[PATCH 1/2] iio: add IIO_DISTANCE type

[PATCH 1/2] iio: add IIO_DISTANCE type

[Matt Ranostay]

Signed-off-by: Matt Ranostay <mranostay@gmail.com>
---
 drivers/iio/industrialio-core.c | 1 +
 include/linux/iio/types.h       | 1 +
 2 files changed, 2 insertions(+)

diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index acc911a..ac999ab 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -70,6 +70,7 @@ static const char * const iio_chan_type_name_spec[] = {
 	[IIO_CCT] = "cct",
 	[IIO_PRESSURE] = "pressure",
 	[IIO_HUMIDITYRELATIVE] = "humidityrelative",
+	[IIO_DISTANCE] = "distance",
 };
 
 static const char * const iio_modifier_names[] = {
diff --git a/include/linux/iio/types.h b/include/linux/iio/types.h
index 084d882..675c2d8 100644
--- a/include/linux/iio/types.h
+++ b/include/linux/iio/types.h
@@ -30,6 +30,7 @@ enum iio_chan_type {
 	IIO_CCT,
 	IIO_PRESSURE,
 	IIO_HUMIDITYRELATIVE,
+	IIO_DISTANCE,
 };
 
 enum iio_modifier {
-- 
1.8.3.2

[PATCH 2/2] iio: Add AS3935 lightning sensor support

[Matt Ranostay]

AS3935 chipset can detect lightning strikes and reports those
back as events and the esimated distance to the storm.

Signed-off-by: Matt Ranostay <mranostay@gmail.com>
---
 .../devicetree/bindings/iio/distance/as3935.txt    |  25 ++
 drivers/iio/Kconfig                                |   1 +
 drivers/iio/Makefile                               |   1 +
 drivers/iio/distance/Kconfig                       |  19 +
 drivers/iio/distance/Makefile                      |   6 +
 drivers/iio/distance/as3935.c                      | 459 +++++++++++++++++++++
 6 files changed, 511 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/distance/as3935.txt
 create mode 100644 drivers/iio/distance/Kconfig
 create mode 100644 drivers/iio/distance/Makefile
 create mode 100644 drivers/iio/distance/as3935.c

diff --git a/Documentation/devicetree/bindings/iio/distance/as3935.txt b/Documentation/devicetree/bindings/iio/distance/as3935.txt
new file mode 100644
index 0000000..af35827
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/distance/as3935.txt
@@ -0,0 +1,25 @@
+Austrian Microsystems AS3935 Franklin lightning sensor device driver
+
+Required properties:
+	- compatible: must be "ams,as3935"
+	- reg: SPI chip select number for the device
+	- spi-max-frequency: Max SPI frequency to use
+	- spi-cpha: SPI Mode 1
+	- gpios: GPIO input of interrupt line from IRQ pin of AS3935 IC
+
+Optional properties:
+	- ams,tune-cap: Calibration tuning capacitor stepping value 0 - 15.
+	  Range of 0 to 120 pF, 8pF steps. This will require using the calibration
+	  data from the manufacturer.
+
+
+Example:
+
+		as3935@0 {
+			compatible = "ams,as3935";
+			reg = <0>;
+			spi-max-frequency = <100000>;
+			spi-cpha;
+			ams,tune-cap = /bits/ 8 <10>;
+			gpios = <&gpio1 16 10>;
+		};
diff --git a/drivers/iio/Kconfig b/drivers/iio/Kconfig
index 5dd0e12..5164a68 100644
--- a/drivers/iio/Kconfig
+++ b/drivers/iio/Kconfig
@@ -63,6 +63,7 @@ source "drivers/iio/adc/Kconfig"
 source "drivers/iio/amplifiers/Kconfig"
 source "drivers/iio/common/Kconfig"
 source "drivers/iio/dac/Kconfig"
+source "drivers/iio/distance/Kconfig"
 source "drivers/iio/frequency/Kconfig"
 source "drivers/iio/gyro/Kconfig"
 source "drivers/iio/humidity/Kconfig"
diff --git a/drivers/iio/Makefile b/drivers/iio/Makefile
index 887d390..1574731 100644
--- a/drivers/iio/Makefile
+++ b/drivers/iio/Makefile
@@ -16,6 +16,7 @@ obj-y += adc/
 obj-y += amplifiers/
 obj-y += common/
 obj-y += dac/
+obj-y += distance/
 obj-y += gyro/
 obj-y += frequency/
 obj-y += humidity/
diff --git a/drivers/iio/distance/Kconfig b/drivers/iio/distance/Kconfig
new file mode 100644
index 0000000..753352c
--- /dev/null
+++ b/drivers/iio/distance/Kconfig
@@ -0,0 +1,19 @@
+#
+# Distance sensors
+#
+
+menu "Lightning sensors"
+
+config AS3935
+	tristate "AS3935 Franklin lightning sensor"
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
+	depends on SPI
+	help
+	 If you say yes here you get support for the Austrian Microsystems
+	 AS3935 lightning detection sensor.
+
+	 This driver can also be built as a module. If so, the module
+	 will be called as3935
+
+endmenu
diff --git a/drivers/iio/distance/Makefile b/drivers/iio/distance/Makefile
new file mode 100644
index 0000000..f63b70d
--- /dev/null
+++ b/drivers/iio/distance/Makefile
@@ -0,0 +1,6 @@
+#
+# Makefile for IIO distance sensors
+#
+
+# When adding new entries keep the list in alphabetical order
+obj-$(CONFIG_AS3935)		+= as3935.o
diff --git a/drivers/iio/distance/as3935.c b/drivers/iio/distance/as3935.c
new file mode 100644
index 0000000..1a8f48d
--- /dev/null
+++ b/drivers/iio/distance/as3935.c
@@ -0,0 +1,459 @@
+/*
+ * as3935.c - Support for AS3935 Franklin lightning sensor
+ *
+ * Copyright (C) 2014 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/workqueue.h>
+#include <linux/err.h>
+#include <linux/irq.h>
+#include <linux/gpio.h>
+#include <linux/spi/spi.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/pinctrl/pinctrl.h>
+#include <linux/pinctrl/pinmux.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/pm_runtime.h>
+#include <linux/of_gpio.h>
+
+
+#define AS3935_AFE_GAIN		0x00
+#define AS3935_AFE_MASK		0x3F
+#define AS3935_AFE_GAIN_MAX	0x1F
+
+#define AS3935_INT		0x03
+#define AS3935_INT_MASK		0x07
+#define AS3935_DATA		0x07
+#define AS3935_DATA_MASK	0x1F
+
+#define AS3935_TUNE_CAP		0x08
+#define AS3935_CALIBRATE	0x3D
+
+#define AS3935_WRITE_DATA	(0x1 << 15)
+#define AS3935_READ_DATA	(0x1 << 14)
+#define AS3935_ADDRESS(x)	(x << 8)
+
+#define AS3935_EVENT_INT	(1<<3)
+#define AS3935_NOISE_INT	(1<<0)
+
+struct as3935_state {
+	struct spi_device *spi;
+	struct mutex lock;
+
+	struct iio_trigger *trig;
+	struct delayed_work work;
+
+	u8 tune_cap;
+};
+
+static const struct iio_chan_spec as3935_channels[] = {
+	{
+		.type           = IIO_DISTANCE,
+		.channel        = 0,
+		.info_mask_separate =
+			BIT(IIO_CHAN_INFO_RAW),
+		.scan_index     = 0,
+		.scan_type = {
+			.sign           = 'u',
+			.realbits       = 6,
+			.storagebits    = 6,
+		},
+		.modified = 0,
+	},
+	IIO_CHAN_SOFT_TIMESTAMP(1),
+};
+
+static const unsigned long as3935_available_scan_masks[] = { 0x01, 0x0 };
+
+static int as3935_read(struct as3935_state *st, unsigned int reg, int *val)
+{
+	u8 tx, rx;
+	int ret;
+
+	struct spi_transfer xfers[] = {
+		{
+			.tx_buf = &tx,
+			.bits_per_word = 8,
+			.len = 1,
+		}, {
+			.rx_buf = &rx,
+			.bits_per_word = 8,
+			.len = 1,
+		},
+	};
+
+	mutex_lock(&st->lock);
+	tx = (AS3935_READ_DATA | AS3935_ADDRESS(reg)) >> 8;
+
+	ret = spi_sync_transfer(st->spi, xfers, ARRAY_SIZE(xfers));
+	mutex_unlock(&st->lock);
+
+	*val = rx;
+
+	return ret;
+};
+
+static int as3935_write(struct as3935_state *st,
+				unsigned int reg,
+				unsigned int val)
+{
+	u8 buf[2];
+	int ret;
+
+	mutex_lock(&st->lock);
+	buf[0] = AS3935_WRITE_DATA | AS3935_ADDRESS(reg) >> 8;
+	buf[1] = val;
+
+	ret = spi_write(st->spi, (u8 *) &buf, 2);
+	mutex_unlock(&st->lock);
+
+	return ret;
+};
+
+static ssize_t gain_boost_show(struct device *dev,
+				struct device_attribute *attr,
+				char *buf)
+{
+	struct as3935_state *st = iio_priv(dev_to_iio_dev(dev));
+	int val, ret;
+
+	ret = as3935_read(st, AS3935_AFE_GAIN, &val);
+	if (ret)
+		return ret;
+	val = (val & AS3935_AFE_MASK) >> 1;
+
+	return sprintf(buf, "%d\n", val);
+};
+
+static ssize_t gain_boost_store(struct device *dev,
+					struct device_attribute *attr,
+					const char *buf, size_t len)
+{
+	struct as3935_state *st = iio_priv(dev_to_iio_dev(dev));
+	unsigned long val;
+	int ret;
+
+	ret = kstrtoul((const char *) buf, 10, &val);
+	if (ret)
+		return -EINVAL;
+
+	if (val > AS3935_AFE_GAIN_MAX)
+		return -EINVAL;
+
+	as3935_write(st, AS3935_AFE_GAIN, val << 1);
+
+	return len;
+};
+
+static IIO_DEVICE_ATTR(gain_boost, S_IRUGO | S_IWUSR,
+	gain_boost_show, gain_boost_store, 0);
+
+
+static struct attribute *as3935_attributes[] = {
+	&iio_dev_attr_gain_boost.dev_attr.attr,
+	NULL,
+};
+
+static struct attribute_group as3935_attribute_group = {
+	.attrs = as3935_attributes,
+};
+
+static int as3935_read_raw(struct iio_dev *indio_dev,
+			   struct iio_chan_spec const *chan,
+			   int *val,
+			   int *val2,
+			   long m)
+{
+	struct as3935_state *st = iio_priv(indio_dev);
+
+	if (m == IIO_CHAN_INFO_RAW) {
+		int ret;
+		*val = 0;
+		ret = as3935_read(st, AS3935_DATA, val2);
+		if (ret)
+			return ret;
+		return IIO_VAL_INT;
+	}
+
+	return -EINVAL;
+}
+
+static const struct iio_info as3935_info = {
+	.driver_module = THIS_MODULE,
+	.attrs = &as3935_attribute_group,
+	.read_raw = &as3935_read_raw,
+};
+
+static const struct iio_buffer_setup_ops iio_triggered_buffer_setup_ops = {
+	.postenable = &iio_triggered_buffer_postenable,
+	.predisable = &iio_triggered_buffer_predisable,
+};
+
+static irqreturn_t as3935_trigger_handler(int irq, void *private)
+{
+	struct iio_poll_func *pf = private;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct as3935_state *st = iio_priv(indio_dev);
+	int val, ret;
+
+	ret = as3935_read(st, AS3935_DATA, &val);
+	if (ret)
+		goto err_read;
+	val &= AS3935_DATA_MASK;
+	iio_push_to_buffers_with_timestamp(indio_dev, &val, iio_get_time_ns());
+
+	iio_trigger_notify_done(indio_dev->trig);
+err_read:
+
+	return IRQ_HANDLED;
+};
+
+static const struct iio_trigger_ops iio_interrupt_trigger_ops = {
+	.owner = THIS_MODULE,
+};
+
+static void as3935_event_work(struct work_struct *work)
+{
+	struct as3935_state *st;
+	struct spi_device *spi;
+	int val;
+
+	st = container_of(work, struct as3935_state, work.work);
+	spi = st->spi;
+
+	as3935_read(st, AS3935_INT, &val);
+	val &= AS3935_INT_MASK;
+
+	switch (val) {
+	case AS3935_EVENT_INT:
+		iio_trigger_poll(st->trig, 0);
+		break;
+	case AS3935_NOISE_INT:
+		dev_warn(&spi->dev, "noise level is too high");
+		break;
+	}
+};
+
+static irqreturn_t as3935_interrupt_handler(int irq, void *private)
+{
+	struct iio_dev *indio_dev = private;
+	struct as3935_state *st = iio_priv(indio_dev);
+
+	cancel_delayed_work(&st->work);
+	schedule_delayed_work(&st->work, jiffies_to_msecs(3));
+	return IRQ_HANDLED;
+}
+
+static void calibrate_as3935(struct as3935_state *st)
+{
+	/* mask disturber interrupt bit */
+	as3935_write(st, AS3935_INT, 1 << 5);
+
+	as3935_write(st, AS3935_CALIBRATE, 0x96);
+	as3935_write(st, AS3935_TUNE_CAP, 1 << 5 | st->tune_cap);
+
+	mdelay(2);
+	as3935_write(st, AS3935_TUNE_CAP, st->tune_cap);
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int as3935_suspend(struct spi_device *spi, pm_message_t msg)
+{
+	struct iio_dev *indio_dev = spi_get_drvdata(spi);
+	struct as3935_state *st = iio_priv(indio_dev);
+	int val, ret;
+
+	ret = as3935_read(st, AS3935_AFE_GAIN, &val);
+	if (ret)
+		return ret;
+	val |= 0x01;
+
+	return as3935_write(st, AS3935_AFE_GAIN, val);
+}
+
+static int as3935_resume(struct spi_device *spi)
+{
+	struct iio_dev *indio_dev = spi_get_drvdata(spi);
+	struct as3935_state *st = iio_priv(indio_dev);
+	int val, ret;
+
+	ret = as3935_read(st, AS3935_AFE_GAIN, &val);
+	if (ret)
+		return ret;
+	val &= ~1;
+
+	return as3935_write(st, AS3935_AFE_GAIN, val);
+}
+#else
+#define as3935_suspend	NULL
+#define as3935_resume	NULL
+#endif
+
+static int as3935_probe(struct spi_device *spi)
+{
+	struct iio_dev *indio_dev;
+	struct iio_trigger *trig;
+	struct as3935_state *st;
+	struct device_node *np = spi->dev.of_node;
+	int gpio;
+	int irq;
+	int ret;
+
+	/* Grab the GPIO to use for lightning event interrupt */
+	if (np)
+		gpio = of_get_gpio(spi->dev.of_node, 0);
+	else {
+		dev_err(&spi->dev, "unable to get interrupt gpio\n");
+		return -EINVAL;
+	}
+
+	/* GPIO event setup */
+	ret = devm_gpio_request(&spi->dev, gpio, "as3935");
+	if (ret) {
+		dev_err(&spi->dev, "failed to request GPIO %u\n", gpio);
+		return ret;
+	}
+
+	ret = gpio_direction_input(gpio);
+	if (ret) {
+		dev_err(&spi->dev, "failed to set pin direction\n");
+		return -EINVAL;
+	}
+
+	/* IRQ setup */
+	irq = gpio_to_irq(gpio);
+	if (irq < 0) {
+		dev_err(&spi->dev, "failed to map GPIO to IRQ: %d\n", irq);
+		return -EINVAL;
+	}
+
+	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(st));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	st = iio_priv(indio_dev);
+	st->spi = spi;
+	st->tune_cap = 0;
+	spi_set_drvdata(spi, indio_dev);
+	mutex_init(&st->lock);
+	INIT_DELAYED_WORK(&st->work, as3935_event_work);
+
+	of_property_read_u8(np, "ams,tune-cap", &st->tune_cap);
+	if (st->tune_cap > 15) {
+		dev_err(&spi->dev,
+			"wrong tune_cap setting of %d\n", st->tune_cap);
+		return -EINVAL;
+	}
+
+	indio_dev->dev.parent = &spi->dev;
+	indio_dev->name = spi_get_device_id(spi)->name;
+	indio_dev->channels = as3935_channels;
+	indio_dev->num_channels = ARRAY_SIZE(as3935_channels);
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->available_scan_masks = as3935_available_scan_masks;
+	indio_dev->info = &as3935_info;
+
+	trig = devm_iio_trigger_alloc(&spi->dev, "%s-dev%d",
+				      indio_dev->name, indio_dev->id);
+
+	if (!trig)
+		return -ENOMEM;
+
+	st->trig = trig;
+	trig->dev.parent = indio_dev->dev.parent;
+	iio_trigger_set_drvdata(trig, indio_dev);
+	trig->ops = &iio_interrupt_trigger_ops;
+
+	ret = iio_trigger_register(trig);
+	if (ret) {
+		dev_err(&spi->dev, "failed to register trigger\n");
+		return ret;
+	}
+
+	ret = iio_triggered_buffer_setup(indio_dev, NULL,
+					&as3935_trigger_handler,
+					&iio_triggered_buffer_setup_ops);
+
+	if (ret) {
+		dev_err(&spi->dev, "cannot setup iio trigger\n");
+		return -EINVAL;
+	}
+
+	calibrate_as3935(st);
+
+	ret = devm_request_irq(&spi->dev, irq,
+				&as3935_interrupt_handler,
+				IRQF_TRIGGER_RISING,
+				dev_name(&spi->dev),
+				indio_dev);
+
+	if (ret) {
+		dev_err(&spi->dev, "unable to request irq\n");
+		goto uninit_buffer;
+	}
+
+	ret = iio_device_register(indio_dev);
+	if (ret < 0) {
+		dev_err(&spi->dev, "unable to register device\n");
+		goto uninit_buffer;
+	}
+
+	return 0;
+
+uninit_buffer:
+	iio_triggered_buffer_cleanup(indio_dev);
+
+	return ret;
+};
+
+static int as3935_remove(struct spi_device *spi)
+{
+	struct iio_dev *indio_dev = spi_get_drvdata(spi);
+
+	iio_device_unregister(indio_dev);
+	return 0;
+};
+
+static const struct spi_device_id as3935_id[] = {
+	{"as3935", 0},
+	{},
+};
+MODULE_DEVICE_TABLE(spi, as3935_id);
+
+static struct spi_driver as3935_driver = {
+	.driver = {
+		.name	= "as3935",
+		.owner	= THIS_MODULE,
+	},
+	.probe		= as3935_probe,
+	.remove		= as3935_remove,
+	.id_table	= as3935_id,
+	.suspend	= as3935_suspend,
+	.resume		= as3935_resume,
+};
+module_spi_driver(as3935_driver);
+
+MODULE_AUTHOR("Matt Ranostay <mranostay@gmail.com>");
+MODULE_DESCRIPTION("AS3935 lightning sensor");
+MODULE_LICENSE("GPL");
-- 
1.8.3.2

Re: [PATCH 2/2] iio: Add AS3935 lightning sensor support

[Peter Meerwald]

> AS3935 chipset can detect lightning strikes and reports those
> back as events and the esimated distance to the storm.

pretty cool :)

the distance thing should be documented in 
Documentation/ABI/testing/sysfs-bus-iio -- which unit (meters?) for 
example

sysfs attributes such as boost should be documented as well; or better use 
a writable scale attribute if possible

nitpicking inline

> ---
>  .../devicetree/bindings/iio/distance/as3935.txt    |  25 ++
>  drivers/iio/Kconfig                                |   1 +
>  drivers/iio/Makefile                               |   1 +
>  drivers/iio/distance/Kconfig                       |  19 +
>  drivers/iio/distance/Makefile                      |   6 +
>  drivers/iio/distance/as3935.c                      | 459 +++++++++++++++++++++
>  6 files changed, 511 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/iio/distance/as3935.txt
>  create mode 100644 drivers/iio/distance/Kconfig
>  create mode 100644 drivers/iio/distance/Makefile
>  create mode 100644 drivers/iio/distance/as3935.c
> 
> diff --git a/Documentation/devicetree/bindings/iio/distance/as3935.txt b/Documentation/devicetree/bindings/iio/distance/as3935.txt
> new file mode 100644
> index 0000000..af35827
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/distance/as3935.txt
> @@ -0,0 +1,25 @@
> +Austrian Microsystems AS3935 Franklin lightning sensor device driver
> +
> +Required properties:
> +	- compatible: must be "ams,as3935"
> +	- reg: SPI chip select number for the device
> +	- spi-max-frequency: Max SPI frequency to use
> +	- spi-cpha: SPI Mode 1
> +	- gpios: GPIO input of interrupt line from IRQ pin of AS3935 IC
> +
> +Optional properties:
> +	- ams,tune-cap: Calibration tuning capacitor stepping value 0 - 15.
> +	  Range of 0 to 120 pF, 8pF steps. This will require using the calibration
> +	  data from the manufacturer.
> +
> +
> +Example:
> +
> +		as3935@0 {
> +			compatible = "ams,as3935";
> +			reg = <0>;
> +			spi-max-frequency = <100000>;
> +			spi-cpha;
> +			ams,tune-cap = /bits/ 8 <10>;
> +			gpios = <&gpio1 16 10>;
> +		};
> diff --git a/drivers/iio/Kconfig b/drivers/iio/Kconfig
> index 5dd0e12..5164a68 100644
> --- a/drivers/iio/Kconfig
> +++ b/drivers/iio/Kconfig
> @@ -63,6 +63,7 @@ source "drivers/iio/adc/Kconfig"
>  source "drivers/iio/amplifiers/Kconfig"
>  source "drivers/iio/common/Kconfig"
>  source "drivers/iio/dac/Kconfig"
> +source "drivers/iio/distance/Kconfig"
>  source "drivers/iio/frequency/Kconfig"
>  source "drivers/iio/gyro/Kconfig"
>  source "drivers/iio/humidity/Kconfig"
> diff --git a/drivers/iio/Makefile b/drivers/iio/Makefile
> index 887d390..1574731 100644
> --- a/drivers/iio/Makefile
> +++ b/drivers/iio/Makefile
> @@ -16,6 +16,7 @@ obj-y += adc/
>  obj-y += amplifiers/
>  obj-y += common/
>  obj-y += dac/
> +obj-y += distance/
>  obj-y += gyro/
>  obj-y += frequency/
>  obj-y += humidity/
> diff --git a/drivers/iio/distance/Kconfig b/drivers/iio/distance/Kconfig
> new file mode 100644
> index 0000000..753352c
> --- /dev/null
> +++ b/drivers/iio/distance/Kconfig
> @@ -0,0 +1,19 @@
> +#
> +# Distance sensors
> +#
> +
> +menu "Lightning sensors"
> +
> +config AS3935
> +	tristate "AS3935 Franklin lightning sensor"
> +	select IIO_BUFFER
> +	select IIO_TRIGGERED_BUFFER
> +	depends on SPI
> +	help
> +	 If you say yes here you get support for the Austrian Microsystems
> +	 AS3935 lightning detection sensor.
> +
> +	 This driver can also be built as a module. If so, the module
> +	 will be called as3935
> +
> +endmenu
> diff --git a/drivers/iio/distance/Makefile b/drivers/iio/distance/Makefile
> new file mode 100644
> index 0000000..f63b70d
> --- /dev/null
> +++ b/drivers/iio/distance/Makefile
> @@ -0,0 +1,6 @@
> +#
> +# Makefile for IIO distance sensors
> +#
> +
> +# When adding new entries keep the list in alphabetical order
> +obj-$(CONFIG_AS3935)		+= as3935.o
> diff --git a/drivers/iio/distance/as3935.c b/drivers/iio/distance/as3935.c
> new file mode 100644
> index 0000000..1a8f48d
> --- /dev/null
> +++ b/drivers/iio/distance/as3935.c
> @@ -0,0 +1,459 @@
> +/*
> + * as3935.c - Support for AS3935 Franklin lightning sensor
> + *
> + * Copyright (C) 2014 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/workqueue.h>
> +#include <linux/err.h>
> +#include <linux/irq.h>
> +#include <linux/gpio.h>
> +#include <linux/spi/spi.h>
> +#include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>
> +#include <linux/iio/trigger.h>
> +#include <linux/iio/trigger_consumer.h>
> +#include <linux/iio/buffer.h>
> +#include <linux/iio/triggered_buffer.h>
> +#include <linux/pinctrl/pinctrl.h>
> +#include <linux/pinctrl/pinmux.h>
> +#include <linux/pinctrl/consumer.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/of_gpio.h>
> +
> +
> +#define AS3935_AFE_GAIN		0x00
> +#define AS3935_AFE_MASK		0x3F
> +#define AS3935_AFE_GAIN_MAX	0x1F
> +
> +#define AS3935_INT		0x03
> +#define AS3935_INT_MASK		0x07
> +#define AS3935_DATA		0x07
> +#define AS3935_DATA_MASK	0x1F
> +
> +#define AS3935_TUNE_CAP		0x08
> +#define AS3935_CALIBRATE	0x3D
> +
> +#define AS3935_WRITE_DATA	(0x1 << 15)
> +#define AS3935_READ_DATA	(0x1 << 14)
> +#define AS3935_ADDRESS(x)	(x << 8)
> +
> +#define AS3935_EVENT_INT	(1<<3)
> +#define AS3935_NOISE_INT	(1<<0)
> +
> +struct as3935_state {
> +	struct spi_device *spi;
> +	struct mutex lock;
> +
> +	struct iio_trigger *trig;
> +	struct delayed_work work;
> +
> +	u8 tune_cap;
> +};
> +
> +static const struct iio_chan_spec as3935_channels[] = {
> +	{
> +		.type           = IIO_DISTANCE,
> +		.channel        = 0,
> +		.info_mask_separate =
> +			BIT(IIO_CHAN_INFO_RAW),
> +		.scan_index     = 0,
> +		.scan_type = {
> +			.sign           = 'u',
> +			.realbits       = 6,
> +			.storagebits    = 6,
> +		},
> +		.modified = 0,

channel and modified are not needed
storagebits should be a multiple of 8

> +	},
> +	IIO_CHAN_SOFT_TIMESTAMP(1),
> +};
> +
> +static const unsigned long as3935_available_scan_masks[] = { 0x01, 0x0 };

is this needed? there is just one channel

> +
> +static int as3935_read(struct as3935_state *st, unsigned int reg, int *val)
> +{
> +	u8 tx, rx;
> +	int ret;
> +
> +	struct spi_transfer xfers[] = {
> +		{
> +			.tx_buf = &tx,
> +			.bits_per_word = 8,
> +			.len = 1,
> +		}, {
> +			.rx_buf = &rx,
> +			.bits_per_word = 8,
> +			.len = 1,
> +		},
> +	};
> +
> +	mutex_lock(&st->lock);
> +	tx = (AS3935_READ_DATA | AS3935_ADDRESS(reg)) >> 8;
> +
> +	ret = spi_sync_transfer(st->spi, xfers, ARRAY_SIZE(xfers));
> +	mutex_unlock(&st->lock);
> +
> +	*val = rx;
> +
> +	return ret;
> +};
> +
> +static int as3935_write(struct as3935_state *st,
> +				unsigned int reg,
> +				unsigned int val)
> +{
> +	u8 buf[2];
> +	int ret;
> +
> +	mutex_lock(&st->lock);
> +	buf[0] = AS3935_WRITE_DATA | AS3935_ADDRESS(reg) >> 8;
> +	buf[1] = val;
> +
> +	ret = spi_write(st->spi, (u8 *) &buf, 2);
> +	mutex_unlock(&st->lock);
> +
> +	return ret;
> +};
> +
> +static ssize_t gain_boost_show(struct device *dev,

not prefixed with as3935_

> +				struct device_attribute *attr,
> +				char *buf)
> +{
> +	struct as3935_state *st = iio_priv(dev_to_iio_dev(dev));
> +	int val, ret;
> +
> +	ret = as3935_read(st, AS3935_AFE_GAIN, &val);
> +	if (ret)
> +		return ret;
> +	val = (val & AS3935_AFE_MASK) >> 1;
> +
> +	return sprintf(buf, "%d\n", val);
> +};
> +
> +static ssize_t gain_boost_store(struct device *dev,
> +					struct device_attribute *attr,
> +					const char *buf, size_t len)
> +{
> +	struct as3935_state *st = iio_priv(dev_to_iio_dev(dev));
> +	unsigned long val;
> +	int ret;
> +
> +	ret = kstrtoul((const char *) buf, 10, &val);
> +	if (ret)
> +		return -EINVAL;
> +
> +	if (val > AS3935_AFE_GAIN_MAX)
> +		return -EINVAL;
> +
> +	as3935_write(st, AS3935_AFE_GAIN, val << 1);
> +
> +	return len;
> +};
> +
> +static IIO_DEVICE_ATTR(gain_boost, S_IRUGO | S_IWUSR,
> +	gain_boost_show, gain_boost_store, 0);
> +
> +
> +static struct attribute *as3935_attributes[] = {
> +	&iio_dev_attr_gain_boost.dev_attr.attr,
> +	NULL,
> +};
> +
> +static struct attribute_group as3935_attribute_group = {
> +	.attrs = as3935_attributes,
> +};
> +
> +static int as3935_read_raw(struct iio_dev *indio_dev,
> +			   struct iio_chan_spec const *chan,
> +			   int *val,
> +			   int *val2,
> +			   long m)
> +{
> +	struct as3935_state *st = iio_priv(indio_dev);
> +
> +	if (m == IIO_CHAN_INFO_RAW) {
> +		int ret;
> +		*val = 0;
> +		ret = as3935_read(st, AS3935_DATA, val2);

huh, this always returns 0?
only val is return if IIO_VAL_INT

> +		if (ret)
> +			return ret;
> +		return IIO_VAL_INT;
> +	}
> +
> +	return -EINVAL;
> +}
> +
> +static const struct iio_info as3935_info = {
> +	.driver_module = THIS_MODULE,
> +	.attrs = &as3935_attribute_group,
> +	.read_raw = &as3935_read_raw,
> +};
> +
> +static const struct iio_buffer_setup_ops iio_triggered_buffer_setup_ops = {
> +	.postenable = &iio_triggered_buffer_postenable,
> +	.predisable = &iio_triggered_buffer_predisable,
> +};
> +
> +static irqreturn_t as3935_trigger_handler(int irq, void *private)
> +{
> +	struct iio_poll_func *pf = private;
> +	struct iio_dev *indio_dev = pf->indio_dev;
> +	struct as3935_state *st = iio_priv(indio_dev);
> +	int val, ret;
> +
> +	ret = as3935_read(st, AS3935_DATA, &val);
> +	if (ret)
> +		goto err_read;
> +	val &= AS3935_DATA_MASK;
> +	iio_push_to_buffers_with_timestamp(indio_dev, &val, iio_get_time_ns());
> +
> +	iio_trigger_notify_done(indio_dev->trig);

iio_trigger_notify_done() must always be called, most past err_read

> +err_read:
> +
> +	return IRQ_HANDLED;
> +};
> +
> +static const struct iio_trigger_ops iio_interrupt_trigger_ops = {
> +	.owner = THIS_MODULE,
> +};
> +
> +static void as3935_event_work(struct work_struct *work)
> +{
> +	struct as3935_state *st;
> +	struct spi_device *spi;
> +	int val;
> +
> +	st = container_of(work, struct as3935_state, work.work);
> +	spi = st->spi;
> +
> +	as3935_read(st, AS3935_INT, &val);
> +	val &= AS3935_INT_MASK;
> +
> +	switch (val) {
> +	case AS3935_EVENT_INT:
> +		iio_trigger_poll(st->trig, 0);
> +		break;
> +	case AS3935_NOISE_INT:
> +		dev_warn(&spi->dev, "noise level is too high");
> +		break;
> +	}
> +};
> +
> +static irqreturn_t as3935_interrupt_handler(int irq, void *private)
> +{
> +	struct iio_dev *indio_dev = private;
> +	struct as3935_state *st = iio_priv(indio_dev);
> +
> +	cancel_delayed_work(&st->work);
> +	schedule_delayed_work(&st->work, jiffies_to_msecs(3));
> +	return IRQ_HANDLED;
> +}
> +
> +static void calibrate_as3935(struct as3935_state *st)
> +{
> +	/* mask disturber interrupt bit */
> +	as3935_write(st, AS3935_INT, 1 << 5);
> +
> +	as3935_write(st, AS3935_CALIBRATE, 0x96);
> +	as3935_write(st, AS3935_TUNE_CAP, 1 << 5 | st->tune_cap);
> +
> +	mdelay(2);
> +	as3935_write(st, AS3935_TUNE_CAP, st->tune_cap);
> +}
> +
> +#ifdef CONFIG_PM_SLEEP
> +static int as3935_suspend(struct spi_device *spi, pm_message_t msg)
> +{
> +	struct iio_dev *indio_dev = spi_get_drvdata(spi);
> +	struct as3935_state *st = iio_priv(indio_dev);
> +	int val, ret;
> +
> +	ret = as3935_read(st, AS3935_AFE_GAIN, &val);
> +	if (ret)
> +		return ret;
> +	val |= 0x01;
> +
> +	return as3935_write(st, AS3935_AFE_GAIN, val);
> +}
> +
> +static int as3935_resume(struct spi_device *spi)
> +{
> +	struct iio_dev *indio_dev = spi_get_drvdata(spi);
> +	struct as3935_state *st = iio_priv(indio_dev);
> +	int val, ret;
> +
> +	ret = as3935_read(st, AS3935_AFE_GAIN, &val);
> +	if (ret)
> +		return ret;
> +	val &= ~1;
> +
> +	return as3935_write(st, AS3935_AFE_GAIN, val);
> +}
> +#else
> +#define as3935_suspend	NULL
> +#define as3935_resume	NULL
> +#endif
> +
> +static int as3935_probe(struct spi_device *spi)
> +{
> +	struct iio_dev *indio_dev;
> +	struct iio_trigger *trig;
> +	struct as3935_state *st;
> +	struct device_node *np = spi->dev.of_node;
> +	int gpio;
> +	int irq;
> +	int ret;
> +
> +	/* Grab the GPIO to use for lightning event interrupt */
> +	if (np)
> +		gpio = of_get_gpio(spi->dev.of_node, 0);
> +	else {
> +		dev_err(&spi->dev, "unable to get interrupt gpio\n");
> +		return -EINVAL;
> +	}
> +
> +	/* GPIO event setup */
> +	ret = devm_gpio_request(&spi->dev, gpio, "as3935");
> +	if (ret) {
> +		dev_err(&spi->dev, "failed to request GPIO %u\n", gpio);
> +		return ret;
> +	}
> +
> +	ret = gpio_direction_input(gpio);
> +	if (ret) {
> +		dev_err(&spi->dev, "failed to set pin direction\n");
> +		return -EINVAL;
> +	}
> +
> +	/* IRQ setup */
> +	irq = gpio_to_irq(gpio);
> +	if (irq < 0) {
> +		dev_err(&spi->dev, "failed to map GPIO to IRQ: %d\n", irq);
> +		return -EINVAL;
> +	}
> +
> +	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(st));
> +	if (!indio_dev)
> +		return -ENOMEM;
> +
> +	st = iio_priv(indio_dev);
> +	st->spi = spi;
> +	st->tune_cap = 0;
> +	spi_set_drvdata(spi, indio_dev);
> +	mutex_init(&st->lock);
> +	INIT_DELAYED_WORK(&st->work, as3935_event_work);
> +
> +	of_property_read_u8(np, "ams,tune-cap", &st->tune_cap);
> +	if (st->tune_cap > 15) {
> +		dev_err(&spi->dev,
> +			"wrong tune_cap setting of %d\n", st->tune_cap);
> +		return -EINVAL;
> +	}
> +
> +	indio_dev->dev.parent = &spi->dev;
> +	indio_dev->name = spi_get_device_id(spi)->name;
> +	indio_dev->channels = as3935_channels;
> +	indio_dev->num_channels = ARRAY_SIZE(as3935_channels);
> +	indio_dev->modes = INDIO_DIRECT_MODE;
> +	indio_dev->available_scan_masks = as3935_available_scan_masks;
> +	indio_dev->info = &as3935_info;
> +
> +	trig = devm_iio_trigger_alloc(&spi->dev, "%s-dev%d",
> +				      indio_dev->name, indio_dev->id);
> +
> +	if (!trig)
> +		return -ENOMEM;
> +
> +	st->trig = trig;
> +	trig->dev.parent = indio_dev->dev.parent;
> +	iio_trigger_set_drvdata(trig, indio_dev);
> +	trig->ops = &iio_interrupt_trigger_ops;
> +
> +	ret = iio_trigger_register(trig);
> +	if (ret) {
> +		dev_err(&spi->dev, "failed to register trigger\n");
> +		return ret;
> +	}
> +
> +	ret = iio_triggered_buffer_setup(indio_dev, NULL,
> +					&as3935_trigger_handler,
> +					&iio_triggered_buffer_setup_ops);
> +
> +	if (ret) {
> +		dev_err(&spi->dev, "cannot setup iio trigger\n");
> +		return -EINVAL;
> +	}
> +
> +	calibrate_as3935(st);
> +
> +	ret = devm_request_irq(&spi->dev, irq,
> +				&as3935_interrupt_handler,
> +				IRQF_TRIGGER_RISING,
> +				dev_name(&spi->dev),
> +				indio_dev);
> +
> +	if (ret) {
> +		dev_err(&spi->dev, "unable to request irq\n");
> +		goto uninit_buffer;
> +	}
> +
> +	ret = iio_device_register(indio_dev);
> +	if (ret < 0) {
> +		dev_err(&spi->dev, "unable to register device\n");
> +		goto uninit_buffer;
> +	}
> +
> +	return 0;
> +
> +uninit_buffer:
> +	iio_triggered_buffer_cleanup(indio_dev);

iio_trigger_unregister()?

> +
> +	return ret;
> +};
> +
> +static int as3935_remove(struct spi_device *spi)
> +{
> +	struct iio_dev *indio_dev = spi_get_drvdata(spi);
> +

iio_trigger_unregister()?
iio_triggered_buffer_cleanup()?

> +	iio_device_unregister(indio_dev);
> +	return 0;
> +};
> +
> +static const struct spi_device_id as3935_id[] = {
> +	{"as3935", 0},
> +	{},
> +};
> +MODULE_DEVICE_TABLE(spi, as3935_id);
> +
> +static struct spi_driver as3935_driver = {
> +	.driver = {
> +		.name	= "as3935",
> +		.owner	= THIS_MODULE,
> +	},
> +	.probe		= as3935_probe,
> +	.remove		= as3935_remove,
> +	.id_table	= as3935_id,
> +	.suspend	= as3935_suspend,
> +	.resume		= as3935_resume,
> +};
> +module_spi_driver(as3935_driver);
> +
> +MODULE_AUTHOR("Matt Ranostay <mranostay@gmail.com>");
> +MODULE_DESCRIPTION("AS3935 lightning sensor");
> +MODULE_LICENSE("GPL");
> 

-- 

Peter Meerwald
+43-664-2444418 (mobile)

Re: [PATCH 2/2] iio: Add AS3935 lightning sensor support

[Jonathan Cameron]

On January 30, 2014 10:37:19 AM GMT+00:00, Peter Meerwald <pmeerw@pmeerw.net> wrote:
>
>> AS3935 chipset can detect lightning strikes and reports those
>> back as events and the esimated distance to the storm.
>
>pretty cool :)
Indeed!
>
>the distance thing should be documented in 
>Documentation/ABI/testing/sysfs-bus-iio -- which unit (meters?) for 
>example
>
>sysfs attributes such as boost should be documented as well; or better
>use 
>a writable scale attribute if possible
>
>nitpicking inline

Couple of quick comments for now.

The driver should not be doing the gpio irq setup. There is no reason it needs to be a gpio that I can see. DT should hence also have interrupt not gpio.

Why all the pinctrl headers.

Curious question... What controls max spi fre
q? I would have thought that was fixed for the part hence not needed in device tree?

Do make sure to add sysfs attr docs as Peter suggested.
>
>> ---
>>  .../devicetree/bindings/iio/distance/as3935.txt    |  25 ++
>>  drivers/iio/Kconfig                                |   1 +
>>  drivers/iio/Makefile                               |   1 +
>>  drivers/iio/distance/Kconfig                       |  19 +
>>  drivers/iio/distance/Makefile                      |   6 +
>>  drivers/iio/distance/as3935.c                      | 459
>+++++++++++++++++++++
>>  6 files changed, 511 insertions(+)
>>  create mode 100644
>Documentation/devicetree/bindings/iio/distance/as3935.txt
>>  create mode 100644 drivers/iio/distance/Kconfig
>>  create mode 100644 drivers/iio/distance/Makefile
>>  create mode 100644 drivers/iio/distance/as3935.c
>> 
>> diff --git
>a/Documentation/devicetree/bindings/iio/distance/as3935.txt
>b/Documentation/devicetree/bindings/iio/distance/as3935.txt
>> new file mode 100644
>> index 0000000..af35827
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/iio/distance/as3935.txt
>> @@ -0,0 +1,25 @@
>> +Austrian Microsystems AS3935 Franklin lightning sensor device driver
>> +
>> +Required properties:
>> +	- compatible: must be "ams,as3935"
>> +	- reg: SPI chip select number for the device
>> +	- spi-max-frequency: Max SPI frequency to use
>> +	- spi-cpha: SPI Mode 1
>> +	- gpios: GPIO input of interrupt line from IRQ pin of AS3935 IC
>> +
>> +Optional properties:
>> +	- ams,tune-cap: Calibration tuning capacitor stepping value 0 - 15.
>> +	  Range of 0 to 120 pF, 8pF steps. This will require using the
>calibration
>> +	  data from the manufacturer.
>> +
>> +
>> +Example:
>> +
>> +		as3935@0 {
>> +			compatible = "ams,as3935";
>> +			reg = <0>;
>> +			spi-max-frequency = <100000>;
>> +			spi-cpha;
>> +			ams,tune-cap = /bits/ 8 <10>;
>> +			gpios = <&gpio1 16 10>;
>> +		};
>> diff --git a/drivers/iio/Kconfig b/drivers/iio/Kconfig
>> index 5dd0e12..5164a68 100644
>> --- a/drivers/iio/Kconfig
>> +++ b/drivers/iio/Kconfig
>> @@ -63,6 +63,7 @@ source "drivers/iio/adc/Kconfig"
>>  source "drivers/iio/amplifiers/Kconfig"
>>  source "drivers/iio/common/Kconfig"
>>  source "drivers/iio/dac/Kconfig"
>> +source "drivers/iio/distance/Kconfig"
>>  source "drivers/iio/frequency/Kconfig"
>>  source "drivers/iio/gyro/Kconfig"
>>  source "drivers/iio/humidity/Kconfig"
>> diff --git a/drivers/iio/Makefile b/drivers/iio/Makefile
>> index 887d390..1574731 100644
>> --- a/drivers/iio/Makefile
>> +++ b/drivers/iio/Makefile
>> @@ -16,6 +16,7 @@ obj-y += adc/
>>  obj-y += amplifiers/
>>  obj-y += common/
>>  obj-y += dac/
>> +obj-y += distance/
>>  obj-y += gyro/
>>  obj-y += frequency/
>>  obj-y += humidity/
>> diff --git a/drivers/iio/distance/Kconfig
>b/drivers/iio/distance/Kconfig
>> new file mode 100644
>> index 0000000..753352c
>> --- /dev/null
>> +++ b/drivers/iio/distance/Kconfig
>> @@ -0,0 +1,19 @@
>> +#
>> +# Distance sensors
>> +#
>> +
>> +menu "Lightning sensors"
>> +
>> +config AS3935
>> +	tristate "AS3935 Franklin lightning sensor"
>> +	select IIO_BUFFER
>> +	select IIO_TRIGGERED_BUFFER
>> +	depends on SPI
>> +	help
>> +	 If you say yes here you get support for the Austrian Microsystems
>> +	 AS3935 lightning detection sensor.
>> +
>> +	 This driver can also be built as a module. If so, the module
>> +	 will be called as3935
>> +
>> +endmenu
>> diff --git a/drivers/iio/distance/Makefile
>b/drivers/iio/distance/Makefile
>> new file mode 100644
>> index 0000000..f63b70d
>> --- /dev/null
>> +++ b/drivers/iio/distance/Makefile
>> @@ -0,0 +1,6 @@
>> +#
>> +# Makefile for IIO distance sensors
>> +#
>> +
>> +# When adding new entries keep the list in alphabetical order
>> +obj-$(CONFIG_AS3935)		+= as3935.o
>> diff --git a/drivers/iio/distance/as3935.c
>b/drivers/iio/distance/as3935.c
>> new file mode 100644
>> index 0000000..1a8f48d
>> --- /dev/null
>> +++ b/drivers/iio/distance/as3935.c
>> @@ -0,0 +1,459 @@
>> +/*
>> + * as3935.c - Support for AS3935 Franklin lightning sensor
>> + *
>> + * Copyright (C) 2014 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/workqueue.h>
>> +#include <linux/err.h>
>> +#include <linux/irq.h>
>> +#include <linux/gpio.h>
>> +#include <linux/spi/spi.h>
>> +#include <linux/iio/iio.h>
>> +#include <linux/iio/sysfs.h>
>> +#include <linux/iio/trigger.h>
>> +#include <linux/iio/trigger_consumer.h>
>> +#include <linux/iio/buffer.h>
>> +#include <linux/iio/triggered_buffer.h>
>> +#include <linux/pinctrl/pinctrl.h>
>> +#include <linux/pinctrl/pinmux.h>
>> +#include <linux/pinctrl/consumer.h>
>> +#include <linux/pm_runtime.h>
>> +#include <linux/of_gpio.h>
>> +
>> +
>> +#define AS3935_AFE_GAIN		0x00
>> +#define AS3935_AFE_MASK		0x3F
>> +#define AS3935_AFE_GAIN_MAX	0x1F
>> +
>> +#define AS3935_INT		0x03
>> +#define AS3935_INT_MASK		0x07
>> +#define AS3935_DATA		0x07
>> +#define AS3935_DATA_MASK	0x1F
>> +
>> +#define AS3935_TUNE_CAP		0x08
>> +#define AS3935_CALIBRATE	0x3D
>> +
>> +#define AS3935_WRITE_DATA	(0x1 << 15)
>> +#define AS3935_READ_DATA	(0x1 << 14)
>> +#define AS3935_ADDRESS(x)	(x << 8)
>> +
>> +#define AS3935_EVENT_INT	(1<<3)
>> +#define AS3935_NOISE_INT	(1<<0)
>> +
>> +struct as3935_state {
>> +	struct spi_device *spi;
>> +	struct mutex lock;
>> +
>> +	struct iio_trigger *trig;
>> +	struct delayed_work work;
>> +
>> +	u8 tune_cap;
>> +};
>> +
>> +static const struct iio_chan_spec as3935_channels[] = {
>> +	{
>> +		.type           = IIO_DISTANCE,
>> +		.channel        = 0,
>> +		.info_mask_separate =
>> +			BIT(IIO_CHAN_INFO_RAW),
>> +		.scan_index     = 0,
>> +		.scan_type = {
>> +			.sign           = 'u',
>> +			.realbits       = 6,
>> +			.storagebits    = 6,
>> +		},
>> +		.modified = 0,
>
>channel and modified are not needed
>storagebits should be a multiple of 8
>
>> +	},
>> +	IIO_CHAN_SOFT_TIMESTAMP(1),
>> +};
>> +
>> +static const unsigned long as3935_available_scan_masks[] = { 0x01,
>0x0 };
>
>is this needed? there is just one channel
>
>> +
>> +static int as3935_read(struct as3935_state *st, unsigned int reg,
>int *val)
>> +{
>> +	u8 tx, rx;
>> +	int ret;
>> +
>> +	struct spi_transfer xfers[] = {
>> +		{
>> +			.tx_buf = &tx,
>> +			.bits_per_word = 8,
>> +			.len = 1,
>> +		}, {
>> +			.rx_buf = &rx,
>> +			.bits_per_word = 8,
>> +			.len = 1,
>> +		},
>> +	};
>> +
>> +	mutex_lock(&st->lock);
>> +	tx = (AS3935_READ_DATA | AS3935_ADDRESS(reg)) >> 8;
>> +
>> +	ret = spi_sync_transfer(st->spi, xfers, ARRAY_SIZE(xfers));
>> +	mutex_unlock(&st->lock);
>> +
>> +	*val = rx;
>> +
>> +	return ret;
>> +};
>> +
>> +static int as3935_write(struct as3935_state *st,
>> +				unsigned int reg,
>> +				unsigned int val)
>> +{
>> +	u8 buf[2];
>> +	int ret;
>> +
>> +	mutex_lock(&st->lock);
>> +	buf[0] = AS3935_WRITE_DATA | AS3935_ADDRESS(reg) >> 8;
>> +	buf[1] = val;
>> +
>> +	ret = spi_write(st->spi, (u8 *) &buf, 2);
>> +	mutex_unlock(&st->lock);
>> +
>> +	return ret;
>> +};
>> +
>> +static ssize_t gain_boost_show(struct device *dev,
>
>not prefixed with as3935_
>
>> +				struct device_attribute *attr,
>> +				char *buf)
>> +{
>> +	struct as3935_state *st = iio_priv(dev_to_iio_dev(dev));
>> +	int val, ret;
>> +
>> +	ret = as3935_read(st, AS3935_AFE_GAIN, &val);
>> +	if (ret)
>> +		return ret;
>> +	val = (val & AS3935_AFE_MASK) >> 1;
>> +
>> +	return sprintf(buf, "%d\n", val);
>> +};
>> +
>> +static ssize_t gain_boost_store(struct device *dev,
>> +					struct device_attribute *attr,
>> +					const char *buf, size_t len)
>> +{
>> +	struct as3935_state *st = iio_priv(dev_to_iio_dev(dev));
>> +	unsigned long val;
>> +	int ret;
>> +
>> +	ret = kstrtoul((const char *) buf, 10, &val);
>> +	if (ret)
>> +		return -EINVAL;
>> +
>> +	if (val > AS3935_AFE_GAIN_MAX)
>> +		return -EINVAL;
>> +
>> +	as3935_write(st, AS3935_AFE_GAIN, val << 1);
>> +
>> +	return len;
>> +};
>> +
>> +static IIO_DEVICE_ATTR(gain_boost, S_IRUGO | S_IWUSR,
>> +	gain_boost_show, gain_boost_store, 0);
>> +
>> +
>> +static struct attribute *as3935_attributes[] = {
>> +	&iio_dev_attr_gain_boost.dev_attr.attr,
>> +	NULL,
>> +};
>> +
>> +static struct attribute_group as3935_attribute_group = {
>> +	.attrs = as3935_attributes,
>> +};
>> +
>> +static int as3935_read_raw(struct iio_dev *indio_dev,
>> +			   struct iio_chan_spec const *chan,
>> +			   int *val,
>> +			   int *val2,
>> +			   long m)
>> +{
>> +	struct as3935_state *st = iio_priv(indio_dev);
>> +
>> +	if (m == IIO_CHAN_INFO_RAW) {
>> +		int ret;
>> +		*val = 0;
>> +		ret = as3935_read(st, AS3935_DATA, val2);
>
>huh, this always returns 0?
>only val is return if IIO_VAL_INT
>
>> +		if (ret)
>> +			return ret;
>> +		return IIO_VAL_INT;
>> +	}
>> +
>> +	return -EINVAL;
>> +}
>> +
>> +static const struct iio_info as3935_info = {
>> +	.driver_module = THIS_MODULE,
>> +	.attrs = &as3935_attribute_group,
>> +	.read_raw = &as3935_read_raw,
>> +};
>> +
>> +static const struct iio_buffer_setup_ops
>iio_triggered_buffer_setup_ops = {
>> +	.postenable = &iio_triggered_buffer_postenable,
>> +	.predisable = &iio_triggered_buffer_predisable,
>> +};
>> +
>> +static irqreturn_t as3935_trigger_handler(int irq, void *private)
>> +{
>> +	struct iio_poll_func *pf = private;
>> +	struct iio_dev *indio_dev = pf->indio_dev;
>> +	struct as3935_state *st = iio_priv(indio_dev);
>> +	int val, ret;
>> +
>> +	ret = as3935_read(st, AS3935_DATA, &val);
>> +	if (ret)
>> +		goto err_read;
>> +	val &= AS3935_DATA_MASK;
>> +	iio_push_to_buffers_with_timestamp(indio_dev, &val,
>iio_get_time_ns());
>> +
>> +	iio_trigger_notify_done(indio_dev->trig);
>
>iio_trigger_notify_done() must always be called, most past err_read
>
>> +err_read:
>> +
>> +	return IRQ_HANDLED;
>> +};
>> +
>> +static const struct iio_trigger_ops iio_interrupt_trigger_ops = {
>> +	.owner = THIS_MODULE,
>> +};
>> +
>> +static void as3935_event_work(struct work_struct *work)
>> +{
>> +	struct as3935_state *st;
>> +	struct spi_device *spi;
>> +	int val;
>> +
>> +	st = container_of(work, struct as3935_state, work.work);
>> +	spi = st->spi;
>> +
>> +	as3935_read(st, AS3935_INT, &val);
>> +	val &= AS3935_INT_MASK;
>> +
>> +	switch (val) {
>> +	case AS3935_EVENT_INT:
>> +		iio_trigger_poll(st->trig, 0);
>> +		break;
>> +	case AS3935_NOISE_INT:
>> +		dev_warn(&spi->dev, "noise level is too high");
>> +		break;
>> +	}
>> +};
>> +
>> +static irqreturn_t as3935_interrupt_handler(int irq, void *private)
>> +{
>> +	struct iio_dev *indio_dev = private;
>> +	struct as3935_state *st = iio_priv(indio_dev);
>> +
>> +	cancel_delayed_work(&st->work);
>> +	schedule_delayed_work(&st->work, jiffies_to_msecs(3));
>> +	return IRQ_HANDLED;
>> +}
>> +
>> +static void calibrate_as3935(struct as3935_state *st)
>> +{
>> +	/* mask disturber interrupt bit */
>> +	as3935_write(st, AS3935_INT, 1 << 5);
>> +
>> +	as3935_write(st, AS3935_CALIBRATE, 0x96);
>> +	as3935_write(st, AS3935_TUNE_CAP, 1 << 5 | st->tune_cap);
>> +
>> +	mdelay(2);
>> +	as3935_write(st, AS3935_TUNE_CAP, st->tune_cap);
>> +}
>> +
>> +#ifdef CONFIG_PM_SLEEP
>> +static int as3935_suspend(struct spi_device *spi, pm_message_t msg)
>> +{
>> +	struct iio_dev *indio_dev = spi_get_drvdata(spi);
>> +	struct as3935_state *st = iio_priv(indio_dev);
>> +	int val, ret;
>> +
>> +	ret = as3935_read(st, AS3935_AFE_GAIN, &val);
>> +	if (ret)
>> +		return ret;
>> +	val |= 0x01;
>> +
>> +	return as3935_write(st, AS3935_AFE_GAIN, val);
>> +}
>> +
>> +static int as3935_resume(struct spi_device *spi)
>> +{
>> +	struct iio_dev *indio_dev = spi_get_drvdata(spi);
>> +	struct as3935_state *st = iio_priv(indio_dev);
>> +	int val, ret;
>> +
>> +	ret = as3935_read(st, AS3935_AFE_GAIN, &val);
>> +	if (ret)
>> +		return ret;
>> +	val &= ~1;
>> +
>> +	return as3935_write(st, AS3935_AFE_GAIN, val);
>> +}
>> +#else
>> +#define as3935_suspend	NULL
>> +#define as3935_resume	NULL
>> +#endif
>> +
>> +static int as3935_probe(struct spi_device *spi)
>> +{
>> +	struct iio_dev *indio_dev;
>> +	struct iio_trigger *trig;
>> +	struct as3935_state *st;
>> +	struct device_node *np = spi->dev.of_node;
>> +	int gpio;
>> +	int irq;
>> +	int ret;
>> +
>> +	/* Grab the GPIO to use for lightning event interrupt */
>> +	if (np)
>> +		gpio = of_get_gpio(spi->dev.of_node, 0);
>> +	else {
>> +		dev_err(&spi->dev, "unable to get interrupt gpio\n");
>> +		return -EINVAL;
>> +	}
>> +
>> +	/* GPIO event setup */
>> +	ret = devm_gpio_request(&spi->dev, gpio, "as3935");
>> +	if (ret) {
>> +		dev_err(&spi->dev, "failed to request GPIO %u\n", gpio);
>> +		return ret;
>> +	}
>> +
>> +	ret = gpio_direction_input(gpio);
>> +	if (ret) {
>> +		dev_err(&spi->dev, "failed to set pin direction\n");
>> +		return -EINVAL;
>> +	}
>> +
>> +	/* IRQ setup */
>> +	irq = gpio_to_irq(gpio);
>> +	if (irq < 0) {
>> +		dev_err(&spi->dev, "failed to map GPIO to IRQ: %d\n", irq);
>> +		return -EINVAL;
>> +	}
>> +
>> +	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(st));
>> +	if (!indio_dev)
>> +		return -ENOMEM;
>> +
>> +	st = iio_priv(indio_dev);
>> +	st->spi = spi;
>> +	st->tune_cap = 0;
>> +	spi_set_drvdata(spi, indio_dev);
>> +	mutex_init(&st->lock);
>> +	INIT_DELAYED_WORK(&st->work, as3935_event_work);
>> +
>> +	of_property_read_u8(np, "ams,tune-cap", &st->tune_cap);
>> +	if (st->tune_cap > 15) {
>> +		dev_err(&spi->dev,
>> +			"wrong tune_cap setting of %d\n", st->tune_cap);
>> +		return -EINVAL;
>> +	}
>> +
>> +	indio_dev->dev.parent = &spi->dev;
>> +	indio_dev->name = spi_get_device_id(spi)->name;
>> +	indio_dev->channels = as3935_channels;
>> +	indio_dev->num_channels = ARRAY_SIZE(as3935_channels);
>> +	indio_dev->modes = INDIO_DIRECT_MODE;
>> +	indio_dev->available_scan_masks = as3935_available_scan_masks;
>> +	indio_dev->info = &as3935_info;
>> +
>> +	trig = devm_iio_trigger_alloc(&spi->dev, "%s-dev%d",
>> +				      indio_dev->name, indio_dev->id);
>> +
>> +	if (!trig)
>> +		return -ENOMEM;
>> +
>> +	st->trig = trig;
>> +	trig->dev.parent = indio_dev->dev.parent;
>> +	iio_trigger_set_drvdata(trig, indio_dev);
>> +	trig->ops = &iio_interrupt_trigger_ops;
>> +
>> +	ret = iio_trigger_register(trig);
>> +	if (ret) {
>> +		dev_err(&spi->dev, "failed to register trigger\n");
>> +		return ret;
>> +	}
>> +
>> +	ret = iio_triggered_buffer_setup(indio_dev, NULL,
>> +					&as3935_trigger_handler,
>> +					&iio_triggered_buffer_setup_ops);
>> +
>> +	if (ret) {
>> +		dev_err(&spi->dev, "cannot setup iio trigger\n");
>> +		return -EINVAL;
>> +	}
>> +
>> +	calibrate_as3935(st);
>> +
>> +	ret = devm_request_irq(&spi->dev, irq,
>> +				&as3935_interrupt_handler,
>> +				IRQF_TRIGGER_RISING,
>> +				dev_name(&spi->dev),
>> +				indio_dev);
>> +
>> +	if (ret) {
>> +		dev_err(&spi->dev, "unable to request irq\n");
>> +		goto uninit_buffer;
>> +	}
>> +
>> +	ret = iio_device_register(indio_dev);
>> +	if (ret < 0) {
>> +		dev_err(&spi->dev, "unable to register device\n");
>> +		goto uninit_buffer;
>> +	}
>> +
>> +	return 0;
>> +
>> +uninit_buffer:
>> +	iio_triggered_buffer_cleanup(indio_dev);
>
>iio_trigger_unregister()?
>
>> +
>> +	return ret;
>> +};
>> +
>> +static int as3935_remove(struct spi_device *spi)
>> +{
>> +	struct iio_dev *indio_dev = spi_get_drvdata(spi);
>> +
>
>iio_trigger_unregister()?
>iio_triggered_buffer_cleanup()?
>
>> +	iio_device_unregister(indio_dev);
>> +	return 0;
>> +};
>> +
>> +static const struct spi_device_id as3935_id[] = {
>> +	{"as3935", 0},
>> +	{},
>> +};
>> +MODULE_DEVICE_TABLE(spi, as3935_id);
>> +
>> +static struct spi_driver as3935_driver = {
>> +	.driver = {
>> +		.name	= "as3935",
>> +		.owner	= THIS_MODULE,
>> +	},
>> +	.probe		= as3935_probe,
>> +	.remove		= as3935_remove,
>> +	.id_table	= as3935_id,
>> +	.suspend	= as3935_suspend,
>> +	.resume		= as3935_resume,
>> +};
>> +module_spi_driver(as3935_driver);
>> +
>> +MODULE_AUTHOR("Matt Ranostay <mranostay@gmail.com>");
>> +MODULE_DESCRIPTION("AS3935 lightning sensor");
>> +MODULE_LICENSE("GPL");
>> 

-- 
Sent from my Android phone with K-9 Mail. Please excuse my brevity.

Re: [PATCH 2/2] iio: Add AS3935 lightning sensor support

[Alexandre Belloni]

Hi Matt,

On 30/01/2014 at 02:11:13 -0800, Matt Ranostay wrote :
> AS3935 chipset can detect lightning strikes and reports those
> back as events and the esimated distance to the storm.
> 
> Signed-off-by: Matt Ranostay <mranostay@gmail.com>
> ---
>  .../devicetree/bindings/iio/distance/as3935.txt    |  25 ++

Maybe I'm wrong but wasn't the agreement that the bindings documentation
has to be sent separately to the devicetree mailing list ?

>  drivers/iio/Kconfig                                |   1 +
>  drivers/iio/Makefile                               |   1 +
>  drivers/iio/distance/Kconfig                       |  19 +
>  drivers/iio/distance/Makefile                      |   6 +
>  drivers/iio/distance/as3935.c                      | 459 +++++++++++++++++++++
>  6 files changed, 511 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/iio/distance/as3935.txt
>  create mode 100644 drivers/iio/distance/Kconfig
>  create mode 100644 drivers/iio/distance/Makefile
>  create mode 100644 drivers/iio/distance/as3935.c

-- 
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

Re: [PATCH 2/2] iio: Add AS3935 lightning sensor support

[Matt Porter]

On Fri, Jan 31, 2014 at 10:05:07PM +0100, Alexandre Belloni wrote:
> Hi Matt,
> 
> On 30/01/2014 at 02:11:13 -0800, Matt Ranostay wrote :
> > AS3935 chipset can detect lightning strikes and reports those
> > back as events and the esimated distance to the storm.
> > 
> > Signed-off-by: Matt Ranostay <mranostay@gmail.com>
> > ---
> >  .../devicetree/bindings/iio/distance/as3935.txt    |  25 ++
> 
> Maybe I'm wrong but wasn't the agreement that the bindings documentation
> has to be sent separately to the devicetree mailing list ?

That's correct. It needs to be separated for ease of review.

-anothermatt

Re: [PATCH 1/2] iio: add IIO_DISTANCE type

[Marek Vasut]

On Friday, January 31, 2014 at 04:38:22 PM, Matt Ranostay wrote:

The commit message is completely missing, it's entirely unclear what the 
intention of this patch is. Please write a commit message !

> Signed-off-by: Matt Ranostay <mranostay@gmail.com>
> ---
>  drivers/iio/industrialio-core.c | 1 +
>  include/linux/iio/types.h       | 1 +
>  2 files changed, 2 insertions(+)
> 
> diff --git a/drivers/iio/industrialio-core.c
> b/drivers/iio/industrialio-core.c index acc911a..ac999ab 100644
> --- a/drivers/iio/industrialio-core.c
> +++ b/drivers/iio/industrialio-core.c
> @@ -70,6 +70,7 @@ static const char * const iio_chan_type_name_spec[] = {
>  	[IIO_CCT] = "cct",
>  	[IIO_PRESSURE] = "pressure",
>  	[IIO_HUMIDITYRELATIVE] = "humidityrelative",
> +	[IIO_DISTANCE] = "distance",
>  };
> 
>  static const char * const iio_modifier_names[] = {
> diff --git a/include/linux/iio/types.h b/include/linux/iio/types.h
> index 084d882..675c2d8 100644
> --- a/include/linux/iio/types.h
> +++ b/include/linux/iio/types.h
> @@ -30,6 +30,7 @@ enum iio_chan_type {
>  	IIO_CCT,
>  	IIO_PRESSURE,
>  	IIO_HUMIDITYRELATIVE,
> +	IIO_DISTANCE,
>  };
> 
>  enum iio_modifier {

Best regards,
Marek Vasut

[PATCH 1/2] iio: add IIO_DISTANCE type

[Matt Ranostay]

Signed-off-by: Matt Ranostay <mranostay@gmail.com>
---
 drivers/iio/industrialio-core.c | 1 +
 include/linux/iio/types.h       | 1 +
 2 files changed, 2 insertions(+)

diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index acc911a..ac999ab 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -70,6 +70,7 @@ static const char * const iio_chan_type_name_spec[] = {
 	[IIO_CCT] = "cct",
 	[IIO_PRESSURE] = "pressure",
 	[IIO_HUMIDITYRELATIVE] = "humidityrelative",
+	[IIO_DISTANCE] = "distance",
 };
 
 static const char * const iio_modifier_names[] = {
diff --git a/include/linux/iio/types.h b/include/linux/iio/types.h
index 084d882..675c2d8 100644
--- a/include/linux/iio/types.h
+++ b/include/linux/iio/types.h
@@ -30,6 +30,7 @@ enum iio_chan_type {
 	IIO_CCT,
 	IIO_PRESSURE,
 	IIO_HUMIDITYRELATIVE,
+	IIO_DISTANCE,
 };
 
 enum iio_modifier {
-- 
1.8.3.2