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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cs3308.c (3337B)

      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 * Cirrus Logic cs3308 8-Channel Analog Volume Control
      4 *
      5 * Copyright (C) 2010 Devin Heitmueller <dheitmueller@kernellabs.com>
      6 * Copyright (C) 2012 Steven Toth <stoth@kernellabs.com>
      7 *
      8 * Derived from cs5345.c Copyright (C) 2007 Hans Verkuil
      9 */
     10
     11
     12#include <linux/module.h>
     13#include <linux/kernel.h>
     14#include <linux/i2c.h>
     15#include <linux/slab.h>
     16#include <linux/videodev2.h>
     17#include <media/v4l2-device.h>
     18
     19MODULE_DESCRIPTION("i2c device driver for cs3308 8-channel volume control");
     20MODULE_AUTHOR("Devin Heitmueller");
     21MODULE_LICENSE("GPL");
     22
     23static inline int cs3308_write(struct v4l2_subdev *sd, u8 reg, u8 value)
     24{
     25	struct i2c_client *client = v4l2_get_subdevdata(sd);
     26
     27	return i2c_smbus_write_byte_data(client, reg, value);
     28}
     29
     30static inline int cs3308_read(struct v4l2_subdev *sd, u8 reg)
     31{
     32	struct i2c_client *client = v4l2_get_subdevdata(sd);
     33
     34	return i2c_smbus_read_byte_data(client, reg);
     35}
     36
     37#ifdef CONFIG_VIDEO_ADV_DEBUG
     38static int cs3308_g_register(struct v4l2_subdev *sd, struct v4l2_dbg_register *reg)
     39{
     40	reg->val = cs3308_read(sd, reg->reg & 0xffff);
     41	reg->size = 1;
     42	return 0;
     43}
     44
     45static int cs3308_s_register(struct v4l2_subdev *sd, const struct v4l2_dbg_register *reg)
     46{
     47	cs3308_write(sd, reg->reg & 0xffff, reg->val & 0xff);
     48	return 0;
     49}
     50#endif
     51
     52/* ----------------------------------------------------------------------- */
     53
     54static const struct v4l2_subdev_core_ops cs3308_core_ops = {
     55#ifdef CONFIG_VIDEO_ADV_DEBUG
     56	.g_register = cs3308_g_register,
     57	.s_register = cs3308_s_register,
     58#endif
     59};
     60
     61static const struct v4l2_subdev_ops cs3308_ops = {
     62	.core = &cs3308_core_ops,
     63};
     64
     65/* ----------------------------------------------------------------------- */
     66
     67static int cs3308_probe(struct i2c_client *client,
     68			const struct i2c_device_id *id)
     69{
     70	struct v4l2_subdev *sd;
     71	unsigned i;
     72
     73	/* Check if the adapter supports the needed features */
     74	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
     75		return -EIO;
     76
     77	if ((i2c_smbus_read_byte_data(client, 0x1c) & 0xf0) != 0xe0)
     78		return -ENODEV;
     79
     80	v4l_info(client, "chip found @ 0x%x (%s)\n",
     81		 client->addr << 1, client->adapter->name);
     82
     83	sd = kzalloc(sizeof(struct v4l2_subdev), GFP_KERNEL);
     84	if (sd == NULL)
     85		return -ENOMEM;
     86
     87	v4l2_i2c_subdev_init(sd, client, &cs3308_ops);
     88
     89	/* Set some reasonable defaults */
     90	cs3308_write(sd, 0x0d, 0x00); /* Power up all channels */
     91	cs3308_write(sd, 0x0e, 0x00); /* Master Power */
     92	cs3308_write(sd, 0x0b, 0x00); /* Device Configuration */
     93	/* Set volume for each channel */
     94	for (i = 1; i <= 8; i++)
     95		cs3308_write(sd, i, 0xd2);
     96	cs3308_write(sd, 0x0a, 0x00); /* Unmute all channels */
     97	return 0;
     98}
     99
    100/* ----------------------------------------------------------------------- */
    101
    102static int cs3308_remove(struct i2c_client *client)
    103{
    104	struct v4l2_subdev *sd = i2c_get_clientdata(client);
    105
    106	v4l2_device_unregister_subdev(sd);
    107	kfree(sd);
    108	return 0;
    109}
    110
    111/* ----------------------------------------------------------------------- */
    112
    113static const struct i2c_device_id cs3308_id[] = {
    114	{ "cs3308", 0 },
    115	{ }
    116};
    117MODULE_DEVICE_TABLE(i2c, cs3308_id);
    118
    119static struct i2c_driver cs3308_driver = {
    120	.driver = {
    121		.name   = "cs3308",
    122	},
    123	.probe          = cs3308_probe,
    124	.remove         = cs3308_remove,
    125	.id_table       = cs3308_id,
    126};
    127
    128module_i2c_driver(cs3308_driver);