1 /* 2 tea6420 - i2c-driver for the tea6420 by SGS Thomson 3 4 Copyright (C) 1998-2003 Michael Hunold <michael@mihu.de> 5 Copyright (C) 2008 Hans Verkuil <hverkuil@xs4all.nl> 6 7 The tea6420 is a bus controlled audio-matrix with 5 stereo inputs, 8 4 stereo outputs and gain control for each output. 9 It is cascadable, i.e. it can be found at the addresses 0x98 10 and 0x9a on the i2c-bus. 11 12 For detailed informations download the specifications directly 13 from SGS Thomson at http://www.st.com 14 15 This program is free software; you can redistribute it and/or modify 16 it under the terms of the GNU General Public License as published by 17 the Free Software Foundation; either version 2 of the License, or 18 (at your option) any later version. 19 20 This program is distributed in the hope that it will be useful, 21 but WITHOUT ANY WARRANTY; without even the implied warranty of 22 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 23 GNU General Public License for more details. 24 25 You should have received a copy of the GNU General Public License 26 along with this program; if not, write to the Free Software 27 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 28 */ 29 30 31 #include <linux/module.h> 32 #include <linux/ioctl.h> 33 #include <linux/slab.h> 34 #include <linux/i2c.h> 35 #include <media/v4l2-device.h> 36 #include "tea6420.h" 37 38 MODULE_AUTHOR("Michael Hunold <michael@mihu.de>"); 39 MODULE_DESCRIPTION("tea6420 driver"); 40 MODULE_LICENSE("GPL"); 41 42 static int debug; 43 module_param(debug, int, 0644); 44 45 MODULE_PARM_DESC(debug, "Debug level (0-1)"); 46 47 48 /* make a connection between the input 'i' and the output 'o' 49 with gain 'g' (note: i = 6 means 'mute') */ 50 static int tea6420_s_routing(struct v4l2_subdev *sd, 51 u32 i, u32 o, u32 config) 52 { 53 struct i2c_client *client = v4l2_get_subdevdata(sd); 54 int g = (o >> 4) & 0xf; 55 u8 byte; 56 int ret; 57 58 o &= 0xf; 59 v4l2_dbg(1, debug, sd, "i=%d, o=%d, g=%d\n", i, o, g); 60 61 /* check if the parameters are valid */ 62 if (i < 1 || i > 6 || o < 1 || o > 4 || g < 0 || g > 6 || g % 2 != 0) 63 return -EINVAL; 64 65 byte = ((o - 1) << 5); 66 byte |= (i - 1); 67 68 /* to understand this, have a look at the tea6420-specs (p.5) */ 69 switch (g) { 70 case 0: 71 byte |= (3 << 3); 72 break; 73 case 2: 74 byte |= (2 << 3); 75 break; 76 case 4: 77 byte |= (1 << 3); 78 break; 79 case 6: 80 break; 81 } 82 83 ret = i2c_smbus_write_byte(client, byte); 84 if (ret) { 85 v4l2_dbg(1, debug, sd, 86 "i2c_smbus_write_byte() failed, ret:%d\n", ret); 87 return -EIO; 88 } 89 return 0; 90 } 91 92 /* ----------------------------------------------------------------------- */ 93 94 static const struct v4l2_subdev_audio_ops tea6420_audio_ops = { 95 .s_routing = tea6420_s_routing, 96 }; 97 98 static const struct v4l2_subdev_ops tea6420_ops = { 99 .audio = &tea6420_audio_ops, 100 }; 101 102 static int tea6420_probe(struct i2c_client *client, 103 const struct i2c_device_id *id) 104 { 105 struct v4l2_subdev *sd; 106 int err, i; 107 108 /* let's see whether this adapter can support what we need */ 109 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WRITE_BYTE)) 110 return -EIO; 111 112 v4l_info(client, "chip found @ 0x%x (%s)\n", 113 client->addr << 1, client->adapter->name); 114 115 sd = devm_kzalloc(&client->dev, sizeof(*sd), GFP_KERNEL); 116 if (sd == NULL) 117 return -ENOMEM; 118 v4l2_i2c_subdev_init(sd, client, &tea6420_ops); 119 120 /* set initial values: set "mute"-input to all outputs at gain 0 */ 121 err = 0; 122 for (i = 1; i < 5; i++) 123 err += tea6420_s_routing(sd, 6, i, 0); 124 if (err) { 125 v4l_dbg(1, debug, client, "could not initialize tea6420\n"); 126 return -ENODEV; 127 } 128 return 0; 129 } 130 131 static int tea6420_remove(struct i2c_client *client) 132 { 133 struct v4l2_subdev *sd = i2c_get_clientdata(client); 134 135 v4l2_device_unregister_subdev(sd); 136 return 0; 137 } 138 139 static const struct i2c_device_id tea6420_id[] = { 140 { "tea6420", 0 }, 141 { } 142 }; 143 MODULE_DEVICE_TABLE(i2c, tea6420_id); 144 145 static struct i2c_driver tea6420_driver = { 146 .driver = { 147 .name = "tea6420", 148 }, 149 .probe = tea6420_probe, 150 .remove = tea6420_remove, 151 .id_table = tea6420_id, 152 }; 153 154 module_i2c_driver(tea6420_driver); 155