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linux/drivers/iio/dac/ad5686.c
Mircea Caprioru 0e76df5c97 iio: dac: ad5686: fix bit shift read register 
This patch solves the register readback issue with the bit shift. When the
dac resolution was lower than the register size (ex. 12 bits out of 16
bits) the readback value was not shifted with the difference in bits and
the value was higher. Also a mask is applied on the read value in order to
get the value relative to the actual bit size.

Fixes: 0357e488b8 ("iio:dac:ad5686: Refactor the driver")
Signed-off-by: Mircea Caprioru <mircea.caprioru@analog.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2018-12-08 15:45:09 +00:00

493 lines
11 KiB
C
Raw Blame History

// SPDX-License-Identifier: GPL-2.0+
/*
* AD5686R, AD5685R, AD5684R Digital to analog converters driver
*
* Copyright 2011 Analog Devices Inc.
*/
#include <linux/interrupt.h>
#include <linux/fs.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/regulator/consumer.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include "ad5686.h"
static const char * const ad5686_powerdown_modes[] = {
"1kohm_to_gnd",
"100kohm_to_gnd",
"three_state"
};
static int ad5686_get_powerdown_mode(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan)
{
struct ad5686_state *st = iio_priv(indio_dev);
return ((st->pwr_down_mode >> (chan->channel * 2)) & 0x3) - 1;
}
static int ad5686_set_powerdown_mode(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan,
unsigned int mode)
{
struct ad5686_state *st = iio_priv(indio_dev);
st->pwr_down_mode &= ~(0x3 << (chan->channel * 2));
st->pwr_down_mode |= ((mode + 1) << (chan->channel * 2));
return 0;
}
static const struct iio_enum ad5686_powerdown_mode_enum = {
.items = ad5686_powerdown_modes,
.num_items = ARRAY_SIZE(ad5686_powerdown_modes),
.get = ad5686_get_powerdown_mode,
.set = ad5686_set_powerdown_mode,
};
static ssize_t ad5686_read_dac_powerdown(struct iio_dev *indio_dev,
uintptr_t private, const struct iio_chan_spec *chan, char *buf)
{
struct ad5686_state *st = iio_priv(indio_dev);
return sprintf(buf, "%d\n", !!(st->pwr_down_mask &
(0x3 << (chan->channel * 2))));
}
static ssize_t ad5686_write_dac_powerdown(struct iio_dev *indio_dev,
uintptr_t private,
const struct iio_chan_spec *chan,
const char *buf,
size_t len)
{
bool readin;
int ret;
struct ad5686_state *st = iio_priv(indio_dev);
unsigned int val, ref_bit_msk;
u8 shift;
ret = strtobool(buf, &readin);
if (ret)
return ret;
if (readin)
st->pwr_down_mask |= (0x3 << (chan->channel * 2));
else
st->pwr_down_mask &= ~(0x3 << (chan->channel * 2));
switch (st->chip_info->regmap_type) {
case AD5310_REGMAP:
shift = 9;
ref_bit_msk = AD5310_REF_BIT_MSK;
break;
case AD5683_REGMAP:
shift = 13;
ref_bit_msk = AD5683_REF_BIT_MSK;
break;
case AD5686_REGMAP:
shift = 0;
ref_bit_msk = 0;
break;
case AD5693_REGMAP:
shift = 13;
ref_bit_msk = AD5693_REF_BIT_MSK;
break;
default:
return -EINVAL;
}
val = ((st->pwr_down_mask & st->pwr_down_mode) << shift);
if (!st->use_internal_vref)
val |= ref_bit_msk;
ret = st->write(st, AD5686_CMD_POWERDOWN_DAC, 0, val);
return ret ? ret : len;
}
static int ad5686_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val,
int *val2,
long m)
{
struct ad5686_state *st = iio_priv(indio_dev);
int ret;
switch (m) {
case IIO_CHAN_INFO_RAW:
mutex_lock(&indio_dev->mlock);
ret = st->read(st, chan->address);
mutex_unlock(&indio_dev->mlock);
if (ret < 0)
return ret;
*val = (ret >> chan->scan_type.shift) &
GENMASK(chan->scan_type.realbits - 1, 0);
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
*val = st->vref_mv;
*val2 = chan->scan_type.realbits;
return IIO_VAL_FRACTIONAL_LOG2;
}
return -EINVAL;
}
static int ad5686_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val,
int val2,
long mask)
{
struct ad5686_state *st = iio_priv(indio_dev);
int ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
if (val > (1 << chan->scan_type.realbits) || val < 0)
return -EINVAL;
mutex_lock(&indio_dev->mlock);
ret = st->write(st,
AD5686_CMD_WRITE_INPUT_N_UPDATE_N,
chan->address,
val << chan->scan_type.shift);
mutex_unlock(&indio_dev->mlock);
break;
default:
ret = -EINVAL;
}
return ret;
}
static const struct iio_info ad5686_info = {
.read_raw = ad5686_read_raw,
.write_raw = ad5686_write_raw,
};
static const struct iio_chan_spec_ext_info ad5686_ext_info[] = {
{
.name = "powerdown",
.read = ad5686_read_dac_powerdown,
.write = ad5686_write_dac_powerdown,
.shared = IIO_SEPARATE,
},
IIO_ENUM("powerdown_mode", IIO_SEPARATE, &ad5686_powerdown_mode_enum),
IIO_ENUM_AVAILABLE("powerdown_mode", &ad5686_powerdown_mode_enum),
{ },
};
#define AD5868_CHANNEL(chan, addr, bits, _shift) { \
.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 = addr, \
.scan_type = { \
.sign = 'u', \
.realbits = (bits), \
.storagebits = 16, \
.shift = (_shift), \
}, \
.ext_info = ad5686_ext_info, \
}
#define DECLARE_AD5693_CHANNELS(name, bits, _shift) \
static struct iio_chan_spec name[] = { \
AD5868_CHANNEL(0, 0, bits, _shift), \
}
#define DECLARE_AD5686_CHANNELS(name, bits, _shift) \
static struct iio_chan_spec name[] = { \
AD5868_CHANNEL(0, 1, bits, _shift), \
AD5868_CHANNEL(1, 2, bits, _shift), \
AD5868_CHANNEL(2, 4, bits, _shift), \
AD5868_CHANNEL(3, 8, bits, _shift), \
}
#define DECLARE_AD5676_CHANNELS(name, bits, _shift) \
static struct iio_chan_spec name[] = { \
AD5868_CHANNEL(0, 0, bits, _shift), \
AD5868_CHANNEL(1, 1, bits, _shift), \
AD5868_CHANNEL(2, 2, bits, _shift), \
AD5868_CHANNEL(3, 3, bits, _shift), \
AD5868_CHANNEL(4, 4, bits, _shift), \
AD5868_CHANNEL(5, 5, bits, _shift), \
AD5868_CHANNEL(6, 6, bits, _shift), \
AD5868_CHANNEL(7, 7, bits, _shift), \
}
DECLARE_AD5693_CHANNELS(ad5310r_channels, 10, 2);
DECLARE_AD5693_CHANNELS(ad5311r_channels, 10, 6);
DECLARE_AD5676_CHANNELS(ad5672_channels, 12, 4);
DECLARE_AD5676_CHANNELS(ad5676_channels, 16, 0);
DECLARE_AD5686_CHANNELS(ad5684_channels, 12, 4);
DECLARE_AD5686_CHANNELS(ad5685r_channels, 14, 2);
DECLARE_AD5686_CHANNELS(ad5686_channels, 16, 0);
DECLARE_AD5693_CHANNELS(ad5693_channels, 16, 0);
DECLARE_AD5693_CHANNELS(ad5692r_channels, 14, 2);
DECLARE_AD5693_CHANNELS(ad5691r_channels, 12, 4);
static const struct ad5686_chip_info ad5686_chip_info_tbl[] = {
[ID_AD5310R] = {
.channels = ad5310r_channels,
.int_vref_mv = 2500,
.num_channels = 1,
.regmap_type = AD5310_REGMAP,
},
[ID_AD5311R] = {
.channels = ad5311r_channels,
.int_vref_mv = 2500,
.num_channels = 1,
.regmap_type = AD5693_REGMAP,
},
[ID_AD5671R] = {
.channels = ad5672_channels,
.int_vref_mv = 2500,
.num_channels = 8,
.regmap_type = AD5686_REGMAP,
},
[ID_AD5672R] = {
.channels = ad5672_channels,
.int_vref_mv = 2500,
.num_channels = 8,
.regmap_type = AD5686_REGMAP,
},
[ID_AD5675R] = {
.channels = ad5676_channels,
.int_vref_mv = 2500,
.num_channels = 8,
.regmap_type = AD5686_REGMAP,
},
[ID_AD5676] = {
.channels = ad5676_channels,
.num_channels = 8,
.regmap_type = AD5686_REGMAP,
},
[ID_AD5676R] = {
.channels = ad5676_channels,
.int_vref_mv = 2500,
.num_channels = 8,
.regmap_type = AD5686_REGMAP,
},
[ID_AD5681R] = {
.channels = ad5691r_channels,
.int_vref_mv = 2500,
.num_channels = 1,
.regmap_type = AD5683_REGMAP,
},
[ID_AD5682R] = {
.channels = ad5692r_channels,
.int_vref_mv = 2500,
.num_channels = 1,
.regmap_type = AD5683_REGMAP,
},
[ID_AD5683] = {
.channels = ad5693_channels,
.num_channels = 1,
.regmap_type = AD5683_REGMAP,
},
[ID_AD5683R] = {
.channels = ad5693_channels,
.int_vref_mv = 2500,
.num_channels = 1,
.regmap_type = AD5683_REGMAP,
},
[ID_AD5684] = {
.channels = ad5684_channels,
.num_channels = 4,
.regmap_type = AD5686_REGMAP,
},
[ID_AD5684R] = {
.channels = ad5684_channels,
.int_vref_mv = 2500,
.num_channels = 4,
.regmap_type = AD5686_REGMAP,
},
[ID_AD5685R] = {
.channels = ad5685r_channels,
.int_vref_mv = 2500,
.num_channels = 4,
.regmap_type = AD5686_REGMAP,
},
[ID_AD5686] = {
.channels = ad5686_channels,
.num_channels = 4,
.regmap_type = AD5686_REGMAP,
},
[ID_AD5686R] = {
.channels = ad5686_channels,
.int_vref_mv = 2500,
.num_channels = 4,
.regmap_type = AD5686_REGMAP,
},
[ID_AD5691R] = {
.channels = ad5691r_channels,
.int_vref_mv = 2500,
.num_channels = 1,
.regmap_type = AD5693_REGMAP,
},
[ID_AD5692R] = {
.channels = ad5692r_channels,
.int_vref_mv = 2500,
.num_channels = 1,
.regmap_type = AD5693_REGMAP,
},
[ID_AD5693] = {
.channels = ad5693_channels,
.num_channels = 1,
.regmap_type = AD5693_REGMAP,
},
[ID_AD5693R] = {
.channels = ad5693_channels,
.int_vref_mv = 2500,
.num_channels = 1,
.regmap_type = AD5693_REGMAP,
},
[ID_AD5694] = {
.channels = ad5684_channels,
.num_channels = 4,
.regmap_type = AD5686_REGMAP,
},
[ID_AD5694R] = {
.channels = ad5684_channels,
.int_vref_mv = 2500,
.num_channels = 4,
.regmap_type = AD5686_REGMAP,
},
[ID_AD5696] = {
.channels = ad5686_channels,
.num_channels = 4,
.regmap_type = AD5686_REGMAP,
},
[ID_AD5696R] = {
.channels = ad5686_channels,
.int_vref_mv = 2500,
.num_channels = 4,
.regmap_type = AD5686_REGMAP,
},
};
int ad5686_probe(struct device *dev,
enum ad5686_supported_device_ids chip_type,
const char *name, ad5686_write_func write,
ad5686_read_func read)
{
struct ad5686_state *st;
struct iio_dev *indio_dev;
unsigned int val, ref_bit_msk;
u8 cmd;
int ret, i, voltage_uv = 0;
indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
if (indio_dev == NULL)
return -ENOMEM;
st = iio_priv(indio_dev);
dev_set_drvdata(dev, indio_dev);
st->dev = dev;
st->write = write;
st->read = read;
st->reg = devm_regulator_get_optional(dev, "vcc");
if (!IS_ERR(st->reg)) {
ret = regulator_enable(st->reg);
if (ret)
return ret;
ret = regulator_get_voltage(st->reg);
if (ret < 0)
goto error_disable_reg;
voltage_uv = ret;
}
st->chip_info = &ad5686_chip_info_tbl[chip_type];
if (voltage_uv)
st->vref_mv = voltage_uv / 1000;
else
st->vref_mv = st->chip_info->int_vref_mv;
/* Set all the power down mode for all channels to 1K pulldown */
for (i = 0; i < st->chip_info->num_channels; i++)
st->pwr_down_mode |= (0x01 << (i * 2));
indio_dev->dev.parent = dev;
indio_dev->name = name;
indio_dev->info = &ad5686_info;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = st->chip_info->channels;
indio_dev->num_channels = st->chip_info->num_channels;
switch (st->chip_info->regmap_type) {
case AD5310_REGMAP:
cmd = AD5686_CMD_CONTROL_REG;
ref_bit_msk = AD5310_REF_BIT_MSK;
st->use_internal_vref = !voltage_uv;
break;
case AD5683_REGMAP:
cmd = AD5686_CMD_CONTROL_REG;
ref_bit_msk = AD5683_REF_BIT_MSK;
st->use_internal_vref = !voltage_uv;
break;
case AD5686_REGMAP:
cmd = AD5686_CMD_INTERNAL_REFER_SETUP;
ref_bit_msk = 0;
break;
case AD5693_REGMAP:
cmd = AD5686_CMD_CONTROL_REG;
ref_bit_msk = AD5693_REF_BIT_MSK;
st->use_internal_vref = !voltage_uv;
break;
default:
ret = -EINVAL;
goto error_disable_reg;
}
val = (voltage_uv | ref_bit_msk);
ret = st->write(st, cmd, 0, !!val);
if (ret)
goto error_disable_reg;
ret = iio_device_register(indio_dev);
if (ret)
goto error_disable_reg;
return 0;
error_disable_reg:
if (!IS_ERR(st->reg))
regulator_disable(st->reg);
return ret;
}
EXPORT_SYMBOL_GPL(ad5686_probe);
int ad5686_remove(struct device *dev)
{
struct iio_dev *indio_dev = dev_get_drvdata(dev);
struct ad5686_state *st = iio_priv(indio_dev);
iio_device_unregister(indio_dev);
if (!IS_ERR(st->reg))
regulator_disable(st->reg);
return 0;
}
EXPORT_SYMBOL_GPL(ad5686_remove);
MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
MODULE_DESCRIPTION("Analog Devices AD5686/85/84 DAC");
MODULE_LICENSE("GPL v2");
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