LXR linux/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
  38MODULE_AUTHOR("Michael Hunold <michael@mihu.de>");
  39MODULE_DESCRIPTION("tea6420 driver");
  40MODULE_LICENSE("GPL");
  41
  42static int debug;
  43module_param(debug, int, 0644);
  44
  45MODULE_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') */
  50static 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
  94static const struct v4l2_subdev_audio_ops tea6420_audio_ops = {
  95        .s_routing = tea6420_s_routing,
  96};
  97
  98static const struct v4l2_subdev_ops tea6420_ops = {
  99        .audio = &tea6420_audio_ops,
 100};
 101
 102static 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
 131static 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
 139static const struct i2c_device_id tea6420_id[] = {
 140        { "tea6420", 0 },
 141        { }
 142};
 143MODULE_DEVICE_TABLE(i2c, tea6420_id);
 144
 145static struct i2c_driver tea6420_driver = {
 146        .driver = {
 147                .name   = "tea6420",
 148        },
 149        .probe          = tea6420_probe,
 150        .remove         = tea6420_remove,
 151        .id_table       = tea6420_id,
 152};
 153
 154module_i2c_driver(tea6420_driver);
 155