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

Dumitru Ceclan
2023-12-20T10:48:25Z

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>
---

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");
--
2.42.0