LXR linux/drivers/media/usb/au0828/au0828-i2c.c

   1/*
   2 *  Driver for the Auvitek AU0828 USB bridge
   3 *
   4 *  Copyright (c) 2008 Steven Toth <stoth@linuxtv.org>
   5 *
   6 *  This program is free software; you can redistribute it and/or modify
   7 *  it under the terms of the GNU General Public License as published by
   8 *  the Free Software Foundation; either version 2 of the License, or
   9 *  (at your option) any later version.
  10 *
  11 *  This program is distributed in the hope that it will be useful,
  12 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 *
  15 *  GNU General Public License for more details.
  16 *
  17 *  You should have received a copy of the GNU General Public License
  18 *  along with this program; if not, write to the Free Software
  19 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20 */
  21
  22#include "au0828.h"
  23
  24#include <linux/module.h>
  25#include <linux/moduleparam.h>
  26#include <linux/init.h>
  27#include <linux/delay.h>
  28#include <linux/io.h>
  29
  30#include "media/tuner.h"
  31#include <media/v4l2-common.h>
  32
  33static int i2c_scan;
  34module_param(i2c_scan, int, 0444);
  35MODULE_PARM_DESC(i2c_scan, "scan i2c bus at insmod time");
  36
  37#define I2C_WAIT_DELAY 25
  38#define I2C_WAIT_RETRY 1000
  39
  40static inline int i2c_slave_did_write_ack(struct i2c_adapter *i2c_adap)
  41{
  42        struct au0828_dev *dev = i2c_adap->algo_data;
  43        return au0828_read(dev, AU0828_I2C_STATUS_201) &
  44                AU0828_I2C_STATUS_NO_WRITE_ACK ? 0 : 1;
  45}
  46
  47static inline int i2c_slave_did_read_ack(struct i2c_adapter *i2c_adap)
  48{
  49        struct au0828_dev *dev = i2c_adap->algo_data;
  50        return au0828_read(dev, AU0828_I2C_STATUS_201) &
  51                AU0828_I2C_STATUS_NO_READ_ACK ? 0 : 1;
  52}
  53
  54static int i2c_wait_read_ack(struct i2c_adapter *i2c_adap)
  55{
  56        int count;
  57
  58        for (count = 0; count < I2C_WAIT_RETRY; count++) {
  59                if (!i2c_slave_did_read_ack(i2c_adap))
  60                        break;
  61                udelay(I2C_WAIT_DELAY);
  62        }
  63
  64        if (I2C_WAIT_RETRY == count)
  65                return 0;
  66
  67        return 1;
  68}
  69
  70static inline int i2c_is_read_busy(struct i2c_adapter *i2c_adap)
  71{
  72        struct au0828_dev *dev = i2c_adap->algo_data;
  73        return au0828_read(dev, AU0828_I2C_STATUS_201) &
  74                AU0828_I2C_STATUS_READ_DONE ? 0 : 1;
  75}
  76
  77static int i2c_wait_read_done(struct i2c_adapter *i2c_adap)
  78{
  79        int count;
  80
  81        for (count = 0; count < I2C_WAIT_RETRY; count++) {
  82                if (!i2c_is_read_busy(i2c_adap))
  83                        break;
  84                udelay(I2C_WAIT_DELAY);
  85        }
  86
  87        if (I2C_WAIT_RETRY == count)
  88                return 0;
  89
  90        return 1;
  91}
  92
  93static inline int i2c_is_write_done(struct i2c_adapter *i2c_adap)
  94{
  95        struct au0828_dev *dev = i2c_adap->algo_data;
  96        return au0828_read(dev, AU0828_I2C_STATUS_201) &
  97                AU0828_I2C_STATUS_WRITE_DONE ? 1 : 0;
  98}
  99
 100static int i2c_wait_write_done(struct i2c_adapter *i2c_adap)
 101{
 102        int count;
 103
 104        for (count = 0; count < I2C_WAIT_RETRY; count++) {
 105                if (i2c_is_write_done(i2c_adap))
 106                        break;
 107                udelay(I2C_WAIT_DELAY);
 108        }
 109
 110        if (I2C_WAIT_RETRY == count)
 111                return 0;
 112
 113        return 1;
 114}
 115
 116static inline int i2c_is_busy(struct i2c_adapter *i2c_adap)
 117{
 118        struct au0828_dev *dev = i2c_adap->algo_data;
 119        return au0828_read(dev, AU0828_I2C_STATUS_201) &
 120                AU0828_I2C_STATUS_BUSY ? 1 : 0;
 121}
 122
 123static int i2c_wait_done(struct i2c_adapter *i2c_adap)
 124{
 125        int count;
 126
 127        for (count = 0; count < I2C_WAIT_RETRY; count++) {
 128                if (!i2c_is_busy(i2c_adap))
 129                        break;
 130                udelay(I2C_WAIT_DELAY);
 131        }
 132
 133        if (I2C_WAIT_RETRY == count)
 134                return 0;
 135
 136        return 1;
 137}
 138
 139/* FIXME: Implement join handling correctly */
 140static int i2c_sendbytes(struct i2c_adapter *i2c_adap,
 141        const struct i2c_msg *msg, int joined_rlen)
 142{
 143        int i, strobe = 0;
 144        struct au0828_dev *dev = i2c_adap->algo_data;
 145        u8 i2c_speed = dev->board.i2c_clk_divider;
 146
 147        dprintk(4, "%s()\n", __func__);
 148
 149        au0828_write(dev, AU0828_I2C_MULTIBYTE_MODE_2FF, 0x01);
 150
 151        if (((dev->board.tuner_type == TUNER_XC5000) ||
 152             (dev->board.tuner_type == TUNER_XC5000C)) &&
 153            (dev->board.tuner_addr == msg->addr)) {
 154                /*
 155                 * Due to I2C clock stretch, we need to use a lower speed
 156                 * on xc5000 for commands. However, firmware transfer can
 157                 * speed up to 400 KHz.
 158                 */
 159                if (msg->len == 64)
 160                        i2c_speed = AU0828_I2C_CLK_250KHZ;
 161                else
 162                        i2c_speed = AU0828_I2C_CLK_20KHZ;
 163        }
 164        /* Set the I2C clock */
 165        au0828_write(dev, AU0828_I2C_CLK_DIVIDER_202, i2c_speed);
 166
 167        /* Hardware needs 8 bit addresses */
 168        au0828_write(dev, AU0828_I2C_DEST_ADDR_203, msg->addr << 1);
 169
 170        dprintk(4, "SEND: %02x\n", msg->addr);
 171
 172        /* Deal with i2c_scan */
 173        if (msg->len == 0) {
 174                /* The analog tuner detection code makes use of the SMBUS_QUICK
 175                   message (which involves a zero length i2c write).  To avoid
 176                   checking the status register when we didn't strobe out any
 177                   actual bytes to the bus, just do a read check.  This is
 178                   consistent with how I saw i2c device checking done in the
 179                   USB trace of the Windows driver */
 180                au0828_write(dev, AU0828_I2C_TRIGGER_200,
 181                             AU0828_I2C_TRIGGER_READ);
 182
 183                if (!i2c_wait_done(i2c_adap))
 184                        return -EIO;
 185
 186                if (i2c_wait_read_ack(i2c_adap))
 187                        return -EIO;
 188
 189                return 0;
 190        }
 191
 192        for (i = 0; i < msg->len;) {
 193
 194                dprintk(4, " %02x\n", msg->buf[i]);
 195
 196                au0828_write(dev, AU0828_I2C_WRITE_FIFO_205, msg->buf[i]);
 197
 198                strobe++;
 199                i++;
 200
 201                if ((strobe >= 4) || (i >= msg->len)) {
 202
 203                        /* Strobe the byte into the bus */
 204                        if (i < msg->len)
 205                                au0828_write(dev, AU0828_I2C_TRIGGER_200,
 206                                             AU0828_I2C_TRIGGER_WRITE |
 207                                             AU0828_I2C_TRIGGER_HOLD);
 208                        else
 209                                au0828_write(dev, AU0828_I2C_TRIGGER_200,
 210                                             AU0828_I2C_TRIGGER_WRITE);
 211
 212                        /* Reset strobe trigger */
 213                        strobe = 0;
 214
 215                        if (!i2c_wait_write_done(i2c_adap))
 216                                return -EIO;
 217
 218                }
 219
 220        }
 221        if (!i2c_wait_done(i2c_adap))
 222                return -EIO;
 223
 224        dprintk(4, "\n");
 225
 226        return msg->len;
 227}
 228
 229/* FIXME: Implement join handling correctly */
 230static int i2c_readbytes(struct i2c_adapter *i2c_adap,
 231        const struct i2c_msg *msg, int joined)
 232{
 233        struct au0828_dev *dev = i2c_adap->algo_data;
 234        u8 i2c_speed = dev->board.i2c_clk_divider;
 235        int i;
 236
 237        dprintk(4, "%s()\n", __func__);
 238
 239        au0828_write(dev, AU0828_I2C_MULTIBYTE_MODE_2FF, 0x01);
 240
 241        /*
 242         * Due to xc5000c clock stretch, we cannot use full speed at
 243         * readings from xc5000, as otherwise they'll fail.
 244         */
 245        if (((dev->board.tuner_type == TUNER_XC5000) ||
 246             (dev->board.tuner_type == TUNER_XC5000C)) &&
 247            (dev->board.tuner_addr == msg->addr))
 248                i2c_speed = AU0828_I2C_CLK_20KHZ;
 249
 250        /* Set the I2C clock */
 251        au0828_write(dev, AU0828_I2C_CLK_DIVIDER_202, i2c_speed);
 252
 253        /* Hardware needs 8 bit addresses */
 254        au0828_write(dev, AU0828_I2C_DEST_ADDR_203, msg->addr << 1);
 255
 256        dprintk(4, " RECV:\n");
 257
 258        /* Deal with i2c_scan */
 259        if (msg->len == 0) {
 260                au0828_write(dev, AU0828_I2C_TRIGGER_200,
 261                             AU0828_I2C_TRIGGER_READ);
 262
 263                if (i2c_wait_read_ack(i2c_adap))
 264                        return -EIO;
 265                return 0;
 266        }
 267
 268        for (i = 0; i < msg->len;) {
 269
 270                i++;
 271
 272                if (i < msg->len)
 273                        au0828_write(dev, AU0828_I2C_TRIGGER_200,
 274                                     AU0828_I2C_TRIGGER_READ |
 275                                     AU0828_I2C_TRIGGER_HOLD);
 276                else
 277                        au0828_write(dev, AU0828_I2C_TRIGGER_200,
 278                                     AU0828_I2C_TRIGGER_READ);
 279
 280                if (!i2c_wait_read_done(i2c_adap))
 281                        return -EIO;
 282
 283                msg->buf[i-1] = au0828_read(dev, AU0828_I2C_READ_FIFO_209) &
 284                        0xff;
 285
 286                dprintk(4, " %02x\n", msg->buf[i-1]);
 287        }
 288        if (!i2c_wait_done(i2c_adap))
 289                return -EIO;
 290
 291        dprintk(4, "\n");
 292
 293        return msg->len;
 294}
 295
 296static int i2c_xfer(struct i2c_adapter *i2c_adap,
 297                    struct i2c_msg *msgs, int num)
 298{
 299        int i, retval = 0;
 300
 301        dprintk(4, "%s(num = %d)\n", __func__, num);
 302
 303        for (i = 0; i < num; i++) {
 304                dprintk(4, "%s(num = %d) addr = 0x%02x  len = 0x%x\n",
 305                        __func__, num, msgs[i].addr, msgs[i].len);
 306                if (msgs[i].flags & I2C_M_RD) {
 307                        /* read */
 308                        retval = i2c_readbytes(i2c_adap, &msgs[i], 0);
 309                } else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) &&
 310                           msgs[i].addr == msgs[i + 1].addr) {
 311                        /* write then read from same address */
 312                        retval = i2c_sendbytes(i2c_adap, &msgs[i],
 313                                               msgs[i + 1].len);
 314                        if (retval < 0)
 315                                goto err;
 316                        i++;
 317                        retval = i2c_readbytes(i2c_adap, &msgs[i], 1);
 318                } else {
 319                        /* write */
 320                        retval = i2c_sendbytes(i2c_adap, &msgs[i], 0);
 321                }
 322                if (retval < 0)
 323                        goto err;
 324        }
 325        return num;
 326
 327err:
 328        return retval;
 329}
 330
 331static u32 au0828_functionality(struct i2c_adapter *adap)
 332{
 333        return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C;
 334}
 335
 336static struct i2c_algorithm au0828_i2c_algo_template = {
 337        .master_xfer    = i2c_xfer,
 338        .functionality  = au0828_functionality,
 339};
 340
 341/* ----------------------------------------------------------------------- */
 342
 343static struct i2c_adapter au0828_i2c_adap_template = {
 344        .name              = KBUILD_MODNAME,
 345        .owner             = THIS_MODULE,
 346        .algo              = &au0828_i2c_algo_template,
 347};
 348
 349static struct i2c_client au0828_i2c_client_template = {
 350        .name   = "au0828 internal",
 351};
 352
 353static char *i2c_devs[128] = {
 354        [0x8e >> 1] = "au8522",
 355        [0xa0 >> 1] = "eeprom",
 356        [0xc2 >> 1] = "tuner/xc5000",
 357};
 358
 359static void do_i2c_scan(char *name, struct i2c_client *c)
 360{
 361        unsigned char buf;
 362        int i, rc;
 363
 364        for (i = 0; i < 128; i++) {
 365                c->addr = i;
 366                rc = i2c_master_recv(c, &buf, 0);
 367                if (rc < 0)
 368                        continue;
 369                pr_info("%s: i2c scan: found device @ 0x%x  [%s]\n",
 370                       name, i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
 371        }
 372}
 373
 374/* init + register i2c adapter */
 375int au0828_i2c_register(struct au0828_dev *dev)
 376{
 377        dprintk(1, "%s()\n", __func__);
 378
 379        dev->i2c_adap = au0828_i2c_adap_template;
 380        dev->i2c_algo = au0828_i2c_algo_template;
 381        dev->i2c_client = au0828_i2c_client_template;
 382
 383        dev->i2c_adap.dev.parent = &dev->usbdev->dev;
 384
 385        strlcpy(dev->i2c_adap.name, KBUILD_MODNAME,
 386                sizeof(dev->i2c_adap.name));
 387
 388        dev->i2c_adap.algo = &dev->i2c_algo;
 389        dev->i2c_adap.algo_data = dev;
 390#ifdef CONFIG_VIDEO_AU0828_V4L2
 391        i2c_set_adapdata(&dev->i2c_adap, &dev->v4l2_dev);
 392#else
 393        i2c_set_adapdata(&dev->i2c_adap, dev);
 394#endif
 395        i2c_add_adapter(&dev->i2c_adap);
 396
 397        dev->i2c_client.adapter = &dev->i2c_adap;
 398
 399        if (0 == dev->i2c_rc) {
 400                pr_info("i2c bus registered\n");
 401                if (i2c_scan)
 402                        do_i2c_scan(KBUILD_MODNAME, &dev->i2c_client);
 403        } else
 404                pr_info("i2c bus register FAILED\n");
 405
 406        return dev->i2c_rc;
 407}
 408
 409int au0828_i2c_unregister(struct au0828_dev *dev)
 410{
 411        i2c_del_adapter(&dev->i2c_adap);
 412        return 0;
 413}
 414
 415