release/src-rt-6.x.4708/linux/linux-2.6.36/drivers/media/video/tea6420.c

   1  /*
   2     tea6420 - i2c-driver for the tea6420 by SGS Thomson
   3
   4     Copyright (C) 1998-2003 Michael Hunold <michael@mihu.de>
   5     Copyright (C) 2008 Hans Verkuil <hverkuil@xs4all.nl>
   6
   7     The tea6420 is a bus controlled audio-matrix with 5 stereo inputs,
   8     4 stereo outputs and gain control for each output.
   9     It is cascadable, i.e. it can be found at the addresses 0x98
  10     and 0x9a on the i2c-bus.
  11
  12     For detailed informations download the specifications directly
  13     from SGS Thomson at http://www.st.com
  14
  15     This program is free software; you can redistribute it and/or modify
  16     it under the terms of the GNU General Public License as published by
  17     the Free Software Foundation; either version 2 of the License, or
  18     (at your option) any later version.
  19
  20     This program is distributed in the hope that it will be useful,
  21     but WITHOUT ANY WARRANTY; without even the implied warranty of
  22     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  23     GNU General Public License for more details.
  24
  25     You should have received a copy of the GNU General Public License
  26     along with this program; if not, write to the Free Software
  27     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  28   */
  29
  30
  31 #include <linux/module.h>
  32 #include <linux/ioctl.h>
  33 #include <linux/slab.h>
  34 #include <linux/i2c.h>
  35 #include <media/v4l2-device.h>
  36 #include <media/v4l2-chip-ident.h>
  37 #include <media/v4l2-i2c-drv.h>
  38 #include "tea6420.h"
  39
  40 MODULE_AUTHOR("Michael Hunold <michael@mihu.de>");
  41 MODULE_DESCRIPTION("tea6420 driver");
  42 MODULE_LICENSE("GPL");
  43
  44 static int debug;
  45 module_param(debug, int, 0644);
  46
  47 MODULE_PARM_DESC(debug, "Debug level (0-1)");
  48
  49
  50 /* make a connection between the input 'i' and the output 'o'
  51    with gain 'g' (note: i = 6 means 'mute') */
  52 static int tea6420_s_routing(struct v4l2_subdev *sd,
  53                              u32 i, u32 o, u32 config)
  54 {
  55         struct i2c_client *client = v4l2_get_subdevdata(sd);
  56         int g = (o >> 4) & 0xf;
  57         u8 byte;
  58         int ret;
  59
  60         o &= 0xf;
  61         v4l2_dbg(1, debug, sd, "i=%d, o=%d, g=%d\n", i, o, g);
  62
  63         /* check if the parameters are valid */
  64         if (i < 1 || i > 6 || o < 1 || o > 4 || g < 0 || g > 6 || g % 2 != 0)
  65                 return -EINVAL;
  66
  67         byte = ((o - 1) << 5);
  68         byte |= (i - 1);
  69
  70         /* to understand this, have a look at the tea6420-specs (p.5) */
  71         switch (g) {
  72         case 0:
  73                 byte |= (3 << 3);
  74                 break;
  75         case 2:
  76                 byte |= (2 << 3);
  77                 break;
  78         case 4:
  79                 byte |= (1 << 3);
  80                 break;
  81         case 6:
  82                 break;
  83         }
  84
  85         ret = i2c_smbus_write_byte(client, byte);
  86         if (ret) {
  87                 v4l2_dbg(1, debug, sd,
  88                         "i2c_smbus_write_byte() failed, ret:%d\n", ret);
  89                 return -EIO;
  90         }
  91         return 0;
  92 }
  93
  94 static int tea6420_g_chip_ident(struct v4l2_subdev *sd, struct v4l2_dbg_chip_ident *chip)
  95 {
  96         struct i2c_client *client = v4l2_get_subdevdata(sd);
  97
  98         return v4l2_chip_ident_i2c_client(client, chip, V4L2_IDENT_TEA6420, 0);
  99 }
 100
 101 /* ----------------------------------------------------------------------- */
 102
 103 static const struct v4l2_subdev_core_ops tea6420_core_ops = {
 104         .g_chip_ident = tea6420_g_chip_ident,
 105 };
 106
 107 static const struct v4l2_subdev_audio_ops tea6420_audio_ops = {
 108         .s_routing = tea6420_s_routing,
 109 };
 110
 111 static const struct v4l2_subdev_ops tea6420_ops = {
 112         .core = &tea6420_core_ops,
 113         .audio = &tea6420_audio_ops,
 114 };
 115
 116 static int tea6420_probe(struct i2c_client *client,
 117                           const struct i2c_device_id *id)
 118 {
 119         struct v4l2_subdev *sd;
 120         int err, i;
 121
 122         /* let's see whether this adapter can support what we need */
 123         if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WRITE_BYTE))
 124                 return -EIO;
 125
 126         v4l_info(client, "chip found @ 0x%x (%s)\n",
 127                         client->addr << 1, client->adapter->name);
 128
 129         sd = kmalloc(sizeof(struct v4l2_subdev), GFP_KERNEL);
 130         if (sd == NULL)
 131                 return -ENOMEM;
 132         v4l2_i2c_subdev_init(sd, client, &tea6420_ops);
 133
 134         /* set initial values: set "mute"-input to all outputs at gain 0 */
 135         err = 0;
 136         for (i = 1; i < 5; i++)
 137                 err += tea6420_s_routing(sd, 6, i, 0);
 138         if (err) {
 139                 v4l_dbg(1, debug, client, "could not initialize tea6420\n");
 140                 return -ENODEV;
 141         }
 142         return 0;
 143 }
 144
 145 static int tea6420_remove(struct i2c_client *client)
 146 {
 147         struct v4l2_subdev *sd = i2c_get_clientdata(client);
 148
 149         v4l2_device_unregister_subdev(sd);
 150         kfree(sd);
 151         return 0;
 152 }
 153
 154 static const struct i2c_device_id tea6420_id[] = {
 155         { "tea6420", 0 },
 156         { }
 157 };
 158 MODULE_DEVICE_TABLE(i2c, tea6420_id);
 159
 160 static struct v4l2_i2c_driver_data v4l2_i2c_data = {
 161         .name = "tea6420",
 162         .probe = tea6420_probe,
 163         .remove = tea6420_remove,
 164         .id_table = tea6420_id,
 165 };