linux/drivers/media/video/tda9840.c
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   1 /*
   2    tda9840 - i2c-driver for the tda9840 by SGS Thomson
   3
   4    Copyright (C) 1998-2003 Michael Hunold <michael@mihu.de>
   5
   6    The tda9840 is a stereo/dual sound processor with digital
   7    identification. It can be found at address 0x84 on the i2c-bus.
   8
   9    For detailed informations download the specifications directly
  10    from SGS Thomson at http://www.st.com
  11
  12    This program is free software; you can redistribute it and/or modify
  13    it under the terms of the GNU General Public License as published by
  14    the Free Software Foundation; either version 2 of the License, or
  15    (at your option) any later version.
  16
  17    This program is distributed in the hope that it will be useful,
  18    but WITHOUT ANY WARRANTY; without even the implied warranty of
  19    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20    GNU General Public License for more details.
  21
  22    You should have received a copy of the GNU General Public License
  23    along with this program; if not, write to the Free Software
  24    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  25  */
  26
  27
  28#include <linux/module.h>
  29#include <linux/ioctl.h>
  30#include <linux/i2c.h>
  31
  32#include "tda9840.h"
  33
  34static int debug = 0;           /* insmod parameter */
  35module_param(debug, int, 0644);
  36MODULE_PARM_DESC(debug, "Turn on/off device debugging (default:off).");
  37#define dprintk(args...) \
  38            do { if (debug) { printk("%s: %s()[%d]: ", KBUILD_MODNAME, __FUNCTION__, __LINE__); printk(args); } } while (0)
  39
  40#define SWITCH          0x00
  41#define LEVEL_ADJUST    0x02
  42#define STEREO_ADJUST   0x03
  43#define TEST            0x04
  44
  45/* addresses to scan, found only at 0x42 (7-Bit) */
  46static unsigned short normal_i2c[] = { I2C_ADDR_TDA9840, I2C_CLIENT_END };
  47
  48/* magic definition of all other variables and things */
  49I2C_CLIENT_INSMOD;
  50
  51static struct i2c_driver driver;
  52static struct i2c_client client_template;
  53
  54static int command(struct i2c_client *client, unsigned int cmd, void *arg)
  55{
  56        int result;
  57        int byte = *(int *)arg;
  58
  59        switch (cmd) {
  60        case TDA9840_SWITCH:
  61
  62                dprintk("TDA9840_SWITCH: 0x%02x\n", byte);
  63
  64                if (byte != TDA9840_SET_MONO
  65                    && byte != TDA9840_SET_MUTE
  66                    && byte != TDA9840_SET_STEREO
  67                    && byte != TDA9840_SET_LANG1
  68                    && byte != TDA9840_SET_LANG2
  69                    && byte != TDA9840_SET_BOTH
  70                    && byte != TDA9840_SET_BOTH_R
  71                    && byte != TDA9840_SET_EXTERNAL) {
  72                        return -EINVAL;
  73                }
  74
  75                result = i2c_smbus_write_byte_data(client, SWITCH, byte);
  76                if (result)
  77                        dprintk("i2c_smbus_write_byte() failed, ret:%d\n", result);
  78                break;
  79
  80        case TDA9840_LEVEL_ADJUST:
  81
  82                dprintk("TDA9840_LEVEL_ADJUST: %d\n", byte);
  83
  84                /* check for correct range */
  85                if (byte > 25 || byte < -20)
  86                        return -EINVAL;
  87
  88                /* calculate actual value to set, see specs, page 18 */
  89                byte /= 5;
  90                if (0 < byte)
  91                        byte += 0x8;
  92                else
  93                        byte = -byte;
  94
  95                result = i2c_smbus_write_byte_data(client, LEVEL_ADJUST, byte);
  96                if (result)
  97                        dprintk("i2c_smbus_write_byte() failed, ret:%d\n", result);
  98                break;
  99
 100        case TDA9840_STEREO_ADJUST:
 101
 102                dprintk("TDA9840_STEREO_ADJUST: %d\n", byte);
 103
 104                /* check for correct range */
 105                if (byte > 25 || byte < -24)
 106                        return -EINVAL;
 107
 108                /* calculate actual value to set */
 109                byte /= 5;
 110                if (0 < byte)
 111                        byte += 0x20;
 112                else
 113                        byte = -byte;
 114
 115                result = i2c_smbus_write_byte_data(client, STEREO_ADJUST, byte);
 116                if (result)
 117                        dprintk("i2c_smbus_write_byte() failed, ret:%d\n", result);
 118                break;
 119
 120        case TDA9840_DETECT: {
 121                int *ret = (int *)arg;
 122
 123                byte = i2c_smbus_read_byte_data(client, STEREO_ADJUST);
 124                if (byte == -1) {
 125                        dprintk("i2c_smbus_read_byte_data() failed\n");
 126                        return -EIO;
 127                }
 128
 129                if (0 != (byte & 0x80)) {
 130                        dprintk("TDA9840_DETECT: register contents invalid\n");
 131                        return -EINVAL;
 132                }
 133
 134                dprintk("TDA9840_DETECT: byte: 0x%02x\n", byte);
 135                *ret = ((byte & 0x60) >> 5);
 136                result = 0;
 137                break;
 138        }
 139        case TDA9840_TEST:
 140                dprintk("TDA9840_TEST: 0x%02x\n", byte);
 141
 142                /* mask out irrelevant bits */
 143                byte &= 0x3;
 144
 145                result = i2c_smbus_write_byte_data(client, TEST, byte);
 146                if (result)
 147                        dprintk("i2c_smbus_write_byte() failed, ret:%d\n", result);
 148                break;
 149        default:
 150                return -ENOIOCTLCMD;
 151        }
 152
 153        if (result)
 154                return -EIO;
 155
 156        return 0;
 157}
 158
 159static int detect(struct i2c_adapter *adapter, int address, int kind)
 160{
 161        struct i2c_client *client;
 162        int result = 0;
 163
 164        int byte = 0x0;
 165
 166        /* let's see whether this adapter can support what we need */
 167        if (0 == i2c_check_functionality(adapter,
 168                                    I2C_FUNC_SMBUS_READ_BYTE_DATA |
 169                                    I2C_FUNC_SMBUS_WRITE_BYTE_DATA)) {
 170                return 0;
 171        }
 172
 173        /* allocate memory for client structure */
 174        client = kmalloc(sizeof(struct i2c_client), GFP_KERNEL);
 175        if (0 == client) {
 176                printk("not enough kernel memory\n");
 177                return -ENOMEM;
 178        }
 179
 180        /* fill client structure */
 181        memcpy(client, &client_template, sizeof(struct i2c_client));
 182        client->addr = address;
 183        client->adapter = adapter;
 184
 185        /* tell the i2c layer a new client has arrived */
 186        if (0 != (result = i2c_attach_client(client))) {
 187                kfree(client);
 188                return result;
 189        }
 190
 191        /* set initial values for level & stereo - adjustment, mode */
 192        byte = 0;
 193        result  = command(client, TDA9840_LEVEL_ADJUST, &byte);
 194        result += command(client, TDA9840_STEREO_ADJUST, &byte);
 195        byte = TDA9840_SET_MONO;
 196        result = command(client, TDA9840_SWITCH, &byte);
 197        if (result) {
 198                dprintk("could not initialize tda9840\n");
 199                return -ENODEV;
 200        }
 201
 202        printk("tda9840: detected @ 0x%02x on adapter %s\n", address, &client->adapter->name[0]);
 203        return 0;
 204}
 205
 206static int attach(struct i2c_adapter *adapter)
 207{
 208        /* let's see whether this is a know adapter we can attach to */
 209        if (adapter->id != I2C_HW_SAA7146) {
 210                dprintk("refusing to probe on unknown adapter [name='%s',id=0x%x]\n", adapter->name, adapter->id);
 211                return -ENODEV;
 212        }
 213
 214        return i2c_probe(adapter, &addr_data, &detect);
 215}
 216
 217static int detach(struct i2c_client *client)
 218{
 219        int ret = i2c_detach_client(client);
 220        kfree(client);
 221        return ret;
 222}
 223
 224static struct i2c_driver driver = {
 225        .driver = {
 226                .name = "tda9840",
 227        },
 228        .id     = I2C_DRIVERID_TDA9840,
 229        .attach_adapter = attach,
 230        .detach_client  = detach,
 231        .command        = command,
 232};
 233
 234static struct i2c_client client_template = {
 235        .name = "tda9840",
 236        .driver = &driver,
 237};
 238
 239static int __init this_module_init(void)
 240{
 241        return i2c_add_driver(&driver);
 242}
 243
 244static void __exit this_module_exit(void)
 245{
 246        i2c_del_driver(&driver);
 247}
 248
 249module_init(this_module_init);
 250module_exit(this_module_exit);
 251
 252MODULE_AUTHOR("Michael Hunold <michael@mihu.de>");
 253MODULE_DESCRIPTION("tda9840 driver");
 254MODULE_LICENSE("GPL");
 255