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, "
  48                        "instead of software bitbang");
  49module_param(i2c_scan,  int, 0444);
  50MODULE_PARM_DESC(i2c_scan,"scan i2c bus at insmod time");
  51
  52static unsigned int i2c_udelay = 5;
  53module_param(i2c_udelay, int, 0444);
  54MODULE_PARM_DESC(i2c_udelay,"soft i2c delay at insmod time, in usecs "
  55                "(should be 5 or higher). Lower value means higher bus speed.");
  56
  57/* ----------------------------------------------------------------------- */
  58/* I2C functions - bitbanging adapter (software i2c)                       */
  59
  60static void bttv_bit_setscl(void *data, int state)
  61{
  62        struct bttv *btv = (struct bttv*)data;
  63
  64        if (state)
  65                btv->i2c_state |= 0x02;
  66        else
  67                btv->i2c_state &= ~0x02;
  68        btwrite(btv->i2c_state, BT848_I2C);
  69        btread(BT848_I2C);
  70}
  71
  72static void bttv_bit_setsda(void *data, int state)
  73{
  74        struct bttv *btv = (struct bttv*)data;
  75
  76        if (state)
  77                btv->i2c_state |= 0x01;
  78        else
  79                btv->i2c_state &= ~0x01;
  80        btwrite(btv->i2c_state, BT848_I2C);
  81        btread(BT848_I2C);
  82}
  83
  84static int bttv_bit_getscl(void *data)
  85{
  86        struct bttv *btv = (struct bttv*)data;
  87        int state;
  88
  89        state = btread(BT848_I2C) & 0x02 ? 1 : 0;
  90        return state;
  91}
  92
  93static int bttv_bit_getsda(void *data)
  94{
  95        struct bttv *btv = (struct bttv*)data;
  96        int state;
  97
  98        state = btread(BT848_I2C) & 0x01;
  99        return state;
 100}
 101
 102static struct i2c_algo_bit_data bttv_i2c_algo_bit_template = {
 103        .setsda  = bttv_bit_setsda,
 104        .setscl  = bttv_bit_setscl,
 105        .getsda  = bttv_bit_getsda,
 106        .getscl  = bttv_bit_getscl,
 107        .udelay  = 16,
 108        .timeout = 200,
 109};
 110
 111/* ----------------------------------------------------------------------- */
 112/* I2C functions - hardware i2c                                            */
 113
 114static u32 functionality(struct i2c_adapter *adap)
 115{
 116        return I2C_FUNC_SMBUS_EMUL;
 117}
 118
 119static int
 120bttv_i2c_wait_done(struct bttv *btv)
 121{
 122        int rc = 0;
 123
 124        /* timeout */
 125        if (wait_event_interruptible_timeout(btv->i2c_queue,
 126            btv->i2c_done, msecs_to_jiffies(85)) == -ERESTARTSYS)
 127                rc = -EIO;
 128
 129        if (btv->i2c_done & BT848_INT_RACK)
 130                rc = 1;
 131        btv->i2c_done = 0;
 132        return rc;
 133}
 134
 135#define I2C_HW (BT878_I2C_MODE  | BT848_I2C_SYNC |\
 136                BT848_I2C_SCL | BT848_I2C_SDA)
 137
 138static int
 139bttv_i2c_sendbytes(struct bttv *btv, const struct i2c_msg *msg, int last)
 140{
 141        u32 xmit;
 142        int retval,cnt;
 143
 144        /* sanity checks */
 145        if (0 == msg->len)
 146                return -EINVAL;
 147
 148        /* start, address + first byte */
 149        xmit = (msg->addr << 25) | (msg->buf[0] << 16) | I2C_HW;
 150        if (msg->len > 1 || !last)
 151                xmit |= BT878_I2C_NOSTOP;
 152        btwrite(xmit, BT848_I2C);
 153        retval = bttv_i2c_wait_done(btv);
 154        if (retval < 0)
 155                goto err;
 156        if (retval == 0)
 157                goto eio;
 158        if (i2c_debug) {
 159                pr_cont(" <W %02x %02x", msg->addr << 1, msg->buf[0]);
 160        }
 161
 162        for (cnt = 1; cnt < msg->len; cnt++ ) {
 163                /* following bytes */
 164                xmit = (msg->buf[cnt] << 24) | I2C_HW | BT878_I2C_NOSTART;
 165                if (cnt < msg->len-1 || !last)
 166                        xmit |= BT878_I2C_NOSTOP;
 167                btwrite(xmit, BT848_I2C);
 168                retval = bttv_i2c_wait_done(btv);
 169                if (retval < 0)
 170                        goto err;
 171                if (retval == 0)
 172                        goto eio;
 173                if (i2c_debug)
 174                        pr_cont(" %02x", msg->buf[cnt]);
 175        }
 176        if (i2c_debug && !(xmit & BT878_I2C_NOSTOP))
 177                pr_cont(">\n");
 178        return msg->len;
 179
 180 eio:
 181        retval = -EIO;
 182 err:
 183        if (i2c_debug)
 184                pr_cont(" ERR: %d\n",retval);
 185        return retval;
 186}
 187
 188static int
 189bttv_i2c_readbytes(struct bttv *btv, const struct i2c_msg *msg, int last)
 190{
 191        u32 xmit;
 192        u32 cnt;
 193        int retval;
 194
 195        for (cnt = 0; cnt < msg->len; cnt++) {
 196                xmit = (msg->addr << 25) | (1 << 24) | I2C_HW;
 197                if (cnt < msg->len-1)
 198                        xmit |= BT848_I2C_W3B;
 199                if (cnt < msg->len-1 || !last)
 200                        xmit |= BT878_I2C_NOSTOP;
 201                if (cnt)
 202                        xmit |= BT878_I2C_NOSTART;
 203
 204                if (i2c_debug) {
 205                        if (!(xmit & BT878_I2C_NOSTART))
 206                                pr_cont(" <R %02x", (msg->addr << 1) +1);
 207                }
 208
 209                btwrite(xmit, BT848_I2C);
 210                retval = bttv_i2c_wait_done(btv);
 211                if (retval < 0)
 212                        goto err;
 213                if (retval == 0)
 214                        goto eio;
 215                msg->buf[cnt] = ((u32)btread(BT848_I2C) >> 8) & 0xff;
 216                if (i2c_debug) {
 217                        pr_cont(" =%02x", msg->buf[cnt]);
 218                }
 219                if (i2c_debug && !(xmit & BT878_I2C_NOSTOP))
 220                        pr_cont(" >\n");
 221        }
 222
 223
 224        return msg->len;
 225
 226 eio:
 227        retval = -EIO;
 228 err:
 229        if (i2c_debug)
 230                pr_cont(" ERR: %d\n",retval);
 231        return retval;
 232}
 233
 234static int bttv_i2c_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num)
 235{
 236        struct v4l2_device *v4l2_dev = i2c_get_adapdata(i2c_adap);
 237        struct bttv *btv = to_bttv(v4l2_dev);
 238        int retval = 0;
 239        int i;
 240
 241        if (i2c_debug)
 242                pr_debug("bt-i2c:");
 243
 244        btwrite(BT848_INT_I2CDONE|BT848_INT_RACK, BT848_INT_STAT);
 245        for (i = 0 ; i < num; i++) {
 246                if (msgs[i].flags & I2C_M_RD) {
 247                        /* read */
 248                        retval = bttv_i2c_readbytes(btv, &msgs[i], i+1 == num);
 249                        if (retval < 0)
 250                                goto err;
 251                } else {
 252                        /* write */
 253                        retval = bttv_i2c_sendbytes(btv, &msgs[i], i+1 == num);
 254                        if (retval < 0)
 255                                goto err;
 256                }
 257        }
 258        return num;
 259
 260 err:
 261        return retval;
 262}
 263
 264static const struct i2c_algorithm bttv_algo = {
 265        .master_xfer   = bttv_i2c_xfer,
 266        .functionality = functionality,
 267};
 268
 269/* ----------------------------------------------------------------------- */
 270/* I2C functions - common stuff                                            */
 271
 272/* read I2C */
 273int bttv_I2CRead(struct bttv *btv, unsigned char addr, char *probe_for)
 274{
 275        unsigned char buffer = 0;
 276
 277        if (0 != btv->i2c_rc)
 278                return -1;
 279        if (bttv_verbose && NULL != probe_for)
 280                pr_info("%d: i2c: checking for %s @ 0x%02x... ",
 281                        btv->c.nr, probe_for, addr);
 282        btv->i2c_client.addr = addr >> 1;
 283        if (1 != i2c_master_recv(&btv->i2c_client, &buffer, 1)) {
 284                if (NULL != probe_for) {
 285                        if (bttv_verbose)
 286                                pr_cont("not found\n");
 287                } else
 288                        pr_warn("%d: i2c read 0x%x: error\n",
 289                                btv->c.nr, addr);
 290                return -1;
 291        }
 292        if (bttv_verbose && NULL != probe_for)
 293                pr_cont("found\n");
 294        return buffer;
 295}
 296
 297/* write I2C */
 298int bttv_I2CWrite(struct bttv *btv, unsigned char addr, unsigned char b1,
 299                    unsigned char b2, int both)
 300{
 301        unsigned char buffer[2];
 302        int bytes = both ? 2 : 1;
 303
 304        if (0 != btv->i2c_rc)
 305                return -1;
 306        btv->i2c_client.addr = addr >> 1;
 307        buffer[0] = b1;
 308        buffer[1] = b2;
 309        if (bytes != i2c_master_send(&btv->i2c_client, buffer, bytes))
 310                return -1;
 311        return 0;
 312}
 313
 314/* read EEPROM content */
 315void bttv_readee(struct bttv *btv, unsigned char *eedata, int addr)
 316{
 317        memset(eedata, 0, 256);
 318        if (0 != btv->i2c_rc)
 319                return;
 320        btv->i2c_client.addr = addr >> 1;
 321        tveeprom_read(&btv->i2c_client, eedata, 256);
 322}
 323
 324static char *i2c_devs[128] = {
 325        [ 0x1c >> 1 ] = "lgdt330x",
 326        [ 0x30 >> 1 ] = "IR (hauppauge)",
 327        [ 0x80 >> 1 ] = "msp34xx",
 328        [ 0x86 >> 1 ] = "tda9887",
 329        [ 0xa0 >> 1 ] = "eeprom",
 330        [ 0xc0 >> 1 ] = "tuner (analog)",
 331        [ 0xc2 >> 1 ] = "tuner (analog)",
 332};
 333
 334static void do_i2c_scan(char *name, struct i2c_client *c)
 335{
 336        unsigned char buf;
 337        int i,rc;
 338
 339        for (i = 0; i < ARRAY_SIZE(i2c_devs); i++) {
 340                c->addr = i;
 341                rc = i2c_master_recv(c,&buf,0);
 342                if (rc < 0)
 343                        continue;
 344                pr_info("%s: i2c scan: found device @ 0x%x  [%s]\n",
 345                        name, i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
 346        }
 347}
 348
 349/* init + register i2c adapter */
 350int init_bttv_i2c(struct bttv *btv)
 351{
 352        strlcpy(btv->i2c_client.name, "bttv internal", I2C_NAME_SIZE);
 353
 354        if (i2c_hw)
 355                btv->use_i2c_hw = 1;
 356        if (btv->use_i2c_hw) {
 357                /* bt878 */
 358                strlcpy(btv->c.i2c_adap.name, "bt878",
 359                        sizeof(btv->c.i2c_adap.name));
 360                btv->c.i2c_adap.algo = &bttv_algo;
 361        } else {
 362                /* bt848 */
 363        /* Prevents usage of invalid delay values */
 364                if (i2c_udelay<5)
 365                        i2c_udelay=5;
 366
 367                strlcpy(btv->c.i2c_adap.name, "bttv",
 368                        sizeof(btv->c.i2c_adap.name));
 369                btv->i2c_algo = bttv_i2c_algo_bit_template;
 370                btv->i2c_algo.udelay = i2c_udelay;
 371                btv->i2c_algo.data = btv;
 372                btv->c.i2c_adap.algo_data = &btv->i2c_algo;
 373        }
 374        btv->c.i2c_adap.owner = THIS_MODULE;
 375
 376        btv->c.i2c_adap.dev.parent = &btv->c.pci->dev;
 377        snprintf(btv->c.i2c_adap.name, sizeof(btv->c.i2c_adap.name),
 378                 "bt%d #%d [%s]", btv->id, btv->c.nr,
 379                 btv->use_i2c_hw ? "hw" : "sw");
 380
 381        i2c_set_adapdata(&btv->c.i2c_adap, &btv->c.v4l2_dev);
 382        btv->i2c_client.adapter = &btv->c.i2c_adap;
 383
 384
 385        if (btv->use_i2c_hw) {
 386                btv->i2c_rc = i2c_add_adapter(&btv->c.i2c_adap);
 387        } else {
 388                bttv_bit_setscl(btv,1);
 389                bttv_bit_setsda(btv,1);
 390                btv->i2c_rc = i2c_bit_add_bus(&btv->c.i2c_adap);
 391        }
 392        if (0 == btv->i2c_rc && i2c_scan)
 393                do_i2c_scan(btv->c.v4l2_dev.name, &btv->i2c_client);
 394
 395        return btv->i2c_rc;
 396}
 397
 398int fini_bttv_i2c(struct bttv *btv)
 399{
 400        if (btv->i2c_rc == 0)
 401                i2c_del_adapter(&btv->c.i2c_adap);
 402
 403        return 0;
 404}
 405