Re: [PATCH v2 1/4] iio: adc: Add support for AD7091R5 ADC

From: Jonathan Cameron
Date: Sun Dec 01 2019 - 05:15:04 EST


On Mon, 25 Nov 2019 11:26:27 +0000
"Ardelean, Alexandru" <alexandru.Ardelean@xxxxxxxxxx> wrote:

> On Tue, 2019-10-29 at 18:29 +0200, Beniamin Bia wrote:
> > [External]
> >
> > From: Paul Cercueil <paul.cercueil@xxxxxxxxxx>
> >
> > AD7091 is 4-Channel, I2C, Ultra Low Power,12-Bit ADC.
> >
> > 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 v2:
> > -blank lines removed
> > -prefix added to macros
> > -comments rework
> > -error checking syntax changed
> > -iio mutex replaced by a mutex
> > -device remove function was removed and later replaced by devm_add_action
> > -regmap include removed from header
> >
> > drivers/iio/adc/Kconfig | 7 +
> > drivers/iio/adc/Makefile | 1 +
> > drivers/iio/adc/ad7091r-base.c | 264 +++++++++++++++++++++++++++++++++
> > drivers/iio/adc/ad7091r-base.h | 25 ++++
> > drivers/iio/adc/ad7091r5.c | 102 +++++++++++++
> > 5 files changed, 399 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.
> > +
>
> Sorry for the lateness here.
> Is it too late to mention to put this before the AD7124 driver?
> Same question for Makefile.

Good spot, but at this stage please send a follow up patch
tidying the ordering up.

Thanks,

Jonathan

>
> This is to keep things alphabetically sorted.
>
> Thanks
> Alex
>
> > 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..c2500f614d54
> > --- /dev/null
> > +++ b/drivers/iio/adc/ad7091r-base.c
> > @@ -0,0 +1,264 @@
> > +// 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;
> > +};
> > +
> > +static int ad7091r_set_mode(struct ad7091r_state *st, enum ad7091r_mode
> > mode)
> > +{
> > + int ret;
> > +
> > + switch (mode) {
> > + case AD7091R_MODE_SAMPLE:
> > + ret = regmap_update_bits(st->map, AD7091R_REG_CONF,
> > + AD7091R_REG_CONF_MODE_MASK, 0);
> > + break;
> > + case AD7091R_MODE_COMMAND:
> > + ret = regmap_update_bits(st->map, AD7091R_REG_CONF,
> > + AD7091R_REG_CONF_MODE_MASK,
> > + AD7091R_REG_CONF_CMD);
> > + break;
> > + case AD7091R_MODE_AUTOCYCLE:
> > + ret = regmap_update_bits(st->map, AD7091R_REG_CONF,
> > + AD7091R_REG_CONF_MODE_MASK,
> > + AD7091R_REG_CONF_AUTO);
> > + break;
> > + default:
> > + ret = -EINVAL;
> > + break;
> > + }
> > +
> > + if (ret)
> > + return ret;
> > +
> > + st->mode = mode;
> > +
> > + return ret;
> > +}
> > +
> > +static int ad7091r_set_channel(struct ad7091r_state *st, unsigned int
> > channel)
> > +{
> > + unsigned int foo;
> > + 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, &foo);
> > +}
> > +
> > +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 < 0)
> > + return ret;
> > +
> > + return iio_device_register(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..5f1147735953
> > --- /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_AD7091R5_BASE_H__ */
> > diff --git a/drivers/iio/adc/ad7091r5.c b/drivers/iio/adc/ad7091r5.c
> > new file mode 100644
> > index 000000000000..2c44dd02ba1a
> > --- /dev/null
> > +++ b/drivers/iio/adc/ad7091r5.c
> > @@ -0,0 +1,102 @@
> > +// 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),
> > +};
> > +#undef AD7091R_CHANNEL
> > +
> > +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 i2c_device_id ad7091r5_i2c_ids[] = {
> > + {"ad7091r5", 0},
> > + {}
> > +};
> > +MODULE_DEVICE_TABLE(i2c, ad7091r5_i2c_ids);
> > +
> > +static struct i2c_driver ad7091r5_driver = {
> > + .driver = {
> > + .name = "ad7091r5",
> > + },
> > + .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");