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;               /* insmod parameter */
  35 module_param(debug, int, 0644);
  36 MODULE_PARM_DESC(debug, "Turn on/off device debugging (default:off).");
  37
  38 #define dprintk(args...) \
  39             do { if (debug) { printk("%s: %s()[%d]: ", KBUILD_MODNAME, __func__, __LINE__); printk(args); } } while (0)
  40
  41 #define SWITCH          0x00
  42 #define LEVEL_ADJUST    0x02
  43 #define STEREO_ADJUST   0x03
  44 #define TEST            0x04
  45
  46 /* addresses to scan, found only at 0x42 (7-Bit) */
  47 static unsigned short normal_i2c[] = { I2C_ADDR_TDA9840, I2C_CLIENT_END };
  48
  49 /* magic definition of all other variables and things */
  50 I2C_CLIENT_INSMOD;
  51
  52 static struct i2c_driver driver;
  53 static struct i2c_client client_template;
  54
  55 static int command(struct i2c_client *client, unsigned int cmd, void *arg)
  56 {
  57         int result;
  58         int byte = *(int *)arg;
  59
  60         switch (cmd) {
  61         case TDA9840_SWITCH:
  62
  63                 dprintk("TDA9840_SWITCH: 0x%02x\n", byte);
  64
  65                 if (byte != TDA9840_SET_MONO
  66                     && byte != TDA9840_SET_MUTE
  67                     && byte != TDA9840_SET_STEREO
  68                     && byte != TDA9840_SET_LANG1
  69                     && byte != TDA9840_SET_LANG2
  70                     && byte != TDA9840_SET_BOTH
  71                     && byte != TDA9840_SET_BOTH_R
  72                     && byte != TDA9840_SET_EXTERNAL) {
  73                         return -EINVAL;
  74                 }
  75
  76                 result = i2c_smbus_write_byte_data(client, SWITCH, byte);
  77                 if (result)
  78                         dprintk("i2c_smbus_write_byte() failed, ret:%d\n", result);
  79                 break;
  80
  81         case TDA9840_LEVEL_ADJUST:
  82
  83                 dprintk("TDA9840_LEVEL_ADJUST: %d\n", byte);
  84
  85                 /* check for correct range */
  86                 if (byte > 25 || byte < -20)
  87                         return -EINVAL;
  88
  89                 /* calculate actual value to set, see specs, page 18 */
  90                 byte /= 5;
  91                 if (0 < byte)
  92                         byte += 0x8;
  93                 else
  94                         byte = -byte;
  95
  96                 result = i2c_smbus_write_byte_data(client, LEVEL_ADJUST, byte);
  97                 if (result)
  98                         dprintk("i2c_smbus_write_byte() failed, ret:%d\n", result);
  99                 break;
 100
 101         case TDA9840_STEREO_ADJUST:
 102
 103                 dprintk("TDA9840_STEREO_ADJUST: %d\n", byte);
 104
 105                 /* check for correct range */
 106                 if (byte > 25 || byte < -24)
 107                         return -EINVAL;
 108
 109                 /* calculate actual value to set */
 110                 byte /= 5;
 111                 if (0 < byte)
 112                         byte += 0x20;
 113                 else
 114                         byte = -byte;
 115
 116                 result = i2c_smbus_write_byte_data(client, STEREO_ADJUST, byte);
 117                 if (result)
 118                         dprintk("i2c_smbus_write_byte() failed, ret:%d\n", result);
 119                 break;
 120
 121         case TDA9840_DETECT: {
 122                 int *ret = (int *)arg;
 123
 124                 byte = i2c_smbus_read_byte_data(client, STEREO_ADJUST);
 125                 if (byte == -1) {
 126                         dprintk("i2c_smbus_read_byte_data() failed\n");
 127                         return -EIO;
 128                 }
 129
 130                 if (0 != (byte & 0x80)) {
 131                         dprintk("TDA9840_DETECT: register contents invalid\n");
 132                         return -EINVAL;
 133                 }
 134
 135                 dprintk("TDA9840_DETECT: byte: 0x%02x\n", byte);
 136                 *ret = ((byte & 0x60) >> 5);
 137                 result = 0;
 138                 break;
 139         }
 140         case TDA9840_TEST:
 141                 dprintk("TDA9840_TEST: 0x%02x\n", byte);
 142
 143                 /* mask out irrelevant bits */
 144                 byte &= 0x3;
 145
 146                 result = i2c_smbus_write_byte_data(client, TEST, byte);
 147                 if (result)
 148                         dprintk("i2c_smbus_write_byte() failed, ret:%d\n", result);
 149                 break;
 150         default:
 151                 return -ENOIOCTLCMD;
 152         }
 153
 154         if (result)
 155                 return -EIO;
 156
 157         return 0;
 158 }
 159
 160 static int detect(struct i2c_adapter *adapter, int address, int kind)
 161 {
 162         struct i2c_client *client;
 163         int result = 0;
 164
 165         int byte = 0x0;
 166
 167         /* let's see whether this adapter can support what we need */
 168         if (0 == i2c_check_functionality(adapter,
 169                                     I2C_FUNC_SMBUS_READ_BYTE_DATA |
 170                                     I2C_FUNC_SMBUS_WRITE_BYTE_DATA)) {
 171                 return 0;
 172         }
 173
 174         /* allocate memory for client structure */
 175         client = kmalloc(sizeof(struct i2c_client), GFP_KERNEL);
 176         if (!client) {
 177                 printk("not enough kernel memory\n");
 178                 return -ENOMEM;
 179         }
 180
 181         /* fill client structure */
 182         memcpy(client, &client_template, sizeof(struct i2c_client));
 183         client->addr = address;
 184         client->adapter = adapter;
 185
 186         /* tell the i2c layer a new client has arrived */
 187         if (0 != (result = i2c_attach_client(client))) {
 188                 kfree(client);
 189                 return result;
 190         }
 191
 192         /* set initial values for level & stereo - adjustment, mode */
 193         byte = 0;
 194         result  = command(client, TDA9840_LEVEL_ADJUST, &byte);
 195         result += command(client, TDA9840_STEREO_ADJUST, &byte);
 196         byte = TDA9840_SET_MONO;
 197         result = command(client, TDA9840_SWITCH, &byte);
 198         if (result) {
 199                 dprintk("could not initialize tda9840\n");
 200                 return -ENODEV;
 201         }
 202
 203         printk("tda9840: detected @ 0x%02x on adapter %s\n", address, &client->adapter->name[0]);
 204         return 0;
 205 }
 206
 207 static int attach(struct i2c_adapter *adapter)
 208 {
 209         /* let's see whether this is a know adapter we can attach to */
 210         if (adapter->id != I2C_HW_SAA7146) {
 211                 dprintk("refusing to probe on unknown adapter [name='%s',id=0x%x]\n", adapter->name, adapter->id);
 212                 return -ENODEV;
 213         }
 214
 215         return i2c_probe(adapter, &addr_data, &detect);
 216 }
 217
 218 static int detach(struct i2c_client *client)
 219 {
 220         int ret = i2c_detach_client(client);
 221         kfree(client);
 222         return ret;
 223 }
 224
 225 static struct i2c_driver driver = {
 226         .driver = {
 227                 .name = "tda9840",
 228         },
 229         .id     = I2C_DRIVERID_TDA9840,
 230         .attach_adapter = attach,
 231         .detach_client  = detach,
 232         .command        = command,
 233 };
 234
 235 static struct i2c_client client_template = {
 236         .name = "tda9840",
 237         .driver = &driver,
 238 };
 239
 240 static int __init this_module_init(void)
 241 {
 242         return i2c_add_driver(&driver);
 243 }
 244
 245 static void __exit this_module_exit(void)
 246 {
 247         i2c_del_driver(&driver);
 248 }
 249
 250 module_init(this_module_init);
 251 module_exit(this_module_exit);
 252
 253 MODULE_AUTHOR("Michael Hunold <michael@mihu.de>");
 254 MODULE_DESCRIPTION("tda9840 driver");
 255 MODULE_LICENSE("GPL");