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 <media/v4l2-chip-ident.h>
  37 #include "tea6420.h"
  38
  39 MODULE_AUTHOR("Michael Hunold <michael@mihu.de>");
  40 MODULE_DESCRIPTION("tea6420 driver");
  41 MODULE_LICENSE("GPL");
  42
  43 static int debug;
  44 module_param(debug, int, 0644);
  45
  46 MODULE_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') */
  51 static 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
  93 static 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
 102 static const struct v4l2_subdev_core_ops tea6420_core_ops = {
 103         .g_chip_ident = tea6420_g_chip_ident,
 104 };
 105
 106 static const struct v4l2_subdev_audio_ops tea6420_audio_ops = {
 107         .s_routing = tea6420_s_routing,
 108 };
 109
 110 static const struct v4l2_subdev_ops tea6420_ops = {
 111         .core = &tea6420_core_ops,
 112         .audio = &tea6420_audio_ops,
 113 };
 114
 115 static 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 = kzalloc(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
 144 static 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
 153 static const struct i2c_device_id tea6420_id[] = {
 154         { "tea6420", 0 },
 155         { }
 156 };
 157 MODULE_DEVICE_TABLE(i2c, tea6420_id);
 158
 159 static 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
 169 module_i2c_driver(tea6420_driver);