156 lines
4.1 KiB
C
156 lines
4.1 KiB
C
/*
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tea6420 - i2c-driver for the tea6420 by SGS Thomson
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Copyright (C) 1998-2003 Michael Hunold <michael@mihu.de>
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Copyright (C) 2008 Hans Verkuil <hverkuil@xs4all.nl>
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The tea6420 is a bus controlled audio-matrix with 5 stereo inputs,
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4 stereo outputs and gain control for each output.
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It is cascadable, i.e. it can be found at the adresses 0x98
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and 0x9a on the i2c-bus.
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For detailed informations download the specifications directly
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from SGS Thomson at http://www.st.com
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include <linux/module.h>
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#include <linux/ioctl.h>
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#include <linux/i2c.h>
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#include <media/v4l2-common.h>
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#include <media/v4l2-i2c-drv-legacy.h>
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#include "tea6420.h"
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MODULE_AUTHOR("Michael Hunold <michael@mihu.de>");
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MODULE_DESCRIPTION("tea6420 driver");
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MODULE_LICENSE("GPL");
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static int debug;
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module_param(debug, int, 0644);
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MODULE_PARM_DESC(debug, "Debug level (0-1)");
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/* addresses to scan, found only at 0x4c and/or 0x4d (7-Bit) */
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static unsigned short normal_i2c[] = { I2C_ADDR_TEA6420_1, I2C_ADDR_TEA6420_2, I2C_CLIENT_END };
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/* magic definition of all other variables and things */
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I2C_CLIENT_INSMOD;
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/* make a connection between the input 'i' and the output 'o'
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with gain 'g' for the tea6420-client 'client' (note: i = 6 means 'mute') */
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static int tea6420_switch(struct i2c_client *client, int i, int o, int g)
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{
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u8 byte;
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int ret;
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v4l_dbg(1, debug, client, "i=%d, o=%d, g=%d\n", i, o, g);
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/* check if the parameters are valid */
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if (i < 1 || i > 6 || o < 1 || o > 4 || g < 0 || g > 6 || g % 2 != 0)
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return -1;
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byte = ((o - 1) << 5);
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byte |= (i - 1);
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/* to understand this, have a look at the tea6420-specs (p.5) */
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switch (g) {
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case 0:
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byte |= (3 << 3);
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break;
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case 2:
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byte |= (2 << 3);
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break;
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case 4:
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byte |= (1 << 3);
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break;
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case 6:
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break;
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}
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ret = i2c_smbus_write_byte(client, byte);
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if (ret) {
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v4l_dbg(1, debug, client,
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"i2c_smbus_write_byte() failed, ret:%d\n", ret);
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return -EIO;
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}
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return 0;
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}
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static int tea6420_command(struct i2c_client *client, unsigned cmd, void *arg)
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{
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struct tea6420_multiplex *a = (struct tea6420_multiplex *)arg;
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int result = 0;
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switch (cmd) {
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case TEA6420_SWITCH:
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result = tea6420_switch(client, a->in, a->out, a->gain);
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break;
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default:
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return -ENOIOCTLCMD;
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}
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return result;
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}
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/* this function is called by i2c_probe */
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static int tea6420_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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int err, i;
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/* let's see whether this adapter can support what we need */
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if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WRITE_BYTE))
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return -EIO;
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v4l_info(client, "chip found @ 0x%x (%s)\n",
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client->addr << 1, client->adapter->name);
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/* set initial values: set "mute"-input to all outputs at gain 0 */
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err = 0;
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for (i = 1; i < 5; i++) {
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err += tea6420_switch(client, 6, i, 0);
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}
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if (err) {
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v4l_dbg(1, debug, client, "could not initialize tea6420\n");
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kfree(client);
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return -ENODEV;
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}
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return 0;
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}
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static int tea6420_legacy_probe(struct i2c_adapter *adapter)
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{
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/* Let's see whether this is a known adapter we can attach to.
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Prevents conflicts with tvaudio.c. */
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return adapter->id == I2C_HW_SAA7146;
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}
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static const struct i2c_device_id tea6420_id[] = {
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{ "tea6420", 0 },
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{ }
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};
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MODULE_DEVICE_TABLE(i2c, tea6420_id);
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static struct v4l2_i2c_driver_data v4l2_i2c_data = {
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.name = "tea6420",
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.driverid = I2C_DRIVERID_TEA6420,
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.command = tea6420_command,
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.probe = tea6420_probe,
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.legacy_probe = tea6420_legacy_probe,
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.id_table = tea6420_id,
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};
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