cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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tda9840.c (4893B)


      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);