root/drivers/media/i2c/tda9840.c

DEFINITIONS

1. tda9840_write
2. tda9840_status
3. tda9840_s_tuner
4. tda9840_g_tuner
5. tda9840_probe
6. tda9840_remove

   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 
  23 MODULE_AUTHOR("Michael Hunold <michael@mihu.de>");
  24 MODULE_DESCRIPTION("tda9840 driver");
  25 MODULE_LICENSE("GPL");
  26 
  27 static int debug;
  28 module_param(debug, int, 0644);
  29 
  30 MODULE_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 
  47 static 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 
  56 static 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 
  81 static 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 
 113 static 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 
 141 static const struct v4l2_subdev_tuner_ops tda9840_tuner_ops = {
 142         .s_tuner = tda9840_s_tuner,
 143         .g_tuner = tda9840_g_tuner,
 144 };
 145 
 146 static const struct v4l2_subdev_ops tda9840_ops = {
 147         .tuner = &tda9840_tuner_ops,
 148 };
 149 
 150 /* ----------------------------------------------------------------------- */
 151 
 152 static 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 
 178 static 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 
 186 static const struct i2c_device_id tda9840_id[] = {
 187         { "tda9840", 0 },
 188         { }
 189 };
 190 MODULE_DEVICE_TABLE(i2c, tda9840_id);
 191 
 192 static 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 
 201 module_i2c_driver(tda9840_driver);