1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 tea6420 - i2c-driver for the tea6420 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 tea6420 is a bus controlled audio-matrix with 5 stereo inputs, 9 4 stereo outputs and gain control for each output. 10 It is cascadable, i.e. it can be found at the addresses 0x98 11 and 0x9a on the i2c-bus. 12 13 For detailed information download the specifications directly 14 from SGS Thomson at http://www.st.com 15 16 */ 17 18 19 #include <linux/module.h> 20 #include <linux/ioctl.h> 21 #include <linux/slab.h> 22 #include <linux/i2c.h> 23 #include <media/v4l2-device.h> 24 #include "tea6420.h" 25 26 MODULE_AUTHOR("Michael Hunold <michael@mihu.de>"); 27 MODULE_DESCRIPTION("tea6420 driver"); 28 MODULE_LICENSE("GPL"); 29 30 static int debug; 31 module_param(debug, int, 0644); 32 33 MODULE_PARM_DESC(debug, "Debug level (0-1)"); 34 35 36 /* make a connection between the input 'i' and the output 'o' 37 with gain 'g' (note: i = 6 means 'mute') */ 38 static int tea6420_s_routing(struct v4l2_subdev *sd, 39 u32 i, u32 o, u32 config) 40 { 41 struct i2c_client *client = v4l2_get_subdevdata(sd); 42 int g = (o >> 4) & 0xf; 43 u8 byte; 44 int ret; 45 46 o &= 0xf; 47 v4l2_dbg(1, debug, sd, "i=%d, o=%d, g=%d\n", i, o, g); 48 49 /* check if the parameters are valid */ 50 if (i < 1 || i > 6 || o < 1 || o > 4 || g < 0 || g > 6 || g % 2 != 0) 51 return -EINVAL; 52 53 byte = ((o - 1) << 5); 54 byte |= (i - 1); 55 56 /* to understand this, have a look at the tea6420-specs (p.5) */ 57 switch (g) { 58 case 0: 59 byte |= (3 << 3); 60 break; 61 case 2: 62 byte |= (2 << 3); 63 break; 64 case 4: 65 byte |= (1 << 3); 66 break; 67 case 6: 68 break; 69 } 70 71 ret = i2c_smbus_write_byte(client, byte); 72 if (ret) { 73 v4l2_dbg(1, debug, sd, 74 "i2c_smbus_write_byte() failed, ret:%d\n", ret); 75 return -EIO; 76 } 77 return 0; 78 } 79 80 /* ----------------------------------------------------------------------- */ 81 82 static const struct v4l2_subdev_audio_ops tea6420_audio_ops = { 83 .s_routing = tea6420_s_routing, 84 }; 85 86 static const struct v4l2_subdev_ops tea6420_ops = { 87 .audio = &tea6420_audio_ops, 88 }; 89 90 static int tea6420_probe(struct i2c_client *client, 91 const struct i2c_device_id *id) 92 { 93 struct v4l2_subdev *sd; 94 int err, i; 95 96 /* let's see whether this adapter can support what we need */ 97 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WRITE_BYTE)) 98 return -EIO; 99 100 v4l_info(client, "chip found @ 0x%x (%s)\n", 101 client->addr << 1, client->adapter->name); 102 103 sd = devm_kzalloc(&client->dev, sizeof(*sd), GFP_KERNEL); 104 if (sd == NULL) 105 return -ENOMEM; 106 v4l2_i2c_subdev_init(sd, client, &tea6420_ops); 107 108 /* set initial values: set "mute"-input to all outputs at gain 0 */ 109 err = 0; 110 for (i = 1; i < 5; i++) 111 err += tea6420_s_routing(sd, 6, i, 0); 112 if (err) { 113 v4l_dbg(1, debug, client, "could not initialize tea6420\n"); 114 return -ENODEV; 115 } 116 return 0; 117 } 118 119 static void tea6420_remove(struct i2c_client *client) 120 { 121 struct v4l2_subdev *sd = i2c_get_clientdata(client); 122 123 v4l2_device_unregister_subdev(sd); 124 } 125 126 static const struct i2c_device_id tea6420_id[] = { 127 { "tea6420", 0 }, 128 { } 129 }; 130 MODULE_DEVICE_TABLE(i2c, tea6420_id); 131 132 static struct i2c_driver tea6420_driver = { 133 .driver = { 134 .name = "tea6420", 135 }, 136 .probe = tea6420_probe, 137 .remove = tea6420_remove, 138 .id_table = tea6420_id, 139 }; 140 141 module_i2c_driver(tea6420_driver); 142