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>
---
Changes since v1:
* Fixed voltage scale
* Fixed spelling and whitespace errors
---
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..e937408
--- /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,
+ enum ad_sigma_delta_mode 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);
+ bool unipolar = !!(st->mode & AD7791_MODE_UNIPOLAR);
+ unsigned long long scale_pv;
+
+ 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_pv = 5850000000000ULL;
+ } else {
+ int voltage_uv;
+
+ voltage_uv = regulator_get_voltage(st->reg);
+ if (voltage_uv < 0)
+ return voltage_uv;
+ scale_pv = (unsigned long long)voltage_uv * 1000000;
+ }
+ if (unipolar)
+ scale_pv >>= chan->scan_type.realbits;
+ else
+ scale_pv >>= chan->scan_type.realbits - 1;
+ *val2 = do_div(scale_pv, 1000000000);
+ *val = scale_pv;
+
+ 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",
+ [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)
+ 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..f9e4db1
--- /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.
+ * @burnout_current: If set to true the 100mA burnout current is enabled.
+ * @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
--
1.7.10.4
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