On Tue, 10 Jan 2023 11:01:23 -0500 Hugo Villeneuve <hugo@xxxxxxxxxxx> wrote: > From: Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx> > > The Texas Instruments ADS7924 is a 4 channels, 12-bit analog to > digital converter (ADC) with an I2C interface. > > Datasheet: https://www.ti.com/lit/gpn/ads7924 > > Signed-off-by: Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx> > --- > MAINTAINERS | 7 + > drivers/iio/adc/Kconfig | 11 + > drivers/iio/adc/Makefile | 1 + > drivers/iio/adc/ti-ads7924.c | 492 +++++++++++++++++++++++++++++++++++ > 4 files changed, 511 insertions(+) > create mode 100644 drivers/iio/adc/ti-ads7924.c > > diff --git a/MAINTAINERS b/MAINTAINERS > index 9ff472ca1244..94eb68076f0c 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -20776,6 +20776,13 @@ M: Robert Richter <rric@xxxxxxxxxx> > S: Odd Fixes > F: drivers/gpio/gpio-thunderx.c > > +TI ADS7924 ADC DRIVER > +M: Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx> > +L: linux-iio@xxxxxxxxxxxxxxx > +S: Supported > +F: Documentation/devicetree/bindings/iio/adc/ti,ads7924.yaml > +F: drivers/iio/adc/ti-ads7924.c > + > TI AM437X VPFE DRIVER > M: "Lad, Prabhakar" <prabhakar.csengg@xxxxxxxxx> > L: linux-media@xxxxxxxxxxxxxxx > diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig > index 7d6e74189a2d..99468c64daf9 100644 > --- a/drivers/iio/adc/Kconfig > +++ b/drivers/iio/adc/Kconfig > @@ -1208,6 +1208,17 @@ config TI_ADS1015 > This driver can also be built as a module. If so, the module will be > called ti-ads1015. > > +config TI_ADS7924 > + tristate "Texas Instruments ADS7924 ADC" > + depends on I2C > + select REGMAP_I2C > + help > + If you say yes here you get support for Texas Instruments ADS7924 > + 4 channels, 12-bit I2C ADC chip. > + > + This driver can also be built as a module. If so, the module will be > + called ti-ads7924. > + > config TI_ADS7950 > tristate "Texas Instruments ADS7950 ADC driver" > depends on SPI && GPIOLIB > diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile > index 6e08415c3f3a..1e5bdf47a091 100644 > --- a/drivers/iio/adc/Makefile > +++ b/drivers/iio/adc/Makefile > @@ -107,6 +107,7 @@ obj-$(CONFIG_TI_ADC108S102) += ti-adc108s102.o > obj-$(CONFIG_TI_ADC128S052) += ti-adc128s052.o > obj-$(CONFIG_TI_ADC161S626) += ti-adc161s626.o > obj-$(CONFIG_TI_ADS1015) += ti-ads1015.o > +obj-$(CONFIG_TI_ADS7924) += ti-ads7924.o > obj-$(CONFIG_TI_ADS7950) += ti-ads7950.o > obj-$(CONFIG_TI_ADS8344) += ti-ads8344.o > obj-$(CONFIG_TI_ADS8688) += ti-ads8688.o > diff --git a/drivers/iio/adc/ti-ads7924.c b/drivers/iio/adc/ti-ads7924.c > new file mode 100644 > index 000000000000..8384f3451236 > --- /dev/null > +++ b/drivers/iio/adc/ti-ads7924.c > @@ -0,0 +1,492 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * IIO driver for Texas Instruments ADS7924 ADC, 12-bit, 4-Channels, I2C > + * > + * iio/adc/ti-ads7924.c > + * Author: Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx> > + * 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/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 4 > +#define ADS7924_BITS 12 > +#define ADS7924_DATA_SHIFT 4 > + > +/* Registers. */ > +#define ADS7924_MODECNTRL_REG 0x00 > +#define ADS7924_INTCNTRL_REG 0x01 > +#define ADS7924_DATA0_U_REG 0x02 > +#define ADS7924_DATA0_L_REG 0x03 > +#define ADS7924_DATA1_U_REG 0x04 > +#define ADS7924_DATA1_L_REG 0x05 > +#define ADS7924_DATA2_U_REG 0x06 > +#define ADS7924_DATA2_L_REG 0x07 > +#define ADS7924_DATA3_U_REG 0x08 > +#define ADS7924_DATA3_L_REG 0x09 > +#define ADS7924_ULR0_REG 0x0A > +#define ADS7924_LLR0_REG 0x0B > +#define ADS7924_ULR1_REG 0x0C > +#define ADS7924_LLR1_REG 0x0D > +#define ADS7924_ULR2_REG 0x0E > +#define ADS7924_LLR2_REG 0x0F > +#define ADS7924_ULR3_REG 0x10 > +#define ADS7924_LLR3_REG 0x11 > +#define ADS7924_INTCONFIG_REG 0x12 > +#define ADS7924_SLPCONFIG_REG 0x13 > +#define ADS7924_ACQCONFIG_REG 0x14 > +#define ADS7924_PWRCONFIG_REG 0x15 > +#define ADS7924_RESET_REG 0x16 > + > +/* > + * 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 BIT(7) > + > +#define ADS7924_MODECNTRL_MODE_MASK GENMASK(7, 2) > + > +#define ADS7924_MODECNTRL_SEL_MASK GENMASK(1, 0) > + > +#define ADS7924_CFG_INTPOL_BIT 1 > +#define ADS7924_CFG_INTTRIG_BIT 0 > + > +#define ADS7924_CFG_INTPOL_MASK BIT(ADS7924_CFG_INTPOL_BIT) > +#define ADS7924_CFG_INTTRIG_MASK BIT(ADS7924_CFG_INTTRIG_BIT) > + > +/* Interrupt pin polarity */ > +#define ADS7924_CFG_INTPOL_LOW 0 > +#define ADS7924_CFG_INTPOL_HIGH 1 > + > +/* Interrupt pin signaling */ > +#define ADS7924_CFG_INTTRIG_LEVEL 0 > +#define ADS7924_CFG_INTTRIG_EDGE 1 > + > +/* Mode control values */ > +#define ADS7924_MODECNTRL_IDLE 0x00 > +#define ADS7924_MODECNTRL_AWAKE 0x20 > +#define ADS7924_MODECNTRL_MANUAL_SINGLE 0x30 > +#define ADS7924_MODECNTRL_MANUAL_SCAN 0x32 > +#define ADS7924_MODECNTRL_AUTO_SINGLE 0x31 > +#define ADS7924_MODECNTRL_AUTO_SCAN 0x33 > +#define ADS7924_MODECNTRL_AUTO_SINGLE_SLEEP 0x39 > +#define ADS7924_MODECNTRL_AUTO_SCAN_SLEEP 0x3B > +#define ADS7924_MODECNTRL_AUTO_BURST_SLEEP 0x3F > + > +#define ADS7924_ACQTIME_MASK GENMASK(4, 0) > + > +#define ADS7924_PWRUPTIME_MASK GENMASK(4, 0) > + > +/* > + * 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 0 /* Bypass (0us). */ > + > +/* > + * 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 6 > + > +/* The conversion time is always 4μs and cannot be programmed by the user. */ > +#define ADS7924_CONVTIME_US 4 > + > +#define ADS7924_TOTAL_CONVTIME_US (ADS7924_PWRUPTIME_US + ADS7924_ACQTIME_US + \ > + ADS7924_CONVTIME_US) > + > +#define ADS7924_SLEEP_DELAY_MS 2000 > + > +#define ADS7924_V_CHAN(_chan, _addr) { \ > + .type = IIO_VOLTAGE, \ > + .indexed = 1, \ > + .channel = _chan, \ > + .address = _addr, \ > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ > + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ > + .datasheet_name = "AIN"#_chan, \ > +} > + > +struct ads7924_data { > + struct device *dev; > + struct regmap *regmap; > + struct regulator *vref_reg; > + > + /* GPIO descriptor for device hard-reset pin. */ > + struct gpio_desc *reset_gpio; > + > + /* > + * Protects ADC ops, e.g: concurrent sysfs/buffered > + * data reads, configuration updates > + */ > + struct mutex lock; > + > + /* > + * Set to true when the ADC is switched to the continuous-conversion > + * mode and exits from a power-down state. This flag is used to avoid > + * getting the stale result from the conversion register. > + */ > + bool conv_invalid; > +}; > + > +static bool ads7924_is_writeable_reg(struct device *dev, unsigned int reg) > +{ > + switch (reg) { > + case ADS7924_MODECNTRL_REG: > + case ADS7924_INTCNTRL_REG: > + case ADS7924_ULR0_REG: > + case ADS7924_LLR0_REG: > + case ADS7924_ULR1_REG: > + case ADS7924_LLR1_REG: > + case ADS7924_ULR2_REG: > + case ADS7924_LLR2_REG: > + case ADS7924_ULR3_REG: > + case ADS7924_LLR3_REG: > + case ADS7924_INTCONFIG_REG: > + case ADS7924_SLPCONFIG_REG: > + case ADS7924_ACQCONFIG_REG: > + case ADS7924_PWRCONFIG_REG: > + case ADS7924_RESET_REG: > + return true; > + default: > + return false; > + } > +} > + > +static const struct regmap_config ads7924_regmap_config = { > + .reg_bits = 8, > + .val_bits = 8, > + .max_register = ADS7924_RESET_REG, > + .writeable_reg = ads7924_is_writeable_reg, > +}; > + > +static const struct iio_chan_spec ads7924_channels[] = { > + ADS7924_V_CHAN(0, ADS7924_DATA0_U_REG), > + ADS7924_V_CHAN(1, ADS7924_DATA1_U_REG), > + ADS7924_V_CHAN(2, ADS7924_DATA2_U_REG), > + ADS7924_V_CHAN(3, ADS7924_DATA3_U_REG), > +}; > + > +static > +int ads7924_get_adc_result(struct ads7924_data *data, > + struct iio_chan_spec const *chan, int *val) > +{ > + int ret; > + __be16 be_val; > + > + if (chan->channel < 0 || chan->channel >= ADS7924_CHANNELS) > + return -EINVAL; > + > + if (data->conv_invalid) { > + int conv_time; > + > + conv_time = ADS7924_TOTAL_CONVTIME_US; > + /* Allow 10% for internal clock inaccuracy. */ > + conv_time += conv_time / 10; > + usleep_range(conv_time, conv_time + 1); > + data->conv_invalid = false; > + } > + > + ret = regmap_raw_read(data->regmap, ADS7924_AUTO_INCREMENT_BIT | > + chan->address, &be_val, sizeof(be_val)); > + if (ret) > + return ret; > + > + *val = be16_to_cpu(be_val); > + *val = *val >> ADS7924_DATA_SHIFT; > + > + return ret; > +} > + > +static int ads7924_read_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, int *val, > + int *val2, long mask) > +{ > + int ret, vref_uv; > + struct ads7924_data *data = iio_priv(indio_dev); > + > + switch (mask) { > + case IIO_CHAN_INFO_RAW: { > + mutex_lock(&data->lock); > + ret = ads7924_get_adc_result(data, chan, val); > + mutex_unlock(&data->lock); > + if (ret < 0) > + dev_dbg(data->dev, "%s error1\n", __func__); > + else > + ret = IIO_VAL_INT; > + break; > + } > + case IIO_CHAN_INFO_SCALE: > + vref_uv = regulator_get_voltage(data->vref_reg); > + if (vref_uv < 0) { > + /* dummy regulator "get_voltage" returns -EINVAL */ > + ret = -EINVAL; > + } else { > + *val = vref_uv / 1000; /* Convert reg voltage to mV */ > + *val2 = ADS7924_BITS; > + ret = IIO_VAL_FRACTIONAL_LOG2; > + } > + break; > + default: > + ret = -EINVAL; > + break; > + } > + > + return ret; > +} > + > +static const struct iio_info ads7924_info = { > + .read_raw = ads7924_read_raw, > +}; > + > +static int ads7924_get_channels_config(struct i2c_client *client, > + struct iio_dev *indio_dev) > +{ > + struct ads7924_data *priv = iio_priv(indio_dev); > + struct device *dev = priv->dev; > + struct fwnode_handle *node; > + int num_channels = 0; > + > + device_for_each_child_node(dev, node) { > + u32 pval; > + unsigned int channel; > + > + if (fwnode_property_read_u32(node, "reg", &pval)) { > + dev_err(dev, "invalid reg on %pfw\n", node); > + continue; > + } > + > + channel = pval; > + if (channel >= ADS7924_CHANNELS) { > + dev_err(dev, "invalid channel index %d on %pfw\n", > + channel, node); > + continue; > + } > + > + num_channels++; > + } > + > + if (num_channels > 0) { > + dev_dbg(dev, "found %d ADC channels\n", num_channels); > + return 0; > + } else { > + return -EINVAL; > + } > +} > + > +static int ads7924_set_conv_mode(struct ads7924_data *data, int mode) > +{ > + int ret; > + unsigned int mode_field; > + struct device *dev = data->dev; > + > + /* > + * When switching between modes, be sure to first select the Awake mode > + * and then switch to the desired mode. This procedure ensures the > + * internal control logic is properly synchronized. > + */ > + if (mode != ADS7924_MODECNTRL_IDLE) { > + mode_field = FIELD_PREP(ADS7924_MODECNTRL_MODE_MASK, > + ADS7924_MODECNTRL_AWAKE); > + > + ret = regmap_update_bits(data->regmap, ADS7924_MODECNTRL_REG, > + ADS7924_MODECNTRL_MODE_MASK, > + mode_field); > + if (ret) { > + dev_warn(dev, "failed to set awake mode (%pe)\n", > + ERR_PTR(ret)); > + return ret; > + } > + } > + > + mode_field = FIELD_PREP(ADS7924_MODECNTRL_MODE_MASK, mode); > + > + ret = regmap_update_bits(data->regmap, ADS7924_MODECNTRL_REG, > + ADS7924_MODECNTRL_MODE_MASK, mode_field); > + if (ret) > + dev_warn(dev, "failed to set mode %d (%pe)\n", mode, > + ERR_PTR(ret)); > + > + return ret; > +} > + > +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. */ > + } else { > + int ret; > + > + /* > + * A write of 10101010 to this register will generate a > + * software reset of the ADS7924. > + */ > + ret = regmap_write(data->regmap, ADS7924_RESET_REG, 0b10101010); > + if (ret) > + return ret; > + } > + > + return 0; > +}; > + > +static void ads7924_reg_disable(void *data) > +{ > + regulator_disable(data); > +} > + > +static void ads7924_set_idle_mode(void *data) > +{ > + ads7924_set_conv_mode(data, ADS7924_MODECNTRL_IDLE); > +} > + > +static int ads7924_probe(struct i2c_client *client) > +{ > + struct iio_dev *indio_dev; > + struct ads7924_data *data; > + struct device *dev = &client->dev; > + int ret; > + > + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); > + if (!indio_dev) > + return -ENOMEM; Would it be a good idea to also use dev_err_probe() here? Hugo. > + > + data = iio_priv(indio_dev); > + > + data->dev = dev; > + > + /* Initialize the reset GPIO as output with an initial value of 0. */ > + data->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW); > + if (IS_ERR(data->reset_gpio)) > + return dev_err_probe(dev, PTR_ERR(data->reset_gpio), > + "failed to get request reset GPIO\n"); > + > + mutex_init(&data->lock); > + > + indio_dev->name = "ads7924"; > + indio_dev->modes = INDIO_DIRECT_MODE; > + > + indio_dev->channels = ads7924_channels; > + indio_dev->num_channels = ARRAY_SIZE(ads7924_channels); > + indio_dev->info = &ads7924_info; > + > + ret = ads7924_get_channels_config(client, indio_dev); > + if (ret < 0) > + return dev_err_probe(dev, ret, > + "failed to get channels configuration\n"); > + > + data->regmap = devm_regmap_init_i2c(client, &ads7924_regmap_config); > + if (IS_ERR(data->regmap)) > + return dev_err_probe(dev, PTR_ERR(data->regmap), > + "failed to init regmap\n"); > + > + data->vref_reg = devm_regulator_get(dev, "vref"); > + if (IS_ERR(data->vref_reg)) > + return dev_err_probe(dev, PTR_ERR(data->vref_reg), > + "failed to get vref regulator\n"); > + > + ret = regulator_enable(data->vref_reg); > + if (ret) > + return dev_err_probe(dev, ret, > + "failed to enable regulator\n"); > + > + ret = devm_add_action_or_reset(dev, ads7924_reg_disable, data->vref_reg); > + if (ret) > + return dev_err_probe(dev, ret, > + "failed to add regulator disable action\n"); > + > + ret = ads7924_reset(indio_dev); > + if (ret < 0) > + return dev_err_probe(dev, ret, > + "failed to reset device\n"); > + > + ret = devm_add_action_or_reset(dev, ads7924_set_idle_mode, data); > + if (ret) > + return dev_err_probe(dev, ret, > + "failed to add idle mode action\n"); > + > + ret = ads7924_set_conv_mode(data, ADS7924_MODECNTRL_AUTO_SCAN); > + if (ret) > + return dev_err_probe(dev, ret, > + "failed to set conversion mode\n"); > + > + /* Use minimum signal acquire time. */ > + ret = regmap_update_bits(data->regmap, ADS7924_ACQCONFIG_REG, > + ADS7924_ACQTIME_MASK, > + FIELD_PREP(ADS7924_ACQTIME_MASK, 0)); > + if (ret < 0) > + return dev_err_probe(dev, ret, > + "failed to configure signal acquire time\n"); > + > + /* Disable power-up time. */ > + ret = regmap_update_bits(data->regmap, ADS7924_PWRCONFIG_REG, > + ADS7924_PWRUPTIME_MASK, > + FIELD_PREP(ADS7924_PWRUPTIME_MASK, 0)); > + if (ret < 0) > + return dev_err_probe(dev, ret, > + "failed to configure power-up time\n"); > + > + data->conv_invalid = true; > + > + ret = devm_iio_device_register(dev, indio_dev); > + if (ret < 0) > + return dev_err_probe(dev, ret, > + "failed to register IIO device\n"); > + > + return 0; > +} > + > +static const struct i2c_device_id ads7924_id[] = { > + { "ads7924", 0 }, > + {} > +}; > +MODULE_DEVICE_TABLE(i2c, ads7924_id); > + > +static const struct of_device_id ads7924_of_match[] = { > + { .compatible = "ti,ads7924", }, > + {} > +}; > +MODULE_DEVICE_TABLE(of, ads7924_of_match); > + > +static struct i2c_driver ads7924_driver = { > + .driver = { > + .name = "ads7924", > + .of_match_table = ads7924_of_match, > + }, > + .probe_new = ads7924_probe, > + .id_table = ads7924_id, > +}; > + > +module_i2c_driver(ads7924_driver); > + > +MODULE_AUTHOR("Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx>"); > +MODULE_DESCRIPTION("Texas Instruments ADS7924 ADC I2C driver"); > +MODULE_LICENSE("GPL"); > -- > 2.30.2 > > -- Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx>
