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1// SPDX-License-Identifier: GPL-2.0-or-later2 /*3 tea6420 - i2c-driver for the tea6420 by SGS Thomson4 5 Copyright (C) 1998-2003 Michael Hunold <michael@mihu.de>6 Copyright (C) 2008 Hans Verkuil <hverkuil@xs4all.nl>7 8 The tea6420 is a bus controlled audio-matrix with 5 stereo inputs,9 4 stereo outputs and gain control for each output.10 It is cascadable, i.e. it can be found at the addresses 0x9811 and 0x9a on the i2c-bus.12 13 For detailed information download the specifications directly14 from SGS Thomson at http://www.st.com15 16 */17 18 19#include <linux/module.h>20#include <linux/ioctl.h>21#include <linux/slab.h>22#include <linux/i2c.h>23#include <media/v4l2-device.h>24#include "tea6420.h"25 26MODULE_AUTHOR("Michael Hunold <michael@mihu.de>");27MODULE_DESCRIPTION("tea6420 driver");28MODULE_LICENSE("GPL");29 30static int debug;31module_param(debug, int, 0644);32 33MODULE_PARM_DESC(debug, "Debug level (0-1)");34 35 36/* make a connection between the input 'i' and the output 'o'37 with gain 'g' (note: i = 6 means 'mute') */38static int tea6420_s_routing(struct v4l2_subdev *sd,39 u32 i, u32 o, u32 config)40{41 struct i2c_client *client = v4l2_get_subdevdata(sd);42 int g = (o >> 4) & 0xf;43 u8 byte;44 int ret;45 46 o &= 0xf;47 v4l2_dbg(1, debug, sd, "i=%d, o=%d, g=%d\n", i, o, g);48 49 /* check if the parameters are valid */50 if (i < 1 || i > 6 || o < 1 || o > 4 || g < 0 || g > 6 || g % 2 != 0)51 return -EINVAL;52 53 byte = ((o - 1) << 5);54 byte |= (i - 1);55 56 /* to understand this, have a look at the tea6420-specs (p.5) */57 switch (g) {58 case 0:59 byte |= (3 << 3);60 break;61 case 2:62 byte |= (2 << 3);63 break;64 case 4:65 byte |= (1 << 3);66 break;67 case 6:68 break;69 }70 71 ret = i2c_smbus_write_byte(client, byte);72 if (ret) {73 v4l2_dbg(1, debug, sd,74 "i2c_smbus_write_byte() failed, ret:%d\n", ret);75 return -EIO;76 }77 return 0;78}79 80/* ----------------------------------------------------------------------- */81 82static const struct v4l2_subdev_audio_ops tea6420_audio_ops = {83 .s_routing = tea6420_s_routing,84};85 86static const struct v4l2_subdev_ops tea6420_ops = {87 .audio = &tea6420_audio_ops,88};89 90static int tea6420_probe(struct i2c_client *client)91{92 struct v4l2_subdev *sd;93 int err, i;94 95 /* let's see whether this adapter can support what we need */96 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WRITE_BYTE))97 return -EIO;98 99 v4l_info(client, "chip found @ 0x%x (%s)\n",100 client->addr << 1, client->adapter->name);101 102 sd = devm_kzalloc(&client->dev, sizeof(*sd), GFP_KERNEL);103 if (sd == NULL)104 return -ENOMEM;105 v4l2_i2c_subdev_init(sd, client, &tea6420_ops);106 107 /* set initial values: set "mute"-input to all outputs at gain 0 */108 err = 0;109 for (i = 1; i < 5; i++)110 err += tea6420_s_routing(sd, 6, i, 0);111 if (err) {112 v4l_dbg(1, debug, client, "could not initialize tea6420\n");113 return -ENODEV;114 }115 return 0;116}117 118static void tea6420_remove(struct i2c_client *client)119{120 struct v4l2_subdev *sd = i2c_get_clientdata(client);121 122 v4l2_device_unregister_subdev(sd);123}124 125static const struct i2c_device_id tea6420_id[] = {126 { "tea6420" },127 { }128};129MODULE_DEVICE_TABLE(i2c, tea6420_id);130 131static struct i2c_driver tea6420_driver = {132 .driver = {133 .name = "tea6420",134 },135 .probe = tea6420_probe,136 .remove = tea6420_remove,137 .id_table = tea6420_id,138};139 140module_i2c_driver(tea6420_driver);141