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, command: 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, command: 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->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->reg & 0xffff, value: 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{
69 struct v4l2_subdev *sd;
70 unsigned i;
71
72 /* Check if the adapter supports the needed features */
73 if (!i2c_check_functionality(adap: client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
74 return -EIO;
75
76 if ((i2c_smbus_read_byte_data(client, command: 0x1c) & 0xf0) != 0xe0)
77 return -ENODEV;
78
79 v4l_info(client, "chip found @ 0x%x (%s)\n",
80 client->addr << 1, client->adapter->name);
81
82 sd = kzalloc(size: sizeof(struct v4l2_subdev), GFP_KERNEL);
83 if (sd == NULL)
84 return -ENOMEM;
85
86 v4l2_i2c_subdev_init(sd, client, ops: &cs3308_ops);
87
88 /* Set some reasonable defaults */
89 cs3308_write(sd, reg: 0x0d, value: 0x00); /* Power up all channels */
90 cs3308_write(sd, reg: 0x0e, value: 0x00); /* Master Power */
91 cs3308_write(sd, reg: 0x0b, value: 0x00); /* Device Configuration */
92 /* Set volume for each channel */
93 for (i = 1; i <= 8; i++)
94 cs3308_write(sd, reg: i, value: 0xd2);
95 cs3308_write(sd, reg: 0x0a, value: 0x00); /* Unmute all channels */
96 return 0;
97}
98
99/* ----------------------------------------------------------------------- */
100
101static void cs3308_remove(struct i2c_client *client)
102{
103 struct v4l2_subdev *sd = i2c_get_clientdata(client);
104
105 v4l2_device_unregister_subdev(sd);
106 kfree(objp: sd);
107}
108
109/* ----------------------------------------------------------------------- */
110
111static const struct i2c_device_id cs3308_id[] = {
112 { "cs3308", 0 },
113 { }
114};
115MODULE_DEVICE_TABLE(i2c, cs3308_id);
116
117static struct i2c_driver cs3308_driver = {
118 .driver = {
119 .name = "cs3308",
120 },
121 .probe = cs3308_probe,
122 .remove = cs3308_remove,
123 .id_table = cs3308_id,
124};
125
126module_i2c_driver(cs3308_driver);
127

source code of linux/drivers/media/i2c/cs3308.c