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linux/drivers/iio/dac/ltc2632.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

483 lines
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// SPDX-License-Identifier: GPL-2.0-only
/*
* LTC2632 Digital to analog convertors spi driver
*
* Copyright 2017 Maxime Roussin-Bélanger
* expanded by Silvan Murer <silvan.murer@gmail.com>
*/
#include <linux/device.h>
#include <linux/spi/spi.h>
#include <linux/module.h>
#include <linux/iio/iio.h>
#include <linux/regulator/consumer.h>
#include <asm/unaligned.h>
#define LTC2632_CMD_WRITE_INPUT_N 0x0
#define LTC2632_CMD_UPDATE_DAC_N 0x1
#define LTC2632_CMD_WRITE_INPUT_N_UPDATE_ALL 0x2
#define LTC2632_CMD_WRITE_INPUT_N_UPDATE_N 0x3
#define LTC2632_CMD_POWERDOWN_DAC_N 0x4
#define LTC2632_CMD_POWERDOWN_CHIP 0x5
#define LTC2632_CMD_INTERNAL_REFER 0x6
#define LTC2632_CMD_EXTERNAL_REFER 0x7
/**
* struct ltc2632_chip_info - chip specific information
* @channels: channel spec for the DAC
* @num_channels: DAC channel count of the chip
* @vref_mv: internal reference voltage
*/
struct ltc2632_chip_info {
const struct iio_chan_spec *channels;
const size_t num_channels;
const int vref_mv;
};
/**
* struct ltc2632_state - driver instance specific data
* @spi_dev: pointer to the spi_device struct
* @powerdown_cache_mask: used to show current channel powerdown state
* @vref_mv: used reference voltage (internal or external)
* @vref_reg: regulator for the reference voltage
*/
struct ltc2632_state {
struct spi_device *spi_dev;
unsigned int powerdown_cache_mask;
int vref_mv;
struct regulator *vref_reg;
};
enum ltc2632_supported_device_ids {
ID_LTC2632L12,
ID_LTC2632L10,
ID_LTC2632L8,
ID_LTC2632H12,
ID_LTC2632H10,
ID_LTC2632H8,
ID_LTC2634L12,
ID_LTC2634L10,
ID_LTC2634L8,
ID_LTC2634H12,
ID_LTC2634H10,
ID_LTC2634H8,
ID_LTC2636L12,
ID_LTC2636L10,
ID_LTC2636L8,
ID_LTC2636H12,
ID_LTC2636H10,
ID_LTC2636H8,
};
static int ltc2632_spi_write(struct spi_device *spi,
u8 cmd, u8 addr, u16 val, u8 shift)
{
u32 data;
u8 msg[3];
/*
* The input shift register is 24 bits wide.
* The next four are the command bits, C3 to C0,
* followed by the 4-bit DAC address, A3 to A0, and then the
* 12-, 10-, 8-bit data-word. The data-word comprises the 12-,
* 10-, 8-bit input code followed by 4, 6, or 8 don't care bits.
*/
data = (cmd << 20) | (addr << 16) | (val << shift);
put_unaligned_be24(data, &msg[0]);
return spi_write(spi, msg, sizeof(msg));
}
static int ltc2632_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val,
int *val2,
long m)
{
const struct ltc2632_state *st = iio_priv(indio_dev);
switch (m) {
case IIO_CHAN_INFO_SCALE:
*val = st->vref_mv;
*val2 = chan->scan_type.realbits;
return IIO_VAL_FRACTIONAL_LOG2;
}
return -EINVAL;
}
static int ltc2632_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val,
int val2,
long mask)
{
struct ltc2632_state *st = iio_priv(indio_dev);
switch (mask) {
case IIO_CHAN_INFO_RAW:
if (val >= (1 << chan->scan_type.realbits) || val < 0)
return -EINVAL;
return ltc2632_spi_write(st->spi_dev,
LTC2632_CMD_WRITE_INPUT_N_UPDATE_N,
chan->address, val,
chan->scan_type.shift);
default:
return -EINVAL;
}
}
static ssize_t ltc2632_read_dac_powerdown(struct iio_dev *indio_dev,
uintptr_t private,
const struct iio_chan_spec *chan,
char *buf)
{
struct ltc2632_state *st = iio_priv(indio_dev);
return sysfs_emit(buf, "%d\n",
!!(st->powerdown_cache_mask & (1 << chan->channel)));
}
static ssize_t ltc2632_write_dac_powerdown(struct iio_dev *indio_dev,
uintptr_t private,
const struct iio_chan_spec *chan,
const char *buf,
size_t len)
{
bool pwr_down;
int ret;
struct ltc2632_state *st = iio_priv(indio_dev);
ret = strtobool(buf, &pwr_down);
if (ret)
return ret;
if (pwr_down)
st->powerdown_cache_mask |= (1 << chan->channel);
else
st->powerdown_cache_mask &= ~(1 << chan->channel);
ret = ltc2632_spi_write(st->spi_dev,
LTC2632_CMD_POWERDOWN_DAC_N,
chan->channel, 0, 0);
return ret ? ret : len;
}
static const struct iio_info ltc2632_info = {
.write_raw = ltc2632_write_raw,
.read_raw = ltc2632_read_raw,
};
static const struct iio_chan_spec_ext_info ltc2632_ext_info[] = {
{
.name = "powerdown",
.read = ltc2632_read_dac_powerdown,
.write = ltc2632_write_dac_powerdown,
.shared = IIO_SEPARATE,
},
{ },
};
#define LTC2632_CHANNEL(_chan, _bits) { \
.type = IIO_VOLTAGE, \
.indexed = 1, \
.output = 1, \
.channel = (_chan), \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
.address = (_chan), \
.scan_type = { \
.realbits = (_bits), \
.shift = 16 - (_bits), \
}, \
.ext_info = ltc2632_ext_info, \
}
#define DECLARE_LTC2632_CHANNELS(_name, _bits) \
const struct iio_chan_spec _name ## _channels[] = { \
LTC2632_CHANNEL(0, _bits), \
LTC2632_CHANNEL(1, _bits), \
LTC2632_CHANNEL(2, _bits), \
LTC2632_CHANNEL(3, _bits), \
LTC2632_CHANNEL(4, _bits), \
LTC2632_CHANNEL(5, _bits), \
LTC2632_CHANNEL(6, _bits), \
LTC2632_CHANNEL(7, _bits), \
}
static DECLARE_LTC2632_CHANNELS(ltc2632x12, 12);
static DECLARE_LTC2632_CHANNELS(ltc2632x10, 10);
static DECLARE_LTC2632_CHANNELS(ltc2632x8, 8);
static const struct ltc2632_chip_info ltc2632_chip_info_tbl[] = {
[ID_LTC2632L12] = {
.channels = ltc2632x12_channels,
.num_channels = 2,
.vref_mv = 2500,
},
[ID_LTC2632L10] = {
.channels = ltc2632x10_channels,
.num_channels = 2,
.vref_mv = 2500,
},
[ID_LTC2632L8] = {
.channels = ltc2632x8_channels,
.num_channels = 2,
.vref_mv = 2500,
},
[ID_LTC2632H12] = {
.channels = ltc2632x12_channels,
.num_channels = 2,
.vref_mv = 4096,
},
[ID_LTC2632H10] = {
.channels = ltc2632x10_channels,
.num_channels = 2,
.vref_mv = 4096,
},
[ID_LTC2632H8] = {
.channels = ltc2632x8_channels,
.num_channels = 2,
.vref_mv = 4096,
},
[ID_LTC2634L12] = {
.channels = ltc2632x12_channels,
.num_channels = 4,
.vref_mv = 2500,
},
[ID_LTC2634L10] = {
.channels = ltc2632x10_channels,
.num_channels = 4,
.vref_mv = 2500,
},
[ID_LTC2634L8] = {
.channels = ltc2632x8_channels,
.num_channels = 4,
.vref_mv = 2500,
},
[ID_LTC2634H12] = {
.channels = ltc2632x12_channels,
.num_channels = 4,
.vref_mv = 4096,
},
[ID_LTC2634H10] = {
.channels = ltc2632x10_channels,
.num_channels = 4,
.vref_mv = 4096,
},
[ID_LTC2634H8] = {
.channels = ltc2632x8_channels,
.num_channels = 4,
.vref_mv = 4096,
},
[ID_LTC2636L12] = {
.channels = ltc2632x12_channels,
.num_channels = 8,
.vref_mv = 2500,
},
[ID_LTC2636L10] = {
.channels = ltc2632x10_channels,
.num_channels = 8,
.vref_mv = 2500,
},
[ID_LTC2636L8] = {
.channels = ltc2632x8_channels,
.num_channels = 8,
.vref_mv = 2500,
},
[ID_LTC2636H12] = {
.channels = ltc2632x12_channels,
.num_channels = 8,
.vref_mv = 4096,
},
[ID_LTC2636H10] = {
.channels = ltc2632x10_channels,
.num_channels = 8,
.vref_mv = 4096,
},
[ID_LTC2636H8] = {
.channels = ltc2632x8_channels,
.num_channels = 8,
.vref_mv = 4096,
},
};
static int ltc2632_probe(struct spi_device *spi)
{
struct ltc2632_state *st;
struct iio_dev *indio_dev;
struct ltc2632_chip_info *chip_info;
int ret;
indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
if (!indio_dev)
return -ENOMEM;
st = iio_priv(indio_dev);
spi_set_drvdata(spi, indio_dev);
st->spi_dev = spi;
chip_info = (struct ltc2632_chip_info *)
spi_get_device_id(spi)->driver_data;
st->vref_reg = devm_regulator_get_optional(&spi->dev, "vref");
if (PTR_ERR(st->vref_reg) == -ENODEV) {
/* use internal reference voltage */
st->vref_reg = NULL;
st->vref_mv = chip_info->vref_mv;
ret = ltc2632_spi_write(spi, LTC2632_CMD_INTERNAL_REFER,
0, 0, 0);
if (ret) {
dev_err(&spi->dev,
"Set internal reference command failed, %d\n",
ret);
return ret;
}
} else if (IS_ERR(st->vref_reg)) {
dev_err(&spi->dev,
"Error getting voltage reference regulator\n");
return PTR_ERR(st->vref_reg);
} else {
/* use external reference voltage */
ret = regulator_enable(st->vref_reg);
if (ret) {
dev_err(&spi->dev,
"enable reference regulator failed, %d\n",
ret);
return ret;
}
st->vref_mv = regulator_get_voltage(st->vref_reg) / 1000;
ret = ltc2632_spi_write(spi, LTC2632_CMD_EXTERNAL_REFER,
0, 0, 0);
if (ret) {
dev_err(&spi->dev,
"Set external reference command failed, %d\n",
ret);
return ret;
}
}
indio_dev->name = dev_of_node(&spi->dev) ? dev_of_node(&spi->dev)->name
: spi_get_device_id(spi)->name;
indio_dev->info = &ltc2632_info;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = chip_info->channels;
indio_dev->num_channels = chip_info->num_channels;
return iio_device_register(indio_dev);
}
static void ltc2632_remove(struct spi_device *spi)
{
struct iio_dev *indio_dev = spi_get_drvdata(spi);
struct ltc2632_state *st = iio_priv(indio_dev);
iio_device_unregister(indio_dev);
if (st->vref_reg)
regulator_disable(st->vref_reg);
}
static const struct spi_device_id ltc2632_id[] = {
{ "ltc2632-l12", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2632L12] },
{ "ltc2632-l10", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2632L10] },
{ "ltc2632-l8", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2632L8] },
{ "ltc2632-h12", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2632H12] },
{ "ltc2632-h10", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2632H10] },
{ "ltc2632-h8", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2632H8] },
{ "ltc2634-l12", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2634L12] },
{ "ltc2634-l10", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2634L10] },
{ "ltc2634-l8", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2634L8] },
{ "ltc2634-h12", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2634H12] },
{ "ltc2634-h10", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2634H10] },
{ "ltc2634-h8", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2634H8] },
{ "ltc2636-l12", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2636L12] },
{ "ltc2636-l10", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2636L10] },
{ "ltc2636-l8", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2636L8] },
{ "ltc2636-h12", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2636H12] },
{ "ltc2636-h10", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2636H10] },
{ "ltc2636-h8", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2636H8] },
{}
};
MODULE_DEVICE_TABLE(spi, ltc2632_id);
static const struct of_device_id ltc2632_of_match[] = {
{
.compatible = "lltc,ltc2632-l12",
.data = &ltc2632_chip_info_tbl[ID_LTC2632L12]
}, {
.compatible = "lltc,ltc2632-l10",
.data = &ltc2632_chip_info_tbl[ID_LTC2632L10]
}, {
.compatible = "lltc,ltc2632-l8",
.data = &ltc2632_chip_info_tbl[ID_LTC2632L8]
}, {
.compatible = "lltc,ltc2632-h12",
.data = &ltc2632_chip_info_tbl[ID_LTC2632H12]
}, {
.compatible = "lltc,ltc2632-h10",
.data = &ltc2632_chip_info_tbl[ID_LTC2632H10]
}, {
.compatible = "lltc,ltc2632-h8",
.data = &ltc2632_chip_info_tbl[ID_LTC2632H8]
}, {
.compatible = "lltc,ltc2634-l12",
.data = &ltc2632_chip_info_tbl[ID_LTC2634L12]
}, {
.compatible = "lltc,ltc2634-l10",
.data = &ltc2632_chip_info_tbl[ID_LTC2634L10]
}, {
.compatible = "lltc,ltc2634-l8",
.data = &ltc2632_chip_info_tbl[ID_LTC2634L8]
}, {
.compatible = "lltc,ltc2634-h12",
.data = &ltc2632_chip_info_tbl[ID_LTC2634H12]
}, {
.compatible = "lltc,ltc2634-h10",
.data = &ltc2632_chip_info_tbl[ID_LTC2634H10]
}, {
.compatible = "lltc,ltc2634-h8",
.data = &ltc2632_chip_info_tbl[ID_LTC2634H8]
}, {
.compatible = "lltc,ltc2636-l12",
.data = &ltc2632_chip_info_tbl[ID_LTC2636L12]
}, {
.compatible = "lltc,ltc2636-l10",
.data = &ltc2632_chip_info_tbl[ID_LTC2636L10]
}, {
.compatible = "lltc,ltc2636-l8",
.data = &ltc2632_chip_info_tbl[ID_LTC2636L8]
}, {
.compatible = "lltc,ltc2636-h12",
.data = &ltc2632_chip_info_tbl[ID_LTC2636H12]
}, {
.compatible = "lltc,ltc2636-h10",
.data = &ltc2632_chip_info_tbl[ID_LTC2636H10]
}, {
.compatible = "lltc,ltc2636-h8",
.data = &ltc2632_chip_info_tbl[ID_LTC2636H8]
},
{}
};
MODULE_DEVICE_TABLE(of, ltc2632_of_match);
static struct spi_driver ltc2632_driver = {
.driver = {
.name = "ltc2632",
.of_match_table = of_match_ptr(ltc2632_of_match),
},
.probe = ltc2632_probe,
.remove = ltc2632_remove,
.id_table = ltc2632_id,
};
module_spi_driver(ltc2632_driver);
MODULE_AUTHOR("Maxime Roussin-Belanger <maxime.roussinbelanger@gmail.com>");
MODULE_DESCRIPTION("LTC2632 DAC SPI driver");
MODULE_LICENSE("GPL v2");
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