[RFC v2 0/3] iio: chemical: add Atlas pH-SM sensor support

[RFC v2 0/3] iio: chemical: add Atlas pH-SM sensor support

[Matt Ranostay]

Changes from v1:
* Add triggered buffer support 
* Rework runtime PM functionality
* Add more verbosity to the sysfs-bus-iio documentation
* Correct buffer size with padding bytes

IMPORTANT NOTE: Hasn't been tested on actual hardware yet

Matt Ranostay (3):
  devicetree: add Atlas Scientific LLC vendor prefix
  iio: ph: add IIO_PH channel type
  iio: chemical: add Atlas pH-SM sensor support

 Documentation/ABI/testing/sysfs-bus-iio            |   7 +
 .../bindings/iio/chemical/atlas,ph-sm.txt          |  22 ++
 .../devicetree/bindings/vendor-prefixes.txt        |   1 +
 drivers/iio/chemical/Kconfig                       |  13 +
 drivers/iio/chemical/Makefile                      |   1 +
 drivers/iio/chemical/atlas-ph-sensor.c             | 431 +++++++++++++++++++++
 drivers/iio/industrialio-core.c                    |   1 +
 include/uapi/linux/iio/types.h                     |   1 +
 8 files changed, 477 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/chemical/atlas,ph-sm.txt
 create mode 100644 drivers/iio/chemical/atlas-ph-sensor.c

-- 
1.9.1

[RFC v2 1/3] devicetree: add Atlas Scientific LLC vendor prefix

[Matt Ranostay]

Add the "atlas" vendor prefix for Atlas Scientific LLC

Signed-off-by: Matt Ranostay <mranostay@gmail.com>
---
 Documentation/devicetree/bindings/vendor-prefixes.txt | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Documentation/devicetree/bindings/vendor-prefixes.txt b/Documentation/devicetree/bindings/vendor-prefixes.txt
index 4e5603b..2245178 100644
--- a/Documentation/devicetree/bindings/vendor-prefixes.txt
+++ b/Documentation/devicetree/bindings/vendor-prefixes.txt
@@ -28,6 +28,7 @@ arm	ARM Ltd.
 armadeus	ARMadeus Systems SARL
 artesyn	Artesyn Embedded Technologies Inc.
 asahi-kasei	Asahi Kasei Corp.
+atlas	Atlas Scientific LLC
 atmel	Atmel Corporation
 auo	AU Optronics Corporation
 avago	Avago Technologies
-- 
1.9.1

[RFC v2 2/3] iio: ph: add IIO_PH channel type

[Matt Ranostay]

Signed-off-by: Matt Ranostay <mranostay@gmail.com>
---
 Documentation/ABI/testing/sysfs-bus-iio | 7 +++++++
 drivers/iio/industrialio-core.c         | 1 +
 include/uapi/linux/iio/types.h          | 1 +
 3 files changed, 9 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio
index 0439c2a..86ba8d6 100644
--- a/Documentation/ABI/testing/sysfs-bus-iio
+++ b/Documentation/ABI/testing/sysfs-bus-iio
@@ -1491,3 +1491,10 @@ Description:
 		This ABI is especially applicable for humidity sensors
 		to heatup the device and get rid of any condensation
 		in some humidity environment
+
+What:		/sys/bus/iio/devices/iio:deviceX/in_ph_raw
+KernelVersion:	4.5
+Contact:	linux-iio@vger.kernel.org
+Description:
+		Raw (unscaled no offset etc.) pH reading of a substance as a negative
+		base-10 logarithm of hydrodium ions in a litre of water.
diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index d42a8ff9..e1b9a9e 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -77,6 +77,7 @@ static const char * const iio_chan_type_name_spec[] = {
 	[IIO_VELOCITY] = "velocity",
 	[IIO_CONCENTRATION] = "concentration",
 	[IIO_RESISTANCE] = "resistance",
+	[IIO_PH] = "ph",
 };
 
 static const char * const iio_modifier_names[] = {
diff --git a/include/uapi/linux/iio/types.h b/include/uapi/linux/iio/types.h
index 7c63bd6..c077617 100644
--- a/include/uapi/linux/iio/types.h
+++ b/include/uapi/linux/iio/types.h
@@ -37,6 +37,7 @@ enum iio_chan_type {
 	IIO_VELOCITY,
 	IIO_CONCENTRATION,
 	IIO_RESISTANCE,
+	IIO_PH,
 };
 
 enum iio_modifier {
-- 
1.9.1

[RFC v2 3/3] iio: chemical: add Atlas pH-SM sensor support

[Matt Ranostay]

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>
---
 .../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             | 431 +++++++++++++++++++++
 4 files changed, 467 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 3061b72..a358e4b 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 VZ89X
 	tristate "SGX Sensortech MiCS VZ89X VOC sensor"
 	depends on I2C
diff --git a/drivers/iio/chemical/Makefile b/drivers/iio/chemical/Makefile
index 7292f2d..e9eb852 100644
--- a/drivers/iio/chemical/Makefile
+++ b/drivers/iio/chemical/Makefile
@@ -3,4 +3,5 @@
 #
 
 # When adding new entries keep the list in alphabetical order
+obj-$(CONFIG_ATLAS_PH_SENSOR)	+= atlas-ph-sensor.o
 obj-$(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..63da26b
--- /dev/null
+++ b/drivers/iio/chemical/atlas-ph-sensor.c
@@ -0,0 +1,431 @@
+/*
+ * 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/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(2)
+
+#define ATLAS_REG_PWR_CONTROL		0x06
+
+#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;
+
+	__be32 buffer[4]; /* 32-bit pH data + 32-bit pad + 64-bit timestamp */
+};
+
+static bool atlas_is_volatile_reg(struct device *dev, unsigned int reg)
+{
+	if (reg == ATLAS_REG_INT_CONTROL)
+		return true;
+
+	return false;
+}
+
+static const struct regmap_config atlas_regmap_config = {
+	.name = ATLAS_REGMAP_NAME,
+
+	.reg_bits = 8,
+	.val_bits = 8,
+
+	.volatile_reg = atlas_is_volatile_reg,
+	.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,
+		},
+	},
+	{
+		.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);
+
+	pm_runtime_get_sync(&data->client->dev);
+
+	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 = 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 irqreturn_t atlas_trigger_handler(int irq, void *private)
+{
+	struct iio_dev *indio_dev = private;
+	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);
+
+	/* re-enable interrupt */
+	atlas_set_interrupt(data, true);
+
+	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)
+		return ret;
+
+	if (suspended)
+		usleep_range(ATLAS_PH_INT_TIME_IN_US,
+			     ATLAS_PH_INT_TIME_IN_US + 100000);
+
+	ret = i2c_smbus_read_i2c_block_data(data->client, ATLAS_REG_PH_DATA,
+					    sizeof(*val), (u8 *) val);
+
+	pm_runtime_mark_last_busy(dev);
+	pm_runtime_put_autosuspend(dev);
+
+	return ret == sizeof(*val) ? 0 : -EINVAL;
+}
+
+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;
+
+		mutex_lock(&indio_dev->mlock);
+
+		if (iio_buffer_enabled(indio_dev)) {
+			ret = -EBUSY;
+			goto error_busy;
+		}
+
+		switch (chan->type) {
+		case IIO_TEMP:
+			ret = regmap_bulk_read(data->regmap, chan->address,
+					      (u8 *) &reg, sizeof(reg));
+			break;
+		case IIO_PH:
+			ret = atlas_read_ph_measurement(data, &reg);
+			break;
+		default:
+			ret = -EINVAL;
+		}
+
+		if (!ret) {
+			*val = be32_to_cpu(reg);
+			ret = IIO_VAL_INT;
+		}
+error_busy:
+		mutex_unlock(&indio_dev->mlock);
+		return ret;
+	}
+	case IIO_CHAN_INFO_SCALE:
+		*val = 0; /* 0.001 */
+		*val2 = 1000;
+		return IIO_VAL_INT_PLUS_MICRO;
+	}
+
+	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)
+		return -EINVAL;
+
+	if (mask != IIO_CHAN_INFO_RAW || chan->type != IIO_TEMP)
+		return -EINVAL;
+
+	return regmap_bulk_write(data->regmap, chan->address, &reg, 4);
+}
+
+static const struct iio_info atlas_info = {
+	.driver_module = THIS_MODULE,
+	.read_raw = atlas_read_raw,
+	.write_raw = atlas_write_raw,
+};
+
+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->modes = INDIO_BUFFER_SOFTWARE | INDIO_DIRECT_MODE;
+	indio_dev->setup_ops = &atlas_buffer_setup_ops;
+	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 = iio_trigger_register(trig);
+	if (ret) {
+		dev_err(&client->dev, "failed to register trigger\n");
+		return ret;
+	}
+
+	ret = iio_triggered_buffer_setup(indio_dev, NULL,
+		&atlas_trigger_handler, NULL);
+
+	if (ret) {
+		dev_err(&client->dev, "cannot setup iio trigger\n");
+		goto unregister_trigger;
+	}
+
+	ret = devm_request_threaded_irq(&client->dev, client->irq,
+					NULL, atlas_interrupt_handler,
+					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_buffer;
+	}
+
+	return 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");
-- 
1.9.1

Re: [RFC v2 3/3] iio: chemical: add Atlas pH-SM sensor support

[Adriana Reus]

On 15.12.2015 11:26, 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>
> ---
>   .../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             | 431 +++++++++++++++++++++
>   4 files changed, 467 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 3061b72..a358e4b 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 VZ89X
>   	tristate "SGX Sensortech MiCS VZ89X VOC sensor"
>   	depends on I2C
> diff --git a/drivers/iio/chemical/Makefile b/drivers/iio/chemical/Makefile
> index 7292f2d..e9eb852 100644
> --- a/drivers/iio/chemical/Makefile
> +++ b/drivers/iio/chemical/Makefile
> @@ -3,4 +3,5 @@
>   #
>
>   # When adding new entries keep the list in alphabetical order
> +obj-$(CONFIG_ATLAS_PH_SENSOR)	+= atlas-ph-sensor.o
>   obj-$(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..63da26b
> --- /dev/null
> +++ b/drivers/iio/chemical/atlas-ph-sensor.c
> @@ -0,0 +1,431 @@
> +/*
> + * 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/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(2)
> +
> +#define ATLAS_REG_PWR_CONTROL		0x06
> +
> +#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;
> +
> +	__be32 buffer[4]; /* 32-bit pH data + 32-bit pad + 64-bit timestamp */
> +};
> +
> +static bool atlas_is_volatile_reg(struct device *dev, unsigned int reg)
> +{
> +	if (reg == ATLAS_REG_INT_CONTROL)
> +		return true;
> +
> +	return false;
> +}
> +
> +static const struct regmap_config atlas_regmap_config = {
> +	.name = ATLAS_REGMAP_NAME,
> +
> +	.reg_bits = 8,
> +	.val_bits = 8,
> +
> +	.volatile_reg = atlas_is_volatile_reg,
> +	.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,
> +		},
> +	},
> +	{
> +		.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);
> +
> +	pm_runtime_get_sync(&data->client->dev);
^ pm_runtime_get_sync may return errors
> +
> +	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 = 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 irqreturn_t atlas_trigger_handler(int irq, void *private)
> +{
> +	struct iio_dev *indio_dev = private;
> +	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);
> +
> +	/* re-enable interrupt */
> +	atlas_set_interrupt(data, true);
> +
> +	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)
> +		return ret;
^ pm_runtime_get_sync can also return 1 (if the device is already
active).. in which case you definitely don't want to return here.
Also if this does return an error you may want to call put_noidle
because get_sync increments the device usage_count before it tries to
resume and you can end up with an unbalanced count there.
> +
> +	if (suspended)
> +		usleep_range(ATLAS_PH_INT_TIME_IN_US,
> +			     ATLAS_PH_INT_TIME_IN_US + 100000);
> +
> +	ret = i2c_smbus_read_i2c_block_data(data->client, ATLAS_REG_PH_DATA,
> +					    sizeof(*val), (u8 *) val);
> +
> +	pm_runtime_mark_last_busy(dev);
> +	pm_runtime_put_autosuspend(dev);
^ also may return err code
> +
> +	return ret == sizeof(*val) ? 0 : -EINVAL;
> +}
> +
> +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;
> +
> +		mutex_lock(&indio_dev->mlock);
> +
> +		if (iio_buffer_enabled(indio_dev)) {
> +			ret = -EBUSY;
> +			goto error_busy;
> +		}
> +
> +		switch (chan->type) {
> +		case IIO_TEMP:
> +			ret = regmap_bulk_read(data->regmap, chan->address,
> +					      (u8 *) &reg, sizeof(reg));
^ what would happen if temp is read while the chip is suspended
runtime-pm wise? Unless I am missing something the chip may be powered
off at this point.
> +			break;
> +		case IIO_PH:
> +			ret = atlas_read_ph_measurement(data, &reg);
> +			break;
> +		default:
> +			ret = -EINVAL;
> +		}
> +
> +		if (!ret) {
> +			*val = be32_to_cpu(reg);
> +			ret = IIO_VAL_INT;
> +		}
> +error_busy:
> +		mutex_unlock(&indio_dev->mlock);
> +		return ret;
> +	}
> +	case IIO_CHAN_INFO_SCALE:
> +		*val = 0; /* 0.001 */
> +		*val2 = 1000;
> +		return IIO_VAL_INT_PLUS_MICRO;
> +	}
> +
> +	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)
> +		return -EINVAL;
> +
> +	if (mask != IIO_CHAN_INFO_RAW || chan->type != IIO_TEMP)
> +		return -EINVAL;
> +
> +	return regmap_bulk_write(data->regmap, chan->address, &reg, 4);
> +}
> +
> +static const struct iio_info atlas_info = {
> +	.driver_module = THIS_MODULE,
> +	.read_raw = atlas_read_raw,
> +	.write_raw = atlas_write_raw,
> +};
> +
> +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->modes = INDIO_BUFFER_SOFTWARE | INDIO_DIRECT_MODE;
> +	indio_dev->setup_ops = &atlas_buffer_setup_ops;
> +	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 = iio_trigger_register(trig);
> +	if (ret) {
> +		dev_err(&client->dev, "failed to register trigger\n");
> +		return ret;
> +	}
> +
> +	ret = iio_triggered_buffer_setup(indio_dev, NULL,
> +		&atlas_trigger_handler, NULL);
> +
> +	if (ret) {
> +		dev_err(&client->dev, "cannot setup iio trigger\n");
> +		goto unregister_trigger;
> +	}
> +
> +	ret = devm_request_threaded_irq(&client->dev, client->irq,
> +					NULL, atlas_interrupt_handler,
> +					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_buffer;
> +	}
> +
> +	return 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");
>

Re: [RFC v2 3/3] iio: chemical: add Atlas pH-SM sensor support

[Matt Ranostay]

On Tue, Dec 15, 2015 at 3:03 AM, Adriana Reus <adriana.reus@intel.com> wrote:
>
>
> On 15.12.2015 11:26, 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>
>> ---
>>   .../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             | 431
>> +++++++++++++++++++++
>>   4 files changed, 467 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 3061b72..a358e4b 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 VZ89X
>>         tristate "SGX Sensortech MiCS VZ89X VOC sensor"
>>         depends on I2C
>> diff --git a/drivers/iio/chemical/Makefile b/drivers/iio/chemical/Makefile
>> index 7292f2d..e9eb852 100644
>> --- a/drivers/iio/chemical/Makefile
>> +++ b/drivers/iio/chemical/Makefile
>> @@ -3,4 +3,5 @@
>>   #
>>
>>   # When adding new entries keep the list in alphabetical order
>> +obj-$(CONFIG_ATLAS_PH_SENSOR)  += atlas-ph-sensor.o
>>   obj-$(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..63da26b
>> --- /dev/null
>> +++ b/drivers/iio/chemical/atlas-ph-sensor.c
>> @@ -0,0 +1,431 @@
>> +/*
>> + * 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/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(2)
>> +
>> +#define ATLAS_REG_PWR_CONTROL          0x06
>> +
>> +#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;
>> +
>> +       __be32 buffer[4]; /* 32-bit pH data + 32-bit pad + 64-bit
>> timestamp */
>> +};
>> +
>> +static bool atlas_is_volatile_reg(struct device *dev, unsigned int reg)
>> +{
>> +       if (reg == ATLAS_REG_INT_CONTROL)
>> +               return true;
>> +
>> +       return false;
>> +}
>> +
>> +static const struct regmap_config atlas_regmap_config = {
>> +       .name = ATLAS_REGMAP_NAME,
>> +
>> +       .reg_bits = 8,
>> +       .val_bits = 8,
>> +
>> +       .volatile_reg = atlas_is_volatile_reg,
>> +       .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,
>> +               },
>> +       },
>> +       {
>> +               .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);
>> +
>> +       pm_runtime_get_sync(&data->client->dev);
>
> ^ pm_runtime_get_sync may return errors

Noted.
>
>> +
>> +       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 = 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 irqreturn_t atlas_trigger_handler(int irq, void *private)
>> +{
>> +       struct iio_dev *indio_dev = private;
>> +       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);
>> +
>> +       /* re-enable interrupt */
>> +       atlas_set_interrupt(data, true);
>> +
>> +       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)
>> +               return ret;
>
> ^ pm_runtime_get_sync can also return 1 (if the device is already
> active).. in which case you definitely don't want to return here.
> Also if this does return an error you may want to call put_noidle
> because get_sync increments the device usage_count before it tries to
> resume and you can end up with an unbalanced count there.

Ok noted.

>>
>> +
>> +       if (suspended)
>> +               usleep_range(ATLAS_PH_INT_TIME_IN_US,
>> +                            ATLAS_PH_INT_TIME_IN_US + 100000);
>> +
>> +       ret = i2c_smbus_read_i2c_block_data(data->client,
>> ATLAS_REG_PH_DATA,
>> +                                           sizeof(*val), (u8 *) val);
>> +
>> +       pm_runtime_mark_last_busy(dev);
>> +       pm_runtime_put_autosuspend(dev);
>
> ^ also may return err code

Noted.
>
>> +
>> +       return ret == sizeof(*val) ? 0 : -EINVAL;
>> +}
>> +
>> +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;
>> +
>> +               mutex_lock(&indio_dev->mlock);
>> +
>> +               if (iio_buffer_enabled(indio_dev)) {
>> +                       ret = -EBUSY;
>> +                       goto error_busy;
>> +               }
>> +
>> +               switch (chan->type) {
>> +               case IIO_TEMP:
>> +                       ret = regmap_bulk_read(data->regmap,
>> chan->address,
>> +                                             (u8 *) &reg, sizeof(reg));
>
> ^ what would happen if temp is read while the chip is suspended
> runtime-pm wise? Unless I am missing something the chip may be powered
> off at this point.
>
Ah actually it is a "hibernate" mode in which samples aren't being
generated but i2c access is still up.
And this isn't a temperate reading from the sensor put one you pass to
it from a probe to adjust the pH reading calcualtion.

>> +                       break;
>> +               case IIO_PH:
>> +                       ret = atlas_read_ph_measurement(data, &reg);
>> +                       break;
>> +               default:
>> +                       ret = -EINVAL;
>> +               }
>> +
>> +               if (!ret) {
>> +                       *val = be32_to_cpu(reg);
>> +                       ret = IIO_VAL_INT;
>> +               }
>> +error_busy:
>> +               mutex_unlock(&indio_dev->mlock);
>> +               return ret;
>> +       }
>> +       case IIO_CHAN_INFO_SCALE:
>> +               *val = 0; /* 0.001 */
>> +               *val2 = 1000;
>> +               return IIO_VAL_INT_PLUS_MICRO;
>> +       }
>> +
>> +       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)
>> +               return -EINVAL;
>> +
>> +       if (mask != IIO_CHAN_INFO_RAW || chan->type != IIO_TEMP)
>> +               return -EINVAL;
>> +
>> +       return regmap_bulk_write(data->regmap, chan->address, &reg, 4);
>> +}
>> +
>> +static const struct iio_info atlas_info = {
>> +       .driver_module = THIS_MODULE,
>> +       .read_raw = atlas_read_raw,
>> +       .write_raw = atlas_write_raw,
>> +};
>> +
>> +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->modes = INDIO_BUFFER_SOFTWARE | INDIO_DIRECT_MODE;
>> +       indio_dev->setup_ops = &atlas_buffer_setup_ops;
>> +       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 = iio_trigger_register(trig);
>> +       if (ret) {
>> +               dev_err(&client->dev, "failed to register trigger\n");
>> +               return ret;
>> +       }
>> +
>> +       ret = iio_triggered_buffer_setup(indio_dev, NULL,
>> +               &atlas_trigger_handler, NULL);
>> +
>> +       if (ret) {
>> +               dev_err(&client->dev, "cannot setup iio trigger\n");
>> +               goto unregister_trigger;
>> +       }
>> +
>> +       ret = devm_request_threaded_irq(&client->dev, client->irq,
>> +                                       NULL, atlas_interrupt_handler,
>> +                                       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_buffer;
>> +       }
>> +
>> +       return 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");
>>
>

Re: [RFC v2 3/3] iio: chemical: add Atlas pH-SM sensor support

[Matt Ranostay]

On Tue, Dec 15, 2015 at 3:03 AM, Adriana Reus <adriana.reus@intel.com> wrote:
>
>
> On 15.12.2015 11:26, 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>
>> ---
>>   .../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             | 431
>> +++++++++++++++++++++
>>   4 files changed, 467 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 3061b72..a358e4b 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 VZ89X
>>         tristate "SGX Sensortech MiCS VZ89X VOC sensor"
>>         depends on I2C
>> diff --git a/drivers/iio/chemical/Makefile b/drivers/iio/chemical/Makefile
>> index 7292f2d..e9eb852 100644
>> --- a/drivers/iio/chemical/Makefile
>> +++ b/drivers/iio/chemical/Makefile
>> @@ -3,4 +3,5 @@
>>   #
>>
>>   # When adding new entries keep the list in alphabetical order
>> +obj-$(CONFIG_ATLAS_PH_SENSOR)  += atlas-ph-sensor.o
>>   obj-$(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..63da26b
>> --- /dev/null
>> +++ b/drivers/iio/chemical/atlas-ph-sensor.c
>> @@ -0,0 +1,431 @@
>> +/*
>> + * 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/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(2)
>> +
>> +#define ATLAS_REG_PWR_CONTROL          0x06
>> +
>> +#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;
>> +
>> +       __be32 buffer[4]; /* 32-bit pH data + 32-bit pad + 64-bit
>> timestamp */
>> +};
>> +
>> +static bool atlas_is_volatile_reg(struct device *dev, unsigned int reg)
>> +{
>> +       if (reg == ATLAS_REG_INT_CONTROL)
>> +               return true;
>> +
>> +       return false;
>> +}
>> +
>> +static const struct regmap_config atlas_regmap_config = {
>> +       .name = ATLAS_REGMAP_NAME,
>> +
>> +       .reg_bits = 8,
>> +       .val_bits = 8,
>> +
>> +       .volatile_reg = atlas_is_volatile_reg,
>> +       .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,
>> +               },
>> +       },
>> +       {
>> +               .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);
>> +
>> +       pm_runtime_get_sync(&data->client->dev);
>
> ^ pm_runtime_get_sync may return errors
>
>> +
>> +       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 = 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 irqreturn_t atlas_trigger_handler(int irq, void *private)
>> +{
>> +       struct iio_dev *indio_dev = private;
>> +       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);
>> +
>> +       /* re-enable interrupt */
>> +       atlas_set_interrupt(data, true);
>> +
>> +       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)
>> +               return ret;
>
> ^ pm_runtime_get_sync can also return 1 (if the device is already
> active).. in which case you definitely don't want to return here.
> Also if this does return an error you may want to call put_noidle
> because get_sync increments the device usage_count before it tries to
> resume and you can end up with an unbalanced count there.
>>
>> +
>> +       if (suspended)
>> +               usleep_range(ATLAS_PH_INT_TIME_IN_US,
>> +                            ATLAS_PH_INT_TIME_IN_US + 100000);
>> +
>> +       ret = i2c_smbus_read_i2c_block_data(data->client,
>> ATLAS_REG_PH_DATA,
>> +                                           sizeof(*val), (u8 *) val);
>> +
>> +       pm_runtime_mark_last_busy(dev);
>> +       pm_runtime_put_autosuspend(dev);
>
> ^ also may return err code

What would be proper handling of it here though? *_put_noidle ?


>
>> +
>> +       return ret == sizeof(*val) ? 0 : -EINVAL;
>> +}
>> +
>> +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;
>> +
>> +               mutex_lock(&indio_dev->mlock);
>> +
>> +               if (iio_buffer_enabled(indio_dev)) {
>> +                       ret = -EBUSY;
>> +                       goto error_busy;
>> +               }
>> +
>> +               switch (chan->type) {
>> +               case IIO_TEMP:
>> +                       ret = regmap_bulk_read(data->regmap,
>> chan->address,
>> +                                             (u8 *) &reg, sizeof(reg));
>
> ^ what would happen if temp is read while the chip is suspended
> runtime-pm wise? Unless I am missing something the chip may be powered
> off at this point.
>
>> +                       break;
>> +               case IIO_PH:
>> +                       ret = atlas_read_ph_measurement(data, &reg);
>> +                       break;
>> +               default:
>> +                       ret = -EINVAL;
>> +               }
>> +
>> +               if (!ret) {
>> +                       *val = be32_to_cpu(reg);
>> +                       ret = IIO_VAL_INT;
>> +               }
>> +error_busy:
>> +               mutex_unlock(&indio_dev->mlock);
>> +               return ret;
>> +       }
>> +       case IIO_CHAN_INFO_SCALE:
>> +               *val = 0; /* 0.001 */
>> +               *val2 = 1000;
>> +               return IIO_VAL_INT_PLUS_MICRO;
>> +       }
>> +
>> +       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)
>> +               return -EINVAL;
>> +
>> +       if (mask != IIO_CHAN_INFO_RAW || chan->type != IIO_TEMP)
>> +               return -EINVAL;
>> +
>> +       return regmap_bulk_write(data->regmap, chan->address, &reg, 4);
>> +}
>> +
>> +static const struct iio_info atlas_info = {
>> +       .driver_module = THIS_MODULE,
>> +       .read_raw = atlas_read_raw,
>> +       .write_raw = atlas_write_raw,
>> +};
>> +
>> +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->modes = INDIO_BUFFER_SOFTWARE | INDIO_DIRECT_MODE;
>> +       indio_dev->setup_ops = &atlas_buffer_setup_ops;
>> +       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 = iio_trigger_register(trig);
>> +       if (ret) {
>> +               dev_err(&client->dev, "failed to register trigger\n");
>> +               return ret;
>> +       }
>> +
>> +       ret = iio_triggered_buffer_setup(indio_dev, NULL,
>> +               &atlas_trigger_handler, NULL);
>> +
>> +       if (ret) {
>> +               dev_err(&client->dev, "cannot setup iio trigger\n");
>> +               goto unregister_trigger;
>> +       }
>> +
>> +       ret = devm_request_threaded_irq(&client->dev, client->irq,
>> +                                       NULL, atlas_interrupt_handler,
>> +                                       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_buffer;
>> +       }
>> +
>> +       return 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");
>>
>

Re: [RFC v2 3/3] iio: chemical: add Atlas pH-SM sensor support

[Adriana Reus]

On 15.12.2015 17:19, Matt Ranostay wrote:
> On Tue, Dec 15, 2015 at 3:03 AM, Adriana Reus <adriana.reus@intel.com> wrote:
>>
>>
>> On 15.12.2015 11:26, 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>
>>> ---
>>>    .../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             | 431
>>> +++++++++++++++++++++
>>>    4 files changed, 467 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 3061b72..a358e4b 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 VZ89X
>>>          tristate "SGX Sensortech MiCS VZ89X VOC sensor"
>>>          depends on I2C
>>> diff --git a/drivers/iio/chemical/Makefile b/drivers/iio/chemical/Makefile
>>> index 7292f2d..e9eb852 100644
>>> --- a/drivers/iio/chemical/Makefile
>>> +++ b/drivers/iio/chemical/Makefile
>>> @@ -3,4 +3,5 @@
>>>    #
>>>
>>>    # When adding new entries keep the list in alphabetical order
>>> +obj-$(CONFIG_ATLAS_PH_SENSOR)  += atlas-ph-sensor.o
>>>    obj-$(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..63da26b
>>> --- /dev/null
>>> +++ b/drivers/iio/chemical/atlas-ph-sensor.c
>>> @@ -0,0 +1,431 @@
>>> +/*
>>> + * 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/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(2)
>>> +
>>> +#define ATLAS_REG_PWR_CONTROL          0x06
>>> +
>>> +#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;
>>> +
>>> +       __be32 buffer[4]; /* 32-bit pH data + 32-bit pad + 64-bit
>>> timestamp */
>>> +};
>>> +
>>> +static bool atlas_is_volatile_reg(struct device *dev, unsigned int reg)
>>> +{
>>> +       if (reg == ATLAS_REG_INT_CONTROL)
>>> +               return true;
>>> +
>>> +       return false;
>>> +}
>>> +
>>> +static const struct regmap_config atlas_regmap_config = {
>>> +       .name = ATLAS_REGMAP_NAME,
>>> +
>>> +       .reg_bits = 8,
>>> +       .val_bits = 8,
>>> +
>>> +       .volatile_reg = atlas_is_volatile_reg,
>>> +       .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,
>>> +               },
>>> +       },
>>> +       {
>>> +               .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);
>>> +
>>> +       pm_runtime_get_sync(&data->client->dev);
>>
>> ^ pm_runtime_get_sync may return errors
>>
>>> +
>>> +       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 = 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 irqreturn_t atlas_trigger_handler(int irq, void *private)
>>> +{
>>> +       struct iio_dev *indio_dev = private;
>>> +       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);
>>> +
>>> +       /* re-enable interrupt */
>>> +       atlas_set_interrupt(data, true);
>>> +
>>> +       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)
>>> +               return ret;
>>
>> ^ pm_runtime_get_sync can also return 1 (if the device is already
>> active).. in which case you definitely don't want to return here.
>> Also if this does return an error you may want to call put_noidle
>> because get_sync increments the device usage_count before it tries to
>> resume and you can end up with an unbalanced count there.
>>>
>>> +
>>> +       if (suspended)
>>> +               usleep_range(ATLAS_PH_INT_TIME_IN_US,
>>> +                            ATLAS_PH_INT_TIME_IN_US + 100000);
>>> +
>>> +       ret = i2c_smbus_read_i2c_block_data(data->client,
>>> ATLAS_REG_PH_DATA,
>>> +                                           sizeof(*val), (u8 *) val);
>>> +
>>> +       pm_runtime_mark_last_busy(dev);
>>> +       pm_runtime_put_autosuspend(dev);
>>
>> ^ also may return err code
>
> What would be proper handling of it here though? *_put_noidle ?

No need for *_put_noidle AFAICT in this case, so just returning the
error code should be ok.
>
>
>>
>>> +
>>> +       return ret == sizeof(*val) ? 0 : -EINVAL;
>>> +}
>>> +
>>> +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;
>>> +
>>> +               mutex_lock(&indio_dev->mlock);
>>> +
>>> +               if (iio_buffer_enabled(indio_dev)) {
>>> +                       ret = -EBUSY;
>>> +                       goto error_busy;
>>> +               }
>>> +
>>> +               switch (chan->type) {
>>> +               case IIO_TEMP:
>>> +                       ret = regmap_bulk_read(data->regmap,
>>> chan->address,
>>> +                                             (u8 *) &reg, sizeof(reg));
>>
>> ^ what would happen if temp is read while the chip is suspended
>> runtime-pm wise? Unless I am missing something the chip may be powered
>> off at this point.
>>
>>> +                       break;
>>> +               case IIO_PH:
>>> +                       ret = atlas_read_ph_measurement(data, &reg);
>>> +                       break;
>>> +               default:
>>> +                       ret = -EINVAL;
>>> +               }
>>> +
>>> +               if (!ret) {
>>> +                       *val = be32_to_cpu(reg);
>>> +                       ret = IIO_VAL_INT;
>>> +               }
>>> +error_busy:
>>> +               mutex_unlock(&indio_dev->mlock);
>>> +               return ret;
>>> +       }
>>> +       case IIO_CHAN_INFO_SCALE:
>>> +               *val = 0; /* 0.001 */
>>> +               *val2 = 1000;
>>> +               return IIO_VAL_INT_PLUS_MICRO;
>>> +       }
>>> +
>>> +       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)
>>> +               return -EINVAL;
>>> +
>>> +       if (mask != IIO_CHAN_INFO_RAW || chan->type != IIO_TEMP)
>>> +               return -EINVAL;
>>> +
>>> +       return regmap_bulk_write(data->regmap, chan->address, &reg, 4);
>>> +}
>>> +
>>> +static const struct iio_info atlas_info = {
>>> +       .driver_module = THIS_MODULE,
>>> +       .read_raw = atlas_read_raw,
>>> +       .write_raw = atlas_write_raw,
>>> +};
>>> +
>>> +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->modes = INDIO_BUFFER_SOFTWARE | INDIO_DIRECT_MODE;
>>> +       indio_dev->setup_ops = &atlas_buffer_setup_ops;
>>> +       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 = iio_trigger_register(trig);
>>> +       if (ret) {
>>> +               dev_err(&client->dev, "failed to register trigger\n");
>>> +               return ret;
>>> +       }
>>> +
>>> +       ret = iio_triggered_buffer_setup(indio_dev, NULL,
>>> +               &atlas_trigger_handler, NULL);
>>> +
>>> +       if (ret) {
>>> +               dev_err(&client->dev, "cannot setup iio trigger\n");
>>> +               goto unregister_trigger;
>>> +       }
>>> +
>>> +       ret = devm_request_threaded_irq(&client->dev, client->irq,
>>> +                                       NULL, atlas_interrupt_handler,
>>> +                                       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_buffer;
>>> +       }
>>> +
>>> +       return 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");
>>>
>>

Re: [RFC v2 3/3] iio: chemical: add Atlas pH-SM sensor support

[Jonathan Cameron]

On 15/12/15 09:26, 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>
Some totally nit picky bits inline..  (what can I say I was
reading it and didn't find anything else wrong :)

If you hadn't been respinning anyway I'd just have fixed them
up whilst applying.

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             | 431 +++++++++++++++++++++
>  4 files changed, 467 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 3061b72..a358e4b 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 VZ89X
>  	tristate "SGX Sensortech MiCS VZ89X VOC sensor"
>  	depends on I2C
> diff --git a/drivers/iio/chemical/Makefile b/drivers/iio/chemical/Makefile
> index 7292f2d..e9eb852 100644
> --- a/drivers/iio/chemical/Makefile
> +++ b/drivers/iio/chemical/Makefile
> @@ -3,4 +3,5 @@
>  #
>  
>  # When adding new entries keep the list in alphabetical order
> +obj-$(CONFIG_ATLAS_PH_SENSOR)	+= atlas-ph-sensor.o
>  obj-$(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..63da26b
> --- /dev/null
> +++ b/drivers/iio/chemical/atlas-ph-sensor.c
> @@ -0,0 +1,431 @@
> +/*
> + * 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.
> + *
No need for a blank line here.
> + */
> +
> +#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/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(2)
> +
> +#define ATLAS_REG_PWR_CONTROL		0x06
> +
> +#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;
> +
> +	__be32 buffer[4]; /* 32-bit pH data + 32-bit pad + 64-bit timestamp */
> +};
> +
> +static bool atlas_is_volatile_reg(struct device *dev, unsigned int reg)
> +{
> +	if (reg == ATLAS_REG_INT_CONTROL)
> +		return true;
> +
> +	return false;
> +}
> +
> +static const struct regmap_config atlas_regmap_config = {
> +	.name = ATLAS_REGMAP_NAME,
> +
> +	.reg_bits = 8,
> +	.val_bits = 8,
> +
> +	.volatile_reg = atlas_is_volatile_reg,
> +	.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,
> +		},
> +	},
> +	{
> +		.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);
> +
> +	pm_runtime_get_sync(&data->client->dev);
> +
> +	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 = 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 irqreturn_t atlas_trigger_handler(int irq, void *private)
> +{
> +	struct iio_dev *indio_dev = private;
> +	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);
> +
> +	/* re-enable interrupt */
> +	atlas_set_interrupt(data, true);
> +
> +	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)
> +		return ret;
> +
> +	if (suspended)
> +		usleep_range(ATLAS_PH_INT_TIME_IN_US,
> +			     ATLAS_PH_INT_TIME_IN_US + 100000);
> +
> +	ret = i2c_smbus_read_i2c_block_data(data->client, ATLAS_REG_PH_DATA,
> +					    sizeof(*val), (u8 *) val);
> +
> +	pm_runtime_mark_last_busy(dev);
> +	pm_runtime_put_autosuspend(dev);
> +
> +	return ret == sizeof(*val) ? 0 : -EINVAL;
> +}
> +
> +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;
> +
> +		mutex_lock(&indio_dev->mlock);
> +
> +		if (iio_buffer_enabled(indio_dev)) {
> +			ret = -EBUSY;
> +			goto error_busy;
> +		}
> +
> +		switch (chan->type) {
> +		case IIO_TEMP:
> +			ret = regmap_bulk_read(data->regmap, chan->address,
> +					      (u8 *) &reg, sizeof(reg));
> +			break;
> +		case IIO_PH:
> +			ret = atlas_read_ph_measurement(data, &reg);
> +			break;
> +		default:
> +			ret = -EINVAL;
> +		}
> +
> +		if (!ret) {
> +			*val = be32_to_cpu(reg);
> +			ret = IIO_VAL_INT;
> +		}
> +error_busy:
> +		mutex_unlock(&indio_dev->mlock);
> +		return ret;
> +	}
> +	case IIO_CHAN_INFO_SCALE:
> +		*val = 0; /* 0.001 */
> +		*val2 = 1000;
> +		return IIO_VAL_INT_PLUS_MICRO;
> +	}
> +
> +	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)
> +		return -EINVAL;
> +
> +	if (mask != IIO_CHAN_INFO_RAW || chan->type != IIO_TEMP)
> +		return -EINVAL;
> +
> +	return regmap_bulk_write(data->regmap, chan->address, &reg, 4);
> +}
> +
> +static const struct iio_info atlas_info = {
> +	.driver_module = THIS_MODULE,
> +	.read_raw = atlas_read_raw,
> +	.write_raw = atlas_write_raw,
> +};
> +
> +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->modes = INDIO_BUFFER_SOFTWARE | INDIO_DIRECT_MODE;
> +	indio_dev->setup_ops = &atlas_buffer_setup_ops;
> +	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 = iio_trigger_register(trig);
> +	if (ret) {
> +		dev_err(&client->dev, "failed to register trigger\n");
> +		return ret;
> +	}
> +
> +	ret = iio_triggered_buffer_setup(indio_dev, NULL,
> +		&atlas_trigger_handler, NULL);
Getting really fussy, but this blank line is I think inconsistent
with how you have spacing in the rest of this file!
> +
> +	if (ret) {
> +		dev_err(&client->dev, "cannot setup iio trigger\n");
> +		goto unregister_trigger;
> +	}
> +
> +	ret = devm_request_threaded_irq(&client->dev, client->irq,
> +					NULL, atlas_interrupt_handler,
> +					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_buffer;
> +	}
> +
> +	return 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");
> 

Re: [RFC v2 3/3] iio: chemical: add Atlas pH-SM sensor support

[Matt Ranostay]

Ok will fix these minor formatting issues. Will submit version 3 when
the actual hardware is tested after the holidays.

On Sat, Dec 19, 2015 at 8:37 AM, Jonathan Cameron <jic23@kernel.org> wrote:
> On 15/12/15 09:26, 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>
> Some totally nit picky bits inline..  (what can I say I was
> reading it and didn't find anything else wrong :)
>
> If you hadn't been respinning anyway I'd just have fixed them
> up whilst applying.
>
> 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             | 431 +++++++++++++++++++++
>>  4 files changed, 467 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 3061b72..a358e4b 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 VZ89X
>>       tristate "SGX Sensortech MiCS VZ89X VOC sensor"
>>       depends on I2C
>> diff --git a/drivers/iio/chemical/Makefile b/drivers/iio/chemical/Makefile
>> index 7292f2d..e9eb852 100644
>> --- a/drivers/iio/chemical/Makefile
>> +++ b/drivers/iio/chemical/Makefile
>> @@ -3,4 +3,5 @@
>>  #
>>
>>  # When adding new entries keep the list in alphabetical order
>> +obj-$(CONFIG_ATLAS_PH_SENSOR)        += atlas-ph-sensor.o
>>  obj-$(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..63da26b
>> --- /dev/null
>> +++ b/drivers/iio/chemical/atlas-ph-sensor.c
>> @@ -0,0 +1,431 @@
>> +/*
>> + * 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.
>> + *
> No need for a blank line here.
>> + */
>> +
>> +#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/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(2)
>> +
>> +#define ATLAS_REG_PWR_CONTROL                0x06
>> +
>> +#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;
>> +
>> +     __be32 buffer[4]; /* 32-bit pH data + 32-bit pad + 64-bit timestamp */
>> +};
>> +
>> +static bool atlas_is_volatile_reg(struct device *dev, unsigned int reg)
>> +{
>> +     if (reg == ATLAS_REG_INT_CONTROL)
>> +             return true;
>> +
>> +     return false;
>> +}
>> +
>> +static const struct regmap_config atlas_regmap_config = {
>> +     .name = ATLAS_REGMAP_NAME,
>> +
>> +     .reg_bits = 8,
>> +     .val_bits = 8,
>> +
>> +     .volatile_reg = atlas_is_volatile_reg,
>> +     .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,
>> +             },
>> +     },
>> +     {
>> +             .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);
>> +
>> +     pm_runtime_get_sync(&data->client->dev);
>> +
>> +     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 = 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 irqreturn_t atlas_trigger_handler(int irq, void *private)
>> +{
>> +     struct iio_dev *indio_dev = private;
>> +     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);
>> +
>> +     /* re-enable interrupt */
>> +     atlas_set_interrupt(data, true);
>> +
>> +     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)
>> +             return ret;
>> +
>> +     if (suspended)
>> +             usleep_range(ATLAS_PH_INT_TIME_IN_US,
>> +                          ATLAS_PH_INT_TIME_IN_US + 100000);
>> +
>> +     ret = i2c_smbus_read_i2c_block_data(data->client, ATLAS_REG_PH_DATA,
>> +                                         sizeof(*val), (u8 *) val);
>> +
>> +     pm_runtime_mark_last_busy(dev);
>> +     pm_runtime_put_autosuspend(dev);
>> +
>> +     return ret == sizeof(*val) ? 0 : -EINVAL;
>> +}
>> +
>> +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;
>> +
>> +             mutex_lock(&indio_dev->mlock);
>> +
>> +             if (iio_buffer_enabled(indio_dev)) {
>> +                     ret = -EBUSY;
>> +                     goto error_busy;
>> +             }
>> +
>> +             switch (chan->type) {
>> +             case IIO_TEMP:
>> +                     ret = regmap_bulk_read(data->regmap, chan->address,
>> +                                           (u8 *) &reg, sizeof(reg));
>> +                     break;
>> +             case IIO_PH:
>> +                     ret = atlas_read_ph_measurement(data, &reg);
>> +                     break;
>> +             default:
>> +                     ret = -EINVAL;
>> +             }
>> +
>> +             if (!ret) {
>> +                     *val = be32_to_cpu(reg);
>> +                     ret = IIO_VAL_INT;
>> +             }
>> +error_busy:
>> +             mutex_unlock(&indio_dev->mlock);
>> +             return ret;
>> +     }
>> +     case IIO_CHAN_INFO_SCALE:
>> +             *val = 0; /* 0.001 */
>> +             *val2 = 1000;
>> +             return IIO_VAL_INT_PLUS_MICRO;
>> +     }
>> +
>> +     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)
>> +             return -EINVAL;
>> +
>> +     if (mask != IIO_CHAN_INFO_RAW || chan->type != IIO_TEMP)
>> +             return -EINVAL;
>> +
>> +     return regmap_bulk_write(data->regmap, chan->address, &reg, 4);
>> +}
>> +
>> +static const struct iio_info atlas_info = {
>> +     .driver_module = THIS_MODULE,
>> +     .read_raw = atlas_read_raw,
>> +     .write_raw = atlas_write_raw,
>> +};
>> +
>> +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->modes = INDIO_BUFFER_SOFTWARE | INDIO_DIRECT_MODE;
>> +     indio_dev->setup_ops = &atlas_buffer_setup_ops;
>> +     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 = iio_trigger_register(trig);
>> +     if (ret) {
>> +             dev_err(&client->dev, "failed to register trigger\n");
>> +             return ret;
>> +     }
>> +
>> +     ret = iio_triggered_buffer_setup(indio_dev, NULL,
>> +             &atlas_trigger_handler, NULL);
> Getting really fussy, but this blank line is I think inconsistent
> with how you have spacing in the rest of this file!
>> +
>> +     if (ret) {
>> +             dev_err(&client->dev, "cannot setup iio trigger\n");
>> +             goto unregister_trigger;
>> +     }
>> +
>> +     ret = devm_request_threaded_irq(&client->dev, client->irq,
>> +                                     NULL, atlas_interrupt_handler,
>> +                                     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_buffer;
>> +     }
>> +
>> +     return 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");
>>
>