[PATCH v4 1/4] iio: adc: Add support for AD7091R5 ADC

From: Beniamin Bia
Date: Fri Nov 15 2019 - 07:23:24 EST

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From: Paul Cercueil <paul.cercueil@xxxxxxxxxx>

AD7091R5 is 4-Channel, I2C, Ultra Low Power,12-Bit ADC.

This driver will also support AD7091R2/4/8 in the future.

Datasheet:
Link: https://www.analog.com/media/en/technical-documentation/data-sheets/ad7091r-5.pdf

Signed-off-by: Paul Cercueil <paul.cercueil@xxxxxxxxxx>
Co-developed-by: Beniamin Bia <beniamin.bia@xxxxxxxxxx>
Signed-off-by: Beniamin Bia <beniamin.bia@xxxxxxxxxx>
---
Changes in v4:
-comment to specify mutex role
-return on error in set_mode
-int foo replaced by dummy
-undef channel removed
-device tree specific table added
-comment matches endif

drivers/iio/adc/Kconfig | 7 +
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/ad7091r-base.c | 260 +++++++++++++++++++++++++++++++++
drivers/iio/adc/ad7091r-base.h | 25 ++++
drivers/iio/adc/ad7091r5.c | 108 ++++++++++++++
5 files changed, 401 insertions(+)
create mode 100644 drivers/iio/adc/ad7091r-base.c
create mode 100644 drivers/iio/adc/ad7091r-base.h
create mode 100644 drivers/iio/adc/ad7091r5.c

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 7e3286265a38..80b1b9551749 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -22,6 +22,13 @@ config AD7124
To compile this driver as a module, choose M here: the module will be
called ad7124.

+config AD7091R5
+ tristate "Analog Devices AD7091R5 ADC Driver"
+ depends on I2C
+ select REGMAP_I2C
+ help
+ Say yes here to build support for Analog Devices AD7091R-5 ADC.
+
config AD7266
tristate "Analog Devices AD7265/AD7266 ADC driver"
depends on SPI_MASTER
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index ef9cc485fb67..55e44735aaac 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -6,6 +6,7 @@
# When adding new entries keep the list in alphabetical order
obj-$(CONFIG_AD_SIGMA_DELTA) += ad_sigma_delta.o
obj-$(CONFIG_AD7124) += ad7124.o
+obj-$(CONFIG_AD7091R5) += ad7091r5.o ad7091r-base.o
obj-$(CONFIG_AD7266) += ad7266.o
obj-$(CONFIG_AD7291) += ad7291.o
obj-$(CONFIG_AD7298) += ad7298.o
diff --git a/drivers/iio/adc/ad7091r-base.c b/drivers/iio/adc/ad7091r-base.c
new file mode 100644
index 000000000000..854de7c654c2
--- /dev/null
+++ b/drivers/iio/adc/ad7091r-base.c
@@ -0,0 +1,260 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * AD7091RX Analog to Digital converter driver
+ *
+ * Copyright 2014-2019 Analog Devices Inc.
+ */
+
+#include <linux/bitops.h>
+#include <linux/iio/events.h>
+#include <linux/iio/iio.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+
+#include "ad7091r-base.h"
+
+#define AD7091R_REG_RESULT 0
+#define AD7091R_REG_CHANNEL 1
+#define AD7091R_REG_CONF 2
+#define AD7091R_REG_ALERT 3
+#define AD7091R_REG_CH_LOW_LIMIT(ch) ((ch) * 3 + 4)
+#define AD7091R_REG_CH_HIGH_LIMIT(ch) ((ch) * 3 + 5)
+#define AD7091R_REG_CH_HYSTERESIS(ch) ((ch) * 3 + 6)
+
+/* AD7091R_REG_RESULT */
+#define AD7091R_REG_RESULT_CH_ID(x) (((x) >> 13) & 0x3)
+#define AD7091R_REG_RESULT_CONV_RESULT(x) ((x) & 0xfff)
+
+/* AD7091R_REG_CONF */
+#define AD7091R_REG_CONF_AUTO BIT(8)
+#define AD7091R_REG_CONF_CMD BIT(10)
+
+#define AD7091R_REG_CONF_MODE_MASK \
+ (AD7091R_REG_CONF_AUTO | AD7091R_REG_CONF_CMD)
+
+enum ad7091r_mode {
+ AD7091R_MODE_SAMPLE,
+ AD7091R_MODE_COMMAND,
+ AD7091R_MODE_AUTOCYCLE,
+};
+
+struct ad7091r_state {
+ struct device *dev;
+ struct regmap *map;
+ const struct ad7091r_chip_info *chip_info;
+ enum ad7091r_mode mode;
+ struct mutex lock; /*lock to prevent concurent reads */
+};
+
+static int ad7091r_set_mode(struct ad7091r_state *st, enum ad7091r_mode mode)
+{
+ int ret, conf;
+
+ switch (mode) {
+ case AD7091R_MODE_SAMPLE:
+ conf = 0;
+ break;
+ case AD7091R_MODE_COMMAND:
+ conf = AD7091R_REG_CONF_CMD;
+ break;
+ case AD7091R_MODE_AUTOCYCLE:
+ conf = AD7091R_REG_CONF_AUTO;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ ret = regmap_update_bits(st->map, AD7091R_REG_CONF,
+ AD7091R_REG_CONF_MODE_MASK, conf);
+ if (ret)
+ return ret;
+
+ st->mode = mode;
+
+ return 0;
+}
+
+static int ad7091r_set_channel(struct ad7091r_state *st, unsigned int channel)
+{
+ unsigned int dummy;
+ int ret;
+
+ /* AD7091R_REG_CHANNEL specified which channels to be converted */
+ ret = regmap_write(st->map, AD7091R_REG_CHANNEL,
+ BIT(channel) | (BIT(channel) << 8));
+ if (ret)
+ return ret;
+
+ /*
+ * There is a latency of one conversion before the channel conversion
+ * sequence is updated
+ */
+ return regmap_read(st->map, AD7091R_REG_RESULT, &dummy);
+}
+
+static int ad7091r_read_one(struct iio_dev *iio_dev,
+ unsigned int channel, unsigned int *read_val)
+{
+ struct ad7091r_state *st = iio_priv(iio_dev);
+ unsigned int val;
+ int ret;
+
+ ret = ad7091r_set_channel(st, channel);
+ if (ret)
+ return ret;
+
+ ret = regmap_read(st->map, AD7091R_REG_RESULT, &val);
+ if (ret)
+ return ret;
+
+ if (AD7091R_REG_RESULT_CH_ID(val) != channel)
+ return -EIO;
+
+ *read_val = AD7091R_REG_RESULT_CONV_RESULT(val);
+
+ return 0;
+}
+
+static int ad7091r_read_raw(struct iio_dev *iio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long m)
+{
+ struct ad7091r_state *st = iio_priv(iio_dev);
+ unsigned int read_val;
+ int ret;
+
+ mutex_lock(&st->lock);
+
+ switch (m) {
+ case IIO_CHAN_INFO_RAW:
+ if (st->mode != AD7091R_MODE_COMMAND) {
+ ret = -EBUSY;
+ goto unlock;
+ }
+
+ ret = ad7091r_read_one(iio_dev, chan->channel, &read_val);
+ if (ret)
+ goto unlock;
+
+ *val = read_val;
+ ret = IIO_VAL_INT;
+ break;
+
+ default:
+ ret = -EINVAL;
+ break;
+ }
+
+unlock:
+ mutex_unlock(&st->lock);
+ return ret;
+}
+
+static const struct iio_info ad7091r_info = {
+ .read_raw = ad7091r_read_raw,
+};
+
+static irqreturn_t ad7091r_event_handler(int irq, void *private)
+{
+ struct ad7091r_state *st = (struct ad7091r_state *) private;
+ struct iio_dev *iio_dev = dev_get_drvdata(st->dev);
+ unsigned int i, read_val;
+ int ret;
+ s64 timestamp = iio_get_time_ns(iio_dev);
+
+ ret = regmap_read(st->map, AD7091R_REG_ALERT, &read_val);
+ if (ret)
+ return IRQ_HANDLED;
+
+ for (i = 0; i < st->chip_info->num_channels; i++) {
+ if (read_val & BIT(i * 2))
+ iio_push_event(iio_dev,
+ IIO_UNMOD_EVENT_CODE(IIO_VOLTAGE, i,
+ IIO_EV_TYPE_THRESH,
+ IIO_EV_DIR_RISING), timestamp);
+ if (read_val & BIT(i * 2 + 1))
+ iio_push_event(iio_dev,
+ IIO_UNMOD_EVENT_CODE(IIO_VOLTAGE, i,
+ IIO_EV_TYPE_THRESH,
+ IIO_EV_DIR_FALLING), timestamp);
+ }
+
+ return IRQ_HANDLED;
+}
+
+int ad7091r_probe(struct device *dev, const char *name,
+ const struct ad7091r_chip_info *chip_info,
+ struct regmap *map, int irq)
+{
+ struct iio_dev *iio_dev;
+ struct ad7091r_state *st;
+ int ret;
+
+ iio_dev = devm_iio_device_alloc(dev, sizeof(*st));
+ if (!iio_dev)
+ return -ENOMEM;
+
+ st = iio_priv(iio_dev);
+ st->dev = dev;
+ st->chip_info = chip_info;
+ st->map = map;
+
+ iio_dev->dev.parent = dev;
+ iio_dev->name = name;
+ iio_dev->info = &ad7091r_info;
+ iio_dev->modes = INDIO_DIRECT_MODE;
+
+ iio_dev->num_channels = chip_info->num_channels;
+ iio_dev->channels = chip_info->channels;
+
+ if (irq) {
+ ret = devm_request_threaded_irq(dev, irq, NULL,
+ ad7091r_event_handler,
+ IRQF_TRIGGER_FALLING | IRQF_ONESHOT, name, st);
+ if (ret)
+ return ret;
+ }
+
+ /* Use command mode by default to convert only desired channels*/
+ ret = ad7091r_set_mode(st, AD7091R_MODE_COMMAND);
+ if (ret)
+ return ret;
+
+ return devm_iio_device_register(dev, iio_dev);
+}
+EXPORT_SYMBOL_GPL(ad7091r_probe);
+
+static bool ad7091r_writeable_reg(struct device *dev, unsigned int reg)
+{
+ switch (reg) {
+ case AD7091R_REG_RESULT:
+ case AD7091R_REG_ALERT:
+ return false;
+ default:
+ return true;
+ }
+}
+
+static bool ad7091r_volatile_reg(struct device *dev, unsigned int reg)
+{
+ switch (reg) {
+ case AD7091R_REG_RESULT:
+ case AD7091R_REG_ALERT:
+ return true;
+ default:
+ return false;
+ }
+}
+
+const struct regmap_config ad7091r_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 16,
+ .writeable_reg = ad7091r_writeable_reg,
+ .volatile_reg = ad7091r_volatile_reg,
+};
+EXPORT_SYMBOL_GPL(ad7091r_regmap_config);
+
+MODULE_AUTHOR("Beniamin Bia <beniamin.bia@xxxxxxxxxx>");
+MODULE_DESCRIPTION("Analog Devices AD7091Rx multi-channel converters");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/adc/ad7091r-base.h b/drivers/iio/adc/ad7091r-base.h
new file mode 100644
index 000000000000..b0b4fe01a681
--- /dev/null
+++ b/drivers/iio/adc/ad7091r-base.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * AD7091RX Analog to Digital converter driver
+ *
+ * Copyright 2014-2019 Analog Devices Inc.
+ */
+
+#ifndef __DRIVERS_IIO_ADC_AD7091R_BASE_H__
+#define __DRIVERS_IIO_ADC_AD7091R_BASE_H__
+
+struct device;
+struct ad7091r_state;
+
+struct ad7091r_chip_info {
+ unsigned int num_channels;
+ const struct iio_chan_spec *channels;
+};
+
+extern const struct regmap_config ad7091r_regmap_config;
+
+int ad7091r_probe(struct device *dev, const char *name,
+ const struct ad7091r_chip_info *chip_info,
+ struct regmap *map, int irq);
+
+#endif /* __DRIVERS_IIO_ADC_AD7091R_BASE_H__ */
diff --git a/drivers/iio/adc/ad7091r5.c b/drivers/iio/adc/ad7091r5.c
new file mode 100644
index 000000000000..30ff0108a6ed
--- /dev/null
+++ b/drivers/iio/adc/ad7091r5.c
@@ -0,0 +1,108 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * AD7091R5 Analog to Digital converter driver
+ *
+ * Copyright 2014-2019 Analog Devices Inc.
+ */
+
+#include <linux/i2c.h>
+#include <linux/iio/iio.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+
+#include "ad7091r-base.h"
+
+static const struct iio_event_spec ad7091r5_events[] = {
+ {
+ .type = IIO_EV_TYPE_THRESH,
+ .dir = IIO_EV_DIR_RISING,
+ .mask_separate = BIT(IIO_EV_INFO_VALUE) |
+ BIT(IIO_EV_INFO_ENABLE),
+ },
+ {
+ .type = IIO_EV_TYPE_THRESH,
+ .dir = IIO_EV_DIR_FALLING,
+ .mask_separate = BIT(IIO_EV_INFO_VALUE) |
+ BIT(IIO_EV_INFO_ENABLE),
+ },
+ {
+ .type = IIO_EV_TYPE_THRESH,
+ .dir = IIO_EV_DIR_EITHER,
+ .mask_separate = BIT(IIO_EV_INFO_HYSTERESIS),
+ },
+};
+
+#define AD7091R_CHANNEL(idx, bits, ev, num_ev) { \
+ .type = IIO_VOLTAGE, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .indexed = 1, \
+ .channel = idx, \
+ .event_spec = ev, \
+ .num_event_specs = num_ev, \
+}
+static const struct iio_chan_spec ad7091r5_channels_irq[] = {
+ AD7091R_CHANNEL(0, 12, ad7091r5_events, ARRAY_SIZE(ad7091r5_events)),
+ AD7091R_CHANNEL(1, 12, ad7091r5_events, ARRAY_SIZE(ad7091r5_events)),
+ AD7091R_CHANNEL(2, 12, ad7091r5_events, ARRAY_SIZE(ad7091r5_events)),
+ AD7091R_CHANNEL(3, 12, ad7091r5_events, ARRAY_SIZE(ad7091r5_events)),
+};
+
+static const struct iio_chan_spec ad7091r5_channels_noirq[] = {
+ AD7091R_CHANNEL(0, 12, NULL, 0),
+ AD7091R_CHANNEL(1, 12, NULL, 0),
+ AD7091R_CHANNEL(2, 12, NULL, 0),
+ AD7091R_CHANNEL(3, 12, NULL, 0),
+};
+
+static const struct ad7091r_chip_info ad7091r5_chip_info_irq = {
+ .channels = ad7091r5_channels_irq,
+ .num_channels = ARRAY_SIZE(ad7091r5_channels_irq),
+};
+
+static const struct ad7091r_chip_info ad7091r5_chip_info_noirq = {
+ .channels = ad7091r5_channels_noirq,
+ .num_channels = ARRAY_SIZE(ad7091r5_channels_noirq),
+};
+
+static int ad7091r5_i2c_probe(struct i2c_client *i2c,
+ const struct i2c_device_id *id)
+{
+ const struct ad7091r_chip_info *chip_info;
+ struct regmap *map = devm_regmap_init_i2c(i2c, &ad7091r_regmap_config);
+
+ if (IS_ERR(map))
+ return PTR_ERR(map);
+
+ if (i2c->irq)
+ chip_info = &ad7091r5_chip_info_irq;
+ else
+ chip_info = &ad7091r5_chip_info_noirq;
+
+ return ad7091r_probe(&i2c->dev, id->name, chip_info, map, i2c->irq);
+}
+
+static const struct of_device_id ad7091r5_dt_ids[] = {
+ { .compatible = "adi,ad7091r5" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, ad7091r5_dt_ids);
+
+static const struct i2c_device_id ad7091r5_i2c_ids[] = {
+ {"ad7091r5", 0},
+ {}
+};
+MODULE_DEVICE_TABLE(i2c, ad7091r5_i2c_ids);
+
+static struct i2c_driver ad7091r5_driver = {
+ .driver = {
+ .name = "ad7091r5",
+ .of_match_table = ad7091r5_dt_ids,
+ },
+ .probe = ad7091r5_i2c_probe,
+ .id_table = ad7091r5_i2c_ids,
+};
+module_i2c_driver(ad7091r5_driver);
+
+MODULE_AUTHOR("Beniamin Bia <beniamin.bia@xxxxxxxxxx>");
+MODULE_DESCRIPTION("Analog Devices AD7091R5 multi-channel ADC driver");
+MODULE_LICENSE("GPL v2");
--
2.17.1

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