// SPDX-License-Identifier: GPL-2.0-only
/*
* Analog Devices AD738x Simultaneous Sampling SAR ADCs
*
* Copyright 2017 Analog Devices Inc.
* Copyright 2024 BayLibre, SAS
*
* Datasheets of supported parts:
* ad7380/1 : https://www.analog.com/media/en/technical-documentation/data-sheets/AD7380-7381.pdf
* ad7383/4 : https://www.analog.com/media/en/technical-documentation/data-sheets/ad7383-7384.pdf
* ad7386/7/8 : https://www.analog.com/media/en/technical-documentation/data-sheets/AD7386-7387-7388.pdf
* ad7380-4 : https://www.analog.com/media/en/technical-documentation/data-sheets/ad7380-4.pdf
* ad7381-4 : https://www.analog.com/media/en/technical-documentation/data-sheets/ad7381-4.pdf
* ad7383/4-4 : https://www.analog.com/media/en/technical-documentation/data-sheets/ad7383-4-ad7384-4.pdf
* ad7386/7/8-4 : https://www.analog.com/media/en/technical-documentation/data-sheets/ad7386-4-7387-4-7388-4.pdf
*/
#include <linux/align.h>
#include <linux/bitfield.h>
#include <linux/bitops.h>
#include <linux/cleanup.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>
#include <linux/slab.h>
#include <linux/spi/spi.h>
#include <linux/iio/buffer.h>
#include <linux/iio/iio.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>
#define MAX_NUM_CHANNELS 8
/* 2.5V internal reference voltage */
#define AD7380_INTERNAL_REF_MV 2500
/* reading and writing registers is more reliable at lower than max speed */
#define AD7380_REG_WR_SPEED_HZ 10000000
#define AD7380_REG_WR BIT(15)
#define AD7380_REG_REGADDR GENMASK(14, 12)
#define AD7380_REG_DATA GENMASK(11, 0)
#define AD7380_REG_ADDR_NOP 0x0
#define AD7380_REG_ADDR_CONFIG1 0x1
#define AD7380_REG_ADDR_CONFIG2 0x2
#define AD7380_REG_ADDR_ALERT 0x3
#define AD7380_REG_ADDR_ALERT_LOW_TH 0x4
#define AD7380_REG_ADDR_ALERT_HIGH_TH 0x5
#define AD7380_CONFIG1_CH BIT(11)
#define AD7380_CONFIG1_SEQ BIT(10)
#define AD7380_CONFIG1_OS_MODE BIT(9)
#define AD7380_CONFIG1_OSR GENMASK(8, 6)
#define AD7380_CONFIG1_CRC_W BIT(5)
#define AD7380_CONFIG1_CRC_R BIT(4)
#define AD7380_CONFIG1_ALERTEN BIT(3)
#define AD7380_CONFIG1_RES BIT(2)
#define AD7380_CONFIG1_REFSEL BIT(1)
#define AD7380_CONFIG1_PMODE BIT(0)
#define AD7380_CONFIG2_SDO2 GENMASK(9, 8)
#define AD7380_CONFIG2_SDO BIT(8)
#define AD7380_CONFIG2_RESET GENMASK(7, 0)
#define AD7380_CONFIG2_RESET_SOFT 0x3C
#define AD7380_CONFIG2_RESET_HARD 0xFF
#define AD7380_ALERT_LOW_TH GENMASK(11, 0)
#define AD7380_ALERT_HIGH_TH GENMASK(11, 0)
#define T_CONVERT_NS 190 /* conversion time */
#define T_CONVERT_0_NS 10 /* 1st conversion start time (oversampling) */
#define T_CONVERT_X_NS 500 /* xth conversion start time (oversampling) */
struct ad7380_timing_specs {
const unsigned int t_csh_ns; /* CS minimum high time */
};
struct ad7380_chip_info {
const char *name;
const struct iio_chan_spec *channels;
unsigned int num_channels;
unsigned int num_simult_channels;
bool has_mux;
const char * const *vcm_supplies;
unsigned int num_vcm_supplies;
const unsigned long *available_scan_masks;
const struct ad7380_timing_specs *timing_specs;
};
enum {
AD7380_SCAN_TYPE_NORMAL,
AD7380_SCAN_TYPE_RESOLUTION_BOOST,
};
/* Extended scan types for 12-bit unsigned chips. */
static const struct iio_scan_type ad7380_scan_type_12_u[] = {
[AD7380_SCAN_TYPE_NORMAL] = {
.sign = 'u',
.realbits = 12,
.storagebits = 16,
.endianness = IIO_CPU,
},
[AD7380_SCAN_TYPE_RESOLUTION_BOOST] = {
.sign = 'u',
.realbits = 14,
.storagebits = 16,
.endianness = IIO_CPU,
},
};
/* Extended scan types for 14-bit signed chips. */
static const struct iio_scan_type ad7380_scan_type_14_s[] = {
[AD7380_SCAN_TYPE_NORMAL] = {
.sign = 's',
.realbits = 14,
.storagebits = 16,
.endianness = IIO_CPU,
},
[AD7380_SCAN_TYPE_RESOLUTION_BOOST] = {
.sign = 's',
.realbits = 16,
.storagebits = 16,
.endianness = IIO_CPU,
},
};
/* Extended scan types for 14-bit unsigned chips. */
static const struct iio_scan_type ad7380_scan_type_14_u[] = {
[AD7380_SCAN_TYPE_NORMAL] = {
.sign = 'u',
.realbits = 14,
.storagebits = 16,
.endianness = IIO_CPU,
},
[AD7380_SCAN_TYPE_RESOLUTION_BOOST] = {
.sign = 'u',
.realbits = 16,
.storagebits = 16,
.endianness = IIO_CPU,
},
};
/* Extended scan types for 16-bit signed_chips. */
static const struct iio_scan_type ad7380_scan_type_16_s[] = {
[AD7380_SCAN_TYPE_NORMAL] = {
.sign = 's',
.realbits = 16,
.storagebits = 16,
.endianness = IIO_CPU,
},
[AD7380_SCAN_TYPE_RESOLUTION_BOOST] = {
.sign = 's',
.realbits = 18,
.storagebits = 32,
.endianness = IIO_CPU,
},
};
/* Extended scan types for 16-bit unsigned chips. */
static const struct iio_scan_type ad7380_scan_type_16_u[] = {
[AD7380_SCAN_TYPE_NORMAL] = {
.sign = 'u',
.realbits = 16,
.storagebits = 16,
.endianness = IIO_CPU,
},
[AD7380_SCAN_TYPE_RESOLUTION_BOOST] = {
.sign = 'u',
.realbits = 18,
.storagebits = 32,
.endianness = IIO_CPU,
},
};
#define AD7380_CHANNEL(index, bits, diff, sign) { \
.type = IIO_VOLTAGE, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
((diff) ? 0 : BIT(IIO_CHAN_INFO_OFFSET)), \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \
BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
.info_mask_shared_by_type_available = \
BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
.indexed = 1, \
.differential = (diff), \
.channel = (diff) ? (2 * (index)) : (index), \
.channel2 = (diff) ? (2 * (index) + 1) : 0, \
.scan_index = (index), \
.has_ext_scan_type = 1, \
.ext_scan_type = ad7380_scan_type_##bits##_##sign, \
.num_ext_scan_type = ARRAY_SIZE(ad7380_scan_type_##bits##_##sign), \
}
#define DEFINE_AD7380_2_CHANNEL(name, bits, diff, sign) \
static const struct iio_chan_spec name[] = { \
AD7380_CHANNEL(0, bits, diff, sign), \
AD7380_CHANNEL(1, bits, diff, sign), \
IIO_CHAN_SOFT_TIMESTAMP(2), \
}
#define DEFINE_AD7380_4_CHANNEL(name, bits, diff, sign) \
static const struct iio_chan_spec name[] = { \
AD7380_CHANNEL(0, bits, diff, sign), \
AD7380_CHANNEL(1, bits, diff, sign), \
AD7380_CHANNEL(2, bits, diff, sign), \
AD7380_CHANNEL(3, bits, diff, sign), \
IIO_CHAN_SOFT_TIMESTAMP(4), \
}
#define DEFINE_AD7380_8_CHANNEL(name, bits, diff, sign) \
static const struct iio_chan_spec name[] = { \
AD7380_CHANNEL(0, bits, diff, sign), \
AD7380_CHANNEL(1, bits, diff, sign), \
AD7380_CHANNEL(2, bits, diff, sign), \
AD7380_CHANNEL(3, bits, diff, sign), \
AD7380_CHANNEL(4, bits, diff, sign), \
AD7380_CHANNEL(5, bits, diff, sign), \
AD7380_CHANNEL(6, bits, diff, sign), \
AD7380_CHANNEL(7, bits, diff, sign), \
IIO_CHAN_SOFT_TIMESTAMP(8), \
}
/* fully differential */
DEFINE_AD7380_2_CHANNEL(ad7380_channels, 16, 1, s);
DEFINE_AD7380_2_CHANNEL(ad7381_channels, 14, 1, s);
DEFINE_AD7380_4_CHANNEL(ad7380_4_channels, 16, 1, s);
DEFINE_AD7380_4_CHANNEL(ad7381_4_channels, 14, 1, s);
/* pseudo differential */
DEFINE_AD7380_2_CHANNEL(ad7383_channels, 16, 0, s);
DEFINE_AD7380_2_CHANNEL(ad7384_channels, 14, 0, s);
DEFINE_AD7380_4_CHANNEL(ad7383_4_channels, 16, 0, s);
DEFINE_AD7380_4_CHANNEL(ad7384_4_channels, 14, 0, s);
/* Single ended */
DEFINE_AD7380_4_CHANNEL(ad7386_channels, 16, 0, u);
DEFINE_AD7380_4_CHANNEL(ad7387_channels, 14, 0, u);
DEFINE_AD7380_4_CHANNEL(ad7388_channels, 12, 0, u);
DEFINE_AD7380_8_CHANNEL(ad7386_4_channels, 16, 0, u);
DEFINE_AD7380_8_CHANNEL(ad7387_4_channels, 14, 0, u);
DEFINE_AD7380_8_CHANNEL(ad7388_4_channels, 12, 0, u);
static const char * const ad7380_2_channel_vcm_supplies[] = {
"aina", "ainb",
};
static const char * const ad7380_4_channel_vcm_supplies[] = {
"aina", "ainb", "ainc", "aind",
};
/* Since this is simultaneous sampling, we don't allow individual channels. */
static const unsigned long ad7380_2_channel_scan_masks[] = {
GENMASK(1, 0),
0
};
static const unsigned long ad7380_4_channel_scan_masks[] = {
GENMASK(3, 0),
0
};
/*
* Single ended parts have a 2:1 multiplexer in front of each ADC.
*
* From an IIO point of view, all inputs are exported, i.e ad7386/7/8
* export 4 channels and ad7386-4/7-4/8-4 export 8 channels.
*
* Inputs AinX0 of multiplexers correspond to the first half of IIO channels
* (i.e 0-1 or 0-3) and inputs AinX1 correspond to second half (i.e 2-3 or
* 4-7). Example for AD7386/7/8 (2 channels parts):
*
* IIO | AD7386/7/8
* | +----------------------------
* | | _____ ______
* | | | | | |
* voltage0 | AinA0 --|--->| | | |
* | | | mux |----->| ADCA |---
* voltage2 | AinA1 --|--->| | | |
* | | |_____| |_____ |
* | | _____ ______
* | | | | | |
* voltage1 | AinB0 --|--->| | | |
* | | | mux |----->| ADCB |---
* voltage3 | AinB1 --|--->| | | |
* | | |_____| |______|
* | |
* | +----------------------------
*
* Since this is simultaneous sampling for AinX0 OR AinX1 we have two separate
* scan masks.
* When sequencer mode is enabled, chip automatically cycles through
* AinX0 and AinX1 channels. From an IIO point of view, we ca enable all
* channels, at the cost of an extra read, thus dividing the maximum rate by
* two.
*/
enum {
AD7380_SCAN_MASK_CH_0,
AD7380_SCAN_MASK_CH_1,
AD7380_SCAN_MASK_SEQ,
};
static const unsigned long ad7380_2x2_channel_scan_masks[] = {
[AD7380_SCAN_MASK_CH_0] = GENMASK(1, 0),
[AD7380_SCAN_MASK_CH_1] = GENMASK(3, 2),
[AD7380_SCAN_MASK_SEQ] = GENMASK(3, 0),
0
};
static const unsigned long ad7380_2x4_channel_scan_masks[] = {
[AD7380_SCAN_MASK_CH_0] = GENMASK(3, 0),
[AD7380_SCAN_MASK_CH_1] = GENMASK(7, 4),
[AD7380_SCAN_MASK_SEQ] = GENMASK(7, 0),
0
};
static const struct ad7380_timing_specs ad7380_timing = {
.t_csh_ns = 10,
};
static const struct ad7380_timing_specs ad7380_4_timing = {
.t_csh_ns = 20,
};
/*
* Available oversampling ratios. The indices correspond with the bit value
* expected by the chip. The available ratios depend on the averaging mode,
* only normal averaging is supported for now.
*/
static const int ad7380_oversampling_ratios[] = {
1, 2, 4, 8, 16, 32,
};
static const struct ad7380_chip_info ad7380_chip_info = {
.name = "ad7380",
.channels = ad7380_channels,
.num_channels = ARRAY_SIZE(ad7380_channels),
.num_simult_channels = 2,
.available_scan_masks = ad7380_2_channel_scan_masks,
.timing_specs = &ad7380_timing,
};
static const struct ad7380_chip_info ad7381_chip_info = {
.name = "ad7381",
.channels = ad7381_channels,
.num_channels = ARRAY_SIZE(ad7381_channels),
.num_simult_channels = 2,
.available_scan_masks = ad7380_2_channel_scan_masks,
.timing_specs = &ad7380_timing,
};
static const struct ad7380_chip_info ad7383_chip_info = {
.name = "ad7383",
.channels = ad7383_channels,
.num_channels = ARRAY_SIZE(ad7383_channels),
.num_simult_channels = 2,
.vcm_supplies = ad7380_2_channel_vcm_supplies,
.num_vcm_supplies = ARRAY_SIZE(ad7380_2_channel_vcm_supplies),
.available_scan_masks = ad7380_2_channel_scan_masks,
.timing_specs = &ad7380_timing,
};
static const struct ad7380_chip_info ad7384_chip_info = {
.name = "ad7384",
.channels = ad7384_channels,
.num_channels = ARRAY_SIZE(ad7384_channels),
.num_simult_channels = 2,
.vcm_supplies = ad7380_2_channel_vcm_supplies,
.num_vcm_supplies = ARRAY_SIZE(ad7380_2_channel_vcm_supplies),
.available_scan_masks = ad7380_2_channel_scan_masks,
.timing_specs = &ad7380_timing,
};
static const struct ad7380_chip_info ad7386_chip_info = {
.name = "ad7386",
.channels = ad7386_channels,
.num_channels = ARRAY_SIZE(ad7386_channels),
.num_simult_channels = 2,
.has_mux = true,
.available_scan_masks = ad7380_2x2_channel_scan_masks,
.timing_specs = &ad7380_timing,
};
static const struct ad7380_chip_info ad7387_chip_info = {
.name = "ad7387",
.channels = ad7387_channels,
.num_channels = ARRAY_SIZE(ad7387_channels),
.num_simult_channels = 2,
.has_mux = true,
.available_scan_masks = ad7380_2x2_channel_scan_masks,
.timing_specs = &ad7380_timing,
};
static const struct ad7380_chip_info ad7388_chip_info = {
.name = "ad7388",
.channels = ad7388_channels,
.num_channels = ARRAY_SIZE(ad7388_channels),
.num_simult_channels = 2,
.has_mux = true,
.available_scan_masks = ad7380_2x2_channel_scan_masks,
.timing_specs = &ad7380_timing,
};
static const struct ad7380_chip_info ad7380_4_chip_info = {
.name = "ad7380-4",
.channels = ad7380_4_channels,
.num_channels = ARRAY_SIZE(ad7380_4_channels),
.num_simult_channels = 4,
.available_scan_masks = ad7380_4_channel_scan_masks,
.timing_specs = &ad7380_4_timing,
};
static const struct ad7380_chip_info ad7381_4_chip_info = {
.name = "ad7381-4",
.channels = ad7381_4_channels,
.num_channels = ARRAY_SIZE(ad7381_4_channels),
.num_simult_channels = 4,
.available_scan_masks = ad7380_4_channel_scan_masks,
.timing_specs = &ad7380_4_timing,
};
static const struct ad7380_chip_info ad7383_4_chip_info = {
.name = "ad7383-4",
.channels = ad7383_4_channels,
.num_channels = ARRAY_SIZE(ad7383_4_channels),
.num_simult_channels = 4,
.vcm_supplies = ad7380_4_channel_vcm_supplies,
.num_vcm_supplies = ARRAY_SIZE(ad7380_4_channel_vcm_supplies),
.available_scan_masks = ad7380_4_channel_scan_masks,
.timing_specs = &ad7380_4_timing,
};
static const struct ad7380_chip_info ad7384_4_chip_info = {
.name = "ad7384-4",
.channels = ad7384_4_channels,
.num_channels = ARRAY_SIZE(ad7384_4_channels),
.num_simult_channels = 4,
.vcm_supplies = ad7380_4_channel_vcm_supplies,
.num_vcm_supplies = ARRAY_SIZE(ad7380_4_channel_vcm_supplies),
.available_scan_masks = ad7380_4_channel_scan_masks,
.timing_specs = &ad7380_4_timing,
};
static const struct ad7380_chip_info ad7386_4_chip_info = {
.name = "ad7386-4",
.channels = ad7386_4_channels,
.num_channels = ARRAY_SIZE(ad7386_4_channels),
.num_simult_channels = 4,
.has_mux = true,
.available_scan_masks = ad7380_2x4_channel_scan_masks,
.timing_specs = &ad7380_4_timing,
};
static const struct ad7380_chip_info ad7387_4_chip_info = {
.name = "ad7387-4",
.channels = ad7387_4_channels,
.num_channels = ARRAY_SIZE(ad7387_4_channels),
.num_simult_channels = 4,
.has_mux = true,
.available_scan_masks = ad7380_2x4_channel_scan_masks,
.timing_specs = &ad7380_4_timing,
};
static const struct ad7380_chip_info ad7388_4_chip_info = {
.name = "ad7388-4",
.channels = ad7388_4_channels,
.num_channels = ARRAY_SIZE(ad7388_4_channels),
.num_simult_channels = 4,
.has_mux = true,
.available_scan_masks = ad7380_2x4_channel_scan_masks,
.timing_specs = &ad7380_4_timing,
};
struct ad7380_state {
const struct ad7380_chip_info *chip_info;
struct spi_device *spi;
struct regmap *regmap;
unsigned int oversampling_ratio;
bool resolution_boost_enabled;
unsigned int ch;
bool seq;
unsigned int vref_mv;
unsigned int vcm_mv[MAX_NUM_CHANNELS];
/* xfers, message an buffer for reading sample data */
struct spi_transfer normal_xfer[2];
struct spi_message normal_msg;
struct spi_transfer seq_xfer[4];
struct spi_message seq_msg;
/*
* DMA (thus cache coherency maintenance) requires the transfer buffers
* to live in their own cache lines.
*
* Make the buffer large enough for MAX_NUM_CHANNELS 32-bit samples and
* one 64-bit aligned 64-bit timestamp.
*/
u8 scan_data[ALIGN(MAX_NUM_CHANNELS * sizeof(u32), sizeof(s64))
+ sizeof(s64)] __aligned(IIO_DMA_MINALIGN);
/* buffers for reading/writing registers */
u16 tx;
u16 rx;
};
static int ad7380_regmap_reg_write(void *context, unsigned int reg,
unsigned int val)
{
struct ad7380_state *st = context;
struct spi_transfer xfer = {
.speed_hz = AD7380_REG_WR_SPEED_HZ,
.bits_per_word = 16,
.len = 2,
.tx_buf = &st->tx,
};
st->tx = FIELD_PREP(AD7380_REG_WR, 1) |
FIELD_PREP(AD7380_REG_REGADDR, reg) |
FIELD_PREP(AD7380_REG_DATA, val);
return spi_sync_transfer(st->spi, &xfer, 1);
}
static int ad7380_regmap_reg_read(void *context, unsigned int reg,
unsigned int *val)
{
struct ad7380_state *st = context;
struct spi_transfer xfers[] = {
{
.speed_hz = AD7380_REG_WR_SPEED_HZ,
.bits_per_word = 16,
.len = 2,
.tx_buf = &st->tx,
.cs_change = 1,
.cs_change_delay = {
.value = st->chip_info->timing_specs->t_csh_ns,
.unit = SPI_DELAY_UNIT_NSECS,
},
}, {
.speed_hz = AD7380_REG_WR_SPEED_HZ,
.bits_per_word = 16,
.len = 2,
.rx_buf = &st->rx,
},
};
int ret;
st->tx = FIELD_PREP(AD7380_REG_WR, 0) |
FIELD_PREP(AD7380_REG_REGADDR, reg) |
FIELD_PREP(AD7380_REG_DATA, 0);
ret = spi_sync_transfer(st->spi, xfers, ARRAY_SIZE(xfers));
if (ret < 0)
return ret;
*val = FIELD_GET(AD7380_REG_DATA, st->rx);
return 0;
}
static const struct regmap_config ad7380_regmap_config = {
.reg_bits = 3,
.val_bits = 12,
.reg_read = ad7380_regmap_reg_read,
.reg_write = ad7380_regmap_reg_write,
.max_register = AD7380_REG_ADDR_ALERT_HIGH_TH,
.can_sleep = true,
};
static int ad7380_debugfs_reg_access(struct iio_dev *indio_dev, u32 reg,
u32 writeval, u32 *readval)
{
iio_device_claim_direct_scoped(return -EBUSY, indio_dev) {
struct ad7380_state *st = iio_priv(indio_dev);
if (readval)
return regmap_read(st->regmap, reg, readval);
else
return regmap_write(st->regmap, reg, writeval);
}
unreachable();
}
/*
* When switching channel, the ADC require an additional settling time.
* According to the datasheet, data is value on the third CS low. We already
* have an extra toggle before each read (either direct reads or buffered reads)
* to sample correct data, so we just add a single CS toggle at the end of the
* register write.
*/
static int ad7380_set_ch(struct ad7380_state *st, unsigned int ch)
{
struct spi_transfer xfer = {
.delay = {
.value = T_CONVERT_NS,
.unit = SPI_DELAY_UNIT_NSECS,
}
};
int ret;
if (st->ch == ch)
return 0;
ret = regmap_update_bits(st->regmap,
AD7380_REG_ADDR_CONFIG1,
AD7380_CONFIG1_CH,
FIELD_PREP(AD7380_CONFIG1_CH, ch));
if (ret)
return ret;
st->ch = ch;
if (st->oversampling_ratio > 1)
xfer.delay.value = T_CONVERT_0_NS +
T_CONVERT_X_NS * (st->oversampling_ratio - 1);
return spi_sync_transfer(st->spi, &xfer, 1);
}
/**
* ad7380_update_xfers - update the SPI transfers base on the current scan type
* @st: device instance specific state
* @scan_type: current scan type
*/
static void ad7380_update_xfers(struct ad7380_state *st,
const struct iio_scan_type *scan_type)
{
struct spi_transfer *xfer = st->seq ? st->seq_xfer : st->normal_xfer;
unsigned int t_convert = T_CONVERT_NS;
/*
* In the case of oversampling, conversion time is higher than in normal
* mode. Technically T_CONVERT_X_NS is lower for some chips, but we use
* the maximum value for simplicity for now.
*/
if (st->oversampling_ratio > 1)
t_convert = T_CONVERT_0_NS + T_CONVERT_X_NS *
(st->oversampling_ratio - 1);
if (st->seq) {
xfer[0].delay.value = xfer[1].delay.value = t_convert;
xfer[0].delay.unit = xfer[1].delay.unit = SPI_DELAY_UNIT_NSECS;
xfer[2].bits_per_word = xfer[3].bits_per_word =
scan_type->realbits;
xfer[2].len = xfer[3].len =
BITS_TO_BYTES(scan_type->storagebits) *
st->chip_info->num_simult_channels;
xfer[3].rx_buf = xfer[2].rx_buf + xfer[2].len;
/* Additional delay required here when oversampling is enabled */
if (st->oversampling_ratio > 1)
xfer[2].delay.value = t_convert;
else
xfer[2].delay.value = 0;
xfer[2].delay.unit = SPI_DELAY_UNIT_NSECS;
} else {
xfer[0].delay.value = t_convert;
xfer[0].delay.unit = SPI_DELAY_UNIT_NSECS;
xfer[1].bits_per_word = scan_type->realbits;
xfer[1].len = BITS_TO_BYTES(scan_type->storagebits) *
st->chip_info->num_simult_channels;
}
}
static int ad7380_triggered_buffer_preenable(struct iio_dev *indio_dev)
{
struct ad7380_state *st = iio_priv(indio_dev);
const struct iio_scan_type *scan_type;
struct spi_message *msg = &st->normal_msg;
/*
* Currently, we always read all channels at the same time. The scan_type
* is the same for all channels, so we just pass the first channel.
*/
scan_type = iio_get_current_scan_type(indio_dev, &indio_dev->channels[0]);
if (IS_ERR(scan_type))
return PTR_ERR(scan_type);
if (st->chip_info->has_mux) {
unsigned int index;
int ret;
/*
* Depending on the requested scan_mask and current state,
* we need to either change CH bit, or enable sequencer mode
* to sample correct data.
* Sequencer mode is enabled if active mask corresponds to all
* IIO channels enabled. Otherwise, CH bit is set.
*/
ret = iio_active_scan_mask_index(indio_dev);
if (ret < 0)
return ret;
index = ret;
if (index == AD7380_SCAN_MASK_SEQ) {
ret = regmap_update_bits(st->regmap,
AD7380_REG_ADDR_CONFIG1,
AD7380_CONFIG1_SEQ,
FIELD_PREP(AD7380_CONFIG1_SEQ, 1));
if (ret)
return ret;
msg = &st->seq_msg;
st->seq = true;
} else {
ret = ad7380_set_ch(st, index);
if (ret)
return ret;
}
}
ad7380_update_xfers(st, scan_type);
return spi_optimize_message(st->spi, msg);
}
static int ad7380_triggered_buffer_postdisable(struct iio_dev *indio_dev)
{
struct ad7380_state *st = iio_priv(indio_dev);
struct spi_message *msg = &st->normal_msg;
int ret;
if (st->seq) {
ret = regmap_update_bits(st->regmap,
AD7380_REG_ADDR_CONFIG1,
AD7380_CONFIG1_SEQ,
FIELD_PREP(AD7380_CONFIG1_SEQ, 0));
if (ret)
return ret;
msg = &st->seq_msg;
st->seq = false;
}
spi_unoptimize_message(msg);
return 0;
}
static const struct iio_buffer_setup_ops ad7380_buffer_setup_ops = {
.preenable = ad7380_triggered_buffer_preenable,
.postdisable = ad7380_triggered_buffer_postdisable,
};
static irqreturn_t ad7380_trigger_handler(int irq, void *p)
{
struct iio_poll_func *pf = p;
struct iio_dev *indio_dev = pf->indio_dev;
struct ad7380_state *st = iio_priv(indio_dev);
struct spi_message *msg = st->seq ? &st->seq_msg : &st->normal_msg;
int ret;
ret = spi_sync(st->spi, msg);
if (ret)
goto out;
iio_push_to_buffers_with_timestamp(indio_dev, &st->scan_data,
pf->timestamp);
out:
iio_trigger_notify_done(indio_dev->trig);
return IRQ_HANDLED;
}
static int ad7380_read_direct(struct ad7380_state *st, unsigned int scan_index,
const struct iio_scan_type *scan_type, int *val)
{
unsigned int index = scan_index;
int ret;
if (st->chip_info->has_mux) {
unsigned int ch = 0;
if (index >= st->chip_info->num_simult_channels) {
index -= st->chip_info->num_simult_channels;
ch = 1;
}
ret = ad7380_set_ch(st, ch);
if (ret)
return ret;
}
ad7380_update_xfers(st, scan_type);
ret = spi_sync(st->spi, &st->normal_msg);
if (ret < 0)
return ret;
if (scan_type->storagebits > 16) {
if (scan_type->sign == 's')
*val = sign_extend32(*(u32 *)(st->scan_data + 4 * index),
scan_type->realbits - 1);
else
*val = *(u32 *)(st->scan_data + 4 * index) &
GENMASK(scan_type->realbits - 1, 0);
} else {
if (scan_type->sign == 's')
*val = sign_extend32(*(u16 *)(st->scan_data + 2 * index),
scan_type->realbits - 1);
else
*val = *(u16 *)(st->scan_data + 2 * index) &
GENMASK(scan_type->realbits - 1, 0);
}
return IIO_VAL_INT;
}
static int ad7380_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long info)
{
struct ad7380_state *st = iio_priv(indio_dev);
const struct iio_scan_type *scan_type;
scan_type = iio_get_current_scan_type(indio_dev, chan);
if (IS_ERR(scan_type))
return PTR_ERR(scan_type);
switch (info) {
case IIO_CHAN_INFO_RAW:
iio_device_claim_direct_scoped(return -EBUSY, indio_dev) {
return ad7380_read_direct(st, chan->scan_index,
scan_type, val);
}
unreachable();
case IIO_CHAN_INFO_SCALE:
/*
* According to the datasheet, the LSB size is:
* * (2 × VREF) / 2^N, for differential chips
* * VREF / 2^N, for pseudo-differential chips
* where N is the ADC resolution (i.e realbits)
*/
*val = st->vref_mv;
*val2 = scan_type->realbits - chan->differential;
return IIO_VAL_FRACTIONAL_LOG2;
case IIO_CHAN_INFO_OFFSET:
/*
* According to IIO ABI, offset is applied before scale,
* so offset is: vcm_mv / scale
*/
*val = st->vcm_mv[chan->channel] * (1 << scan_type->realbits)
/ st->vref_mv;
return IIO_VAL_INT;
case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
*val = st->oversampling_ratio;
return IIO_VAL_INT;
default:
return -EINVAL;
}
}
static int ad7380_read_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_OVERSAMPLING_RATIO:
*vals = ad7380_oversampling_ratios;
*length = ARRAY_SIZE(ad7380_oversampling_ratios);
*type = IIO_VAL_INT;
return IIO_AVAIL_LIST;
default:
return -EINVAL;
}
}
/**
* ad7380_osr_to_regval - convert ratio to OSR register value
* @ratio: ratio to check
*
* Check if ratio is present in the list of available ratios and return the
* corresponding value that needs to be written to the register to select that
* ratio.
*
* Returns: register value (0 to 7) or -EINVAL if there is not an exact match
*/
static int ad7380_osr_to_regval(int ratio)
{
int i;
for (i = 0; i < ARRAY_SIZE(ad7380_oversampling_ratios); i++) {
if (ratio == ad7380_oversampling_ratios[i])
return i;
}
return -EINVAL;
}
static int ad7380_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan, int val,
int val2, long mask)
{
struct ad7380_state *st = iio_priv(indio_dev);
int ret, osr, boost;
switch (mask) {
case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
osr = ad7380_osr_to_regval(val);
if (osr < 0)
return osr;
/* always enable resolution boost when oversampling is enabled */
boost = osr > 0 ? 1 : 0;
iio_device_claim_direct_scoped(return -EBUSY, indio_dev) {
ret = regmap_update_bits(st->regmap,
AD7380_REG_ADDR_CONFIG1,
AD7380_CONFIG1_OSR | AD7380_CONFIG1_RES,
FIELD_PREP(AD7380_CONFIG1_OSR, osr) |
FIELD_PREP(AD7380_CONFIG1_RES, boost));
if (ret)
return ret;
st->oversampling_ratio = val;
st->resolution_boost_enabled = boost;
/*
* Perform a soft reset. This will flush the oversampling
* block and FIFO but will maintain the content of the
* configurable registers.
*/
return regmap_update_bits(st->regmap,
AD7380_REG_ADDR_CONFIG2,
AD7380_CONFIG2_RESET,
FIELD_PREP(AD7380_CONFIG2_RESET,
AD7380_CONFIG2_RESET_SOFT));
}
unreachable();
default:
return -EINVAL;
}
}
static int ad7380_get_current_scan_type(const struct iio_dev *indio_dev,
const struct iio_chan_spec *chan)
{
struct ad7380_state *st = iio_priv(indio_dev);
return st->resolution_boost_enabled ? AD7380_SCAN_TYPE_RESOLUTION_BOOST
: AD7380_SCAN_TYPE_NORMAL;
}
static const struct iio_info ad7380_info = {
.read_raw = &ad7380_read_raw,
.read_avail = &ad7380_read_avail,
.write_raw = &ad7380_write_raw,
.get_current_scan_type = &ad7380_get_current_scan_type,
.debugfs_reg_access = &ad7380_debugfs_reg_access,
};
static int ad7380_init(struct ad7380_state *st, struct regulator *vref)
{
int ret;
/* perform hard reset */
ret = regmap_update_bits(st->regmap, AD7380_REG_ADDR_CONFIG2,
AD7380_CONFIG2_RESET,
FIELD_PREP(AD7380_CONFIG2_RESET,
AD7380_CONFIG2_RESET_HARD));
if (ret < 0)
return ret;
/* select internal or external reference voltage */
ret = regmap_update_bits(st->regmap, AD7380_REG_ADDR_CONFIG1,
AD7380_CONFIG1_REFSEL,
FIELD_PREP(AD7380_CONFIG1_REFSEL,
vref ? 1 : 0));
if (ret < 0)
return ret;
/* This is the default value after reset. */
st->oversampling_ratio = 1;
st->ch = 0;
st->seq = false;
/* SPI 1-wire mode */
return regmap_update_bits(st->regmap, AD7380_REG_ADDR_CONFIG2,
AD7380_CONFIG2_SDO,
FIELD_PREP(AD7380_CONFIG2_SDO, 1));
}
static void ad7380_regulator_disable(void *p)
{
regulator_disable(p);
}
static int ad7380_probe(struct spi_device *spi)
{
struct iio_dev *indio_dev;
struct ad7380_state *st;
struct regulator *vref;
int ret, i;
indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
if (!indio_dev)
return -ENOMEM;
st = iio_priv(indio_dev);
st->spi = spi;
st->chip_info = spi_get_device_match_data(spi);
if (!st->chip_info)
return dev_err_probe(&spi->dev, -EINVAL, "missing match data\n");
vref = devm_regulator_get_optional(&spi->dev, "refio");
if (IS_ERR(vref)) {
if (PTR_ERR(vref) != -ENODEV)
return dev_err_probe(&spi->dev, PTR_ERR(vref),
"Failed to get refio regulator\n");
vref = NULL;
}
/*
* If there is no REFIO supply, then it means that we are using
* the internal 2.5V reference, otherwise REFIO is reference voltage.
*/
if (vref) {
ret = regulator_enable(vref);
if (ret)
return ret;
ret = devm_add_action_or_reset(&spi->dev,
ad7380_regulator_disable, vref);
if (ret)
return ret;
ret = regulator_get_voltage(vref);
if (ret < 0)
return ret;
st->vref_mv = ret / 1000;
} else {
st->vref_mv = AD7380_INTERNAL_REF_MV;
}
if (st->chip_info->num_vcm_supplies > ARRAY_SIZE(st->vcm_mv))
return dev_err_probe(&spi->dev, -EINVAL,
"invalid number of VCM supplies\n");
/*
* pseudo-differential chips have common mode supplies for the negative
* input pin.
*/
for (i = 0; i < st->chip_info->num_vcm_supplies; i++) {
struct regulator *vcm;
vcm = devm_regulator_get(&spi->dev,
st->chip_info->vcm_supplies[i]);
if (IS_ERR(vcm))
return dev_err_probe(&spi->dev, PTR_ERR(vcm),
"Failed to get %s regulator\n",
st->chip_info->vcm_supplies[i]);
ret = regulator_enable(vcm);
if (ret)
return ret;
ret = devm_add_action_or_reset(&spi->dev,
ad7380_regulator_disable, vcm);
if (ret)
return ret;
ret = regulator_get_voltage(vcm);
if (ret < 0)
return ret;
st->vcm_mv[i] = ret / 1000;
}
st->regmap = devm_regmap_init(&spi->dev, NULL, st, &ad7380_regmap_config);
if (IS_ERR(st->regmap))
return dev_err_probe(&spi->dev, PTR_ERR(st->regmap),
"failed to allocate register map\n");
/*
* Setting up xfer structures for both normal and sequence mode. These
* struct are used for both direct read and triggered buffer. Additional
* fields will be set up in ad7380_update_xfers() based on the current
* state of the driver at the time of the read.
*/
/*
* In normal mode a read is composed of two steps:
* - first, toggle CS (no data xfer) to trigger a conversion
* - then, read data
*/
st->normal_xfer[0].cs_change = 1;
st->normal_xfer[0].cs_change_delay.value = st->chip_info->timing_specs->t_csh_ns;
st->normal_xfer[0].cs_change_delay.unit = SPI_DELAY_UNIT_NSECS;
st->normal_xfer[1].rx_buf = st->scan_data;
spi_message_init_with_transfers(&st->normal_msg, st->normal_xfer,
ARRAY_SIZE(st->normal_xfer));
/*
* In sequencer mode a read is composed of four steps:
* - CS toggle (no data xfer) to get the right point in the sequence
* - CS toggle (no data xfer) to trigger a conversion of AinX0 and
* acquisition of AinX1
* - 2 data reads, to read AinX0 and AinX1
*/
st->seq_xfer[0].cs_change = 1;
st->seq_xfer[0].cs_change_delay.value = st->chip_info->timing_specs->t_csh_ns;
st->seq_xfer[0].cs_change_delay.unit = SPI_DELAY_UNIT_NSECS;
st->seq_xfer[1].cs_change = 1;
st->seq_xfer[1].cs_change_delay.value = st->chip_info->timing_specs->t_csh_ns;
st->seq_xfer[1].cs_change_delay.unit = SPI_DELAY_UNIT_NSECS;
st->seq_xfer[2].rx_buf = st->scan_data;
st->seq_xfer[2].cs_change = 1;
st->seq_xfer[2].cs_change_delay.value = st->chip_info->timing_specs->t_csh_ns;
st->seq_xfer[2].cs_change_delay.unit = SPI_DELAY_UNIT_NSECS;
spi_message_init_with_transfers(&st->seq_msg, st->seq_xfer,
ARRAY_SIZE(st->seq_xfer));
indio_dev->channels = st->chip_info->channels;
indio_dev->num_channels = st->chip_info->num_channels;
indio_dev->name = st->chip_info->name;
indio_dev->info = &ad7380_info;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->available_scan_masks = st->chip_info->available_scan_masks;
ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev,
iio_pollfunc_store_time,
ad7380_trigger_handler,
&ad7380_buffer_setup_ops);
if (ret)
return ret;
ret = ad7380_init(st, vref);
if (ret)
return ret;
return devm_iio_device_register(&spi->dev, indio_dev);
}
static const struct of_device_id ad7380_of_match_table[] = {
{ .compatible = "adi,ad7380", .data = &ad7380_chip_info },
{ .compatible = "adi,ad7381", .data = &ad7381_chip_info },
{ .compatible = "adi,ad7383", .data = &ad7383_chip_info },
{ .compatible = "adi,ad7384", .data = &ad7384_chip_info },
{ .compatible = "adi,ad7386", .data = &ad7386_chip_info },
{ .compatible = "adi,ad7387", .data = &ad7387_chip_info },
{ .compatible = "adi,ad7388", .data = &ad7388_chip_info },
{ .compatible = "adi,ad7380-4", .data = &ad7380_4_chip_info },
{ .compatible = "adi,ad7381-4", .data = &ad7381_4_chip_info },
{ .compatible = "adi,ad7383-4", .data = &ad7383_4_chip_info },
{ .compatible = "adi,ad7384-4", .data = &ad7384_4_chip_info },
{ .compatible = "adi,ad7386-4", .data = &ad7386_4_chip_info },
{ .compatible = "adi,ad7387-4", .data = &ad7387_4_chip_info },
{ .compatible = "adi,ad7388-4", .data = &ad7388_4_chip_info },
{ }
};
static const struct spi_device_id ad7380_id_table[] = {
{ "ad7380", (kernel_ulong_t)&ad7380_chip_info },
{ "ad7381", (kernel_ulong_t)&ad7381_chip_info },
{ "ad7383", (kernel_ulong_t)&ad7383_chip_info },
{ "ad7384", (kernel_ulong_t)&ad7384_chip_info },
{ "ad7386", (kernel_ulong_t)&ad7386_chip_info },
{ "ad7387", (kernel_ulong_t)&ad7387_chip_info },
{ "ad7388", (kernel_ulong_t)&ad7388_chip_info },
{ "ad7380-4", (kernel_ulong_t)&ad7380_4_chip_info },
{ "ad7381-4", (kernel_ulong_t)&ad7381_4_chip_info },
{ "ad7383-4", (kernel_ulong_t)&ad7383_4_chip_info },
{ "ad7384-4", (kernel_ulong_t)&ad7384_4_chip_info },
{ "ad7386-4", (kernel_ulong_t)&ad7386_4_chip_info },
{ "ad7387-4", (kernel_ulong_t)&ad7387_4_chip_info },
{ "ad7388-4", (kernel_ulong_t)&ad7388_4_chip_info },
{ }
};
MODULE_DEVICE_TABLE(spi, ad7380_id_table);
static struct spi_driver ad7380_driver = {
.driver = {
.name = "ad7380",
.of_match_table = ad7380_of_match_table,
},
.probe = ad7380_probe,
.id_table = ad7380_id_table,
};
module_spi_driver(ad7380_driver);
MODULE_AUTHOR("Stefan Popa <[email protected]>");
MODULE_DESCRIPTION("Analog Devices AD738x ADC driver");
MODULE_LICENSE("GPL");
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