linux/drivers/iio/amplifiers/ad8366.c
Javier Martinez Canillas ed199a11bd iio: Export SPI module alias information in missing drivers
The SPI core always reports the MODALIAS uevent as "spi:<modalias>"
regardless of the mechanism that was used to register the device
(i.e: OF or board code) and the table that is used later to match
the driver with the device (i.e: SPI id table or OF match table).

So drivers needs to export the SPI id table and this be built into
the module or udev won't have the necessary information to autoload
the needed driver module when the device is added.

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2015-08-22 19:07:09 +01:00

215 lines
4.4 KiB
C

/*
* AD8366 SPI Dual-Digital Variable Gain Amplifier (VGA)
*
* Copyright 2012 Analog Devices Inc.
*
* Licensed under the GPL-2.
*/
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/spi/spi.h>
#include <linux/regulator/consumer.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/bitrev.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
struct ad8366_state {
struct spi_device *spi;
struct regulator *reg;
unsigned char ch[2];
/*
* DMA (thus cache coherency maintenance) requires the
* transfer buffers to live in their own cache lines.
*/
unsigned char data[2] ____cacheline_aligned;
};
static int ad8366_write(struct iio_dev *indio_dev,
unsigned char ch_a, unsigned char ch_b)
{
struct ad8366_state *st = iio_priv(indio_dev);
int ret;
ch_a = bitrev8(ch_a & 0x3F);
ch_b = bitrev8(ch_b & 0x3F);
st->data[0] = ch_b >> 4;
st->data[1] = (ch_b << 4) | (ch_a >> 2);
ret = spi_write(st->spi, st->data, ARRAY_SIZE(st->data));
if (ret < 0)
dev_err(&indio_dev->dev, "write failed (%d)", ret);
return ret;
}
static int ad8366_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val,
int *val2,
long m)
{
struct ad8366_state *st = iio_priv(indio_dev);
int ret;
unsigned code;
mutex_lock(&indio_dev->mlock);
switch (m) {
case IIO_CHAN_INFO_HARDWAREGAIN:
code = st->ch[chan->channel];
/* Values in dB */
code = code * 253 + 4500;
*val = code / 1000;
*val2 = (code % 1000) * 1000;
ret = IIO_VAL_INT_PLUS_MICRO_DB;
break;
default:
ret = -EINVAL;
}
mutex_unlock(&indio_dev->mlock);
return ret;
};
static int ad8366_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val,
int val2,
long mask)
{
struct ad8366_state *st = iio_priv(indio_dev);
unsigned code;
int ret;
if (val < 0 || val2 < 0)
return -EINVAL;
/* Values in dB */
code = (((u8)val * 1000) + ((u32)val2 / 1000));
if (code > 20500 || code < 4500)
return -EINVAL;
code = (code - 4500) / 253;
mutex_lock(&indio_dev->mlock);
switch (mask) {
case IIO_CHAN_INFO_HARDWAREGAIN:
st->ch[chan->channel] = code;
ret = ad8366_write(indio_dev, st->ch[0], st->ch[1]);
break;
default:
ret = -EINVAL;
}
mutex_unlock(&indio_dev->mlock);
return ret;
}
static const struct iio_info ad8366_info = {
.read_raw = &ad8366_read_raw,
.write_raw = &ad8366_write_raw,
.driver_module = THIS_MODULE,
};
#define AD8366_CHAN(_channel) { \
.type = IIO_VOLTAGE, \
.output = 1, \
.indexed = 1, \
.channel = _channel, \
.info_mask_separate = BIT(IIO_CHAN_INFO_HARDWAREGAIN),\
}
static const struct iio_chan_spec ad8366_channels[] = {
AD8366_CHAN(0),
AD8366_CHAN(1),
};
static int ad8366_probe(struct spi_device *spi)
{
struct iio_dev *indio_dev;
struct ad8366_state *st;
int ret;
indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
if (indio_dev == NULL)
return -ENOMEM;
st = iio_priv(indio_dev);
st->reg = devm_regulator_get(&spi->dev, "vcc");
if (!IS_ERR(st->reg)) {
ret = regulator_enable(st->reg);
if (ret)
return ret;
}
spi_set_drvdata(spi, indio_dev);
st->spi = spi;
indio_dev->dev.parent = &spi->dev;
indio_dev->name = spi_get_device_id(spi)->name;
indio_dev->info = &ad8366_info;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = ad8366_channels;
indio_dev->num_channels = ARRAY_SIZE(ad8366_channels);
ret = iio_device_register(indio_dev);
if (ret)
goto error_disable_reg;
ad8366_write(indio_dev, 0, 0);
return 0;
error_disable_reg:
if (!IS_ERR(st->reg))
regulator_disable(st->reg);
return ret;
}
static int ad8366_remove(struct spi_device *spi)
{
struct iio_dev *indio_dev = spi_get_drvdata(spi);
struct ad8366_state *st = iio_priv(indio_dev);
struct regulator *reg = st->reg;
iio_device_unregister(indio_dev);
if (!IS_ERR(reg))
regulator_disable(reg);
return 0;
}
static const struct spi_device_id ad8366_id[] = {
{"ad8366", 0},
{}
};
MODULE_DEVICE_TABLE(spi, ad8366_id);
static struct spi_driver ad8366_driver = {
.driver = {
.name = KBUILD_MODNAME,
.owner = THIS_MODULE,
},
.probe = ad8366_probe,
.remove = ad8366_remove,
.id_table = ad8366_id,
};
module_spi_driver(ad8366_driver);
MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
MODULE_DESCRIPTION("Analog Devices AD8366 VGA");
MODULE_LICENSE("GPL v2");