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linux/drivers/iio/adc/ad4170-4.c
Marcelo Schmitt 6098df897d iio: adc: ad4170-4: Add support for weigh scale, thermocouple, and RTD sens 
The AD4170-4 design provides features to aid interfacing with weigh scales,
thermocouples, and RTD sensors, which are set up with additional circuitry
for proper sensor operation. A key characteristic of those sensors is that
the circuit they are in must be excited with a single, a pair, or two pairs
of signals. The external circuit can be excited either by a voltage supply
or by AD4170-4 excitation signals. The sensor can then be read through a
different pair of lines that are connected to the AD4170-4 ADC.

Extend the ad4170-4 driver to handle external circuit sensors.

Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
Link: https://patch.msgid.link/52686943040ecad34cc89833d4d5d37f1a51f412.1751895245.git.marcelo.schmitt@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2025-07-14 19:20:53 +01:00

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// SPDX-License-Identifier: GPL-2.0+
/*
* Analog Devices AD4170-4 ADC driver
*
* Copyright (C) 2025 Analog Devices, Inc.
* Author: Ana-Maria Cusco <ana-maria.cusco@analog.com>
* Author: Marcelo Schmitt <marcelo.schmitt@analog.com>
*/
#include <linux/array_size.h>
#include <linux/bitfield.h>
#include <linux/bitmap.h>
#include <linux/bitops.h>
#include <linux/bits.h>
#include <linux/cleanup.h>
#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/gpio/driver.h>
#include <linux/iio/buffer.h>
#include <linux/iio/iio.h>
#include <linux/iio/trigger.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/math64.h>
#include <linux/minmax.h>
#include <linux/module.h>
#include <linux/property.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>
#include <linux/spi/spi.h>
#include <linux/time.h>
#include <linux/types.h>
#include <linux/unaligned.h>
#include <linux/units.h>
#include <linux/util_macros.h>
/*
* AD4170 registers
* Multibyte register addresses point to the most significant byte which is the
* address to use to get the most significant byte first (address accessed is
* decremented by one for each data byte)
*
* Each register address define follows the AD4170_<REG_NAME>_REG format.
* Each mask follows the AD4170_<REG_NAME>_<FIELD_NAME> format.
* E.g. AD4170_PIN_MUXING_DIG_AUX1_CTRL_MSK is for accessing DIG_AUX1_CTRL field
* of PIN_MUXING_REG.
* Each constant follows the AD4170_<REG_NAME>_<FIELD_NAME>_<FUNCTION> format.
* E.g. AD4170_PIN_MUXING_DIG_AUX1_DISABLED is the value written to
* DIG_AUX1_CTRL field of PIN_MUXING register to disable DIG_AUX1 pin.
* Some register names and register field names are shortened versions of
* their datasheet counterpart names to provide better code readability.
*/
#define AD4170_CONFIG_A_REG 0x00
#define AD4170_DATA_24B_REG 0x1E
#define AD4170_PIN_MUXING_REG 0x69
#define AD4170_CLOCK_CTRL_REG 0x6B
#define AD4170_ADC_CTRL_REG 0x71
#define AD4170_CHAN_EN_REG 0x79
#define AD4170_CHAN_SETUP_REG(x) (0x81 + 4 * (x))
#define AD4170_CHAN_MAP_REG(x) (0x83 + 4 * (x))
#define AD4170_MISC_REG(x) (0xC1 + 14 * (x))
#define AD4170_AFE_REG(x) (0xC3 + 14 * (x))
#define AD4170_FILTER_REG(x) (0xC5 + 14 * (x))
#define AD4170_FILTER_FS_REG(x) (0xC7 + 14 * (x))
#define AD4170_OFFSET_REG(x) (0xCA + 14 * (x))
#define AD4170_GAIN_REG(x) (0xCD + 14 * (x))
#define AD4170_V_BIAS_REG 0x135
#define AD4170_CURRENT_SRC_REG(x) (0x139 + 2 * (x))
#define AD4170_GPIO_MODE_REG 0x191
#define AD4170_GPIO_OUTPUT_REG 0x193
#define AD4170_GPIO_INPUT_REG 0x195
#define AD4170_ADC_CTRL_CONT_READ_EXIT_REG 0x200 /* virtual reg */
#define AD4170_REG_READ_MASK BIT(14)
/* AD4170_CONFIG_A_REG - INTERFACE_CONFIG_A REGISTER */
#define AD4170_SW_RESET_MSK (BIT(7) | BIT(0))
/* AD4170_PIN_MUXING_REG */
#define AD4170_PIN_MUXING_DIG_AUX1_CTRL_MSK GENMASK(5, 4)
/* AD4170_CLOCK_CTRL_REG */
#define AD4170_CLOCK_CTRL_CLOCKSEL_MSK GENMASK(1, 0)
/* AD4170_ADC_CTRL_REG */
#define AD4170_ADC_CTRL_MULTI_DATA_REG_SEL_MSK BIT(7)
#define AD4170_ADC_CTRL_CONT_READ_MSK GENMASK(5, 4)
#define AD4170_ADC_CTRL_MODE_MSK GENMASK(3, 0)
/* AD4170_CHAN_EN_REG */
#define AD4170_CHAN_EN(ch) BIT(ch)
/* AD4170_CHAN_SETUP_REG */
#define AD4170_CHAN_SETUP_SETUP_MSK GENMASK(2, 0)
/* AD4170_CHAN_MAP_REG */
#define AD4170_CHAN_MAP_AINP_MSK GENMASK(12, 8)
#define AD4170_CHAN_MAP_AINM_MSK GENMASK(4, 0)
/* AD4170_MISC_REG */
#define AD4170_MISC_CHOP_IEXC_MSK GENMASK(15, 14)
#define AD4170_MISC_CHOP_ADC_MSK GENMASK(9, 8)
/* AD4170_AFE_REG */
#define AD4170_AFE_REF_BUF_M_MSK GENMASK(11, 10)
#define AD4170_AFE_REF_BUF_P_MSK GENMASK(9, 8)
#define AD4170_AFE_REF_SELECT_MSK GENMASK(6, 5)
#define AD4170_AFE_BIPOLAR_MSK BIT(4)
#define AD4170_AFE_PGA_GAIN_MSK GENMASK(3, 0)
/* AD4170_FILTER_REG */
#define AD4170_FILTER_FILTER_TYPE_MSK GENMASK(3, 0)
/* AD4170_CURRENT_SRC_REG */
#define AD4170_CURRENT_SRC_I_OUT_PIN_MSK GENMASK(12, 8)
#define AD4170_CURRENT_SRC_I_OUT_VAL_MSK GENMASK(2, 0)
/* AD4170_GPIO_MODE_REG */
#define AD4170_GPIO_MODE_GPIO0_MSK GENMASK(1, 0)
#define AD4170_GPIO_MODE_GPIO1_MSK GENMASK(3, 2)
#define AD4170_GPIO_MODE_GPIO2_MSK GENMASK(5, 4)
#define AD4170_GPIO_MODE_GPIO3_MSK GENMASK(7, 6)
/* AD4170_GPIO_OUTPUT_REG */
#define AD4170_GPIO_OUTPUT_GPIO_MSK(x) BIT(x)
/* AD4170 register constants */
/* AD4170_CLOCK_CTRL_REG constants */
#define AD4170_CLOCK_CTRL_CLOCKSEL_INT 0x0
#define AD4170_CLOCK_CTRL_CLOCKSEL_INT_OUT 0x1
#define AD4170_CLOCK_CTRL_CLOCKSEL_EXT 0x2
#define AD4170_CLOCK_CTRL_CLOCKSEL_EXT_XTAL 0x3
/* AD4170_CHAN_MAP_REG constants */
#define AD4170_CHAN_MAP_AIN(x) (x)
#define AD4170_CHAN_MAP_TEMP_SENSOR 17
#define AD4170_CHAN_MAP_AVDD_AVSS_P 18
#define AD4170_CHAN_MAP_AVDD_AVSS_N 18
#define AD4170_CHAN_MAP_IOVDD_DGND_P 19
#define AD4170_CHAN_MAP_IOVDD_DGND_N 19
#define AD4170_CHAN_MAP_AVSS 23
#define AD4170_CHAN_MAP_DGND 24
#define AD4170_CHAN_MAP_REFIN1_P 25
#define AD4170_CHAN_MAP_REFIN1_N 26
#define AD4170_CHAN_MAP_REFIN2_P 27
#define AD4170_CHAN_MAP_REFIN2_N 28
#define AD4170_CHAN_MAP_REFOUT 29
/* AD4170_MISC_REG constants */
#define AD4170_MISC_CHOP_IEXC_PAIR1 0x1
#define AD4170_MISC_CHOP_IEXC_PAIR2 0x2
#define AD4170_MISC_CHOP_IEXC_BOTH 0x3
/* AD4170_PIN_MUXING_REG constants */
#define AD4170_PIN_MUXING_DIG_AUX1_DISABLED 0x0
#define AD4170_PIN_MUXING_DIG_AUX1_RDY 0x1
/* AD4170_ADC_CTRL_REG constants */
#define AD4170_ADC_CTRL_MODE_CONT 0x0
#define AD4170_ADC_CTRL_MODE_SINGLE 0x4
#define AD4170_ADC_CTRL_MODE_IDLE 0x7
#define AD4170_ADC_CTRL_CONT_READ_DISABLE 0x0
#define AD4170_ADC_CTRL_CONT_READ_ENABLE 0x1
/* AD4170_FILTER_REG constants */
#define AD4170_FILTER_FILTER_TYPE_SINC5_AVG 0x0
#define AD4170_FILTER_FILTER_TYPE_SINC5 0x4
#define AD4170_FILTER_FILTER_TYPE_SINC3 0x6
/* AD4170_CURRENT_SRC_REG constants */
#define AD4170_CURRENT_SRC_I_OUT_PIN_AIN(x) (x)
#define AD4170_CURRENT_SRC_I_OUT_PIN_GPIO(x) ((x) + 17)
/* AD4170_GPIO_MODE_REG constants */
#define AD4170_GPIO_MODE_GPIO_INPUT 1
#define AD4170_GPIO_MODE_GPIO_OUTPUT 2
/* Device properties and auxiliary constants */
#define AD4170_NUM_ANALOG_PINS 9
#define AD4170_NUM_GPIO_PINS 4
#define AD4170_MAX_ADC_CHANNELS 16
#define AD4170_MAX_IIO_CHANNELS (AD4170_MAX_ADC_CHANNELS + 1)
#define AD4170_MAX_ANALOG_PINS 8
#define AD4170_MAX_SETUPS 8
#define AD4170_INVALID_SETUP 9
#define AD4170_SPI_INST_PHASE_LEN 2
#define AD4170_SPI_MAX_XFER_LEN 6
#define AD4170_NUM_CURRENT_SRC 4
#define AD4170_DEFAULT_SAMP_RATE (125 * HZ_PER_KHZ)
#define AD4170_INT_REF_2_5V 2500000
/* Internal and external clock properties */
#define AD4170_INT_CLOCK_16MHZ (16 * HZ_PER_MHZ)
#define AD4170_EXT_CLOCK_MHZ_MIN (1 * HZ_PER_MHZ)
#define AD4170_EXT_CLOCK_MHZ_MAX (17 * HZ_PER_MHZ)
#define AD4170_NUM_PGA_OPTIONS 10
/* Digital filter properties */
#define AD4170_SINC3_MIN_FS 4
#define AD4170_SINC3_MAX_FS 65532
#define AD4170_SINC5_MIN_FS 1
#define AD4170_SINC5_MAX_FS 256
#define AD4170_GAIN_REG_DEFAULT 0x555555
#define AD4170_ADC_CTRL_CONT_READ_EXIT 0xA5
/* Analog pin functions */
#define AD4170_PIN_UNASSIGNED 0x00
#define AD4170_PIN_ANALOG_IN 0x01
#define AD4170_PIN_CURRENT_OUT 0x02
#define AD4170_PIN_VBIAS 0x04
/* GPIO pin functions */
#define AD4170_GPIO_UNASSIGNED 0x00
#define AD4170_GPIO_AC_EXCITATION 0x02
#define AD4170_GPIO_OUTPUT 0x04
/* Current source */
#define AD4170_CURRENT_SRC_DISABLED 0xFF
static const unsigned int ad4170_reg_size[] = {
[AD4170_CONFIG_A_REG] = 1,
[AD4170_DATA_24B_REG] = 3,
[AD4170_PIN_MUXING_REG] = 2,
[AD4170_CLOCK_CTRL_REG] = 2,
[AD4170_ADC_CTRL_REG] = 2,
[AD4170_CHAN_EN_REG] = 2,
/*
* CHANNEL_SETUP and CHANNEL_MAP register are all 2 byte size each and
* their addresses are interleaved such that we have CHANNEL_SETUP0
* address followed by CHANNEL_MAP0 address, followed by CHANNEL_SETUP1,
* and so on until CHANNEL_MAP15.
* Thus, initialize the register size for them only once.
*/
[AD4170_CHAN_SETUP_REG(0) ... AD4170_CHAN_MAP_REG(AD4170_MAX_ADC_CHANNELS - 1)] = 2,
/*
* MISC, AFE, FILTER, FILTER_FS, OFFSET, and GAIN register addresses are
* also interleaved but MISC, AFE, FILTER, FILTER_FS, OFFSET are 16-bit
* while OFFSET, GAIN are 24-bit registers so we can't init them all to
* the same size.
*/
[AD4170_MISC_REG(0) ... AD4170_FILTER_FS_REG(0)] = 2,
[AD4170_MISC_REG(1) ... AD4170_FILTER_FS_REG(1)] = 2,
[AD4170_MISC_REG(2) ... AD4170_FILTER_FS_REG(2)] = 2,
[AD4170_MISC_REG(3) ... AD4170_FILTER_FS_REG(3)] = 2,
[AD4170_MISC_REG(4) ... AD4170_FILTER_FS_REG(4)] = 2,
[AD4170_MISC_REG(5) ... AD4170_FILTER_FS_REG(5)] = 2,
[AD4170_MISC_REG(6) ... AD4170_FILTER_FS_REG(6)] = 2,
[AD4170_MISC_REG(7) ... AD4170_FILTER_FS_REG(7)] = 2,
[AD4170_OFFSET_REG(0) ... AD4170_GAIN_REG(0)] = 3,
[AD4170_OFFSET_REG(1) ... AD4170_GAIN_REG(1)] = 3,
[AD4170_OFFSET_REG(2) ... AD4170_GAIN_REG(2)] = 3,
[AD4170_OFFSET_REG(3) ... AD4170_GAIN_REG(3)] = 3,
[AD4170_OFFSET_REG(4) ... AD4170_GAIN_REG(4)] = 3,
[AD4170_OFFSET_REG(5) ... AD4170_GAIN_REG(5)] = 3,
[AD4170_OFFSET_REG(6) ... AD4170_GAIN_REG(6)] = 3,
[AD4170_OFFSET_REG(7) ... AD4170_GAIN_REG(7)] = 3,
[AD4170_V_BIAS_REG] = 2,
[AD4170_CURRENT_SRC_REG(0) ... AD4170_CURRENT_SRC_REG(3)] = 2,
[AD4170_GPIO_MODE_REG] = 2,
[AD4170_GPIO_OUTPUT_REG] = 2,
[AD4170_GPIO_INPUT_REG] = 2,
[AD4170_ADC_CTRL_CONT_READ_EXIT_REG] = 0,
};
enum ad4170_ref_buf {
AD4170_REF_BUF_PRE, /* Pre-charge referrence buffer */
AD4170_REF_BUF_FULL, /* Full referrence buffering */
AD4170_REF_BUF_BYPASS, /* Bypass referrence buffering */
};
/* maps adi,positive/negative-reference-buffer property values to enum */
static const char * const ad4170_ref_buf_str[] = {
[AD4170_REF_BUF_PRE] = "precharge",
[AD4170_REF_BUF_FULL] = "full",
[AD4170_REF_BUF_BYPASS] = "disabled",
};
enum ad4170_ref_select {
AD4170_REF_REFIN1,
AD4170_REF_REFIN2,
AD4170_REF_REFOUT,
AD4170_REF_AVDD,
};
enum ad4170_filter_type {
AD4170_SINC5_AVG,
AD4170_SINC5,
AD4170_SINC3,
};
enum ad4170_regulator {
AD4170_AVDD_SUP,
AD4170_AVSS_SUP,
AD4170_IOVDD_SUP,
AD4170_REFIN1P_SUP,
AD4170_REFIN1N_SUP,
AD4170_REFIN2P_SUP,
AD4170_REFIN2N_SUP,
AD4170_MAX_SUP,
};
static const char *const ad4170_clk_sel[] = {
"ext-clk", "xtal",
};
enum ad4170_int_pin_sel {
AD4170_INT_PIN_SDO,
AD4170_INT_PIN_DIG_AUX1,
};
static const char * const ad4170_int_pin_names[] = {
[AD4170_INT_PIN_SDO] = "sdo",
[AD4170_INT_PIN_DIG_AUX1] = "dig_aux1",
};
static const unsigned int ad4170_sinc3_filt_fs_tbl[] = {
4, 8, 12, 16, 20, 40, 48, 80, /* 0 - 7 */
100, 256, 500, 1000, 5000, 8332, 10000, 25000, /* 8 - 15 */
50000, 65532, /* 16 - 17 */
};
#define AD4170_MAX_FS_TBL_SIZE ARRAY_SIZE(ad4170_sinc3_filt_fs_tbl)
static const unsigned int ad4170_sinc5_filt_fs_tbl[] = {
1, 2, 4, 8, 12, 16, 20, 40, 48, 80, 100, 256,
};
static const unsigned int ad4170_iout_pin_tbl[] = {
AD4170_CURRENT_SRC_I_OUT_PIN_AIN(0),
AD4170_CURRENT_SRC_I_OUT_PIN_AIN(1),
AD4170_CURRENT_SRC_I_OUT_PIN_AIN(2),
AD4170_CURRENT_SRC_I_OUT_PIN_AIN(3),
AD4170_CURRENT_SRC_I_OUT_PIN_AIN(4),
AD4170_CURRENT_SRC_I_OUT_PIN_AIN(5),
AD4170_CURRENT_SRC_I_OUT_PIN_AIN(6),
AD4170_CURRENT_SRC_I_OUT_PIN_AIN(7),
AD4170_CURRENT_SRC_I_OUT_PIN_AIN(8),
AD4170_CURRENT_SRC_I_OUT_PIN_GPIO(0),
AD4170_CURRENT_SRC_I_OUT_PIN_GPIO(1),
AD4170_CURRENT_SRC_I_OUT_PIN_GPIO(2),
AD4170_CURRENT_SRC_I_OUT_PIN_GPIO(3),
};
static const unsigned int ad4170_iout_current_ua_tbl[] = {
0, 10, 50, 100, 250, 500, 1000, 1500,
};
enum ad4170_sensor_enum {
AD4170_ADC_SENSOR = 0,
AD4170_WEIGH_SCALE_SENSOR = 1,
AD4170_RTD_SENSOR = 2,
AD4170_THERMOCOUPLE_SENSOR = 3,
};
/* maps adi,sensor-type property value to enum */
static const char * const ad4170_sensor_type[] = {
[AD4170_ADC_SENSOR] = "adc",
[AD4170_WEIGH_SCALE_SENSOR] = "weighscale",
[AD4170_RTD_SENSOR] = "rtd",
[AD4170_THERMOCOUPLE_SENSOR] = "thermocouple",
};
struct ad4170_chip_info {
const char *name;
};
static const struct ad4170_chip_info ad4170_chip_info = {
.name = "ad4170-4",
};
static const struct ad4170_chip_info ad4190_chip_info = {
.name = "ad4190-4",
};
static const struct ad4170_chip_info ad4195_chip_info = {
.name = "ad4195-4",
};
/*
* There are 8 of each MISC, AFE, FILTER, FILTER_FS, OFFSET, and GAIN
* configuration registers. That is, there are 8 miscellaneous registers, MISC0
* to MISC7. Each MISC register is associated with a setup; MISCN is associated
* with setup number N. The other 5 above mentioned types of registers have
* analogous structure. A setup is a set of those registers. For example,
* setup 1 comprises of MISC1, AFE1, FILTER1, FILTER_FS1, OFFSET1, and GAIN1
* registers. Also, there are 16 CHANNEL_SETUP registers (CHANNEL_SETUP0 to
* CHANNEL_SETUP15). Each channel setup is associated with one of the 8 possible
* setups. Thus, AD4170 can support up to 16 channels but, since there are only
* 8 available setups, channels must share settings if more than 8 channels are
* configured.
*
* If this struct is modified, ad4170_setup_eq() will probably need to be
* updated too.
*/
struct ad4170_setup {
u16 misc;
u16 afe;
u16 filter;
u16 filter_fs;
u32 offset; /* For calibration purposes */
u32 gain; /* For calibration purposes */
};
struct ad4170_setup_info {
struct ad4170_setup setup;
unsigned int enabled_channels;
unsigned int channels;
};
struct ad4170_chan_info {
unsigned int input_range_uv;
unsigned int setup_num; /* Index to access state setup_infos array */
struct ad4170_setup setup; /* cached setup */
int offset_tbl[10];
u32 scale_tbl[10][2];
bool initialized;
bool enabled;
};
static const char * const ad4170_filt_names[] = {
[AD4170_SINC5_AVG] = "sinc5+avg",
[AD4170_SINC5] = "sinc5",
[AD4170_SINC3] = "sinc3",
};
struct ad4170_state {
struct mutex lock; /* Protect read-modify-write and multi write sequences */
int vrefs_uv[AD4170_MAX_SUP];
u32 mclk_hz;
struct ad4170_setup_info setup_infos[AD4170_MAX_SETUPS];
struct ad4170_chan_info chan_infos[AD4170_MAX_ADC_CHANNELS];
struct completion completion;
struct iio_chan_spec chans[AD4170_MAX_IIO_CHANNELS];
struct spi_device *spi;
struct regmap *regmap;
int sps_tbl[ARRAY_SIZE(ad4170_filt_names)][AD4170_MAX_FS_TBL_SIZE][2];
__be32 bounce_buffer[AD4170_MAX_ADC_CHANNELS];
struct spi_message msg;
struct spi_transfer xfer;
struct iio_trigger *trig;
struct clk_hw int_clk_hw;
unsigned int clock_ctrl;
unsigned int pins_fn[AD4170_NUM_ANALOG_PINS];
int gpio_fn[AD4170_NUM_GPIO_PINS];
unsigned int cur_src_pins[AD4170_NUM_CURRENT_SRC];
struct gpio_chip gpiochip;
/*
* DMA (thus cache coherency maintenance) requires the transfer buffers
* to live in their own cache lines.
*/
u8 rx_buf[4] __aligned(IIO_DMA_MINALIGN);
};
static void ad4170_fill_sps_tbl(struct ad4170_state *st)
{
unsigned int tmp0, tmp1, i;
/*
* The ODR can be calculated the same way for sinc5+avg, sinc5, and
* sinc3 filter types with the exception that sinc5 filter has a
* narrowed range of allowed FILTER_FS values.
*/
for (i = 0; i < ARRAY_SIZE(ad4170_sinc3_filt_fs_tbl); i++) {
tmp0 = div_u64_rem(st->mclk_hz, 32 * ad4170_sinc3_filt_fs_tbl[i],
&tmp1);
tmp1 = mult_frac(tmp1, MICRO, 32 * ad4170_sinc3_filt_fs_tbl[i]);
/* Fill sinc5+avg filter SPS table */
st->sps_tbl[AD4170_SINC5_AVG][i][0] = tmp0; /* Integer part */
st->sps_tbl[AD4170_SINC5_AVG][i][1] = tmp1; /* Fractional part */
/* Fill sinc3 filter SPS table */
st->sps_tbl[AD4170_SINC3][i][0] = tmp0; /* Integer part */
st->sps_tbl[AD4170_SINC3][i][1] = tmp1; /* Fractional part */
}
/* Sinc5 filter ODR doesn't use all FILTER_FS bits */
for (i = 0; i < ARRAY_SIZE(ad4170_sinc5_filt_fs_tbl); i++) {
tmp0 = div_u64_rem(st->mclk_hz, 32 * ad4170_sinc5_filt_fs_tbl[i],
&tmp1);
tmp1 = mult_frac(tmp1, MICRO, 32 * ad4170_sinc5_filt_fs_tbl[i]);
/* Fill sinc5 filter SPS table */
st->sps_tbl[AD4170_SINC5][i][0] = tmp0; /* Integer part */
st->sps_tbl[AD4170_SINC5][i][1] = tmp1; /* Fractional part */
}
}
static int ad4170_debugfs_reg_access(struct iio_dev *indio_dev,
unsigned int reg, unsigned int writeval,
unsigned int *readval)
{
struct ad4170_state *st = iio_priv(indio_dev);
if (readval)
return regmap_read(st->regmap, reg, readval);
return regmap_write(st->regmap, reg, writeval);
}
static int ad4170_get_reg_size(struct ad4170_state *st, unsigned int reg,
unsigned int *size)
{
if (reg >= ARRAY_SIZE(ad4170_reg_size))
return -EINVAL;
*size = ad4170_reg_size[reg];
return 0;
}
static int ad4170_reg_write(void *context, unsigned int reg, unsigned int val)
{
struct ad4170_state *st = context;
u8 tx_buf[AD4170_SPI_MAX_XFER_LEN];
unsigned int size;
int ret;
ret = ad4170_get_reg_size(st, reg, &size);
if (ret)
return ret;
put_unaligned_be16(reg, tx_buf);
switch (size) {
case 3:
put_unaligned_be24(val, &tx_buf[AD4170_SPI_INST_PHASE_LEN]);
break;
case 2:
put_unaligned_be16(val, &tx_buf[AD4170_SPI_INST_PHASE_LEN]);
break;
case 1:
tx_buf[AD4170_SPI_INST_PHASE_LEN] = val;
break;
case 0:
/* Write continuous read exit code */
tx_buf[0] = AD4170_ADC_CTRL_CONT_READ_EXIT;
return spi_write_then_read(st->spi, tx_buf, 1, NULL, 0);
default:
return -EINVAL;
}
return spi_write_then_read(st->spi, tx_buf,
AD4170_SPI_INST_PHASE_LEN + size, NULL, 0);
}
static int ad4170_reg_read(void *context, unsigned int reg, unsigned int *val)
{
struct ad4170_state *st = context;
u8 tx_buf[AD4170_SPI_INST_PHASE_LEN];
unsigned int size;
int ret;
put_unaligned_be16(AD4170_REG_READ_MASK | reg, tx_buf);
ret = ad4170_get_reg_size(st, reg, &size);
if (ret)
return ret;
ret = spi_write_then_read(st->spi, tx_buf, ARRAY_SIZE(tx_buf),
st->rx_buf, size);
if (ret)
return ret;
switch (size) {
case 3:
*val = get_unaligned_be24(st->rx_buf);
return 0;
case 2:
*val = get_unaligned_be16(st->rx_buf);
return 0;
case 1:
*val = st->rx_buf[0];
return 0;
default:
return -EINVAL;
}
}
static const struct regmap_config ad4170_regmap_config = {
.reg_read = ad4170_reg_read,
.reg_write = ad4170_reg_write,
};
static bool ad4170_setup_eq(struct ad4170_setup *a, struct ad4170_setup *b)
{
if (a->misc != b->misc ||
a->afe != b->afe ||
a->filter != b->filter ||
a->filter_fs != b->filter_fs ||
a->offset != b->offset ||
a->gain != b->gain)
return false;
return true;
}
static int ad4170_find_setup(struct ad4170_state *st,
struct ad4170_setup *target_setup,
unsigned int *setup_num, bool *overwrite)
{
unsigned int i;
*setup_num = AD4170_INVALID_SETUP;
*overwrite = false;
for (i = 0; i < AD4170_MAX_SETUPS; i++) {
struct ad4170_setup_info *setup_info = &st->setup_infos[i];
/* Immediately accept a matching setup. */
if (ad4170_setup_eq(target_setup, &setup_info->setup)) {
*setup_num = i;
return 0;
}
/* Ignore all setups which are used by enabled channels. */
if (setup_info->enabled_channels)
continue;
/* Find the least used slot. */
if (*setup_num == AD4170_INVALID_SETUP ||
setup_info->channels < st->setup_infos[*setup_num].channels)
*setup_num = i;
}
if (*setup_num == AD4170_INVALID_SETUP)
return -EINVAL;
*overwrite = true;
return 0;
}
static void ad4170_unlink_channel(struct ad4170_state *st, unsigned int channel)
{
struct ad4170_chan_info *chan_info = &st->chan_infos[channel];
struct ad4170_setup_info *setup_info = &st->setup_infos[chan_info->setup_num];
chan_info->setup_num = AD4170_INVALID_SETUP;
setup_info->channels--;
}
static int ad4170_unlink_setup(struct ad4170_state *st, unsigned int setup_num)
{
unsigned int i;
for (i = 0; i < AD4170_MAX_ADC_CHANNELS; i++) {
struct ad4170_chan_info *chan_info = &st->chan_infos[i];
if (!chan_info->initialized || chan_info->setup_num != setup_num)
continue;
ad4170_unlink_channel(st, i);
}
return 0;
}
static int ad4170_link_channel_setup(struct ad4170_state *st,
unsigned int chan_addr,
unsigned int setup_num)
{
struct ad4170_setup_info *setup_info = &st->setup_infos[setup_num];
struct ad4170_chan_info *chan_info = &st->chan_infos[chan_addr];
int ret;
ret = regmap_update_bits(st->regmap, AD4170_CHAN_SETUP_REG(chan_addr),
AD4170_CHAN_SETUP_SETUP_MSK,
FIELD_PREP(AD4170_CHAN_SETUP_SETUP_MSK, setup_num));
if (ret)
return ret;
chan_info->setup_num = setup_num;
setup_info->channels++;
return 0;
}
static int ad4170_write_setup(struct ad4170_state *st, unsigned int setup_num,
struct ad4170_setup *setup)
{
int ret;
/*
* It is recommended to place the ADC in standby mode or idle mode to
* write to OFFSET and GAIN registers.
*/
ret = regmap_update_bits(st->regmap, AD4170_ADC_CTRL_REG,
AD4170_ADC_CTRL_MODE_MSK,
FIELD_PREP(AD4170_ADC_CTRL_MODE_MSK,
AD4170_ADC_CTRL_MODE_IDLE));
if (ret)
return ret;
ret = regmap_write(st->regmap, AD4170_MISC_REG(setup_num), setup->misc);
if (ret)
return ret;
ret = regmap_write(st->regmap, AD4170_AFE_REG(setup_num), setup->afe);
if (ret)
return ret;
ret = regmap_write(st->regmap, AD4170_FILTER_REG(setup_num),
setup->filter);
if (ret)
return ret;
ret = regmap_write(st->regmap, AD4170_FILTER_FS_REG(setup_num),
setup->filter_fs);
if (ret)
return ret;
ret = regmap_write(st->regmap, AD4170_OFFSET_REG(setup_num),
setup->offset);
if (ret)
return ret;
ret = regmap_write(st->regmap, AD4170_GAIN_REG(setup_num), setup->gain);
if (ret)
return ret;
memcpy(&st->setup_infos[setup_num].setup, setup, sizeof(*setup));
return 0;
}
static int ad4170_write_channel_setup(struct ad4170_state *st,
unsigned int chan_addr, bool on_enable)
{
struct ad4170_chan_info *chan_info = &st->chan_infos[chan_addr];
bool overwrite;
int setup_num;
int ret;
/*
* Similar to AD4130 driver, the following cases need to be handled.
*
* 1. Enabled and linked channel with setup changes:
* - Find a setup. If not possible, return error.
* - Unlink channel from current setup.
* - If the setup found has only disabled channels linked to it,
* unlink all channels, and write the new setup to it.
* - Link channel to new setup.
*
* 2. Soon to be enabled and unlinked channel:
* - Find a setup. If not possible, return error.
* - If the setup found has only disabled channels linked to it,
* unlink all channels, and write the new setup to it.
* - Link channel to the setup.
*
* 3. Disabled and linked channel with setup changes:
* - Unlink channel from current setup.
*
* 4. Soon to be enabled and linked channel:
* 5. Disabled and unlinked channel with setup changes:
* - Do nothing.
*/
/* Cases 3, 4, and 5 */
if (chan_info->setup_num != AD4170_INVALID_SETUP) {
/* Case 4 */
if (on_enable)
return 0;
/* Case 3 */
if (!chan_info->enabled) {
ad4170_unlink_channel(st, chan_addr);
return 0;
}
} else if (!on_enable && !chan_info->enabled) {
/* Case 5 */
return 0;
}
/* Cases 1 & 2 */
ret = ad4170_find_setup(st, &chan_info->setup, &setup_num, &overwrite);
if (ret)
return ret;
if (chan_info->setup_num != AD4170_INVALID_SETUP)
/* Case 1 */
ad4170_unlink_channel(st, chan_addr);
if (overwrite) {
ret = ad4170_unlink_setup(st, setup_num);
if (ret)
return ret;
ret = ad4170_write_setup(st, setup_num, &chan_info->setup);
if (ret)
return ret;
}
return ad4170_link_channel_setup(st, chan_addr, setup_num);
}
static int ad4170_set_channel_enable(struct ad4170_state *st,
unsigned int chan_addr, bool status)
{
struct ad4170_chan_info *chan_info = &st->chan_infos[chan_addr];
struct ad4170_setup_info *setup_info;
int ret;
if (chan_info->enabled == status)
return 0;
if (status) {
ret = ad4170_write_channel_setup(st, chan_addr, true);
if (ret)
return ret;
}
setup_info = &st->setup_infos[chan_info->setup_num];
ret = regmap_update_bits(st->regmap, AD4170_CHAN_EN_REG,
AD4170_CHAN_EN(chan_addr),
status ? AD4170_CHAN_EN(chan_addr) : 0);
if (ret)
return ret;
setup_info->enabled_channels += status ? 1 : -1;
chan_info->enabled = status;
return 0;
}
static int __ad4170_get_filter_type(unsigned int filter)
{
u16 f_conf = FIELD_GET(AD4170_FILTER_FILTER_TYPE_MSK, filter);
switch (f_conf) {
case AD4170_FILTER_FILTER_TYPE_SINC5_AVG:
return AD4170_SINC5_AVG;
case AD4170_FILTER_FILTER_TYPE_SINC5:
return AD4170_SINC5;
case AD4170_FILTER_FILTER_TYPE_SINC3:
return AD4170_SINC3;
default:
return -EINVAL;
}
}
static int ad4170_set_filter_type(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
unsigned int val)
{
struct ad4170_state *st = iio_priv(indio_dev);
struct ad4170_chan_info *chan_info = &st->chan_infos[chan->address];
struct ad4170_setup *setup = &chan_info->setup;
unsigned int filter_type_conf;
int ret;
switch (val) {
case AD4170_SINC5_AVG:
filter_type_conf = AD4170_FILTER_FILTER_TYPE_SINC5_AVG;
break;
case AD4170_SINC5:
filter_type_conf = AD4170_FILTER_FILTER_TYPE_SINC5;
break;
case AD4170_SINC3:
filter_type_conf = AD4170_FILTER_FILTER_TYPE_SINC3;
break;
default:
return -EINVAL;
}
/*
* The filters provide the same ODR for a given filter_fs value but
* there are different minimum and maximum filter_fs limits for each
* filter. The filter_fs value will be adjusted if the current filter_fs
* is out of the limits of the just requested filter. Since the
* filter_fs value affects the ODR (sampling_frequency), changing the
* filter may lead to a change in the sampling frequency.
*/
scoped_guard(mutex, &st->lock) {
if (!iio_device_claim_direct(indio_dev))
return -EBUSY;
if (val == AD4170_SINC5_AVG || val == AD4170_SINC3)
setup->filter_fs = clamp(val, AD4170_SINC3_MIN_FS,
AD4170_SINC3_MAX_FS);
else
setup->filter_fs = clamp(val, AD4170_SINC5_MIN_FS,
AD4170_SINC5_MAX_FS);
setup->filter &= ~AD4170_FILTER_FILTER_TYPE_MSK;
setup->filter |= FIELD_PREP(AD4170_FILTER_FILTER_TYPE_MSK,
filter_type_conf);
ret = ad4170_write_channel_setup(st, chan->address, false);
iio_device_release_direct(indio_dev);
}
return ret;
}
static int ad4170_get_filter_type(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan)
{
struct ad4170_state *st = iio_priv(indio_dev);
struct ad4170_chan_info *chan_info = &st->chan_infos[chan->address];
struct ad4170_setup *setup = &chan_info->setup;
return __ad4170_get_filter_type(setup->filter);
}
static const struct iio_enum ad4170_filter_type_enum = {
.items = ad4170_filt_names,
.num_items = ARRAY_SIZE(ad4170_filt_names),
.get = ad4170_get_filter_type,
.set = ad4170_set_filter_type,
};
static const struct iio_chan_spec_ext_info ad4170_filter_type_ext_info[] = {
IIO_ENUM("filter_type", IIO_SEPARATE, &ad4170_filter_type_enum),
IIO_ENUM_AVAILABLE("filter_type", IIO_SHARED_BY_TYPE,
&ad4170_filter_type_enum),
{ }
};
static const struct iio_chan_spec ad4170_channel_template = {
.type = IIO_VOLTAGE,
.indexed = 1,
.differential = 1,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_SCALE) |
BIT(IIO_CHAN_INFO_CALIBBIAS) |
BIT(IIO_CHAN_INFO_CALIBSCALE) |
BIT(IIO_CHAN_INFO_SAMP_FREQ) |
BIT(IIO_CHAN_INFO_OFFSET),
.info_mask_separate_available = BIT(IIO_CHAN_INFO_SCALE) |
BIT(IIO_CHAN_INFO_SAMP_FREQ),
.ext_info = ad4170_filter_type_ext_info,
.scan_type = {
.realbits = 24,
.storagebits = 32,
.shift = 8,
.endianness = IIO_BE,
},
};
static const struct iio_chan_spec ad4170_temp_channel_template = {
.type = IIO_TEMP,
.indexed = 0,
.channel = 17,
.channel2 = 17,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_SCALE) |
BIT(IIO_CHAN_INFO_OFFSET) |
BIT(IIO_CHAN_INFO_CALIBSCALE) |
BIT(IIO_CHAN_INFO_CALIBBIAS) |
BIT(IIO_CHAN_INFO_SAMP_FREQ),
.info_mask_separate_available = BIT(IIO_CHAN_INFO_SAMP_FREQ),
.scan_type = {
.sign = 's',
.realbits = 24,
.storagebits = 32,
.shift = 8,
.endianness = IIO_BE,
},
};
/*
* Receives the number of a multiplexed AD4170 input (ain_n), and stores the
* voltage (in µV) of the specified input into ain_voltage. If the input number
* is a ordinary analog input (AIN0 to AIN8), stores zero into ain_voltage.
* If a voltage regulator required by a special input is unavailable, return
* error code. Return 0 on success.
*/
static int ad4170_get_ain_voltage_uv(struct ad4170_state *st, int ain_n,
int *ain_voltage)
{
struct device *dev = &st->spi->dev;
int v_diff;
*ain_voltage = 0;
/*
* The voltage bias (vbias) sets the common-mode voltage of the channel
* to (AVDD + AVSS)/2. If provided, AVSS supply provides the magnitude
* (absolute value) of the negative voltage supplied to the AVSS pin.
* So, we do AVDD - AVSS to compute the DC voltage generated by the bias
* voltage generator.
*/
if (st->pins_fn[ain_n] & AD4170_PIN_VBIAS) {
int v_diff = st->vrefs_uv[AD4170_AVDD_SUP] - st->vrefs_uv[AD4170_AVSS_SUP];
*ain_voltage = v_diff / 2;
return 0;
}
if (ain_n <= AD4170_CHAN_MAP_TEMP_SENSOR)
return 0;
switch (ain_n) {
case AD4170_CHAN_MAP_AVDD_AVSS_N:
v_diff = st->vrefs_uv[AD4170_AVDD_SUP] - st->vrefs_uv[AD4170_AVSS_SUP];
*ain_voltage = v_diff / 5;
return 0;
case AD4170_CHAN_MAP_IOVDD_DGND_N:
*ain_voltage = st->vrefs_uv[AD4170_IOVDD_SUP] / 5;
return 0;
case AD4170_CHAN_MAP_AVSS:
*ain_voltage = st->vrefs_uv[AD4170_AVSS_SUP];
return 0;
case AD4170_CHAN_MAP_DGND:
*ain_voltage = 0;
return 0;
case AD4170_CHAN_MAP_REFIN1_P:
if (st->vrefs_uv[AD4170_REFIN1P_SUP] == -ENODEV)
return dev_err_probe(dev, -ENODEV,
"input set to REFIN+ but ref not provided\n");
*ain_voltage = st->vrefs_uv[AD4170_REFIN1P_SUP];
return 0;
case AD4170_CHAN_MAP_REFIN1_N:
if (st->vrefs_uv[AD4170_REFIN1N_SUP] == -ENODEV)
return dev_err_probe(dev, -ENODEV,
"input set to REFIN- but ref not provided\n");
*ain_voltage = st->vrefs_uv[AD4170_REFIN1N_SUP];
return 0;
case AD4170_CHAN_MAP_REFIN2_P:
if (st->vrefs_uv[AD4170_REFIN2P_SUP] == -ENODEV)
return dev_err_probe(dev, -ENODEV,
"input set to REFIN2+ but ref not provided\n");
*ain_voltage = st->vrefs_uv[AD4170_REFIN2P_SUP];
return 0;
case AD4170_CHAN_MAP_REFIN2_N:
if (st->vrefs_uv[AD4170_REFIN2N_SUP] == -ENODEV)
return dev_err_probe(dev, -ENODEV,
"input set to REFIN2- but ref not provided\n");
*ain_voltage = st->vrefs_uv[AD4170_REFIN2N_SUP];
return 0;
case AD4170_CHAN_MAP_REFOUT:
/* REFOUT is 2.5V relative to AVSS so take that into account */
*ain_voltage = st->vrefs_uv[AD4170_AVSS_SUP] + AD4170_INT_REF_2_5V;
return 0;
default:
return -EINVAL;
}
}
static int ad4170_validate_analog_input(struct ad4170_state *st, int pin)
{
if (pin <= AD4170_MAX_ANALOG_PINS) {
if (st->pins_fn[pin] & AD4170_PIN_CURRENT_OUT)
return dev_err_probe(&st->spi->dev, -EINVAL,
"Pin %d already used with fn %u.\n",
pin, st->pins_fn[pin]);
st->pins_fn[pin] |= AD4170_PIN_ANALOG_IN;
}
return 0;
}
static int ad4170_validate_channel_input(struct ad4170_state *st, int pin, bool com)
{
/* Check common-mode input pin is mapped to a special input. */
if (com && (pin < AD4170_CHAN_MAP_AVDD_AVSS_P || pin > AD4170_CHAN_MAP_REFOUT))
return dev_err_probe(&st->spi->dev, -EINVAL,
"Invalid common-mode input pin number. %d\n",
pin);
/* Check differential input pin is mapped to a analog input pin. */
if (!com && pin > AD4170_MAX_ANALOG_PINS)
return dev_err_probe(&st->spi->dev, -EINVAL,
"Invalid analog input pin number. %d\n",
pin);
return ad4170_validate_analog_input(st, pin);
}
/*
* Verifies whether the channel input configuration is valid by checking the
* input numbers.
* Returns 0 on valid channel input configuration. -EINVAL otherwise.
*/
static int ad4170_validate_channel(struct ad4170_state *st,
struct iio_chan_spec const *chan)
{
int ret;
ret = ad4170_validate_channel_input(st, chan->channel, false);
if (ret)
return ret;
return ad4170_validate_channel_input(st, chan->channel2,
!chan->differential);
}
/*
* Verifies whether the channel configuration is valid by checking the provided
* input type, polarity, and voltage references result in a sane input range.
* Returns negative error code on failure.
*/
static int ad4170_get_input_range(struct ad4170_state *st,
struct iio_chan_spec const *chan,
unsigned int ch_reg, unsigned int ref_sel)
{
bool bipolar = chan->scan_type.sign == 's';
struct device *dev = &st->spi->dev;
int refp, refn, ain_voltage, ret;
switch (ref_sel) {
case AD4170_REF_REFIN1:
if (st->vrefs_uv[AD4170_REFIN1P_SUP] == -ENODEV ||
st->vrefs_uv[AD4170_REFIN1N_SUP] == -ENODEV)
return dev_err_probe(dev, -ENODEV,
"REFIN± selected but not provided\n");
refp = st->vrefs_uv[AD4170_REFIN1P_SUP];
refn = st->vrefs_uv[AD4170_REFIN1N_SUP];
break;
case AD4170_REF_REFIN2:
if (st->vrefs_uv[AD4170_REFIN2P_SUP] == -ENODEV ||
st->vrefs_uv[AD4170_REFIN2N_SUP] == -ENODEV)
return dev_err_probe(dev, -ENODEV,
"REFIN2± selected but not provided\n");
refp = st->vrefs_uv[AD4170_REFIN2P_SUP];
refn = st->vrefs_uv[AD4170_REFIN2N_SUP];
break;
case AD4170_REF_AVDD:
refp = st->vrefs_uv[AD4170_AVDD_SUP];
refn = st->vrefs_uv[AD4170_AVSS_SUP];
break;
case AD4170_REF_REFOUT:
/* REFOUT is 2.5 V relative to AVSS */
refp = st->vrefs_uv[AD4170_AVSS_SUP] + AD4170_INT_REF_2_5V;
refn = st->vrefs_uv[AD4170_AVSS_SUP];
break;
default:
return -EINVAL;
}
/*
* Find out the analog input range from the channel type, polarity, and
* voltage reference selection.
* AD4170 channels are either differential or pseudo-differential.
* Diff input voltage range: −VREF/gain to +VREF/gain (datasheet page 6)
* Pseudo-diff input voltage range: 0 to VREF/gain (datasheet page 6)
*/
if (chan->differential) {
if (!bipolar)
return dev_err_probe(dev, -EINVAL,
"Channel %u differential unipolar\n",
ch_reg);
/*
* Differential bipolar channel.
* avss-supply is never above 0V.
* Assuming refin1n-supply not above 0V.
* Assuming refin2n-supply not above 0V.
*/
return refp + abs(refn);
}
/*
* Some configurations can lead to invalid setups.
* For example, if AVSS = -2.5V, REF_SELECT set to REFOUT (REFOUT/AVSS),
* and pseudo-diff channel configuration set, then the input range
* should go from 0V to +VREF (single-ended - datasheet pg 10), but
* REFOUT/AVSS range would be -2.5V to 0V.
* Check the positive reference is higher than 0V for pseudo-diff
* channels.
* Note that at this point in the code, refp can only be >= 0 since all
* error codes from reading the regulator voltage have been checked
* either at ad4170_regulator_setup() or above in this function.
*/
if (refp == 0)
return dev_err_probe(dev, -EINVAL,
"REF+ == GND for pseudo-diff chan %u\n",
ch_reg);
if (bipolar)
return refp;
/*
* Pseudo-differential unipolar channel.
* Input expected to swing from IN- to +VREF.
*/
ret = ad4170_get_ain_voltage_uv(st, chan->channel2, &ain_voltage);
if (ret)
return ret;
if (refp - ain_voltage <= 0)
return dev_err_probe(dev, -EINVAL,
"Negative input >= REF+ for pseudo-diff chan %u\n",
ch_reg);
return refp - ain_voltage;
}
static int __ad4170_read_sample(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan, int *val)
{
struct ad4170_state *st = iio_priv(indio_dev);
unsigned long settling_time_ms;
int ret;
reinit_completion(&st->completion);
ret = regmap_update_bits(st->regmap, AD4170_ADC_CTRL_REG,
AD4170_ADC_CTRL_MODE_MSK,
FIELD_PREP(AD4170_ADC_CTRL_MODE_MSK,
AD4170_ADC_CTRL_MODE_SINGLE));
if (ret)
return ret;
/*
* When a channel is manually selected by the user, the ADC needs an
* extra time to provide the first stable conversion. The ADC settling
* time depends on the filter type, filter frequency, and ADC clock
* frequency (see datasheet page 53). The maximum settling time among
* all filter configurations is 6291164 / fCLK. Use that formula to wait
* for sufficient time whatever the filter configuration may be.
*/
settling_time_ms = DIV_ROUND_UP(6291164 * MILLI, st->mclk_hz);
ret = wait_for_completion_timeout(&st->completion,
msecs_to_jiffies(settling_time_ms));
if (!ret)
dev_dbg(&st->spi->dev,
"No Data Ready signal. Reading after delay.\n");
ret = regmap_read(st->regmap, AD4170_DATA_24B_REG, val);
if (ret)
return ret;
if (chan->scan_type.sign == 's')
*val = sign_extend32(*val, chan->scan_type.realbits - 1);
return 0;
}
static int ad4170_read_sample(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan, int *val)
{
struct ad4170_state *st = iio_priv(indio_dev);
struct device *dev = &st->spi->dev;
int ret, ret2;
/*
* The ADC sequences through all enabled channels. That can lead to
* incorrect channel being sampled if a previous read would have left a
* different channel enabled. Thus, always enable and disable the
* channel on single-shot read.
*/
ret = ad4170_set_channel_enable(st, chan->address, true);
if (ret)
return ret;
ret = __ad4170_read_sample(indio_dev, chan, val);
if (ret) {
dev_err(dev, "failed to read sample: %d\n", ret);
ret2 = ad4170_set_channel_enable(st, chan->address, false);
if (ret2)
dev_err(dev, "failed to disable channel: %d\n", ret2);
return ret;
}
ret = ad4170_set_channel_enable(st, chan->address, false);
if (ret)
return ret;
return IIO_VAL_INT;
}
static int ad4170_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long info)
{
struct ad4170_state *st = iio_priv(indio_dev);
struct ad4170_chan_info *chan_info = &st->chan_infos[chan->address];
struct ad4170_setup *setup = &chan_info->setup;
enum ad4170_filter_type f_type;
unsigned int pga, fs_idx;
int ret;
guard(mutex)(&st->lock);
switch (info) {
case IIO_CHAN_INFO_RAW:
if (!iio_device_claim_direct(indio_dev))
return -EBUSY;
ret = ad4170_read_sample(indio_dev, chan, val);
iio_device_release_direct(indio_dev);
return ret;
case IIO_CHAN_INFO_SCALE:
pga = FIELD_GET(AD4170_AFE_PGA_GAIN_MSK, setup->afe);
switch (chan->type) {
case IIO_VOLTAGE:
*val = chan_info->scale_tbl[pga][0];
*val2 = chan_info->scale_tbl[pga][1];
return IIO_VAL_INT_PLUS_NANO;
case IIO_TEMP:
/*
* The scale_tbl converts output codes to mV units so
* multiply by MILLI to make the factor convert to µV.
* Then, apply the temperature sensor change sensitivity
* of 477 μV/K. Finally, multiply the result by MILLI
* again to comply with milli degrees Celsius IIO ABI.
*/
*val = 0;
*val2 = DIV_ROUND_CLOSEST(chan_info->scale_tbl[pga][1] * MILLI, 477) *
MILLI;
return IIO_VAL_INT_PLUS_NANO;
default:
return -EINVAL;
}
case IIO_CHAN_INFO_OFFSET:
pga = FIELD_GET(AD4170_AFE_PGA_GAIN_MSK, setup->afe);
*val = chan_info->offset_tbl[pga];
return IIO_VAL_INT;
case IIO_CHAN_INFO_SAMP_FREQ:
f_type = __ad4170_get_filter_type(setup->filter);
switch (f_type) {
case AD4170_SINC5_AVG:
case AD4170_SINC3:
fs_idx = find_closest(setup->filter_fs,
ad4170_sinc3_filt_fs_tbl,
ARRAY_SIZE(ad4170_sinc3_filt_fs_tbl));
*val = st->sps_tbl[f_type][fs_idx][0];
*val2 = st->sps_tbl[f_type][fs_idx][1];
return IIO_VAL_INT_PLUS_MICRO;
case AD4170_SINC5:
fs_idx = find_closest(setup->filter_fs,
ad4170_sinc5_filt_fs_tbl,
ARRAY_SIZE(ad4170_sinc5_filt_fs_tbl));
*val = st->sps_tbl[f_type][fs_idx][0];
*val2 = st->sps_tbl[f_type][fs_idx][1];
return IIO_VAL_INT_PLUS_MICRO;
default:
return -EINVAL;
}
case IIO_CHAN_INFO_CALIBBIAS:
*val = setup->offset;
return IIO_VAL_INT;
case IIO_CHAN_INFO_CALIBSCALE:
*val = setup->gain;
return IIO_VAL_INT;
default:
return -EINVAL;
}
}
static int ad4170_fill_scale_tbl(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan)
{
struct ad4170_state *st = iio_priv(indio_dev);
struct ad4170_chan_info *chan_info = &st->chan_infos[chan->address];
struct device *dev = &st->spi->dev;
int bipolar = chan->scan_type.sign == 's' ? 1 : 0;
int precision_bits = chan->scan_type.realbits;
int pga, ainm_voltage, ret;
unsigned long long offset;
ainm_voltage = 0;
ret = ad4170_get_ain_voltage_uv(st, chan->channel2, &ainm_voltage);
if (ret < 0)
return dev_err_probe(dev, ret, "Failed to fill scale table\n");
for (pga = 0; pga < AD4170_NUM_PGA_OPTIONS; pga++) {
u64 nv;
unsigned int lshift, rshift;
/*
* The PGA options are numbered from 0 to 9, with option 0 being
* a gain of 2^0 (no actual gain), and 7 meaning a gain of 2^7.
* Option 8, though, sets a gain of 0.5, so the input signal can
* be attenuated by 2 rather than amplified. Option 9, allows
* the signal to bypass the PGA circuitry (no gain).
*
* The scale factor to get ADC output codes to values in mV
* units is given by:
* _scale = (input_range / gain) / 2^precision
* AD4170 gain is a power of 2 so the above can be written as
* _scale = input_range / 2^(precision + gain)
* Keep the input range in µV to avoid truncating the less
* significant bits when right shifting it so to preserve scale
* precision.
*/
nv = (u64)chan_info->input_range_uv * NANO;
lshift = !!(pga & BIT(3)); /* handle PGA options 8 and 9 */
rshift = precision_bits - bipolar + (pga & GENMASK(2, 0)) - lshift;
chan_info->scale_tbl[pga][0] = 0;
chan_info->scale_tbl[pga][1] = div_u64(nv >> rshift, MILLI);
/*
* If the negative input is not at GND, the conversion result
* (which is relative to IN-) will be offset by the level at IN-.
* Use the scale factor the other way around to go from a known
* voltage to the corresponding ADC output code.
* With that, we are able to get to what would be the output
* code for the voltage at the negative input.
* If the negative input is not fixed, there is no offset.
*/
offset = ((unsigned long long)abs(ainm_voltage)) * MICRO;
offset = DIV_ROUND_CLOSEST_ULL(offset, chan_info->scale_tbl[pga][1]);
/*
* After divided by the scale, offset will always fit into 31
* bits. For _raw + _offset to be relative to GND, the value
* provided as _offset is of opposite sign than the real offset.
*/
if (ainm_voltage > 0)
chan_info->offset_tbl[pga] = -(int)(offset);
else
chan_info->offset_tbl[pga] = (int)(offset);
}
return 0;
}
static int ad4170_read_avail(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
const int **vals, int *type, int *length,
long info)
{
struct ad4170_state *st = iio_priv(indio_dev);
struct ad4170_chan_info *chan_info = &st->chan_infos[chan->address];
enum ad4170_filter_type f_type;
switch (info) {
case IIO_CHAN_INFO_SCALE:
*vals = (int *)chan_info->scale_tbl;
*length = ARRAY_SIZE(chan_info->scale_tbl) * 2;
*type = IIO_VAL_INT_PLUS_NANO;
return IIO_AVAIL_LIST;
case IIO_CHAN_INFO_SAMP_FREQ:
*type = IIO_VAL_INT_PLUS_MICRO;
f_type = ad4170_get_filter_type(indio_dev, chan);
switch (f_type) {
case AD4170_SINC5_AVG:
case AD4170_SINC3:
/* Read sps_tbl here to ensure in bounds array access */
*vals = (int *)st->sps_tbl[f_type];
*length = ARRAY_SIZE(ad4170_sinc3_filt_fs_tbl) * 2;
return IIO_AVAIL_LIST;
case AD4170_SINC5:
/* Read sps_tbl here to ensure in bounds array access */
*vals = (int *)st->sps_tbl[f_type];
*length = ARRAY_SIZE(ad4170_sinc5_filt_fs_tbl) * 2;
return IIO_AVAIL_LIST;
default:
return -EINVAL;
}
default:
return -EINVAL;
}
}
static int ad4170_set_pga(struct ad4170_state *st,
struct iio_chan_spec const *chan, int val, int val2)
{
struct ad4170_chan_info *chan_info = &st->chan_infos[chan->address];
struct ad4170_setup *setup = &chan_info->setup;
unsigned int pga;
for (pga = 0; pga < AD4170_NUM_PGA_OPTIONS; pga++) {
if (val == chan_info->scale_tbl[pga][0] &&
val2 == chan_info->scale_tbl[pga][1])
break;
}
if (pga == AD4170_NUM_PGA_OPTIONS)
return -EINVAL;
guard(mutex)(&st->lock);
setup->afe &= ~AD4170_AFE_PGA_GAIN_MSK;
setup->afe |= FIELD_PREP(AD4170_AFE_PGA_GAIN_MSK, pga);
return ad4170_write_channel_setup(st, chan->address, false);
}
static int ad4170_set_channel_freq(struct ad4170_state *st,
struct iio_chan_spec const *chan, int val,
int val2)
{
struct ad4170_chan_info *chan_info = &st->chan_infos[chan->address];
struct ad4170_setup *setup = &chan_info->setup;
enum ad4170_filter_type f_type = __ad4170_get_filter_type(setup->filter);
unsigned int filt_fs_tbl_size, i;
switch (f_type) {
case AD4170_SINC5_AVG:
case AD4170_SINC3:
filt_fs_tbl_size = ARRAY_SIZE(ad4170_sinc3_filt_fs_tbl);
break;
case AD4170_SINC5:
filt_fs_tbl_size = ARRAY_SIZE(ad4170_sinc5_filt_fs_tbl);
break;
}
for (i = 0; i < filt_fs_tbl_size; i++) {
if (st->sps_tbl[f_type][i][0] == val &&
st->sps_tbl[f_type][i][1] == val2)
break;
}
if (i == filt_fs_tbl_size)
return -EINVAL;
guard(mutex)(&st->lock);
if (f_type == AD4170_SINC5)
setup->filter_fs = ad4170_sinc5_filt_fs_tbl[i];
else
setup->filter_fs = ad4170_sinc3_filt_fs_tbl[i];
return ad4170_write_channel_setup(st, chan->address, false);
}
static int ad4170_set_calib_offset(struct ad4170_state *st,
struct iio_chan_spec const *chan, int val)
{
struct ad4170_chan_info *chan_info = &st->chan_infos[chan->address];
struct ad4170_setup *setup = &chan_info->setup;
guard(mutex)(&st->lock);
setup->offset = val;
return ad4170_write_channel_setup(st, chan->address, false);
}
static int ad4170_set_calib_gain(struct ad4170_state *st,
struct iio_chan_spec const *chan, int val)
{
struct ad4170_chan_info *chan_info = &st->chan_infos[chan->address];
struct ad4170_setup *setup = &chan_info->setup;
guard(mutex)(&st->lock);
setup->gain = val;
return ad4170_write_channel_setup(st, chan->address, false);
}
static int __ad4170_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan, int val,
int val2, long info)
{
struct ad4170_state *st = iio_priv(indio_dev);
switch (info) {
case IIO_CHAN_INFO_SCALE:
return ad4170_set_pga(st, chan, val, val2);
case IIO_CHAN_INFO_SAMP_FREQ:
return ad4170_set_channel_freq(st, chan, val, val2);
case IIO_CHAN_INFO_CALIBBIAS:
return ad4170_set_calib_offset(st, chan, val);
case IIO_CHAN_INFO_CALIBSCALE:
return ad4170_set_calib_gain(st, chan, val);
default:
return -EINVAL;
}
}
static int ad4170_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan, int val,
int val2, long info)
{
int ret;
if (!iio_device_claim_direct(indio_dev))
return -EBUSY;
ret = __ad4170_write_raw(indio_dev, chan, val, val2, info);
iio_device_release_direct(indio_dev);
return ret;
}
static int ad4170_write_raw_get_fmt(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
long info)
{
switch (info) {
case IIO_CHAN_INFO_SCALE:
return IIO_VAL_INT_PLUS_NANO;
case IIO_CHAN_INFO_SAMP_FREQ:
return IIO_VAL_INT_PLUS_MICRO;
case IIO_CHAN_INFO_CALIBBIAS:
case IIO_CHAN_INFO_CALIBSCALE:
return IIO_VAL_INT;
default:
return -EINVAL;
}
}
static int ad4170_update_scan_mode(struct iio_dev *indio_dev,
const unsigned long *active_scan_mask)
{
struct ad4170_state *st = iio_priv(indio_dev);
unsigned int chan_index;
int ret;
iio_for_each_active_channel(indio_dev, chan_index) {
ret = ad4170_set_channel_enable(st, chan_index, true);
if (ret)
return ret;
}
return 0;
}
static const struct iio_info ad4170_info = {
.read_raw = ad4170_read_raw,
.read_avail = ad4170_read_avail,
.write_raw = ad4170_write_raw,
.write_raw_get_fmt = ad4170_write_raw_get_fmt,
.update_scan_mode = ad4170_update_scan_mode,
.debugfs_reg_access = ad4170_debugfs_reg_access,
};
static int ad4170_soft_reset(struct ad4170_state *st)
{
int ret;
ret = regmap_write(st->regmap, AD4170_CONFIG_A_REG,
AD4170_SW_RESET_MSK);
if (ret)
return ret;
/* AD4170-4 requires 1 ms between reset and any register access. */
fsleep(1 * USEC_PER_MSEC);
return 0;
}
static int ad4170_gpio_get(struct gpio_chip *gc, unsigned int offset)
{
struct iio_dev *indio_dev = gpiochip_get_data(gc);
struct ad4170_state *st = iio_priv(indio_dev);
unsigned int val;
int ret;
if (!iio_device_claim_direct(indio_dev))
return -EBUSY;
ret = regmap_read(st->regmap, AD4170_GPIO_MODE_REG, &val);
if (ret)
goto err_release;
/*
* If the GPIO is configured as an input, read the current value from
* AD4170_GPIO_INPUT_REG. Otherwise, read the input value from
* AD4170_GPIO_OUTPUT_REG.
*/
if (val & BIT(offset * 2))
ret = regmap_read(st->regmap, AD4170_GPIO_INPUT_REG, &val);
else
ret = regmap_read(st->regmap, AD4170_GPIO_OUTPUT_REG, &val);
if (ret)
goto err_release;
ret = !!(val & BIT(offset));
err_release:
iio_device_release_direct(indio_dev);
return ret;
}
static int ad4170_gpio_set(struct gpio_chip *gc, unsigned int offset, int value)
{
struct iio_dev *indio_dev = gpiochip_get_data(gc);
struct ad4170_state *st = iio_priv(indio_dev);
int ret;
if (!iio_device_claim_direct(indio_dev))
return -EBUSY;
ret = regmap_assign_bits(st->regmap, AD4170_GPIO_OUTPUT_REG,
BIT(offset), !!value);
iio_device_release_direct(indio_dev);
return ret;
}
static int ad4170_gpio_get_direction(struct gpio_chip *gc, unsigned int offset)
{
struct iio_dev *indio_dev = gpiochip_get_data(gc);
struct ad4170_state *st = iio_priv(indio_dev);
unsigned int val;
int ret;
if (!iio_device_claim_direct(indio_dev))
return -EBUSY;
ret = regmap_read(st->regmap, AD4170_GPIO_MODE_REG, &val);
if (ret)
goto err_release;
if (val & BIT(offset * 2 + 1))
ret = GPIO_LINE_DIRECTION_OUT;
else
ret = GPIO_LINE_DIRECTION_IN;
err_release:
iio_device_release_direct(indio_dev);
return ret;
}
static int ad4170_gpio_direction_input(struct gpio_chip *gc, unsigned int offset)
{
struct iio_dev *indio_dev = gpiochip_get_data(gc);
struct ad4170_state *st = iio_priv(indio_dev);
unsigned long gpio_mask;
int ret;
if (!iio_device_claim_direct(indio_dev))
return -EBUSY;
switch (offset) {
case 0:
gpio_mask = AD4170_GPIO_MODE_GPIO0_MSK;
break;
case 1:
gpio_mask = AD4170_GPIO_MODE_GPIO1_MSK;
break;
case 2:
gpio_mask = AD4170_GPIO_MODE_GPIO2_MSK;
break;
case 3:
gpio_mask = AD4170_GPIO_MODE_GPIO3_MSK;
break;
default:
ret = -EINVAL;
goto err_release;
}
ret = regmap_update_bits(st->regmap, AD4170_GPIO_MODE_REG, gpio_mask,
AD4170_GPIO_MODE_GPIO_INPUT << (2 * offset));
err_release:
iio_device_release_direct(indio_dev);
return ret;
}
static int ad4170_gpio_direction_output(struct gpio_chip *gc,
unsigned int offset, int value)
{
struct iio_dev *indio_dev = gpiochip_get_data(gc);
struct ad4170_state *st = iio_priv(indio_dev);
unsigned long gpio_mask;
int ret;
ret = ad4170_gpio_set(gc, offset, value);
if (ret)
return ret;
if (!iio_device_claim_direct(indio_dev))
return -EBUSY;
switch (offset) {
case 0:
gpio_mask = AD4170_GPIO_MODE_GPIO0_MSK;
break;
case 1:
gpio_mask = AD4170_GPIO_MODE_GPIO1_MSK;
break;
case 2:
gpio_mask = AD4170_GPIO_MODE_GPIO2_MSK;
break;
case 3:
gpio_mask = AD4170_GPIO_MODE_GPIO3_MSK;
break;
default:
ret = -EINVAL;
goto err_release;
}
ret = regmap_update_bits(st->regmap, AD4170_GPIO_MODE_REG, gpio_mask,
AD4170_GPIO_MODE_GPIO_OUTPUT << (2 * offset));
err_release:
iio_device_release_direct(indio_dev);
return ret;
}
static int ad4170_gpio_init_valid_mask(struct gpio_chip *gc,
unsigned long *valid_mask,
unsigned int ngpios)
{
struct ad4170_state *st = gpiochip_get_data(gc);
unsigned int i;
/* Only expose GPIOs that were not assigned any other function. */
for (i = 0; i < ngpios; i++) {
bool valid = st->gpio_fn[i] == AD4170_GPIO_UNASSIGNED;
__assign_bit(i, valid_mask, valid);
}
return 0;
}
static int ad4170_gpio_init(struct iio_dev *indio_dev)
{
struct ad4170_state *st = iio_priv(indio_dev);
st->gpiochip.label = "ad4170_gpios";
st->gpiochip.base = -1;
st->gpiochip.ngpio = AD4170_NUM_GPIO_PINS;
st->gpiochip.parent = &st->spi->dev;
st->gpiochip.can_sleep = true;
st->gpiochip.init_valid_mask = ad4170_gpio_init_valid_mask;
st->gpiochip.get_direction = ad4170_gpio_get_direction;
st->gpiochip.direction_input = ad4170_gpio_direction_input;
st->gpiochip.direction_output = ad4170_gpio_direction_output;
st->gpiochip.get = ad4170_gpio_get;
st->gpiochip.set_rv = ad4170_gpio_set;
st->gpiochip.owner = THIS_MODULE;
return devm_gpiochip_add_data(&st->spi->dev, &st->gpiochip, indio_dev);
}
static int ad4170_validate_excitation_pin(struct ad4170_state *st, u32 pin)
{
struct device *dev = &st->spi->dev;
unsigned int i;
/* Check the pin number is valid */
for (i = 0; i < ARRAY_SIZE(ad4170_iout_pin_tbl); i++)
if (ad4170_iout_pin_tbl[i] == pin)
break;
if (i == ARRAY_SIZE(ad4170_iout_pin_tbl))
return dev_err_probe(dev, -EINVAL,
"Invalid excitation pin: %u\n",
pin);
/* Check the pin is available */
if (pin <= AD4170_MAX_ANALOG_PINS) {
if (st->pins_fn[pin] != AD4170_PIN_UNASSIGNED)
return dev_err_probe(dev, -EINVAL,
"Pin %u already used with fn %u\n",
pin, st->pins_fn[pin]);
st->pins_fn[pin] |= AD4170_PIN_CURRENT_OUT;
} else {
unsigned int gpio = pin - AD4170_CURRENT_SRC_I_OUT_PIN_GPIO(0);
if (st->gpio_fn[gpio] != AD4170_GPIO_UNASSIGNED)
return dev_err_probe(dev, -EINVAL,
"GPIO %u already used with fn %u\n",
gpio, st->gpio_fn[gpio]);
st->gpio_fn[gpio] |= AD4170_GPIO_AC_EXCITATION;
}
return 0;
}
static int ad4170_validate_excitation_pins(struct ad4170_state *st,
u32 *exc_pins, int num_exc_pins)
{
unsigned int i;
int ret;
for (i = 0; i < num_exc_pins; i++) {
ret = ad4170_validate_excitation_pin(st, exc_pins[i]);
if (ret)
return ret;
}
return 0;
}
static const char *const ad4170_i_out_pin_dt_props[] = {
"adi,excitation-pin-0",
"adi,excitation-pin-1",
"adi,excitation-pin-2",
"adi,excitation-pin-3",
};
static const char *const ad4170_i_out_val_dt_props[] = {
"adi,excitation-current-0-microamp",
"adi,excitation-current-1-microamp",
"adi,excitation-current-2-microamp",
"adi,excitation-current-3-microamp",
};
/*
* Parses firmware data describing output current source setup. There are 4
* excitation currents (IOUT0 to IOUT3) that can be configured independently.
* Excitation currents are added if they are output on the same pin.
*/
static int ad4170_parse_exc_current(struct ad4170_state *st,
struct fwnode_handle *child,
unsigned int *exc_pins,
unsigned int *exc_curs,
unsigned int *num_exc_pins)
{
struct device *dev = &st->spi->dev;
unsigned int num_pins, i, j;
u32 pin, val;
int ret;
num_pins = 0;
for (i = 0; i < AD4170_NUM_CURRENT_SRC; i++) {
/* Parse excitation current output pin properties. */
pin = AD4170_CURRENT_SRC_I_OUT_PIN_AIN(0);
ret = fwnode_property_read_u32(child, ad4170_i_out_pin_dt_props[i],
&pin);
if (ret)
continue;
exc_pins[num_pins] = pin;
/* Parse excitation current value properties. */
val = ad4170_iout_current_ua_tbl[0];
fwnode_property_read_u32(child,
ad4170_i_out_val_dt_props[i], &val);
for (j = 0; j < ARRAY_SIZE(ad4170_iout_current_ua_tbl); j++)
if (ad4170_iout_current_ua_tbl[j] == val)
break;
if (j == ARRAY_SIZE(ad4170_iout_current_ua_tbl))
return dev_err_probe(dev, -EINVAL, "Invalid %s: %uuA\n",
ad4170_i_out_val_dt_props[i], val);
exc_curs[num_pins] = j;
num_pins++;
}
*num_exc_pins = num_pins;
return 0;
}
static int ad4170_setup_current_src(struct ad4170_state *st,
struct fwnode_handle *child,
struct ad4170_setup *setup, u32 *exc_pins,
unsigned int *exc_curs, int num_exc_pins,
bool ac_excited)
{
unsigned int exc_cur_pair, i, j;
int ret;
for (i = 0; i < num_exc_pins; i++) {
unsigned int exc_cur = exc_curs[i];
unsigned int pin = exc_pins[i];
unsigned int current_src = 0;
for (j = 0; j < AD4170_NUM_CURRENT_SRC; j++)
if (st->cur_src_pins[j] == AD4170_CURRENT_SRC_DISABLED)
break;
if (j == AD4170_NUM_CURRENT_SRC)
return dev_err_probe(&st->spi->dev, -EINVAL,
"Too many excitation current sources\n");
current_src |= FIELD_PREP(AD4170_CURRENT_SRC_I_OUT_PIN_MSK, pin);
current_src |= FIELD_PREP(AD4170_CURRENT_SRC_I_OUT_VAL_MSK, exc_cur);
st->cur_src_pins[j] = pin;
ret = regmap_write(st->regmap, AD4170_CURRENT_SRC_REG(j),
current_src);
if (ret)
return ret;
}
if (!ac_excited)
return 0;
if (num_exc_pins < 2)
return dev_err_probe(&st->spi->dev, -EINVAL,
"Current chopping requested but only one pin provided: %u\n",
exc_pins[0]);
/*
* Two use cases to handle here:
* - 2 pairs of excitation currents;
* - 1 pair of excitation currents.
*/
if (num_exc_pins == 4) {
for (i = 0; i < AD4170_NUM_CURRENT_SRC; i++)
if (st->cur_src_pins[i] != exc_pins[i])
return dev_err_probe(&st->spi->dev, -EINVAL,
"Unable to use 4 exc pins\n");
} else {
/*
* Excitation current chopping is configured in pairs. Current
* sources IOUT0 and IOUT1 form pair 1, IOUT2 and IOUT3 make up
* pair 2. So, if current chopping was requested, check if the
* first end of the first pair of excitation currents is
* available. Try the next pair if IOUT0 has already been
* configured for another channel.
*/
i = st->cur_src_pins[0] == exc_pins[0] ? 0 : 2;
if (st->cur_src_pins[i] != exc_pins[0] ||
st->cur_src_pins[i + 1] != exc_pins[1])
return dev_err_probe(&st->spi->dev, -EINVAL,
"Failed to setup current chopping\n");
st->cur_src_pins[i] = exc_pins[0];
st->cur_src_pins[i + 1] = exc_pins[1];
if (i == 0)
exc_cur_pair = AD4170_MISC_CHOP_IEXC_PAIR1;
else
exc_cur_pair = AD4170_MISC_CHOP_IEXC_PAIR2;
}
/*
* Configure excitation current chopping.
* Chop both pairs if using four excitation pins.
*/
setup->misc |= FIELD_PREP(AD4170_MISC_CHOP_IEXC_MSK,
num_exc_pins == 2 ?
exc_cur_pair :
AD4170_MISC_CHOP_IEXC_BOTH);
return 0;
}
static int ad4170_setup_bridge(struct ad4170_state *st,
struct fwnode_handle *child,
struct ad4170_setup *setup, u32 *exc_pins,
unsigned int *exc_curs, int num_exc_pins,
bool ac_excited)
{
unsigned long gpio_mask;
unsigned int i;
int ret;
/*
* If a specific current is provided through
* adi,excitation-current-n-microamp, set excitation pins provided
* through adi,excitation-pin-n to excite the bridge circuit.
*/
for (i = 0; i < num_exc_pins; i++)
if (exc_curs[i] > 0)
return ad4170_setup_current_src(st, child, setup, exc_pins,
exc_curs, num_exc_pins,
ac_excited);
/*
* Else, use predefined ACX1, ACX1 negated, ACX2, ACX2 negated signals
* to AC excite the bridge. Those signals are output on GPIO2, GPIO0,
* GPIO3, and GPIO1, respectively. If only two pins are specified for AC
* excitation, use ACX1 and ACX2 (GPIO2 and GPIO3).
*
* Also, to avoid any short-circuit condition when more than one channel
* is enabled, set GPIO2 and GPIO0 high, and set GPIO1 and GPIO3 low to
* DC excite the bridge whenever a channel without AC excitation is
* selected. That is needed because GPIO pins are controlled by the next
* highest priority GPIO function when a channel doesn't enable AC
* excitation. See datasheet Figure 113 Weigh Scale (AC Excitation) for
* the reference circuit diagram.
*/
if (num_exc_pins == 2) {
setup->misc |= FIELD_PREP(AD4170_MISC_CHOP_ADC_MSK, 0x3);
gpio_mask = AD4170_GPIO_MODE_GPIO3_MSK | AD4170_GPIO_MODE_GPIO2_MSK;
ret = regmap_update_bits(st->regmap, AD4170_GPIO_MODE_REG, gpio_mask,
FIELD_PREP(AD4170_GPIO_MODE_GPIO3_MSK,
AD4170_GPIO_MODE_GPIO_OUTPUT) |
FIELD_PREP(AD4170_GPIO_MODE_GPIO2_MSK,
AD4170_GPIO_MODE_GPIO_OUTPUT));
if (ret)
return ret;
/*
* Set GPIO2 high and GPIO3 low to DC excite the bridge when
* a different channel is selected.
*/
gpio_mask = AD4170_GPIO_OUTPUT_GPIO_MSK(3) |
AD4170_GPIO_OUTPUT_GPIO_MSK(2);
ret = regmap_update_bits(st->regmap, AD4170_GPIO_OUTPUT_REG, gpio_mask,
FIELD_PREP(AD4170_GPIO_OUTPUT_GPIO_MSK(3), 0) |
FIELD_PREP(AD4170_GPIO_OUTPUT_GPIO_MSK(2), 1));
if (ret)
return ret;
st->gpio_fn[3] |= AD4170_GPIO_OUTPUT;
st->gpio_fn[2] |= AD4170_GPIO_OUTPUT;
} else {
setup->misc |= FIELD_PREP(AD4170_MISC_CHOP_ADC_MSK, 0x2);
gpio_mask = AD4170_GPIO_MODE_GPIO3_MSK | AD4170_GPIO_MODE_GPIO2_MSK |
AD4170_GPIO_MODE_GPIO1_MSK | AD4170_GPIO_MODE_GPIO0_MSK;
ret = regmap_update_bits(st->regmap, AD4170_GPIO_MODE_REG, gpio_mask,
FIELD_PREP(AD4170_GPIO_MODE_GPIO3_MSK,
AD4170_GPIO_MODE_GPIO_OUTPUT) |
FIELD_PREP(AD4170_GPIO_MODE_GPIO2_MSK,
AD4170_GPIO_MODE_GPIO_OUTPUT) |
FIELD_PREP(AD4170_GPIO_MODE_GPIO1_MSK,
AD4170_GPIO_MODE_GPIO_OUTPUT) |
FIELD_PREP(AD4170_GPIO_MODE_GPIO0_MSK,
AD4170_GPIO_MODE_GPIO_OUTPUT));
if (ret)
return ret;
/*
* Set GPIO2 and GPIO0 high, and set GPIO1 and GPIO3 low to DC
* excite the bridge when a different channel is selected.
*/
gpio_mask = AD4170_GPIO_OUTPUT_GPIO_MSK(3) |
AD4170_GPIO_OUTPUT_GPIO_MSK(2) |
AD4170_GPIO_OUTPUT_GPIO_MSK(1) |
AD4170_GPIO_OUTPUT_GPIO_MSK(0);
ret = regmap_update_bits(st->regmap, AD4170_GPIO_OUTPUT_REG, gpio_mask,
FIELD_PREP(AD4170_GPIO_OUTPUT_GPIO_MSK(3), 0) |
FIELD_PREP(AD4170_GPIO_OUTPUT_GPIO_MSK(2), 1) |
FIELD_PREP(AD4170_GPIO_OUTPUT_GPIO_MSK(1), 0) |
FIELD_PREP(AD4170_GPIO_OUTPUT_GPIO_MSK(0), 1));
if (ret)
return ret;
st->gpio_fn[3] |= AD4170_GPIO_OUTPUT;
st->gpio_fn[2] |= AD4170_GPIO_OUTPUT;
st->gpio_fn[1] |= AD4170_GPIO_OUTPUT;
st->gpio_fn[0] |= AD4170_GPIO_OUTPUT;
}
return 0;
}
static int ad4170_setup_rtd(struct ad4170_state *st,
struct fwnode_handle *child,
struct ad4170_setup *setup, u32 *exc_pins,
unsigned int *exc_curs, int num_exc_pins, bool ac_excited)
{
return ad4170_setup_current_src(st, child, setup, exc_pins,
exc_curs, num_exc_pins, ac_excited);
}
static int ad4170_parse_external_sensor(struct ad4170_state *st,
struct fwnode_handle *child,
struct ad4170_setup *setup,
struct iio_chan_spec *chan,
unsigned int s_type)
{
unsigned int num_exc_pins, reg_val;
struct device *dev = &st->spi->dev;
u32 pins[2], exc_pins[4], exc_curs[4];
bool ac_excited;
int ret;
ret = fwnode_property_read_u32_array(child, "diff-channels", pins,
ARRAY_SIZE(pins));
if (ret)
return dev_err_probe(dev, ret,
"Failed to read sensor diff-channels\n");
chan->differential = true;
chan->channel = pins[0];
chan->channel2 = pins[1];
ret = ad4170_parse_exc_current(st, child, exc_pins, exc_curs, &num_exc_pins);
if (ret)
return ret;
/* The external sensor may not need excitation from the ADC chip. */
if (num_exc_pins == 0)
return 0;
ret = ad4170_validate_excitation_pins(st, exc_pins, num_exc_pins);
if (ret)
return ret;
ac_excited = fwnode_property_read_bool(child, "adi,excitation-ac");
if (s_type == AD4170_THERMOCOUPLE_SENSOR) {
if (st->pins_fn[chan->channel2] & AD4170_PIN_VBIAS) {
reg_val = BIT(chan->channel2);
ret = regmap_write(st->regmap, AD4170_V_BIAS_REG, reg_val);
if (ret)
dev_err_probe(dev, ret, "Failed to set vbias\n");
}
}
if (s_type == AD4170_WEIGH_SCALE_SENSOR)
ret = ad4170_setup_bridge(st, child, setup, exc_pins, exc_curs,
num_exc_pins, ac_excited);
else
ret = ad4170_setup_rtd(st, child, setup, exc_pins, exc_curs,
num_exc_pins, ac_excited);
return ret;
}
static int ad4170_parse_reference(struct ad4170_state *st,
struct fwnode_handle *child,
struct ad4170_setup *setup)
{
struct device *dev = &st->spi->dev;
const char *propname;
u32 aux;
int ret;
/* Optional positive reference buffering */
propname = "adi,positive-reference-buffer";
ret = device_property_match_property_string(dev, propname,
ad4170_ref_buf_str,
ARRAY_SIZE(ad4170_ref_buf_str));
/* Default to full precharge buffer enabled. */
setup->afe |= FIELD_PREP(AD4170_AFE_REF_BUF_P_MSK,
ret >= 0 ? ret : AD4170_REF_BUF_FULL);
/* Optional negative reference buffering */
propname = "adi,negative-reference-buffer";
ret = device_property_match_property_string(dev, propname,
ad4170_ref_buf_str,
ARRAY_SIZE(ad4170_ref_buf_str));
/* Default to full precharge buffer enabled. */
setup->afe |= FIELD_PREP(AD4170_AFE_REF_BUF_M_MSK,
ret >= 0 ? ret : AD4170_REF_BUF_FULL);
/* Optional voltage reference selection */
propname = "adi,reference-select";
aux = AD4170_REF_REFOUT; /* Default reference selection. */
fwnode_property_read_u32(child, propname, &aux);
if (aux > AD4170_REF_AVDD)
return dev_err_probe(dev, -EINVAL, "Invalid %s: %u\n",
propname, aux);
setup->afe |= FIELD_PREP(AD4170_AFE_REF_SELECT_MSK, aux);
return 0;
}
static int ad4170_parse_adc_channel_type(struct device *dev,
struct fwnode_handle *child,
struct iio_chan_spec *chan)
{
const char *propname, *propname2;
int ret, ret2;
u32 pins[2];
propname = "single-channel";
propname2 = "diff-channels";
if (!fwnode_property_present(child, propname) &&
!fwnode_property_present(child, propname2))
return dev_err_probe(dev, -EINVAL,
"Channel must define one of %s or %s.\n",
propname, propname2);
/* Parse differential channel configuration */
ret = fwnode_property_read_u32_array(child, propname2, pins,
ARRAY_SIZE(pins));
if (!ret) {
chan->differential = true;
chan->channel = pins[0];
chan->channel2 = pins[1];
return 0;
}
/* Failed to parse diff chan so try pseudo-diff chan props */
propname2 = "common-mode-channel";
if (fwnode_property_present(child, propname) &&
!fwnode_property_present(child, propname2))
return dev_err_probe(dev, -EINVAL,
"When %s is defined, %s must be defined too\n",
propname, propname2);
/* Parse pseudo-differential channel configuration */
ret = fwnode_property_read_u32(child, propname, &pins[0]);
ret2 = fwnode_property_read_u32(child, propname2, &pins[1]);
if (!ret && !ret2) {
chan->differential = false;
chan->channel = pins[0];
chan->channel2 = pins[1];
return 0;
}
return dev_err_probe(dev, -EINVAL,
"Failed to parse channel %lu input. %d, %d\n",
chan->address, ret, ret2);
}
static int ad4170_parse_channel_node(struct iio_dev *indio_dev,
struct fwnode_handle *child,
unsigned int chan_num)
{
struct ad4170_state *st = iio_priv(indio_dev);
unsigned int s_type = AD4170_ADC_SENSOR;
struct device *dev = &st->spi->dev;
struct ad4170_chan_info *chan_info;
struct ad4170_setup *setup;
struct iio_chan_spec *chan;
unsigned int ref_select;
unsigned int ch_reg;
bool bipolar;
int ret;
ret = fwnode_property_read_u32(child, "reg", &ch_reg);
if (ret)
return dev_err_probe(dev, ret, "Failed to read channel reg\n");
if (ch_reg >= AD4170_MAX_ADC_CHANNELS)
return dev_err_probe(dev, -EINVAL,
"Channel idx greater than no of channels\n");
chan = &st->chans[chan_num];
*chan = ad4170_channel_template;
chan->address = ch_reg;
chan->scan_index = ch_reg;
chan_info = &st->chan_infos[chan->address];
chan_info->setup_num = AD4170_INVALID_SETUP;
chan_info->initialized = true;
setup = &chan_info->setup;
ret = ad4170_parse_reference(st, child, setup);
if (ret)
return ret;
ret = fwnode_property_match_property_string(child, "adi,sensor-type",
ad4170_sensor_type,
ARRAY_SIZE(ad4170_sensor_type));
/* Default to conventional ADC channel if sensor type not present */
s_type = ret < 0 ? AD4170_ADC_SENSOR : ret;
switch (s_type) {
case AD4170_ADC_SENSOR:
ret = ad4170_parse_adc_channel_type(dev, child, chan);
if (ret)
return ret;
break;
case AD4170_WEIGH_SCALE_SENSOR:
case AD4170_THERMOCOUPLE_SENSOR:
case AD4170_RTD_SENSOR:
ret = ad4170_parse_external_sensor(st, child, setup, chan, s_type);
if (ret)
return ret;
break;
default:
return -EINVAL;
}
bipolar = fwnode_property_read_bool(child, "bipolar");
setup->afe |= FIELD_PREP(AD4170_AFE_BIPOLAR_MSK, bipolar);
if (bipolar)
chan->scan_type.sign = 's';
else
chan->scan_type.sign = 'u';
ret = ad4170_validate_channel(st, chan);
if (ret)
return ret;
ref_select = FIELD_GET(AD4170_AFE_REF_SELECT_MSK, setup->afe);
ret = ad4170_get_input_range(st, chan, ch_reg, ref_select);
if (ret < 0)
return dev_err_probe(dev, ret, "Invalid input config\n");
chan_info->input_range_uv = ret;
return 0;
}
static int ad4170_parse_channels(struct iio_dev *indio_dev)
{
struct ad4170_state *st = iio_priv(indio_dev);
struct device *dev = &st->spi->dev;
unsigned int num_channels;
unsigned int chan_num;
int ret;
num_channels = device_get_child_node_count(dev);
if (num_channels > AD4170_MAX_ADC_CHANNELS)
return dev_err_probe(dev, -EINVAL, "Too many channels\n");
/* Add one for temperature */
num_channels = min(num_channels + 1, AD4170_MAX_ADC_CHANNELS);
chan_num = 0;
device_for_each_child_node_scoped(dev, child) {
ret = ad4170_parse_channel_node(indio_dev, child, chan_num++);
if (ret)
return ret;
}
/*
* Add internal temperature sensor channel if the maximum number of
* channels has not been reached.
*/
if (num_channels < AD4170_MAX_ADC_CHANNELS) {
struct ad4170_setup *setup = &st->chan_infos[chan_num].setup;
st->chans[chan_num] = ad4170_temp_channel_template;
st->chans[chan_num].address = chan_num;
st->chans[chan_num].scan_index = chan_num;
st->chan_infos[chan_num].setup_num = AD4170_INVALID_SETUP;
st->chan_infos[chan_num].initialized = true;
setup->afe |= FIELD_PREP(AD4170_AFE_REF_SELECT_MSK,
AD4170_REF_AVDD);
ret = ad4170_get_input_range(st, &st->chans[chan_num], chan_num,
AD4170_REF_AVDD);
if (ret < 0)
return dev_err_probe(dev, ret, "Invalid input config\n");
st->chan_infos[chan_num].input_range_uv = ret;
chan_num++;
}
/* Add timestamp channel */
struct iio_chan_spec ts_chan = IIO_CHAN_SOFT_TIMESTAMP(chan_num);
st->chans[chan_num] = ts_chan;
num_channels = num_channels + 1;
indio_dev->num_channels = num_channels;
indio_dev->channels = st->chans;
return 0;
}
static struct ad4170_state *clk_hw_to_ad4170(struct clk_hw *hw)
{
return container_of(hw, struct ad4170_state, int_clk_hw);
}
static unsigned long ad4170_sel_clk(struct ad4170_state *st,
unsigned int clk_sel)
{
st->clock_ctrl &= ~AD4170_CLOCK_CTRL_CLOCKSEL_MSK;
st->clock_ctrl |= FIELD_PREP(AD4170_CLOCK_CTRL_CLOCKSEL_MSK, clk_sel);
return regmap_write(st->regmap, AD4170_CLOCK_CTRL_REG, st->clock_ctrl);
}
static unsigned long ad4170_clk_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
return AD4170_INT_CLOCK_16MHZ;
}
static int ad4170_clk_output_is_enabled(struct clk_hw *hw)
{
struct ad4170_state *st = clk_hw_to_ad4170(hw);
u32 clk_sel;
clk_sel = FIELD_GET(AD4170_CLOCK_CTRL_CLOCKSEL_MSK, st->clock_ctrl);
return clk_sel == AD4170_CLOCK_CTRL_CLOCKSEL_INT_OUT;
}
static int ad4170_clk_output_prepare(struct clk_hw *hw)
{
struct ad4170_state *st = clk_hw_to_ad4170(hw);
return ad4170_sel_clk(st, AD4170_CLOCK_CTRL_CLOCKSEL_INT_OUT);
}
static void ad4170_clk_output_unprepare(struct clk_hw *hw)
{
struct ad4170_state *st = clk_hw_to_ad4170(hw);
ad4170_sel_clk(st, AD4170_CLOCK_CTRL_CLOCKSEL_INT);
}
static const struct clk_ops ad4170_int_clk_ops = {
.recalc_rate = ad4170_clk_recalc_rate,
.is_enabled = ad4170_clk_output_is_enabled,
.prepare = ad4170_clk_output_prepare,
.unprepare = ad4170_clk_output_unprepare,
};
static int ad4170_register_clk_provider(struct iio_dev *indio_dev)
{
struct ad4170_state *st = iio_priv(indio_dev);
struct device *dev = indio_dev->dev.parent;
struct clk_init_data init = {};
int ret;
if (device_property_read_string(dev, "clock-output-names", &init.name)) {
init.name = devm_kasprintf(dev, GFP_KERNEL, "%pfw",
dev_fwnode(dev));
if (!init.name)
return -ENOMEM;
}
init.ops = &ad4170_int_clk_ops;
st->int_clk_hw.init = &init;
ret = devm_clk_hw_register(dev, &st->int_clk_hw);
if (ret)
return ret;
return devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get,
&st->int_clk_hw);
}
static int ad4170_clock_select(struct iio_dev *indio_dev)
{
struct ad4170_state *st = iio_priv(indio_dev);
struct device *dev = &st->spi->dev;
struct clk *ext_clk;
int ret;
ext_clk = devm_clk_get_optional_enabled(dev, NULL);
if (IS_ERR(ext_clk))
return dev_err_probe(dev, PTR_ERR(ext_clk),
"Failed to get external clock\n");
if (!ext_clk) {
/* Use internal clock reference */
st->mclk_hz = AD4170_INT_CLOCK_16MHZ;
st->clock_ctrl |= FIELD_PREP(AD4170_CLOCK_CTRL_CLOCKSEL_MSK,
AD4170_CLOCK_CTRL_CLOCKSEL_INT_OUT);
if (!device_property_present(&st->spi->dev, "#clock-cells"))
return 0;
return ad4170_register_clk_provider(indio_dev);
}
/* Read optional clock-names prop to specify the external clock type */
ret = device_property_match_property_string(dev, "clock-names",
ad4170_clk_sel,
ARRAY_SIZE(ad4170_clk_sel));
ret = ret < 0 ? 0 : ret; /* Default to external clock if no clock-names */
st->clock_ctrl |= FIELD_PREP(AD4170_CLOCK_CTRL_CLOCKSEL_MSK,
AD4170_CLOCK_CTRL_CLOCKSEL_EXT + ret);
st->mclk_hz = clk_get_rate(ext_clk);
if (st->mclk_hz < AD4170_EXT_CLOCK_MHZ_MIN ||
st->mclk_hz > AD4170_EXT_CLOCK_MHZ_MAX) {
return dev_err_probe(dev, -EINVAL,
"Invalid external clock frequency %u\n",
st->mclk_hz);
}
return 0;
}
static int ad4170_parse_firmware(struct iio_dev *indio_dev)
{
unsigned int vbias_pins[AD4170_MAX_ANALOG_PINS];
struct ad4170_state *st = iio_priv(indio_dev);
struct device *dev = &st->spi->dev;
unsigned int num_vbias_pins;
int reg_data, ret;
u32 int_pin_sel;
unsigned int i;
ret = ad4170_clock_select(indio_dev);
if (ret)
return dev_err_probe(dev, ret, "Failed to setup device clock\n");
ret = regmap_write(st->regmap, AD4170_CLOCK_CTRL_REG, st->clock_ctrl);
if (ret)
return ret;
for (i = 0; i < AD4170_NUM_CURRENT_SRC; i++)
st->cur_src_pins[i] = AD4170_CURRENT_SRC_DISABLED;
/* On power on, device defaults to using SDO pin for data ready signal */
int_pin_sel = AD4170_INT_PIN_SDO;
ret = device_property_match_property_string(dev, "interrupt-names",
ad4170_int_pin_names,
ARRAY_SIZE(ad4170_int_pin_names));
if (ret >= 0)
int_pin_sel = ret;
reg_data = FIELD_PREP(AD4170_PIN_MUXING_DIG_AUX1_CTRL_MSK,
int_pin_sel == AD4170_INT_PIN_DIG_AUX1 ?
AD4170_PIN_MUXING_DIG_AUX1_RDY :
AD4170_PIN_MUXING_DIG_AUX1_DISABLED);
ret = regmap_update_bits(st->regmap, AD4170_PIN_MUXING_REG,
AD4170_PIN_MUXING_DIG_AUX1_CTRL_MSK, reg_data);
if (ret)
return ret;
ret = device_property_count_u32(dev, "adi,vbias-pins");
if (ret > 0) {
if (ret > AD4170_MAX_ANALOG_PINS)
return dev_err_probe(dev, -EINVAL,
"Too many vbias pins %u\n", ret);
num_vbias_pins = ret;
ret = device_property_read_u32_array(dev, "adi,vbias-pins",
vbias_pins,
num_vbias_pins);
if (ret)
return dev_err_probe(dev, ret,
"Failed to read vbias pins\n");
for (i = 0; i < num_vbias_pins; i++)
st->pins_fn[vbias_pins[i]] |= AD4170_PIN_VBIAS;
}
ret = ad4170_parse_channels(indio_dev);
if (ret)
return ret;
/* Only create a GPIO chip if flagged for it */
if (device_property_read_bool(dev, "gpio-controller")) {
ret = ad4170_gpio_init(indio_dev);
if (ret)
return ret;
}
return 0;
}
static int ad4170_initial_config(struct iio_dev *indio_dev)
{
struct ad4170_state *st = iio_priv(indio_dev);
struct device *dev = &st->spi->dev;
unsigned int i;
int ret;
ad4170_fill_sps_tbl(st);
ret = regmap_update_bits(st->regmap, AD4170_ADC_CTRL_REG,
AD4170_ADC_CTRL_MODE_MSK,
FIELD_PREP(AD4170_ADC_CTRL_MODE_MSK,
AD4170_ADC_CTRL_MODE_IDLE));
if (ret)
return dev_err_probe(dev, ret,
"Failed to set ADC mode to idle\n");
for (i = 0; i < indio_dev->num_channels; i++) {
struct ad4170_chan_info *chan_info;
struct iio_chan_spec const *chan;
struct ad4170_setup *setup;
unsigned int val;
chan = &indio_dev->channels[i];
if (chan->type == IIO_TIMESTAMP)
continue;
chan_info = &st->chan_infos[chan->address];
setup = &chan_info->setup;
setup->gain = AD4170_GAIN_REG_DEFAULT;
ret = ad4170_write_channel_setup(st, chan->address, false);
if (ret)
return dev_err_probe(dev, ret,
"Failed to write channel setup\n");
val = FIELD_PREP(AD4170_CHAN_MAP_AINP_MSK, chan->channel) |
FIELD_PREP(AD4170_CHAN_MAP_AINM_MSK, chan->channel2);
ret = regmap_write(st->regmap, AD4170_CHAN_MAP_REG(i), val);
if (ret)
return dev_err_probe(dev, ret,
"Failed to write CHAN_MAP_REG\n");
ret = ad4170_set_channel_freq(st, chan,
AD4170_DEFAULT_SAMP_RATE, 0);
if (ret)
return dev_err_probe(dev, ret,
"Failed to set channel freq\n");
ret = ad4170_fill_scale_tbl(indio_dev, chan);
if (ret)
return dev_err_probe(dev, ret,
"Failed to fill scale tbl\n");
}
/* Disable all channels to avoid reading from unexpected channel */
ret = regmap_write(st->regmap, AD4170_CHAN_EN_REG, 0);
if (ret)
return dev_err_probe(dev, ret,
"Failed to disable channels\n");
/*
* Configure channels to share the same data output register, i.e. data
* can be read from the same register address regardless of channel
* number.
*/
return regmap_update_bits(st->regmap, AD4170_ADC_CTRL_REG,
AD4170_ADC_CTRL_MULTI_DATA_REG_SEL_MSK,
AD4170_ADC_CTRL_MULTI_DATA_REG_SEL_MSK);
}
static int ad4170_prepare_spi_message(struct ad4170_state *st)
{
/*
* Continuous data register read is enabled on buffer postenable so
* no instruction phase is needed meaning we don't need to send the
* register address to read data. Transfer only needs the read buffer.
*/
st->xfer.rx_buf = &st->rx_buf;
st->xfer.len = BITS_TO_BYTES(ad4170_channel_template.scan_type.realbits);
spi_message_init_with_transfers(&st->msg, &st->xfer, 1);
return devm_spi_optimize_message(&st->spi->dev, st->spi, &st->msg);
}
static int ad4170_buffer_postenable(struct iio_dev *indio_dev)
{
struct ad4170_state *st = iio_priv(indio_dev);
int ret;
ret = regmap_update_bits(st->regmap, AD4170_ADC_CTRL_REG,
AD4170_ADC_CTRL_MODE_MSK,
FIELD_PREP(AD4170_ADC_CTRL_MODE_MSK,
AD4170_ADC_CTRL_MODE_CONT));
if (ret)
return ret;
/*
* This enables continuous read of the ADC data register. The ADC must
* be in continuous conversion mode.
*/
return regmap_update_bits(st->regmap, AD4170_ADC_CTRL_REG,
AD4170_ADC_CTRL_CONT_READ_MSK,
FIELD_PREP(AD4170_ADC_CTRL_CONT_READ_MSK,
AD4170_ADC_CTRL_CONT_READ_ENABLE));
}
static int ad4170_buffer_predisable(struct iio_dev *indio_dev)
{
struct ad4170_state *st = iio_priv(indio_dev);
unsigned int i;
int ret;
/*
* Use a high register address (virtual register) to request a write of
* 0xA5 to the ADC during the first 8 SCLKs of the ADC data read cycle,
* thus exiting continuous read.
*/
ret = regmap_write(st->regmap, AD4170_ADC_CTRL_CONT_READ_EXIT_REG, 0);
if (ret)
return ret;
ret = regmap_update_bits(st->regmap, AD4170_ADC_CTRL_REG,
AD4170_ADC_CTRL_CONT_READ_MSK,
FIELD_PREP(AD4170_ADC_CTRL_CONT_READ_MSK,
AD4170_ADC_CTRL_CONT_READ_DISABLE));
if (ret)
return ret;
ret = regmap_update_bits(st->regmap, AD4170_ADC_CTRL_REG,
AD4170_ADC_CTRL_MODE_MSK,
FIELD_PREP(AD4170_ADC_CTRL_MODE_MSK,
AD4170_ADC_CTRL_MODE_IDLE));
if (ret)
return ret;
/*
* The ADC sequences through all the enabled channels (see datasheet
* page 95). That can lead to incorrect channel being read if a
* single-shot read (or buffered read with different active_scan_mask)
* is done after buffer disable. Disable all channels so only requested
* channels will be read.
*/
for (i = 0; i < indio_dev->num_channels; i++) {
if (indio_dev->channels[i].type == IIO_TIMESTAMP)
continue;
ret = ad4170_set_channel_enable(st, i, false);
if (ret)
return ret;
}
return 0;
}
static bool ad4170_validate_scan_mask(struct iio_dev *indio_dev,
const unsigned long *scan_mask)
{
unsigned int masklength = iio_get_masklength(indio_dev);
unsigned int enabled;
/*
* The channel sequencer cycles through the enabled channels in
* sequential order, from channel 0 to channel 15, bypassing disabled
* channels. When more than one channel is enabled, channel 0 must
* always be enabled. See datasheet channel_en register description at
* page 95.
*/
enabled = bitmap_weight(scan_mask, masklength);
if (enabled > 1)
return test_bit(0, scan_mask);
return enabled == 1;
}
static const struct iio_buffer_setup_ops ad4170_buffer_ops = {
.postenable = ad4170_buffer_postenable,
.predisable = ad4170_buffer_predisable,
.validate_scan_mask = ad4170_validate_scan_mask,
};
static irqreturn_t ad4170_trigger_handler(int irq, void *p)
{
struct iio_poll_func *pf = p;
struct iio_dev *indio_dev = pf->indio_dev;
struct ad4170_state *st = iio_priv(indio_dev);
unsigned int chan_index;
unsigned int i = 0;
int ret;
iio_for_each_active_channel(indio_dev, chan_index) {
ret = spi_sync(st->spi, &st->msg);
if (ret)
goto err_out;
memcpy(&st->bounce_buffer[i++], st->rx_buf, ARRAY_SIZE(st->rx_buf));
}
iio_push_to_buffers_with_ts(indio_dev, st->bounce_buffer,
sizeof(st->bounce_buffer),
iio_get_time_ns(indio_dev));
err_out:
iio_trigger_notify_done(indio_dev->trig);
return IRQ_HANDLED;
}
static const struct iio_trigger_ops ad4170_trigger_ops = {
.validate_device = iio_trigger_validate_own_device,
};
static irqreturn_t ad4170_irq_handler(int irq, void *dev_id)
{
struct iio_dev *indio_dev = dev_id;
struct ad4170_state *st = iio_priv(indio_dev);
if (iio_buffer_enabled(indio_dev))
iio_trigger_poll(st->trig);
else
complete(&st->completion);
return IRQ_HANDLED;
};
static int ad4170_trigger_setup(struct iio_dev *indio_dev)
{
struct ad4170_state *st = iio_priv(indio_dev);
struct device *dev = &st->spi->dev;
int ret;
st->trig = devm_iio_trigger_alloc(dev, "%s-trig%d",
indio_dev->name,
iio_device_id(indio_dev));
if (!st->trig)
return -ENOMEM;
st->trig->ops = &ad4170_trigger_ops;
iio_trigger_set_drvdata(st->trig, indio_dev);
ret = devm_iio_trigger_register(dev, st->trig);
if (ret)
return dev_err_probe(dev, ret, "Failed to register trigger\n");
indio_dev->trig = iio_trigger_get(st->trig);
return 0;
}
static int ad4170_regulator_setup(struct ad4170_state *st)
{
struct device *dev = &st->spi->dev;
int ret;
/* Required regulators */
ret = devm_regulator_get_enable_read_voltage(dev, "avdd");
if (ret < 0)
return dev_err_probe(dev, ret, "Failed to get AVDD voltage.\n");
st->vrefs_uv[AD4170_AVDD_SUP] = ret;
ret = devm_regulator_get_enable_read_voltage(dev, "iovdd");
if (ret < 0)
return dev_err_probe(dev, ret, "Failed to get IOVDD voltage.\n");
st->vrefs_uv[AD4170_IOVDD_SUP] = ret;
/* Optional regulators */
ret = devm_regulator_get_enable_read_voltage(dev, "avss");
if (ret < 0 && ret != -ENODEV)
return dev_err_probe(dev, ret, "Failed to get AVSS voltage.\n");
/*
* Assume AVSS at GND (0V) if not provided.
* REVISIT: AVSS is never above system ground level (i.e. AVSS is either
* GND or a negative voltage). But we currently don't have support for
* reading negative voltages with the regulator framework. So, the
* current AD4170 support reads a positive value from the regulator,
* then inverts sign to make that negative.
*/
st->vrefs_uv[AD4170_AVSS_SUP] = ret == -ENODEV ? 0 : -ret;
ret = devm_regulator_get_enable_read_voltage(dev, "refin1p");
if (ret < 0 && ret != -ENODEV)
return dev_err_probe(dev, ret, "Failed to get REFIN+ voltage.\n");
st->vrefs_uv[AD4170_REFIN1P_SUP] = ret;
ret = devm_regulator_get_enable_read_voltage(dev, "refin1n");
if (ret < 0 && ret != -ENODEV)
return dev_err_probe(dev, ret, "Failed to get REFIN- voltage.\n");
/*
* Negative supplies are assumed to provide negative voltage.
* REVISIT when support for negative regulator voltage read be available
* in the regulator framework.
*/
st->vrefs_uv[AD4170_REFIN1N_SUP] = ret == -ENODEV ? -ENODEV : -ret;
ret = devm_regulator_get_enable_read_voltage(dev, "refin2p");
if (ret < 0 && ret != -ENODEV)
return dev_err_probe(dev, ret, "Failed to get REFIN2+ voltage.\n");
st->vrefs_uv[AD4170_REFIN2P_SUP] = ret;
ret = devm_regulator_get_enable_read_voltage(dev, "refin2n");
if (ret < 0 && ret != -ENODEV)
return dev_err_probe(dev, ret, "Failed to get REFIN2- voltage.\n");
/*
* Negative supplies are assumed to provide negative voltage.
* REVISIT when support for negative regulator voltage read be available
* in the regulator framework.
*/
st->vrefs_uv[AD4170_REFIN2N_SUP] = ret == -ENODEV ? -ENODEV : -ret;
return 0;
}
static int ad4170_probe(struct spi_device *spi)
{
const struct ad4170_chip_info *chip;
struct device *dev = &spi->dev;
struct iio_dev *indio_dev;
struct ad4170_state *st;
int ret;
indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
if (!indio_dev)
return -ENOMEM;
st = iio_priv(indio_dev);
st->spi = spi;
ret = devm_mutex_init(dev, &st->lock);
if (ret)
return ret;
chip = spi_get_device_match_data(spi);
if (!chip)
return -EINVAL;
indio_dev->name = chip->name;
indio_dev->info = &ad4170_info;
st->regmap = devm_regmap_init(dev, NULL, st, &ad4170_regmap_config);
if (IS_ERR(st->regmap))
return dev_err_probe(dev, PTR_ERR(st->regmap),
"Failed to initialize regmap\n");
ret = ad4170_regulator_setup(st);
if (ret)
return ret;
ret = ad4170_soft_reset(st);
if (ret)
return ret;
ret = ad4170_parse_firmware(indio_dev);
if (ret)
return dev_err_probe(dev, ret, "Failed to parse firmware\n");
ret = ad4170_initial_config(indio_dev);
if (ret)
return dev_err_probe(dev, ret, "Failed to setup device\n");
init_completion(&st->completion);
if (spi->irq) {
ret = devm_request_irq(dev, spi->irq, &ad4170_irq_handler,
IRQF_ONESHOT, indio_dev->name, indio_dev);
if (ret)
return ret;
ret = ad4170_trigger_setup(indio_dev);
if (ret)
return ret;
}
ret = ad4170_prepare_spi_message(st);
if (ret)
return dev_err_probe(dev, ret, "Failed to prepare SPI message\n");
ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
&ad4170_trigger_handler,
&ad4170_buffer_ops);
if (ret)
return dev_err_probe(dev, ret, "Failed to setup read buffer\n");
return devm_iio_device_register(dev, indio_dev);
}
static const struct spi_device_id ad4170_id_table[] = {
{ "ad4170-4", (kernel_ulong_t)&ad4170_chip_info },
{ "ad4190-4", (kernel_ulong_t)&ad4190_chip_info },
{ "ad4195-4", (kernel_ulong_t)&ad4195_chip_info },
{ }
};
MODULE_DEVICE_TABLE(spi, ad4170_id_table);
static const struct of_device_id ad4170_of_match[] = {
{ .compatible = "adi,ad4170-4", .data = &ad4170_chip_info },
{ .compatible = "adi,ad4190-4", .data = &ad4190_chip_info },
{ .compatible = "adi,ad4195-4", .data = &ad4195_chip_info },
{ }
};
MODULE_DEVICE_TABLE(of, ad4170_of_match);
static struct spi_driver ad4170_driver = {
.driver = {
.name = "ad4170-4",
.of_match_table = ad4170_of_match,
},
.probe = ad4170_probe,
.id_table = ad4170_id_table,
};
module_spi_driver(ad4170_driver);
MODULE_AUTHOR("Ana-Maria Cusco <ana-maria.cusco@analog.com>");
MODULE_AUTHOR("Marcelo Schmitt <marcelo.schmitt@analog.com>");
MODULE_DESCRIPTION("Analog Devices AD4170 SPI driver");
MODULE_LICENSE("GPL");
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