// SPDX-License-Identifier: GPL-2.0 /* * IIO driver for Texas Instruments ADS7924 ADC, 12-bit, 4-Channels, I2C * * Author: Hugo Villeneuve <[email protected]> * Copyright 2022 DimOnOff * * based on iio/adc/ti-ads1015.c * Copyright (c) 2016, Intel Corporation. * * Datasheet: https://www.ti.com/lit/gpn/ads7924 */ #include <linux/bitfield.h> #include <linux/delay.h> #include <linux/gpio/consumer.h> #include <linux/init.h> #include <linux/irq.h> #include <linux/i2c.h> #include <linux/module.h> #include <linux/mutex.h> #include <linux/regmap.h> #include <linux/regulator/consumer.h> #include <linux/iio/iio.h> #include <linux/iio/types.h> #define ADS7924_CHANNELS … #define ADS7924_BITS … #define ADS7924_DATA_SHIFT … /* Registers. */ #define ADS7924_MODECNTRL_REG … #define ADS7924_INTCNTRL_REG … #define ADS7924_DATA0_U_REG … #define ADS7924_DATA0_L_REG … #define ADS7924_DATA1_U_REG … #define ADS7924_DATA1_L_REG … #define ADS7924_DATA2_U_REG … #define ADS7924_DATA2_L_REG … #define ADS7924_DATA3_U_REG … #define ADS7924_DATA3_L_REG … #define ADS7924_ULR0_REG … #define ADS7924_LLR0_REG … #define ADS7924_ULR1_REG … #define ADS7924_LLR1_REG … #define ADS7924_ULR2_REG … #define ADS7924_LLR2_REG … #define ADS7924_ULR3_REG … #define ADS7924_LLR3_REG … #define ADS7924_INTCONFIG_REG … #define ADS7924_SLPCONFIG_REG … #define ADS7924_ACQCONFIG_REG … #define ADS7924_PWRCONFIG_REG … #define ADS7924_RESET_REG … /* * Register address INC bit: when set to '1', the register address is * automatically incremented after every register read which allows convenient * reading of multiple registers. Set INC to '0' when reading a single register. */ #define ADS7924_AUTO_INCREMENT_BIT … #define ADS7924_MODECNTRL_MODE_MASK … #define ADS7924_MODECNTRL_SEL_MASK … #define ADS7924_CFG_INTPOL_BIT … #define ADS7924_CFG_INTTRIG_BIT … #define ADS7924_CFG_INTPOL_MASK … #define ADS7924_CFG_INTTRIG_MASK … /* Interrupt pin polarity */ #define ADS7924_CFG_INTPOL_LOW … #define ADS7924_CFG_INTPOL_HIGH … /* Interrupt pin signaling */ #define ADS7924_CFG_INTTRIG_LEVEL … #define ADS7924_CFG_INTTRIG_EDGE … /* Mode control values */ #define ADS7924_MODECNTRL_IDLE … #define ADS7924_MODECNTRL_AWAKE … #define ADS7924_MODECNTRL_MANUAL_SINGLE … #define ADS7924_MODECNTRL_MANUAL_SCAN … #define ADS7924_MODECNTRL_AUTO_SINGLE … #define ADS7924_MODECNTRL_AUTO_SCAN … #define ADS7924_MODECNTRL_AUTO_SINGLE_SLEEP … #define ADS7924_MODECNTRL_AUTO_SCAN_SLEEP … #define ADS7924_MODECNTRL_AUTO_BURST_SLEEP … #define ADS7924_ACQTIME_MASK … #define ADS7924_PWRUPTIME_MASK … /* * The power-up time is allowed to elapse whenever the device has been shutdown * in idle mode. Power-up time can allow external circuits, such as an * operational amplifier, between the MUXOUT and ADCIN pins to turn on. * The nominal time programmed by the PUTIME[4:0] register bits is given by: * t PU = PWRUPTIME[4:0] × 2 μs * If a power-up time is not required, set the bits to '0' to effectively bypass. */ #define ADS7924_PWRUPTIME_US … /* * Acquisition Time according to ACQTIME[4:0] register bits. * The Acquisition Time is given by: * t ACQ = (ACQTIME[4:0] × 2 μs) + 6 μs * Using default value of 0 for ACQTIME[4:0] results in a minimum acquisition * time of 6us. */ #define ADS7924_ACQTIME_US … /* The conversion time is always 4μs and cannot be programmed by the user. */ #define ADS7924_CONVTIME_US … #define ADS7924_TOTAL_CONVTIME_US … #define ADS7924_V_CHAN(_chan, _addr) … struct ads7924_data { … }; static bool ads7924_is_writeable_reg(struct device *dev, unsigned int reg) { … } static const struct regmap_config ads7924_regmap_config = …; static const struct iio_chan_spec ads7924_channels[] = …; static int ads7924_get_adc_result(struct ads7924_data *data, struct iio_chan_spec const *chan, int *val) { … } static int ads7924_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long mask) { … } static const struct iio_info ads7924_info = …; static int ads7924_get_channels_config(struct i2c_client *client, struct iio_dev *indio_dev) { … } static int ads7924_set_conv_mode(struct ads7924_data *data, int mode) { … } static int ads7924_reset(struct iio_dev *indio_dev) { struct ads7924_data *data = iio_priv(indio_dev); if (data->reset_gpio) { gpiod_set_value(data->reset_gpio, 1); /* Assert. */ /* Educated guess: assert time not specified in datasheet... */ mdelay(100); gpiod_set_value(data->reset_gpio, 0); /* Deassert. */ return 0; } /* * A write of 10101010 to this register will generate a * software reset of the ADS7924. */ return regmap_write(data->regmap, ADS7924_RESET_REG, 0b10101010); }; static void ads7924_reg_disable(void *data) { … } static void ads7924_set_idle_mode(void *data) { … } static int ads7924_probe(struct i2c_client *client) { … } static const struct i2c_device_id ads7924_id[] = …; MODULE_DEVICE_TABLE(i2c, ads7924_id); static const struct of_device_id ads7924_of_match[] = …; MODULE_DEVICE_TABLE(of, ads7924_of_match); static struct i2c_driver ads7924_driver = …; module_i2c_driver(…) …; MODULE_AUTHOR(…) …; MODULE_DESCRIPTION(…) …; MODULE_LICENSE(…) …;
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