linux/drivers/media/i2c/m52790.c
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   1/*
   2 * m52790 i2c ivtv driver.
   3 * Copyright (C) 2007  Hans Verkuil
   4 *
   5 * A/V source switching Mitsubishi M52790SP/FP
   6 *
   7 * This program is free software; you can redistribute it and/or modify
   8 * it under the terms of the GNU General Public License as published by
   9 * the Free Software Foundation; either version 2 of the License, or
  10 * (at your option) any later version.
  11 *
  12 * This program is distributed in the hope that it will be useful,
  13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 * GNU General Public License for more details.
  16 */
  17
  18
  19#include <linux/module.h>
  20#include <linux/types.h>
  21#include <linux/slab.h>
  22#include <linux/ioctl.h>
  23#include <linux/uaccess.h>
  24#include <linux/i2c.h>
  25#include <linux/videodev2.h>
  26#include <media/i2c/m52790.h>
  27#include <media/v4l2-device.h>
  28
  29MODULE_DESCRIPTION("i2c device driver for m52790 A/V switch");
  30MODULE_AUTHOR("Hans Verkuil");
  31MODULE_LICENSE("GPL");
  32
  33
  34struct m52790_state {
  35        struct v4l2_subdev sd;
  36        u16 input;
  37        u16 output;
  38};
  39
  40static inline struct m52790_state *to_state(struct v4l2_subdev *sd)
  41{
  42        return container_of(sd, struct m52790_state, sd);
  43}
  44
  45/* ----------------------------------------------------------------------- */
  46
  47static int m52790_write(struct v4l2_subdev *sd)
  48{
  49        struct m52790_state *state = to_state(sd);
  50        struct i2c_client *client = v4l2_get_subdevdata(sd);
  51
  52        u8 sw1 = (state->input | state->output) & 0xff;
  53        u8 sw2 = (state->input | state->output) >> 8;
  54
  55        return i2c_smbus_write_byte_data(client, sw1, sw2);
  56}
  57
  58/* Note: audio and video are linked and cannot be switched separately.
  59   So audio and video routing commands are identical for this chip.
  60   In theory the video amplifier and audio modes could be handled
  61   separately for the output, but that seems to be overkill right now.
  62   The same holds for implementing an audio mute control, this is now
  63   part of the audio output routing. The normal case is that another
  64   chip takes care of the actual muting so making it part of the
  65   output routing seems to be the right thing to do for now. */
  66static int m52790_s_routing(struct v4l2_subdev *sd,
  67                            u32 input, u32 output, u32 config)
  68{
  69        struct m52790_state *state = to_state(sd);
  70
  71        state->input = input;
  72        state->output = output;
  73        m52790_write(sd);
  74        return 0;
  75}
  76
  77#ifdef CONFIG_VIDEO_ADV_DEBUG
  78static int m52790_g_register(struct v4l2_subdev *sd, struct v4l2_dbg_register *reg)
  79{
  80        struct m52790_state *state = to_state(sd);
  81
  82        if (reg->reg != 0)
  83                return -EINVAL;
  84        reg->size = 1;
  85        reg->val = state->input | state->output;
  86        return 0;
  87}
  88
  89static int m52790_s_register(struct v4l2_subdev *sd, const struct v4l2_dbg_register *reg)
  90{
  91        struct m52790_state *state = to_state(sd);
  92
  93        if (reg->reg != 0)
  94                return -EINVAL;
  95        state->input = reg->val & 0x0303;
  96        state->output = reg->val & ~0x0303;
  97        m52790_write(sd);
  98        return 0;
  99}
 100#endif
 101
 102static int m52790_log_status(struct v4l2_subdev *sd)
 103{
 104        struct m52790_state *state = to_state(sd);
 105
 106        v4l2_info(sd, "Switch 1: %02x\n",
 107                        (state->input | state->output) & 0xff);
 108        v4l2_info(sd, "Switch 2: %02x\n",
 109                        (state->input | state->output) >> 8);
 110        return 0;
 111}
 112
 113/* ----------------------------------------------------------------------- */
 114
 115static const struct v4l2_subdev_core_ops m52790_core_ops = {
 116        .log_status = m52790_log_status,
 117#ifdef CONFIG_VIDEO_ADV_DEBUG
 118        .g_register = m52790_g_register,
 119        .s_register = m52790_s_register,
 120#endif
 121};
 122
 123static const struct v4l2_subdev_audio_ops m52790_audio_ops = {
 124        .s_routing = m52790_s_routing,
 125};
 126
 127static const struct v4l2_subdev_video_ops m52790_video_ops = {
 128        .s_routing = m52790_s_routing,
 129};
 130
 131static const struct v4l2_subdev_ops m52790_ops = {
 132        .core = &m52790_core_ops,
 133        .audio = &m52790_audio_ops,
 134        .video = &m52790_video_ops,
 135};
 136
 137/* ----------------------------------------------------------------------- */
 138
 139/* i2c implementation */
 140
 141static int m52790_probe(struct i2c_client *client,
 142                        const struct i2c_device_id *id)
 143{
 144        struct m52790_state *state;
 145        struct v4l2_subdev *sd;
 146
 147        /* Check if the adapter supports the needed features */
 148        if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 149                return -EIO;
 150
 151        v4l_info(client, "chip found @ 0x%x (%s)\n",
 152                        client->addr << 1, client->adapter->name);
 153
 154        state = devm_kzalloc(&client->dev, sizeof(*state), GFP_KERNEL);
 155        if (state == NULL)
 156                return -ENOMEM;
 157
 158        sd = &state->sd;
 159        v4l2_i2c_subdev_init(sd, client, &m52790_ops);
 160        state->input = M52790_IN_TUNER;
 161        state->output = M52790_OUT_STEREO;
 162        m52790_write(sd);
 163        return 0;
 164}
 165
 166static int m52790_remove(struct i2c_client *client)
 167{
 168        struct v4l2_subdev *sd = i2c_get_clientdata(client);
 169
 170        v4l2_device_unregister_subdev(sd);
 171        return 0;
 172}
 173
 174/* ----------------------------------------------------------------------- */
 175
 176static const struct i2c_device_id m52790_id[] = {
 177        { "m52790", 0 },
 178        { }
 179};
 180MODULE_DEVICE_TABLE(i2c, m52790_id);
 181
 182static struct i2c_driver m52790_driver = {
 183        .driver = {
 184                .name   = "m52790",
 185        },
 186        .probe          = m52790_probe,
 187        .remove         = m52790_remove,
 188        .id_table       = m52790_id,
 189};
 190
 191module_i2c_driver(m52790_driver);
 192