On Thu, 28 Feb 2019 11:26:08 -0300
Renato Lui Geh <renato...@gmail.com> wrote:
> Move ad7780 ADC driver out of staging and into the mainline.
>
> The ad7780 is a sigma-delta analog to digital converter. This driver provides
> reading voltage values and status bits from both the ad778x and ad717x series.
> Its interface also allows writing on the FILTER and GAIN GPIO pins on the
> ad778x.
>
> Signed-off-by: Renato Lui Geh <renato...@gmail.com>
> Signed-off-by: Giuliano Belinassi <giuliano.belina...@usp.br>
> Co-developed-by: Giuliano Belinassi <giuliano.belina...@usp.br>
I think this is fine up to the minor tweaks Alex raised in the
precursor patches. Should be good to move in v5 :)
Jonathan
> ---
> Changes in v3:
> - Changes unrelated to moving the driver to main tree were resent as
> individual patches
> Changes in v4:
> - Removed line warning it was safe to build the ad7780 driver by
> default
>
> About the above change in v4, I was unsure whether it was ok to add this
> in this patch, as 'move out of staging' patches should be just that. But
> this change is so minimal I'm willing to risk a v5. Bottom line: should
> I add this change as another patch?
>
> drivers/iio/adc/Kconfig | 12 +
> drivers/iio/adc/Makefile | 1 +
> drivers/iio/adc/ad7780.c | 365 +++++++++++++++++++++++++++++++
> drivers/staging/iio/adc/Kconfig | 13 --
> drivers/staging/iio/adc/Makefile | 1 -
> drivers/staging/iio/adc/ad7780.c | 365 -------------------------------
> 6 files changed, 378 insertions(+), 379 deletions(-)
> create mode 100644 drivers/iio/adc/ad7780.c
> delete mode 100644 drivers/staging/iio/adc/ad7780.c
>
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> index f3cc7a31bce5..6b36a45bd09f 100644
> --- a/drivers/iio/adc/Kconfig
> +++ b/drivers/iio/adc/Kconfig
> @@ -108,6 +108,18 @@ config AD7766
> To compile this driver as a module, choose M here: the module will be
> called ad7766.
>
> +config AD7780
> + tristate "Analog Devices AD7780 and similar ADCs driver"
> + depends on SPI
> + depends on GPIOLIB || COMPILE_TEST
> + select AD_SIGMA_DELTA
> + help
> + Say yes here to build support for Analog Devices AD7170, AD7171,
> + AD7780 and AD7781 SPI analog to digital converters (ADC).
> +
> + To compile this driver as a module, choose M here: the
> + module will be called ad7780.
> +
> config AD7791
> tristate "Analog Devices AD7791 ADC driver"
> depends on SPI
> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
> index ea5031348052..b48852157115 100644
> --- a/drivers/iio/adc/Makefile
> +++ b/drivers/iio/adc/Makefile
> @@ -15,6 +15,7 @@ obj-$(CONFIG_AD7606_IFACE_PARALLEL) += ad7606_par.o
> obj-$(CONFIG_AD7606_IFACE_SPI) += ad7606_spi.o
> obj-$(CONFIG_AD7606) += ad7606.o
> obj-$(CONFIG_AD7766) += ad7766.o
> +obj-$(CONFIG_AD7780) += ad7780.o
> obj-$(CONFIG_AD7791) += ad7791.o
> obj-$(CONFIG_AD7793) += ad7793.o
> obj-$(CONFIG_AD7887) += ad7887.o
> diff --git a/drivers/iio/adc/ad7780.c b/drivers/iio/adc/ad7780.c
> new file mode 100644
> index 000000000000..aa1ddd0c45ee
> --- /dev/null
> +++ b/drivers/iio/adc/ad7780.c
> @@ -0,0 +1,365 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * AD7170/AD7171 and AD7780/AD7781 SPI ADC driver
> + *
> + * Copyright 2011 Analog Devices Inc.
> + * Copyright 2019 Renato Lui Geh
> + */
> +
> +#include <linux/interrupt.h>
> +#include <linux/device.h>
> +#include <linux/kernel.h>
> +#include <linux/slab.h>
> +#include <linux/sysfs.h>
> +#include <linux/spi/spi.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/err.h>
> +#include <linux/sched.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/module.h>
> +#include <linux/bits.h>
> +
> +#include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>
> +#include <linux/iio/adc/ad_sigma_delta.h>
> +
> +#define AD7780_RDY BIT(7)
> +#define AD7780_FILTER BIT(6)
> +#define AD7780_ERR BIT(5)
> +#define AD7780_GAIN BIT(2)
> +
> +#define AD7170_ID 0
> +#define AD7171_ID 1
> +#define AD7780_ID 1
> +#define AD7781_ID 0
> +
> +#define AD7780_ID_MASK (BIT(3) | BIT(4))
> +
> +#define AD7780_PATTERN_GOOD 1
> +#define AD7780_PATTERN_MASK GENMASK(1, 0)
> +
> +#define AD7170_PATTERN_GOOD 5
> +#define AD7170_PATTERN_MASK GENMASK(2, 0)
> +
> +#define AD7780_GAIN_MIDPOINT 64
> +#define AD7780_FILTER_MIDPOINT 13350
> +
> +static const unsigned int ad778x_gain[2] = { 1, 128 };
> +static const unsigned int ad778x_odr_avail[2] = { 10000, 16700 };
> +
> +struct ad7780_chip_info {
> + struct iio_chan_spec channel;
> + unsigned int pattern_mask;
> + unsigned int pattern;
> + bool is_ad778x;
> +};
> +
> +struct ad7780_state {
> + const struct ad7780_chip_info *chip_info;
> + struct regulator *reg;
> + struct gpio_desc *powerdown_gpio;
> + struct gpio_desc *gain_gpio;
> + struct gpio_desc *filter_gpio;
> + unsigned int gain;
> + unsigned int odr;
> + unsigned int int_vref_mv;
> +
> + struct ad_sigma_delta sd;
> +};
> +
> +enum ad7780_supported_device_ids {
> + ID_AD7170,
> + ID_AD7171,
> + ID_AD7780,
> + ID_AD7781,
> +};
> +
> +static struct ad7780_state *ad_sigma_delta_to_ad7780(struct ad_sigma_delta
> *sd)
> +{
> + return container_of(sd, struct ad7780_state, sd);
> +}
> +
> +static int ad7780_set_mode(struct ad_sigma_delta *sigma_delta,
> + enum ad_sigma_delta_mode mode)
> +{
> + struct ad7780_state *st = ad_sigma_delta_to_ad7780(sigma_delta);
> + unsigned int val;
> +
> + switch (mode) {
> + case AD_SD_MODE_SINGLE:
> + case AD_SD_MODE_CONTINUOUS:
> + val = 1;
> + break;
> + default:
> + val = 0;
> + break;
> + }
> +
> + gpiod_set_value(st->powerdown_gpio, val);
> +
> + return 0;
> +}
> +
> +static int ad7780_read_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + int *val,
> + int *val2,
> + long m)
> +{
> + struct ad7780_state *st = iio_priv(indio_dev);
> + int voltage_uv;
> +
> + switch (m) {
> + case IIO_CHAN_INFO_RAW:
> + return ad_sigma_delta_single_conversion(indio_dev, chan, val);
> + case IIO_CHAN_INFO_SCALE:
> + voltage_uv = regulator_get_voltage(st->reg);
> + if (voltage_uv < 0)
> + return voltage_uv;
> + voltage_uv /= 1000;
> + *val = voltage_uv * st->gain;
> + *val2 = chan->scan_type.realbits - 1;
> + st->int_vref_mv = voltage_uv;
> + return IIO_VAL_FRACTIONAL_LOG2;
> + case IIO_CHAN_INFO_OFFSET:
> + *val = -(1 << (chan->scan_type.realbits - 1));
> + return IIO_VAL_INT;
> + case IIO_CHAN_INFO_SAMP_FREQ:
> + *val = st->odr;
> + return IIO_VAL_INT;
> + default:
> + break;
> + }
> +
> + return -EINVAL;
> +}
> +
> +static int ad7780_write_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + int val,
> + int val2,
> + long m)
> +{
> + struct ad7780_state *st = iio_priv(indio_dev);
> + const struct ad7780_chip_info *chip_info = st->chip_info;
> + unsigned long long vref;
> + unsigned int full_scale, gain;
> +
> + if (!chip_info->is_ad778x)
> + return 0;
> +
> + switch (m) {
> + case IIO_CHAN_INFO_SCALE:
> + if (val != 0)
> + return -EINVAL;
> +
> + vref = st->int_vref_mv * 1000000LL;
> + full_scale = 1 << (chip_info->channel.scan_type.realbits - 1);
> + gain = DIV_ROUND_CLOSEST(vref, full_scale);
> + gain = DIV_ROUND_CLOSEST(gain, val2);
> + st->gain = gain;
> + if (gain < AD7780_GAIN_MIDPOINT)
> + gain = 0;
> + else
> + gain = 1;
> + gpiod_set_value(st->gain_gpio, gain);
> + break;
> + case IIO_CHAN_INFO_SAMP_FREQ:
> + if (1000*val + val2/1000 < AD7780_FILTER_MIDPOINT)
> + val = 0;
> + else
> + val = 1;
> + st->odr = ad778x_odr_avail[val];
> + gpiod_set_value(st->filter_gpio, val);
> + break;
> + default:
> + break;
> + }
> +
> + return 0;
> +}
> +
> +static int ad7780_postprocess_sample(struct ad_sigma_delta *sigma_delta,
> + unsigned int raw_sample)
> +{
> + struct ad7780_state *st = ad_sigma_delta_to_ad7780(sigma_delta);
> + const struct ad7780_chip_info *chip_info = st->chip_info;
> +
> + if ((raw_sample & AD7780_ERR) ||
> + ((raw_sample & chip_info->pattern_mask) != chip_info->pattern))
> + return -EIO;
> +
> + if (chip_info->is_ad778x) {
> + st->gain = ad778x_gain[raw_sample & AD7780_GAIN];
> + st->odr = ad778x_odr_avail[raw_sample & AD7780_FILTER];
> + }
> +
> + return 0;
> +}
> +
> +static const struct ad_sigma_delta_info ad7780_sigma_delta_info = {
> + .set_mode = ad7780_set_mode,
> + .postprocess_sample = ad7780_postprocess_sample,
> + .has_registers = false,
> +};
> +
> +#define AD7780_CHANNEL(bits, wordsize) \
> + AD_SD_CHANNEL(1, 0, 0, bits, 32, wordsize - bits)
> +#define AD7170_CHANNEL(bits, wordsize) \
> + AD_SD_CHANNEL_NO_SAMP_FREQ(1, 0, 0, bits, 32, wordsize - bits)
> +
> +static const struct ad7780_chip_info ad7780_chip_info_tbl[] = {
> + [ID_AD7170] = {
> + .channel = AD7170_CHANNEL(12, 24),
> + .pattern = AD7170_PATTERN_GOOD,
> + .pattern_mask = AD7170_PATTERN_MASK,
> + .is_ad778x = false,
> + },
> + [ID_AD7171] = {
> + .channel = AD7170_CHANNEL(16, 24),
> + .pattern = AD7170_PATTERN_GOOD,
> + .pattern_mask = AD7170_PATTERN_MASK,
> + .is_ad778x = false,
> + },
> + [ID_AD7780] = {
> + .channel = AD7780_CHANNEL(24, 32),
> + .pattern = AD7780_PATTERN_GOOD,
> + .pattern_mask = AD7780_PATTERN_MASK,
> + .is_ad778x = true,
> + },
> + [ID_AD7781] = {
> + .channel = AD7780_CHANNEL(20, 32),
> + .pattern = AD7780_PATTERN_GOOD,
> + .pattern_mask = AD7780_PATTERN_MASK,
> + .is_ad778x = true,
> + },
> +};
> +
> +static const struct iio_info ad7780_info = {
> + .read_raw = ad7780_read_raw,
> + .write_raw = ad7780_write_raw,
> +};
> +
> +static int ad7780_probe(struct spi_device *spi)
> +{
> + struct ad7780_state *st;
> + struct iio_dev *indio_dev;
> + int ret;
> +
> + indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
> + if (!indio_dev)
> + return -ENOMEM;
> +
> + st = iio_priv(indio_dev);
> + st->gain = 1;
> +
> + ad_sd_init(&st->sd, indio_dev, spi, &ad7780_sigma_delta_info);
> +
> + st->chip_info =
> + &ad7780_chip_info_tbl[spi_get_device_id(spi)->driver_data];
> +
> + spi_set_drvdata(spi, indio_dev);
> +
> + indio_dev->dev.parent = &spi->dev;
> + indio_dev->name = spi_get_device_id(spi)->name;
> + indio_dev->modes = INDIO_DIRECT_MODE;
> + indio_dev->channels = &st->chip_info->channel;
> + indio_dev->num_channels = 1;
> + indio_dev->info = &ad7780_info;
> +
> + st->powerdown_gpio = devm_gpiod_get_optional(&spi->dev,
> + "powerdown",
> + GPIOD_OUT_LOW);
> + if (IS_ERR(st->powerdown_gpio)) {
> + ret = PTR_ERR(st->powerdown_gpio);
> + dev_err(&spi->dev, "Failed to request powerdown GPIO: %d\n",
> + ret);
> + return ret;
> + }
> +
> + if (st->chip_info->is_ad778x) {
> + st->gain_gpio = devm_gpiod_get_optional(&spi->dev,
> + "adi,gain",
> + GPIOD_OUT_HIGH);
> + if (IS_ERR(st->gain_gpio)) {
> + ret = PTR_ERR(st->gain_gpio);
> + dev_err(&spi->dev, "Failed to request gain GPIO: %d\n",
> + ret);
> + return ret;
> + }
> +
> + st->filter_gpio = devm_gpiod_get_optional(&spi->dev,
> + "adi,filter",
> + GPIOD_OUT_HIGH);
> + if (IS_ERR(st->filter_gpio)) {
> + ret = PTR_ERR(st->filter_gpio);
> + dev_err(&spi->dev,
> + "Failed to request filter GPIO: %d\n",
> + ret);
> + return ret;
> + }
> + }
> +
> + st->reg = devm_regulator_get(&spi->dev, "avdd");
> + if (IS_ERR(st->reg))
> + return PTR_ERR(st->reg);
> +
> + ret = regulator_enable(st->reg);
> + if (ret) {
> + dev_err(&spi->dev, "Failed to enable specified AVdd supply\n");
> + return ret;
> + }
> +
> + ret = ad_sd_setup_buffer_and_trigger(indio_dev);
> + if (ret)
> + goto error_disable_reg;
> +
> + ret = iio_device_register(indio_dev);
> + if (ret)
> + goto error_cleanup_buffer_and_trigger;
> +
> + return 0;
> +
> +error_cleanup_buffer_and_trigger:
> + ad_sd_cleanup_buffer_and_trigger(indio_dev);
> +error_disable_reg:
> + regulator_disable(st->reg);
> +
> + return ret;
> +}
> +
> +static int ad7780_remove(struct spi_device *spi)
> +{
> + struct iio_dev *indio_dev = spi_get_drvdata(spi);
> + struct ad7780_state *st = iio_priv(indio_dev);
> +
> + iio_device_unregister(indio_dev);
> + ad_sd_cleanup_buffer_and_trigger(indio_dev);
> +
> + regulator_disable(st->reg);
> +
> + return 0;
> +}
> +
> +static const struct spi_device_id ad7780_id[] = {
> + {"ad7170", ID_AD7170},
> + {"ad7171", ID_AD7171},
> + {"ad7780", ID_AD7780},
> + {"ad7781", ID_AD7781},
> + {}
> +};
> +MODULE_DEVICE_TABLE(spi, ad7780_id);
> +
> +static struct spi_driver ad7780_driver = {
> + .driver = {
> + .name = "ad7780",
> + },
> + .probe = ad7780_probe,
> + .remove = ad7780_remove,
> + .id_table = ad7780_id,
> +};
> +module_spi_driver(ad7780_driver);
> +
> +MODULE_AUTHOR("Michael Hennerich <michael.henner...@analog.com>");
> +MODULE_DESCRIPTION("Analog Devices AD7780 and similar ADCs");
> +MODULE_LICENSE("GPL v2");
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