diff options
Diffstat (limited to 'drivers/media/i2c/tea6420.c')
| -rw-r--r-- | drivers/media/i2c/tea6420.c | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/drivers/media/i2c/tea6420.c b/drivers/media/i2c/tea6420.c new file mode 100644 index 0000000000..63f23784bb --- /dev/null +++ b/drivers/media/i2c/tea6420.c @@ -0,0 +1,140 @@ +// SPDX-License-Identifier: GPL-2.0-or-later + /* + tea6420 - i2c-driver for the tea6420 by SGS Thomson + + Copyright (C) 1998-2003 Michael Hunold <michael@mihu.de> + Copyright (C) 2008 Hans Verkuil <hverkuil@xs4all.nl> + + The tea6420 is a bus controlled audio-matrix with 5 stereo inputs, + 4 stereo outputs and gain control for each output. + It is cascadable, i.e. it can be found at the addresses 0x98 + and 0x9a on the i2c-bus. + + For detailed information download the specifications directly + from SGS Thomson at http://www.st.com + + */ + + +#include <linux/module.h> +#include <linux/ioctl.h> +#include <linux/slab.h> +#include <linux/i2c.h> +#include <media/v4l2-device.h> +#include "tea6420.h" + +MODULE_AUTHOR("Michael Hunold <michael@mihu.de>"); +MODULE_DESCRIPTION("tea6420 driver"); +MODULE_LICENSE("GPL"); + +static int debug; +module_param(debug, int, 0644); + +MODULE_PARM_DESC(debug, "Debug level (0-1)"); + + +/* make a connection between the input 'i' and the output 'o' + with gain 'g' (note: i = 6 means 'mute') */ +static int tea6420_s_routing(struct v4l2_subdev *sd, + u32 i, u32 o, u32 config) +{ + struct i2c_client *client = v4l2_get_subdevdata(sd); + int g = (o >> 4) & 0xf; + u8 byte; + int ret; + + o &= 0xf; + v4l2_dbg(1, debug, sd, "i=%d, o=%d, g=%d\n", i, o, g); + + /* check if the parameters are valid */ + if (i < 1 || i > 6 || o < 1 || o > 4 || g < 0 || g > 6 || g % 2 != 0) + return -EINVAL; + + byte = ((o - 1) << 5); + byte |= (i - 1); + + /* to understand this, have a look at the tea6420-specs (p.5) */ + switch (g) { + case 0: + byte |= (3 << 3); + break; + case 2: + byte |= (2 << 3); + break; + case 4: + byte |= (1 << 3); + break; + case 6: + break; + } + + ret = i2c_smbus_write_byte(client, byte); + if (ret) { + v4l2_dbg(1, debug, sd, + "i2c_smbus_write_byte() failed, ret:%d\n", ret); + return -EIO; + } + return 0; +} + +/* ----------------------------------------------------------------------- */ + +static const struct v4l2_subdev_audio_ops tea6420_audio_ops = { + .s_routing = tea6420_s_routing, +}; + +static const struct v4l2_subdev_ops tea6420_ops = { + .audio = &tea6420_audio_ops, +}; + +static int tea6420_probe(struct i2c_client *client) +{ + struct v4l2_subdev *sd; + int err, i; + + /* let's see whether this adapter can support what we need */ + if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WRITE_BYTE)) + return -EIO; + + v4l_info(client, "chip found @ 0x%x (%s)\n", + client->addr << 1, client->adapter->name); + + sd = devm_kzalloc(&client->dev, sizeof(*sd), GFP_KERNEL); + if (sd == NULL) + return -ENOMEM; + v4l2_i2c_subdev_init(sd, client, &tea6420_ops); + + /* set initial values: set "mute"-input to all outputs at gain 0 */ + err = 0; + for (i = 1; i < 5; i++) + err += tea6420_s_routing(sd, 6, i, 0); + if (err) { + v4l_dbg(1, debug, client, "could not initialize tea6420\n"); + return -ENODEV; + } + return 0; +} + +static void tea6420_remove(struct i2c_client *client) +{ + struct v4l2_subdev *sd = i2c_get_clientdata(client); + + v4l2_device_unregister_subdev(sd); +} + +static const struct i2c_device_id tea6420_id[] = { + { "tea6420", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, tea6420_id); + +static struct i2c_driver tea6420_driver = { + .driver = { + .name = "tea6420", + }, + .probe = tea6420_probe, + .remove = tea6420_remove, + .id_table = tea6420_id, +}; + +module_i2c_driver(tea6420_driver); |