diff options
Diffstat (limited to 'drivers/iio/adc/ad4170-4.c')
| -rw-r--r-- | drivers/iio/adc/ad4170-4.c | 3027 |
1 files changed, 3027 insertions, 0 deletions
diff --git a/drivers/iio/adc/ad4170-4.c b/drivers/iio/adc/ad4170-4.c new file mode 100644 index 000000000000..6cd84d6fb08b --- /dev/null +++ b/drivers/iio/adc/ad4170-4.c @@ -0,0 +1,3027 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Analog Devices AD4170-4 ADC driver + * + * Copyright (C) 2025 Analog Devices, Inc. + * Author: Ana-Maria Cusco <ana-maria.cusco@analog.com> + * Author: Marcelo Schmitt <marcelo.schmitt@analog.com> + */ + +#include <linux/array_size.h> +#include <linux/bitfield.h> +#include <linux/bitmap.h> +#include <linux/bitops.h> +#include <linux/bits.h> +#include <linux/cleanup.h> +#include <linux/clk.h> +#include <linux/clk-provider.h> +#include <linux/delay.h> +#include <linux/device.h> +#include <linux/err.h> +#include <linux/gpio/driver.h> +#include <linux/iio/buffer.h> +#include <linux/iio/iio.h> +#include <linux/iio/trigger.h> +#include <linux/iio/trigger_consumer.h> +#include <linux/iio/triggered_buffer.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/math64.h> +#include <linux/minmax.h> +#include <linux/module.h> +#include <linux/property.h> +#include <linux/regmap.h> +#include <linux/regulator/consumer.h> +#include <linux/spi/spi.h> +#include <linux/time.h> +#include <linux/types.h> +#include <linux/unaligned.h> +#include <linux/units.h> +#include <linux/util_macros.h> + +/* + * AD4170 registers + * Multibyte register addresses point to the most significant byte which is the + * address to use to get the most significant byte first (address accessed is + * decremented by one for each data byte) + * + * Each register address define follows the AD4170_<REG_NAME>_REG format. + * Each mask follows the AD4170_<REG_NAME>_<FIELD_NAME> format. + * E.g. AD4170_PIN_MUXING_DIG_AUX1_CTRL_MSK is for accessing DIG_AUX1_CTRL field + * of PIN_MUXING_REG. + * Each constant follows the AD4170_<REG_NAME>_<FIELD_NAME>_<FUNCTION> format. + * E.g. AD4170_PIN_MUXING_DIG_AUX1_DISABLED is the value written to + * DIG_AUX1_CTRL field of PIN_MUXING register to disable DIG_AUX1 pin. + * Some register names and register field names are shortened versions of + * their datasheet counterpart names to provide better code readability. + */ +#define AD4170_CONFIG_A_REG 0x00 +#define AD4170_DATA_24B_REG 0x1E +#define AD4170_PIN_MUXING_REG 0x69 +#define AD4170_CLOCK_CTRL_REG 0x6B +#define AD4170_ADC_CTRL_REG 0x71 +#define AD4170_CHAN_EN_REG 0x79 +#define AD4170_CHAN_SETUP_REG(x) (0x81 + 4 * (x)) +#define AD4170_CHAN_MAP_REG(x) (0x83 + 4 * (x)) +#define AD4170_MISC_REG(x) (0xC1 + 14 * (x)) +#define AD4170_AFE_REG(x) (0xC3 + 14 * (x)) +#define AD4170_FILTER_REG(x) (0xC5 + 14 * (x)) +#define AD4170_FILTER_FS_REG(x) (0xC7 + 14 * (x)) +#define AD4170_OFFSET_REG(x) (0xCA + 14 * (x)) +#define AD4170_GAIN_REG(x) (0xCD + 14 * (x)) +#define AD4170_V_BIAS_REG 0x135 +#define AD4170_CURRENT_SRC_REG(x) (0x139 + 2 * (x)) +#define AD4170_GPIO_MODE_REG 0x191 +#define AD4170_GPIO_OUTPUT_REG 0x193 +#define AD4170_GPIO_INPUT_REG 0x195 +#define AD4170_ADC_CTRL_CONT_READ_EXIT_REG 0x200 /* virtual reg */ + +#define AD4170_REG_READ_MASK BIT(14) + +/* AD4170_CONFIG_A_REG - INTERFACE_CONFIG_A REGISTER */ +#define AD4170_SW_RESET_MSK (BIT(7) | BIT(0)) + +/* AD4170_PIN_MUXING_REG */ +#define AD4170_PIN_MUXING_DIG_AUX1_CTRL_MSK GENMASK(5, 4) + +/* AD4170_CLOCK_CTRL_REG */ +#define AD4170_CLOCK_CTRL_CLOCKSEL_MSK GENMASK(1, 0) + +/* AD4170_ADC_CTRL_REG */ +#define AD4170_ADC_CTRL_MULTI_DATA_REG_SEL_MSK BIT(7) +#define AD4170_ADC_CTRL_CONT_READ_MSK GENMASK(5, 4) +#define AD4170_ADC_CTRL_MODE_MSK GENMASK(3, 0) + +/* AD4170_CHAN_EN_REG */ +#define AD4170_CHAN_EN(ch) BIT(ch) + +/* AD4170_CHAN_SETUP_REG */ +#define AD4170_CHAN_SETUP_SETUP_MSK GENMASK(2, 0) + +/* AD4170_CHAN_MAP_REG */ +#define AD4170_CHAN_MAP_AINP_MSK GENMASK(12, 8) +#define AD4170_CHAN_MAP_AINM_MSK GENMASK(4, 0) + +/* AD4170_MISC_REG */ +#define AD4170_MISC_CHOP_IEXC_MSK GENMASK(15, 14) +#define AD4170_MISC_CHOP_ADC_MSK GENMASK(9, 8) + +/* AD4170_AFE_REG */ +#define AD4170_AFE_REF_BUF_M_MSK GENMASK(11, 10) +#define AD4170_AFE_REF_BUF_P_MSK GENMASK(9, 8) +#define AD4170_AFE_REF_SELECT_MSK GENMASK(6, 5) +#define AD4170_AFE_BIPOLAR_MSK BIT(4) +#define AD4170_AFE_PGA_GAIN_MSK GENMASK(3, 0) + +/* AD4170_FILTER_REG */ +#define AD4170_FILTER_FILTER_TYPE_MSK GENMASK(3, 0) + +/* AD4170_CURRENT_SRC_REG */ +#define AD4170_CURRENT_SRC_I_OUT_PIN_MSK GENMASK(12, 8) +#define AD4170_CURRENT_SRC_I_OUT_VAL_MSK GENMASK(2, 0) + +/* AD4170_GPIO_MODE_REG */ +#define AD4170_GPIO_MODE_GPIO0_MSK GENMASK(1, 0) +#define AD4170_GPIO_MODE_GPIO1_MSK GENMASK(3, 2) +#define AD4170_GPIO_MODE_GPIO2_MSK GENMASK(5, 4) +#define AD4170_GPIO_MODE_GPIO3_MSK GENMASK(7, 6) + +/* AD4170_GPIO_OUTPUT_REG */ +#define AD4170_GPIO_OUTPUT_GPIO_MSK(x) BIT(x) + +/* AD4170 register constants */ + +/* AD4170_CLOCK_CTRL_REG constants */ +#define AD4170_CLOCK_CTRL_CLOCKSEL_INT 0x0 +#define AD4170_CLOCK_CTRL_CLOCKSEL_INT_OUT 0x1 +#define AD4170_CLOCK_CTRL_CLOCKSEL_EXT 0x2 +#define AD4170_CLOCK_CTRL_CLOCKSEL_EXT_XTAL 0x3 + +/* AD4170_CHAN_MAP_REG constants */ +#define AD4170_CHAN_MAP_AIN(x) (x) +#define AD4170_CHAN_MAP_TEMP_SENSOR 17 +#define AD4170_CHAN_MAP_AVDD_AVSS_P 18 +#define AD4170_CHAN_MAP_AVDD_AVSS_N 18 +#define AD4170_CHAN_MAP_IOVDD_DGND_P 19 +#define AD4170_CHAN_MAP_IOVDD_DGND_N 19 +#define AD4170_CHAN_MAP_AVSS 23 +#define AD4170_CHAN_MAP_DGND 24 +#define AD4170_CHAN_MAP_REFIN1_P 25 +#define AD4170_CHAN_MAP_REFIN1_N 26 +#define AD4170_CHAN_MAP_REFIN2_P 27 +#define AD4170_CHAN_MAP_REFIN2_N 28 +#define AD4170_CHAN_MAP_REFOUT 29 + +/* AD4170_MISC_REG constants */ +#define AD4170_MISC_CHOP_IEXC_PAIR1 0x1 +#define AD4170_MISC_CHOP_IEXC_PAIR2 0x2 +#define AD4170_MISC_CHOP_IEXC_BOTH 0x3 + +/* AD4170_PIN_MUXING_REG constants */ +#define AD4170_PIN_MUXING_DIG_AUX1_DISABLED 0x0 +#define AD4170_PIN_MUXING_DIG_AUX1_RDY 0x1 + +/* AD4170_ADC_CTRL_REG constants */ +#define AD4170_ADC_CTRL_MODE_CONT 0x0 +#define AD4170_ADC_CTRL_MODE_SINGLE 0x4 +#define AD4170_ADC_CTRL_MODE_IDLE 0x7 + +#define AD4170_ADC_CTRL_CONT_READ_DISABLE 0x0 +#define AD4170_ADC_CTRL_CONT_READ_ENABLE 0x1 + +/* AD4170_FILTER_REG constants */ +#define AD4170_FILTER_FILTER_TYPE_SINC5_AVG 0x0 +#define AD4170_FILTER_FILTER_TYPE_SINC5 0x4 +#define AD4170_FILTER_FILTER_TYPE_SINC3 0x6 + +/* AD4170_CURRENT_SRC_REG constants */ +#define AD4170_CURRENT_SRC_I_OUT_PIN_AIN(x) (x) +#define AD4170_CURRENT_SRC_I_OUT_PIN_GPIO(x) ((x) + 17) + +/* AD4170_GPIO_MODE_REG constants */ +#define AD4170_GPIO_MODE_GPIO_INPUT 1 +#define AD4170_GPIO_MODE_GPIO_OUTPUT 2 + +/* Device properties and auxiliary constants */ + +#define AD4170_NUM_ANALOG_PINS 9 +#define AD4170_NUM_GPIO_PINS 4 +#define AD4170_MAX_ADC_CHANNELS 16 +#define AD4170_MAX_IIO_CHANNELS (AD4170_MAX_ADC_CHANNELS + 1) +#define AD4170_MAX_ANALOG_PINS 8 +#define AD4170_MAX_SETUPS 8 +#define AD4170_INVALID_SETUP 9 +#define AD4170_SPI_INST_PHASE_LEN 2 +#define AD4170_SPI_MAX_XFER_LEN 6 +#define AD4170_NUM_CURRENT_SRC 4 +#define AD4170_DEFAULT_SAMP_RATE (125 * HZ_PER_KHZ) + +#define AD4170_INT_REF_2_5V 2500000 + +/* Internal and external clock properties */ +#define AD4170_INT_CLOCK_16MHZ (16 * HZ_PER_MHZ) +#define AD4170_EXT_CLOCK_MHZ_MIN (1 * HZ_PER_MHZ) +#define AD4170_EXT_CLOCK_MHZ_MAX (17 * HZ_PER_MHZ) + +#define AD4170_NUM_PGA_OPTIONS 10 + +/* Digital filter properties */ +#define AD4170_SINC3_MIN_FS 4 +#define AD4170_SINC3_MAX_FS 65532 +#define AD4170_SINC5_MIN_FS 1 +#define AD4170_SINC5_MAX_FS 256 + +#define AD4170_GAIN_REG_DEFAULT 0x555555 + +#define AD4170_ADC_CTRL_CONT_READ_EXIT 0xA5 + +/* Analog pin functions */ +#define AD4170_PIN_UNASSIGNED 0x00 +#define AD4170_PIN_ANALOG_IN 0x01 +#define AD4170_PIN_CURRENT_OUT 0x02 +#define AD4170_PIN_VBIAS 0x04 + +/* GPIO pin functions */ +#define AD4170_GPIO_UNASSIGNED 0x00 +#define AD4170_GPIO_AC_EXCITATION 0x02 +#define AD4170_GPIO_OUTPUT 0x04 + +/* Current source */ +#define AD4170_CURRENT_SRC_DISABLED 0xFF + +static const unsigned int ad4170_reg_size[] = { + [AD4170_CONFIG_A_REG] = 1, + [AD4170_DATA_24B_REG] = 3, + [AD4170_PIN_MUXING_REG] = 2, + [AD4170_CLOCK_CTRL_REG] = 2, + [AD4170_ADC_CTRL_REG] = 2, + [AD4170_CHAN_EN_REG] = 2, + /* + * CHANNEL_SETUP and CHANNEL_MAP register are all 2 byte size each and + * their addresses are interleaved such that we have CHANNEL_SETUP0 + * address followed by CHANNEL_MAP0 address, followed by CHANNEL_SETUP1, + * and so on until CHANNEL_MAP15. + * Thus, initialize the register size for them only once. + */ + [AD4170_CHAN_SETUP_REG(0) ... AD4170_CHAN_MAP_REG(AD4170_MAX_ADC_CHANNELS - 1)] = 2, + /* + * MISC, AFE, FILTER, FILTER_FS, OFFSET, and GAIN register addresses are + * also interleaved but MISC, AFE, FILTER, FILTER_FS, OFFSET are 16-bit + * while OFFSET, GAIN are 24-bit registers so we can't init them all to + * the same size. + */ + [AD4170_MISC_REG(0) ... AD4170_FILTER_FS_REG(0)] = 2, + [AD4170_MISC_REG(1) ... AD4170_FILTER_FS_REG(1)] = 2, + [AD4170_MISC_REG(2) ... AD4170_FILTER_FS_REG(2)] = 2, + [AD4170_MISC_REG(3) ... AD4170_FILTER_FS_REG(3)] = 2, + [AD4170_MISC_REG(4) ... AD4170_FILTER_FS_REG(4)] = 2, + [AD4170_MISC_REG(5) ... AD4170_FILTER_FS_REG(5)] = 2, + [AD4170_MISC_REG(6) ... AD4170_FILTER_FS_REG(6)] = 2, + [AD4170_MISC_REG(7) ... AD4170_FILTER_FS_REG(7)] = 2, + [AD4170_OFFSET_REG(0) ... AD4170_GAIN_REG(0)] = 3, + [AD4170_OFFSET_REG(1) ... AD4170_GAIN_REG(1)] = 3, + [AD4170_OFFSET_REG(2) ... AD4170_GAIN_REG(2)] = 3, + [AD4170_OFFSET_REG(3) ... AD4170_GAIN_REG(3)] = 3, + [AD4170_OFFSET_REG(4) ... AD4170_GAIN_REG(4)] = 3, + [AD4170_OFFSET_REG(5) ... AD4170_GAIN_REG(5)] = 3, + [AD4170_OFFSET_REG(6) ... AD4170_GAIN_REG(6)] = 3, + [AD4170_OFFSET_REG(7) ... AD4170_GAIN_REG(7)] = 3, + [AD4170_V_BIAS_REG] = 2, + [AD4170_CURRENT_SRC_REG(0) ... AD4170_CURRENT_SRC_REG(3)] = 2, + [AD4170_GPIO_MODE_REG] = 2, + [AD4170_GPIO_OUTPUT_REG] = 2, + [AD4170_GPIO_INPUT_REG] = 2, + [AD4170_ADC_CTRL_CONT_READ_EXIT_REG] = 0, +}; + +enum ad4170_ref_buf { + AD4170_REF_BUF_PRE, /* Pre-charge referrence buffer */ + AD4170_REF_BUF_FULL, /* Full referrence buffering */ + AD4170_REF_BUF_BYPASS, /* Bypass referrence buffering */ +}; + +/* maps adi,positive/negative-reference-buffer property values to enum */ +static const char * const ad4170_ref_buf_str[] = { + [AD4170_REF_BUF_PRE] = "precharge", + [AD4170_REF_BUF_FULL] = "full", + [AD4170_REF_BUF_BYPASS] = "disabled", +}; + +enum ad4170_ref_select { + AD4170_REF_REFIN1, + AD4170_REF_REFIN2, + AD4170_REF_REFOUT, + AD4170_REF_AVDD, +}; + +enum ad4170_filter_type { + AD4170_SINC5_AVG, + AD4170_SINC5, + AD4170_SINC3, +}; + +enum ad4170_regulator { + AD4170_AVDD_SUP, + AD4170_AVSS_SUP, + AD4170_IOVDD_SUP, + AD4170_REFIN1P_SUP, + AD4170_REFIN1N_SUP, + AD4170_REFIN2P_SUP, + AD4170_REFIN2N_SUP, + AD4170_MAX_SUP, +}; + +static const char *const ad4170_clk_sel[] = { + "ext-clk", "xtal", +}; + +enum ad4170_int_pin_sel { + AD4170_INT_PIN_SDO, + AD4170_INT_PIN_DIG_AUX1, +}; + +static const char * const ad4170_int_pin_names[] = { + [AD4170_INT_PIN_SDO] = "sdo", + [AD4170_INT_PIN_DIG_AUX1] = "dig_aux1", +}; + +static const unsigned int ad4170_sinc3_filt_fs_tbl[] = { + 4, 8, 12, 16, 20, 40, 48, 80, /* 0 - 7 */ + 100, 256, 500, 1000, 5000, 8332, 10000, 25000, /* 8 - 15 */ + 50000, 65532, /* 16 - 17 */ +}; + +#define AD4170_MAX_FS_TBL_SIZE ARRAY_SIZE(ad4170_sinc3_filt_fs_tbl) + +static const unsigned int ad4170_sinc5_filt_fs_tbl[] = { + 1, 2, 4, 8, 12, 16, 20, 40, 48, 80, 100, 256, +}; + +static const unsigned int ad4170_iout_pin_tbl[] = { + AD4170_CURRENT_SRC_I_OUT_PIN_AIN(0), + AD4170_CURRENT_SRC_I_OUT_PIN_AIN(1), + AD4170_CURRENT_SRC_I_OUT_PIN_AIN(2), + AD4170_CURRENT_SRC_I_OUT_PIN_AIN(3), + AD4170_CURRENT_SRC_I_OUT_PIN_AIN(4), + AD4170_CURRENT_SRC_I_OUT_PIN_AIN(5), + AD4170_CURRENT_SRC_I_OUT_PIN_AIN(6), + AD4170_CURRENT_SRC_I_OUT_PIN_AIN(7), + AD4170_CURRENT_SRC_I_OUT_PIN_AIN(8), + AD4170_CURRENT_SRC_I_OUT_PIN_GPIO(0), + AD4170_CURRENT_SRC_I_OUT_PIN_GPIO(1), + AD4170_CURRENT_SRC_I_OUT_PIN_GPIO(2), + AD4170_CURRENT_SRC_I_OUT_PIN_GPIO(3), +}; + +static const unsigned int ad4170_iout_current_ua_tbl[] = { + 0, 10, 50, 100, 250, 500, 1000, 1500, +}; + +enum ad4170_sensor_enum { + AD4170_ADC_SENSOR = 0, + AD4170_WEIGH_SCALE_SENSOR = 1, + AD4170_RTD_SENSOR = 2, + AD4170_THERMOCOUPLE_SENSOR = 3, +}; + +/* maps adi,sensor-type property value to enum */ +static const char * const ad4170_sensor_type[] = { + [AD4170_ADC_SENSOR] = "adc", + [AD4170_WEIGH_SCALE_SENSOR] = "weighscale", + [AD4170_RTD_SENSOR] = "rtd", + [AD4170_THERMOCOUPLE_SENSOR] = "thermocouple", +}; + +struct ad4170_chip_info { + const char *name; +}; + +static const struct ad4170_chip_info ad4170_chip_info = { + .name = "ad4170-4", +}; + +static const struct ad4170_chip_info ad4190_chip_info = { + .name = "ad4190-4", +}; + +static const struct ad4170_chip_info ad4195_chip_info = { + .name = "ad4195-4", +}; + +/* + * There are 8 of each MISC, AFE, FILTER, FILTER_FS, OFFSET, and GAIN + * configuration registers. That is, there are 8 miscellaneous registers, MISC0 + * to MISC7. Each MISC register is associated with a setup; MISCN is associated + * with setup number N. The other 5 above mentioned types of registers have + * analogous structure. A setup is a set of those registers. For example, + * setup 1 comprises of MISC1, AFE1, FILTER1, FILTER_FS1, OFFSET1, and GAIN1 + * registers. Also, there are 16 CHANNEL_SETUP registers (CHANNEL_SETUP0 to + * CHANNEL_SETUP15). Each channel setup is associated with one of the 8 possible + * setups. Thus, AD4170 can support up to 16 channels but, since there are only + * 8 available setups, channels must share settings if more than 8 channels are + * configured. + * + * If this struct is modified, ad4170_setup_eq() will probably need to be + * updated too. + */ +struct ad4170_setup { + u16 misc; + u16 afe; + u16 filter; + u16 filter_fs; + u32 offset; /* For calibration purposes */ + u32 gain; /* For calibration purposes */ +}; + +struct ad4170_setup_info { + struct ad4170_setup setup; + unsigned int enabled_channels; + unsigned int channels; +}; + +struct ad4170_chan_info { + unsigned int input_range_uv; + unsigned int setup_num; /* Index to access state setup_infos array */ + struct ad4170_setup setup; /* cached setup */ + int offset_tbl[10]; + u32 scale_tbl[10][2]; + bool initialized; + bool enabled; +}; + +static const char * const ad4170_filt_names[] = { + [AD4170_SINC5_AVG] = "sinc5+avg", + [AD4170_SINC5] = "sinc5", + [AD4170_SINC3] = "sinc3", +}; + +struct ad4170_state { + struct mutex lock; /* Protect read-modify-write and multi write sequences */ + int vrefs_uv[AD4170_MAX_SUP]; + u32 mclk_hz; + struct ad4170_setup_info setup_infos[AD4170_MAX_SETUPS]; + struct ad4170_chan_info chan_infos[AD4170_MAX_ADC_CHANNELS]; + struct completion completion; + struct iio_chan_spec chans[AD4170_MAX_IIO_CHANNELS]; + struct spi_device *spi; + struct regmap *regmap; + int sps_tbl[ARRAY_SIZE(ad4170_filt_names)][AD4170_MAX_FS_TBL_SIZE][2]; + __be32 bounce_buffer[AD4170_MAX_ADC_CHANNELS]; + struct spi_message msg; + struct spi_transfer xfer; + struct iio_trigger *trig; + struct clk_hw int_clk_hw; + unsigned int clock_ctrl; + unsigned int pins_fn[AD4170_NUM_ANALOG_PINS]; + int gpio_fn[AD4170_NUM_GPIO_PINS]; + unsigned int cur_src_pins[AD4170_NUM_CURRENT_SRC]; + struct gpio_chip gpiochip; + /* + * DMA (thus cache coherency maintenance) requires the transfer buffers + * to live in their own cache lines. + */ + u8 rx_buf[4] __aligned(IIO_DMA_MINALIGN); +}; + +static void ad4170_fill_sps_tbl(struct ad4170_state *st) +{ + unsigned int tmp0, tmp1, i; + + /* + * The ODR can be calculated the same way for sinc5+avg, sinc5, and + * sinc3 filter types with the exception that sinc5 filter has a + * narrowed range of allowed FILTER_FS values. + */ + for (i = 0; i < ARRAY_SIZE(ad4170_sinc3_filt_fs_tbl); i++) { + tmp0 = div_u64_rem(st->mclk_hz, 32 * ad4170_sinc3_filt_fs_tbl[i], + &tmp1); + tmp1 = mult_frac(tmp1, MICRO, 32 * ad4170_sinc3_filt_fs_tbl[i]); + /* Fill sinc5+avg filter SPS table */ + st->sps_tbl[AD4170_SINC5_AVG][i][0] = tmp0; /* Integer part */ + st->sps_tbl[AD4170_SINC5_AVG][i][1] = tmp1; /* Fractional part */ + + /* Fill sinc3 filter SPS table */ + st->sps_tbl[AD4170_SINC3][i][0] = tmp0; /* Integer part */ + st->sps_tbl[AD4170_SINC3][i][1] = tmp1; /* Fractional part */ + } + /* Sinc5 filter ODR doesn't use all FILTER_FS bits */ + for (i = 0; i < ARRAY_SIZE(ad4170_sinc5_filt_fs_tbl); i++) { + tmp0 = div_u64_rem(st->mclk_hz, 32 * ad4170_sinc5_filt_fs_tbl[i], + &tmp1); + tmp1 = mult_frac(tmp1, MICRO, 32 * ad4170_sinc5_filt_fs_tbl[i]); + /* Fill sinc5 filter SPS table */ + st->sps_tbl[AD4170_SINC5][i][0] = tmp0; /* Integer part */ + st->sps_tbl[AD4170_SINC5][i][1] = tmp1; /* Fractional part */ + } +} + +static int ad4170_debugfs_reg_access(struct iio_dev *indio_dev, + unsigned int reg, unsigned int writeval, + unsigned int *readval) +{ + struct ad4170_state *st = iio_priv(indio_dev); + + if (readval) + return regmap_read(st->regmap, reg, readval); + + return regmap_write(st->regmap, reg, writeval); +} + +static int ad4170_get_reg_size(struct ad4170_state *st, unsigned int reg, + unsigned int *size) +{ + if (reg >= ARRAY_SIZE(ad4170_reg_size)) + return -EINVAL; + + *size = ad4170_reg_size[reg]; + + return 0; +} + +static int ad4170_reg_write(void *context, unsigned int reg, unsigned int val) +{ + struct ad4170_state *st = context; + u8 tx_buf[AD4170_SPI_MAX_XFER_LEN]; + unsigned int size; + int ret; + + ret = ad4170_get_reg_size(st, reg, &size); + if (ret) + return ret; + + put_unaligned_be16(reg, tx_buf); + switch (size) { + case 3: + put_unaligned_be24(val, &tx_buf[AD4170_SPI_INST_PHASE_LEN]); + break; + case 2: + put_unaligned_be16(val, &tx_buf[AD4170_SPI_INST_PHASE_LEN]); + break; + case 1: + tx_buf[AD4170_SPI_INST_PHASE_LEN] = val; + break; + case 0: + /* Write continuous read exit code */ + tx_buf[0] = AD4170_ADC_CTRL_CONT_READ_EXIT; + return spi_write_then_read(st->spi, tx_buf, 1, NULL, 0); + default: + return -EINVAL; + } + + return spi_write_then_read(st->spi, tx_buf, + AD4170_SPI_INST_PHASE_LEN + size, NULL, 0); +} + +static int ad4170_reg_read(void *context, unsigned int reg, unsigned int *val) +{ + struct ad4170_state *st = context; + u8 tx_buf[AD4170_SPI_INST_PHASE_LEN]; + unsigned int size; + int ret; + + put_unaligned_be16(AD4170_REG_READ_MASK | reg, tx_buf); + + ret = ad4170_get_reg_size(st, reg, &size); + if (ret) + return ret; + + ret = spi_write_then_read(st->spi, tx_buf, ARRAY_SIZE(tx_buf), + st->rx_buf, size); + if (ret) + return ret; + + switch (size) { + case 3: + *val = get_unaligned_be24(st->rx_buf); + return 0; + case 2: + *val = get_unaligned_be16(st->rx_buf); + return 0; + case 1: + *val = st->rx_buf[0]; + return 0; + default: + return -EINVAL; + } +} + +static const struct regmap_config ad4170_regmap_config = { + .reg_read = ad4170_reg_read, + .reg_write = ad4170_reg_write, +}; + +static bool ad4170_setup_eq(struct ad4170_setup *a, struct ad4170_setup *b) +{ + if (a->misc != b->misc || + a->afe != b->afe || + a->filter != b->filter || + a->filter_fs != b->filter_fs || + a->offset != b->offset || + a->gain != b->gain) + return false; + + return true; +} + +static int ad4170_find_setup(struct ad4170_state *st, + struct ad4170_setup *target_setup, + unsigned int *setup_num, bool *overwrite) +{ + unsigned int i; + + *setup_num = AD4170_INVALID_SETUP; + *overwrite = false; + + for (i = 0; i < AD4170_MAX_SETUPS; i++) { + struct ad4170_setup_info *setup_info = &st->setup_infos[i]; + + /* Immediately accept a matching setup. */ + if (ad4170_setup_eq(target_setup, &setup_info->setup)) { + *setup_num = i; + return 0; + } + + /* Ignore all setups which are used by enabled channels. */ + if (setup_info->enabled_channels) + continue; + + /* Find the least used slot. */ + if (*setup_num == AD4170_INVALID_SETUP || + setup_info->channels < st->setup_infos[*setup_num].channels) + *setup_num = i; + } + + if (*setup_num == AD4170_INVALID_SETUP) + return -EINVAL; + + *overwrite = true; + return 0; +} + +static void ad4170_unlink_channel(struct ad4170_state *st, unsigned int channel) +{ + struct ad4170_chan_info *chan_info = &st->chan_infos[channel]; + struct ad4170_setup_info *setup_info = &st->setup_infos[chan_info->setup_num]; + + chan_info->setup_num = AD4170_INVALID_SETUP; + setup_info->channels--; +} + +static int ad4170_unlink_setup(struct ad4170_state *st, unsigned int setup_num) +{ + unsigned int i; + + for (i = 0; i < AD4170_MAX_ADC_CHANNELS; i++) { + struct ad4170_chan_info *chan_info = &st->chan_infos[i]; + + if (!chan_info->initialized || chan_info->setup_num != setup_num) + continue; + + ad4170_unlink_channel(st, i); + } + return 0; +} + +static int ad4170_link_channel_setup(struct ad4170_state *st, + unsigned int chan_addr, + unsigned int setup_num) +{ + struct ad4170_setup_info *setup_info = &st->setup_infos[setup_num]; + struct ad4170_chan_info *chan_info = &st->chan_infos[chan_addr]; + int ret; + + ret = regmap_update_bits(st->regmap, AD4170_CHAN_SETUP_REG(chan_addr), + AD4170_CHAN_SETUP_SETUP_MSK, + FIELD_PREP(AD4170_CHAN_SETUP_SETUP_MSK, setup_num)); + if (ret) + return ret; + + chan_info->setup_num = setup_num; + setup_info->channels++; + return 0; +} + +static int ad4170_write_setup(struct ad4170_state *st, unsigned int setup_num, + struct ad4170_setup *setup) +{ + int ret; + + /* + * It is recommended to place the ADC in standby mode or idle mode to + * write to OFFSET and GAIN registers. + */ + ret = regmap_update_bits(st->regmap, AD4170_ADC_CTRL_REG, + AD4170_ADC_CTRL_MODE_MSK, + FIELD_PREP(AD4170_ADC_CTRL_MODE_MSK, + AD4170_ADC_CTRL_MODE_IDLE)); + if (ret) + return ret; + + ret = regmap_write(st->regmap, AD4170_MISC_REG(setup_num), setup->misc); + if (ret) + return ret; + + ret = regmap_write(st->regmap, AD4170_AFE_REG(setup_num), setup->afe); + if (ret) + return ret; + + ret = regmap_write(st->regmap, AD4170_FILTER_REG(setup_num), + setup->filter); + if (ret) + return ret; + + ret = regmap_write(st->regmap, AD4170_FILTER_FS_REG(setup_num), + setup->filter_fs); + if (ret) + return ret; + + ret = regmap_write(st->regmap, AD4170_OFFSET_REG(setup_num), + setup->offset); + if (ret) + return ret; + + ret = regmap_write(st->regmap, AD4170_GAIN_REG(setup_num), setup->gain); + if (ret) + return ret; + + memcpy(&st->setup_infos[setup_num].setup, setup, sizeof(*setup)); + return 0; +} + +static int ad4170_write_channel_setup(struct ad4170_state *st, + unsigned int chan_addr, bool on_enable) +{ + struct ad4170_chan_info *chan_info = &st->chan_infos[chan_addr]; + bool overwrite; + int setup_num; + int ret; + + /* + * Similar to AD4130 driver, the following cases need to be handled. + * + * 1. Enabled and linked channel with setup changes: + * - Find a setup. If not possible, return error. + * - Unlink channel from current setup. + * - If the setup found has only disabled channels linked to it, + * unlink all channels, and write the new setup to it. + * - Link channel to new setup. + * + * 2. Soon to be enabled and unlinked channel: + * - Find a setup. If not possible, return error. + * - If the setup found has only disabled channels linked to it, + * unlink all channels, and write the new setup to it. + * - Link channel to the setup. + * + * 3. Disabled and linked channel with setup changes: + * - Unlink channel from current setup. + * + * 4. Soon to be enabled and linked channel: + * 5. Disabled and unlinked channel with setup changes: + * - Do nothing. + */ + + /* Cases 3, 4, and 5 */ + if (chan_info->setup_num != AD4170_INVALID_SETUP) { + /* Case 4 */ + if (on_enable) + return 0; + + /* Case 3 */ + if (!chan_info->enabled) { + ad4170_unlink_channel(st, chan_addr); + return 0; + } + } else if (!on_enable && !chan_info->enabled) { + /* Case 5 */ + return 0; + } + + /* Cases 1 & 2 */ + ret = ad4170_find_setup(st, &chan_info->setup, &setup_num, &overwrite); + if (ret) + return ret; + + if (chan_info->setup_num != AD4170_INVALID_SETUP) + /* Case 1 */ + ad4170_unlink_channel(st, chan_addr); + + if (overwrite) { + ret = ad4170_unlink_setup(st, setup_num); + if (ret) + return ret; + + ret = ad4170_write_setup(st, setup_num, &chan_info->setup); + if (ret) + return ret; + } + + return ad4170_link_channel_setup(st, chan_addr, setup_num); +} + +static int ad4170_set_channel_enable(struct ad4170_state *st, + unsigned int chan_addr, bool status) +{ + struct ad4170_chan_info *chan_info = &st->chan_infos[chan_addr]; + struct ad4170_setup_info *setup_info; + int ret; + + if (chan_info->enabled == status) + return 0; + + if (status) { + ret = ad4170_write_channel_setup(st, chan_addr, true); + if (ret) + return ret; + } + + setup_info = &st->setup_infos[chan_info->setup_num]; + + ret = regmap_update_bits(st->regmap, AD4170_CHAN_EN_REG, + AD4170_CHAN_EN(chan_addr), + status ? AD4170_CHAN_EN(chan_addr) : 0); + if (ret) + return ret; + + setup_info->enabled_channels += status ? 1 : -1; + chan_info->enabled = status; + return 0; +} + +static int __ad4170_get_filter_type(unsigned int filter) +{ + u16 f_conf = FIELD_GET(AD4170_FILTER_FILTER_TYPE_MSK, filter); + + switch (f_conf) { + case AD4170_FILTER_FILTER_TYPE_SINC5_AVG: + return AD4170_SINC5_AVG; + case AD4170_FILTER_FILTER_TYPE_SINC5: + return AD4170_SINC5; + case AD4170_FILTER_FILTER_TYPE_SINC3: + return AD4170_SINC3; + default: + return -EINVAL; + } +} + +static int ad4170_set_filter_type(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + unsigned int val) +{ + struct ad4170_state *st = iio_priv(indio_dev); + struct ad4170_chan_info *chan_info = &st->chan_infos[chan->address]; + struct ad4170_setup *setup = &chan_info->setup; + unsigned int filter_type_conf; + int ret; + + switch (val) { + case AD4170_SINC5_AVG: + filter_type_conf = AD4170_FILTER_FILTER_TYPE_SINC5_AVG; + break; + case AD4170_SINC5: + filter_type_conf = AD4170_FILTER_FILTER_TYPE_SINC5; + break; + case AD4170_SINC3: + filter_type_conf = AD4170_FILTER_FILTER_TYPE_SINC3; + break; + default: + return -EINVAL; + } + + /* + * The filters provide the same ODR for a given filter_fs value but + * there are different minimum and maximum filter_fs limits for each + * filter. The filter_fs value will be adjusted if the current filter_fs + * is out of the limits of the just requested filter. Since the + * filter_fs value affects the ODR (sampling_frequency), changing the + * filter may lead to a change in the sampling frequency. + */ + scoped_guard(mutex, &st->lock) { + if (!iio_device_claim_direct(indio_dev)) + return -EBUSY; + + if (val == AD4170_SINC5_AVG || val == AD4170_SINC3) + setup->filter_fs = clamp(val, AD4170_SINC3_MIN_FS, + AD4170_SINC3_MAX_FS); + else + setup->filter_fs = clamp(val, AD4170_SINC5_MIN_FS, + AD4170_SINC5_MAX_FS); + + setup->filter &= ~AD4170_FILTER_FILTER_TYPE_MSK; + setup->filter |= FIELD_PREP(AD4170_FILTER_FILTER_TYPE_MSK, + filter_type_conf); + + ret = ad4170_write_channel_setup(st, chan->address, false); + iio_device_release_direct(indio_dev); + } + + return ret; +} + +static int ad4170_get_filter_type(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan) +{ + struct ad4170_state *st = iio_priv(indio_dev); + struct ad4170_chan_info *chan_info = &st->chan_infos[chan->address]; + struct ad4170_setup *setup = &chan_info->setup; + + return __ad4170_get_filter_type(setup->filter); +} + +static const struct iio_enum ad4170_filter_type_enum = { + .items = ad4170_filt_names, + .num_items = ARRAY_SIZE(ad4170_filt_names), + .get = ad4170_get_filter_type, + .set = ad4170_set_filter_type, +}; + +static const struct iio_chan_spec_ext_info ad4170_filter_type_ext_info[] = { + IIO_ENUM("filter_type", IIO_SEPARATE, &ad4170_filter_type_enum), + IIO_ENUM_AVAILABLE("filter_type", IIO_SHARED_BY_TYPE, + &ad4170_filter_type_enum), + { } +}; + +static const struct iio_chan_spec ad4170_channel_template = { + .type = IIO_VOLTAGE, + .indexed = 1, + .differential = 1, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE) | + BIT(IIO_CHAN_INFO_CALIBBIAS) | + BIT(IIO_CHAN_INFO_CALIBSCALE) | + BIT(IIO_CHAN_INFO_SAMP_FREQ) | + BIT(IIO_CHAN_INFO_OFFSET), + .info_mask_separate_available = BIT(IIO_CHAN_INFO_SCALE) | + BIT(IIO_CHAN_INFO_SAMP_FREQ), + .ext_info = ad4170_filter_type_ext_info, + .scan_type = { + .realbits = 24, + .storagebits = 32, + .shift = 8, + .endianness = IIO_BE, + }, +}; + +static const struct iio_chan_spec ad4170_temp_channel_template = { + .type = IIO_TEMP, + .indexed = 0, + .channel = 17, + .channel2 = 17, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE) | + BIT(IIO_CHAN_INFO_OFFSET) | + BIT(IIO_CHAN_INFO_CALIBSCALE) | + BIT(IIO_CHAN_INFO_CALIBBIAS) | + BIT(IIO_CHAN_INFO_SAMP_FREQ), + .info_mask_separate_available = BIT(IIO_CHAN_INFO_SAMP_FREQ), + .scan_type = { + .sign = 's', + .realbits = 24, + .storagebits = 32, + .shift = 8, + .endianness = IIO_BE, + }, +}; + +/* + * Receives the number of a multiplexed AD4170 input (ain_n), and stores the + * voltage (in µV) of the specified input into ain_voltage. If the input number + * is a ordinary analog input (AIN0 to AIN8), stores zero into ain_voltage. + * If a voltage regulator required by a special input is unavailable, return + * error code. Return 0 on success. + */ +static int ad4170_get_ain_voltage_uv(struct ad4170_state *st, int ain_n, + int *ain_voltage) +{ + struct device *dev = &st->spi->dev; + int v_diff; + + *ain_voltage = 0; + /* + * The voltage bias (vbias) sets the common-mode voltage of the channel + * to (AVDD + AVSS)/2. If provided, AVSS supply provides the magnitude + * (absolute value) of the negative voltage supplied to the AVSS pin. + * So, we do AVDD - AVSS to compute the DC voltage generated by the bias + * voltage generator. + */ + if (st->pins_fn[ain_n] & AD4170_PIN_VBIAS) { + int v_diff = st->vrefs_uv[AD4170_AVDD_SUP] - st->vrefs_uv[AD4170_AVSS_SUP]; + *ain_voltage = v_diff / 2; + return 0; + } + + if (ain_n <= AD4170_CHAN_MAP_TEMP_SENSOR) + return 0; + + switch (ain_n) { + case AD4170_CHAN_MAP_AVDD_AVSS_N: + v_diff = st->vrefs_uv[AD4170_AVDD_SUP] - st->vrefs_uv[AD4170_AVSS_SUP]; + *ain_voltage = v_diff / 5; + return 0; + case AD4170_CHAN_MAP_IOVDD_DGND_N: + *ain_voltage = st->vrefs_uv[AD4170_IOVDD_SUP] / 5; + return 0; + case AD4170_CHAN_MAP_AVSS: + *ain_voltage = st->vrefs_uv[AD4170_AVSS_SUP]; + return 0; + case AD4170_CHAN_MAP_DGND: + *ain_voltage = 0; + return 0; + case AD4170_CHAN_MAP_REFIN1_P: + if (st->vrefs_uv[AD4170_REFIN1P_SUP] == -ENODEV) + return dev_err_probe(dev, -ENODEV, + "input set to REFIN+ but ref not provided\n"); + + *ain_voltage = st->vrefs_uv[AD4170_REFIN1P_SUP]; + return 0; + case AD4170_CHAN_MAP_REFIN1_N: + if (st->vrefs_uv[AD4170_REFIN1N_SUP] == -ENODEV) + return dev_err_probe(dev, -ENODEV, + "input set to REFIN- but ref not provided\n"); + + *ain_voltage = st->vrefs_uv[AD4170_REFIN1N_SUP]; + return 0; + case AD4170_CHAN_MAP_REFIN2_P: + if (st->vrefs_uv[AD4170_REFIN2P_SUP] == -ENODEV) + return dev_err_probe(dev, -ENODEV, + "input set to REFIN2+ but ref not provided\n"); + + *ain_voltage = st->vrefs_uv[AD4170_REFIN2P_SUP]; + return 0; + case AD4170_CHAN_MAP_REFIN2_N: + if (st->vrefs_uv[AD4170_REFIN2N_SUP] == -ENODEV) + return dev_err_probe(dev, -ENODEV, + "input set to REFIN2- but ref not provided\n"); + + *ain_voltage = st->vrefs_uv[AD4170_REFIN2N_SUP]; + return 0; + case AD4170_CHAN_MAP_REFOUT: + /* REFOUT is 2.5V relative to AVSS so take that into account */ + *ain_voltage = st->vrefs_uv[AD4170_AVSS_SUP] + AD4170_INT_REF_2_5V; + return 0; + default: + return -EINVAL; + } +} + +static int ad4170_validate_analog_input(struct ad4170_state *st, int pin) +{ + if (pin <= AD4170_MAX_ANALOG_PINS) { + if (st->pins_fn[pin] & AD4170_PIN_CURRENT_OUT) + return dev_err_probe(&st->spi->dev, -EINVAL, + "Pin %d already used with fn %u.\n", + pin, st->pins_fn[pin]); + + st->pins_fn[pin] |= AD4170_PIN_ANALOG_IN; + } + return 0; +} + +static int ad4170_validate_channel_input(struct ad4170_state *st, int pin, bool com) +{ + /* Check common-mode input pin is mapped to a special input. */ + if (com && (pin < AD4170_CHAN_MAP_AVDD_AVSS_P || pin > AD4170_CHAN_MAP_REFOUT)) + return dev_err_probe(&st->spi->dev, -EINVAL, + "Invalid common-mode input pin number. %d\n", + pin); + + /* Check differential input pin is mapped to a analog input pin. */ + if (!com && pin > AD4170_MAX_ANALOG_PINS) + return dev_err_probe(&st->spi->dev, -EINVAL, + "Invalid analog input pin number. %d\n", + pin); + + return ad4170_validate_analog_input(st, pin); +} + +/* + * Verifies whether the channel input configuration is valid by checking the + * input numbers. + * Returns 0 on valid channel input configuration. -EINVAL otherwise. + */ +static int ad4170_validate_channel(struct ad4170_state *st, + struct iio_chan_spec const *chan) +{ + int ret; + + ret = ad4170_validate_channel_input(st, chan->channel, false); + if (ret) + return ret; + + return ad4170_validate_channel_input(st, chan->channel2, + !chan->differential); +} + +/* + * Verifies whether the channel configuration is valid by checking the provided + * input type, polarity, and voltage references result in a sane input range. + * Returns negative error code on failure. + */ +static int ad4170_get_input_range(struct ad4170_state *st, + struct iio_chan_spec const *chan, + unsigned int ch_reg, unsigned int ref_sel) +{ + bool bipolar = chan->scan_type.sign == 's'; + struct device *dev = &st->spi->dev; + int refp, refn, ain_voltage, ret; + + switch (ref_sel) { + case AD4170_REF_REFIN1: + if (st->vrefs_uv[AD4170_REFIN1P_SUP] == -ENODEV || + st->vrefs_uv[AD4170_REFIN1N_SUP] == -ENODEV) + return dev_err_probe(dev, -ENODEV, + "REFIN± selected but not provided\n"); + + refp = st->vrefs_uv[AD4170_REFIN1P_SUP]; + refn = st->vrefs_uv[AD4170_REFIN1N_SUP]; + break; + case AD4170_REF_REFIN2: + if (st->vrefs_uv[AD4170_REFIN2P_SUP] == -ENODEV || + st->vrefs_uv[AD4170_REFIN2N_SUP] == -ENODEV) + return dev_err_probe(dev, -ENODEV, + "REFIN2± selected but not provided\n"); + + refp = st->vrefs_uv[AD4170_REFIN2P_SUP]; + refn = st->vrefs_uv[AD4170_REFIN2N_SUP]; + break; + case AD4170_REF_AVDD: + refp = st->vrefs_uv[AD4170_AVDD_SUP]; + refn = st->vrefs_uv[AD4170_AVSS_SUP]; + break; + case AD4170_REF_REFOUT: + /* REFOUT is 2.5 V relative to AVSS */ + refp = st->vrefs_uv[AD4170_AVSS_SUP] + AD4170_INT_REF_2_5V; + refn = st->vrefs_uv[AD4170_AVSS_SUP]; + break; + default: + return -EINVAL; + } + + /* + * Find out the analog input range from the channel type, polarity, and + * voltage reference selection. + * AD4170 channels are either differential or pseudo-differential. + * Diff input voltage range: −VREF/gain to +VREF/gain (datasheet page 6) + * Pseudo-diff input voltage range: 0 to VREF/gain (datasheet page 6) + */ + if (chan->differential) { + if (!bipolar) + return dev_err_probe(dev, -EINVAL, + "Channel %u differential unipolar\n", + ch_reg); + + /* + * Differential bipolar channel. + * avss-supply is never above 0V. + * Assuming refin1n-supply not above 0V. + * Assuming refin2n-supply not above 0V. + */ + return refp + abs(refn); + } + /* + * Some configurations can lead to invalid setups. + * For example, if AVSS = -2.5V, REF_SELECT set to REFOUT (REFOUT/AVSS), + * and pseudo-diff channel configuration set, then the input range + * should go from 0V to +VREF (single-ended - datasheet pg 10), but + * REFOUT/AVSS range would be -2.5V to 0V. + * Check the positive reference is higher than 0V for pseudo-diff + * channels. + * Note that at this point in the code, refp can only be >= 0 since all + * error codes from reading the regulator voltage have been checked + * either at ad4170_regulator_setup() or above in this function. + */ + if (refp == 0) + return dev_err_probe(dev, -EINVAL, + "REF+ == GND for pseudo-diff chan %u\n", + ch_reg); + + if (bipolar) + return refp; + + /* + * Pseudo-differential unipolar channel. + * Input expected to swing from IN- to +VREF. + */ + ret = ad4170_get_ain_voltage_uv(st, chan->channel2, &ain_voltage); + if (ret) + return ret; + + if (refp - ain_voltage <= 0) + return dev_err_probe(dev, -EINVAL, + "Negative input >= REF+ for pseudo-diff chan %u\n", + ch_reg); + + return refp - ain_voltage; +} + +static int __ad4170_read_sample(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, int *val) +{ + struct ad4170_state *st = iio_priv(indio_dev); + unsigned long settling_time_ms; + int ret; + + reinit_completion(&st->completion); + ret = regmap_update_bits(st->regmap, AD4170_ADC_CTRL_REG, + AD4170_ADC_CTRL_MODE_MSK, + FIELD_PREP(AD4170_ADC_CTRL_MODE_MSK, + AD4170_ADC_CTRL_MODE_SINGLE)); + if (ret) + return ret; + + /* + * When a channel is manually selected by the user, the ADC needs an + * extra time to provide the first stable conversion. The ADC settling + * time depends on the filter type, filter frequency, and ADC clock + * frequency (see datasheet page 53). The maximum settling time among + * all filter configurations is 6291164 / fCLK. Use that formula to wait + * for sufficient time whatever the filter configuration may be. + */ + settling_time_ms = DIV_ROUND_UP(6291164 * MILLI, st->mclk_hz); + ret = wait_for_completion_timeout(&st->completion, + msecs_to_jiffies(settling_time_ms)); + if (!ret) + dev_dbg(&st->spi->dev, + "No Data Ready signal. Reading after delay.\n"); + + ret = regmap_read(st->regmap, AD4170_DATA_24B_REG, val); + if (ret) + return ret; + + if (chan->scan_type.sign == 's') + *val = sign_extend32(*val, chan->scan_type.realbits - 1); + + return 0; +} + +static int ad4170_read_sample(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, int *val) +{ + struct ad4170_state *st = iio_priv(indio_dev); + struct device *dev = &st->spi->dev; + int ret, ret2; + + /* + * The ADC sequences through all enabled channels. That can lead to + * incorrect channel being sampled if a previous read would have left a + * different channel enabled. Thus, always enable and disable the + * channel on single-shot read. + */ + ret = ad4170_set_channel_enable(st, chan->address, true); + if (ret) + return ret; + + ret = __ad4170_read_sample(indio_dev, chan, val); + if (ret) { + dev_err(dev, "failed to read sample: %d\n", ret); + + ret2 = ad4170_set_channel_enable(st, chan->address, false); + if (ret2) + dev_err(dev, "failed to disable channel: %d\n", ret2); + + return ret; + } + + ret = ad4170_set_channel_enable(st, chan->address, false); + if (ret) + return ret; + + return IIO_VAL_INT; +} + +static int ad4170_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long info) +{ + struct ad4170_state *st = iio_priv(indio_dev); + struct ad4170_chan_info *chan_info = &st->chan_infos[chan->address]; + struct ad4170_setup *setup = &chan_info->setup; + enum ad4170_filter_type f_type; + unsigned int pga, fs_idx; + int ret; + + guard(mutex)(&st->lock); + switch (info) { + case IIO_CHAN_INFO_RAW: + if (!iio_device_claim_direct(indio_dev)) + return -EBUSY; + + ret = ad4170_read_sample(indio_dev, chan, val); + iio_device_release_direct(indio_dev); + return ret; + case IIO_CHAN_INFO_SCALE: + pga = FIELD_GET(AD4170_AFE_PGA_GAIN_MSK, setup->afe); + switch (chan->type) { + case IIO_VOLTAGE: + *val = chan_info->scale_tbl[pga][0]; + *val2 = chan_info->scale_tbl[pga][1]; + return IIO_VAL_INT_PLUS_NANO; + case IIO_TEMP: + /* + * The scale_tbl converts output codes to mV units so + * multiply by MILLI to make the factor convert to µV. + * Then, apply the temperature sensor change sensitivity + * of 477 μV/K. Finally, multiply the result by MILLI + * again to comply with milli degrees Celsius IIO ABI. + */ + *val = 0; + *val2 = DIV_ROUND_CLOSEST(chan_info->scale_tbl[pga][1] * MILLI, 477) * + MILLI; + return IIO_VAL_INT_PLUS_NANO; + default: + return -EINVAL; + } + case IIO_CHAN_INFO_OFFSET: + pga = FIELD_GET(AD4170_AFE_PGA_GAIN_MSK, setup->afe); + *val = chan_info->offset_tbl[pga]; + return IIO_VAL_INT; + case IIO_CHAN_INFO_SAMP_FREQ: + f_type = __ad4170_get_filter_type(setup->filter); + switch (f_type) { + case AD4170_SINC5_AVG: + case AD4170_SINC3: + fs_idx = find_closest(setup->filter_fs, + ad4170_sinc3_filt_fs_tbl, + ARRAY_SIZE(ad4170_sinc3_filt_fs_tbl)); + *val = st->sps_tbl[f_type][fs_idx][0]; + *val2 = st->sps_tbl[f_type][fs_idx][1]; + return IIO_VAL_INT_PLUS_MICRO; + case AD4170_SINC5: + fs_idx = find_closest(setup->filter_fs, + ad4170_sinc5_filt_fs_tbl, + ARRAY_SIZE(ad4170_sinc5_filt_fs_tbl)); + *val = st->sps_tbl[f_type][fs_idx][0]; + *val2 = st->sps_tbl[f_type][fs_idx][1]; + return IIO_VAL_INT_PLUS_MICRO; + default: + return -EINVAL; + } + case IIO_CHAN_INFO_CALIBBIAS: + *val = setup->offset; + return IIO_VAL_INT; + case IIO_CHAN_INFO_CALIBSCALE: + *val = setup->gain; + return IIO_VAL_INT; + default: + return -EINVAL; + } +} + +static int ad4170_fill_scale_tbl(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan) +{ + struct ad4170_state *st = iio_priv(indio_dev); + struct ad4170_chan_info *chan_info = &st->chan_infos[chan->address]; + struct device *dev = &st->spi->dev; + int bipolar = chan->scan_type.sign == 's' ? 1 : 0; + int precision_bits = chan->scan_type.realbits; + int pga, ainm_voltage, ret; + unsigned long long offset; + + ainm_voltage = 0; + ret = ad4170_get_ain_voltage_uv(st, chan->channel2, &ainm_voltage); + if (ret < 0) + return dev_err_probe(dev, ret, "Failed to fill scale table\n"); + + for (pga = 0; pga < AD4170_NUM_PGA_OPTIONS; pga++) { + u64 nv; + unsigned int lshift, rshift; + + /* + * The PGA options are numbered from 0 to 9, with option 0 being + * a gain of 2^0 (no actual gain), and 7 meaning a gain of 2^7. + * Option 8, though, sets a gain of 0.5, so the input signal can + * be attenuated by 2 rather than amplified. Option 9, allows + * the signal to bypass the PGA circuitry (no gain). + * + * The scale factor to get ADC output codes to values in mV + * units is given by: + * _scale = (input_range / gain) / 2^precision + * AD4170 gain is a power of 2 so the above can be written as + * _scale = input_range / 2^(precision + gain) + * Keep the input range in µV to avoid truncating the less + * significant bits when right shifting it so to preserve scale + * precision. + */ + nv = (u64)chan_info->input_range_uv * NANO; + lshift = !!(pga & BIT(3)); /* handle PGA options 8 and 9 */ + rshift = precision_bits - bipolar + (pga & GENMASK(2, 0)) - lshift; + chan_info->scale_tbl[pga][0] = 0; + chan_info->scale_tbl[pga][1] = div_u64(nv >> rshift, MILLI); + + /* + * If the negative input is not at GND, the conversion result + * (which is relative to IN-) will be offset by the level at IN-. + * Use the scale factor the other way around to go from a known + * voltage to the corresponding ADC output code. + * With that, we are able to get to what would be the output + * code for the voltage at the negative input. + * If the negative input is not fixed, there is no offset. + */ + offset = ((unsigned long long)abs(ainm_voltage)) * MICRO; + offset = DIV_ROUND_CLOSEST_ULL(offset, chan_info->scale_tbl[pga][1]); + + /* + * After divided by the scale, offset will always fit into 31 + * bits. For _raw + _offset to be relative to GND, the value + * provided as _offset is of opposite sign than the real offset. + */ + if (ainm_voltage > 0) + chan_info->offset_tbl[pga] = -(int)(offset); + else + chan_info->offset_tbl[pga] = (int)(offset); + } + return 0; +} + +static int ad4170_read_avail(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + const int **vals, int *type, int *length, + long info) +{ + struct ad4170_state *st = iio_priv(indio_dev); + struct ad4170_chan_info *chan_info = &st->chan_infos[chan->address]; + enum ad4170_filter_type f_type; + + switch (info) { + case IIO_CHAN_INFO_SCALE: + *vals = (int *)chan_info->scale_tbl; + *length = ARRAY_SIZE(chan_info->scale_tbl) * 2; + *type = IIO_VAL_INT_PLUS_NANO; + return IIO_AVAIL_LIST; + case IIO_CHAN_INFO_SAMP_FREQ: + *type = IIO_VAL_INT_PLUS_MICRO; + f_type = ad4170_get_filter_type(indio_dev, chan); + switch (f_type) { + case AD4170_SINC5_AVG: + case AD4170_SINC3: + /* Read sps_tbl here to ensure in bounds array access */ + *vals = (int *)st->sps_tbl[f_type]; + *length = ARRAY_SIZE(ad4170_sinc3_filt_fs_tbl) * 2; + return IIO_AVAIL_LIST; + case AD4170_SINC5: + /* Read sps_tbl here to ensure in bounds array access */ + *vals = (int *)st->sps_tbl[f_type]; + *length = ARRAY_SIZE(ad4170_sinc5_filt_fs_tbl) * 2; + return IIO_AVAIL_LIST; + default: + return -EINVAL; + } + default: + return -EINVAL; + } +} + +static int ad4170_set_pga(struct ad4170_state *st, + struct iio_chan_spec const *chan, int val, int val2) +{ + struct ad4170_chan_info *chan_info = &st->chan_infos[chan->address]; + struct ad4170_setup *setup = &chan_info->setup; + unsigned int pga; + + for (pga = 0; pga < AD4170_NUM_PGA_OPTIONS; pga++) { + if (val == chan_info->scale_tbl[pga][0] && + val2 == chan_info->scale_tbl[pga][1]) + break; + } + + if (pga == AD4170_NUM_PGA_OPTIONS) + return -EINVAL; + + guard(mutex)(&st->lock); + setup->afe &= ~AD4170_AFE_PGA_GAIN_MSK; + setup->afe |= FIELD_PREP(AD4170_AFE_PGA_GAIN_MSK, pga); + + return ad4170_write_channel_setup(st, chan->address, false); +} + +static int ad4170_set_channel_freq(struct ad4170_state *st, + struct iio_chan_spec const *chan, int val, + int val2) +{ + struct ad4170_chan_info *chan_info = &st->chan_infos[chan->address]; + struct ad4170_setup *setup = &chan_info->setup; + enum ad4170_filter_type f_type = __ad4170_get_filter_type(setup->filter); + unsigned int filt_fs_tbl_size, i; + + switch (f_type) { + case AD4170_SINC5_AVG: + case AD4170_SINC3: + filt_fs_tbl_size = ARRAY_SIZE(ad4170_sinc3_filt_fs_tbl); + break; + case AD4170_SINC5: + filt_fs_tbl_size = ARRAY_SIZE(ad4170_sinc5_filt_fs_tbl); + break; + } + + for (i = 0; i < filt_fs_tbl_size; i++) { + if (st->sps_tbl[f_type][i][0] == val && + st->sps_tbl[f_type][i][1] == val2) + break; + } + if (i == filt_fs_tbl_size) + return -EINVAL; + + guard(mutex)(&st->lock); + if (f_type == AD4170_SINC5) + setup->filter_fs = ad4170_sinc5_filt_fs_tbl[i]; + else + setup->filter_fs = ad4170_sinc3_filt_fs_tbl[i]; + + return ad4170_write_channel_setup(st, chan->address, false); +} + +static int ad4170_set_calib_offset(struct ad4170_state *st, + struct iio_chan_spec const *chan, int val) +{ + struct ad4170_chan_info *chan_info = &st->chan_infos[chan->address]; + struct ad4170_setup *setup = &chan_info->setup; + + guard(mutex)(&st->lock); + setup->offset = val; + + return ad4170_write_channel_setup(st, chan->address, false); +} + +static int ad4170_set_calib_gain(struct ad4170_state *st, + struct iio_chan_spec const *chan, int val) +{ + struct ad4170_chan_info *chan_info = &st->chan_infos[chan->address]; + struct ad4170_setup *setup = &chan_info->setup; + + guard(mutex)(&st->lock); + setup->gain = val; + + return ad4170_write_channel_setup(st, chan->address, false); +} + +static int __ad4170_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, int val, + int val2, long info) +{ + struct ad4170_state *st = iio_priv(indio_dev); + + switch (info) { + case IIO_CHAN_INFO_SCALE: + return ad4170_set_pga(st, chan, val, val2); + case IIO_CHAN_INFO_SAMP_FREQ: + return ad4170_set_channel_freq(st, chan, val, val2); + case IIO_CHAN_INFO_CALIBBIAS: + return ad4170_set_calib_offset(st, chan, val); + case IIO_CHAN_INFO_CALIBSCALE: + return ad4170_set_calib_gain(st, chan, val); + default: + return -EINVAL; + } +} + +static int ad4170_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, int val, + int val2, long info) +{ + int ret; + + if (!iio_device_claim_direct(indio_dev)) + return -EBUSY; + + ret = __ad4170_write_raw(indio_dev, chan, val, val2, info); + iio_device_release_direct(indio_dev); + return ret; +} + +static int ad4170_write_raw_get_fmt(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + long info) +{ + switch (info) { + case IIO_CHAN_INFO_SCALE: + return IIO_VAL_INT_PLUS_NANO; + case IIO_CHAN_INFO_SAMP_FREQ: + return IIO_VAL_INT_PLUS_MICRO; + case IIO_CHAN_INFO_CALIBBIAS: + case IIO_CHAN_INFO_CALIBSCALE: + return IIO_VAL_INT; + default: + return -EINVAL; + } +} + +static int ad4170_update_scan_mode(struct iio_dev *indio_dev, + const unsigned long *active_scan_mask) +{ + struct ad4170_state *st = iio_priv(indio_dev); + unsigned int chan_index; + int ret; + + iio_for_each_active_channel(indio_dev, chan_index) { + ret = ad4170_set_channel_enable(st, chan_index, true); + if (ret) + return ret; + } + return 0; +} + +static const struct iio_info ad4170_info = { + .read_raw = ad4170_read_raw, + .read_avail = ad4170_read_avail, + .write_raw = ad4170_write_raw, + .write_raw_get_fmt = ad4170_write_raw_get_fmt, + .update_scan_mode = ad4170_update_scan_mode, + .debugfs_reg_access = ad4170_debugfs_reg_access, +}; + +static int ad4170_soft_reset(struct ad4170_state *st) +{ + int ret; + + ret = regmap_write(st->regmap, AD4170_CONFIG_A_REG, + AD4170_SW_RESET_MSK); + if (ret) + return ret; + + /* AD4170-4 requires 1 ms between reset and any register access. */ + fsleep(1 * USEC_PER_MSEC); + + return 0; +} + +static int ad4170_gpio_get(struct gpio_chip *gc, unsigned int offset) +{ + struct iio_dev *indio_dev = gpiochip_get_data(gc); + struct ad4170_state *st = iio_priv(indio_dev); + unsigned int val; + int ret; + + if (!iio_device_claim_direct(indio_dev)) + return -EBUSY; + + ret = regmap_read(st->regmap, AD4170_GPIO_MODE_REG, &val); + if (ret) + goto err_release; + + /* + * If the GPIO is configured as an input, read the current value from + * AD4170_GPIO_INPUT_REG. Otherwise, read the input value from + * AD4170_GPIO_OUTPUT_REG. + */ + if (val & BIT(offset * 2)) + ret = regmap_read(st->regmap, AD4170_GPIO_INPUT_REG, &val); + else + ret = regmap_read(st->regmap, AD4170_GPIO_OUTPUT_REG, &val); + if (ret) + goto err_release; + + ret = !!(val & BIT(offset)); +err_release: + iio_device_release_direct(indio_dev); + + return ret; +} + +static int ad4170_gpio_set(struct gpio_chip *gc, unsigned int offset, int value) +{ + struct iio_dev *indio_dev = gpiochip_get_data(gc); + struct ad4170_state *st = iio_priv(indio_dev); + int ret; + + if (!iio_device_claim_direct(indio_dev)) + return -EBUSY; + + ret = regmap_assign_bits(st->regmap, AD4170_GPIO_OUTPUT_REG, + BIT(offset), !!value); + + iio_device_release_direct(indio_dev); + return ret; +} + +static int ad4170_gpio_get_direction(struct gpio_chip *gc, unsigned int offset) +{ + struct iio_dev *indio_dev = gpiochip_get_data(gc); + struct ad4170_state *st = iio_priv(indio_dev); + unsigned int val; + int ret; + + if (!iio_device_claim_direct(indio_dev)) + return -EBUSY; + + ret = regmap_read(st->regmap, AD4170_GPIO_MODE_REG, &val); + if (ret) + goto err_release; + + if (val & BIT(offset * 2 + 1)) + ret = GPIO_LINE_DIRECTION_OUT; + else + ret = GPIO_LINE_DIRECTION_IN; + +err_release: + iio_device_release_direct(indio_dev); + + return ret; +} + +static int ad4170_gpio_direction_input(struct gpio_chip *gc, unsigned int offset) +{ + struct iio_dev *indio_dev = gpiochip_get_data(gc); + struct ad4170_state *st = iio_priv(indio_dev); + unsigned long gpio_mask; + int ret; + + if (!iio_device_claim_direct(indio_dev)) + return -EBUSY; + + switch (offset) { + case 0: + gpio_mask = AD4170_GPIO_MODE_GPIO0_MSK; + break; + case 1: + gpio_mask = AD4170_GPIO_MODE_GPIO1_MSK; + break; + case 2: + gpio_mask = AD4170_GPIO_MODE_GPIO2_MSK; + break; + case 3: + gpio_mask = AD4170_GPIO_MODE_GPIO3_MSK; + break; + default: + ret = -EINVAL; + goto err_release; + } + ret = regmap_update_bits(st->regmap, AD4170_GPIO_MODE_REG, gpio_mask, + AD4170_GPIO_MODE_GPIO_INPUT << (2 * offset)); + +err_release: + iio_device_release_direct(indio_dev); + + return ret; +} + +static int ad4170_gpio_direction_output(struct gpio_chip *gc, + unsigned int offset, int value) +{ + struct iio_dev *indio_dev = gpiochip_get_data(gc); + struct ad4170_state *st = iio_priv(indio_dev); + unsigned long gpio_mask; + int ret; + + ret = ad4170_gpio_set(gc, offset, value); + if (ret) + return ret; + + if (!iio_device_claim_direct(indio_dev)) + return -EBUSY; + + switch (offset) { + case 0: + gpio_mask = AD4170_GPIO_MODE_GPIO0_MSK; + break; + case 1: + gpio_mask = AD4170_GPIO_MODE_GPIO1_MSK; + break; + case 2: + gpio_mask = AD4170_GPIO_MODE_GPIO2_MSK; + break; + case 3: + gpio_mask = AD4170_GPIO_MODE_GPIO3_MSK; + break; + default: + ret = -EINVAL; + goto err_release; + } + ret = regmap_update_bits(st->regmap, AD4170_GPIO_MODE_REG, gpio_mask, + AD4170_GPIO_MODE_GPIO_OUTPUT << (2 * offset)); + +err_release: + iio_device_release_direct(indio_dev); + + return ret; +} + +static int ad4170_gpio_init_valid_mask(struct gpio_chip *gc, + unsigned long *valid_mask, + unsigned int ngpios) +{ + struct ad4170_state *st = gpiochip_get_data(gc); + unsigned int i; + + /* Only expose GPIOs that were not assigned any other function. */ + for (i = 0; i < ngpios; i++) { + bool valid = st->gpio_fn[i] == AD4170_GPIO_UNASSIGNED; + + __assign_bit(i, valid_mask, valid); + } + + return 0; +} + +static int ad4170_gpio_init(struct iio_dev *indio_dev) +{ + struct ad4170_state *st = iio_priv(indio_dev); + + st->gpiochip.label = "ad4170_gpios"; + st->gpiochip.base = -1; + st->gpiochip.ngpio = AD4170_NUM_GPIO_PINS; + st->gpiochip.parent = &st->spi->dev; + st->gpiochip.can_sleep = true; + st->gpiochip.init_valid_mask = ad4170_gpio_init_valid_mask; + st->gpiochip.get_direction = ad4170_gpio_get_direction; + st->gpiochip.direction_input = ad4170_gpio_direction_input; + st->gpiochip.direction_output = ad4170_gpio_direction_output; + st->gpiochip.get = ad4170_gpio_get; + st->gpiochip.set_rv = ad4170_gpio_set; + st->gpiochip.owner = THIS_MODULE; + + return devm_gpiochip_add_data(&st->spi->dev, &st->gpiochip, indio_dev); +} + +static int ad4170_validate_excitation_pin(struct ad4170_state *st, u32 pin) +{ + struct device *dev = &st->spi->dev; + unsigned int i; + + /* Check the pin number is valid */ + for (i = 0; i < ARRAY_SIZE(ad4170_iout_pin_tbl); i++) + if (ad4170_iout_pin_tbl[i] == pin) + break; + + if (i == ARRAY_SIZE(ad4170_iout_pin_tbl)) + return dev_err_probe(dev, -EINVAL, + "Invalid excitation pin: %u\n", + pin); + + /* Check the pin is available */ + if (pin <= AD4170_MAX_ANALOG_PINS) { + if (st->pins_fn[pin] != AD4170_PIN_UNASSIGNED) + return dev_err_probe(dev, -EINVAL, + "Pin %u already used with fn %u\n", + pin, st->pins_fn[pin]); + + st->pins_fn[pin] |= AD4170_PIN_CURRENT_OUT; + } else { + unsigned int gpio = pin - AD4170_CURRENT_SRC_I_OUT_PIN_GPIO(0); + + if (st->gpio_fn[gpio] != AD4170_GPIO_UNASSIGNED) + return dev_err_probe(dev, -EINVAL, + "GPIO %u already used with fn %u\n", + gpio, st->gpio_fn[gpio]); + + st->gpio_fn[gpio] |= AD4170_GPIO_AC_EXCITATION; + } + + return 0; +} + +static int ad4170_validate_excitation_pins(struct ad4170_state *st, + u32 *exc_pins, int num_exc_pins) +{ + unsigned int i; + int ret; + + for (i = 0; i < num_exc_pins; i++) { + ret = ad4170_validate_excitation_pin(st, exc_pins[i]); + if (ret) + return ret; + } + return 0; +} + +static const char *const ad4170_i_out_pin_dt_props[] = { + "adi,excitation-pin-0", + "adi,excitation-pin-1", + "adi,excitation-pin-2", + "adi,excitation-pin-3", +}; + +static const char *const ad4170_i_out_val_dt_props[] = { + "adi,excitation-current-0-microamp", + "adi,excitation-current-1-microamp", + "adi,excitation-current-2-microamp", + "adi,excitation-current-3-microamp", +}; + +/* + * Parses firmware data describing output current source setup. There are 4 + * excitation currents (IOUT0 to IOUT3) that can be configured independently. + * Excitation currents are added if they are output on the same pin. + */ +static int ad4170_parse_exc_current(struct ad4170_state *st, + struct fwnode_handle *child, + unsigned int *exc_pins, + unsigned int *exc_curs, + unsigned int *num_exc_pins) +{ + struct device *dev = &st->spi->dev; + unsigned int num_pins, i, j; + u32 pin, val; + int ret; + + num_pins = 0; + for (i = 0; i < AD4170_NUM_CURRENT_SRC; i++) { + /* Parse excitation current output pin properties. */ + pin = AD4170_CURRENT_SRC_I_OUT_PIN_AIN(0); + ret = fwnode_property_read_u32(child, ad4170_i_out_pin_dt_props[i], + &pin); + if (ret) + continue; + + exc_pins[num_pins] = pin; + + /* Parse excitation current value properties. */ + val = ad4170_iout_current_ua_tbl[0]; + fwnode_property_read_u32(child, + ad4170_i_out_val_dt_props[i], &val); + + for (j = 0; j < ARRAY_SIZE(ad4170_iout_current_ua_tbl); j++) + if (ad4170_iout_current_ua_tbl[j] == val) + break; + + if (j == ARRAY_SIZE(ad4170_iout_current_ua_tbl)) + return dev_err_probe(dev, -EINVAL, "Invalid %s: %uuA\n", + ad4170_i_out_val_dt_props[i], val); + + exc_curs[num_pins] = j; + num_pins++; + } + *num_exc_pins = num_pins; + + return 0; +} + +static int ad4170_setup_current_src(struct ad4170_state *st, + struct fwnode_handle *child, + struct ad4170_setup *setup, u32 *exc_pins, + unsigned int *exc_curs, int num_exc_pins, + bool ac_excited) +{ + unsigned int exc_cur_pair, i, j; + int ret; + + for (i = 0; i < num_exc_pins; i++) { + unsigned int exc_cur = exc_curs[i]; + unsigned int pin = exc_pins[i]; + unsigned int current_src = 0; + + for (j = 0; j < AD4170_NUM_CURRENT_SRC; j++) + if (st->cur_src_pins[j] == AD4170_CURRENT_SRC_DISABLED) + break; + + if (j == AD4170_NUM_CURRENT_SRC) + return dev_err_probe(&st->spi->dev, -EINVAL, + "Too many excitation current sources\n"); + + current_src |= FIELD_PREP(AD4170_CURRENT_SRC_I_OUT_PIN_MSK, pin); + current_src |= FIELD_PREP(AD4170_CURRENT_SRC_I_OUT_VAL_MSK, exc_cur); + st->cur_src_pins[j] = pin; + ret = regmap_write(st->regmap, AD4170_CURRENT_SRC_REG(j), + current_src); + if (ret) + return ret; + } + + if (!ac_excited) + return 0; + + if (num_exc_pins < 2) + return dev_err_probe(&st->spi->dev, -EINVAL, + "Current chopping requested but only one pin provided: %u\n", + exc_pins[0]); + + /* + * Two use cases to handle here: + * - 2 pairs of excitation currents; + * - 1 pair of excitation currents. + */ + if (num_exc_pins == 4) { + for (i = 0; i < AD4170_NUM_CURRENT_SRC; i++) + if (st->cur_src_pins[i] != exc_pins[i]) + return dev_err_probe(&st->spi->dev, -EINVAL, + "Unable to use 4 exc pins\n"); + } else { + /* + * Excitation current chopping is configured in pairs. Current + * sources IOUT0 and IOUT1 form pair 1, IOUT2 and IOUT3 make up + * pair 2. So, if current chopping was requested, check if the + * first end of the first pair of excitation currents is + * available. Try the next pair if IOUT0 has already been + * configured for another channel. + */ + i = st->cur_src_pins[0] == exc_pins[0] ? 0 : 2; + + if (st->cur_src_pins[i] != exc_pins[0] || + st->cur_src_pins[i + 1] != exc_pins[1]) + return dev_err_probe(&st->spi->dev, -EINVAL, + "Failed to setup current chopping\n"); + + st->cur_src_pins[i] = exc_pins[0]; + st->cur_src_pins[i + 1] = exc_pins[1]; + + if (i == 0) + exc_cur_pair = AD4170_MISC_CHOP_IEXC_PAIR1; + else + exc_cur_pair = AD4170_MISC_CHOP_IEXC_PAIR2; + } + + /* + * Configure excitation current chopping. + * Chop both pairs if using four excitation pins. + */ + setup->misc |= FIELD_PREP(AD4170_MISC_CHOP_IEXC_MSK, + num_exc_pins == 2 ? + exc_cur_pair : + AD4170_MISC_CHOP_IEXC_BOTH); + + return 0; +} + +static int ad4170_setup_bridge(struct ad4170_state *st, + struct fwnode_handle *child, + struct ad4170_setup *setup, u32 *exc_pins, + unsigned int *exc_curs, int num_exc_pins, + bool ac_excited) +{ + unsigned long gpio_mask; + unsigned int i; + int ret; + + /* + * If a specific current is provided through + * adi,excitation-current-n-microamp, set excitation pins provided + * through adi,excitation-pin-n to excite the bridge circuit. + */ + for (i = 0; i < num_exc_pins; i++) + if (exc_curs[i] > 0) + return ad4170_setup_current_src(st, child, setup, exc_pins, + exc_curs, num_exc_pins, + ac_excited); + + /* + * Else, use predefined ACX1, ACX1 negated, ACX2, ACX2 negated signals + * to AC excite the bridge. Those signals are output on GPIO2, GPIO0, + * GPIO3, and GPIO1, respectively. If only two pins are specified for AC + * excitation, use ACX1 and ACX2 (GPIO2 and GPIO3). + * + * Also, to avoid any short-circuit condition when more than one channel + * is enabled, set GPIO2 and GPIO0 high, and set GPIO1 and GPIO3 low to + * DC excite the bridge whenever a channel without AC excitation is + * selected. That is needed because GPIO pins are controlled by the next + * highest priority GPIO function when a channel doesn't enable AC + * excitation. See datasheet Figure 113 Weigh Scale (AC Excitation) for + * the reference circuit diagram. + */ + if (num_exc_pins == 2) { + setup->misc |= FIELD_PREP(AD4170_MISC_CHOP_ADC_MSK, 0x3); + + gpio_mask = AD4170_GPIO_MODE_GPIO3_MSK | AD4170_GPIO_MODE_GPIO2_MSK; + ret = regmap_update_bits(st->regmap, AD4170_GPIO_MODE_REG, gpio_mask, + FIELD_PREP(AD4170_GPIO_MODE_GPIO3_MSK, + AD4170_GPIO_MODE_GPIO_OUTPUT) | + FIELD_PREP(AD4170_GPIO_MODE_GPIO2_MSK, + AD4170_GPIO_MODE_GPIO_OUTPUT)); + if (ret) + return ret; + + /* + * Set GPIO2 high and GPIO3 low to DC excite the bridge when + * a different channel is selected. + */ + gpio_mask = AD4170_GPIO_OUTPUT_GPIO_MSK(3) | + AD4170_GPIO_OUTPUT_GPIO_MSK(2); + ret = regmap_update_bits(st->regmap, AD4170_GPIO_OUTPUT_REG, gpio_mask, + FIELD_PREP(AD4170_GPIO_OUTPUT_GPIO_MSK(3), 0) | + FIELD_PREP(AD4170_GPIO_OUTPUT_GPIO_MSK(2), 1)); + if (ret) + return ret; + + st->gpio_fn[3] |= AD4170_GPIO_OUTPUT; + st->gpio_fn[2] |= AD4170_GPIO_OUTPUT; + } else { + setup->misc |= FIELD_PREP(AD4170_MISC_CHOP_ADC_MSK, 0x2); + + gpio_mask = AD4170_GPIO_MODE_GPIO3_MSK | AD4170_GPIO_MODE_GPIO2_MSK | + AD4170_GPIO_MODE_GPIO1_MSK | AD4170_GPIO_MODE_GPIO0_MSK; + ret = regmap_update_bits(st->regmap, AD4170_GPIO_MODE_REG, gpio_mask, + FIELD_PREP(AD4170_GPIO_MODE_GPIO3_MSK, + AD4170_GPIO_MODE_GPIO_OUTPUT) | + FIELD_PREP(AD4170_GPIO_MODE_GPIO2_MSK, + AD4170_GPIO_MODE_GPIO_OUTPUT) | + FIELD_PREP(AD4170_GPIO_MODE_GPIO1_MSK, + AD4170_GPIO_MODE_GPIO_OUTPUT) | + FIELD_PREP(AD4170_GPIO_MODE_GPIO0_MSK, + AD4170_GPIO_MODE_GPIO_OUTPUT)); + if (ret) + return ret; + + /* + * Set GPIO2 and GPIO0 high, and set GPIO1 and GPIO3 low to DC + * excite the bridge when a different channel is selected. + */ + gpio_mask = AD4170_GPIO_OUTPUT_GPIO_MSK(3) | + AD4170_GPIO_OUTPUT_GPIO_MSK(2) | + AD4170_GPIO_OUTPUT_GPIO_MSK(1) | + AD4170_GPIO_OUTPUT_GPIO_MSK(0); + ret = regmap_update_bits(st->regmap, AD4170_GPIO_OUTPUT_REG, gpio_mask, + FIELD_PREP(AD4170_GPIO_OUTPUT_GPIO_MSK(3), 0) | + FIELD_PREP(AD4170_GPIO_OUTPUT_GPIO_MSK(2), 1) | + FIELD_PREP(AD4170_GPIO_OUTPUT_GPIO_MSK(1), 0) | + FIELD_PREP(AD4170_GPIO_OUTPUT_GPIO_MSK(0), 1)); + if (ret) + return ret; + + st->gpio_fn[3] |= AD4170_GPIO_OUTPUT; + st->gpio_fn[2] |= AD4170_GPIO_OUTPUT; + st->gpio_fn[1] |= AD4170_GPIO_OUTPUT; + st->gpio_fn[0] |= AD4170_GPIO_OUTPUT; + } + + return 0; +} + +static int ad4170_setup_rtd(struct ad4170_state *st, + struct fwnode_handle *child, + struct ad4170_setup *setup, u32 *exc_pins, + unsigned int *exc_curs, int num_exc_pins, bool ac_excited) +{ + return ad4170_setup_current_src(st, child, setup, exc_pins, + exc_curs, num_exc_pins, ac_excited); +} + +static int ad4170_parse_external_sensor(struct ad4170_state *st, + struct fwnode_handle *child, + struct ad4170_setup *setup, + struct iio_chan_spec *chan, + unsigned int s_type) +{ + unsigned int num_exc_pins, reg_val; + struct device *dev = &st->spi->dev; + u32 pins[2], exc_pins[4], exc_curs[4]; + bool ac_excited; + int ret; + + ret = fwnode_property_read_u32_array(child, "diff-channels", pins, + ARRAY_SIZE(pins)); + if (ret) + return dev_err_probe(dev, ret, + "Failed to read sensor diff-channels\n"); + + chan->differential = true; + chan->channel = pins[0]; + chan->channel2 = pins[1]; + + ret = ad4170_parse_exc_current(st, child, exc_pins, exc_curs, &num_exc_pins); + if (ret) + return ret; + + /* The external sensor may not need excitation from the ADC chip. */ + if (num_exc_pins == 0) + return 0; + + ret = ad4170_validate_excitation_pins(st, exc_pins, num_exc_pins); + if (ret) + return ret; + + ac_excited = fwnode_property_read_bool(child, "adi,excitation-ac"); + + if (s_type == AD4170_THERMOCOUPLE_SENSOR) { + if (st->pins_fn[chan->channel2] & AD4170_PIN_VBIAS) { + reg_val = BIT(chan->channel2); + ret = regmap_write(st->regmap, AD4170_V_BIAS_REG, reg_val); + if (ret) + dev_err_probe(dev, ret, "Failed to set vbias\n"); + } + } + if (s_type == AD4170_WEIGH_SCALE_SENSOR) + ret = ad4170_setup_bridge(st, child, setup, exc_pins, exc_curs, + num_exc_pins, ac_excited); + else + ret = ad4170_setup_rtd(st, child, setup, exc_pins, exc_curs, + num_exc_pins, ac_excited); + + return ret; +} + +static int ad4170_parse_reference(struct ad4170_state *st, + struct fwnode_handle *child, + struct ad4170_setup *setup) +{ + struct device *dev = &st->spi->dev; + const char *propname; + u32 aux; + int ret; + + /* Optional positive reference buffering */ + propname = "adi,positive-reference-buffer"; + ret = device_property_match_property_string(dev, propname, + ad4170_ref_buf_str, + ARRAY_SIZE(ad4170_ref_buf_str)); + + /* Default to full precharge buffer enabled. */ + setup->afe |= FIELD_PREP(AD4170_AFE_REF_BUF_P_MSK, + ret >= 0 ? ret : AD4170_REF_BUF_FULL); + + /* Optional negative reference buffering */ + propname = "adi,negative-reference-buffer"; + ret = device_property_match_property_string(dev, propname, + ad4170_ref_buf_str, + ARRAY_SIZE(ad4170_ref_buf_str)); + + /* Default to full precharge buffer enabled. */ + setup->afe |= FIELD_PREP(AD4170_AFE_REF_BUF_M_MSK, + ret >= 0 ? ret : AD4170_REF_BUF_FULL); + + /* Optional voltage reference selection */ + propname = "adi,reference-select"; + aux = AD4170_REF_REFOUT; /* Default reference selection. */ + fwnode_property_read_u32(child, propname, &aux); + if (aux > AD4170_REF_AVDD) + return dev_err_probe(dev, -EINVAL, "Invalid %s: %u\n", + propname, aux); + + setup->afe |= FIELD_PREP(AD4170_AFE_REF_SELECT_MSK, aux); + + return 0; +} + +static int ad4170_parse_adc_channel_type(struct device *dev, + struct fwnode_handle *child, + struct iio_chan_spec *chan) +{ + const char *propname, *propname2; + int ret, ret2; + u32 pins[2]; + + propname = "single-channel"; + propname2 = "diff-channels"; + if (!fwnode_property_present(child, propname) && + !fwnode_property_present(child, propname2)) + return dev_err_probe(dev, -EINVAL, + "Channel must define one of %s or %s.\n", + propname, propname2); + + /* Parse differential channel configuration */ + ret = fwnode_property_read_u32_array(child, propname2, pins, + ARRAY_SIZE(pins)); + if (!ret) { + chan->differential = true; + chan->channel = pins[0]; + chan->channel2 = pins[1]; + return 0; + } + /* Failed to parse diff chan so try pseudo-diff chan props */ + + propname2 = "common-mode-channel"; + if (fwnode_property_present(child, propname) && + !fwnode_property_present(child, propname2)) + return dev_err_probe(dev, -EINVAL, + "When %s is defined, %s must be defined too\n", + propname, propname2); + + /* Parse pseudo-differential channel configuration */ + ret = fwnode_property_read_u32(child, propname, &pins[0]); + ret2 = fwnode_property_read_u32(child, propname2, &pins[1]); + + if (!ret && !ret2) { + chan->differential = false; + chan->channel = pins[0]; + chan->channel2 = pins[1]; + return 0; + } + return dev_err_probe(dev, -EINVAL, + "Failed to parse channel %lu input. %d, %d\n", + chan->address, ret, ret2); +} + +static int ad4170_parse_channel_node(struct iio_dev *indio_dev, + struct fwnode_handle *child, + unsigned int chan_num) +{ + struct ad4170_state *st = iio_priv(indio_dev); + unsigned int s_type = AD4170_ADC_SENSOR; + struct device *dev = &st->spi->dev; + struct ad4170_chan_info *chan_info; + struct ad4170_setup *setup; + struct iio_chan_spec *chan; + unsigned int ref_select; + unsigned int ch_reg; + bool bipolar; + int ret; + + ret = fwnode_property_read_u32(child, "reg", &ch_reg); + if (ret) + return dev_err_probe(dev, ret, "Failed to read channel reg\n"); + + if (ch_reg >= AD4170_MAX_ADC_CHANNELS) + return dev_err_probe(dev, -EINVAL, + "Channel idx greater than no of channels\n"); + + chan = &st->chans[chan_num]; + *chan = ad4170_channel_template; + + chan->address = ch_reg; + chan->scan_index = ch_reg; + chan_info = &st->chan_infos[chan->address]; + + chan_info->setup_num = AD4170_INVALID_SETUP; + chan_info->initialized = true; + + setup = &chan_info->setup; + ret = ad4170_parse_reference(st, child, setup); + if (ret) + return ret; + + ret = fwnode_property_match_property_string(child, "adi,sensor-type", + ad4170_sensor_type, + ARRAY_SIZE(ad4170_sensor_type)); + + /* Default to conventional ADC channel if sensor type not present */ + s_type = ret < 0 ? AD4170_ADC_SENSOR : ret; + switch (s_type) { + case AD4170_ADC_SENSOR: + ret = ad4170_parse_adc_channel_type(dev, child, chan); + if (ret) + return ret; + + break; + case AD4170_WEIGH_SCALE_SENSOR: + case AD4170_THERMOCOUPLE_SENSOR: + case AD4170_RTD_SENSOR: + ret = ad4170_parse_external_sensor(st, child, setup, chan, s_type); + if (ret) + return ret; + + break; + default: + return -EINVAL; + } + + bipolar = fwnode_property_read_bool(child, "bipolar"); + setup->afe |= FIELD_PREP(AD4170_AFE_BIPOLAR_MSK, bipolar); + if (bipolar) + chan->scan_type.sign = 's'; + else + chan->scan_type.sign = 'u'; + + ret = ad4170_validate_channel(st, chan); + if (ret) + return ret; + + ref_select = FIELD_GET(AD4170_AFE_REF_SELECT_MSK, setup->afe); + ret = ad4170_get_input_range(st, chan, ch_reg, ref_select); + if (ret < 0) + return dev_err_probe(dev, ret, "Invalid input config\n"); + + chan_info->input_range_uv = ret; + return 0; +} + +static int ad4170_parse_channels(struct iio_dev *indio_dev) +{ + struct ad4170_state *st = iio_priv(indio_dev); + struct device *dev = &st->spi->dev; + unsigned int num_channels; + unsigned int chan_num; + int ret; + + num_channels = device_get_child_node_count(dev); + + if (num_channels > AD4170_MAX_ADC_CHANNELS) + return dev_err_probe(dev, -EINVAL, "Too many channels\n"); + + /* Add one for temperature */ + num_channels = min(num_channels + 1, AD4170_MAX_ADC_CHANNELS); + + chan_num = 0; + device_for_each_child_node_scoped(dev, child) { + ret = ad4170_parse_channel_node(indio_dev, child, chan_num++); + if (ret) + return ret; + } + + /* + * Add internal temperature sensor channel if the maximum number of + * channels has not been reached. + */ + if (num_channels < AD4170_MAX_ADC_CHANNELS) { + struct ad4170_setup *setup = &st->chan_infos[chan_num].setup; + + st->chans[chan_num] = ad4170_temp_channel_template; + st->chans[chan_num].address = chan_num; + st->chans[chan_num].scan_index = chan_num; + + st->chan_infos[chan_num].setup_num = AD4170_INVALID_SETUP; + st->chan_infos[chan_num].initialized = true; + + setup->afe |= FIELD_PREP(AD4170_AFE_REF_SELECT_MSK, + AD4170_REF_AVDD); + + ret = ad4170_get_input_range(st, &st->chans[chan_num], chan_num, + AD4170_REF_AVDD); + if (ret < 0) + return dev_err_probe(dev, ret, "Invalid input config\n"); + + st->chan_infos[chan_num].input_range_uv = ret; + chan_num++; + } + + /* Add timestamp channel */ + struct iio_chan_spec ts_chan = IIO_CHAN_SOFT_TIMESTAMP(chan_num); + + st->chans[chan_num] = ts_chan; + num_channels = num_channels + 1; + + indio_dev->num_channels = num_channels; + indio_dev->channels = st->chans; + + return 0; +} + +static struct ad4170_state *clk_hw_to_ad4170(struct clk_hw *hw) +{ + return container_of(hw, struct ad4170_state, int_clk_hw); +} + +static unsigned long ad4170_sel_clk(struct ad4170_state *st, + unsigned int clk_sel) +{ + st->clock_ctrl &= ~AD4170_CLOCK_CTRL_CLOCKSEL_MSK; + st->clock_ctrl |= FIELD_PREP(AD4170_CLOCK_CTRL_CLOCKSEL_MSK, clk_sel); + return regmap_write(st->regmap, AD4170_CLOCK_CTRL_REG, st->clock_ctrl); +} + +static unsigned long ad4170_clk_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + return AD4170_INT_CLOCK_16MHZ; +} + +static int ad4170_clk_output_is_enabled(struct clk_hw *hw) +{ + struct ad4170_state *st = clk_hw_to_ad4170(hw); + u32 clk_sel; + + clk_sel = FIELD_GET(AD4170_CLOCK_CTRL_CLOCKSEL_MSK, st->clock_ctrl); + return clk_sel == AD4170_CLOCK_CTRL_CLOCKSEL_INT_OUT; +} + +static int ad4170_clk_output_prepare(struct clk_hw *hw) +{ + struct ad4170_state *st = clk_hw_to_ad4170(hw); + + return ad4170_sel_clk(st, AD4170_CLOCK_CTRL_CLOCKSEL_INT_OUT); +} + +static void ad4170_clk_output_unprepare(struct clk_hw *hw) +{ + struct ad4170_state *st = clk_hw_to_ad4170(hw); + + ad4170_sel_clk(st, AD4170_CLOCK_CTRL_CLOCKSEL_INT); +} + +static const struct clk_ops ad4170_int_clk_ops = { + .recalc_rate = ad4170_clk_recalc_rate, + .is_enabled = ad4170_clk_output_is_enabled, + .prepare = ad4170_clk_output_prepare, + .unprepare = ad4170_clk_output_unprepare, +}; + +static int ad4170_register_clk_provider(struct iio_dev *indio_dev) +{ + struct ad4170_state *st = iio_priv(indio_dev); + struct device *dev = indio_dev->dev.parent; + struct clk_init_data init = {}; + int ret; + + if (device_property_read_string(dev, "clock-output-names", &init.name)) { + init.name = devm_kasprintf(dev, GFP_KERNEL, "%pfw", + dev_fwnode(dev)); + if (!init.name) + return -ENOMEM; + } + + init.ops = &ad4170_int_clk_ops; + + st->int_clk_hw.init = &init; + ret = devm_clk_hw_register(dev, &st->int_clk_hw); + if (ret) + return ret; + + return devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get, + &st->int_clk_hw); +} + +static int ad4170_clock_select(struct iio_dev *indio_dev) +{ + struct ad4170_state *st = iio_priv(indio_dev); + struct device *dev = &st->spi->dev; + struct clk *ext_clk; + int ret; + + ext_clk = devm_clk_get_optional_enabled(dev, NULL); + if (IS_ERR(ext_clk)) + return dev_err_probe(dev, PTR_ERR(ext_clk), + "Failed to get external clock\n"); + + if (!ext_clk) { + /* Use internal clock reference */ + st->mclk_hz = AD4170_INT_CLOCK_16MHZ; + st->clock_ctrl |= FIELD_PREP(AD4170_CLOCK_CTRL_CLOCKSEL_MSK, + AD4170_CLOCK_CTRL_CLOCKSEL_INT_OUT); + + if (!device_property_present(&st->spi->dev, "#clock-cells")) + return 0; + + return ad4170_register_clk_provider(indio_dev); + } + + /* Read optional clock-names prop to specify the external clock type */ + ret = device_property_match_property_string(dev, "clock-names", + ad4170_clk_sel, + ARRAY_SIZE(ad4170_clk_sel)); + + ret = ret < 0 ? 0 : ret; /* Default to external clock if no clock-names */ + st->clock_ctrl |= FIELD_PREP(AD4170_CLOCK_CTRL_CLOCKSEL_MSK, + AD4170_CLOCK_CTRL_CLOCKSEL_EXT + ret); + + st->mclk_hz = clk_get_rate(ext_clk); + if (st->mclk_hz < AD4170_EXT_CLOCK_MHZ_MIN || + st->mclk_hz > AD4170_EXT_CLOCK_MHZ_MAX) { + return dev_err_probe(dev, -EINVAL, + "Invalid external clock frequency %u\n", + st->mclk_hz); + } + + return 0; +} + +static int ad4170_parse_firmware(struct iio_dev *indio_dev) +{ + unsigned int vbias_pins[AD4170_MAX_ANALOG_PINS]; + struct ad4170_state *st = iio_priv(indio_dev); + struct device *dev = &st->spi->dev; + unsigned int num_vbias_pins; + int reg_data, ret; + u32 int_pin_sel; + unsigned int i; + + ret = ad4170_clock_select(indio_dev); + if (ret) + return dev_err_probe(dev, ret, "Failed to setup device clock\n"); + + ret = regmap_write(st->regmap, AD4170_CLOCK_CTRL_REG, st->clock_ctrl); + if (ret) + return ret; + + for (i = 0; i < AD4170_NUM_CURRENT_SRC; i++) + st->cur_src_pins[i] = AD4170_CURRENT_SRC_DISABLED; + + /* On power on, device defaults to using SDO pin for data ready signal */ + int_pin_sel = AD4170_INT_PIN_SDO; + ret = device_property_match_property_string(dev, "interrupt-names", + ad4170_int_pin_names, + ARRAY_SIZE(ad4170_int_pin_names)); + if (ret >= 0) + int_pin_sel = ret; + + reg_data = FIELD_PREP(AD4170_PIN_MUXING_DIG_AUX1_CTRL_MSK, + int_pin_sel == AD4170_INT_PIN_DIG_AUX1 ? + AD4170_PIN_MUXING_DIG_AUX1_RDY : + AD4170_PIN_MUXING_DIG_AUX1_DISABLED); + + ret = regmap_update_bits(st->regmap, AD4170_PIN_MUXING_REG, + AD4170_PIN_MUXING_DIG_AUX1_CTRL_MSK, reg_data); + if (ret) + return ret; + + ret = device_property_count_u32(dev, "adi,vbias-pins"); + if (ret > 0) { + if (ret > AD4170_MAX_ANALOG_PINS) + return dev_err_probe(dev, -EINVAL, + "Too many vbias pins %u\n", ret); + + num_vbias_pins = ret; + + ret = device_property_read_u32_array(dev, "adi,vbias-pins", + vbias_pins, + num_vbias_pins); + if (ret) + return dev_err_probe(dev, ret, + "Failed to read vbias pins\n"); + + for (i = 0; i < num_vbias_pins; i++) + st->pins_fn[vbias_pins[i]] |= AD4170_PIN_VBIAS; + } + + ret = ad4170_parse_channels(indio_dev); + if (ret) + return ret; + + /* Only create a GPIO chip if flagged for it */ + if (device_property_read_bool(dev, "gpio-controller")) { + ret = ad4170_gpio_init(indio_dev); + if (ret) + return ret; + } + + return 0; +} + +static int ad4170_initial_config(struct iio_dev *indio_dev) +{ + struct ad4170_state *st = iio_priv(indio_dev); + struct device *dev = &st->spi->dev; + unsigned int i; + int ret; + + ad4170_fill_sps_tbl(st); + + ret = regmap_update_bits(st->regmap, AD4170_ADC_CTRL_REG, + AD4170_ADC_CTRL_MODE_MSK, + FIELD_PREP(AD4170_ADC_CTRL_MODE_MSK, + AD4170_ADC_CTRL_MODE_IDLE)); + if (ret) + return dev_err_probe(dev, ret, + "Failed to set ADC mode to idle\n"); + + for (i = 0; i < indio_dev->num_channels; i++) { + struct ad4170_chan_info *chan_info; + struct iio_chan_spec const *chan; + struct ad4170_setup *setup; + unsigned int val; + + chan = &indio_dev->channels[i]; + if (chan->type == IIO_TIMESTAMP) + continue; + + chan_info = &st->chan_infos[chan->address]; + + setup = &chan_info->setup; + setup->gain = AD4170_GAIN_REG_DEFAULT; + ret = ad4170_write_channel_setup(st, chan->address, false); + if (ret) + return dev_err_probe(dev, ret, + "Failed to write channel setup\n"); + + val = FIELD_PREP(AD4170_CHAN_MAP_AINP_MSK, chan->channel) | + FIELD_PREP(AD4170_CHAN_MAP_AINM_MSK, chan->channel2); + + ret = regmap_write(st->regmap, AD4170_CHAN_MAP_REG(i), val); + if (ret) + return dev_err_probe(dev, ret, + "Failed to write CHAN_MAP_REG\n"); + + ret = ad4170_set_channel_freq(st, chan, + AD4170_DEFAULT_SAMP_RATE, 0); + if (ret) + return dev_err_probe(dev, ret, + "Failed to set channel freq\n"); + + ret = ad4170_fill_scale_tbl(indio_dev, chan); + if (ret) + return dev_err_probe(dev, ret, + "Failed to fill scale tbl\n"); + } + + /* Disable all channels to avoid reading from unexpected channel */ + ret = regmap_write(st->regmap, AD4170_CHAN_EN_REG, 0); + if (ret) + return dev_err_probe(dev, ret, + "Failed to disable channels\n"); + + /* + * Configure channels to share the same data output register, i.e. data + * can be read from the same register address regardless of channel + * number. + */ + return regmap_update_bits(st->regmap, AD4170_ADC_CTRL_REG, + AD4170_ADC_CTRL_MULTI_DATA_REG_SEL_MSK, + AD4170_ADC_CTRL_MULTI_DATA_REG_SEL_MSK); +} + +static int ad4170_prepare_spi_message(struct ad4170_state *st) +{ + /* + * Continuous data register read is enabled on buffer postenable so + * no instruction phase is needed meaning we don't need to send the + * register address to read data. Transfer only needs the read buffer. + */ + st->xfer.rx_buf = &st->rx_buf; + st->xfer.len = BITS_TO_BYTES(ad4170_channel_template.scan_type.realbits); + + spi_message_init_with_transfers(&st->msg, &st->xfer, 1); + + return devm_spi_optimize_message(&st->spi->dev, st->spi, &st->msg); +} + +static int ad4170_buffer_postenable(struct iio_dev *indio_dev) +{ + struct ad4170_state *st = iio_priv(indio_dev); + int ret; + + ret = regmap_update_bits(st->regmap, AD4170_ADC_CTRL_REG, + AD4170_ADC_CTRL_MODE_MSK, + FIELD_PREP(AD4170_ADC_CTRL_MODE_MSK, + AD4170_ADC_CTRL_MODE_CONT)); + if (ret) + return ret; + + /* + * This enables continuous read of the ADC data register. The ADC must + * be in continuous conversion mode. + */ + return regmap_update_bits(st->regmap, AD4170_ADC_CTRL_REG, + AD4170_ADC_CTRL_CONT_READ_MSK, + FIELD_PREP(AD4170_ADC_CTRL_CONT_READ_MSK, + AD4170_ADC_CTRL_CONT_READ_ENABLE)); +} + +static int ad4170_buffer_predisable(struct iio_dev *indio_dev) +{ + struct ad4170_state *st = iio_priv(indio_dev); + unsigned int i; + int ret; + + /* + * Use a high register address (virtual register) to request a write of + * 0xA5 to the ADC during the first 8 SCLKs of the ADC data read cycle, + * thus exiting continuous read. + */ + ret = regmap_write(st->regmap, AD4170_ADC_CTRL_CONT_READ_EXIT_REG, 0); + if (ret) + return ret; + + ret = regmap_update_bits(st->regmap, AD4170_ADC_CTRL_REG, + AD4170_ADC_CTRL_CONT_READ_MSK, + FIELD_PREP(AD4170_ADC_CTRL_CONT_READ_MSK, + AD4170_ADC_CTRL_CONT_READ_DISABLE)); + if (ret) + return ret; + + ret = regmap_update_bits(st->regmap, AD4170_ADC_CTRL_REG, + AD4170_ADC_CTRL_MODE_MSK, + FIELD_PREP(AD4170_ADC_CTRL_MODE_MSK, + AD4170_ADC_CTRL_MODE_IDLE)); + if (ret) + return ret; + + /* + * The ADC sequences through all the enabled channels (see datasheet + * page 95). That can lead to incorrect channel being read if a + * single-shot read (or buffered read with different active_scan_mask) + * is done after buffer disable. Disable all channels so only requested + * channels will be read. + */ + for (i = 0; i < indio_dev->num_channels; i++) { + if (indio_dev->channels[i].type == IIO_TIMESTAMP) + continue; + + ret = ad4170_set_channel_enable(st, i, false); + if (ret) + return ret; + } + + return 0; +} + +static bool ad4170_validate_scan_mask(struct iio_dev *indio_dev, + const unsigned long *scan_mask) +{ + unsigned int masklength = iio_get_masklength(indio_dev); + unsigned int enabled; + + /* + * The channel sequencer cycles through the enabled channels in + * sequential order, from channel 0 to channel 15, bypassing disabled + * channels. When more than one channel is enabled, channel 0 must + * always be enabled. See datasheet channel_en register description at + * page 95. + */ + enabled = bitmap_weight(scan_mask, masklength); + if (enabled > 1) + return test_bit(0, scan_mask); + + return enabled == 1; +} + +static const struct iio_buffer_setup_ops ad4170_buffer_ops = { + .postenable = ad4170_buffer_postenable, + .predisable = ad4170_buffer_predisable, + .validate_scan_mask = ad4170_validate_scan_mask, +}; + +static irqreturn_t ad4170_trigger_handler(int irq, void *p) +{ + struct iio_poll_func *pf = p; + struct iio_dev *indio_dev = pf->indio_dev; + struct ad4170_state *st = iio_priv(indio_dev); + unsigned int chan_index; + unsigned int i = 0; + int ret; + + iio_for_each_active_channel(indio_dev, chan_index) { + ret = spi_sync(st->spi, &st->msg); + if (ret) + goto err_out; + + memcpy(&st->bounce_buffer[i++], st->rx_buf, ARRAY_SIZE(st->rx_buf)); + } + + iio_push_to_buffers_with_ts(indio_dev, st->bounce_buffer, + sizeof(st->bounce_buffer), + iio_get_time_ns(indio_dev)); +err_out: + iio_trigger_notify_done(indio_dev->trig); + return IRQ_HANDLED; +} + +static const struct iio_trigger_ops ad4170_trigger_ops = { + .validate_device = iio_trigger_validate_own_device, +}; + +static irqreturn_t ad4170_irq_handler(int irq, void *dev_id) +{ + struct iio_dev *indio_dev = dev_id; + struct ad4170_state *st = iio_priv(indio_dev); + + if (iio_buffer_enabled(indio_dev)) + iio_trigger_poll(st->trig); + else + complete(&st->completion); + + return IRQ_HANDLED; +}; + +static int ad4170_trigger_setup(struct iio_dev *indio_dev) +{ + struct ad4170_state *st = iio_priv(indio_dev); + struct device *dev = &st->spi->dev; + int ret; + + st->trig = devm_iio_trigger_alloc(dev, "%s-trig%d", + indio_dev->name, + iio_device_id(indio_dev)); + if (!st->trig) + return -ENOMEM; + + st->trig->ops = &ad4170_trigger_ops; + + iio_trigger_set_drvdata(st->trig, indio_dev); + ret = devm_iio_trigger_register(dev, st->trig); + if (ret) + return dev_err_probe(dev, ret, "Failed to register trigger\n"); + + indio_dev->trig = iio_trigger_get(st->trig); + + return 0; +} + +static int ad4170_regulator_setup(struct ad4170_state *st) +{ + struct device *dev = &st->spi->dev; + int ret; + + /* Required regulators */ + ret = devm_regulator_get_enable_read_voltage(dev, "avdd"); + if (ret < 0) + return dev_err_probe(dev, ret, "Failed to get AVDD voltage.\n"); + + st->vrefs_uv[AD4170_AVDD_SUP] = ret; + + ret = devm_regulator_get_enable_read_voltage(dev, "iovdd"); + if (ret < 0) + return dev_err_probe(dev, ret, "Failed to get IOVDD voltage.\n"); + + st->vrefs_uv[AD4170_IOVDD_SUP] = ret; + + /* Optional regulators */ + ret = devm_regulator_get_enable_read_voltage(dev, "avss"); + if (ret < 0 && ret != -ENODEV) + return dev_err_probe(dev, ret, "Failed to get AVSS voltage.\n"); + + /* + * Assume AVSS at GND (0V) if not provided. + * REVISIT: AVSS is never above system ground level (i.e. AVSS is either + * GND or a negative voltage). But we currently don't have support for + * reading negative voltages with the regulator framework. So, the + * current AD4170 support reads a positive value from the regulator, + * then inverts sign to make that negative. + */ + st->vrefs_uv[AD4170_AVSS_SUP] = ret == -ENODEV ? 0 : -ret; + + ret = devm_regulator_get_enable_read_voltage(dev, "refin1p"); + if (ret < 0 && ret != -ENODEV) + return dev_err_probe(dev, ret, "Failed to get REFIN+ voltage.\n"); + + st->vrefs_uv[AD4170_REFIN1P_SUP] = ret; + + ret = devm_regulator_get_enable_read_voltage(dev, "refin1n"); + if (ret < 0 && ret != -ENODEV) + return dev_err_probe(dev, ret, "Failed to get REFIN- voltage.\n"); + + /* + * Negative supplies are assumed to provide negative voltage. + * REVISIT when support for negative regulator voltage read be available + * in the regulator framework. + */ + st->vrefs_uv[AD4170_REFIN1N_SUP] = ret == -ENODEV ? -ENODEV : -ret; + + ret = devm_regulator_get_enable_read_voltage(dev, "refin2p"); + if (ret < 0 && ret != -ENODEV) + return dev_err_probe(dev, ret, "Failed to get REFIN2+ voltage.\n"); + + st->vrefs_uv[AD4170_REFIN2P_SUP] = ret; + + ret = devm_regulator_get_enable_read_voltage(dev, "refin2n"); + if (ret < 0 && ret != -ENODEV) + return dev_err_probe(dev, ret, "Failed to get REFIN2- voltage.\n"); + + /* + * Negative supplies are assumed to provide negative voltage. + * REVISIT when support for negative regulator voltage read be available + * in the regulator framework. + */ + st->vrefs_uv[AD4170_REFIN2N_SUP] = ret == -ENODEV ? -ENODEV : -ret; + + return 0; +} + +static int ad4170_probe(struct spi_device *spi) +{ + const struct ad4170_chip_info *chip; + struct device *dev = &spi->dev; + struct iio_dev *indio_dev; + struct ad4170_state *st; + int ret; + + indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); + if (!indio_dev) + return -ENOMEM; + + st = iio_priv(indio_dev); + st->spi = spi; + + ret = devm_mutex_init(dev, &st->lock); + if (ret) + return ret; + + chip = spi_get_device_match_data(spi); + if (!chip) + return -EINVAL; + + indio_dev->name = chip->name; + indio_dev->info = &ad4170_info; + + st->regmap = devm_regmap_init(dev, NULL, st, &ad4170_regmap_config); + if (IS_ERR(st->regmap)) + return dev_err_probe(dev, PTR_ERR(st->regmap), + "Failed to initialize regmap\n"); + + ret = ad4170_regulator_setup(st); + if (ret) + return ret; + + ret = ad4170_soft_reset(st); + if (ret) + return ret; + + ret = ad4170_parse_firmware(indio_dev); + if (ret) + return dev_err_probe(dev, ret, "Failed to parse firmware\n"); + + ret = ad4170_initial_config(indio_dev); + if (ret) + return dev_err_probe(dev, ret, "Failed to setup device\n"); + + init_completion(&st->completion); + + if (spi->irq) { + ret = devm_request_irq(dev, spi->irq, &ad4170_irq_handler, + IRQF_ONESHOT, indio_dev->name, indio_dev); + if (ret) + return ret; + + ret = ad4170_trigger_setup(indio_dev); + if (ret) + return ret; + } + + ret = ad4170_prepare_spi_message(st); + if (ret) + return dev_err_probe(dev, ret, "Failed to prepare SPI message\n"); + + ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL, + &ad4170_trigger_handler, + &ad4170_buffer_ops); + if (ret) + return dev_err_probe(dev, ret, "Failed to setup read buffer\n"); + + return devm_iio_device_register(dev, indio_dev); +} + +static const struct spi_device_id ad4170_id_table[] = { + { "ad4170-4", (kernel_ulong_t)&ad4170_chip_info }, + { "ad4190-4", (kernel_ulong_t)&ad4190_chip_info }, + { "ad4195-4", (kernel_ulong_t)&ad4195_chip_info }, + { } +}; +MODULE_DEVICE_TABLE(spi, ad4170_id_table); + +static const struct of_device_id ad4170_of_match[] = { + { .compatible = "adi,ad4170-4", .data = &ad4170_chip_info }, + { .compatible = "adi,ad4190-4", .data = &ad4190_chip_info }, + { .compatible = "adi,ad4195-4", .data = &ad4195_chip_info }, + { } +}; +MODULE_DEVICE_TABLE(of, ad4170_of_match); + +static struct spi_driver ad4170_driver = { + .driver = { + .name = "ad4170-4", + .of_match_table = ad4170_of_match, + }, + .probe = ad4170_probe, + .id_table = ad4170_id_table, +}; +module_spi_driver(ad4170_driver); + +MODULE_AUTHOR("Ana-Maria Cusco <ana-maria.cusco@analog.com>"); +MODULE_AUTHOR("Marcelo Schmitt <marcelo.schmitt@analog.com>"); +MODULE_DESCRIPTION("Analog Devices AD4170 SPI driver"); +MODULE_LICENSE("GPL"); |