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([2402:e280:21d3:2:5455:eccf:e73:de96]) by smtp.gmail.com with ESMTPSA id 41be03b00d2f7-bad33c801d1sm6582780a12.7.2025.11.09.06.11.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 09 Nov 2025 06:11:58 -0800 (PST) From: Ajith Anandhan To: jic23@kernel.org Cc: dlechner@baylibre.com, nuno.sa@analog.com, andy@kernel.org, robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org, linux-iio@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Ajith Anandhan Subject: [PATCH v2 2/2] iio: adc: Add support for TI ADS1120 Date: Sun, 9 Nov 2025 19:41:19 +0530 Message-Id: <20251109141119.561756-3-ajithanandhan0406@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20251109141119.561756-1-ajithanandhan0406@gmail.com> References: <20251109141119.561756-1-ajithanandhan0406@gmail.com> Precedence: bulk X-Mailing-List: linux-iio@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Add driver for the Texas Instruments ADS1120, a precision 16-bit analog-to-digital converter with an SPI interface. The driver supports: - Differential and single-ended input channels - Configurable gain (1-128 for differential, 1-4 for single-ended) - Internal 2.048V reference - Single-shot conversion mode Also update MAINTAINER document. Signed-off-by: Ajith Anandhan --- MAINTAINERS | 7 + drivers/iio/adc/Kconfig | 10 + drivers/iio/adc/Makefile | 1 + drivers/iio/adc/ti-ads1120.c | 631 +++++++++++++++++++++++++++++++++++ 4 files changed, 649 insertions(+) create mode 100644 drivers/iio/adc/ti-ads1120.c diff --git a/MAINTAINERS b/MAINTAINERS index 3da2c26a7..1efe88fc9 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -25613,6 +25613,13 @@ S: Maintained F: Documentation/devicetree/bindings/iio/adc/ti,ads1119.yaml F: drivers/iio/adc/ti-ads1119.c +TI ADS1120 ADC DRIVER +M: Ajith Anandhan +L: linux-iio@vger.kernel.org +S: Maintained +F: Documentation/devicetree/bindings/iio/adc/ti,ads1120.yaml +F: drivers/iio/adc/ti-ads1120.c + TI ADS7924 ADC DRIVER M: Hugo Villeneuve L: linux-iio@vger.kernel.org diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig index 58a14e683..afb7895dd 100644 --- a/drivers/iio/adc/Kconfig +++ b/drivers/iio/adc/Kconfig @@ -1655,6 +1655,16 @@ config TI_ADS1119 This driver can also be built as a module. If so, the module will be called ti-ads1119. +config TI_ADS1120 + tristate "Texas Instruments ADS1120" + depends on SPI + help + Say yes here to build support for Texas Instruments ADS1120 + 4-channel, 2kSPS, 16-bit delta-sigma ADC. + + This driver can also be built as module. If so, the module + will be called ti-ads1120. + config TI_ADS124S08 tristate "Texas Instruments ADS124S08" depends on SPI diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile index d008f78dc..49c56b459 100644 --- a/drivers/iio/adc/Makefile +++ b/drivers/iio/adc/Makefile @@ -144,6 +144,7 @@ obj-$(CONFIG_TI_ADC161S626) += ti-adc161s626.o obj-$(CONFIG_TI_ADS1015) += ti-ads1015.o obj-$(CONFIG_TI_ADS1100) += ti-ads1100.o obj-$(CONFIG_TI_ADS1119) += ti-ads1119.o +obj-$(CONFIG_TI_ADS1120) += ti-ads1120.o obj-$(CONFIG_TI_ADS124S08) += ti-ads124s08.o obj-$(CONFIG_TI_ADS1298) += ti-ads1298.o obj-$(CONFIG_TI_ADS131E08) += ti-ads131e08.o diff --git a/drivers/iio/adc/ti-ads1120.c b/drivers/iio/adc/ti-ads1120.c new file mode 100644 index 000000000..1e1871b74 --- /dev/null +++ b/drivers/iio/adc/ti-ads1120.c @@ -0,0 +1,631 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * TI ADS1120 4-channel, 2kSPS, 16-bit delta-sigma ADC + * + * Datasheet: https://www.ti.com/lit/gpn/ads1120 + * + * Copyright (C) 2025 Ajith Anandhan + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + + +/* Commands */ +#define ADS1120_CMD_RESET 0x06 +#define ADS1120_CMD_START 0x08 +#define ADS1120_CMD_PWRDWN 0x02 +#define ADS1120_CMD_RDATA 0x10 +#define ADS1120_CMD_RREG 0x20 +#define ADS1120_CMD_WREG 0x40 + +/* Registers */ +#define ADS1120_REG_CONFIG0 0x00 +#define ADS1120_REG_CONFIG1 0x01 +#define ADS1120_REG_CONFIG2 0x02 +#define ADS1120_REG_CONFIG3 0x03 + +/* Config Register 0 bit definitions */ +#define ADS1120_CFG0_MUX_MASK GENMASK(7, 4) +/* Differential inputs */ +#define ADS1120_CFG0_MUX_AIN0_AIN1 0 +#define ADS1120_CFG0_MUX_AIN0_AIN2 1 +#define ADS1120_CFG0_MUX_AIN0_AIN3 2 +#define ADS1120_CFG0_MUX_AIN1_AIN2 3 +#define ADS1120_CFG0_MUX_AIN1_AIN3 4 +#define ADS1120_CFG0_MUX_AIN2_AIN3 5 +#define ADS1120_CFG0_MUX_AIN1_AIN0 6 +#define ADS1120_CFG0_MUX_AIN3_AIN2 7 +/* Single-ended inputs */ +#define ADS1120_CFG0_MUX_AIN0_AVSS 8 +#define ADS1120_CFG0_MUX_AIN1_AVSS 9 +#define ADS1120_CFG0_MUX_AIN2_AVSS 10 +#define ADS1120_CFG0_MUX_AIN3_AVSS 11 +/* Diagnostic inputs */ +#define ADS1120_CFG0_MUX_REFP_REFN_4 12 +#define ADS1120_CFG0_MUX_AVDD_AVSS_4 13 +#define ADS1120_CFG0_MUX_SHORTED 14 + +#define ADS1120_CFG0_GAIN_MASK GENMASK(3, 1) +#define ADS1120_CFG0_GAIN_1 0 +#define ADS1120_CFG0_GAIN_2 1 +#define ADS1120_CFG0_GAIN_4 2 +#define ADS1120_CFG0_GAIN_8 3 +#define ADS1120_CFG0_GAIN_16 4 +#define ADS1120_CFG0_GAIN_32 5 +#define ADS1120_CFG0_GAIN_64 6 +#define ADS1120_CFG0_GAIN_128 7 + +#define ADS1120_CFG0_PGA_BYPASS BIT(0) + +/* Config Register 1 bit definitions */ +#define ADS1120_CFG1_DR_MASK GENMASK(7, 5) +#define ADS1120_CFG1_DR_20SPS 0 +#define ADS1120_CFG1_DR_45SPS 1 +#define ADS1120_CFG1_DR_90SPS 2 +#define ADS1120_CFG1_DR_175SPS 3 +#define ADS1120_CFG1_DR_330SPS 4 +#define ADS1120_CFG1_DR_600SPS 5 +#define ADS1120_CFG1_DR_1000SPS 6 + +#define ADS1120_CFG1_MODE_MASK GENMASK(4, 3) +#define ADS1120_CFG1_MODE_NORMAL 0 +#define ADS1120_CFG1_MODE_DUTY 1 +#define ADS1120_CFG1_MODE_TURBO 2 + +#define ADS1120_CFG1_CM_MASK BIT(2) +#define ADS1120_CFG1_CM_SINGLE 0 +#define ADS1120_CFG1_CM_CONTINUOUS 1 + +#define ADS1120_CFG1_TS_EN BIT(1) +#define ADS1120_CFG1_BCS_EN BIT(0) + +/* Config Register 2 bit definitions */ +#define ADS1120_CFG2_VREF_MASK GENMASK(7, 6) +#define ADS1120_CFG2_VREF_INTERNAL 0 +#define ADS1120_CFG2_VREF_EXT_REFP0 1 +#define ADS1120_CFG2_VREF_EXT_AIN0 2 +#define ADS1120_CFG2_VREF_AVDD 3 + +#define ADS1120_CFG2_REJECT_MASK GENMASK(5, 4) +#define ADS1120_CFG2_REJECT_OFF 0 +#define ADS1120_CFG2_REJECT_50_60 1 +#define ADS1120_CFG2_REJECT_50 2 +#define ADS1120_CFG2_REJECT_60 3 + +#define ADS1120_CFG2_PSW_EN BIT(3) + +#define ADS1120_CFG2_IDAC_MASK GENMASK(2, 0) +#define ADS1120_CFG2_IDAC_OFF 0 +#define ADS1120_CFG2_IDAC_10UA 1 +#define ADS1120_CFG2_IDAC_50UA 2 +#define ADS1120_CFG2_IDAC_100UA 3 +#define ADS1120_CFG2_IDAC_250UA 4 +#define ADS1120_CFG2_IDAC_500UA 5 +#define ADS1120_CFG2_IDAC_1000UA 6 +#define ADS1120_CFG2_IDAC_1500UA 7 + +/* Config Register 3 bit definitions */ +#define ADS1120_CFG3_IDAC1_MASK GENMASK(7, 5) +#define ADS1120_CFG3_IDAC1_DISABLED 0 +#define ADS1120_CFG3_IDAC1_AIN0 1 +#define ADS1120_CFG3_IDAC1_AIN1 2 +#define ADS1120_CFG3_IDAC1_AIN2 3 +#define ADS1120_CFG3_IDAC1_AIN3 4 +#define ADS1120_CFG3_IDAC1_REFP0 5 +#define ADS1120_CFG3_IDAC1_REFN0 6 + +#define ADS1120_CFG3_IDAC2_MASK GENMASK(4, 2) +#define ADS1120_CFG3_IDAC2_DISABLED 0 +#define ADS1120_CFG3_IDAC2_AIN0 1 +#define ADS1120_CFG3_IDAC2_AIN1 2 +#define ADS1120_CFG3_IDAC2_AIN2 3 +#define ADS1120_CFG3_IDAC2_AIN3 4 +#define ADS1120_CFG3_IDAC2_REFP0 5 +#define ADS1120_CFG3_IDAC2_REFN0 6 + +#define ADS1120_CFG3_DRDYM_MASK BIT(1) +#define ADS1120_CFG3_DRDYM_DRDY_ONLY 0 +#define ADS1120_CFG3_DRDYM_BOTH 1 + +/* Conversion time for 20 SPS */ +#define ADS1120_CONV_TIME_MS 51 + +/* Internal reference voltage in millivolts */ +#define ADS1120_VREF_INTERNAL_MV 2048 + + +struct ads1120_state { + struct spi_device *spi; + struct regmap *regmap; + /* + * Protects chip configuration and ADC reads to ensure + * consistent channel/gain settings during conversions. + */ + struct mutex lock; + + int vref_mv; + + /* DMA-safe buffer for SPI transfers */ + u8 data[4] __aligned(IIO_DMA_MINALIGN); +}; + + +static const int ads1120_gain_values[] = { 1, 2, 4, 8, 16, 32, 64, 128 }; +static const int ads1120_low_gain_values[] = { 1, 2, 4 }; + +/* Differential channel macro */ +#define ADS1120_DIFF_CHANNEL(index, chan1, chan2) \ +{ \ + .type = IIO_VOLTAGE, \ + .indexed = 1, \ + .channel = chan1, \ + .channel2 = chan2, \ + .differential = 1, \ + .address = index, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ + BIT(IIO_CHAN_INFO_SCALE), \ + .info_mask_separate_available = BIT(IIO_CHAN_INFO_SCALE), \ +} + +/* Single-ended channel macro */ +#define ADS1120_SINGLE_CHANNEL(index, chan) \ +{ \ + .type = IIO_VOLTAGE, \ + .indexed = 1, \ + .channel = chan, \ + .address = index, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ + BIT(IIO_CHAN_INFO_SCALE), \ + .info_mask_separate_available = BIT(IIO_CHAN_INFO_SCALE), \ +} + +/* Diagnostic channel macro */ +#define ADS1120_DIAG_CHANNEL(index, label) \ +{ \ + .type = IIO_VOLTAGE, \ + .indexed = 1, \ + .channel = index, \ + .address = index, \ + .extend_name = label, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ + BIT(IIO_CHAN_INFO_SCALE), \ + .info_mask_separate_available = BIT(IIO_CHAN_INFO_SCALE), \ +} + +static const struct iio_chan_spec ads1120_channels[] = { + /* Differential inputs */ + ADS1120_DIFF_CHANNEL(ADS1120_CFG0_MUX_AIN0_AIN1, 0, 1), + ADS1120_DIFF_CHANNEL(ADS1120_CFG0_MUX_AIN0_AIN2, 0, 2), + ADS1120_DIFF_CHANNEL(ADS1120_CFG0_MUX_AIN0_AIN3, 0, 3), + ADS1120_DIFF_CHANNEL(ADS1120_CFG0_MUX_AIN1_AIN2, 1, 2), + ADS1120_DIFF_CHANNEL(ADS1120_CFG0_MUX_AIN1_AIN3, 1, 3), + ADS1120_DIFF_CHANNEL(ADS1120_CFG0_MUX_AIN2_AIN3, 2, 3), + ADS1120_DIFF_CHANNEL(ADS1120_CFG0_MUX_AIN1_AIN0, 1, 0), + ADS1120_DIFF_CHANNEL(ADS1120_CFG0_MUX_AIN3_AIN2, 3, 2), + /* Single-ended inputs */ + ADS1120_SINGLE_CHANNEL(ADS1120_CFG0_MUX_AIN0_AVSS, 0), + ADS1120_SINGLE_CHANNEL(ADS1120_CFG0_MUX_AIN1_AVSS, 1), + ADS1120_SINGLE_CHANNEL(ADS1120_CFG0_MUX_AIN2_AVSS, 2), + ADS1120_SINGLE_CHANNEL(ADS1120_CFG0_MUX_AIN3_AVSS, 3), + /* Diagnostic inputs */ + ADS1120_DIAG_CHANNEL(ADS1120_CFG0_MUX_REFP_REFN_4, "ref_div4"), + ADS1120_DIAG_CHANNEL(ADS1120_CFG0_MUX_AVDD_AVSS_4, "avdd_div4"), + ADS1120_DIAG_CHANNEL(ADS1120_CFG0_MUX_SHORTED, "shorted"), +}; + +static bool ads1120_is_differential_channel(const struct iio_chan_spec *chan) +{ + return chan->address <= ADS1120_CFG0_MUX_AIN3_AIN2; +} + +static int ads1120_write_cmd(struct ads1120_state *st, u8 cmd) +{ + st->data[0] = cmd; + return spi_write(st->spi, st->data, sizeof(st->data[0])); +} + +static int ads1120_reset(struct ads1120_state *st) +{ + int ret; + + ret = ads1120_write_cmd(st, ADS1120_CMD_RESET); + if (ret) + return ret; + + /* + * Datasheet specifies reset takes 50us + 32 * t(CLK) + * where t(CLK) = 1/4.096MHz (~0.24us). + * 50us + 32 * 0.24us = ~58us. Use 200us to be safe. + */ + fsleep(200); + + regcache_mark_dirty(st->regmap); + + return 0; +} + +static int ads1120_set_mux(struct ads1120_state *st, u8 mux_val) +{ + if (mux_val > ADS1120_CFG0_MUX_SHORTED) + return -EINVAL; + + return regmap_update_bits(st->regmap, ADS1120_REG_CONFIG0, + ADS1120_CFG0_MUX_MASK, + FIELD_PREP(ADS1120_CFG0_MUX_MASK, mux_val)); +} + +static int ads1120_set_gain(struct ads1120_state *st, int gain_val) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(ads1120_gain_values); i++) { + if (ads1120_gain_values[i] == gain_val) + break; + } + + if (i == ARRAY_SIZE(ads1120_gain_values)) + return -EINVAL; + + return regmap_update_bits(st->regmap, ADS1120_REG_CONFIG0, + ADS1120_CFG0_GAIN_MASK, + FIELD_PREP(ADS1120_CFG0_GAIN_MASK, i)); +} + +static int ads1120_get_gain(struct ads1120_state *st) +{ + unsigned int val; + int ret; + + ret = regmap_read(st->regmap, ADS1120_REG_CONFIG0, &val); + if (ret) + return ret; + + return ads1120_gain_values[FIELD_GET(ADS1120_CFG0_GAIN_MASK, val)]; +} + +static int ads1120_read_raw_adc(struct ads1120_state *st, int *val) +{ + int ret; + struct spi_transfer xfer[2] = { + { + .tx_buf = st->data, + .len = 1, + }, { + .rx_buf = st->data, + .len = 2, + } + }; + + st->data[0] = ADS1120_CMD_RDATA; + + ret = spi_sync_transfer(st->spi, xfer, ARRAY_SIZE(xfer)); + if (ret) + return ret; + + *val = sign_extend32(get_unaligned_be16(st->data), 15); + + return 0; +} + +static int ads1120_read_measurement(struct ads1120_state *st, + const struct iio_chan_spec *chan, int *val) +{ + int ret; + + ret = ads1120_set_mux(st, chan->address); + if (ret) + return ret; + + ret = ads1120_write_cmd(st, ADS1120_CMD_START); + if (ret) + return ret; + + msleep(ADS1120_CONV_TIME_MS); + + return ads1120_read_raw_adc(st, val); +} + +static int ads1120_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + struct ads1120_state *st = iio_priv(indio_dev); + int ret, gain; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + guard(mutex)(&st->lock); + ret = ads1120_read_measurement(st, chan, val); + if (ret) + return ret; + return IIO_VAL_INT; + + case IIO_CHAN_INFO_SCALE: + /* + * Scale = Vref / (gain * 2^15) + * Return in format: val / 2^val2 + */ + gain = ads1120_get_gain(st); + if (gain < 0) + return gain; + + *val = st->vref_mv; + *val2 = gain * 15; + return IIO_VAL_FRACTIONAL_LOG2; + + default: + return -EINVAL; + } +} + +static int ads1120_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int val, int val2, long mask) +{ + struct ads1120_state *st = iio_priv(indio_dev); + + switch (mask) { + case IIO_CHAN_INFO_SCALE: + /* + * Validate gain for single-ended and diagnostic channels. + * These channels require PGA bypass and support only + * gains 1, 2, and 4. + */ + if (!ads1120_is_differential_channel(chan) && val > 4) + return -EINVAL; + + guard(mutex)(&st->lock); + return ads1120_set_gain(st, val); + + default: + return -EINVAL; + } +} + +static int ads1120_read_avail(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + const int **vals, int *type, int *length, + long mask) +{ + switch (mask) { + case IIO_CHAN_INFO_SCALE: + if (ads1120_is_differential_channel(chan)) { + *vals = ads1120_gain_values; + *length = ARRAY_SIZE(ads1120_gain_values); + } else { + *vals = ads1120_low_gain_values; + *length = ARRAY_SIZE(ads1120_low_gain_values); + } + *type = IIO_VAL_INT; + return IIO_AVAIL_LIST; + + default: + return -EINVAL; + } +} + +static const struct iio_info ads1120_info = { + .read_raw = ads1120_read_raw, + .write_raw = ads1120_write_raw, + .read_avail = ads1120_read_avail, +}; + +/* Regmap read function for ADS1120 */ +static int ads1120_regmap_read(void *context, const void *reg_buf, + size_t reg_size, void *val_buf, size_t val_size) +{ + struct ads1120_state *st = context; + u8 reg = *(u8 *)reg_buf; + u8 *val = val_buf; + int ret; + struct spi_transfer xfer[2] = { + { + .tx_buf = st->data, + .len = 1, + }, { + .rx_buf = val, + .len = val_size, + } + }; + + if (reg > ADS1120_REG_CONFIG3) + return -EINVAL; + + /* RREG command: 0010rr00 where rr is register address */ + st->data[0] = ADS1120_CMD_RREG | (reg << 2); + + ret = spi_sync_transfer(st->spi, xfer, ARRAY_SIZE(xfer)); + if (ret) + return ret; + + return 0; +} + +/* Regmap write function for ADS1120 */ +static int ads1120_regmap_write(void *context, const void *data, size_t count) +{ + struct ads1120_state *st = context; + const u8 *buf = data; + + if (count != 2) + return -EINVAL; + + /* WREG command: 0100rr00 where rr is register address */ + st->data[0] = ADS1120_CMD_WREG | (buf[0] << 2); + st->data[1] = buf[1]; + + return spi_write(st->spi, st->data, 2); +} + +static const struct regmap_bus ads1120_regmap_bus = { + .read = ads1120_regmap_read, + .write = ads1120_regmap_write, + .reg_format_endian_default = REGMAP_ENDIAN_BIG, + .val_format_endian_default = REGMAP_ENDIAN_BIG, +}; + +static const struct regmap_config ads1120_regmap_config = { + .reg_bits = 8, + .val_bits = 8, + .max_register = ADS1120_REG_CONFIG3, + .cache_type = REGCACHE_FLAT, +}; + +static int ads1120_init(struct ads1120_state *st) +{ + int ret; + + ret = ads1120_reset(st); + if (ret) + return dev_err_probe(&st->spi->dev, ret, + "Failed to reset device\n"); + + /* + * Configure Register 0: + * - Input MUX: AIN0/AVSS + * - Gain: 1 + * - PGA bypass enabled. When gain is set > 4, this bit is + * automatically ignored by the hardware and PGA is enabled, + * so it's safe to leave it set. + */ + ret = regmap_write(st->regmap, ADS1120_REG_CONFIG0, + FIELD_PREP(ADS1120_CFG0_MUX_MASK, + ADS1120_CFG0_MUX_AIN0_AVSS) | + FIELD_PREP(ADS1120_CFG0_GAIN_MASK, + ADS1120_CFG0_GAIN_1) | + ADS1120_CFG0_PGA_BYPASS); + if (ret) + return ret; + + /* + * Configure Register 1: + * - Data rate: 20 SPS (for single-shot mode) + * - Operating mode: Normal + * - Conversion mode: Single-shot + * - Temperature sensor: Disabled + * - Burnout current: Disabled + */ + ret = regmap_write(st->regmap, ADS1120_REG_CONFIG1, + FIELD_PREP(ADS1120_CFG1_DR_MASK, + ADS1120_CFG1_DR_20SPS) | + FIELD_PREP(ADS1120_CFG1_MODE_MASK, + ADS1120_CFG1_MODE_NORMAL) | + FIELD_PREP(ADS1120_CFG1_CM_MASK, + ADS1120_CFG1_CM_SINGLE) | + FIELD_PREP(ADS1120_CFG1_TS_EN, 0) | + FIELD_PREP(ADS1120_CFG1_BCS_EN, 0)); + if (ret) + return ret; + + /* + * Configure Register 2: + * - Voltage reference: Internal 2.048V + * - 50/60Hz rejection: Off + * - Power switch: Disabled + * - IDAC current: Off + */ + ret = regmap_write(st->regmap, ADS1120_REG_CONFIG2, + FIELD_PREP(ADS1120_CFG2_VREF_MASK, + ADS1120_CFG2_VREF_INTERNAL) | + FIELD_PREP(ADS1120_CFG2_REJECT_MASK, + ADS1120_CFG2_REJECT_OFF) | + FIELD_PREP(ADS1120_CFG2_PSW_EN, 0) | + FIELD_PREP(ADS1120_CFG2_IDAC_MASK, + ADS1120_CFG2_IDAC_OFF)); + if (ret) + return ret; + + /* + * Configure Register 3: + * - IDAC1: Disabled + * - IDAC2: Disabled + * - DRDY mode: Only reflects data ready status + */ + ret = regmap_write(st->regmap, ADS1120_REG_CONFIG3, + FIELD_PREP(ADS1120_CFG3_IDAC1_MASK, + ADS1120_CFG3_IDAC1_DISABLED) | + FIELD_PREP(ADS1120_CFG3_IDAC2_MASK, + ADS1120_CFG3_IDAC2_DISABLED) | + FIELD_PREP(ADS1120_CFG3_DRDYM_MASK, + ADS1120_CFG3_DRDYM_DRDY_ONLY)); + if (ret) + return ret; + + st->vref_mv = ADS1120_VREF_INTERNAL_MV; + + return 0; +} + +static int ads1120_probe(struct spi_device *spi) +{ + struct device *dev = &spi->dev; + struct iio_dev *indio_dev; + struct ads1120_state *st; + int ret; + + indio_dev = devm_iio_device_alloc(dev, sizeof(*st)); + if (!indio_dev) + return -ENOMEM; + + st = iio_priv(indio_dev); + st->spi = spi; + + ret = devm_mutex_init(dev, &st->lock); + if (ret) + return ret; + + st->regmap = devm_regmap_init(dev, &ads1120_regmap_bus, st, + &ads1120_regmap_config); + if (IS_ERR(st->regmap)) + return dev_err_probe(dev, PTR_ERR(st->regmap), + "Failed to initialize regmap\n"); + + indio_dev->name = "ads1120"; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->channels = ads1120_channels; + indio_dev->num_channels = ARRAY_SIZE(ads1120_channels); + indio_dev->info = &ads1120_info; + + ret = ads1120_init(st); + if (ret) + return dev_err_probe(dev, ret, + "Failed to initialize device\n"); + + return devm_iio_device_register(dev, indio_dev); +} + +static const struct of_device_id ads1120_of_match[] = { + { .compatible = "ti,ads1120" }, + { } +}; +MODULE_DEVICE_TABLE(of, ads1120_of_match); + +static const struct spi_device_id ads1120_id[] = { + { "ads1120" }, + { } +}; +MODULE_DEVICE_TABLE(spi, ads1120_id); + +static struct spi_driver ads1120_driver = { + .driver = { + .name = "ads1120", + .of_match_table = ads1120_of_match, + }, + .probe = ads1120_probe, + .id_table = ads1120_id, +}; +module_spi_driver(ads1120_driver); + +MODULE_AUTHOR("Ajith Anandhan "); +MODULE_DESCRIPTION("Texas Instruments ADS1120 ADC driver"); +MODULE_LICENSE("GPL"); -- 2.34.1