// SPDX-License-Identifier: GPL-2.0+
/*
* AD4000 SPI ADC driver
*
* Copyright 2024 Analog Devices Inc.
*/
#include <linux/bits.h>
#include <linux/bitfield.h>
#include <linux/byteorder/generic.h>
#include <linux/cleanup.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/math.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/gpio/consumer.h>
#include <linux/regulator/consumer.h>
#include <linux/spi/spi.h>
#include <linux/units.h>
#include <linux/util_macros.h>
#include <linux/iio/iio.h>
#include <linux/iio/buffer.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/iio/trigger_consumer.h>
#define AD4000_READ_COMMAND 0x54
#define AD4000_WRITE_COMMAND 0x14
#define AD4000_CONFIG_REG_DEFAULT 0xE1
/* AD4000 Configuration Register programmable bits */
#define AD4000_CFG_SPAN_COMP BIT(3) /* Input span compression */
#define AD4000_CFG_HIGHZ BIT(2) /* High impedance mode */
#define AD4000_SCALE_OPTIONS 2
#define __AD4000_DIFF_CHANNEL(_sign, _real_bits, _storage_bits, _reg_access) \
{ \
.type = IIO_VOLTAGE, \
.indexed = 1, \
.differential = 1, \
.channel = 0, \
.channel2 = 1, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
BIT(IIO_CHAN_INFO_SCALE), \
.info_mask_separate_available = _reg_access ? BIT(IIO_CHAN_INFO_SCALE) : 0,\
.scan_index = 0, \
.scan_type = { \
.sign = _sign, \
.realbits = _real_bits, \
.storagebits = _storage_bits, \
.shift = _storage_bits - _real_bits, \
.endianness = IIO_BE, \
}, \
}
#define AD4000_DIFF_CHANNEL(_sign, _real_bits, _reg_access) \
__AD4000_DIFF_CHANNEL((_sign), (_real_bits), \
((_real_bits) > 16 ? 32 : 16), (_reg_access))
#define AD4000_DIFF_CHANNELS(_sign, _real_bits, _reg_access) \
{ \
AD4000_DIFF_CHANNEL(_sign, _real_bits, _reg_access), \
IIO_CHAN_SOFT_TIMESTAMP(1), \
}
#define __AD4000_PSEUDO_DIFF_CHANNEL(_sign, _real_bits, _storage_bits, _reg_access)\
{ \
.type = IIO_VOLTAGE, \
.indexed = 1, \
.channel = 0, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
BIT(IIO_CHAN_INFO_SCALE) | \
BIT(IIO_CHAN_INFO_OFFSET), \
.info_mask_separate_available = _reg_access ? BIT(IIO_CHAN_INFO_SCALE) : 0,\
.scan_index = 0, \
.scan_type = { \
.sign = _sign, \
.realbits = _real_bits, \
.storagebits = _storage_bits, \
.shift = _storage_bits - _real_bits, \
.endianness = IIO_BE, \
}, \
}
#define AD4000_PSEUDO_DIFF_CHANNEL(_sign, _real_bits, _reg_access) \
__AD4000_PSEUDO_DIFF_CHANNEL((_sign), (_real_bits), \
((_real_bits) > 16 ? 32 : 16), (_reg_access))
#define AD4000_PSEUDO_DIFF_CHANNELS(_sign, _real_bits, _reg_access) \
{ \
AD4000_PSEUDO_DIFF_CHANNEL(_sign, _real_bits, _reg_access), \
IIO_CHAN_SOFT_TIMESTAMP(1), \
}
static const char * const ad4000_power_supplies[] = {
"vdd", "vio"
};
enum ad4000_sdi {
AD4000_SDI_MOSI,
AD4000_SDI_VIO,
AD4000_SDI_CS,
AD4000_SDI_GND,
};
/* maps adi,sdi-pin property value to enum */
static const char * const ad4000_sdi_pin[] = {
[AD4000_SDI_MOSI] = "sdi",
[AD4000_SDI_VIO] = "high",
[AD4000_SDI_CS] = "cs",
[AD4000_SDI_GND] = "low",
};
/* Gains stored as fractions of 1000 so they can be expressed by integers. */
static const int ad4000_gains[] = {
454, 909, 1000, 1900,
};
struct ad4000_time_spec {
int t_conv_ns;
int t_quiet2_ns;
};
/*
* Same timing specifications for all of AD4000, AD4001, ..., AD4008, AD4010,
* ADAQ4001, and ADAQ4003.
*/
static const struct ad4000_time_spec ad4000_t_spec = {
.t_conv_ns = 320,
.t_quiet2_ns = 60,
};
/* AD4020, AD4021, AD4022 */
static const struct ad4000_time_spec ad4020_t_spec = {
.t_conv_ns = 350,
.t_quiet2_ns = 60,
};
/* AD7983, AD7984 */
static const struct ad4000_time_spec ad7983_t_spec = {
.t_conv_ns = 500,
.t_quiet2_ns = 0,
};
/* AD7980, AD7982 */
static const struct ad4000_time_spec ad7980_t_spec = {
.t_conv_ns = 800,
.t_quiet2_ns = 0,
};
/* AD7946, AD7686, AD7688, AD7988-5, AD7693 */
static const struct ad4000_time_spec ad7686_t_spec = {
.t_conv_ns = 1600,
.t_quiet2_ns = 0,
};
/* AD7690 */
static const struct ad4000_time_spec ad7690_t_spec = {
.t_conv_ns = 2100,
.t_quiet2_ns = 0,
};
/* AD7942, AD7685, AD7687 */
static const struct ad4000_time_spec ad7687_t_spec = {
.t_conv_ns = 3200,
.t_quiet2_ns = 0,
};
/* AD7691 */
static const struct ad4000_time_spec ad7691_t_spec = {
.t_conv_ns = 3700,
.t_quiet2_ns = 0,
};
/* AD7988-1 */
static const struct ad4000_time_spec ad7988_1_t_spec = {
.t_conv_ns = 9500,
.t_quiet2_ns = 0,
};
struct ad4000_chip_info {
const char *dev_name;
struct iio_chan_spec chan_spec[2];
struct iio_chan_spec reg_access_chan_spec[2];
const struct ad4000_time_spec *time_spec;
bool has_hardware_gain;
};
static const struct ad4000_chip_info ad4000_chip_info = {
.dev_name = "ad4000",
.chan_spec = AD4000_PSEUDO_DIFF_CHANNELS('u', 16, 0),
.reg_access_chan_spec = AD4000_PSEUDO_DIFF_CHANNELS('u', 16, 1),
.time_spec = &ad4000_t_spec,
};
static const struct ad4000_chip_info ad4001_chip_info = {
.dev_name = "ad4001",
.chan_spec = AD4000_DIFF_CHANNELS('s', 16, 0),
.reg_access_chan_spec = AD4000_DIFF_CHANNELS('s', 16, 1),
.time_spec = &ad4000_t_spec,
};
static const struct ad4000_chip_info ad4002_chip_info = {
.dev_name = "ad4002",
.chan_spec = AD4000_PSEUDO_DIFF_CHANNELS('u', 18, 0),
.reg_access_chan_spec = AD4000_PSEUDO_DIFF_CHANNELS('u', 18, 1),
.time_spec = &ad4000_t_spec,
};
static const struct ad4000_chip_info ad4003_chip_info = {
.dev_name = "ad4003",
.chan_spec = AD4000_DIFF_CHANNELS('s', 18, 0),
.reg_access_chan_spec = AD4000_DIFF_CHANNELS('s', 18, 1),
.time_spec = &ad4000_t_spec,
};
static const struct ad4000_chip_info ad4004_chip_info = {
.dev_name = "ad4004",
.chan_spec = AD4000_PSEUDO_DIFF_CHANNELS('u', 16, 0),
.reg_access_chan_spec = AD4000_PSEUDO_DIFF_CHANNELS('u', 16, 1),
.time_spec = &ad4000_t_spec,
};
static const struct ad4000_chip_info ad4005_chip_info = {
.dev_name = "ad4005",
.chan_spec = AD4000_DIFF_CHANNELS('s', 16, 0),
.reg_access_chan_spec = AD4000_DIFF_CHANNELS('s', 16, 1),
.time_spec = &ad4000_t_spec,
};
static const struct ad4000_chip_info ad4006_chip_info = {
.dev_name = "ad4006",
.chan_spec = AD4000_PSEUDO_DIFF_CHANNELS('u', 18, 0),
.reg_access_chan_spec = AD4000_PSEUDO_DIFF_CHANNELS('u', 18, 1),
.time_spec = &ad4000_t_spec,
};
static const struct ad4000_chip_info ad4007_chip_info = {
.dev_name = "ad4007",
.chan_spec = AD4000_DIFF_CHANNELS('s', 18, 0),
.reg_access_chan_spec = AD4000_DIFF_CHANNELS('s', 18, 1),
.time_spec = &ad4000_t_spec,
};
static const struct ad4000_chip_info ad4008_chip_info = {
.dev_name = "ad4008",
.chan_spec = AD4000_PSEUDO_DIFF_CHANNELS('u', 16, 0),
.reg_access_chan_spec = AD4000_PSEUDO_DIFF_CHANNELS('u', 16, 1),
.time_spec = &ad4000_t_spec,
};
static const struct ad4000_chip_info ad4010_chip_info = {
.dev_name = "ad4010",
.chan_spec = AD4000_PSEUDO_DIFF_CHANNELS('u', 18, 0),
.reg_access_chan_spec = AD4000_PSEUDO_DIFF_CHANNELS('u', 18, 1),
.time_spec = &ad4000_t_spec,
};
static const struct ad4000_chip_info ad4011_chip_info = {
.dev_name = "ad4011",
.chan_spec = AD4000_DIFF_CHANNELS('s', 18, 0),
.reg_access_chan_spec = AD4000_DIFF_CHANNELS('s', 18, 1),
.time_spec = &ad4000_t_spec,
};
static const struct ad4000_chip_info ad4020_chip_info = {
.dev_name = "ad4020",
.chan_spec = AD4000_DIFF_CHANNELS('s', 20, 0),
.reg_access_chan_spec = AD4000_DIFF_CHANNELS('s', 20, 1),
.time_spec = &ad4020_t_spec,
};
static const struct ad4000_chip_info ad4021_chip_info = {
.dev_name = "ad4021",
.chan_spec = AD4000_DIFF_CHANNELS('s', 20, 0),
.reg_access_chan_spec = AD4000_DIFF_CHANNELS('s', 20, 1),
.time_spec = &ad4020_t_spec,
};
static const struct ad4000_chip_info ad4022_chip_info = {
.dev_name = "ad4022",
.chan_spec = AD4000_DIFF_CHANNELS('s', 20, 0),
.reg_access_chan_spec = AD4000_DIFF_CHANNELS('s', 20, 1),
.time_spec = &ad4020_t_spec,
};
static const struct ad4000_chip_info adaq4001_chip_info = {
.dev_name = "adaq4001",
.chan_spec = AD4000_DIFF_CHANNELS('s', 16, 0),
.reg_access_chan_spec = AD4000_DIFF_CHANNELS('s', 16, 1),
.time_spec = &ad4000_t_spec,
.has_hardware_gain = true,
};
static const struct ad4000_chip_info adaq4003_chip_info = {
.dev_name = "adaq4003",
.chan_spec = AD4000_DIFF_CHANNELS('s', 18, 0),
.reg_access_chan_spec = AD4000_DIFF_CHANNELS('s', 18, 1),
.time_spec = &ad4000_t_spec,
.has_hardware_gain = true,
};
static const struct ad4000_chip_info ad7685_chip_info = {
.dev_name = "ad7685",
.chan_spec = AD4000_PSEUDO_DIFF_CHANNELS('u', 16, 0),
.time_spec = &ad7687_t_spec,
};
static const struct ad4000_chip_info ad7686_chip_info = {
.dev_name = "ad7686",
.chan_spec = AD4000_PSEUDO_DIFF_CHANNELS('u', 16, 0),
.time_spec = &ad7686_t_spec,
};
static const struct ad4000_chip_info ad7687_chip_info = {
.dev_name = "ad7687",
.chan_spec = AD4000_DIFF_CHANNELS('s', 16, 0),
.time_spec = &ad7687_t_spec,
};
static const struct ad4000_chip_info ad7688_chip_info = {
.dev_name = "ad7688",
.chan_spec = AD4000_DIFF_CHANNELS('s', 16, 0),
.time_spec = &ad7686_t_spec,
};
static const struct ad4000_chip_info ad7690_chip_info = {
.dev_name = "ad7690",
.chan_spec = AD4000_DIFF_CHANNELS('s', 18, 0),
.time_spec = &ad7690_t_spec,
};
static const struct ad4000_chip_info ad7691_chip_info = {
.dev_name = "ad7691",
.chan_spec = AD4000_DIFF_CHANNELS('s', 18, 0),
.time_spec = &ad7691_t_spec,
};
static const struct ad4000_chip_info ad7693_chip_info = {
.dev_name = "ad7693",
.chan_spec = AD4000_DIFF_CHANNELS('s', 16, 0),
.time_spec = &ad7686_t_spec,
};
static const struct ad4000_chip_info ad7942_chip_info = {
.dev_name = "ad7942",
.chan_spec = AD4000_PSEUDO_DIFF_CHANNELS('u', 14, 0),
.time_spec = &ad7687_t_spec,
};
static const struct ad4000_chip_info ad7946_chip_info = {
.dev_name = "ad7946",
.chan_spec = AD4000_PSEUDO_DIFF_CHANNELS('u', 14, 0),
.time_spec = &ad7686_t_spec,
};
static const struct ad4000_chip_info ad7980_chip_info = {
.dev_name = "ad7980",
.chan_spec = AD4000_PSEUDO_DIFF_CHANNELS('u', 16, 0),
.time_spec = &ad7980_t_spec,
};
static const struct ad4000_chip_info ad7982_chip_info = {
.dev_name = "ad7982",
.chan_spec = AD4000_DIFF_CHANNELS('s', 18, 0),
.time_spec = &ad7980_t_spec,
};
static const struct ad4000_chip_info ad7983_chip_info = {
.dev_name = "ad7983",
.chan_spec = AD4000_PSEUDO_DIFF_CHANNELS('u', 16, 0),
.time_spec = &ad7983_t_spec,
};
static const struct ad4000_chip_info ad7984_chip_info = {
.dev_name = "ad7984",
.chan_spec = AD4000_DIFF_CHANNELS('s', 18, 0),
.time_spec = &ad7983_t_spec,
};
static const struct ad4000_chip_info ad7988_1_chip_info = {
.dev_name = "ad7988-1",
.chan_spec = AD4000_PSEUDO_DIFF_CHANNELS('u', 16, 0),
.time_spec = &ad7988_1_t_spec,
};
static const struct ad4000_chip_info ad7988_5_chip_info = {
.dev_name = "ad7988-5",
.chan_spec = AD4000_PSEUDO_DIFF_CHANNELS('u', 16, 0),
.time_spec = &ad7686_t_spec,
};
struct ad4000_state {
struct spi_device *spi;
struct gpio_desc *cnv_gpio;
struct spi_transfer xfers[2];
struct spi_message msg;
struct mutex lock; /* Protect read modify write cycle */
int vref_mv;
enum ad4000_sdi sdi_pin;
bool span_comp;
u16 gain_milli;
int scale_tbl[AD4000_SCALE_OPTIONS][2];
const struct ad4000_time_spec *time_spec;
/*
* DMA (thus cache coherency maintenance) requires the transfer buffers
* to live in their own cache lines.
*/
struct {
union {
__be16 sample_buf16;
__be32 sample_buf32;
} data;
aligned_s64 timestamp;
} scan __aligned(IIO_DMA_MINALIGN);
u8 tx_buf[2];
u8 rx_buf[2];
};
static void ad4000_fill_scale_tbl(struct ad4000_state *st,
struct iio_chan_spec const *chan)
{
int val, tmp0, tmp1;
int scale_bits;
u64 tmp2;
/*
* ADCs that output two's complement code have one less bit to express
* voltage magnitude.
*/
if (chan->scan_type.sign == 's')
scale_bits = chan->scan_type.realbits - 1;
else
scale_bits = chan->scan_type.realbits;
/*
* The gain is stored as a fraction of 1000 and, as we need to
* divide vref_mv by the gain, we invert the gain/1000 fraction.
* Also multiply by an extra MILLI to preserve precision.
* Thus, we have MILLI * MILLI equals MICRO as fraction numerator.
*/
val = mult_frac(st->vref_mv, MICRO, st->gain_milli);
/* Would multiply by NANO here but we multiplied by extra MILLI */
tmp2 = shift_right((u64)val * MICRO, scale_bits);
tmp0 = div_s64_rem(tmp2, NANO, &tmp1);
/* Store scale for when span compression is disabled */
st->scale_tbl[0][0] = tmp0; /* Integer part */
st->scale_tbl[0][1] = abs(tmp1); /* Fractional part */
/* Store scale for when span compression is enabled */
st->scale_tbl[1][0] = tmp0;
/* The integer part is always zero so don't bother to divide it. */
if (chan->differential)
st->scale_tbl[1][1] = DIV_ROUND_CLOSEST(abs(tmp1) * 4, 5);
else
st->scale_tbl[1][1] = DIV_ROUND_CLOSEST(abs(tmp1) * 9, 10);
}
static int ad4000_write_reg(struct ad4000_state *st, uint8_t val)
{
st->tx_buf[0] = AD4000_WRITE_COMMAND;
st->tx_buf[1] = val;
return spi_write(st->spi, st->tx_buf, ARRAY_SIZE(st->tx_buf));
}
static int ad4000_read_reg(struct ad4000_state *st, unsigned int *val)
{
struct spi_transfer t = {
.tx_buf = st->tx_buf,
.rx_buf = st->rx_buf,
.len = 2,
};
int ret;
st->tx_buf[0] = AD4000_READ_COMMAND;
ret = spi_sync_transfer(st->spi, &t, 1);
if (ret < 0)
return ret;
*val = st->rx_buf[1];
return ret;
}
static int ad4000_convert_and_acquire(struct ad4000_state *st)
{
int ret;
/*
* In 4-wire mode, the CNV line is held high for the entire conversion
* and acquisition process. In other modes, the CNV GPIO is optional
* and, if provided, replaces controller CS. If CNV GPIO is not defined
* gpiod_set_value_cansleep() has no effect.
*/
gpiod_set_value_cansleep(st->cnv_gpio, 1);
ret = spi_sync(st->spi, &st->msg);
gpiod_set_value_cansleep(st->cnv_gpio, 0);
return ret;
}
static int ad4000_single_conversion(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan, int *val)
{
struct ad4000_state *st = iio_priv(indio_dev);
u32 sample;
int ret;
ret = ad4000_convert_and_acquire(st);
if (ret < 0)
return ret;
if (chan->scan_type.storagebits > 16)
sample = be32_to_cpu(st->scan.data.sample_buf32);
else
sample = be16_to_cpu(st->scan.data.sample_buf16);
sample >>= chan->scan_type.shift;
if (chan->scan_type.sign == 's')
*val = sign_extend32(sample, chan->scan_type.realbits - 1);
else
*val = sample;
return IIO_VAL_INT;
}
static int ad4000_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan, int *val,
int *val2, long info)
{
struct ad4000_state *st = iio_priv(indio_dev);
int ret;
switch (info) {
case IIO_CHAN_INFO_RAW:
if (!iio_device_claim_direct(indio_dev))
return -EBUSY;
ret = ad4000_single_conversion(indio_dev, chan, val);
iio_device_release_direct(indio_dev);
return ret;
case IIO_CHAN_INFO_SCALE:
*val = st->scale_tbl[st->span_comp][0];
*val2 = st->scale_tbl[st->span_comp][1];
return IIO_VAL_INT_PLUS_NANO;
case IIO_CHAN_INFO_OFFSET:
*val = 0;
if (st->span_comp)
*val = mult_frac(st->vref_mv, 1, 10);
return IIO_VAL_INT;
default:
return -EINVAL;
}
}
static int ad4000_read_avail(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
const int **vals, int *type, int *length,
long info)
{
struct ad4000_state *st = iio_priv(indio_dev);
switch (info) {
case IIO_CHAN_INFO_SCALE:
*vals = (int *)st->scale_tbl;
*length = AD4000_SCALE_OPTIONS * 2;
*type = IIO_VAL_INT_PLUS_NANO;
return IIO_AVAIL_LIST;
default:
return -EINVAL;
}
}
static int ad4000_write_raw_get_fmt(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan, long mask)
{
switch (mask) {
case IIO_CHAN_INFO_SCALE:
return IIO_VAL_INT_PLUS_NANO;
default:
return IIO_VAL_INT_PLUS_MICRO;
}
}
static int __ad4000_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val2)
{
struct ad4000_state *st = iio_priv(indio_dev);
unsigned int reg_val;
bool span_comp_en;
int ret;
guard(mutex)(&st->lock);
ret = ad4000_read_reg(st, ®_val);
if (ret < 0)
return ret;
span_comp_en = val2 == st->scale_tbl[1][1];
reg_val &= ~AD4000_CFG_SPAN_COMP;
reg_val |= FIELD_PREP(AD4000_CFG_SPAN_COMP, span_comp_en);
ret = ad4000_write_reg(st, reg_val);
if (ret < 0)
return ret;
st->span_comp = span_comp_en;
return 0;
}
static int ad4000_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val, int val2, long mask)
{
int ret;
switch (mask) {
case IIO_CHAN_INFO_SCALE:
if (!iio_device_claim_direct(indio_dev))
return -EBUSY;
ret = __ad4000_write_raw(indio_dev, chan, val2);
iio_device_release_direct(indio_dev);
return ret;
default:
return -EINVAL;
}
}
static irqreturn_t ad4000_trigger_handler(int irq, void *p)
{
struct iio_poll_func *pf = p;
struct iio_dev *indio_dev = pf->indio_dev;
struct ad4000_state *st = iio_priv(indio_dev);
int ret;
ret = ad4000_convert_and_acquire(st);
if (ret < 0)
goto err_out;
iio_push_to_buffers_with_timestamp(indio_dev, &st->scan, pf->timestamp);
err_out:
iio_trigger_notify_done(indio_dev->trig);
return IRQ_HANDLED;
}
static const struct iio_info ad4000_reg_access_info = {
.read_raw = &ad4000_read_raw,
.read_avail = &ad4000_read_avail,
.write_raw = &ad4000_write_raw,
.write_raw_get_fmt = &ad4000_write_raw_get_fmt,
};
static const struct iio_info ad4000_info = {
.read_raw = &ad4000_read_raw,
};
/*
* This executes a data sample transfer for when the device connections are
* in "3-wire" mode, selected when the adi,sdi-pin device tree property is
* absent or set to "high". In this connection mode, the ADC SDI pin is
* connected to MOSI or to VIO and ADC CNV pin is connected either to a SPI
* controller CS or to a GPIO.
* AD4000 series of devices initiate conversions on the rising edge of CNV pin.
*
* If the CNV pin is connected to an SPI controller CS line (which is by default
* active low), the ADC readings would have a latency (delay) of one read.
* Moreover, since we also do ADC sampling for filling the buffer on triggered
* buffer mode, the timestamps of buffer readings would be disarranged.
* To prevent the read latency and reduce the time discrepancy between the
* sample read request and the time of actual sampling by the ADC, do a
* preparatory transfer to pulse the CS/CNV line.
*/
static int ad4000_prepare_3wire_mode_message(struct ad4000_state *st,
const struct iio_chan_spec *chan)
{
struct spi_transfer *xfers = st->xfers;
xfers[0].cs_change = 1;
xfers[0].cs_change_delay.value = st->time_spec->t_conv_ns;
xfers[0].cs_change_delay.unit = SPI_DELAY_UNIT_NSECS;
xfers[1].rx_buf = &st->scan.data;
xfers[1].len = BITS_TO_BYTES(chan->scan_type.storagebits);
xfers[1].delay.value = st->time_spec->t_quiet2_ns;
xfers[1].delay.unit = SPI_DELAY_UNIT_NSECS;
spi_message_init_with_transfers(&st->msg, st->xfers, 2);
return devm_spi_optimize_message(&st->spi->dev, st->spi, &st->msg);
}
/*
* This executes a data sample transfer for when the device connections are
* in "4-wire" mode, selected when the adi,sdi-pin device tree property is
* set to "cs". In this connection mode, the controller CS pin is connected to
* ADC SDI pin and a GPIO is connected to ADC CNV pin.
* The GPIO connected to ADC CNV pin is set outside of the SPI transfer.
*/
static int ad4000_prepare_4wire_mode_message(struct ad4000_state *st,
const struct iio_chan_spec *chan)
{
struct spi_transfer *xfers = st->xfers;
/*
* Dummy transfer to cause enough delay between CNV going high and SDI
* going low.
*/
xfers[0].cs_off = 1;
xfers[0].delay.value = st->time_spec->t_conv_ns;
xfers[0].delay.unit = SPI_DELAY_UNIT_NSECS;
xfers[1].rx_buf = &st->scan.data;
xfers[1].len = BITS_TO_BYTES(chan->scan_type.storagebits);
spi_message_init_with_transfers(&st->msg, st->xfers, 2);
return devm_spi_optimize_message(&st->spi->dev, st->spi, &st->msg);
}
static int ad4000_config(struct ad4000_state *st)
{
unsigned int reg_val = AD4000_CONFIG_REG_DEFAULT;
if (device_property_present(&st->spi->dev, "adi,high-z-input"))
reg_val |= FIELD_PREP(AD4000_CFG_HIGHZ, 1);
return ad4000_write_reg(st, reg_val);
}
static int ad4000_probe(struct spi_device *spi)
{
const struct ad4000_chip_info *chip;
struct device *dev = &spi->dev;
struct iio_dev *indio_dev;
struct ad4000_state *st;
int gain_idx, ret;
indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
if (!indio_dev)
return -ENOMEM;
chip = spi_get_device_match_data(spi);
if (!chip)
return -EINVAL;
st = iio_priv(indio_dev);
st->spi = spi;
st->time_spec = chip->time_spec;
ret = devm_regulator_bulk_get_enable(dev, ARRAY_SIZE(ad4000_power_supplies),
ad4000_power_supplies);
if (ret)
return dev_err_probe(dev, ret, "Failed to enable power supplies\n");
ret = devm_regulator_get_enable_read_voltage(dev, "ref");
if (ret < 0)
return dev_err_probe(dev, ret,
"Failed to get ref regulator reference\n");
st->vref_mv = ret / 1000;
st->cnv_gpio = devm_gpiod_get_optional(dev, "cnv", GPIOD_OUT_HIGH);
if (IS_ERR(st->cnv_gpio))
return dev_err_probe(dev, PTR_ERR(st->cnv_gpio),
"Failed to get CNV GPIO");
ret = device_property_match_property_string(dev, "adi,sdi-pin",
ad4000_sdi_pin,
ARRAY_SIZE(ad4000_sdi_pin));
if (ret < 0 && ret != -EINVAL)
return dev_err_probe(dev, ret,
"getting adi,sdi-pin property failed\n");
/* Default to usual SPI connections if pin properties are not present */
st->sdi_pin = ret == -EINVAL ? AD4000_SDI_MOSI : ret;
switch (st->sdi_pin) {
case AD4000_SDI_MOSI:
indio_dev->info = &ad4000_reg_access_info;
indio_dev->channels = chip->reg_access_chan_spec;
/*
* In "3-wire mode", the ADC SDI line must be kept high when
* data is not being clocked out of the controller.
* Request the SPI controller to make MOSI idle high.
*/
spi->mode |= SPI_MOSI_IDLE_HIGH;
ret = spi_setup(spi);
if (ret < 0)
return ret;
ret = ad4000_prepare_3wire_mode_message(st, &indio_dev->channels[0]);
if (ret)
return ret;
ret = ad4000_config(st);
if (ret < 0)
return dev_err_probe(dev, ret, "Failed to config device\n");
break;
case AD4000_SDI_VIO:
indio_dev->info = &ad4000_info;
indio_dev->channels = chip->chan_spec;
ret = ad4000_prepare_3wire_mode_message(st, &indio_dev->channels[0]);
if (ret)
return ret;
break;
case AD4000_SDI_CS:
indio_dev->info = &ad4000_info;
indio_dev->channels = chip->chan_spec;
ret = ad4000_prepare_4wire_mode_message(st, &indio_dev->channels[0]);
if (ret)
return ret;
break;
case AD4000_SDI_GND:
return dev_err_probe(dev, -EPROTONOSUPPORT,
"Unsupported connection mode\n");
default:
return dev_err_probe(dev, -EINVAL, "Unrecognized connection mode\n");
}
indio_dev->name = chip->dev_name;
indio_dev->num_channels = 2;
ret = devm_mutex_init(dev, &st->lock);
if (ret)
return ret;
st->gain_milli = 1000;
if (chip->has_hardware_gain) {
ret = device_property_read_u16(dev, "adi,gain-milli",
&st->gain_milli);
if (!ret) {
/* Match gain value from dt to one of supported gains */
gain_idx = find_closest(st->gain_milli, ad4000_gains,
ARRAY_SIZE(ad4000_gains));
st->gain_milli = ad4000_gains[gain_idx];
} else {
return dev_err_probe(dev, ret,
"Failed to read gain property\n");
}
}
ad4000_fill_scale_tbl(st, &indio_dev->channels[0]);
ret = devm_iio_triggered_buffer_setup(dev, indio_dev,
&iio_pollfunc_store_time,
&ad4000_trigger_handler, NULL);
if (ret)
return ret;
return devm_iio_device_register(dev, indio_dev);
}
static const struct spi_device_id ad4000_id[] = {
{ "ad4000", (kernel_ulong_t)&ad4000_chip_info },
{ "ad4001", (kernel_ulong_t)&ad4001_chip_info },
{ "ad4002", (kernel_ulong_t)&ad4002_chip_info },
{ "ad4003", (kernel_ulong_t)&ad4003_chip_info },
{ "ad4004", (kernel_ulong_t)&ad4004_chip_info },
{ "ad4005", (kernel_ulong_t)&ad4005_chip_info },
{ "ad4006", (kernel_ulong_t)&ad4006_chip_info },
{ "ad4007", (kernel_ulong_t)&ad4007_chip_info },
{ "ad4008", (kernel_ulong_t)&ad4008_chip_info },
{ "ad4010", (kernel_ulong_t)&ad4010_chip_info },
{ "ad4011", (kernel_ulong_t)&ad4011_chip_info },
{ "ad4020", (kernel_ulong_t)&ad4020_chip_info },
{ "ad4021", (kernel_ulong_t)&ad4021_chip_info },
{ "ad4022", (kernel_ulong_t)&ad4022_chip_info },
{ "adaq4001", (kernel_ulong_t)&adaq4001_chip_info },
{ "adaq4003", (kernel_ulong_t)&adaq4003_chip_info },
{ "ad7685", (kernel_ulong_t)&ad7685_chip_info },
{ "ad7686", (kernel_ulong_t)&ad7686_chip_info },
{ "ad7687", (kernel_ulong_t)&ad7687_chip_info },
{ "ad7688", (kernel_ulong_t)&ad7688_chip_info },
{ "ad7690", (kernel_ulong_t)&ad7690_chip_info },
{ "ad7691", (kernel_ulong_t)&ad7691_chip_info },
{ "ad7693", (kernel_ulong_t)&ad7693_chip_info },
{ "ad7942", (kernel_ulong_t)&ad7942_chip_info },
{ "ad7946", (kernel_ulong_t)&ad7946_chip_info },
{ "ad7980", (kernel_ulong_t)&ad7980_chip_info },
{ "ad7982", (kernel_ulong_t)&ad7982_chip_info },
{ "ad7983", (kernel_ulong_t)&ad7983_chip_info },
{ "ad7984", (kernel_ulong_t)&ad7984_chip_info },
{ "ad7988-1", (kernel_ulong_t)&ad7988_1_chip_info },
{ "ad7988-5", (kernel_ulong_t)&ad7988_5_chip_info },
{ }
};
MODULE_DEVICE_TABLE(spi, ad4000_id);
static const struct of_device_id ad4000_of_match[] = {
{ .compatible = "adi,ad4000", .data = &ad4000_chip_info },
{ .compatible = "adi,ad4001", .data = &ad4001_chip_info },
{ .compatible = "adi,ad4002", .data = &ad4002_chip_info },
{ .compatible = "adi,ad4003", .data = &ad4003_chip_info },
{ .compatible = "adi,ad4004", .data = &ad4004_chip_info },
{ .compatible = "adi,ad4005", .data = &ad4005_chip_info },
{ .compatible = "adi,ad4006", .data = &ad4006_chip_info },
{ .compatible = "adi,ad4007", .data = &ad4007_chip_info },
{ .compatible = "adi,ad4008", .data = &ad4008_chip_info },
{ .compatible = "adi,ad4010", .data = &ad4010_chip_info },
{ .compatible = "adi,ad4011", .data = &ad4011_chip_info },
{ .compatible = "adi,ad4020", .data = &ad4020_chip_info },
{ .compatible = "adi,ad4021", .data = &ad4021_chip_info },
{ .compatible = "adi,ad4022", .data = &ad4022_chip_info },
{ .compatible = "adi,adaq4001", .data = &adaq4001_chip_info },
{ .compatible = "adi,adaq4003", .data = &adaq4003_chip_info },
{ .compatible = "adi,ad7685", .data = &ad7685_chip_info },
{ .compatible = "adi,ad7686", .data = &ad7686_chip_info },
{ .compatible = "adi,ad7687", .data = &ad7687_chip_info },
{ .compatible = "adi,ad7688", .data = &ad7688_chip_info },
{ .compatible = "adi,ad7690", .data = &ad7690_chip_info },
{ .compatible = "adi,ad7691", .data = &ad7691_chip_info },
{ .compatible = "adi,ad7693", .data = &ad7693_chip_info },
{ .compatible = "adi,ad7942", .data = &ad7942_chip_info },
{ .compatible = "adi,ad7946", .data = &ad7946_chip_info },
{ .compatible = "adi,ad7980", .data = &ad7980_chip_info },
{ .compatible = "adi,ad7982", .data = &ad7982_chip_info },
{ .compatible = "adi,ad7983", .data = &ad7983_chip_info },
{ .compatible = "adi,ad7984", .data = &ad7984_chip_info },
{ .compatible = "adi,ad7988-1", .data = &ad7988_1_chip_info },
{ .compatible = "adi,ad7988-5", .data = &ad7988_5_chip_info },
{ }
};
MODULE_DEVICE_TABLE(of, ad4000_of_match);
static struct spi_driver ad4000_driver = {
.driver = {
.name = "ad4000",
.of_match_table = ad4000_of_match,
},
.probe = ad4000_probe,
.id_table = ad4000_id,
};
module_spi_driver(ad4000_driver);
MODULE_AUTHOR("Marcelo Schmitt <marcelo.schmitt@analog.com>");
MODULE_DESCRIPTION("Analog Devices AD4000 ADC driver");
MODULE_LICENSE("GPL");