linux/drivers/media/i2c/tda9840.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3    tda9840 - i2c-driver for the tda9840 by SGS Thomson
   4
   5    Copyright (C) 1998-2003 Michael Hunold <michael@mihu.de>
   6    Copyright (C) 2008 Hans Verkuil <hverkuil@xs4all.nl>
   7
   8    The tda9840 is a stereo/dual sound processor with digital
   9    identification. It can be found at address 0x84 on the i2c-bus.
  10
  11    For detailed information download the specifications directly
  12    from SGS Thomson at http://www.st.com
  13
  14  */
  15
  16
  17#include <linux/module.h>
  18#include <linux/ioctl.h>
  19#include <linux/slab.h>
  20#include <linux/i2c.h>
  21#include <media/v4l2-device.h>
  22
  23MODULE_AUTHOR("Michael Hunold <michael@mihu.de>");
  24MODULE_DESCRIPTION("tda9840 driver");
  25MODULE_LICENSE("GPL");
  26
  27static int debug;
  28module_param(debug, int, 0644);
  29
  30MODULE_PARM_DESC(debug, "Debug level (0-1)");
  31
  32#define SWITCH          0x00
  33#define LEVEL_ADJUST    0x02
  34#define STEREO_ADJUST   0x03
  35#define TEST            0x04
  36
  37#define TDA9840_SET_MUTE                0x00
  38#define TDA9840_SET_MONO                0x10
  39#define TDA9840_SET_STEREO              0x2a
  40#define TDA9840_SET_LANG1               0x12
  41#define TDA9840_SET_LANG2               0x1e
  42#define TDA9840_SET_BOTH                0x1a
  43#define TDA9840_SET_BOTH_R              0x16
  44#define TDA9840_SET_EXTERNAL            0x7a
  45
  46
  47static void tda9840_write(struct v4l2_subdev *sd, u8 reg, u8 val)
  48{
  49        struct i2c_client *client = v4l2_get_subdevdata(sd);
  50
  51        if (i2c_smbus_write_byte_data(client, reg, val))
  52                v4l2_dbg(1, debug, sd, "error writing %02x to %02x\n",
  53                                val, reg);
  54}
  55
  56static int tda9840_status(struct v4l2_subdev *sd)
  57{
  58        struct i2c_client *client = v4l2_get_subdevdata(sd);
  59        int rc;
  60        u8 byte;
  61
  62        rc = i2c_master_recv(client, &byte, 1);
  63        if (rc != 1) {
  64                v4l2_dbg(1, debug, sd,
  65                        "i2c_master_recv() failed\n");
  66                if (rc < 0)
  67                        return rc;
  68                return -EIO;
  69        }
  70
  71        if (byte & 0x80) {
  72                v4l2_dbg(1, debug, sd,
  73                        "TDA9840_DETECT: register contents invalid\n");
  74                return -EINVAL;
  75        }
  76
  77        v4l2_dbg(1, debug, sd, "TDA9840_DETECT: byte: 0x%02x\n", byte);
  78        return byte & 0x60;
  79}
  80
  81static int tda9840_s_tuner(struct v4l2_subdev *sd, const struct v4l2_tuner *t)
  82{
  83        int stat = tda9840_status(sd);
  84        int byte;
  85
  86        if (t->index)
  87                return -EINVAL;
  88
  89        stat = stat < 0 ? 0 : stat;
  90        if (stat == 0 || stat == 0x60) /* mono input */
  91                byte = TDA9840_SET_MONO;
  92        else if (stat == 0x40) /* stereo input */
  93                byte = (t->audmode == V4L2_TUNER_MODE_MONO) ?
  94                        TDA9840_SET_MONO : TDA9840_SET_STEREO;
  95        else { /* bilingual */
  96                switch (t->audmode) {
  97                case V4L2_TUNER_MODE_LANG1_LANG2:
  98                        byte = TDA9840_SET_BOTH;
  99                        break;
 100                case V4L2_TUNER_MODE_LANG2:
 101                        byte = TDA9840_SET_LANG2;
 102                        break;
 103                default:
 104                        byte = TDA9840_SET_LANG1;
 105                        break;
 106                }
 107        }
 108        v4l2_dbg(1, debug, sd, "TDA9840_SWITCH: 0x%02x\n", byte);
 109        tda9840_write(sd, SWITCH, byte);
 110        return 0;
 111}
 112
 113static int tda9840_g_tuner(struct v4l2_subdev *sd, struct v4l2_tuner *t)
 114{
 115        int stat = tda9840_status(sd);
 116
 117        if (stat < 0)
 118                return stat;
 119
 120        t->rxsubchans = V4L2_TUNER_SUB_MONO;
 121
 122        switch (stat & 0x60) {
 123        case 0x00:
 124                t->rxsubchans = V4L2_TUNER_SUB_MONO;
 125                break;
 126        case 0x20:
 127                t->rxsubchans = V4L2_TUNER_SUB_LANG1 | V4L2_TUNER_SUB_LANG2;
 128                break;
 129        case 0x40:
 130                t->rxsubchans = V4L2_TUNER_SUB_STEREO | V4L2_TUNER_SUB_MONO;
 131                break;
 132        default: /* Incorrect detect */
 133                t->rxsubchans = V4L2_TUNER_MODE_MONO;
 134                break;
 135        }
 136        return 0;
 137}
 138
 139/* ----------------------------------------------------------------------- */
 140
 141static const struct v4l2_subdev_tuner_ops tda9840_tuner_ops = {
 142        .s_tuner = tda9840_s_tuner,
 143        .g_tuner = tda9840_g_tuner,
 144};
 145
 146static const struct v4l2_subdev_ops tda9840_ops = {
 147        .tuner = &tda9840_tuner_ops,
 148};
 149
 150/* ----------------------------------------------------------------------- */
 151
 152static int tda9840_probe(struct i2c_client *client,
 153                          const struct i2c_device_id *id)
 154{
 155        struct v4l2_subdev *sd;
 156
 157        /* let's see whether this adapter can support what we need */
 158        if (!i2c_check_functionality(client->adapter,
 159                        I2C_FUNC_SMBUS_READ_BYTE_DATA |
 160                        I2C_FUNC_SMBUS_WRITE_BYTE_DATA))
 161                return -EIO;
 162
 163        v4l_info(client, "chip found @ 0x%x (%s)\n",
 164                        client->addr << 1, client->adapter->name);
 165
 166        sd = devm_kzalloc(&client->dev, sizeof(*sd), GFP_KERNEL);
 167        if (sd == NULL)
 168                return -ENOMEM;
 169        v4l2_i2c_subdev_init(sd, client, &tda9840_ops);
 170
 171        /* set initial values for level & stereo - adjustment, mode */
 172        tda9840_write(sd, LEVEL_ADJUST, 0);
 173        tda9840_write(sd, STEREO_ADJUST, 0);
 174        tda9840_write(sd, SWITCH, TDA9840_SET_STEREO);
 175        return 0;
 176}
 177
 178static int tda9840_remove(struct i2c_client *client)
 179{
 180        struct v4l2_subdev *sd = i2c_get_clientdata(client);
 181
 182        v4l2_device_unregister_subdev(sd);
 183        return 0;
 184}
 185
 186static const struct i2c_device_id tda9840_id[] = {
 187        { "tda9840", 0 },
 188        { }
 189};
 190MODULE_DEVICE_TABLE(i2c, tda9840_id);
 191
 192static struct i2c_driver tda9840_driver = {
 193        .driver = {
 194                .name   = "tda9840",
 195        },
 196        .probe          = tda9840_probe,
 197        .remove         = tda9840_remove,
 198        .id_table       = tda9840_id,
 199};
 200
 201module_i2c_driver(tda9840_driver);
 202