linux/drivers/iio/dac/ad5761.c
Uwe Kleine-König a0386bba70
spi: make remove callback a void function
The value returned by an spi driver's remove function is mostly ignored.
(Only an error message is printed if the value is non-zero that the
error is ignored.)

So change the prototype of the remove function to return no value. This
way driver authors are not tempted to assume that passing an error to
the upper layer is a good idea. All drivers are adapted accordingly.
There is no intended change of behaviour, all callbacks were prepared to
return 0 before.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Acked-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Claudius Heine <ch@denx.de>
Acked-by: Stefan Schmidt <stefan@datenfreihafen.org>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # For MMC
Acked-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Acked-by: Łukasz Stelmach <l.stelmach@samsung.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20220123175201.34839-6-u.kleine-koenig@pengutronix.de
Signed-off-by: Mark Brown <broonie@kernel.org>
2022-02-09 13:00:45 +00:00

430 lines
9.2 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* AD5721, AD5721R, AD5761, AD5761R, Voltage Output Digital to Analog Converter
*
* Copyright 2016 Qtechnology A/S
* 2016 Ricardo Ribalda <ribalda@kernel.org>
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/spi/spi.h>
#include <linux/bitops.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/regulator/consumer.h>
#include <linux/platform_data/ad5761.h>
#define AD5761_ADDR(addr) ((addr & 0xf) << 16)
#define AD5761_ADDR_NOOP 0x0
#define AD5761_ADDR_DAC_WRITE 0x3
#define AD5761_ADDR_CTRL_WRITE_REG 0x4
#define AD5761_ADDR_SW_DATA_RESET 0x7
#define AD5761_ADDR_DAC_READ 0xb
#define AD5761_ADDR_CTRL_READ_REG 0xc
#define AD5761_ADDR_SW_FULL_RESET 0xf
#define AD5761_CTRL_USE_INTVREF BIT(5)
#define AD5761_CTRL_ETS BIT(6)
/**
* struct ad5761_chip_info - chip specific information
* @int_vref: Value of the internal reference voltage in mV - 0 if external
* reference voltage is used
* @channel: channel specification
*/
struct ad5761_chip_info {
unsigned long int_vref;
const struct iio_chan_spec channel;
};
struct ad5761_range_params {
int m;
int c;
};
enum ad5761_supported_device_ids {
ID_AD5721,
ID_AD5721R,
ID_AD5761,
ID_AD5761R,
};
/**
* struct ad5761_state - driver instance specific data
* @spi: spi_device
* @vref_reg: reference voltage regulator
* @use_intref: true when the internal voltage reference is used
* @vref: actual voltage reference in mVolts
* @range: output range mode used
* @lock: lock to protect the data buffer during SPI ops
* @data: cache aligned spi buffer
*/
struct ad5761_state {
struct spi_device *spi;
struct regulator *vref_reg;
struct mutex lock;
bool use_intref;
int vref;
enum ad5761_voltage_range range;
/*
* DMA (thus cache coherency maintenance) requires the
* transfer buffers to live in their own cache lines.
*/
union {
__be32 d32;
u8 d8[4];
} data[3] ____cacheline_aligned;
};
static const struct ad5761_range_params ad5761_range_params[] = {
[AD5761_VOLTAGE_RANGE_M10V_10V] = {
.m = 80,
.c = 40,
},
[AD5761_VOLTAGE_RANGE_0V_10V] = {
.m = 40,
.c = 0,
},
[AD5761_VOLTAGE_RANGE_M5V_5V] = {
.m = 40,
.c = 20,
},
[AD5761_VOLTAGE_RANGE_0V_5V] = {
.m = 20,
.c = 0,
},
[AD5761_VOLTAGE_RANGE_M2V5_7V5] = {
.m = 40,
.c = 10,
},
[AD5761_VOLTAGE_RANGE_M3V_3V] = {
.m = 24,
.c = 12,
},
[AD5761_VOLTAGE_RANGE_0V_16V] = {
.m = 64,
.c = 0,
},
[AD5761_VOLTAGE_RANGE_0V_20V] = {
.m = 80,
.c = 0,
},
};
static int _ad5761_spi_write(struct ad5761_state *st, u8 addr, u16 val)
{
st->data[0].d32 = cpu_to_be32(AD5761_ADDR(addr) | val);
return spi_write(st->spi, &st->data[0].d8[1], 3);
}
static int ad5761_spi_write(struct iio_dev *indio_dev, u8 addr, u16 val)
{
struct ad5761_state *st = iio_priv(indio_dev);
int ret;
mutex_lock(&st->lock);
ret = _ad5761_spi_write(st, addr, val);
mutex_unlock(&st->lock);
return ret;
}
static int _ad5761_spi_read(struct ad5761_state *st, u8 addr, u16 *val)
{
int ret;
struct spi_transfer xfers[] = {
{
.tx_buf = &st->data[0].d8[1],
.bits_per_word = 8,
.len = 3,
.cs_change = true,
}, {
.tx_buf = &st->data[1].d8[1],
.rx_buf = &st->data[2].d8[1],
.bits_per_word = 8,
.len = 3,
},
};
st->data[0].d32 = cpu_to_be32(AD5761_ADDR(addr));
st->data[1].d32 = cpu_to_be32(AD5761_ADDR(AD5761_ADDR_NOOP));
ret = spi_sync_transfer(st->spi, xfers, ARRAY_SIZE(xfers));
*val = be32_to_cpu(st->data[2].d32);
return ret;
}
static int ad5761_spi_read(struct iio_dev *indio_dev, u8 addr, u16 *val)
{
struct ad5761_state *st = iio_priv(indio_dev);
int ret;
mutex_lock(&st->lock);
ret = _ad5761_spi_read(st, addr, val);
mutex_unlock(&st->lock);
return ret;
}
static int ad5761_spi_set_range(struct ad5761_state *st,
enum ad5761_voltage_range range)
{
u16 aux;
int ret;
aux = (range & 0x7) | AD5761_CTRL_ETS;
if (st->use_intref)
aux |= AD5761_CTRL_USE_INTVREF;
ret = _ad5761_spi_write(st, AD5761_ADDR_SW_FULL_RESET, 0);
if (ret)
return ret;
ret = _ad5761_spi_write(st, AD5761_ADDR_CTRL_WRITE_REG, aux);
if (ret)
return ret;
st->range = range;
return 0;
}
static int ad5761_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val,
int *val2,
long mask)
{
struct ad5761_state *st;
int ret;
u16 aux;
switch (mask) {
case IIO_CHAN_INFO_RAW:
ret = ad5761_spi_read(indio_dev, AD5761_ADDR_DAC_READ, &aux);
if (ret)
return ret;
*val = aux >> chan->scan_type.shift;
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
st = iio_priv(indio_dev);
*val = st->vref * ad5761_range_params[st->range].m;
*val /= 10;
*val2 = chan->scan_type.realbits;
return IIO_VAL_FRACTIONAL_LOG2;
case IIO_CHAN_INFO_OFFSET:
st = iio_priv(indio_dev);
*val = -(1 << chan->scan_type.realbits);
*val *= ad5761_range_params[st->range].c;
*val /= ad5761_range_params[st->range].m;
return IIO_VAL_INT;
default:
return -EINVAL;
}
}
static int ad5761_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val,
int val2,
long mask)
{
u16 aux;
if (mask != IIO_CHAN_INFO_RAW)
return -EINVAL;
if (val2 || (val << chan->scan_type.shift) > 0xffff || val < 0)
return -EINVAL;
aux = val << chan->scan_type.shift;
return ad5761_spi_write(indio_dev, AD5761_ADDR_DAC_WRITE, aux);
}
static const struct iio_info ad5761_info = {
.read_raw = &ad5761_read_raw,
.write_raw = &ad5761_write_raw,
};
#define AD5761_CHAN(_bits) { \
.type = IIO_VOLTAGE, \
.output = 1, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \
BIT(IIO_CHAN_INFO_OFFSET), \
.scan_type = { \
.sign = 'u', \
.realbits = (_bits), \
.storagebits = 16, \
.shift = 16 - (_bits), \
}, \
}
static const struct ad5761_chip_info ad5761_chip_infos[] = {
[ID_AD5721] = {
.int_vref = 0,
.channel = AD5761_CHAN(12),
},
[ID_AD5721R] = {
.int_vref = 2500,
.channel = AD5761_CHAN(12),
},
[ID_AD5761] = {
.int_vref = 0,
.channel = AD5761_CHAN(16),
},
[ID_AD5761R] = {
.int_vref = 2500,
.channel = AD5761_CHAN(16),
},
};
static int ad5761_get_vref(struct ad5761_state *st,
const struct ad5761_chip_info *chip_info)
{
int ret;
st->vref_reg = devm_regulator_get_optional(&st->spi->dev, "vref");
if (PTR_ERR(st->vref_reg) == -ENODEV) {
/* Use Internal regulator */
if (!chip_info->int_vref) {
dev_err(&st->spi->dev,
"Voltage reference not found\n");
return -EIO;
}
st->use_intref = true;
st->vref = chip_info->int_vref;
return 0;
}
if (IS_ERR(st->vref_reg)) {
dev_err(&st->spi->dev,
"Error getting voltage reference regulator\n");
return PTR_ERR(st->vref_reg);
}
ret = regulator_enable(st->vref_reg);
if (ret) {
dev_err(&st->spi->dev,
"Failed to enable voltage reference\n");
return ret;
}
ret = regulator_get_voltage(st->vref_reg);
if (ret < 0) {
dev_err(&st->spi->dev,
"Failed to get voltage reference value\n");
goto disable_regulator_vref;
}
if (ret < 2000000 || ret > 3000000) {
dev_warn(&st->spi->dev,
"Invalid external voltage ref. value %d uV\n", ret);
ret = -EIO;
goto disable_regulator_vref;
}
st->vref = ret / 1000;
st->use_intref = false;
return 0;
disable_regulator_vref:
regulator_disable(st->vref_reg);
st->vref_reg = NULL;
return ret;
}
static int ad5761_probe(struct spi_device *spi)
{
struct iio_dev *iio_dev;
struct ad5761_state *st;
int ret;
const struct ad5761_chip_info *chip_info =
&ad5761_chip_infos[spi_get_device_id(spi)->driver_data];
enum ad5761_voltage_range voltage_range = AD5761_VOLTAGE_RANGE_0V_5V;
struct ad5761_platform_data *pdata = dev_get_platdata(&spi->dev);
iio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
if (!iio_dev)
return -ENOMEM;
st = iio_priv(iio_dev);
st->spi = spi;
spi_set_drvdata(spi, iio_dev);
ret = ad5761_get_vref(st, chip_info);
if (ret)
return ret;
if (pdata)
voltage_range = pdata->voltage_range;
mutex_init(&st->lock);
ret = ad5761_spi_set_range(st, voltage_range);
if (ret)
goto disable_regulator_err;
iio_dev->info = &ad5761_info;
iio_dev->modes = INDIO_DIRECT_MODE;
iio_dev->channels = &chip_info->channel;
iio_dev->num_channels = 1;
iio_dev->name = spi_get_device_id(st->spi)->name;
ret = iio_device_register(iio_dev);
if (ret)
goto disable_regulator_err;
return 0;
disable_regulator_err:
if (!IS_ERR_OR_NULL(st->vref_reg))
regulator_disable(st->vref_reg);
return ret;
}
static void ad5761_remove(struct spi_device *spi)
{
struct iio_dev *iio_dev = spi_get_drvdata(spi);
struct ad5761_state *st = iio_priv(iio_dev);
iio_device_unregister(iio_dev);
if (!IS_ERR_OR_NULL(st->vref_reg))
regulator_disable(st->vref_reg);
}
static const struct spi_device_id ad5761_id[] = {
{"ad5721", ID_AD5721},
{"ad5721r", ID_AD5721R},
{"ad5761", ID_AD5761},
{"ad5761r", ID_AD5761R},
{}
};
MODULE_DEVICE_TABLE(spi, ad5761_id);
static struct spi_driver ad5761_driver = {
.driver = {
.name = "ad5761",
},
.probe = ad5761_probe,
.remove = ad5761_remove,
.id_table = ad5761_id,
};
module_spi_driver(ad5761_driver);
MODULE_AUTHOR("Ricardo Ribalda <ribalda@kernel.org>");
MODULE_DESCRIPTION("Analog Devices AD5721, AD5721R, AD5761, AD5761R driver");
MODULE_LICENSE("GPL v2");