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 #include <linux/module.h>
  28 #include <linux/ioctl.h>
  29 #include <linux/i2c.h>
  30
  31 #include "tda9840.h"
  32
  33 static int debug = 0;           /* insmod parameter */
  34 module_param(debug, int, 0644);
  35 MODULE_PARM_DESC(debug, "Turn on/off device debugging (default:off).");
  36 #define dprintk(args...) \
  37             do { if (debug) { printk("%s: %s()[%d]: ",__stringify(KBUILD_MODNAME), __FUNCTION__, __LINE__); printk(args); } } while (0)
  38
  39 #define SWITCH          0x00
  40 #define LEVEL_ADJUST    0x02
  41 #define STEREO_ADJUST   0x03
  42 #define TEST            0x04
  43
  44 /* addresses to scan, found only at 0x42 (7-Bit) */
  45 static unsigned short normal_i2c[] = { I2C_TDA9840, I2C_CLIENT_END };
  46
  47 /* magic definition of all other variables and things */
  48 I2C_CLIENT_INSMOD;
  49
  50 static struct i2c_driver driver;
  51 static struct i2c_client client_template;
  52
  53 static int command(struct i2c_client *client, unsigned int cmd, void *arg)
  54 {
  55         int result;
  56         int byte = *(int *)arg;
  57
  58         switch (cmd) {
  59         case TDA9840_SWITCH:
  60
  61                 dprintk("TDA9840_SWITCH: 0x%02x\n", byte);
  62
  63                 if (byte != TDA9840_SET_MONO
  64                     && byte != TDA9840_SET_MUTE
  65                     && byte != TDA9840_SET_STEREO
  66                     && byte != TDA9840_SET_LANG1
  67                     && byte != TDA9840_SET_LANG2
  68                     && byte != TDA9840_SET_BOTH
  69                     && byte != TDA9840_SET_BOTH_R
  70                     && byte != TDA9840_SET_EXTERNAL) {
  71                         return -EINVAL;
  72                 }
  73
  74                 result = i2c_smbus_write_byte_data(client, SWITCH, byte);
  75                 if (result)
  76                         dprintk("i2c_smbus_write_byte() failed, ret:%d\n", result);
  77                 break;
  78
  79         case TDA9840_LEVEL_ADJUST:
  80
  81                 dprintk("TDA9840_LEVEL_ADJUST: %d\n", byte);
  82
  83                 /* check for correct range */
  84                 if (byte > 25 || byte < -20)
  85                         return -EINVAL;
  86
  87                 /* calculate actual value to set, see specs, page 18 */
  88                 byte /= 5;
  89                 if (0 < byte)
  90                         byte += 0x8;
  91                 else
  92                         byte = -byte;
  93
  94                 result = i2c_smbus_write_byte_data(client, LEVEL_ADJUST, byte);
  95                 if (result)
  96                         dprintk("i2c_smbus_write_byte() failed, ret:%d\n", result);
  97                 break;
  98
  99         case TDA9840_STEREO_ADJUST:
 100
 101                 dprintk("TDA9840_STEREO_ADJUST: %d\n", byte);
 102
 103                 /* check for correct range */
 104                 if (byte > 25 || byte < -24)
 105                         return -EINVAL;
 106
 107                 /* calculate actual value to set */
 108                 byte /= 5;
 109                 if (0 < byte)
 110                         byte += 0x20;
 111                 else
 112                         byte = -byte;
 113
 114                 result = i2c_smbus_write_byte_data(client, STEREO_ADJUST, byte);
 115                 if (result)
 116                         dprintk("i2c_smbus_write_byte() failed, ret:%d\n", result);
 117                 break;
 118
 119         case TDA9840_DETECT: {
 120                 int *ret = (int *)arg;
 121
 122                 byte = i2c_smbus_read_byte_data(client, STEREO_ADJUST);
 123                 if (byte == -1) {
 124                         dprintk("i2c_smbus_read_byte_data() failed\n");
 125                         return -EIO;
 126                 }
 127
 128                 if (0 != (byte & 0x80)) {
 129                         dprintk("TDA9840_DETECT: register contents invalid\n");
 130                         return -EINVAL;
 131                 }
 132
 133                 dprintk("TDA9840_DETECT: byte: 0x%02x\n", byte);
 134                 *ret = ((byte & 0x60) >> 5);
 135                 result = 0;
 136                 break;
 137         }
 138         case TDA9840_TEST:
 139                 dprintk("TDA9840_TEST: 0x%02x\n", byte);
 140
 141                 /* mask out irrelevant bits */
 142                 byte &= 0x3;
 143
 144                 result = i2c_smbus_write_byte_data(client, TEST, byte);
 145                 if (result)
 146                         dprintk("i2c_smbus_write_byte() failed, ret:%d\n", result);
 147                 break;
 148         default:
 149                 return -ENOIOCTLCMD;
 150         }
 151
 152         if (result)
 153                 return -EIO;
 154
 155         return 0;
 156 }
 157
 158 static int detect(struct i2c_adapter *adapter, int address, int kind)
 159 {
 160         struct i2c_client *client;
 161         int result = 0;
 162
 163         int byte = 0x0;
 164
 165         /* let's see whether this adapter can support what we need */
 166         if (0 == i2c_check_functionality(adapter,
 167                                     I2C_FUNC_SMBUS_READ_BYTE_DATA |
 168                                     I2C_FUNC_SMBUS_WRITE_BYTE_DATA)) {
 169                 return 0;
 170         }
 171
 172         /* allocate memory for client structure */
 173         client = kmalloc(sizeof(struct i2c_client), GFP_KERNEL);
 174         if (0 == client) {
 175                 printk("not enough kernel memory\n");
 176                 return -ENOMEM;
 177         }
 178
 179         /* fill client structure */
 180         memcpy(client, &client_template, sizeof(struct i2c_client));
 181         client->addr = address;
 182         client->adapter = adapter;
 183
 184         /* tell the i2c layer a new client has arrived */
 185         if (0 != (result = i2c_attach_client(client))) {
 186                 kfree(client);
 187                 return result;
 188         }
 189
 190         /* set initial values for level & stereo - adjustment, mode */
 191         byte = 0;
 192         result  = command(client, TDA9840_LEVEL_ADJUST, &byte);
 193         result += command(client, TDA9840_STEREO_ADJUST, &byte);
 194         byte = TDA9840_SET_MONO;
 195         result = command(client, TDA9840_SWITCH, &byte);
 196         if (result) {
 197                 dprintk("could not initialize tda9840\n");
 198                 return -ENODEV;
 199         }
 200
 201         printk("tda9840: detected @ 0x%02x on adapter %s\n", address, &client->adapter->name[0]);
 202         return 0;
 203 }
 204
 205 static int attach(struct i2c_adapter *adapter)
 206 {
 207         /* let's see whether this is a know adapter we can attach to */
 208         if (adapter->id != I2C_HW_SAA7146) {
 209                 dprintk("refusing to probe on unknown adapter [name='%s',id=0x%x]\n", adapter->name, adapter->id);
 210                 return -ENODEV;
 211         }
 212
 213         return i2c_probe(adapter, &addr_data, &detect);
 214 }
 215
 216 static int detach(struct i2c_client *client)
 217 {
 218         int ret = i2c_detach_client(client);
 219         kfree(client);
 220         return ret;
 221 }
 222
 223 static struct i2c_driver driver = {
 224         .owner  = THIS_MODULE,
 225         .name   = "tda9840",
 226         .id     = I2C_DRIVERID_TDA9840,
 227         .flags  = I2C_DF_NOTIFY,
 228         .attach_adapter = attach,
 229         .detach_client  = detach,
 230         .command        = command,
 231 };
 232
 233 static struct i2c_client client_template = {
 234         .name = "tda9840",
 235         .driver = &driver,
 236 };
 237
 238 static int __init this_module_init(void)
 239 {
 240         return i2c_add_driver(&driver);
 241 }
 242
 243 static void __exit this_module_exit(void)
 244 {
 245         i2c_del_driver(&driver);
 246 }
 247
 248 module_init(this_module_init);
 249 module_exit(this_module_exit);
 250
 251 MODULE_AUTHOR("Michael Hunold <michael@mihu.de>");
 252 MODULE_DESCRIPTION("tda9840 driver");
 253 MODULE_LICENSE("GPL");