two minor comments below
> This patch adds support for the Analog Devices AD7787, AD7788, AD7789, AD7790
> and AD7791 Sigma Delta Analog-to-Digital converters.
>
> Signed-off-by: Lars-Peter Clausen <lars@xxxxxxxxxx>
> ---
> drivers/iio/adc/Kconfig | 12 +
> drivers/iio/adc/Makefile | 1 +
> drivers/iio/adc/ad7791.c | 460 ++++++++++++++++++++++++++++++++++
> include/linux/platform_data/ad7791.h | 17 ++
> 4 files changed, 490 insertions(+)
> create mode 100644 drivers/iio/adc/ad7791.c
> create mode 100644 include/linux/platform_data/ad7791.h
>
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> index a2c5071..d0ae71e 100644
> --- a/drivers/iio/adc/Kconfig
> +++ b/drivers/iio/adc/Kconfig
> @@ -18,6 +18,18 @@ config AD7266
> Say yes here to build support for Analog Devices AD7265 and AD7266
> ADCs.
>
> +config AD7791
> + tristate "Analog Devices AD7791 ADC driver"
> + depends on SPI
> + select AD_SIGMA_DELTA
> + help
> + Say yes here to build support for Analog Devices AD7787, AD7788, AD7789,
> + AD7790 and AD7791 SPI analog to digital converters (ADC). If unsure, say
> + N (but it is safe to say "Y").
> +
> + To compile this driver as a module, choose M here: the module will be
> + called ad7791.
> +
> config AT91_ADC
> tristate "Atmel AT91 ADC"
> depends on ARCH_AT91
> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
> index 5989356..f187ff6 100644
> --- a/drivers/iio/adc/Makefile
> +++ b/drivers/iio/adc/Makefile
> @@ -4,4 +4,5 @@
>
> obj-$(CONFIG_AD_SIGMA_DELTA) += ad_sigma_delta.o
> obj-$(CONFIG_AD7266) += ad7266.o
> +obj-$(CONFIG_AD7791) += ad7791.o
> obj-$(CONFIG_AT91_ADC) += at91_adc.o
> diff --git a/drivers/iio/adc/ad7791.c b/drivers/iio/adc/ad7791.c
> new file mode 100644
> index 0000000..56b9ffc
> --- /dev/null
> +++ b/drivers/iio/adc/ad7791.c
> @@ -0,0 +1,460 @@
> +/*
> + * AD7787/AD7788/AD7789/AD7790/AD7791 SPI ADC driver
> + *
> + * Copyright 2012 Analog Devices Inc.
> + * Author: Lars-Peter Clausen <lars@xxxxxxxxxx>
> + *
> + * Licensed under the GPL-2.
> + */
> +
> +#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/delay.h>
> +#include <linux/module.h>
> +
> +#include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>
> +#include <linux/iio/buffer.h>
> +#include <linux/iio/trigger.h>
> +#include <linux/iio/trigger_consumer.h>
> +#include <linux/iio/triggered_buffer.h>
> +#include <linux/iio/adc/ad_sigma_delta.h>
> +
> +#include <linux/platform_data/ad7791.h>
> +
> +#define AD7791_REG_COMM 0x0 /* For writes */
> +#define AD7791_REG_STATUS 0x0 /* For reads */
> +#define AD7791_REG_MODE 0x1
> +#define AD7791_REG_FILTER 0x2
> +#define AD7791_REG_DATA 0x3
> +
> +#define AD7791_MODE_CONTINUOUS 0x00
> +#define AD7791_MODE_SINGLE 0x02
> +#define AD7791_MODE_POWERDOWN 0x03
> +
> +#define AD7791_CH_AIN1P_AIN1N 0x00
> +#define AD7791_CH_AIN2 0x01
> +#define AD7791_CH_AIN1N_AIN1N 0x02
> +#define AD7791_CH_AVDD_MONITOR 0x03
> +
> +#define AD7791_FILTER_CLK_DIV_1 (0x0 << 4)
> +#define AD7791_FILTER_CLK_DIV_2 (0x1 << 4)
> +#define AD7791_FILTER_CLK_DIV_4 (0x2 << 4)
> +#define AD7791_FILTER_CLK_DIV_8 (0x3 << 4)
> +#define AD7791_FILTER_CLK_MASK (0x3 << 4)
> +#define AD7791_FILTER_RATE_120 0x0
> +#define AD7791_FILTER_RATE_100 0x1
> +#define AD7791_FILTER_RATE_33_3 0x2
> +#define AD7791_FILTER_RATE_20 0x3
> +#define AD7791_FILTER_RATE_16_6 0x4
> +#define AD7791_FILTER_RATE_16_7 0x5
> +#define AD7791_FILTER_RATE_13_3 0x6
> +#define AD7791_FILTER_RATE_9_5 0x7
> +#define AD7791_FILTER_RATE_MASK 0x7
> +
> +#define AD7791_MODE_BUFFER BIT(1)
> +#define AD7791_MODE_UNIPOLAR BIT(2)
> +#define AD7791_MODE_BURNOUT BIT(3)
> +#define AD7791_MODE_SEL_MASK (0x3 << 6)
> +#define AD7791_MODE_SEL(x) ((x) << 6)
> +
> +#define DECLARE_AD7787_CHANNELS(name, bits, storagebits) \
> +const struct iio_chan_spec name[] = { \
> + AD_SD_DIFF_CHANNEL(0, 0, 0, AD7791_CH_AIN1P_AIN1N, \
> + (bits), (storagebits), 0), \
> + AD_SD_CHANNEL(1, 1, AD7791_CH_AIN2, (bits), (storagebits), 0), \
> + AD_SD_SHORTED_CHANNEL(2, 0, AD7791_CH_AIN1N_AIN1N, \
> + (bits), (storagebits), 0), \
> + AD_SD_SUPPLY_CHANNEL(3, 2, AD7791_CH_AVDD_MONITOR, \
> + (bits), (storagebits), 0), \
> + IIO_CHAN_SOFT_TIMESTAMP(4), \
> +}
> +
> +#define DECLARE_AD7791_CHANNELS(name, bits, storagebits) \
> +const struct iio_chan_spec name[] = { \
> + AD_SD_DIFF_CHANNEL(0, 0, 0, AD7791_CH_AIN1P_AIN1N, \
> + (bits), (storagebits), 0), \
> + AD_SD_SHORTED_CHANNEL(1, 0, AD7791_CH_AIN1N_AIN1N, \
> + (bits), (storagebits), 0), \
> + AD_SD_SUPPLY_CHANNEL(2, 1, AD7791_CH_AVDD_MONITOR, \
> + (bits), (storagebits), 0), \
> + IIO_CHAN_SOFT_TIMESTAMP(3), \
> +}
> +
> +static DECLARE_AD7787_CHANNELS(ad7787_channels, 24, 32);
> +static DECLARE_AD7791_CHANNELS(ad7790_channels, 16, 16);
> +static DECLARE_AD7791_CHANNELS(ad7791_channels, 24, 32);
> +
> +enum {
> + AD7787,
> + AD7788,
> + AD7789,
> + AD7790,
> + AD7791,
> +};
> +
> +enum ad7791_chip_info_flags {
> + AD7791_FLAG_HAS_FILTER = (1 << 0),
> + AD7791_FLAG_HAS_BUFFER = (1 << 1),
> + AD7791_FLAG_HAS_UNIPOLAR = (1 << 2),
> + AD7791_FLAG_HAS_BURNOUT = (1 << 3),
> +};
> +
> +struct ad7791_chip_info {
> + const struct iio_chan_spec *channels;
> + unsigned int num_channels;
> + enum ad7791_chip_info_flags flags;
> +};
> +
> +static const struct ad7791_chip_info ad7791_chip_infos[] = {
> + [AD7787] = {
> + .channels = ad7787_channels,
> + .num_channels = ARRAY_SIZE(ad7787_channels),
> + .flags = AD7791_FLAG_HAS_FILTER | AD7791_FLAG_HAS_BUFFER |
> + AD7791_FLAG_HAS_UNIPOLAR | AD7791_FLAG_HAS_BURNOUT,
> + },
> + [AD7788] = {
> + .channels = ad7790_channels,
> + .num_channels = ARRAY_SIZE(ad7790_channels),
> + .flags = AD7791_FLAG_HAS_UNIPOLAR,
> + },
> + [AD7789] = {
> + .channels = ad7791_channels,
> + .num_channels = ARRAY_SIZE(ad7791_channels),
> + .flags = AD7791_FLAG_HAS_UNIPOLAR,
> + },
> + [AD7790] = {
> + .channels = ad7790_channels,
> + .num_channels = ARRAY_SIZE(ad7790_channels),
> + .flags = AD7791_FLAG_HAS_FILTER | AD7791_FLAG_HAS_BUFFER |
> + AD7791_FLAG_HAS_BURNOUT,
> + },
> + [AD7791] = {
> + .channels = ad7791_channels,
> + .num_channels = ARRAY_SIZE(ad7791_channels),
> + .flags = AD7791_FLAG_HAS_FILTER | AD7791_FLAG_HAS_BUFFER |
> + AD7791_FLAG_HAS_UNIPOLAR | AD7791_FLAG_HAS_BURNOUT,
> + },
> +};
> +
> +struct ad7791_state {
> + struct ad_sigma_delta sd;
> + uint8_t mode;
> + uint8_t filter;
> +
> + struct regulator *reg;
> + const struct ad7791_chip_info *info;
> +};
> +
> +static struct ad7791_state *ad_sigma_delta_to_ad7791(struct ad_sigma_delta *sd)
> +{
> + return container_of(sd, struct ad7791_state, sd);
> +}
> +
> +static int ad7791_set_channel(struct ad_sigma_delta *sd, unsigned int channel)
> +{
> + ad_sd_set_comm(sd, channel);
> +
> + return 0;
> +}
> +
> +static int ad7791_set_mode(struct ad_sigma_delta *sd, unsigned int mode)
> +{
> + struct ad7791_state *st = ad_sigma_delta_to_ad7791(sd);
> +
> + switch (mode) {
> + case AD_SD_MODE_CONTINUOUS:
> + mode = AD7791_MODE_CONTINUOUS;
> + break;
> + case AD_SD_MODE_SINGLE:
> + mode = AD7791_MODE_SINGLE;
> + break;
> + case AD_SD_MODE_IDLE:
> + case AD_SD_MODE_POWERDOWN:
> + mode = AD7791_MODE_POWERDOWN;
> + break;
> + }
> +
> + st->mode &= ~AD7791_MODE_SEL_MASK;
> + st->mode |= AD7791_MODE_SEL(mode);
> +
> + return ad_sd_write_reg(sd, AD7791_REG_MODE, sizeof(st->mode), st->mode);
> +}
> +
> +static const struct ad_sigma_delta_info ad7791_sigma_delta_info = {
> + .set_channel = ad7791_set_channel,
> + .set_mode = ad7791_set_mode,
> + .has_registers = true,
> + .addr_shift = 4,
> + .read_mask = BIT(3),
> +};
> +
> +static int ad7791_read_raw(struct iio_dev *indio_dev,
> + const struct iio_chan_spec *chan, int *val, int *val2, long info)
> +{
> + struct ad7791_state *st = iio_priv(indio_dev);
> + unsigned long long scale_nv;
> + bool unipolar = !!(st->mode & AD7791_MODE_UNIPOLAR);
> +
> + switch (info) {
> + case IIO_CHAN_INFO_RAW:
> + return ad_sigma_delta_single_conversion(indio_dev, chan, val);
> + case IIO_CHAN_INFO_OFFSET:
> + /**
> + * Unipolar: 0 to VREF
> + * Bipolar -VREF to VREF
> + **/
> + if (unipolar)
> + *val = 0;
> + else
> + *val = -(1 << (chan->scan_type.realbits - 1));
> + return IIO_VAL_INT;
> + case IIO_CHAN_INFO_SCALE:
> + /* The monitor channel uses an internal reference. */
> + if (chan->address == AD7791_CH_AVDD_MONITOR) {
> + scale_nv = 5850000000ULL;
> + } else {
> + int voltage_uv;
> +
> + voltage_uv = regulator_get_voltage(st->reg);
> + if (voltage_uv < 0)
> + return voltage_uv;
> + scale_nv = voltage_uv * 1000;
> + }
> + if (unipolar)
> + scale_nv >>= chan->scan_type.realbits;
> + else
> + scale_nv >>= chan->scan_type.realbits - 1;
> + *val2 = do_div(scale_nv, 1000000);
> + *val = scale_nv;
> +
> + return IIO_VAL_INT_PLUS_NANO;
> + }
> +
> + return -EINVAL;
> +}
> +
> +static const char * const ad7791_sample_freq_avail[] = {
> + [AD7791_FILTER_RATE_120] = "120",
> + [AD7791_FILTER_RATE_100] = "100",
> + [AD7791_FILTER_RATE_33_3] = "33.3",
> + [AD7791_FILTER_RATE_20] = "20",
> + [AD7791_FILTER_RATE_16_6] = "16.6",
> + [AD7791_FILTER_RATE_16_7] = "16.7",
just curious; why is this not in strictly decreasing order?
IIO_CONST_ATTR_SAMP_FREQ_AVAIL is...
> + [AD7791_FILTER_RATE_13_3] = "13.3",
> + [AD7791_FILTER_RATE_9_5] = "9.5",
> +};
> +
> +static ssize_t ad7791_read_frequency(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> + struct ad7791_state *st = iio_priv(indio_dev);
> + unsigned int rate = st->filter & AD7791_FILTER_RATE_MASK;
> +
> + return sprintf(buf, "%s\n", ad7791_sample_freq_avail[rate]);
> +}
> +
> +static ssize_t ad7791_write_frequency(struct device *dev,
> + struct device_attribute *attr, const char *buf, size_t len)
> +{
> + struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> + struct ad7791_state *st = iio_priv(indio_dev);
> + int i, ret;
> +
> + mutex_lock(&indio_dev->mlock);
> + if (iio_buffer_enabled(indio_dev)) {
> + mutex_unlock(&indio_dev->mlock);
> + return -EBUSY;
> + }
> + mutex_unlock(&indio_dev->mlock);
> +
> + ret = -EINVAL;
> +
> + for (i = 0; i < ARRAY_SIZE(ad7791_sample_freq_avail); i++) {
> + if (sysfs_streq(ad7791_sample_freq_avail[i], buf)) {
> +
> + mutex_lock(&indio_dev->mlock);
> + st->filter &= ~AD7791_FILTER_RATE_MASK;
> + st->filter |= i;
> + ad_sd_write_reg(&st->sd, AD7791_REG_FILTER,
> + sizeof(st->filter), st->filter);
> + mutex_unlock(&indio_dev->mlock);
> + ret = 0;
> + break;
> + }
> + }
> +
> + return ret ? ret : len;
> +}
> +
> +static IIO_DEV_ATTR_SAMP_FREQ(S_IWUSR | S_IRUGO,
> + ad7791_read_frequency,
> + ad7791_write_frequency);
> +
> +static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("120 100 33.3 20 16.7 16.6 13.3 9.5");
> +
> +static struct attribute *ad7791_attributes[] = {
> + &iio_dev_attr_sampling_frequency.dev_attr.attr,
> + &iio_const_attr_sampling_frequency_available.dev_attr.attr,
> + NULL
> +};
> +
> +static const struct attribute_group ad7791_attribute_group = {
> + .attrs = ad7791_attributes,
> +};
> +
> +static const struct iio_info ad7791_info = {
> + .read_raw = &ad7791_read_raw,
> + .attrs = &ad7791_attribute_group,
> + .validate_trigger = ad_sd_validate_trigger,
> + .driver_module = THIS_MODULE,
> +};
> +
> +static const struct iio_info ad7791_no_filter_info = {
> + .read_raw = &ad7791_read_raw,
> + .validate_trigger = ad_sd_validate_trigger,
> + .driver_module = THIS_MODULE,
> +};
> +
> +static int __devinit ad7791_setup(struct ad7791_state *st,
> + struct ad7791_platform_data *pdata)
> +{
> + /* Set to poweron-reset default values */
> + st->mode = AD7791_MODE_BUFFER;
> + st->filter = AD7791_FILTER_RATE_16_6;
> +
> + if (!pdata)
> + return 0;
> +
> + if ((st->info->flags & AD7791_FLAG_HAS_BUFFER) && !pdata->buffered)
there's one extra space before !pdata->buffered
> + st->mode &= ~AD7791_MODE_BUFFER;
> +
> + if ((st->info->flags & AD7791_FLAG_HAS_BURNOUT) &&
> + pdata->burnout_current)
> + st->mode |= AD7791_MODE_BURNOUT;
> +
> + if ((st->info->flags & AD7791_FLAG_HAS_UNIPOLAR) && pdata->unipolar)
> + st->mode |= AD7791_MODE_UNIPOLAR;
> +
> + return ad_sd_write_reg(&st->sd, AD7791_REG_MODE, sizeof(st->mode),
> + st->mode);
> +}
> +
> +static int __devinit ad7791_probe(struct spi_device *spi)
> +{
> + struct ad7791_platform_data *pdata = spi->dev.platform_data;
> + struct iio_dev *indio_dev;
> + struct ad7791_state *st;
> + int ret;
> +
> + if (!spi->irq) {
> + dev_err(&spi->dev, "Missing IRQ.\n");
> + return -ENXIO;
> + }
> +
> + indio_dev = iio_device_alloc(sizeof(*st));
> + if (!indio_dev)
> + return -ENOMEM;
> +
> + st = iio_priv(indio_dev);
> +
> + st->reg = regulator_get(&spi->dev, "refin");
> + if (IS_ERR(st->reg)) {
> + ret = PTR_ERR(st->reg);
> + goto err_iio_free;
> + }
> +
> + ret = regulator_enable(st->reg);
> + if (ret)
> + goto error_put_reg;
> +
> +
> + st->info = &ad7791_chip_infos[spi_get_device_id(spi)->driver_data];
> + ad_sd_init(&st->sd, indio_dev, spi, &ad7791_sigma_delta_info);
> +
> + 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->info->channels;
> + indio_dev->num_channels = st->info->num_channels;
> + if (st->info->flags & AD7791_FLAG_HAS_FILTER)
> + indio_dev->info = &ad7791_info;
> + else
> + indio_dev->info = &ad7791_no_filter_info;
> +
> + ret = ad_sd_setup_buffer_and_trigger(indio_dev);
> + if (ret)
> + goto error_disable_reg;
> +
> + ret = ad7791_setup(st, pdata);
> + if (ret)
> + goto error_remove_trigger;
> +
> + ret = iio_device_register(indio_dev);
> + if (ret)
> + goto error_remove_trigger;
> +
> + return 0;
> +
> +error_remove_trigger:
> + ad_sd_cleanup_buffer_and_trigger(indio_dev);
> +error_disable_reg:
> + regulator_disable(st->reg);
> +error_put_reg:
> + regulator_put(st->reg);
> +err_iio_free:
> + iio_device_free(indio_dev);
> +
> + return ret;
> +}
> +
> +static int __devexit ad7791_remove(struct spi_device *spi)
> +{
> + struct iio_dev *indio_dev = spi_get_drvdata(spi);
> + struct ad7791_state *st = iio_priv(indio_dev);
> +
> + iio_device_unregister(indio_dev);
> + ad_sd_cleanup_buffer_and_trigger(indio_dev);
> +
> + regulator_disable(st->reg);
> + regulator_put(st->reg);
> +
> + iio_device_free(indio_dev);
> +
> + return 0;
> +}
> +
> +static const struct spi_device_id ad7791_spi_ids[] = {
> + { "ad7787", AD7787 },
> + { "ad7788", AD7788 },
> + { "ad7789", AD7789 },
> + { "ad7790", AD7790 },
> + { "ad7791", AD7791 },
> + {}
> +};
> +MODULE_DEVICE_TABLE(spi, ad7791_spi_ids);
> +
> +static struct spi_driver ad7791_driver = {
> + .driver = {
> + .name = "ad7791",
> + .owner = THIS_MODULE,
> + },
> + .probe = ad7791_probe,
> + .remove = __devexit_p(ad7791_remove),
> + .id_table = ad7791_spi_ids,
> +};
> +module_spi_driver(ad7791_driver);
> +
> +MODULE_AUTHOR("Lars-Peter Clausen <lars@xxxxxxxxxx>");
> +MODULE_DESCRIPTION("Analog Device AD7787/AD7788/AD7789/AD7790/AD7791 ADC driver");
> +MODULE_LICENSE("GPL v2");
> diff --git a/include/linux/platform_data/ad7791.h b/include/linux/platform_data/ad7791.h
> new file mode 100644
> index 0000000..317881f
> --- /dev/null
> +++ b/include/linux/platform_data/ad7791.h
> @@ -0,0 +1,17 @@
> +#ifndef __LINUX_PLATFORM_DATA_AD7791__
> +#define __LINUX_PLATFORM_DATA_AD7791__
> +
> +/**
> + * struct ad7791_platform_data - AD7791 device platform data
> + * @buffered: If set to true configure the device for buffered input mode.
> + * @burnount_current: If set to true the 100mA burnout current is enabled.
burnout_current
> + * @unipolar: If set to true sample in unipolar mode, if set to false sample in
> + * bipolar mode.
> + */
> +struct ad7791_platform_data {
> + bool buffered;
> + bool burnout_current;
> + bool unipolar;
> +};
> +
> +#endif
>
--
Peter Meerwald
+43-664-2444418 (mobile)
--
To unsubscribe from this list: send the line "unsubscribe linux-iio" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
