Re: [PATCH v5 3/3] iio: chemical: add Atlas pH-SM sensor support

[Jonathan Cameron <jic23@kernel.org>]

On 27/01/16 02:34, Matt Ranostay wrote:
> Add support for the Atlas Scientific pH-SM chemical sensor that can
> detect pH levels of solutions in the range of 0-14.
> 
> Signed-off-by: Matt Ranostay <mranostay@gmail.com>
Applied to the togreg branch of iio.git - initially pushed out as testing
for the autobuilders to play with it.

Thanks,

Jonathan
> ---
>  .../bindings/iio/chemical/atlas,ph-sm.txt          |  22 +
>  drivers/iio/chemical/Kconfig                       |  13 +
>  drivers/iio/chemical/Makefile                      |   1 +
>  drivers/iio/chemical/atlas-ph-sensor.c             | 511 +++++++++++++++++++++
>  4 files changed, 547 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/iio/chemical/atlas,ph-sm.txt
>  create mode 100644 drivers/iio/chemical/atlas-ph-sensor.c
> 
> diff --git a/Documentation/devicetree/bindings/iio/chemical/atlas,ph-sm.txt b/Documentation/devicetree/bindings/iio/chemical/atlas,ph-sm.txt
> new file mode 100644
> index 0000000..cffa190
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/chemical/atlas,ph-sm.txt
> @@ -0,0 +1,22 @@
> +* Atlas Scientific pH-SM OEM sensor
> +
> +http://www.atlas-scientific.com/_files/_datasheets/_oem/pH_oem_datasheet.pdf
> +
> +Required properties:
> +
> +  - compatible: must be "atlas,ph-sm"
> +  - reg: the I2C address of the sensor
> +  - interrupt-parent: should be the phandle for the interrupt controller
> +  - interrupts: the sole interrupt generated by the device
> +
> +  Refer to interrupt-controller/interrupts.txt for generic interrupt client
> +  node bindings.
> +
> +Example:
> +
> +atlas@65 {
> +	compatible = "atlas,ph-sm";
> +	reg = <0x65>;
> +	interrupt-parent = <&gpio1>;
> +	interrupts = <16 2>;
> +};
> diff --git a/drivers/iio/chemical/Kconfig b/drivers/iio/chemical/Kconfig
> index f16de61..ce7cd1370 100644
> --- a/drivers/iio/chemical/Kconfig
> +++ b/drivers/iio/chemical/Kconfig
> @@ -4,6 +4,19 @@
>  
>  menu "Chemical Sensors"
>  
> +config ATLAS_PH_SENSOR
> +	tristate "Atlas Scientific OEM pH-SM sensor"
> +	depends on I2C
> +	select REGMAP_I2C
> +	select IIO_BUFFER
> +	select IIO_TRIGGERED_BUFFER
> +	help
> +	 Say Y here to build I2C interface support for the Atlas
> +	 Scientific OEM pH-SM sensor.
> +
> +	 To compile this driver as module, choose M here: the
> +	 module will be called atlas-ph-sensor.
> +
>  config IAQCORE
>  	tristate "AMS iAQ-Core VOC sensors"
>  	depends on I2C
> diff --git a/drivers/iio/chemical/Makefile b/drivers/iio/chemical/Makefile
> index 167861f..b02202b 100644
> --- a/drivers/iio/chemical/Makefile
> +++ b/drivers/iio/chemical/Makefile
> @@ -3,5 +3,6 @@
>  #
>  
>  # When adding new entries keep the list in alphabetical order
> +obj-$(CONFIG_ATLAS_PH_SENSOR)	+= atlas-ph-sensor.o
>  obj-$(CONFIG_IAQCORE)		+= ams-iaq-core.o
>  obj-$(CONFIG_VZ89X)		+= vz89x.o
> diff --git a/drivers/iio/chemical/atlas-ph-sensor.c b/drivers/iio/chemical/atlas-ph-sensor.c
> new file mode 100644
> index 0000000..06cd49c
> --- /dev/null
> +++ b/drivers/iio/chemical/atlas-ph-sensor.c
> @@ -0,0 +1,511 @@
> +/*
> + * atlas-ph-sensor.c - Support for Atlas Scientific OEM pH-SM sensor
> + *
> + * Copyright (C) 2015 Matt Ranostay <mranostay@gmail.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/init.h>
> +#include <linux/interrupt.h>
> +#include <linux/delay.h>
> +#include <linux/mutex.h>
> +#include <linux/err.h>
> +#include <linux/irq.h>
> +#include <linux/irq_work.h>
> +#include <linux/gpio.h>
> +#include <linux/i2c.h>
> +#include <linux/regmap.h>
> +#include <linux/iio/iio.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/pm_runtime.h>
> +
> +#define ATLAS_REGMAP_NAME	"atlas_ph_regmap"
> +#define ATLAS_DRV_NAME		"atlas_ph"
> +
> +#define ATLAS_REG_DEV_TYPE		0x00
> +#define ATLAS_REG_DEV_VERSION		0x01
> +
> +#define ATLAS_REG_INT_CONTROL		0x04
> +#define ATLAS_REG_INT_CONTROL_EN	BIT(3)
> +
> +#define ATLAS_REG_PWR_CONTROL		0x06
> +
> +#define ATLAS_REG_CALIB_STATUS		0x0d
> +#define ATLAS_REG_CALIB_STATUS_MASK	0x07
> +#define ATLAS_REG_CALIB_STATUS_LOW	BIT(0)
> +#define ATLAS_REG_CALIB_STATUS_MID	BIT(1)
> +#define ATLAS_REG_CALIB_STATUS_HIGH	BIT(2)
> +
> +#define ATLAS_REG_TEMP_DATA		0x0e
> +#define ATLAS_REG_PH_DATA		0x16
> +
> +#define ATLAS_PH_INT_TIME_IN_US		450000
> +
> +struct atlas_data {
> +	struct i2c_client *client;
> +	struct iio_trigger *trig;
> +	struct regmap *regmap;
> +	struct irq_work work;
> +
> +	__be32 buffer[4]; /* 32-bit pH data + 32-bit pad + 64-bit timestamp */
> +};
> +
> +static const struct regmap_range atlas_volatile_ranges[] = {
> +	regmap_reg_range(ATLAS_REG_INT_CONTROL, ATLAS_REG_INT_CONTROL),
> +	regmap_reg_range(ATLAS_REG_CALIB_STATUS, ATLAS_REG_CALIB_STATUS),
> +	regmap_reg_range(ATLAS_REG_TEMP_DATA, ATLAS_REG_TEMP_DATA + 4),
> +	regmap_reg_range(ATLAS_REG_PH_DATA, ATLAS_REG_PH_DATA + 4),
> +};
> +
> +static const struct regmap_access_table atlas_volatile_table = {
> +	.yes_ranges	= atlas_volatile_ranges,
> +	.n_yes_ranges	= ARRAY_SIZE(atlas_volatile_ranges),
> +};
> +
> +static const struct regmap_config atlas_regmap_config = {
> +	.name = ATLAS_REGMAP_NAME,
> +
> +	.reg_bits = 8,
> +	.val_bits = 8,
> +
> +	.volatile_table = &atlas_volatile_table,
> +	.max_register = ATLAS_REG_PH_DATA + 4,
> +	.cache_type = REGCACHE_FLAT,
> +};
> +
> +static const struct iio_chan_spec atlas_channels[] = {
> +	{
> +		.type = IIO_PH,
> +		.info_mask_separate =
> +			BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
> +		.scan_index = 0,
> +		.scan_type = {
> +			.sign = 'u',
> +			.realbits = 32,
> +			.storagebits = 32,
> +			.endianness = IIO_BE,
> +		},
> +	},
> +	IIO_CHAN_SOFT_TIMESTAMP(1),
> +	{
> +		.type = IIO_TEMP,
> +		.address = ATLAS_REG_TEMP_DATA,
> +		.info_mask_separate =
> +			BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
> +		.output = 1,
> +		.scan_index = -1
> +	},
> +};
> +
> +static int atlas_set_powermode(struct atlas_data *data, int on)
> +{
> +	return regmap_write(data->regmap, ATLAS_REG_PWR_CONTROL, on);
> +}
> +
> +static int atlas_set_interrupt(struct atlas_data *data, bool state)
> +{
> +	return regmap_update_bits(data->regmap, ATLAS_REG_INT_CONTROL,
> +				  ATLAS_REG_INT_CONTROL_EN,
> +				  state ? ATLAS_REG_INT_CONTROL_EN : 0);
> +}
> +
> +static int atlas_buffer_postenable(struct iio_dev *indio_dev)
> +{
> +	struct atlas_data *data = iio_priv(indio_dev);
> +	int ret;
> +
> +	ret = iio_triggered_buffer_postenable(indio_dev);
> +	if (ret)
> +		return ret;
> +
> +	ret = pm_runtime_get_sync(&data->client->dev);
> +	if (ret < 0) {
> +		pm_runtime_put_noidle(&data->client->dev);
> +		return ret;
> +	}
> +
> +	return atlas_set_interrupt(data, true);
> +}
> +
> +static int atlas_buffer_predisable(struct iio_dev *indio_dev)
> +{
> +	struct atlas_data *data = iio_priv(indio_dev);
> +	int ret;
> +
> +	ret = iio_triggered_buffer_predisable(indio_dev);
> +	if (ret)
> +		return ret;
> +
> +	ret = atlas_set_interrupt(data, false);
> +	if (ret)
> +		return ret;
> +
> +	pm_runtime_mark_last_busy(&data->client->dev);
> +	return pm_runtime_put_autosuspend(&data->client->dev);
> +}
> +
> +static const struct iio_trigger_ops atlas_interrupt_trigger_ops = {
> +	.owner = THIS_MODULE,
> +};
> +
> +static const struct iio_buffer_setup_ops atlas_buffer_setup_ops = {
> +	.postenable = atlas_buffer_postenable,
> +	.predisable = atlas_buffer_predisable,
> +};
> +
> +static void atlas_work_handler(struct irq_work *work)
> +{
> +	struct atlas_data *data = container_of(work, struct atlas_data, work);
> +
> +	iio_trigger_poll(data->trig);
> +}
> +
> +static irqreturn_t atlas_trigger_handler(int irq, void *private)
> +{
> +	struct iio_poll_func *pf = private;
> +	struct iio_dev *indio_dev = pf->indio_dev;
> +	struct atlas_data *data = iio_priv(indio_dev);
> +	int ret;
> +
> +	ret = i2c_smbus_read_i2c_block_data(data->client, ATLAS_REG_PH_DATA,
> +				sizeof(data->buffer[0]), (u8 *) &data->buffer);
> +
> +	if (ret > 0)
> +		iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
> +				iio_get_time_ns());
> +
> +	iio_trigger_notify_done(indio_dev->trig);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static irqreturn_t atlas_interrupt_handler(int irq, void *private)
> +{
> +	struct iio_dev *indio_dev = private;
> +	struct atlas_data *data = iio_priv(indio_dev);
> +
> +	irq_work_queue(&data->work);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int atlas_read_ph_measurement(struct atlas_data *data, __be32 *val)
> +{
> +	struct device *dev = &data->client->dev;
> +	int suspended = pm_runtime_suspended(dev);
> +	int ret;
> +
> +	ret = pm_runtime_get_sync(dev);
> +	if (ret < 0) {
> +		pm_runtime_put_noidle(dev);
> +		return ret;
> +	}
> +
> +	if (suspended)
> +		usleep_range(ATLAS_PH_INT_TIME_IN_US,
> +			     ATLAS_PH_INT_TIME_IN_US + 100000);
> +
> +	ret = regmap_bulk_read(data->regmap, ATLAS_REG_PH_DATA,
> +			      (u8 *) val, sizeof(*val));
> +
> +	pm_runtime_mark_last_busy(dev);
> +	pm_runtime_put_autosuspend(dev);
> +
> +	return ret;
> +}
> +
> +static int atlas_read_raw(struct iio_dev *indio_dev,
> +			  struct iio_chan_spec const *chan,
> +			  int *val, int *val2, long mask)
> +{
> +	struct atlas_data *data = iio_priv(indio_dev);
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_RAW: {
> +		int ret;
> +		__be32 reg;
> +
> +		switch (chan->type) {
> +		case IIO_TEMP:
> +			ret = regmap_bulk_read(data->regmap, chan->address,
> +					      (u8 *) &reg, sizeof(reg));
> +			break;
> +		case IIO_PH:
> +			mutex_lock(&indio_dev->mlock);
> +
> +			if (iio_buffer_enabled(indio_dev))
> +				ret = -EBUSY;
> +			else
> +				ret = atlas_read_ph_measurement(data, &reg);
> +
> +			mutex_unlock(&indio_dev->mlock);
> +			break;
> +		default:
> +			ret = -EINVAL;
> +		}
> +
> +		if (!ret) {
> +			*val = be32_to_cpu(reg);
> +			ret = IIO_VAL_INT;
> +		}
> +		return ret;
> +	}
> +	case IIO_CHAN_INFO_SCALE:
> +		switch (chan->type) {
> +		case IIO_TEMP:
> +			*val = 1; /* 0.01 */
> +			*val2 = 100;
> +			break;
> +		case IIO_PH:
> +			*val = 1; /* 0.001 */
> +			*val2 = 1000;
> +			break;
> +		default:
> +			return -EINVAL;
> +		}
> +		return IIO_VAL_FRACTIONAL;
> +	}
> +
> +	return -EINVAL;
> +}
> +
> +static int atlas_write_raw(struct iio_dev *indio_dev,
> +			   struct iio_chan_spec const *chan,
> +			   int val, int val2, long mask)
> +{
> +	struct atlas_data *data = iio_priv(indio_dev);
> +	__be32 reg = cpu_to_be32(val);
> +
> +	if (val2 != 0 || val < 0 || val > 20000)
> +		return -EINVAL;
> +
> +	if (mask != IIO_CHAN_INFO_RAW || chan->type != IIO_TEMP)
> +		return -EINVAL;
> +
> +	return regmap_bulk_write(data->regmap, chan->address,
> +				 &reg, sizeof(reg));
> +}
> +
> +static const struct iio_info atlas_info = {
> +	.driver_module = THIS_MODULE,
> +	.read_raw = atlas_read_raw,
> +	.write_raw = atlas_write_raw,
> +};
> +
> +static int atlas_check_calibration(struct atlas_data *data)
> +{
> +	struct device *dev = &data->client->dev;
> +	int ret;
> +	unsigned int val;
> +
> +	ret = regmap_read(data->regmap, ATLAS_REG_CALIB_STATUS, &val);
> +	if (ret)
> +		return ret;
> +
> +	if (!(val & ATLAS_REG_CALIB_STATUS_MASK)) {
> +		dev_warn(dev, "device has not been calibrated\n");
> +		return 0;
> +	}
> +
> +	if (!(val & ATLAS_REG_CALIB_STATUS_LOW))
> +		dev_warn(dev, "device missing low point calibration\n");
> +
> +	if (!(val & ATLAS_REG_CALIB_STATUS_MID))
> +		dev_warn(dev, "device missing mid point calibration\n");
> +
> +	if (!(val & ATLAS_REG_CALIB_STATUS_HIGH))
> +		dev_warn(dev, "device missing high point calibration\n");
> +
> +	return 0;
> +};
> +
> +static int atlas_probe(struct i2c_client *client,
> +		       const struct i2c_device_id *id)
> +{
> +	struct atlas_data *data;
> +	struct iio_trigger *trig;
> +	struct iio_dev *indio_dev;
> +	int ret;
> +
> +	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
> +	if (!indio_dev)
> +		return -ENOMEM;
> +
> +	indio_dev->info = &atlas_info;
> +	indio_dev->name = ATLAS_DRV_NAME;
> +	indio_dev->channels = atlas_channels;
> +	indio_dev->num_channels = ARRAY_SIZE(atlas_channels);
> +	indio_dev->modes = INDIO_BUFFER_SOFTWARE | INDIO_DIRECT_MODE;
> +	indio_dev->dev.parent = &client->dev;
> +
> +	trig = devm_iio_trigger_alloc(&client->dev, "%s-dev%d",
> +				      indio_dev->name, indio_dev->id);
> +
> +	if (!trig)
> +		return -ENOMEM;
> +
> +	data = iio_priv(indio_dev);
> +	data->client = client;
> +	data->trig = trig;
> +	trig->dev.parent = indio_dev->dev.parent;
> +	trig->ops = &atlas_interrupt_trigger_ops;
> +	iio_trigger_set_drvdata(trig, indio_dev);
> +
> +	i2c_set_clientdata(client, indio_dev);
> +
> +	data->regmap = devm_regmap_init_i2c(client, &atlas_regmap_config);
> +	if (IS_ERR(data->regmap)) {
> +		dev_err(&client->dev, "regmap initialization failed\n");
> +		return PTR_ERR(data->regmap);
> +	}
> +
> +	ret = pm_runtime_set_active(&client->dev);
> +	if (ret)
> +		return ret;
> +
> +	if (client->irq <= 0) {
> +		dev_err(&client->dev, "no valid irq defined\n");
> +		return -EINVAL;
> +	}
> +
> +	ret = atlas_check_calibration(data);
> +	if (ret)
> +		return ret;
> +
> +	ret = iio_trigger_register(trig);
> +	if (ret) {
> +		dev_err(&client->dev, "failed to register trigger\n");
> +		return ret;
> +	}
> +
> +	ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
> +		&atlas_trigger_handler, &atlas_buffer_setup_ops);
> +	if (ret) {
> +		dev_err(&client->dev, "cannot setup iio trigger\n");
> +		goto unregister_trigger;
> +	}
> +
> +	init_irq_work(&data->work, atlas_work_handler);
> +
> +	/* interrupt pin toggles on new conversion */
> +	ret = devm_request_threaded_irq(&client->dev, client->irq,
> +					NULL, atlas_interrupt_handler,
> +					IRQF_TRIGGER_RISING |
> +					IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
> +					"atlas_irq",
> +					indio_dev);
> +	if (ret) {
> +		dev_err(&client->dev, "request irq (%d) failed\n", client->irq);
> +		goto unregister_buffer;
> +	}
> +
> +	ret = atlas_set_powermode(data, 1);
> +	if (ret) {
> +		dev_err(&client->dev, "cannot power device on");
> +		goto unregister_buffer;
> +	}
> +
> +	pm_runtime_enable(&client->dev);
> +	pm_runtime_set_autosuspend_delay(&client->dev, 2500);
> +	pm_runtime_use_autosuspend(&client->dev);
> +
> +	ret = iio_device_register(indio_dev);
> +	if (ret) {
> +		dev_err(&client->dev, "unable to register device\n");
> +		goto unregister_pm;
> +	}
> +
> +	return 0;
> +
> +unregister_pm:
> +	pm_runtime_disable(&client->dev);
> +	atlas_set_powermode(data, 0);
> +
> +unregister_buffer:
> +	iio_triggered_buffer_cleanup(indio_dev);
> +
> +unregister_trigger:
> +	iio_trigger_unregister(data->trig);
> +
> +	return ret;
> +}
> +
> +static int atlas_remove(struct i2c_client *client)
> +{
> +	struct iio_dev *indio_dev = i2c_get_clientdata(client);
> +	struct atlas_data *data = iio_priv(indio_dev);
> +
> +	iio_device_unregister(indio_dev);
> +	iio_triggered_buffer_cleanup(indio_dev);
> +	iio_trigger_unregister(data->trig);
> +
> +	pm_runtime_disable(&client->dev);
> +	pm_runtime_set_suspended(&client->dev);
> +	pm_runtime_put_noidle(&client->dev);
> +
> +	return atlas_set_powermode(data, 0);
> +}
> +
> +#ifdef CONFIG_PM
> +static int atlas_runtime_suspend(struct device *dev)
> +{
> +	struct atlas_data *data =
> +		     iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
> +
> +	return atlas_set_powermode(data, 0);
> +}
> +
> +static int atlas_runtime_resume(struct device *dev)
> +{
> +	struct atlas_data *data =
> +		     iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
> +
> +	return atlas_set_powermode(data, 1);
> +}
> +#endif
> +
> +static const struct dev_pm_ops atlas_pm_ops = {
> +	SET_RUNTIME_PM_OPS(atlas_runtime_suspend,
> +			   atlas_runtime_resume, NULL)
> +};
> +
> +static const struct i2c_device_id atlas_id[] = {
> +	{ "atlas-ph-sm", 0 },
> +	{}
> +};
> +MODULE_DEVICE_TABLE(i2c, atlas_id);
> +
> +static const struct of_device_id atlas_dt_ids[] = {
> +	{ .compatible = "atlas,ph-sm" },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(of, atlas_dt_ids);
> +
> +static struct i2c_driver atlas_driver = {
> +	.driver = {
> +		.name	= ATLAS_DRV_NAME,
> +		.of_match_table	= of_match_ptr(atlas_dt_ids),
> +		.pm	= &atlas_pm_ops,
> +	},
> +	.probe		= atlas_probe,
> +	.remove		= atlas_remove,
> +	.id_table	= atlas_id,
> +};
> +module_i2c_driver(atlas_driver);
> +
> +MODULE_AUTHOR("Matt Ranostay <mranostay@gmail.com>");
> +MODULE_DESCRIPTION("Atlas Scientific pH-SM sensor");
> +MODULE_LICENSE("GPL");
>