drivers/media/i2c/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 "tea6420.h"
  37
  38 MODULE_AUTHOR("Michael Hunold <michael@mihu.de>");
  39 MODULE_DESCRIPTION("tea6420 driver");
  40 MODULE_LICENSE("GPL");
  41
  42 static int debug;
  43 module_param(debug, int, 0644);
  44
  45 MODULE_PARM_DESC(debug, "Debug level (0-1)");
  46
  47
  48 /* make a connection between the input 'i' and the output 'o'
  49    with gain 'g' (note: i = 6 means 'mute') */
  50 static int tea6420_s_routing(struct v4l2_subdev *sd,
  51                              u32 i, u32 o, u32 config)
  52 {
  53         struct i2c_client *client = v4l2_get_subdevdata(sd);
  54         int g = (o >> 4) & 0xf;
  55         u8 byte;
  56         int ret;
  57
  58         o &= 0xf;
  59         v4l2_dbg(1, debug, sd, "i=%d, o=%d, g=%d\n", i, o, g);
  60
  61         /* check if the parameters are valid */
  62         if (i < 1 || i > 6 || o < 1 || o > 4 || g < 0 || g > 6 || g % 2 != 0)
  63                 return -EINVAL;
  64
  65         byte = ((o - 1) << 5);
  66         byte |= (i - 1);
  67
  68         /* to understand this, have a look at the tea6420-specs (p.5) */
  69         switch (g) {
  70         case 0:
  71                 byte |= (3 << 3);
  72                 break;
  73         case 2:
  74                 byte |= (2 << 3);
  75                 break;
  76         case 4:
  77                 byte |= (1 << 3);
  78                 break;
  79         case 6:
  80                 break;
  81         }
  82
  83         ret = i2c_smbus_write_byte(client, byte);
  84         if (ret) {
  85                 v4l2_dbg(1, debug, sd,
  86                         "i2c_smbus_write_byte() failed, ret:%d\n", ret);
  87                 return -EIO;
  88         }
  89         return 0;
  90 }
  91
  92 /* ----------------------------------------------------------------------- */
  93
  94 static const struct v4l2_subdev_audio_ops tea6420_audio_ops = {
  95         .s_routing = tea6420_s_routing,
  96 };
  97
  98 static const struct v4l2_subdev_ops tea6420_ops = {
  99         .audio = &tea6420_audio_ops,
 100 };
 101
 102 static int tea6420_probe(struct i2c_client *client,
 103                           const struct i2c_device_id *id)
 104 {
 105         struct v4l2_subdev *sd;
 106         int err, i;
 107
 108         /* let's see whether this adapter can support what we need */
 109         if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WRITE_BYTE))
 110                 return -EIO;
 111
 112         v4l_info(client, "chip found @ 0x%x (%s)\n",
 113                         client->addr << 1, client->adapter->name);
 114
 115         sd = devm_kzalloc(&client->dev, sizeof(*sd), GFP_KERNEL);
 116         if (sd == NULL)
 117                 return -ENOMEM;
 118         v4l2_i2c_subdev_init(sd, client, &tea6420_ops);
 119
 120         /* set initial values: set "mute"-input to all outputs at gain 0 */
 121         err = 0;
 122         for (i = 1; i < 5; i++)
 123                 err += tea6420_s_routing(sd, 6, i, 0);
 124         if (err) {
 125                 v4l_dbg(1, debug, client, "could not initialize tea6420\n");
 126                 return -ENODEV;
 127         }
 128         return 0;
 129 }
 130
 131 static int tea6420_remove(struct i2c_client *client)
 132 {
 133         struct v4l2_subdev *sd = i2c_get_clientdata(client);
 134
 135         v4l2_device_unregister_subdev(sd);
 136         return 0;
 137 }
 138
 139 static const struct i2c_device_id tea6420_id[] = {
 140         { "tea6420", 0 },
 141         { }
 142 };
 143 MODULE_DEVICE_TABLE(i2c, tea6420_id);
 144
 145 static struct i2c_driver tea6420_driver = {
 146         .driver = {
 147                 .owner  = THIS_MODULE,
 148                 .name   = "tea6420",
 149         },
 150         .probe          = tea6420_probe,
 151         .remove         = tea6420_remove,
 152         .id_table       = tea6420_id,
 153 };
 154
 155 module_i2c_driver(tea6420_driver);