Re: [PATCH v11 2/2] iio: adc: ad7173: add AD7173 driver

Jonathan Cameron
2024-01-13T14:59:55Z

On Wed, 20 Dec 2023 12:48:05 +0200
Dumitru Ceclan <mitrutzceclan@gmail.com> wrote:

> The AD7173 family offer a complete integrated Sigma-Delta ADC solution
> which can be used in high precision, low noise single channel
> applications or higher speed multiplexed applications. The Sigma-Delta
> ADC is intended primarily for measurement of signals close to DC but also
> delivers outstanding performance with input bandwidths out to ~10kHz.
>
> Reviewed-by: Andy Shevchenko <andy@kernel.org>
> Reviewed-by: Michael Walle <michael@walle.cc> # for gpio-regmap
> Signed-off-by: Dumitru Ceclan <mitrutzceclan@gmail.com>

Was missing import of the IIO_AD_SIGMA_DELTA namespace. I've
fixed that whilst applying.

Applied to the togreg branch of iio.git and pushed out as testing
for 0-day to get a head start before rc1 when I'll rebase the tree
and push it out for next to pick up.

Thanks,

Jonathan

> ---
>
> V10-> V11 <no changes>
> V9 -> V10 <no changes>
> V8 -> V9
> - Add '(x)' to some macro's definition to reduce NO of checks
> - Use reg 0 constant definition in debug_reg_access()
> - Rename channels_st_priv_arr to chans_st_arr
> - Remove unnecessary u32 cast from read_raw()
> - Compute read_raw() offset instead of constant
> - Add offset comments to data rate arrays
> - Removed redundant newline in _parse_channel_config()
> V7 -> V8
> - remove Kconfig commas
> - reorder include <...gpio/regmap.h>
> - GPO12_DATA(x) from BIT(x) -> BIT(x+0)
> - use the same pointer to dev in ad7173_setup()
> - rewrite temp channel read_raw scale for better readability
> - add comment to explain temp channel offset
> - follow multi-line comment style
> - change ref_sel type to signed int
> - use fwnode_property_match_property_string()
> V6 -> V7
> - format Kconfig supported models using '-'
> - include types.h instead of stddef.h
> - change device_info->num_gpios type to u8
> - reorder fields in ad7173_state, place ad_sigma_delta
> - reorder fields in ad7173_device_info, group by type
> - add default case in read_raw()
> - rename ad7173_debug() to ad7173_debug_reg_access()
> - remove explicit u8 cast
> - remove return 0; for offset in read_raw()
> - add '\n' to error messages
> - reorder probe variables -> reversed xmas tree
> - remove redundant inner commas in of_match and id_table
> - simplify selected reference code by setting default value and ignoring
> fwnode_property_read_string() error
> - use match_string() for finding selected reference
> - err on no channels specified
> - add missing fwnode_handle_put(child) on err return branches
> - remove spi_set_drvdata() from probe
> - remove offset variable from find_live_config(), not used
> - add comment showing a generic LRU implementation might be used if one
> will exist
> - MISC: add blank line to chanel_config struct, trailing comma ref_sel_str[],
> remove blank line in update_scan_mode(), add spaces around '/'
> V5->V6 <no changes>
> V4 -> V5
> - List Kconfig supported models one per line
> - Include <array_size.h> and <container_of.h>
> - Remove bits.h and kernel.h include
> - Add spaces before '\' on multi-line definitions
> - Change constant definition name from "..._MICROV" to "..._uV"
> - Change ad7173_channel_config attributes order for grouping by type
> - Remove redundant {} in ad7173_gpio_init()
> - Add array with reference select strings
> - Change parsing of device tree adi,reference-select from integer to string
> - Change indentation for ad7173_find_live_config() header
> - Use struct_group() in config struct
> - Use offsetofend() and sizeof_field() in ad7173_find_live_config()
> - Split line on logic operator in ad7173_find_live_config() at configs comparison
> - Use IDA for config slots allocation
> - Reverse xmas tree order for probe local variables
> - Use BIT() for computing bipolar channels offset
> - Change (MICRO/MILLI) to MILLI in read_raw for integer part of sampling frequency
> - MISC: remove blank line, use 0 value dirrectly, one line statement devm_kcalloc()
> V3 -> V4
> - cleaned up includes
> - add ad7173_gpio_disable(), include to devm actions
> - remove iio_device_claim_direct_mode() from update_scan_mode()
> - always set differential iio_chan attribute to true, retain bipolar info only in private struct
> - store multiple regulators in state for voltage references
> - compute read_raw offset depending on channel used reference
> - configure channel setup using selected reference
> - add ad7173_get_ref_voltage_milli()
> - clean up ad7173_fw_sparse_channel_config() changing array access of channel structs to pointers
> - retain chip name in st->info structure
> - use spi_device_get_match_data() in probe
> V2 -> V3
> - change Kconfig GPIO_REGMAP and REGMAP_SPI to be conditioned by GPIOLIB
> - cast chip info to (kernel_ulong_t) to suppress warnings
> - adjust copyright year to reflect the out-of-tree history
> - remove unused sysfs and trigger header files
> - clean up defined macros by using FIELD_PREP( ) inline
> - use DECLARE_BITMAP( ) for defiining cfg_slots_status
> - use clear/set _bit instead of assign_bit
> - rename state field regmap to reg_gpiocon_regmap to better represent usage
> - replace container_of( ) usages to ad_sigma_delta_to_ad7173( )
> - improve readability of sampling frequency conversion in write_raw( )
> specifying conversion from Micro to Milli
> - use iio_device_claim_direct_mode( ) correctly in write_raw( )
> - flip logic in write_raw( ) to reduce line length
> - pass only state struct to gpio_init function
> - remove else branch at end of probe
> - remove comma after list terminator for of_match and id_table arrays
> - clarify write_raw( ) realbits 32 bit size check in a comment
> - change parsed fw property 'adi,bipolar' to 'bipolar' to matched referenced adc.yaml
> - use reg_set_base for gpio regmap xlate
> V1 -> V2
> - keep original out-of-tree AD7173 naming
> - remove gpio_cleanup
> - handle 32bit realbits offset case
> - use iio_device_claim_direct_mode, drop own mutex
> - use dev_err_probe
> - cleanup headers include
> - use GENMASK() and FIELD_PREP()
> - use HZ_PER_MHZ
> - change #ifdef GPIOLIB to if( IS_ENABLED(CONFIG_GPIOLIB))
> - use gpio-regmap
> - change boolean flag in info struct to number of gpios
> - NIH memset64
> - use struct pointers for config comparison
> - use spi_write_then_read for ADC reset
> - use stack allocated buffer for reset
> - define constant for reset sequence size
> - use kcalloc instead of kzalloc
> - change of naming to fw of dt parse function
> - change de-referencing chain to local variable dev in multiple locations
> - drop write_raw_get_fmt
> - add driver private data to spi_device_id table
> - use fsleep() instead of usleep_range()
> - put config value inline
> - align read/write raw arguments
> - remove zeroed values from channel templates structure
> - define constants for temperature sensor positive and negative inputs
> - always enable temperature channel
> - configure spi clock phase and polarity from driver
> misc changes (test bit, return disable all, indentation fix, change statements to single line)
>
> drivers/iio/adc/Kconfig | 17 +
> drivers/iio/adc/Makefile | 1 +
> drivers/iio/adc/ad7173.c | 974 +++++++++++++++++++++++++++++++++++++++
> 3 files changed, 992 insertions(+)
> create mode 100644 drivers/iio/adc/ad7173.c
>
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> index 1e2b7a2c67c6..1d7b9ade4d59 100644
> --- a/drivers/iio/adc/Kconfig
> +++ b/drivers/iio/adc/Kconfig
> @@ -54,6 +54,23 @@ config AD7124
> To compile this driver as a module, choose M here: the module will be
> called ad7124.
>
> +config AD7173
> + tristate "Analog Devices AD7173 driver"
> + depends on SPI_MASTER
> + select AD_SIGMA_DELTA
> + select GPIO_REGMAP if GPIOLIB
> + select REGMAP_SPI if GPIOLIB
> + help
> + Say yes here to build support for Analog Devices AD7173 and similar ADC
> + Currently supported models:
> + - AD7172-2
> + - AD7173-8
> + - AD7175-2
> + - AD7176-2
> +
> + To compile this driver as a module, choose M here: the module will be
> + called ad7173.
> +
> config AD7192
> tristate "Analog Devices AD7190 AD7192 AD7193 AD7195 ADC driver"
> depends on SPI
> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
> index c0803383a7cc..12e723cdc1f1 100644
> --- a/drivers/iio/adc/Makefile
> +++ b/drivers/iio/adc/Makefile
> @@ -9,6 +9,7 @@ obj-$(CONFIG_AD_SIGMA_DELTA) += ad_sigma_delta.o
> obj-$(CONFIG_AD4130) += ad4130.o
> obj-$(CONFIG_AD7091R5) += ad7091r5.o ad7091r-base.o
> obj-$(CONFIG_AD7124) += ad7124.o
> +obj-$(CONFIG_AD7173) += ad7173.o
> obj-$(CONFIG_AD7192) += ad7192.o
> obj-$(CONFIG_AD7266) += ad7266.o
> obj-$(CONFIG_AD7280) += ad7280a.o
> diff --git a/drivers/iio/adc/ad7173.c b/drivers/iio/adc/ad7173.c
> new file mode 100644
> index 000000000000..7a7e8262f189
> --- /dev/null
> +++ b/drivers/iio/adc/ad7173.c
> @@ -0,0 +1,974 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * AD7172-2/AD7173-8/AD7175-2/AD7176-2 SPI ADC driver
> + * Copyright (C) 2015, 2023 Analog Devices, Inc.
> + */
> +
> +#include <linux/array_size.h>
> +#include <linux/bitfield.h>
> +#include <linux/bitmap.h>
> +#include <linux/container_of.h>
> +#include <linux/delay.h>
> +#include <linux/device.h>
> +#include <linux/err.h>
> +#include <linux/gpio/driver.h>
> +#include <linux/gpio/regmap.h>
> +#include <linux/idr.h>
> +#include <linux/interrupt.h>
> +#include <linux/math64.h>
> +#include <linux/module.h>
> +#include <linux/mod_devicetable.h>
> +#include <linux/property.h>
> +#include <linux/regmap.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/slab.h>
> +#include <linux/spi/spi.h>
> +#include <linux/types.h>
> +#include <linux/units.h>
> +
> +#include <linux/iio/buffer.h>
> +#include <linux/iio/iio.h>
> +#include <linux/iio/trigger_consumer.h>
> +#include <linux/iio/triggered_buffer.h>
> +
> +#include <linux/iio/adc/ad_sigma_delta.h>
> +
> +#define AD7173_REG_COMMS 0x00
> +#define AD7173_REG_ADC_MODE 0x01
> +#define AD7173_REG_INTERFACE_MODE 0x02
> +#define AD7173_REG_CRC 0x03
> +#define AD7173_REG_DATA 0x04
> +#define AD7173_REG_GPIO 0x06
> +#define AD7173_REG_ID 0x07
> +#define AD7173_REG_CH(x) (0x10 + (x))
> +#define AD7173_REG_SETUP(x) (0x20 + (x))
> +#define AD7173_REG_FILTER(x) (0x28 + (x))
> +#define AD7173_REG_OFFSET(x) (0x30 + (x))
> +#define AD7173_REG_GAIN(x) (0x38 + (x))
> +
> +#define AD7173_RESET_LENGTH BITS_TO_BYTES(64)
> +
> +#define AD7173_CH_ENABLE BIT(15)
> +#define AD7173_CH_SETUP_SEL_MASK GENMASK(14, 12)
> +#define AD7173_CH_SETUP_AINPOS_MASK GENMASK(9, 5)
> +#define AD7173_CH_SETUP_AINNEG_MASK GENMASK(4, 0)
> +
> +#define AD7173_CH_ADDRESS(pos, neg) \
> + (FIELD_PREP(AD7173_CH_SETUP_AINPOS_MASK, pos) | \
> + FIELD_PREP(AD7173_CH_SETUP_AINNEG_MASK, neg))
> +#define AD7173_AIN_TEMP_POS 17
> +#define AD7173_AIN_TEMP_NEG 18
> +
> +#define AD7172_ID 0x00d0
> +#define AD7173_ID 0x30d0
> +#define AD7175_ID 0x0cd0
> +#define AD7176_ID 0x0c90
> +#define AD7173_ID_MASK GENMASK(15, 4)
> +
> +#define AD7173_ADC_MODE_REF_EN BIT(15)
> +#define AD7173_ADC_MODE_SING_CYC BIT(13)
> +#define AD7173_ADC_MODE_MODE_MASK GENMASK(6, 4)
> +#define AD7173_ADC_MODE_CLOCKSEL_MASK GENMASK(3, 2)
> +
> +#define AD7173_GPIO_PDSW BIT(14)
> +#define AD7173_GPIO_OP_EN2_3 BIT(13)
> +#define AD7173_GPIO_MUX_IO BIT(12)
> +#define AD7173_GPIO_SYNC_EN BIT(11)
> +#define AD7173_GPIO_ERR_EN BIT(10)
> +#define AD7173_GPIO_ERR_DAT BIT(9)
> +#define AD7173_GPIO_GP_DATA3 BIT(7)
> +#define AD7173_GPIO_GP_DATA2 BIT(6)
> +#define AD7173_GPIO_IP_EN1 BIT(5)
> +#define AD7173_GPIO_IP_EN0 BIT(4)
> +#define AD7173_GPIO_OP_EN1 BIT(3)
> +#define AD7173_GPIO_OP_EN0 BIT(2)
> +#define AD7173_GPIO_GP_DATA1 BIT(1)
> +#define AD7173_GPIO_GP_DATA0 BIT(0)
> +
> +#define AD7173_GPO12_DATA(x) BIT((x) + 0)
> +#define AD7173_GPO23_DATA(x) BIT((x) + 4)
> +#define AD7173_GPO_DATA(x) ((x) < 2 ? AD7173_GPO12_DATA(x) : AD7173_GPO23_DATA(x))
> +
> +#define AD7173_INTERFACE_DATA_STAT BIT(6)
> +#define AD7173_INTERFACE_DATA_STAT_EN(x) \
> + FIELD_PREP(AD7173_INTERFACE_DATA_STAT, x)
> +
> +#define AD7173_SETUP_BIPOLAR BIT(12)
> +#define AD7173_SETUP_AREF_BUF_MASK GENMASK(11, 10)
> +#define AD7173_SETUP_AIN_BUF_MASK GENMASK(9, 8)
> +
> +#define AD7173_SETUP_REF_SEL_MASK GENMASK(5, 4)
> +#define AD7173_SETUP_REF_SEL_AVDD1_AVSS 0x3
> +#define AD7173_SETUP_REF_SEL_INT_REF 0x2
> +#define AD7173_SETUP_REF_SEL_EXT_REF2 0x1
> +#define AD7173_SETUP_REF_SEL_EXT_REF 0x0
> +#define AD7173_VOLTAGE_INT_REF_uV 2500000
> +#define AD7173_TEMP_SENSIIVITY_uV_per_C 477
> +
> +#define AD7173_FILTER_ODR0_MASK GENMASK(5, 0)
> +#define AD7173_MAX_CONFIGS 8
> +
> +enum ad7173_ids {
> + ID_AD7172_2,
> + ID_AD7173_8,
> + ID_AD7175_2,
> + ID_AD7176_2,
> +};
> +
> +struct ad7173_device_info {
> + const unsigned int *sinc5_data_rates;
> + unsigned int num_sinc5_data_rates;
> + unsigned int num_channels;
> + unsigned int num_configs;
> + unsigned int num_inputs;
> + unsigned int clock;
> + unsigned int id;
> + char *name;
> + bool has_temp;
> + u8 num_gpios;
> +};
> +
> +struct ad7173_channel_config {
> + u8 cfg_slot;
> + bool live;
> +
> + /* Following fields are used to compare equality. */
> + struct_group(config_props,
> + bool bipolar;
> + bool input_buf;
> + u8 odr;
> + u8 ref_sel;
> + );
> +};
> +
> +struct ad7173_channel {
> + unsigned int chan_reg;
> + unsigned int ain;
> + struct ad7173_channel_config cfg;
> +};
> +
> +struct ad7173_state {
> + struct ad_sigma_delta sd;
> + const struct ad7173_device_info *info;
> + struct ad7173_channel *channels;
> + struct regulator_bulk_data regulators[3];
> + unsigned int adc_mode;
> + unsigned int interface_mode;
> + unsigned int num_channels;
> + struct ida cfg_slots_status;
> + unsigned long long config_usage_counter;
> + unsigned long long *config_cnts;
> +#if IS_ENABLED(CONFIG_GPIOLIB)
> + struct regmap *reg_gpiocon_regmap;
> + struct gpio_regmap *gpio_regmap;
> +#endif
> +};
> +
> +static const unsigned int ad7173_sinc5_data_rates[] = {
> + 6211000, 6211000, 6211000, 6211000, 6211000, 6211000, 5181000, 4444000, /* 0-7 */
> + 3115000, 2597000, 1007000, 503800, 381000, 200300, 100500, 59520, /* 8-15 */
> + 49680, 20010, 16333, 10000, 5000, 2500, 1250, /* 16-22 */
> +};
> +
> +static const unsigned int ad7175_sinc5_data_rates[] = {
> + 50000000, 41667000, 31250000, 27778000, /* 0-3 */
> + 20833000, 17857000, 12500000, 10000000, /* 4-7 */
> + 5000000, 2500000, 1000000, 500000, /* 8-11 */
> + 397500, 200000, 100000, 59920, /* 12-15 */
> + 49960, 20000, 16666, 10000, /* 16-19 */
> + 5000, /* 20 */
> +};
> +
> +static const struct ad7173_device_info ad7173_device_info[] = {
> + [ID_AD7172_2] = {
> + .name = "ad7172-2",
> + .id = AD7172_ID,
> + .num_inputs = 5,
> + .num_channels = 4,
> + .num_configs = 4,
> + .num_gpios = 2,
> + .has_temp = true,
> + .clock = 2 * HZ_PER_MHZ,
> + .sinc5_data_rates = ad7173_sinc5_data_rates,
> + .num_sinc5_data_rates = ARRAY_SIZE(ad7173_sinc5_data_rates),
> + },
> + [ID_AD7173_8] = {
> + .name = "ad7173-8",
> + .id = AD7173_ID,
> + .num_inputs = 17,
> + .num_channels = 16,
> + .num_configs = 8,
> + .num_gpios = 4,
> + .has_temp = true,
> + .clock = 2 * HZ_PER_MHZ,
> + .sinc5_data_rates = ad7173_sinc5_data_rates,
> + .num_sinc5_data_rates = ARRAY_SIZE(ad7173_sinc5_data_rates),
> + },
> + [ID_AD7175_2] = {
> + .name = "ad7175-2",
> + .id = AD7175_ID,
> + .num_inputs = 5,
> + .num_channels = 4,
> + .num_configs = 4,
> + .num_gpios = 2,
> + .has_temp = true,
> + .clock = 16 * HZ_PER_MHZ,
> + .sinc5_data_rates = ad7175_sinc5_data_rates,
> + .num_sinc5_data_rates = ARRAY_SIZE(ad7175_sinc5_data_rates),
> + },
> + [ID_AD7176_2] = {
> + .name = "ad7176-2",
> + .id = AD7176_ID,
> + .num_inputs = 5,
> + .num_channels = 4,
> + .num_configs = 4,
> + .num_gpios = 2,
> + .has_temp = false,
> + .clock = 16 * HZ_PER_MHZ,
> + .sinc5_data_rates = ad7175_sinc5_data_rates,
> + .num_sinc5_data_rates = ARRAY_SIZE(ad7175_sinc5_data_rates),
> + },
> +};
> +
> +static const char *const ad7173_ref_sel_str[] = {
> + [AD7173_SETUP_REF_SEL_EXT_REF] = "refin",
> + [AD7173_SETUP_REF_SEL_EXT_REF2] = "refin2",
> + [AD7173_SETUP_REF_SEL_INT_REF] = "refout-avss",
> + [AD7173_SETUP_REF_SEL_AVDD1_AVSS] = "avdd",
> +};
> +
> +#if IS_ENABLED(CONFIG_GPIOLIB)
> +
> +static const struct regmap_range ad7173_range_gpio[] = {
> + regmap_reg_range(AD7173_REG_GPIO, AD7173_REG_GPIO),
> +};
> +
> +static const struct regmap_access_table ad7173_access_table = {
> + .yes_ranges = ad7173_range_gpio,
> + .n_yes_ranges = ARRAY_SIZE(ad7173_range_gpio),
> +};
> +
> +static const struct regmap_config ad7173_regmap_config = {
> + .reg_bits = 8,
> + .val_bits = 16,
> + .rd_table = &ad7173_access_table,
> + .wr_table = &ad7173_access_table,
> + .read_flag_mask = BIT(6),
> +};
> +
> +static int ad7173_mask_xlate(struct gpio_regmap *gpio, unsigned int base,
> + unsigned int offset, unsigned int *reg,
> + unsigned int *mask)
> +{
> + *mask = AD7173_GPO_DATA(offset);
> + *reg = base;
> + return 0;
> +}
> +
> +static void ad7173_gpio_disable(void *data)
> +{
> + struct ad7173_state *st = data;
> + unsigned int mask;
> +
> + mask = AD7173_GPIO_OP_EN0 | AD7173_GPIO_OP_EN1 | AD7173_GPIO_OP_EN2_3;
> + regmap_update_bits(st->reg_gpiocon_regmap, AD7173_REG_GPIO, mask, ~mask);
> +}
> +
> +static int ad7173_gpio_init(struct ad7173_state *st)
> +{
> + struct gpio_regmap_config gpio_regmap = {};
> + struct device *dev = &st->sd.spi->dev;
> + unsigned int mask;
> + int ret;
> +
> + st->reg_gpiocon_regmap = devm_regmap_init_spi(st->sd.spi, &ad7173_regmap_config);
> + ret = PTR_ERR_OR_ZERO(st->reg_gpiocon_regmap);
> + if (ret)
> + return dev_err_probe(dev, ret, "Unable to init regmap\n");
> +
> + mask = AD7173_GPIO_OP_EN0 | AD7173_GPIO_OP_EN1 | AD7173_GPIO_OP_EN2_3;
> + regmap_update_bits(st->reg_gpiocon_regmap, AD7173_REG_GPIO, mask, mask);
> +
> + ret = devm_add_action_or_reset(dev, ad7173_gpio_disable, st);
> + if (ret)
> + return ret;
> +
> + gpio_regmap.parent = dev;
> + gpio_regmap.regmap = st->reg_gpiocon_regmap;
> + gpio_regmap.ngpio = st->info->num_gpios;
> + gpio_regmap.reg_set_base = AD7173_REG_GPIO;
> + gpio_regmap.reg_mask_xlate = ad7173_mask_xlate;
> +
> + st->gpio_regmap = devm_gpio_regmap_register(dev, &gpio_regmap);
> + ret = PTR_ERR_OR_ZERO(st->gpio_regmap);
> + if (ret)
> + return dev_err_probe(dev, ret, "Unable to init gpio-regmap\n");
> +
> + return 0;
> +}
> +
> +#endif /* CONFIG_GPIOLIB */
> +
> +static struct ad7173_state *ad_sigma_delta_to_ad7173(struct ad_sigma_delta *sd)
> +{
> + return container_of(sd, struct ad7173_state, sd);
> +}
> +
> +static void ad7173_ida_destroy(void *data)
> +{
> + struct ad7173_state *st = data;
> +
> + ida_destroy(&st->cfg_slots_status);
> +}
> +
> +static void ad7173_reset_usage_cnts(struct ad7173_state *st)
> +{
> + memset64(st->config_cnts, 0, st->info->num_configs);
> + st->config_usage_counter = 0;
> +}
> +
> +static struct ad7173_channel_config *
> +ad7173_find_live_config(struct ad7173_state *st, struct ad7173_channel_config *cfg)
> +{
> + struct ad7173_channel_config *cfg_aux;
> + ptrdiff_t cmp_size;
> + int i;
> +
> + cmp_size = sizeof_field(struct ad7173_channel_config, config_props);
> + for (i = 0; i < st->num_channels; i++) {
> + cfg_aux = &st->channels[i].cfg;
> +
> + if (cfg_aux->live &&
> + !memcmp(&cfg->config_props, &cfg_aux->config_props, cmp_size))
> + return cfg_aux;
> + }
> + return NULL;
> +}
> +
> +/* Could be replaced with a generic LRU implementation */
> +static int ad7173_free_config_slot_lru(struct ad7173_state *st)
> +{
> + int i, lru_position = 0;
> +
> + for (i = 1; i < st->info->num_configs; i++)
> + if (st->config_cnts[i] < st->config_cnts[lru_position])
> + lru_position = i;
> +
> + for (i = 0; i < st->num_channels; i++)
> + if (st->channels[i].cfg.cfg_slot == lru_position)
> + st->channels[i].cfg.live = false;
> +
> + ida_free(&st->cfg_slots_status, lru_position);
> + return ida_alloc(&st->cfg_slots_status, GFP_KERNEL);
> +}
> +
> +/* Could be replaced with a generic LRU implementation */
> +static int ad7173_load_config(struct ad7173_state *st,
> + struct ad7173_channel_config *cfg)
> +{
> + unsigned int config;
> + int free_cfg_slot, ret;
> +
> + free_cfg_slot = ida_alloc_range(&st->cfg_slots_status, 0,
> + st->info->num_configs - 1, GFP_KERNEL);
> + if (free_cfg_slot < 0)
> + free_cfg_slot = ad7173_free_config_slot_lru(st);
> +
> + cfg->cfg_slot = free_cfg_slot;
> + config = FIELD_PREP(AD7173_SETUP_REF_SEL_MASK, cfg->ref_sel);
> +
> + if (cfg->bipolar)
> + config |= AD7173_SETUP_BIPOLAR;
> +
> + if (cfg->input_buf)
> + config |= AD7173_SETUP_AIN_BUF_MASK;
> +
> + ret = ad_sd_write_reg(&st->sd, AD7173_REG_SETUP(free_cfg_slot), 2, config);
> + if (ret)
> + return ret;
> +
> + return ad_sd_write_reg(&st->sd, AD7173_REG_FILTER(free_cfg_slot), 2,
> + AD7173_FILTER_ODR0_MASK & cfg->odr);
> +}
> +
> +static int ad7173_config_channel(struct ad7173_state *st, int addr)
> +{
> + struct ad7173_channel_config *cfg = &st->channels[addr].cfg;
> + struct ad7173_channel_config *live_cfg;
> + int ret;
> +
> + if (!cfg->live) {
> + live_cfg = ad7173_find_live_config(st, cfg);
> + if (live_cfg) {
> + cfg->cfg_slot = live_cfg->cfg_slot;
> + } else {
> + ret = ad7173_load_config(st, cfg);
> + if (ret)
> + return ret;
> + cfg->live = true;
> + }
> + }
> +
> + if (st->config_usage_counter == U64_MAX)
> + ad7173_reset_usage_cnts(st);
> +
> + st->config_usage_counter++;
> + st->config_cnts[cfg->cfg_slot] = st->config_usage_counter;
> +
> + return 0;
> +}
> +
> +static int ad7173_set_channel(struct ad_sigma_delta *sd, unsigned int channel)
> +{
> + struct ad7173_state *st = ad_sigma_delta_to_ad7173(sd);
> + unsigned int val;
> + int ret;
> +
> + ret = ad7173_config_channel(st, channel);
> + if (ret)
> + return ret;
> +
> + val = AD7173_CH_ENABLE |
> + FIELD_PREP(AD7173_CH_SETUP_SEL_MASK, st->channels[channel].cfg.cfg_slot) |
> + st->channels[channel].ain;
> +
> + return ad_sd_write_reg(&st->sd, AD7173_REG_CH(channel), 2, val);
> +}
> +
> +static int ad7173_set_mode(struct ad_sigma_delta *sd,
> + enum ad_sigma_delta_mode mode)
> +{
> + struct ad7173_state *st = ad_sigma_delta_to_ad7173(sd);
> +
> + st->adc_mode &= ~AD7173_ADC_MODE_MODE_MASK;
> + st->adc_mode |= FIELD_PREP(AD7173_ADC_MODE_MODE_MASK, mode);
> +
> + return ad_sd_write_reg(&st->sd, AD7173_REG_ADC_MODE, 2, st->adc_mode);
> +}
> +
> +static int ad7173_append_status(struct ad_sigma_delta *sd, bool append)
> +{
> + struct ad7173_state *st = ad_sigma_delta_to_ad7173(sd);
> + unsigned int interface_mode = st->interface_mode;
> + int ret;
> +
> + interface_mode |= AD7173_INTERFACE_DATA_STAT_EN(append);
> + ret = ad_sd_write_reg(&st->sd, AD7173_REG_INTERFACE_MODE, 2, interface_mode);
> + if (ret)
> + return ret;
> +
> + st->interface_mode = interface_mode;
> +
> + return 0;
> +}
> +
> +static int ad7173_disable_all(struct ad_sigma_delta *sd)
> +{
> + struct ad7173_state *st = ad_sigma_delta_to_ad7173(sd);
> + int ret;
> + int i;
> +
> + for (i = 0; i < st->num_channels; i++) {
> + ret = ad_sd_write_reg(sd, AD7173_REG_CH(i), 2, 0);
> + if (ret < 0)
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static struct ad_sigma_delta_info ad7173_sigma_delta_info = {
> + .set_channel = ad7173_set_channel,
> + .append_status = ad7173_append_status,
> + .disable_all = ad7173_disable_all,
> + .set_mode = ad7173_set_mode,
> + .has_registers = true,
> + .addr_shift = 0,
> + .read_mask = BIT(6),
> + .status_ch_mask = GENMASK(3, 0),
> + .data_reg = AD7173_REG_DATA,
> + .irq_flags = IRQF_TRIGGER_FALLING,
> +};
> +
> +static int ad7173_setup(struct iio_dev *indio_dev)
> +{
> + struct ad7173_state *st = iio_priv(indio_dev);
> + u8 buf[AD7173_RESET_LENGTH];
> + unsigned int id;
> + int ret;
> +
> + /* reset the serial interface */
> + memset(buf, 0xff, AD7173_RESET_LENGTH);
> + ret = spi_write_then_read(st->sd.spi, buf, sizeof(buf), NULL, 0);
> + if (ret < 0)
> + return ret;
> +
> + /* datasheet recommends a delay of at least 500us after reset */
> + fsleep(500);
> +
> + ret = ad_sd_read_reg(&st->sd, AD7173_REG_ID, 2, &id);
> + if (ret)
> + return ret;
> +
> + id &= AD7173_ID_MASK;
> + if (id != st->info->id)
> + dev_warn(&st->sd.spi->dev,
> + "Unexpected device id: 0x%04X, expected: 0x%04X\n",
> + id, st->info->id);
> +
> + st->adc_mode |= AD7173_ADC_MODE_SING_CYC;
> + st->interface_mode = 0x0;
> +
> + st->config_usage_counter = 0;
> + st->config_cnts = devm_kcalloc(&st->sd.spi->dev, st->info->num_configs,
> + sizeof(u64), GFP_KERNEL);
> + if (!st->config_cnts)
> + return -ENOMEM;
> +
> + /* All channels are enabled by default after a reset */
> + return ad7173_disable_all(&st->sd);
> +}
> +
> +static unsigned int ad7173_get_ref_voltage_milli(struct ad7173_state *st,
> + u8 reference_select)
> +{
> + int vref;
> +
> + switch (reference_select) {
> + case AD7173_SETUP_REF_SEL_EXT_REF:
> + vref = regulator_get_voltage(st->regulators[0].consumer);
> + break;
> +
> + case AD7173_SETUP_REF_SEL_EXT_REF2:
> + vref = regulator_get_voltage(st->regulators[1].consumer);
> + break;
> +
> + case AD7173_SETUP_REF_SEL_INT_REF:
> + vref = AD7173_VOLTAGE_INT_REF_uV;
> + break;
> +
> + case AD7173_SETUP_REF_SEL_AVDD1_AVSS:
> + vref = regulator_get_voltage(st->regulators[2].consumer);
> + break;
> +
> + default:
> + return -EINVAL;
> + }
> +
> + if (vref < 0)
> + return vref;
> +
> + return vref / (MICRO / MILLI);
> +}
> +
> +static int ad7173_read_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + int *val, int *val2, long info)
> +{
> + struct ad7173_state *st = iio_priv(indio_dev);
> + struct ad7173_channel *ch = &st->channels[chan->address];
> + unsigned int reg;
> + u64 temp;
> + int ret;
> +
> + switch (info) {
> + case IIO_CHAN_INFO_RAW:
> + ret = ad_sigma_delta_single_conversion(indio_dev, chan, val);
> + if (ret < 0)
> + return ret;
> +
> + /* disable channel after single conversion */
> + ret = ad_sd_write_reg(&st->sd, AD7173_REG_CH(chan->address), 2, 0);
> + if (ret < 0)
> + return ret;
> +
> + return IIO_VAL_INT;
> + case IIO_CHAN_INFO_SCALE:
> + if (chan->type == IIO_TEMP) {
> + temp = AD7173_VOLTAGE_INT_REF_uV * MILLI;
> + temp /= AD7173_TEMP_SENSIIVITY_uV_per_C;
> + *val = temp;
> + *val2 = chan->scan_type.realbits;
> + } else {
> + *val = ad7173_get_ref_voltage_milli(st, ch->cfg.ref_sel);
> + *val2 = chan->scan_type.realbits - !!(ch->cfg.bipolar);
> + }
> + return IIO_VAL_FRACTIONAL_LOG2;
> + case IIO_CHAN_INFO_OFFSET:
> + if (chan->type == IIO_TEMP) {
> + /* 0 Kelvin -> raw sample */
> + temp = -ABSOLUTE_ZERO_MILLICELSIUS;
> + temp *= AD7173_TEMP_SENSIIVITY_uV_per_C;
> + temp <<= chan->scan_type.realbits;
> + temp = DIV_U64_ROUND_CLOSEST(temp,
> + AD7173_VOLTAGE_INT_REF_uV *
> + MILLI);
> + *val = -temp;
> + } else {
> + *val = -BIT(chan->scan_type.realbits - 1);
> + }
> + return IIO_VAL_INT;
> + case IIO_CHAN_INFO_SAMP_FREQ:
> + reg = st->channels[chan->address].cfg.odr;
> +
> + *val = st->info->sinc5_data_rates[reg] / MILLI;
> + *val2 = (st->info->sinc5_data_rates[reg] % MILLI) * (MICRO / MILLI);
> +
> + return IIO_VAL_INT_PLUS_MICRO;
> + default:
> + return -EINVAL;
> + }
> +}
> +
> +static int ad7173_write_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + int val, int val2, long info)
> +{
> + struct ad7173_state *st = iio_priv(indio_dev);
> + struct ad7173_channel_config *cfg;
> + unsigned int freq, i, reg;
> + int ret;
> +
> + ret = iio_device_claim_direct_mode(indio_dev);
> + if (ret)
> + return ret;
> +
> + switch (info) {
> + case IIO_CHAN_INFO_SAMP_FREQ:
> + freq = val * MILLI + val2 / MILLI;
> + for (i = 0; i < st->info->num_sinc5_data_rates - 1; i++)
> + if (freq >= st->info->sinc5_data_rates[i])
> + break;
> +
> + cfg = &st->channels[chan->address].cfg;
> + cfg->odr = i;
> +
> + if (!cfg->live)
> + break;
> +
> + ret = ad_sd_read_reg(&st->sd, AD7173_REG_FILTER(cfg->cfg_slot), 2, &reg);
> + if (ret)
> + break;
> + reg &= ~AD7173_FILTER_ODR0_MASK;
> + reg |= FIELD_PREP(AD7173_FILTER_ODR0_MASK, i);
> + ret = ad_sd_write_reg(&st->sd, AD7173_REG_FILTER(cfg->cfg_slot), 2, reg);
> + break;
> +
> + default:
> + ret = -EINVAL;
> + break;
> + }
> +
> + iio_device_release_direct_mode(indio_dev);
> + return ret;
> +}
> +
> +static int ad7173_update_scan_mode(struct iio_dev *indio_dev,
> + const unsigned long *scan_mask)
> +{
> + struct ad7173_state *st = iio_priv(indio_dev);
> + int i, ret;
> +
> + for (i = 0; i < indio_dev->num_channels; i++) {
> + if (test_bit(i, scan_mask))
> + ret = ad7173_set_channel(&st->sd, i);
> + else
> + ret = ad_sd_write_reg(&st->sd, AD7173_REG_CH(i), 2, 0);
> + if (ret < 0)
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int ad7173_debug_reg_access(struct iio_dev *indio_dev, unsigned int reg,
> + unsigned int writeval, unsigned int *readval)
> +{
> + struct ad7173_state *st = iio_priv(indio_dev);
> + u8 reg_size;
> +
> + if (reg == AD7173_REG_COMMS)
> + reg_size = 1;
> + else if (reg == AD7173_REG_CRC || reg == AD7173_REG_DATA ||
> + reg >= AD7173_REG_OFFSET(0))
> + reg_size = 3;
> + else
> + reg_size = 2;
> +
> + if (readval)
> + return ad_sd_read_reg(&st->sd, reg, reg_size, readval);
> +
> + return ad_sd_write_reg(&st->sd, reg, reg_size, writeval);
> +}
> +
> +static const struct iio_info ad7173_info = {
> + .read_raw = &ad7173_read_raw,
> + .write_raw = &ad7173_write_raw,
> + .debugfs_reg_access = &ad7173_debug_reg_access,
> + .validate_trigger = ad_sd_validate_trigger,
> + .update_scan_mode = ad7173_update_scan_mode,
> +};
> +
> +static const struct iio_chan_spec ad7173_channel_template = {
> + .type = IIO_VOLTAGE,
> + .indexed = 1,
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
> + BIT(IIO_CHAN_INFO_SCALE),
> + .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
> + .scan_type = {
> + .sign = 'u',
> + .realbits = 24,
> + .storagebits = 32,
> + .endianness = IIO_BE,
> + },
> +};
> +
> +static const struct iio_chan_spec ad7173_temp_iio_channel_template = {
> + .type = IIO_TEMP,
> + .indexed = 1,
> + .channel = AD7173_AIN_TEMP_POS,
> + .channel2 = AD7173_AIN_TEMP_NEG,
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
> + BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_OFFSET),
> + .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
> + .scan_type = {
> + .sign = 'u',
> + .realbits = 24,
> + .storagebits = 32,
> + .endianness = IIO_BE,
> + },
> +};
> +
> +static void ad7173_disable_regulators(void *data)
> +{
> + struct ad7173_state *st = data;
> +
> + regulator_bulk_disable(ARRAY_SIZE(st->regulators), st->regulators);
> +}
> +
> +static int ad7173_fw_parse_channel_config(struct iio_dev *indio_dev)
> +{
> + struct ad7173_channel *chans_st_arr, *chan_st_priv;
> + struct ad7173_state *st = iio_priv(indio_dev);
> + struct device *dev = indio_dev->dev.parent;
> + struct iio_chan_spec *chan_arr, *chan;
> + struct fwnode_handle *child;
> + unsigned int ain[2], chan_index = 0;
> + unsigned int num_channels;
> + int ref_sel;
> + int ret;
> +
> + st->regulators[0].supply = ad7173_ref_sel_str[AD7173_SETUP_REF_SEL_EXT_REF];
> + st->regulators[1].supply = ad7173_ref_sel_str[AD7173_SETUP_REF_SEL_EXT_REF2];
> + st->regulators[2].supply = ad7173_ref_sel_str[AD7173_SETUP_REF_SEL_AVDD1_AVSS];
> +
> + /*
> + * If a regulator is not available, it will be set to a dummy regulator.
> + * Each channel reference is checked with regulator_get_voltage() before
> + * setting attributes so if any channel uses a dummy supply the driver
> + * probe will fail.
> + */
> + ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(st->regulators),
> + st->regulators);
> + if (ret)
> + return dev_err_probe(dev, ret, "Failed to get regulators\n");
> +
> + ret = regulator_bulk_enable(ARRAY_SIZE(st->regulators), st->regulators);
> + if (ret)
> + return dev_err_probe(dev, ret, "Failed to enable regulators\n");
> +
> + ret = devm_add_action_or_reset(dev, ad7173_disable_regulators, st);
> + if (ret)
> + return dev_err_probe(dev, ret,
> + "Failed to add regulators disable action\n");
> +
> + num_channels = device_get_child_node_count(dev);
> +
> + if (st->info->has_temp)
> + num_channels++;
> +
> + if (num_channels == 0)
> + return dev_err_probe(dev, -EINVAL, "No channels specified\n");
> + st->num_channels = num_channels;
> +
> + chan_arr = devm_kcalloc(dev, sizeof(*chan_arr), num_channels, GFP_KERNEL);
> + if (!chan_arr)
> + return -ENOMEM;
> +
> + chans_st_arr = devm_kcalloc(dev, num_channels, sizeof(*chans_st_arr),
> + GFP_KERNEL);
> + if (!chans_st_arr)
> + return -ENOMEM;
> +
> + indio_dev->channels = chan_arr;
> + indio_dev->num_channels = num_channels;
> + st->channels = chans_st_arr;
> +
> + if (st->info->has_temp) {
> + chan_arr[chan_index] = ad7173_temp_iio_channel_template;
> + chan_st_priv = &chans_st_arr[chan_index];
> + chan_st_priv->ain =
> + AD7173_CH_ADDRESS(chan_arr[chan_index].channel, chan_arr[chan_index].channel2);
> + chan_st_priv->cfg.bipolar = false;
> + chan_st_priv->cfg.input_buf = true;
> + chan_st_priv->cfg.ref_sel = AD7173_SETUP_REF_SEL_INT_REF;
> + st->adc_mode |= AD7173_ADC_MODE_REF_EN;
> +
> + chan_index++;
> + }
> +
> + device_for_each_child_node(dev, child) {
> + chan = &chan_arr[chan_index];
> + chan_st_priv = &chans_st_arr[chan_index];
> + ret = fwnode_property_read_u32_array(child, "diff-channels",
> + ain, ARRAY_SIZE(ain));
> + if (ret) {
> + fwnode_handle_put(child);
> + return ret;
> + }
> +
> + if (ain[0] >= st->info->num_inputs ||
> + ain[1] >= st->info->num_inputs) {
> + fwnode_handle_put(child);
> + return dev_err_probe(dev, -EINVAL,
> + "Input pin number out of range for pair (%d %d).\n",
> + ain[0], ain[1]);
> + }
> +
> + ret = fwnode_property_match_property_string(child,
> + "adi,reference-select",
> + ad7173_ref_sel_str,
> + ARRAY_SIZE(ad7173_ref_sel_str));
> + if (ret < 0)
> + ref_sel = AD7173_SETUP_REF_SEL_INT_REF;
> + else
> + ref_sel = ret;
> +
> + if (ref_sel == AD7173_SETUP_REF_SEL_EXT_REF2 &&
> + st->info->id != AD7173_ID) {
> + fwnode_handle_put(child);
> + return dev_err_probe(dev, -EINVAL, "External reference 2 is only available on ad7173-8\n");
> + }
> +
> + ret = ad7173_get_ref_voltage_milli(st, ref_sel);
> + if (ret < 0) {
> + fwnode_handle_put(child);
> + return dev_err_probe(dev, ret,
> + "Cannot use reference %u\n", ref_sel);
> + }
> + if (ref_sel == AD7173_SETUP_REF_SEL_INT_REF)
> + st->adc_mode |= AD7173_ADC_MODE_REF_EN;
> + chan_st_priv->cfg.ref_sel = ref_sel;
> +
> + *chan = ad7173_channel_template;
> + chan->address = chan_index;
> + chan->scan_index = chan_index;
> + chan->channel = ain[0];
> + chan->channel2 = ain[1];
> + chan->differential = true;
> +
> + chan_st_priv->ain = AD7173_CH_ADDRESS(ain[0], ain[1]);
> + chan_st_priv->chan_reg = chan_index;
> + chan_st_priv->cfg.input_buf = true;
> + chan_st_priv->cfg.odr = 0;
> +
> + chan_st_priv->cfg.bipolar = fwnode_property_read_bool(child, "bipolar");
> + if (chan_st_priv->cfg.bipolar)
> + chan->info_mask_separate |= BIT(IIO_CHAN_INFO_OFFSET);
> +
> + chan_index++;
> + }
> +
> + return 0;
> +}
> +
> +static int ad7173_probe(struct spi_device *spi)
> +{
> + struct device *dev = &spi->dev;
> + struct ad7173_state *st;
> + struct iio_dev *indio_dev;
> + int ret;
> +
> + indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
> + if (!indio_dev)
> + return -ENOMEM;
> +
> + st = iio_priv(indio_dev);
> + st->info = spi_get_device_match_data(spi);
> + if (!st->info)
> + return -ENODEV;
> +
> + ida_init(&st->cfg_slots_status);
> + ret = devm_add_action_or_reset(dev, ad7173_ida_destroy, st);
> + if (ret)
> + return ret;
> +
> + indio_dev->name = st->info->name;
> + indio_dev->modes = INDIO_DIRECT_MODE;
> + indio_dev->info = &ad7173_info;
> +
> + spi->mode = SPI_MODE_3;
> +
> + ad7173_sigma_delta_info.num_slots = st->info->num_configs;
> + ret = ad_sd_init(&st->sd, indio_dev, spi, &ad7173_sigma_delta_info);
> + if (ret)
> + return ret;
> +
> + ret = ad7173_fw_parse_channel_config(indio_dev);
> + if (ret)
> + return ret;
> +
> + ret = devm_ad_sd_setup_buffer_and_trigger(dev, indio_dev);
> + if (ret)
> + return ret;
> +
> + ret = ad7173_setup(indio_dev);
> + if (ret)
> + return ret;
> +
> + ret = devm_iio_device_register(dev, indio_dev);
> + if (ret)
> + return ret;
> +
> + if (IS_ENABLED(CONFIG_GPIOLIB))
> + return ad7173_gpio_init(st);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id ad7173_of_match[] = {
> + { .compatible = "adi,ad7172-2",
> + .data = &ad7173_device_info[ID_AD7172_2]},
> + { .compatible = "adi,ad7173-8",
> + .data = &ad7173_device_info[ID_AD7173_8]},
> + { .compatible = "adi,ad7175-2",
> + .data = &ad7173_device_info[ID_AD7175_2]},
> + { .compatible = "adi,ad7176-2",
> + .data = &ad7173_device_info[ID_AD7176_2]},
> + { }
> +};
> +MODULE_DEVICE_TABLE(of, ad7173_of_match);
> +
> +static const struct spi_device_id ad7173_id_table[] = {
> + { "ad7172-2", (kernel_ulong_t)&ad7173_device_info[ID_AD7172_2]},
> + { "ad7173-8", (kernel_ulong_t)&ad7173_device_info[ID_AD7173_8]},
> + { "ad7175-2", (kernel_ulong_t)&ad7173_device_info[ID_AD7175_2]},
> + { "ad7176-2", (kernel_ulong_t)&ad7173_device_info[ID_AD7176_2]},
> + { }
> +};
> +MODULE_DEVICE_TABLE(spi, ad7173_id_table);
> +
> +static struct spi_driver ad7173_driver = {
> + .driver = {
> + .name = "ad7173",
> + .of_match_table = ad7173_of_match,
> + },
> + .probe = ad7173_probe,
> + .id_table = ad7173_id_table,
> +};
> +module_spi_driver(ad7173_driver);
> +
> +MODULE_AUTHOR("Lars-Peter Clausen <lars@metafo.de>");
> +MODULE_AUTHOR("Dumitru Ceclan <dumitru.ceclan@analog.com>");
> +MODULE_DESCRIPTION("Analog Devices AD7172/AD7173/AD7175/AD7176 ADC driver");
> +MODULE_LICENSE("GPL");