linux/drivers/iio/dac/ad5770r.c
Jonathan Cameron eff19f6b9e iio: dac: ad5770r: Use device_for_each_child_node_scoped()
Switching to the _scoped() version removes the need for manual
calling of fwnode_handle_put() in the paths where the code
exits the loop early. In this case that's all in error paths.

Cc: Nuno Sá <nuno.sa@analog.com>
Reviewed-by: Nuno Sa <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20240330185305.1319844-9-jic23@kernel.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2024-04-06 11:18:51 +01:00

694 lines
17 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* AD5770R Digital to analog converters driver
*
* Copyright 2018 Analog Devices Inc.
*/
#include <linux/bits.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/gpio/consumer.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/property.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>
#include <linux/spi/spi.h>
#define ADI_SPI_IF_CONFIG_A 0x00
#define ADI_SPI_IF_CONFIG_B 0x01
#define ADI_SPI_IF_DEVICE_CONFIG 0x02
#define ADI_SPI_IF_CHIP_TYPE 0x03
#define ADI_SPI_IF_PRODUCT_ID_L 0x04
#define ADI_SPI_IF_PRODUCT_ID_H 0x05
#define ADI_SPI_IF_CHIP_GRADE 0x06
#define ADI_SPI_IF_SCRACTH_PAD 0x0A
#define ADI_SPI_IF_SPI_REVISION 0x0B
#define ADI_SPI_IF_SPI_VENDOR_L 0x0C
#define ADI_SPI_IF_SPI_VENDOR_H 0x0D
#define ADI_SPI_IF_SPI_STREAM_MODE 0x0E
#define ADI_SPI_IF_CONFIG_C 0x10
#define ADI_SPI_IF_STATUS_A 0x11
/* ADI_SPI_IF_CONFIG_A */
#define ADI_SPI_IF_SW_RESET_MSK (BIT(0) | BIT(7))
#define ADI_SPI_IF_SW_RESET_SEL(x) ((x) & ADI_SPI_IF_SW_RESET_MSK)
#define ADI_SPI_IF_ADDR_ASC_MSK (BIT(2) | BIT(5))
#define ADI_SPI_IF_ADDR_ASC_SEL(x) (((x) << 2) & ADI_SPI_IF_ADDR_ASC_MSK)
/* ADI_SPI_IF_CONFIG_B */
#define ADI_SPI_IF_SINGLE_INS_MSK BIT(7)
#define ADI_SPI_IF_SINGLE_INS_SEL(x) FIELD_PREP(ADI_SPI_IF_SINGLE_INS_MSK, x)
#define ADI_SPI_IF_SHORT_INS_MSK BIT(7)
#define ADI_SPI_IF_SHORT_INS_SEL(x) FIELD_PREP(ADI_SPI_IF_SINGLE_INS_MSK, x)
/* ADI_SPI_IF_CONFIG_C */
#define ADI_SPI_IF_STRICT_REG_MSK BIT(5)
#define ADI_SPI_IF_STRICT_REG_GET(x) FIELD_GET(ADI_SPI_IF_STRICT_REG_MSK, x)
/* AD5770R configuration registers */
#define AD5770R_CHANNEL_CONFIG 0x14
#define AD5770R_OUTPUT_RANGE(ch) (0x15 + (ch))
#define AD5770R_FILTER_RESISTOR(ch) (0x1D + (ch))
#define AD5770R_REFERENCE 0x1B
#define AD5770R_DAC_LSB(ch) (0x26 + 2 * (ch))
#define AD5770R_DAC_MSB(ch) (0x27 + 2 * (ch))
#define AD5770R_CH_SELECT 0x34
#define AD5770R_CH_ENABLE 0x44
/* AD5770R_CHANNEL_CONFIG */
#define AD5770R_CFG_CH0_SINK_EN(x) (((x) & 0x1) << 7)
#define AD5770R_CFG_SHUTDOWN_B(x, ch) (((x) & 0x1) << (ch))
/* AD5770R_OUTPUT_RANGE */
#define AD5770R_RANGE_OUTPUT_SCALING(x) (((x) & GENMASK(5, 0)) << 2)
#define AD5770R_RANGE_MODE(x) ((x) & GENMASK(1, 0))
/* AD5770R_REFERENCE */
#define AD5770R_REF_RESISTOR_SEL(x) (((x) & 0x1) << 2)
#define AD5770R_REF_SEL(x) ((x) & GENMASK(1, 0))
/* AD5770R_CH_ENABLE */
#define AD5770R_CH_SET(x, ch) (((x) & 0x1) << (ch))
#define AD5770R_MAX_CHANNELS 6
#define AD5770R_MAX_CH_MODES 14
#define AD5770R_LOW_VREF_mV 1250
#define AD5770R_HIGH_VREF_mV 2500
enum ad5770r_ch0_modes {
AD5770R_CH0_0_300 = 0,
AD5770R_CH0_NEG_60_0,
AD5770R_CH0_NEG_60_300
};
enum ad5770r_ch1_modes {
AD5770R_CH1_0_140_LOW_HEAD = 1,
AD5770R_CH1_0_140_LOW_NOISE,
AD5770R_CH1_0_250
};
enum ad5770r_ch2_5_modes {
AD5770R_CH_LOW_RANGE = 0,
AD5770R_CH_HIGH_RANGE
};
enum ad5770r_ref_v {
AD5770R_EXT_2_5_V = 0,
AD5770R_INT_1_25_V_OUT_ON,
AD5770R_EXT_1_25_V,
AD5770R_INT_1_25_V_OUT_OFF
};
enum ad5770r_output_filter_resistor {
AD5770R_FILTER_60_OHM = 0x0,
AD5770R_FILTER_5_6_KOHM = 0x5,
AD5770R_FILTER_11_2_KOHM,
AD5770R_FILTER_22_2_KOHM,
AD5770R_FILTER_44_4_KOHM,
AD5770R_FILTER_104_KOHM,
};
struct ad5770r_out_range {
u8 out_scale;
u8 out_range_mode;
};
/**
* struct ad5770r_state - driver instance specific data
* @spi: spi_device
* @regmap: regmap
* @vref_reg: fixed regulator for reference configuration
* @gpio_reset: gpio descriptor
* @output_mode: array contains channels output ranges
* @vref: reference value
* @ch_pwr_down: powerdown flags
* @internal_ref: internal reference flag
* @external_res: external 2.5k resistor flag
* @transf_buf: cache aligned buffer for spi read/write
*/
struct ad5770r_state {
struct spi_device *spi;
struct regmap *regmap;
struct regulator *vref_reg;
struct gpio_desc *gpio_reset;
struct ad5770r_out_range output_mode[AD5770R_MAX_CHANNELS];
int vref;
bool ch_pwr_down[AD5770R_MAX_CHANNELS];
bool internal_ref;
bool external_res;
u8 transf_buf[2] __aligned(IIO_DMA_MINALIGN);
};
static const struct regmap_config ad5770r_spi_regmap_config = {
.reg_bits = 8,
.val_bits = 8,
.read_flag_mask = BIT(7),
};
struct ad5770r_output_modes {
unsigned int ch;
u8 mode;
int min;
int max;
};
static struct ad5770r_output_modes ad5770r_rng_tbl[] = {
{ 0, AD5770R_CH0_0_300, 0, 300 },
{ 0, AD5770R_CH0_NEG_60_0, -60, 0 },
{ 0, AD5770R_CH0_NEG_60_300, -60, 300 },
{ 1, AD5770R_CH1_0_140_LOW_HEAD, 0, 140 },
{ 1, AD5770R_CH1_0_140_LOW_NOISE, 0, 140 },
{ 1, AD5770R_CH1_0_250, 0, 250 },
{ 2, AD5770R_CH_LOW_RANGE, 0, 55 },
{ 2, AD5770R_CH_HIGH_RANGE, 0, 150 },
{ 3, AD5770R_CH_LOW_RANGE, 0, 45 },
{ 3, AD5770R_CH_HIGH_RANGE, 0, 100 },
{ 4, AD5770R_CH_LOW_RANGE, 0, 45 },
{ 4, AD5770R_CH_HIGH_RANGE, 0, 100 },
{ 5, AD5770R_CH_LOW_RANGE, 0, 45 },
{ 5, AD5770R_CH_HIGH_RANGE, 0, 100 },
};
static const unsigned int ad5770r_filter_freqs[] = {
153, 357, 715, 1400, 2800, 262000,
};
static const unsigned int ad5770r_filter_reg_vals[] = {
AD5770R_FILTER_104_KOHM,
AD5770R_FILTER_44_4_KOHM,
AD5770R_FILTER_22_2_KOHM,
AD5770R_FILTER_11_2_KOHM,
AD5770R_FILTER_5_6_KOHM,
AD5770R_FILTER_60_OHM
};
static int ad5770r_set_output_mode(struct ad5770r_state *st,
const struct ad5770r_out_range *out_mode,
int channel)
{
unsigned int regval;
regval = AD5770R_RANGE_OUTPUT_SCALING(out_mode->out_scale) |
AD5770R_RANGE_MODE(out_mode->out_range_mode);
return regmap_write(st->regmap,
AD5770R_OUTPUT_RANGE(channel), regval);
}
static int ad5770r_set_reference(struct ad5770r_state *st)
{
unsigned int regval;
regval = AD5770R_REF_RESISTOR_SEL(st->external_res);
if (st->internal_ref) {
regval |= AD5770R_REF_SEL(AD5770R_INT_1_25_V_OUT_OFF);
} else {
switch (st->vref) {
case AD5770R_LOW_VREF_mV:
regval |= AD5770R_REF_SEL(AD5770R_EXT_1_25_V);
break;
case AD5770R_HIGH_VREF_mV:
regval |= AD5770R_REF_SEL(AD5770R_EXT_2_5_V);
break;
default:
regval = AD5770R_REF_SEL(AD5770R_INT_1_25_V_OUT_OFF);
break;
}
}
return regmap_write(st->regmap, AD5770R_REFERENCE, regval);
}
static int ad5770r_soft_reset(struct ad5770r_state *st)
{
return regmap_write(st->regmap, ADI_SPI_IF_CONFIG_A,
ADI_SPI_IF_SW_RESET_SEL(1));
}
static int ad5770r_reset(struct ad5770r_state *st)
{
/* Perform software reset if no GPIO provided */
if (!st->gpio_reset)
return ad5770r_soft_reset(st);
gpiod_set_value_cansleep(st->gpio_reset, 0);
usleep_range(10, 20);
gpiod_set_value_cansleep(st->gpio_reset, 1);
/* data must not be written during reset timeframe */
usleep_range(100, 200);
return 0;
}
static int ad5770r_get_range(struct ad5770r_state *st,
int ch, int *min, int *max)
{
int i;
u8 tbl_ch, tbl_mode, out_range;
out_range = st->output_mode[ch].out_range_mode;
for (i = 0; i < AD5770R_MAX_CH_MODES; i++) {
tbl_ch = ad5770r_rng_tbl[i].ch;
tbl_mode = ad5770r_rng_tbl[i].mode;
if (tbl_ch == ch && tbl_mode == out_range) {
*min = ad5770r_rng_tbl[i].min;
*max = ad5770r_rng_tbl[i].max;
return 0;
}
}
return -EINVAL;
}
static int ad5770r_get_filter_freq(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan, int *freq)
{
struct ad5770r_state *st = iio_priv(indio_dev);
int ret;
unsigned int regval, i;
ret = regmap_read(st->regmap,
AD5770R_FILTER_RESISTOR(chan->channel), &regval);
if (ret < 0)
return ret;
for (i = 0; i < ARRAY_SIZE(ad5770r_filter_reg_vals); i++)
if (regval == ad5770r_filter_reg_vals[i])
break;
if (i == ARRAY_SIZE(ad5770r_filter_reg_vals))
return -EINVAL;
*freq = ad5770r_filter_freqs[i];
return IIO_VAL_INT;
}
static int ad5770r_set_filter_freq(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan,
unsigned int freq)
{
struct ad5770r_state *st = iio_priv(indio_dev);
unsigned int regval, i;
for (i = 0; i < ARRAY_SIZE(ad5770r_filter_freqs); i++)
if (ad5770r_filter_freqs[i] >= freq)
break;
if (i == ARRAY_SIZE(ad5770r_filter_freqs))
return -EINVAL;
regval = ad5770r_filter_reg_vals[i];
return regmap_write(st->regmap, AD5770R_FILTER_RESISTOR(chan->channel),
regval);
}
static int ad5770r_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long info)
{
struct ad5770r_state *st = iio_priv(indio_dev);
int max, min, ret;
u16 buf16;
switch (info) {
case IIO_CHAN_INFO_RAW:
ret = regmap_bulk_read(st->regmap,
chan->address,
st->transf_buf, 2);
if (ret)
return 0;
buf16 = st->transf_buf[0] + (st->transf_buf[1] << 8);
*val = buf16 >> 2;
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
ret = ad5770r_get_range(st, chan->channel, &min, &max);
if (ret < 0)
return ret;
*val = max - min;
/* There is no sign bit. (negative current is mapped from 0)
* (sourced/sinked) current = raw * scale + offset
* where offset in case of CH0 can be negative.
*/
*val2 = 14;
return IIO_VAL_FRACTIONAL_LOG2;
case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
return ad5770r_get_filter_freq(indio_dev, chan, val);
case IIO_CHAN_INFO_OFFSET:
ret = ad5770r_get_range(st, chan->channel, &min, &max);
if (ret < 0)
return ret;
*val = min;
return IIO_VAL_INT;
default:
return -EINVAL;
}
}
static int ad5770r_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val, int val2, long info)
{
struct ad5770r_state *st = iio_priv(indio_dev);
switch (info) {
case IIO_CHAN_INFO_RAW:
st->transf_buf[0] = ((u16)val >> 6);
st->transf_buf[1] = (val & GENMASK(5, 0)) << 2;
return regmap_bulk_write(st->regmap, chan->address,
st->transf_buf, 2);
case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
return ad5770r_set_filter_freq(indio_dev, chan, val);
default:
return -EINVAL;
}
}
static int ad5770r_read_freq_avail(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
const int **vals, int *type, int *length,
long mask)
{
switch (mask) {
case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
*type = IIO_VAL_INT;
*vals = ad5770r_filter_freqs;
*length = ARRAY_SIZE(ad5770r_filter_freqs);
return IIO_AVAIL_LIST;
}
return -EINVAL;
}
static int ad5770r_reg_access(struct iio_dev *indio_dev,
unsigned int reg,
unsigned int writeval,
unsigned int *readval)
{
struct ad5770r_state *st = iio_priv(indio_dev);
if (readval)
return regmap_read(st->regmap, reg, readval);
else
return regmap_write(st->regmap, reg, writeval);
}
static const struct iio_info ad5770r_info = {
.read_raw = ad5770r_read_raw,
.write_raw = ad5770r_write_raw,
.read_avail = ad5770r_read_freq_avail,
.debugfs_reg_access = &ad5770r_reg_access,
};
static int ad5770r_store_output_range(struct ad5770r_state *st,
int min, int max, int index)
{
int i;
for (i = 0; i < AD5770R_MAX_CH_MODES; i++) {
if (ad5770r_rng_tbl[i].ch != index)
continue;
if (ad5770r_rng_tbl[i].min != min ||
ad5770r_rng_tbl[i].max != max)
continue;
st->output_mode[index].out_range_mode = ad5770r_rng_tbl[i].mode;
return 0;
}
return -EINVAL;
}
static ssize_t ad5770r_read_dac_powerdown(struct iio_dev *indio_dev,
uintptr_t private,
const struct iio_chan_spec *chan,
char *buf)
{
struct ad5770r_state *st = iio_priv(indio_dev);
return sysfs_emit(buf, "%d\n", st->ch_pwr_down[chan->channel]);
}
static ssize_t ad5770r_write_dac_powerdown(struct iio_dev *indio_dev,
uintptr_t private,
const struct iio_chan_spec *chan,
const char *buf, size_t len)
{
struct ad5770r_state *st = iio_priv(indio_dev);
unsigned int regval;
unsigned int mask;
bool readin;
int ret;
ret = kstrtobool(buf, &readin);
if (ret)
return ret;
readin = !readin;
regval = AD5770R_CFG_SHUTDOWN_B(readin, chan->channel);
if (chan->channel == 0 &&
st->output_mode[0].out_range_mode > AD5770R_CH0_0_300) {
regval |= AD5770R_CFG_CH0_SINK_EN(readin);
mask = BIT(chan->channel) + BIT(7);
} else {
mask = BIT(chan->channel);
}
ret = regmap_update_bits(st->regmap, AD5770R_CHANNEL_CONFIG, mask,
regval);
if (ret)
return ret;
regval = AD5770R_CH_SET(readin, chan->channel);
ret = regmap_update_bits(st->regmap, AD5770R_CH_ENABLE,
BIT(chan->channel), regval);
if (ret)
return ret;
st->ch_pwr_down[chan->channel] = !readin;
return len;
}
static const struct iio_chan_spec_ext_info ad5770r_ext_info[] = {
{
.name = "powerdown",
.read = ad5770r_read_dac_powerdown,
.write = ad5770r_write_dac_powerdown,
.shared = IIO_SEPARATE,
},
{ }
};
#define AD5770R_IDAC_CHANNEL(index, reg) { \
.type = IIO_CURRENT, \
.address = reg, \
.indexed = 1, \
.channel = index, \
.output = 1, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
BIT(IIO_CHAN_INFO_SCALE) | \
BIT(IIO_CHAN_INFO_OFFSET) | \
BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY), \
.info_mask_shared_by_type_available = \
BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY), \
.ext_info = ad5770r_ext_info, \
}
static const struct iio_chan_spec ad5770r_channels[] = {
AD5770R_IDAC_CHANNEL(0, AD5770R_DAC_MSB(0)),
AD5770R_IDAC_CHANNEL(1, AD5770R_DAC_MSB(1)),
AD5770R_IDAC_CHANNEL(2, AD5770R_DAC_MSB(2)),
AD5770R_IDAC_CHANNEL(3, AD5770R_DAC_MSB(3)),
AD5770R_IDAC_CHANNEL(4, AD5770R_DAC_MSB(4)),
AD5770R_IDAC_CHANNEL(5, AD5770R_DAC_MSB(5)),
};
static int ad5770r_channel_config(struct ad5770r_state *st)
{
int ret, tmp[2], min, max;
unsigned int num;
num = device_get_child_node_count(&st->spi->dev);
if (num != AD5770R_MAX_CHANNELS)
return -EINVAL;
device_for_each_child_node_scoped(&st->spi->dev, child) {
ret = fwnode_property_read_u32(child, "reg", &num);
if (ret)
return ret;
if (num >= AD5770R_MAX_CHANNELS)
return -EINVAL;
ret = fwnode_property_read_u32_array(child,
"adi,range-microamp",
tmp, 2);
if (ret)
return ret;
min = tmp[0] / 1000;
max = tmp[1] / 1000;
ret = ad5770r_store_output_range(st, min, max, num);
if (ret)
return ret;
}
return 0;
}
static int ad5770r_init(struct ad5770r_state *st)
{
int ret, i;
st->gpio_reset = devm_gpiod_get_optional(&st->spi->dev, "reset",
GPIOD_OUT_HIGH);
if (IS_ERR(st->gpio_reset))
return PTR_ERR(st->gpio_reset);
/* Perform a reset */
ret = ad5770r_reset(st);
if (ret)
return ret;
/* Set output range */
ret = ad5770r_channel_config(st);
if (ret)
return ret;
for (i = 0; i < AD5770R_MAX_CHANNELS; i++) {
ret = ad5770r_set_output_mode(st, &st->output_mode[i], i);
if (ret)
return ret;
}
st->external_res = fwnode_property_read_bool(st->spi->dev.fwnode,
"adi,external-resistor");
ret = ad5770r_set_reference(st);
if (ret)
return ret;
/* Set outputs off */
ret = regmap_write(st->regmap, AD5770R_CHANNEL_CONFIG, 0x00);
if (ret)
return ret;
ret = regmap_write(st->regmap, AD5770R_CH_ENABLE, 0x00);
if (ret)
return ret;
for (i = 0; i < AD5770R_MAX_CHANNELS; i++)
st->ch_pwr_down[i] = true;
return ret;
}
static void ad5770r_disable_regulator(void *data)
{
struct ad5770r_state *st = data;
regulator_disable(st->vref_reg);
}
static int ad5770r_probe(struct spi_device *spi)
{
struct ad5770r_state *st;
struct iio_dev *indio_dev;
struct regmap *regmap;
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 = spi;
regmap = devm_regmap_init_spi(spi, &ad5770r_spi_regmap_config);
if (IS_ERR(regmap)) {
dev_err(&spi->dev, "Error initializing spi regmap: %ld\n",
PTR_ERR(regmap));
return PTR_ERR(regmap);
}
st->regmap = regmap;
st->vref_reg = devm_regulator_get_optional(&spi->dev, "vref");
if (!IS_ERR(st->vref_reg)) {
ret = regulator_enable(st->vref_reg);
if (ret) {
dev_err(&spi->dev,
"Failed to enable vref regulators: %d\n", ret);
return ret;
}
ret = devm_add_action_or_reset(&spi->dev,
ad5770r_disable_regulator,
st);
if (ret < 0)
return ret;
ret = regulator_get_voltage(st->vref_reg);
if (ret < 0)
return ret;
st->vref = ret / 1000;
} else {
if (PTR_ERR(st->vref_reg) == -ENODEV) {
st->vref = AD5770R_LOW_VREF_mV;
st->internal_ref = true;
} else {
return PTR_ERR(st->vref_reg);
}
}
indio_dev->name = spi_get_device_id(spi)->name;
indio_dev->info = &ad5770r_info;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = ad5770r_channels;
indio_dev->num_channels = ARRAY_SIZE(ad5770r_channels);
ret = ad5770r_init(st);
if (ret < 0) {
dev_err(&spi->dev, "AD5770R init failed\n");
return ret;
}
return devm_iio_device_register(&st->spi->dev, indio_dev);
}
static const struct of_device_id ad5770r_of_id[] = {
{ .compatible = "adi,ad5770r", },
{},
};
MODULE_DEVICE_TABLE(of, ad5770r_of_id);
static const struct spi_device_id ad5770r_id[] = {
{ "ad5770r", 0 },
{},
};
MODULE_DEVICE_TABLE(spi, ad5770r_id);
static struct spi_driver ad5770r_driver = {
.driver = {
.name = KBUILD_MODNAME,
.of_match_table = ad5770r_of_id,
},
.probe = ad5770r_probe,
.id_table = ad5770r_id,
};
module_spi_driver(ad5770r_driver);
MODULE_AUTHOR("Mircea Caprioru <mircea.caprioru@analog.com>");
MODULE_DESCRIPTION("Analog Devices AD5770R IDAC");
MODULE_LICENSE("GPL v2");