1 /* 2 * Cirrus Logic cs3308 8-Channel Analog Volume Control 3 * 4 * Copyright (C) 2010 Devin Heitmueller <dheitmueller@kernellabs.com> 5 * Copyright (C) 2012 Steven Toth <stoth@kernellabs.com> 6 * 7 * Derived from cs5345.c Copyright (C) 2007 Hans Verkuil 8 * 9 * This program is free software; you can redistribute it and/or modify 10 * it under the terms of the GNU General Public License as published by 11 * the Free Software Foundation; either version 2 of the License, or 12 * (at your option) any later version. 13 * 14 * This program is distributed in the hope that it will be useful, 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 * GNU General Public License for more details. 18 */ 19 20 21 #include <linux/module.h> 22 #include <linux/kernel.h> 23 #include <linux/i2c.h> 24 #include <linux/slab.h> 25 #include <linux/videodev2.h> 26 #include <media/v4l2-device.h> 27 28 MODULE_DESCRIPTION("i2c device driver for cs3308 8-channel volume control"); 29 MODULE_AUTHOR("Devin Heitmueller"); 30 MODULE_LICENSE("GPL"); 31 32 static inline int cs3308_write(struct v4l2_subdev *sd, u8 reg, u8 value) 33 { 34 struct i2c_client *client = v4l2_get_subdevdata(sd); 35 36 return i2c_smbus_write_byte_data(client, reg, value); 37 } 38 39 static inline int cs3308_read(struct v4l2_subdev *sd, u8 reg) 40 { 41 struct i2c_client *client = v4l2_get_subdevdata(sd); 42 43 return i2c_smbus_read_byte_data(client, reg); 44 } 45 46 #ifdef CONFIG_VIDEO_ADV_DEBUG 47 static int cs3308_g_register(struct v4l2_subdev *sd, struct v4l2_dbg_register *reg) 48 { 49 reg->val = cs3308_read(sd, reg->reg & 0xffff); 50 reg->size = 1; 51 return 0; 52 } 53 54 static int cs3308_s_register(struct v4l2_subdev *sd, const struct v4l2_dbg_register *reg) 55 { 56 cs3308_write(sd, reg->reg & 0xffff, reg->val & 0xff); 57 return 0; 58 } 59 #endif 60 61 /* ----------------------------------------------------------------------- */ 62 63 static const struct v4l2_subdev_core_ops cs3308_core_ops = { 64 #ifdef CONFIG_VIDEO_ADV_DEBUG 65 .g_register = cs3308_g_register, 66 .s_register = cs3308_s_register, 67 #endif 68 }; 69 70 static const struct v4l2_subdev_ops cs3308_ops = { 71 .core = &cs3308_core_ops, 72 }; 73 74 /* ----------------------------------------------------------------------- */ 75 76 static int cs3308_probe(struct i2c_client *client, 77 const struct i2c_device_id *id) 78 { 79 struct v4l2_subdev *sd; 80 unsigned i; 81 82 /* Check if the adapter supports the needed features */ 83 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA)) 84 return -EIO; 85 86 if ((i2c_smbus_read_byte_data(client, 0x1c) & 0xf0) != 0xe0) 87 return -ENODEV; 88 89 v4l_info(client, "chip found @ 0x%x (%s)\n", 90 client->addr << 1, client->adapter->name); 91 92 sd = kzalloc(sizeof(struct v4l2_subdev), GFP_KERNEL); 93 if (sd == NULL) 94 return -ENOMEM; 95 96 v4l2_i2c_subdev_init(sd, client, &cs3308_ops); 97 98 /* Set some reasonable defaults */ 99 cs3308_write(sd, 0x0d, 0x00); /* Power up all channels */ 100 cs3308_write(sd, 0x0e, 0x00); /* Master Power */ 101 cs3308_write(sd, 0x0b, 0x00); /* Device Configuration */ 102 /* Set volume for each channel */ 103 for (i = 1; i <= 8; i++) 104 cs3308_write(sd, i, 0xd2); 105 cs3308_write(sd, 0x0a, 0x00); /* Unmute all channels */ 106 return 0; 107 } 108 109 /* ----------------------------------------------------------------------- */ 110 111 static int cs3308_remove(struct i2c_client *client) 112 { 113 struct v4l2_subdev *sd = i2c_get_clientdata(client); 114 115 v4l2_device_unregister_subdev(sd); 116 kfree(sd); 117 return 0; 118 } 119 120 /* ----------------------------------------------------------------------- */ 121 122 static const struct i2c_device_id cs3308_id[] = { 123 { "cs3308", 0 }, 124 { } 125 }; 126 MODULE_DEVICE_TABLE(i2c, cs3308_id); 127 128 static struct i2c_driver cs3308_driver = { 129 .driver = { 130 .owner = THIS_MODULE, 131 .name = "cs3308", 132 }, 133 .probe = cs3308_probe, 134 .remove = cs3308_remove, 135 .id_table = cs3308_id, 136 }; 137 138 module_i2c_driver(cs3308_driver); 139