LXR linux/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 "tea6420.h"
  38
  39MODULE_AUTHOR("Michael Hunold <michael@mihu.de>");
  40MODULE_DESCRIPTION("tea6420 driver");
  41MODULE_LICENSE("GPL");
  42
  43static int debug;
  44module_param(debug, int, 0644);
  45
  46MODULE_PARM_DESC(debug, "Debug level (0-1)");
  47
  48
  49/* make a connection between the input 'i' and the output 'o'
  50   with gain 'g' (note: i = 6 means 'mute') */
  51static int tea6420_s_routing(struct v4l2_subdev *sd,
  52                             u32 i, u32 o, u32 config)
  53{
  54        struct i2c_client *client = v4l2_get_subdevdata(sd);
  55        int g = (o >> 4) & 0xf;
  56        u8 byte;
  57        int ret;
  58
  59        o &= 0xf;
  60        v4l2_dbg(1, debug, sd, "i=%d, o=%d, g=%d\n", i, o, g);
  61
  62        /* check if the parameters are valid */
  63        if (i < 1 || i > 6 || o < 1 || o > 4 || g < 0 || g > 6 || g % 2 != 0)
  64                return -EINVAL;
  65
  66        byte = ((o - 1) << 5);
  67        byte |= (i - 1);
  68
  69        /* to understand this, have a look at the tea6420-specs (p.5) */
  70        switch (g) {
  71        case 0:
  72                byte |= (3 << 3);
  73                break;
  74        case 2:
  75                byte |= (2 << 3);
  76                break;
  77        case 4:
  78                byte |= (1 << 3);
  79                break;
  80        case 6:
  81                break;
  82        }
  83
  84        ret = i2c_smbus_write_byte(client, byte);
  85        if (ret) {
  86                v4l2_dbg(1, debug, sd,
  87                        "i2c_smbus_write_byte() failed, ret:%d\n", ret);
  88                return -EIO;
  89        }
  90        return 0;
  91}
  92
  93static int tea6420_g_chip_ident(struct v4l2_subdev *sd, struct v4l2_dbg_chip_ident *chip)
  94{
  95        struct i2c_client *client = v4l2_get_subdevdata(sd);
  96
  97        return v4l2_chip_ident_i2c_client(client, chip, V4L2_IDENT_TEA6420, 0);
  98}
  99
 100/* ----------------------------------------------------------------------- */
 101
 102static const struct v4l2_subdev_core_ops tea6420_core_ops = {
 103        .g_chip_ident = tea6420_g_chip_ident,
 104};
 105
 106static const struct v4l2_subdev_audio_ops tea6420_audio_ops = {
 107        .s_routing = tea6420_s_routing,
 108};
 109
 110static const struct v4l2_subdev_ops tea6420_ops = {
 111        .core = &tea6420_core_ops,
 112        .audio = &tea6420_audio_ops,
 113};
 114
 115static int tea6420_probe(struct i2c_client *client,
 116                          const struct i2c_device_id *id)
 117{
 118        struct v4l2_subdev *sd;
 119        int err, i;
 120
 121        /* let's see whether this adapter can support what we need */
 122        if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WRITE_BYTE))
 123                return -EIO;
 124
 125        v4l_info(client, "chip found @ 0x%x (%s)\n",
 126                        client->addr << 1, client->adapter->name);
 127
 128        sd = kmalloc(sizeof(struct v4l2_subdev), GFP_KERNEL);
 129        if (sd == NULL)
 130                return -ENOMEM;
 131        v4l2_i2c_subdev_init(sd, client, &tea6420_ops);
 132
 133        /* set initial values: set "mute"-input to all outputs at gain 0 */
 134        err = 0;
 135        for (i = 1; i < 5; i++)
 136                err += tea6420_s_routing(sd, 6, i, 0);
 137        if (err) {
 138                v4l_dbg(1, debug, client, "could not initialize tea6420\n");
 139                return -ENODEV;
 140        }
 141        return 0;
 142}
 143
 144static int tea6420_remove(struct i2c_client *client)
 145{
 146        struct v4l2_subdev *sd = i2c_get_clientdata(client);
 147
 148        v4l2_device_unregister_subdev(sd);
 149        kfree(sd);
 150        return 0;
 151}
 152
 153static const struct i2c_device_id tea6420_id[] = {
 154        { "tea6420", 0 },
 155        { }
 156};
 157MODULE_DEVICE_TABLE(i2c, tea6420_id);
 158
 159static struct i2c_driver tea6420_driver = {
 160        .driver = {
 161                .owner  = THIS_MODULE,
 162                .name   = "tea6420",
 163        },
 164        .probe          = tea6420_probe,
 165        .remove         = tea6420_remove,
 166        .id_table       = tea6420_id,
 167};
 168
 169static __init int init_tea6420(void)
 170{
 171        return i2c_add_driver(&tea6420_driver);
 172}
 173
 174static __exit void exit_tea6420(void)
 175{
 176        i2c_del_driver(&tea6420_driver);
 177}
 178
 179module_init(init_tea6420);
 180module_exit(exit_tea6420);
 181