHOUT ANY WARRANTY; without even the implied warranty of
  21    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22    GNU General Public License for more details.
  23
  24    You should have received a copy of the GNU General Public License
  25    along with this program; if not, write to the Free Software
  26    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  27
  28*/
  29
  30#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  31
  32#include <linux/module.h>
  33#include <linux/init.h>
  34#include <linux/delay.h>
  35
  36#include "bttvp.h"
  37#include <media/v4l2-common.h>
  38#include <linux/jiffies.h>
  39#include <asm/io.h>
  40
  41static int i2c_debug;
  42static int i2c_hw;
  43static int i2c_scan;
  44module_param(i2c_debug, int, 0644);
  45MODULE_PARM_DESC(i2c_debug, "configure i2c debug level");
  46module_param(i2c_hw,    int, 0444);
  47MODULE_PARM_DESC(i2c_hw, "force use of hardware i2c support, instead of software bitbang");
  48module_param(i2c_scan,  int, 0444);
  49MODULE_PARM_DESC(i2c_scan,"scan i2c bus at insmod time");
  50
  51static unsigned int i2c_udelay = 5;
  52module_param(i2c_udelay, int, 0444);
  53MODULE_PARM_DESC(i2c_udelay, "soft i2c delay at insmod time, in usecs (should be 5 or higher). Lower value means higher bus speed.");
  54
  55/* ----------------------------------------------------------------------- */
  56/* I2C functions - bitbanging adapter (software i2c)                       */
  57
  58static void bttv_bit_setscl(void *data, int state)
  59{
  60        struct bttv *btv = (struct bttv*)data;
  61
  62        if (state)
  63                btv->i2c_state |= 0x02;
  64        else
  65                btv->i2c_state &= ~0x02;
  66        btwrite(btv->i2c_state, BT848_I2C);
  67        btread(BT848_I2C);
  68}
  69
  70static void bttv_bit_setsda(void *data, int state)
  71{
  72        struct bttv *btv = (struct bttv*)data;
  73
  74        if (state)
  75                btv->i2c_state |= 0x01;
  76        else
  77                btv->i2c_state &= ~0x01;
  78        btwrite(btv->i2c_state, BT848_I2C);
  79        btread(BT848_I2C);
  80}
  81
  82static int bttv_bit_getscl(void *data)
  83{
  84        struct bttv *btv = (struct bttv*)data;
  85        int state;
  86
  87        state = btread(BT848_I2C) & 0x02 ? 1 : 0;
  88        return state;
  89}
  90
  91static int bttv_bit_getsda(void *data)
  92{
  93        struct bttv *btv = (struct bttv*)data;
  94        int state;
  95
  96        state = btread(BT848_I2C) & 0x01;
  97        return state;
  98}
  99
 100static struct i2c_algo_bit_data bttv_i2c_algo_bit_template = {
 101        .setsda  = bttv_bit_setsda,
 102        .setscl  = bttv_bit_setscl,
 103        .getsda  = bttv_bit_getsda,
 104        .getscl  = bttv_bit_getscl,
 105        .udelay  = 16,
 106        .timeout = 200,
 107};
 108
 109/* ----------------------------------------------------------------------- */
 110/* I2C functions - hardware i2c                                            */
 111
 112static u32 functionality(struct i2c_adapter *adap)
 113{
 114        return I2C_FUNC_SMBUS_EMUL;
 115}
 116
 117static int
 118bttv_i2c_wait_done(struct bttv *btv)
 119{
 120        int rc = 0;
 121
 122        /* timeout */
 123        if (wait_event_interruptible_timeout(btv->i2c_queue,
 124            btv->i2c_done, msecs_to_jiffies(85)) == -ERESTARTSYS)
 125                rc = -EIO;
 126
 127        if (btv->i2c_done & BT848_INT_RACK)
 128                rc = 1;
 129        btv->i2c_done = 0;
 130        return rc;
 131}
 132
 133#define I2C_HW (BT878_I2C_MODE  | BT848_I2C_SYNC |\
 134                BT848_I2C_SCL | BT848_I2C_SDA)
 135
 136static int
 137bttv_i2c_sendbytes(struct bttv *btv, const struct i2c_msg *msg, int last)
 138{
 139        u32 xmit;
 140        int retval,cnt;
 141
 142        /* sanity checks */
 143        if (0 == msg->len)
 144                return -EINVAL;
 145
 146        /* start, address + first byte */
 147        xmit = (msg->addr << 25) | (msg->buf[0] << 16) | I2C_HW;
 148        if (msg->len > 1 || !last)
 149                xmit |= BT878_I2C_NOSTOP;
 150        btwrite(xmit, BT848_I2C);
 151        retval = bttv_i2c_wait_done(btv);
 152        if (retval < 0)
 153                goto err;
 154        if (retval == 0)
 155                goto eio;
 156        if (i2c_debug) {
 157                pr_cont(" <W %02x %02x", msg->addr << 1, msg->buf[0]);
 158        }
 159
 160        for (cnt = 1; cnt < msg->len; cnt++ ) {
 161                /* following bytes */
 162                xmit = (msg->buf[cnt] << 24) | I2C_HW | BT878_I2C_NOSTART;
 163                if (cnt < msg->len-1 || !last)
 164                        xmit |= BT878_I2C_NOSTOP;
 165                btwrite(xmit, BT848_I2C);
 166                retval = bttv_i2c_wait_done(btv);
 167                if (retval < 0)
 168                        goto err;
 169                if (retval == 0)
 170                        goto eio;
 171                if (i2c_debug)
 172                        pr_cont(" %02x", msg->buf[cnt]);
 173        }
 174        if (i2c_debug && !(xmit & BT878_I2C_NOSTOP))
 175                pr_cont(">\n");
 176        return msg->len;
 177
 178 eio:
 179        retval = -EIO;
 180 err:
 181        if (i2c_debug)
 182                pr_cont(" ERR: %d\n",retval);
 183        return retval;
 184}
 185
 186static int
 187bttv_i2c_readbytes(struct bttv *btv, const struct i2c_msg *msg, int last)
 188{
 189        u32 xmit;
 190        u32 cnt;
 191        int retval;
 192
 193        for (cnt = 0; cnt < msg->len; cnt++) {
 194                xmit = (msg->addr << 25) | (1 << 24) | I2C_HW;
 195                if (cnt < msg->len-1)
 196                        xmit |= BT848_I2C_W3B;
 197                if (cnt < msg->len-1 || !last)
 198                        xmit |= BT878_I2C_NOSTOP;
 199                if (cnt)
 200                        xmit |= BT878_I2C_NOSTART;
 201
 202                if (i2c_debug) {
 203                        if (!(xmit & BT878_I2C_NOSTART))
 204                                pr_cont(" <R %02x", (msg->addr << 1) +1);
 205                }
 206
 207                btwrite(xmit, BT848_I2C);
 208                retval = bttv_i2c_wait_done(btv);
 209                if (retval < 0)
 210                        goto err;
 211                if (retval == 0)
 212                        goto eio;
 213                msg->buf[cnt] = ((u32)btread(BT848_I2C) >> 8) & 0xff;
 214                if (i2c_debug) {
 215                        pr_cont(" =%02x", msg->buf[cnt]);
 216                }
 217                if (i2c_debug && !(xmit & BT878_I2C_NOSTOP))
 218                        pr_cont(" >\n");
 219        }
 220
 221
 222        return msg->len;
 223
 224 eio:
 225        retval = -EIO;
 226 err:
 227        if (i2c_debug)
 228                pr_cont(" ERR: %d\n",retval);
 229        return retval;
 230}
 231
 232static int bttv_i2c_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num)
 233{
 234        struct v4l2_device *v4l2_dev = i2c_get_adapdata(i2c_adap);
 235        struct bttv *btv = to_bttv(v4l2_dev);
 236        int retval = 0;
 237        int i;
 238
 239        if (i2c_debug)
 240                pr_debug("bt-i2c:");
 241
 242        btwrite(BT848_INT_I2CDONE|BT848_INT_RACK, BT848_INT_STAT);
 243        for (i = 0 ; i < num; i++) {
 244                if (msgs[i].flags & I2C_M_RD) {
 245                        /* read */
 246                        retval = bttv_i2c_readbytes(btv, &msgs[i], i+1 == num);
 247                        if (retval < 0)
 248                                goto err;
 249                } else {
 250                        /* write */
 251                        retval = bttv_i2c_sendbytes(btv, &msgs[i], i+1 == num);
 252                        if (retval < 0)
 253                                goto err;
 254                }
 255        }
 256        return num;
 257
 258 err:
 259        return retval;
 260}
 261
 262static const struct i2c_algorithm bttv_algo = {
 263        .master_xfer   = bttv_i2c_xfer,
 264        .functionality = functionality,
 265};
 266
 267/* ----------------------------------------------------------------------- */
 268/* I2C functions - common stuff                                            */
 269
 270/* read I2C */
 271int bttv_I2CRead(struct bttv *btv, unsigned char addr, char *probe_for)
 272{
 273        unsigned char buffer = 0;
 274
 275        if (0 != btv->i2c_rc)
 276                return -1;
 277        if (bttv_verbose && NULL != probe_for)
 278                pr_info("%d: i2c: checking for %s @ 0x%02x... ",
 279                        btv->c.nr, probe_for, addr);
 280        btv->i2c_client.addr = addr >> 1;
 281        if (1 != i2c_master_recv(&btv->i2c_client, &buffer, 1)) {
 282                if (NULL != probe_for) {
 283                        if (bttv_verbose)
 284                                pr_cont("not found\n");
 285                } else
 286                        pr_warn("%d: i2c read 0x%x: error\n",
 287                                btv->c.nr, addr);
 288                return -1;
 289        }
 290        if (bttv_verbose && NULL != probe_for)
 291                pr_cont("found\n");
 292        return buffer;
 293}
 294
 295/* write I2C */
 296int bttv_I2CWrite(struct bttv *btv, unsigned char addr, unsigned char b1,
 297                    unsigned char b2, int both)
 298{
 299        unsigned char buffer[2];
 300        int bytes = both ? 2 : 1;
 301
 302        if (0 != btv->i2c_rc)
 303                return -1;
 304        btv->i2c_client.addr = addr >> 1;
 305        buffer[0] = b1;
 306        buffer[1] = b2;
 307        if (bytes != i2c_master_send(&btv->i2c_client, buffer, bytes))
 308                return -1;
 309        return 0;
 310}
 311
 312/* read EEPROM content */
 313void bttv_readee(struct bttv *btv, unsigned char *eedata, int addr)
 314{
 315        memset(eedata, 0, 256);
 316        if (0 != btv->i2c_rc)
 317                return;
 318        btv->i2c_client.addr = addr >> 1;
 319        tveeprom_read(&btv->i2c_client, eedata, 256);
 320}
 321
 322static char *i2c_devs[128] = {
 323        [ 0x1c >> 1 ] = "lgdt330x",
 324        [ 0x30 >> 1 ] = "IR (hauppauge)",
 325        [ 0x80 >> 1 ] = "msp34xx",
 326        [ 0x86 >> 1 ] = "tda9887",
 327        [ 0xa0 >> 1 ] = "eeprom",
 328        [ 0xc0 >> 1 ] = "tuner (analog)",
 329        [ 0xc2 >> 1 ] = "tuner (analog)",
 330};
 331
 332static void do_i2c_scan(char *name, struct i2c_client *c)
 333{
 334        unsigned char buf;
 335        int i,rc;
 336
 337        for (i = 0; i < ARRAY_SIZE(i2c_devs); i++) {
 338                c->addr = i;
 339                rc = i2c_master_recv(c,&buf,0);
 340                if (rc < 0)
 341                        continue;
 342                pr_info("%s: i2c scan: found device @ 0x%x  [%s]\n",
 343                        name, i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
 344        }
 345}
 346
 347/* init + register i2c adapter */
 348int init_bttv_i2c(struct bttv *btv)
 349{
 350        strlcpy(btv->i2c_client.name, "bttv internal", I2C_NAME_SIZE);
 351
 352        if (i2c_hw)
 353                btv->use_i2c_hw = 1;
 354        if (btv->use_i2c_hw) {
 355                /* bt878 */
 356                strlcpy(btv->c.i2c_adap.name, "bt878",
 357                        sizeof(btv->c.i2c_adap.name));
 358                btv->c.i2c_adap.algo = &bttv_algo;
 359        } else {
 360                /* bt848 */
 361        /* Prevents usage of invalid delay values */
 362                if (i2c_udelay<5)
 363                        i2c_udelay=5;
 364
 365                strlcpy(btv->c.i2c_adap.name, "bttv",
 366                        sizeof(btv->c.i2c_adap.name));
 367                btv->i2c_algo = bttv_i2c_algo_bit_template;
 368                btv->i2c_algo.udelay = i2c_udelay;
 369                btv->i2c_algo.data = btv;
 370                btv->c.i2c_adap.algo_data = &btv->i2c_algo;
 371        }
 372        btv->c.i2c_adap.owner = THIS_MODULE;
 373
 374        btv->c.i2c_adap.dev.parent = &btv->c.pci->dev;
 375        snprintf(btv->c.i2c_adap.name, sizeof(btv->c.i2c_adap.name),
 376                 "bt%d #%d [%s]", btv->id, btv->c.nr,
 377                 btv->use_i2c_hw ? "hw" : "sw");
 378
 379        i2c_set_adapdata(&btv->c.i2c_adap, &btv->c.v4l2_dev);
 380        btv->i2c_client.adapter = &btv->c.i2c_adap;
 381
 382
 383        if (btv->use_i2c_hw) {
 384                btv->i2c_rc = i2c_add_adapter(&btv->c.i2c_adap);
 385        } else {
 386                bttv_bit_setscl(btv,1);
 387                bttv_bit_setsda(btv,1);
 388                btv->i2c_rc = i2c_bit_add_bus(&btv->c.i2c_adap);
 389        }
 390        if (0 == btv->i2c_rc && i2c_scan)
 391                do_i2c_scan(btv->c.v4l2_dev.name, &btv->i2c_client);
 392
 393        return btv->i2c_rc;
 394}
 395
 396int fini_bttv_i2c(struct bttv *btv)
 397{
 398        if (btv->i2c_rc == 0)
 399                i2c_del_adapter(&btv->c.i2c_adap);
 400
 401        return 0;
 402}
 403