diff options
| -rw-r--r-- | MAINTAINERS | 1 | ||||
| -rw-r--r-- | drivers/iio/adc/Kconfig | 11 | ||||
| -rw-r--r-- | drivers/iio/adc/Makefile | 1 | ||||
| -rw-r--r-- | drivers/iio/adc/ad4695.c | 734 |
4 files changed, 747 insertions, 0 deletions
diff --git a/MAINTAINERS b/MAINTAINERS index d38d73c0ee42..75ad7f1ecbb9 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -1231,6 +1231,7 @@ L: linux-iio@vger.kernel.org S: Supported W: https://ez.analog.com/linux-software-drivers F: Documentation/devicetree/bindings/iio/adc/adi,ad4695.yaml +F: drivers/iio/adc/ad4695.c F: include/dt-bindings/iio/adi,ad4695.h ANALOG DEVICES INC AD7091R DRIVER diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig index f60fe85a30d5..81464bb209ea 100644 --- a/drivers/iio/adc/Kconfig +++ b/drivers/iio/adc/Kconfig @@ -36,6 +36,17 @@ config AD4130 To compile this driver as a module, choose M here: the module will be called ad4130. +config AD4695 + tristate "Analog Device AD4695 ADC Driver" + depends on SPI + select REGMAP_SPI + help + Say yes here to build support for Analog Devices AD4695 and similar + analog to digital converters (ADC). + + To compile this driver as a module, choose M here: the module will be + called ad4695. + config AD7091R tristate diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile index d370e066544e..b1bda281c10f 100644 --- a/drivers/iio/adc/Makefile +++ b/drivers/iio/adc/Makefile @@ -7,6 +7,7 @@ obj-$(CONFIG_AB8500_GPADC) += ab8500-gpadc.o obj-$(CONFIG_AD_SIGMA_DELTA) += ad_sigma_delta.o obj-$(CONFIG_AD4130) += ad4130.o +obj-$(CONFIG_AD4695) += ad4695.o obj-$(CONFIG_AD7091R) += ad7091r-base.o obj-$(CONFIG_AD7091R5) += ad7091r5.o obj-$(CONFIG_AD7091R8) += ad7091r8.o diff --git a/drivers/iio/adc/ad4695.c b/drivers/iio/adc/ad4695.c new file mode 100644 index 000000000000..007ecb951bc3 --- /dev/null +++ b/drivers/iio/adc/ad4695.c @@ -0,0 +1,734 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * SPI ADC driver for Analog Devices Inc. AD4695 and similar chips + * + * https://www.analog.com/en/products/ad4695.html + * https://www.analog.com/en/products/ad4696.html + * https://www.analog.com/en/products/ad4697.html + * https://www.analog.com/en/products/ad4698.html + * + * Copyright 2024 Analog Devices Inc. + * Copyright 2024 BayLibre, SAS + */ + +#include <linux/bitfield.h> +#include <linux/bits.h> +#include <linux/compiler.h> +#include <linux/delay.h> +#include <linux/device.h> +#include <linux/err.h> +#include <linux/gpio/consumer.h> +#include <linux/iio/iio.h> +#include <linux/property.h> +#include <linux/regmap.h> +#include <linux/regulator/consumer.h> +#include <linux/spi/spi.h> +#include <linux/units.h> + +#include <dt-bindings/iio/adi,ad4695.h> + +/* AD4695 registers */ +#define AD4695_REG_SPI_CONFIG_A 0x0000 +#define AD4695_REG_SPI_CONFIG_A_SW_RST (BIT(7) | BIT(0)) +#define AD4695_REG_SPI_CONFIG_B 0x0001 +#define AD4695_REG_SPI_CONFIG_B_INST_MODE BIT(7) +#define AD4695_REG_DEVICE_TYPE 0x0003 +#define AD4695_REG_SCRATCH_PAD 0x000A +#define AD4695_REG_VENDOR_L 0x000C +#define AD4695_REG_VENDOR_H 0x000D +#define AD4695_REG_LOOP_MODE 0x000E +#define AD4695_REG_SPI_CONFIG_C 0x0010 +#define AD4695_REG_SPI_CONFIG_C_MB_STRICT BIT(7) +#define AD4695_REG_SPI_STATUS 0x0011 +#define AD4695_REG_STATUS 0x0014 +#define AD4695_REG_ALERT_STATUS1 0x0015 +#define AD4695_REG_ALERT_STATUS2 0x0016 +#define AD4695_REG_CLAMP_STATUS 0x001A +#define AD4695_REG_SETUP 0x0020 +#define AD4695_REG_SETUP_LDO_EN BIT(4) +#define AD4695_REG_SETUP_SPI_MODE BIT(2) +#define AD4695_REG_SETUP_SPI_CYC_CTRL BIT(1) +#define AD4695_REG_REF_CTRL 0x0021 +#define AD4695_REG_REF_CTRL_OV_MODE BIT(7) +#define AD4695_REG_REF_CTRL_VREF_SET GENMASK(4, 2) +#define AD4695_REG_REF_CTRL_REFHIZ_EN BIT(1) +#define AD4695_REG_REF_CTRL_REFBUF_EN BIT(0) +#define AD4695_REG_SEQ_CTRL 0x0022 +#define AD4695_REG_SEQ_CTRL_STD_SEQ_EN BIT(7) +#define AD4695_REG_SEQ_CTRL_NUM_SLOTS_AS GENMASK(6, 0) +#define AD4695_REG_AC_CTRL 0x0023 +#define AD4695_REG_STD_SEQ_CONFIG 0x0024 +#define AD4695_REG_GPIO_CTRL 0x0026 +#define AD4695_REG_GP_MODE 0x0027 +#define AD4695_REG_TEMP_CTRL 0x0029 +#define AD4695_REG_CONFIG_IN(n) (0x0030 | (n)) +#define AD4695_REG_CONFIG_IN_MODE BIT(6) +#define AD4695_REG_CONFIG_IN_PAIR GENMASK(5, 4) +#define AD4695_REG_CONFIG_IN_AINHIGHZ_EN BIT(3) +#define AD4695_REG_UPPER_IN(n) (0x0040 | (2 * (n))) +#define AD4695_REG_LOWER_IN(n) (0x0060 | (2 * (n))) +#define AD4695_REG_HYST_IN(n) (0x0080 | (2 * (n))) +#define AD4695_REG_OFFSET_IN(n) (0x00A0 | (2 * (n))) +#define AD4695_REG_GAIN_IN(n) (0x00C0 | (2 * (n))) +#define AD4695_REG_AS_SLOT(n) (0x0100 | (n)) +#define AD4695_REG_AS_SLOT_INX GENMASK(3, 0) +#define AD4695_MAX_REG 0x017F + +/* Conversion mode commands */ +#define AD4695_CMD_EXIT_CNV_MODE 0x0A +#define AD4695_CMD_TEMP_CHAN 0x0F +#define AD4695_CMD_VOLTAGE_CHAN(n) (0x10 | (n)) + +/* timing specs */ +#define AD4695_T_CONVERT_NS 415 +#define AD4695_T_WAKEUP_HW_MS 3 +#define AD4695_T_WAKEUP_SW_MS 3 +#define AD4695_T_REFBUF_MS 100 +#define AD4695_REG_ACCESS_SCLK_HZ (10 * MEGA) + +#define AD4695_MAX_CHANNELS 16 + +enum ad4695_in_pair { + AD4695_IN_PAIR_REFGND, + AD4695_IN_PAIR_COM, + AD4695_IN_PAIR_EVEN_ODD, +}; + +struct ad4695_chip_info { + const char *name; + int max_sample_rate; + u8 num_voltage_inputs; +}; + +struct ad4695_channel_config { + unsigned int channel; + bool highz_en; + bool bipolar; + enum ad4695_in_pair pin_pairing; + unsigned int common_mode_mv; +}; + +struct ad4695_state { + struct spi_device *spi; + struct regmap *regmap; + struct gpio_desc *reset_gpio; + struct iio_chan_spec iio_chan[AD4695_MAX_CHANNELS + 1]; + struct ad4695_channel_config channels_cfg[AD4695_MAX_CHANNELS]; + const struct ad4695_chip_info *chip_info; + /* Reference voltage. */ + unsigned int vref_mv; + /* Common mode input pin voltage. */ + unsigned int com_mv; + /* Raw conversion data received. */ + u16 raw_data __aligned(IIO_DMA_MINALIGN); + /* Commands to send for single conversion. */ + u16 cnv_cmd; + u8 cnv_cmd2; +}; + +static const struct regmap_range ad4695_regmap_rd_ranges[] = { + regmap_reg_range(AD4695_REG_SPI_CONFIG_A, AD4695_REG_SPI_CONFIG_B), + regmap_reg_range(AD4695_REG_DEVICE_TYPE, AD4695_REG_DEVICE_TYPE), + regmap_reg_range(AD4695_REG_SCRATCH_PAD, AD4695_REG_SCRATCH_PAD), + regmap_reg_range(AD4695_REG_VENDOR_L, AD4695_REG_LOOP_MODE), + regmap_reg_range(AD4695_REG_SPI_CONFIG_C, AD4695_REG_SPI_STATUS), + regmap_reg_range(AD4695_REG_STATUS, AD4695_REG_ALERT_STATUS2), + regmap_reg_range(AD4695_REG_CLAMP_STATUS, AD4695_REG_CLAMP_STATUS), + regmap_reg_range(AD4695_REG_SETUP, AD4695_REG_TEMP_CTRL), + regmap_reg_range(AD4695_REG_CONFIG_IN(0), AD4695_MAX_REG), +}; + +static const struct regmap_access_table ad4695_regmap_rd_table = { + .yes_ranges = ad4695_regmap_rd_ranges, + .n_yes_ranges = ARRAY_SIZE(ad4695_regmap_rd_ranges), +}; + +static const struct regmap_range ad4695_regmap_wr_ranges[] = { + regmap_reg_range(AD4695_REG_SPI_CONFIG_A, AD4695_REG_SPI_CONFIG_B), + regmap_reg_range(AD4695_REG_SCRATCH_PAD, AD4695_REG_SCRATCH_PAD), + regmap_reg_range(AD4695_REG_LOOP_MODE, AD4695_REG_LOOP_MODE), + regmap_reg_range(AD4695_REG_SPI_CONFIG_C, AD4695_REG_SPI_STATUS), + regmap_reg_range(AD4695_REG_SETUP, AD4695_REG_TEMP_CTRL), + regmap_reg_range(AD4695_REG_CONFIG_IN(0), AD4695_MAX_REG), +}; + +static const struct regmap_access_table ad4695_regmap_wr_table = { + .yes_ranges = ad4695_regmap_wr_ranges, + .n_yes_ranges = ARRAY_SIZE(ad4695_regmap_wr_ranges), +}; + +static const struct regmap_config ad4695_regmap_config = { + .name = "ad4695", + .reg_bits = 16, + .val_bits = 8, + .max_register = AD4695_MAX_REG, + .rd_table = &ad4695_regmap_rd_table, + .wr_table = &ad4695_regmap_wr_table, + .can_multi_write = true, +}; + +static const struct iio_chan_spec ad4695_channel_template = { + .type = IIO_VOLTAGE, + .indexed = 1, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE) | + BIT(IIO_CHAN_INFO_OFFSET), + .scan_type = { + .sign = 'u', + .realbits = 16, + .storagebits = 16, + }, +}; + +static const struct iio_chan_spec ad4695_temp_channel_template = { + .address = AD4695_CMD_TEMP_CHAN, + .type = IIO_TEMP, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE) | + BIT(IIO_CHAN_INFO_OFFSET), + .scan_type = { + .sign = 's', + .realbits = 16, + .storagebits = 16, + }, +}; + +static const char * const ad4695_power_supplies[] = { + "avdd", "vio" +}; + +static const struct ad4695_chip_info ad4695_chip_info = { + .name = "ad4695", + .max_sample_rate = 500 * KILO, + .num_voltage_inputs = 16, +}; + +static const struct ad4695_chip_info ad4696_chip_info = { + .name = "ad4696", + .max_sample_rate = 1 * MEGA, + .num_voltage_inputs = 16, +}; + +static const struct ad4695_chip_info ad4697_chip_info = { + .name = "ad4697", + .max_sample_rate = 500 * KILO, + .num_voltage_inputs = 8, +}; + +static const struct ad4695_chip_info ad4698_chip_info = { + .name = "ad4698", + .max_sample_rate = 1 * MEGA, + .num_voltage_inputs = 8, +}; + +/** + * ad4695_set_single_cycle_mode - Set the device in single cycle mode + * @st: The AD4695 state + * @channel: The first channel to read + * + * As per the datasheet, to enable single cycle mode, we need to set + * STD_SEQ_EN=0, NUM_SLOTS_AS=0 and CYC_CTRL=1 (Table 15). Setting SPI_MODE=1 + * triggers the first conversion using the channel in AS_SLOT0. + * + * Context: can sleep, must be called with iio_device_claim_direct held + * Return: 0 on success, a negative error code on failure + */ +static int ad4695_set_single_cycle_mode(struct ad4695_state *st, + unsigned int channel) +{ + int ret; + + ret = regmap_clear_bits(st->regmap, AD4695_REG_SEQ_CTRL, + AD4695_REG_SEQ_CTRL_STD_SEQ_EN | + AD4695_REG_SEQ_CTRL_NUM_SLOTS_AS); + if (ret) + return ret; + + ret = regmap_write(st->regmap, AD4695_REG_AS_SLOT(0), + FIELD_PREP(AD4695_REG_AS_SLOT_INX, channel)); + if (ret) + return ret; + + return regmap_set_bits(st->regmap, AD4695_REG_SETUP, + AD4695_REG_SETUP_SPI_MODE | + AD4695_REG_SETUP_SPI_CYC_CTRL); +} + +static int ad4695_set_ref_voltage(struct ad4695_state *st, int vref_mv) +{ + u8 val; + + if (vref_mv >= 2400 && vref_mv <= 2750) + val = 0; + else if (vref_mv > 2750 && vref_mv <= 3250) + val = 1; + else if (vref_mv > 3250 && vref_mv <= 3750) + val = 2; + else if (vref_mv > 3750 && vref_mv <= 4500) + val = 3; + else if (vref_mv > 4500 && vref_mv <= 5100) + val = 4; + else + return -EINVAL; + + return regmap_update_bits(st->regmap, AD4695_REG_REF_CTRL, + AD4695_REG_REF_CTRL_VREF_SET, + FIELD_PREP(AD4695_REG_REF_CTRL_VREF_SET, val)); +} + +static int ad4695_write_chn_cfg(struct ad4695_state *st, + struct ad4695_channel_config *cfg) +{ + u32 mask, val; + + mask = AD4695_REG_CONFIG_IN_MODE; + val = FIELD_PREP(AD4695_REG_CONFIG_IN_MODE, cfg->bipolar ? 1 : 0); + + mask |= AD4695_REG_CONFIG_IN_PAIR; + val |= FIELD_PREP(AD4695_REG_CONFIG_IN_PAIR, cfg->pin_pairing); + + mask |= AD4695_REG_CONFIG_IN_AINHIGHZ_EN; + val |= FIELD_PREP(AD4695_REG_CONFIG_IN_AINHIGHZ_EN, + cfg->highz_en ? 1 : 0); + + return regmap_update_bits(st->regmap, + AD4695_REG_CONFIG_IN(cfg->channel), + mask, val); +} + +/** + * ad4695_read_one_sample - Read a single sample using single-cycle mode + * @st: The AD4695 state + * @address: The address of the channel to read + * + * Upon successful return, the sample will be stored in `st->raw_data`. + * + * Context: can sleep, must be called with iio_device_claim_direct held + * Return: 0 on success, a negative error code on failure + */ +static int ad4695_read_one_sample(struct ad4695_state *st, unsigned int address) +{ + struct spi_transfer xfer[2] = { }; + int ret, i = 0; + + ret = ad4695_set_single_cycle_mode(st, address); + if (ret) + return ret; + + /* + * Setting the first channel to the temperature channel isn't supported + * in single-cycle mode, so we have to do an extra xfer to read the + * temperature. + */ + if (address == AD4695_CMD_TEMP_CHAN) { + /* We aren't reading, so we can make this a short xfer. */ + st->cnv_cmd2 = AD4695_CMD_TEMP_CHAN << 3; + xfer[0].tx_buf = &st->cnv_cmd2; + xfer[0].len = 1; + xfer[0].cs_change = 1; + xfer[0].cs_change_delay.value = AD4695_T_CONVERT_NS; + xfer[0].cs_change_delay.unit = SPI_DELAY_UNIT_NSECS; + + i = 1; + } + + /* Then read the result and exit conversion mode. */ + st->cnv_cmd = AD4695_CMD_EXIT_CNV_MODE << 11; + xfer[i].bits_per_word = 16; + xfer[i].tx_buf = &st->cnv_cmd; + xfer[i].rx_buf = &st->raw_data; + xfer[i].len = 2; + + return spi_sync_transfer(st->spi, xfer, i + 1); +} + +static int ad4695_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + struct ad4695_state *st = iio_priv(indio_dev); + struct ad4695_channel_config *cfg = &st->channels_cfg[chan->scan_index]; + u8 realbits = chan->scan_type.realbits; + int ret; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + iio_device_claim_direct_scoped(return -EBUSY, indio_dev) { + ret = ad4695_read_one_sample(st, chan->address); + if (ret) + return ret; + + if (chan->scan_type.sign == 's') + *val = sign_extend32(st->raw_data, realbits - 1); + else + *val = st->raw_data; + + return IIO_VAL_INT; + } + unreachable(); + case IIO_CHAN_INFO_SCALE: + switch (chan->type) { + case IIO_VOLTAGE: + *val = st->vref_mv; + *val2 = chan->scan_type.realbits; + return IIO_VAL_FRACTIONAL_LOG2; + case IIO_TEMP: + /* T_scale (°C) = raw * V_REF (mV) / (-1.8 mV/°C * 2^16) */ + *val = st->vref_mv * -556; + *val2 = 16; + return IIO_VAL_FRACTIONAL_LOG2; + default: + return -EINVAL; + } + case IIO_CHAN_INFO_OFFSET: + switch (chan->type) { + case IIO_VOLTAGE: + if (cfg->pin_pairing == AD4695_IN_PAIR_COM) + *val = st->com_mv * (1 << realbits) / st->vref_mv; + else if (cfg->pin_pairing == AD4695_IN_PAIR_EVEN_ODD) + *val = cfg->common_mode_mv * (1 << realbits) / st->vref_mv; + else + *val = 0; + + return IIO_VAL_INT; + case IIO_TEMP: + /* T_offset (°C) = -725 mV / (-1.8 mV/°C) */ + /* T_offset (raw) = T_offset (°C) * (-1.8 mV/°C) * 2^16 / V_REF (mV) */ + *val = -47513600; + *val2 = st->vref_mv; + return IIO_VAL_FRACTIONAL; + default: + return -EINVAL; + } + default: + return -EINVAL; + } +} + +static int ad4695_debugfs_reg_access(struct iio_dev *indio_dev, + unsigned int reg, + unsigned int writeval, + unsigned int *readval) +{ + struct ad4695_state *st = iio_priv(indio_dev); + + iio_device_claim_direct_scoped(return -EBUSY, indio_dev) { + if (readval) + return regmap_read(st->regmap, reg, readval); + + return regmap_write(st->regmap, reg, writeval); + } + + unreachable(); +} + +static const struct iio_info ad4695_info = { + .read_raw = &ad4695_read_raw, + .debugfs_reg_access = &ad4695_debugfs_reg_access, +}; + +static int ad4695_parse_channel_cfg(struct ad4695_state *st) +{ + struct device *dev = &st->spi->dev; + struct ad4695_channel_config *chan_cfg; + struct iio_chan_spec *iio_chan; + int ret, i; + + /* populate defaults */ + for (i = 0; i < st->chip_info->num_voltage_inputs; i++) { + chan_cfg = &st->channels_cfg[i]; + iio_chan = &st->iio_chan[i]; + + chan_cfg->highz_en = true; + chan_cfg->channel = i; + + *iio_chan = ad4695_channel_template; + iio_chan->channel = i; + iio_chan->scan_index = i; + iio_chan->address = AD4695_CMD_VOLTAGE_CHAN(i); + } + + /* modify based on firmware description */ + device_for_each_child_node_scoped(dev, child) { + u32 reg, val; + + ret = fwnode_property_read_u32(child, "reg", ®); + if (ret) + return dev_err_probe(dev, ret, + "failed to read reg property (%s)\n", + fwnode_get_name(child)); + + if (reg >= st->chip_info->num_voltage_inputs) + return dev_err_probe(dev, -EINVAL, + "reg out of range (%s)\n", + fwnode_get_name(child)); + + iio_chan = &st->iio_chan[reg]; + chan_cfg = &st->channels_cfg[reg]; + + chan_cfg->highz_en = + !fwnode_property_read_bool(child, "adi,no-high-z"); + chan_cfg->bipolar = fwnode_property_read_bool(child, "bipolar"); + + ret = fwnode_property_read_u32(child, "common-mode-channel", + &val); + if (ret && ret != -EINVAL) + return dev_err_probe(dev, ret, + "failed to read common-mode-channel (%s)\n", + fwnode_get_name(child)); + + if (ret == -EINVAL || val == AD4695_COMMON_MODE_REFGND) + chan_cfg->pin_pairing = AD4695_IN_PAIR_REFGND; + else if (val == AD4695_COMMON_MODE_COM) + chan_cfg->pin_pairing = AD4695_IN_PAIR_COM; + else + chan_cfg->pin_pairing = AD4695_IN_PAIR_EVEN_ODD; + + if (chan_cfg->pin_pairing == AD4695_IN_PAIR_EVEN_ODD && + val % 2 == 0) + return dev_err_probe(dev, -EINVAL, + "common-mode-channel must be odd number (%s)\n", + fwnode_get_name(child)); + + if (chan_cfg->pin_pairing == AD4695_IN_PAIR_EVEN_ODD && + val != reg + 1) + return dev_err_probe(dev, -EINVAL, + "common-mode-channel must be next consecutive channel (%s)\n", + fwnode_get_name(child)); + + if (chan_cfg->pin_pairing == AD4695_IN_PAIR_EVEN_ODD) { + char name[5]; + + snprintf(name, sizeof(name), "in%d", reg + 1); + + ret = devm_regulator_get_enable_read_voltage(dev, name); + if (ret < 0) + return dev_err_probe(dev, ret, + "failed to get %s voltage (%s)\n", + name, fwnode_get_name(child)); + + chan_cfg->common_mode_mv = ret / 1000; + } + + if (chan_cfg->bipolar && + chan_cfg->pin_pairing == AD4695_IN_PAIR_REFGND) + return dev_err_probe(dev, -EINVAL, + "bipolar mode is not available for inputs paired with REFGND (%s).\n", + fwnode_get_name(child)); + + if (chan_cfg->bipolar) + iio_chan->scan_type.sign = 's'; + + ret = ad4695_write_chn_cfg(st, chan_cfg); + if (ret) + return ret; + } + + /* Temperature channel must be next scan index after voltage channels. */ + st->iio_chan[i] = ad4695_temp_channel_template; + st->iio_chan[i].scan_index = i; + + return 0; +} + +static int ad4695_probe(struct spi_device *spi) +{ + struct device *dev = &spi->dev; + struct ad4695_state *st; + struct iio_dev *indio_dev; + struct gpio_desc *cnv_gpio; + bool use_internal_ldo_supply; + bool use_internal_ref_buffer; + int ret; + + cnv_gpio = devm_gpiod_get_optional(dev, "cnv", GPIOD_OUT_LOW); + if (IS_ERR(cnv_gpio)) + return dev_err_probe(dev, PTR_ERR(cnv_gpio), + "Failed to get CNV GPIO\n"); + + /* Driver currently requires CNV pin to be connected to SPI CS */ + if (cnv_gpio) + return dev_err_probe(dev, -ENODEV, + "CNV GPIO is not supported\n"); + + indio_dev = devm_iio_device_alloc(dev, sizeof(*st)); + if (!indio_dev) + return -ENOMEM; + + st = iio_priv(indio_dev); + st->spi = spi; + + st->chip_info = spi_get_device_match_data(spi); + if (!st->chip_info) + return -EINVAL; + + /* Registers cannot be read at the max allowable speed */ + spi->max_speed_hz = AD4695_REG_ACCESS_SCLK_HZ; + + st->regmap = devm_regmap_init_spi(spi, &ad4695_regmap_config); + if (IS_ERR(st->regmap)) + return dev_err_probe(dev, PTR_ERR(st->regmap), + "Failed to initialize regmap\n"); + + ret = devm_regulator_bulk_get_enable(dev, + ARRAY_SIZE(ad4695_power_supplies), + ad4695_power_supplies); + if (ret) + return dev_err_probe(dev, ret, + "Failed to enable power supplies\n"); + + /* If LDO_IN supply is present, then we are using internal LDO. */ + ret = devm_regulator_get_enable_optional(dev, "ldo-in"); + if (ret < 0 && ret != -ENODEV) + return dev_err_probe(dev, ret, + "Failed to enable LDO_IN supply\n"); + + use_internal_ldo_supply = ret == 0; + + if (!use_internal_ldo_supply) { + /* Otherwise we need an external VDD supply. */ + ret = devm_regulator_get_enable(dev, "vdd"); + if (ret < 0) + return dev_err_probe(dev, ret, + "Failed to enable VDD supply\n"); + } + + /* If REFIN supply is given, then we are using internal buffer */ + ret = devm_regulator_get_enable_read_voltage(dev, "refin"); + if (ret < 0 && ret != -ENODEV) + return dev_err_probe(dev, ret, "Failed to get REFIN voltage\n"); + + if (ret != -ENODEV) { + st->vref_mv = ret / 1000; + use_internal_ref_buffer = true; + } else { + /* Otherwise, we need an external reference. */ + ret = devm_regulator_get_enable_read_voltage(dev, "ref"); + if (ret < 0) + return dev_err_probe(dev, ret, + "Failed to get REF voltage\n"); + + st->vref_mv = ret / 1000; + use_internal_ref_buffer = false; + } + + ret = devm_regulator_get_enable_read_voltage(dev, "com"); + if (ret < 0 && ret != -ENODEV) + return dev_err_probe(dev, ret, "Failed to get COM voltage\n"); + + st->com_mv = ret == -ENODEV ? 0 : ret / 1000; + + /* + * Reset the device using hardware reset if available or fall back to + * software reset. + */ + + st->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH); + if (IS_ERR(st->reset_gpio)) + return PTR_ERR(st->reset_gpio); + + if (st->reset_gpio) { + gpiod_set_value(st->reset_gpio, 0); + msleep(AD4695_T_WAKEUP_HW_MS); + } else { + ret = regmap_write(st->regmap, AD4695_REG_SPI_CONFIG_A, + AD4695_REG_SPI_CONFIG_A_SW_RST); + if (ret) + return ret; + + msleep(AD4695_T_WAKEUP_SW_MS); + } + + /* Needed for debugfs since it only access registers 1 byte at a time. */ + ret = regmap_set_bits(st->regmap, AD4695_REG_SPI_CONFIG_C, + AD4695_REG_SPI_CONFIG_C_MB_STRICT); + if (ret) + return ret; + + /* Disable internal LDO if it isn't needed. */ + ret = regmap_update_bits(st->regmap, AD4695_REG_SETUP, + AD4695_REG_SETUP_LDO_EN, + FIELD_PREP(AD4695_REG_SETUP_LDO_EN, + use_internal_ldo_supply ? 1 : 0)); + if (ret) + return ret; + + /* configure reference supply */ + + if (device_property_present(dev, "adi,no-ref-current-limit")) { + ret = regmap_set_bits(st->regmap, AD4695_REG_REF_CTRL, + AD4695_REG_REF_CTRL_OV_MODE); + if (ret) + return ret; + } + + if (device_property_present(dev, "adi,no-ref-high-z")) { + if (use_internal_ref_buffer) + return dev_err_probe(dev, -EINVAL, + "Cannot disable high-Z mode for internal reference buffer\n"); + + ret = regmap_clear_bits(st->regmap, AD4695_REG_REF_CTRL, + AD4695_REG_REF_CTRL_REFHIZ_EN); + if (ret) + return ret; + } + + ret = ad4695_set_ref_voltage(st, st->vref_mv); + if (ret) + return ret; + + if (use_internal_ref_buffer) { + ret = regmap_set_bits(st->regmap, AD4695_REG_REF_CTRL, + AD4695_REG_REF_CTRL_REFBUF_EN); + if (ret) + return ret; + + /* Give the capacitor some time to charge up. */ + msleep(AD4695_T_REFBUF_MS); + } + + ret = ad4695_parse_channel_cfg(st); + if (ret) + return ret; + + indio_dev->name = st->chip_info->name; + indio_dev->info = &ad4695_info; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->channels = st->iio_chan; + indio_dev->num_channels = st->chip_info->num_voltage_inputs + 1; + + return devm_iio_device_register(dev, indio_dev); +} + +static const struct spi_device_id ad4695_spi_id_table[] = { + { .name = "ad4695", .driver_data = (kernel_ulong_t)&ad4695_chip_info }, + { .name = "ad4696", .driver_data = (kernel_ulong_t)&ad4696_chip_info }, + { .name = "ad4697", .driver_data = (kernel_ulong_t)&ad4697_chip_info }, + { .name = "ad4698", .driver_data = (kernel_ulong_t)&ad4698_chip_info }, + { } +}; +MODULE_DEVICE_TABLE(spi, ad4695_spi_id_table); + +static const struct of_device_id ad4695_of_match_table[] = { + { .compatible = "adi,ad4695", .data = &ad4695_chip_info, }, + { .compatible = "adi,ad4696", .data = &ad4696_chip_info, }, + { .compatible = "adi,ad4697", .data = &ad4697_chip_info, }, + { .compatible = "adi,ad4698", .data = &ad4698_chip_info, }, + { } +}; +MODULE_DEVICE_TABLE(of, ad4695_of_match_table); + +static struct spi_driver ad4695_driver = { + .driver = { + .name = "ad4695", + .of_match_table = ad4695_of_match_table, + }, + .probe = ad4695_probe, + .id_table = ad4695_spi_id_table, +}; +module_spi_driver(ad4695_driver); + +MODULE_AUTHOR("Ramona Gradinariu <ramona.gradinariu@analog.com>"); +MODULE_AUTHOR("David Lechner <dlechner@baylibre.com>"); +MODULE_DESCRIPTION("Analog Devices AD4695 ADC driver"); +MODULE_LICENSE("GPL"); |