drivers/media/video/tda9840.c

   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
  34 static int debug = 0;           /* insmod parameter */
  35 module_param(debug, int, 0644);
  36 MODULE_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) */
  46 static unsigned short normal_i2c[] = { I2C_ADDR_TDA9840, I2C_CLIENT_END };
  47
  48 /* magic definition of all other variables and things */
  49 I2C_CLIENT_INSMOD;
  50
  51 static struct i2c_driver driver;
  52 static struct i2c_client client_template;
  53
  54 static 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
 159 static 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
 206 static 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
 217 static int detach(struct i2c_client *client)
 218 {
 219         int ret = i2c_detach_client(client);
 220         kfree(client);
 221         return ret;
 222 }
 223
 224 static 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
 234 static struct i2c_client client_template = {
 235         .name = "tda9840",
 236         .driver = &driver,
 237 };
 238
 239 static int __init this_module_init(void)
 240 {
 241         return i2c_add_driver(&driver);
 242 }
 243
 244 static void __exit this_module_exit(void)
 245 {
 246         i2c_del_driver(&driver);
 247 }
 248
 249 module_init(this_module_init);
 250 module_exit(this_module_exit);
 251
 252 MODULE_AUTHOR("Michael Hunold <michael@mihu.de>");
 253 MODULE_DESCRIPTION("tda9840 driver");
 254 MODULE_LICENSE("GPL");