On 12/02/14 04:31, Matt Ranostay wrote:
AS3935 chipset can detect lightning strikes and reports those back as
events and the estimated distance to the storm.
Signed-off-by: Matt Ranostay <redacted>
Given the resounding lack of support for my spherical coordinates
suggestion, assuming nothing changes, I'll take this as a proximity driver.
However, some outstanding bits and pieces and I'm not keen on a custom
driver attribute for the boost gain if we can manage something more general.
quoted hunk
---
.../ABI/testing/sysfs-bus-iio-proximity-as3935 | 18 +
drivers/iio/Kconfig | 1 +
drivers/iio/Makefile | 1 +
drivers/iio/proximity/Kconfig | 19 +
drivers/iio/proximity/Makefile | 6 +
drivers/iio/proximity/as3935.c | 446 +++++++++++++++++++++
6 files changed, 491 insertions(+)
create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-proximity-as3935
create mode 100644 drivers/iio/proximity/Kconfig
create mode 100644 drivers/iio/proximity/Makefile
create mode 100644 drivers/iio/proximity/as3935.c
diff --git a/Documentation/ABI/testing/sysfs-bus-iio-proximity-as3935 b/Documentation/ABI/testing/sysfs-bus-iio-proximity-as3935
new file mode 100644
index 0000000..fc92bce
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-iio-proximity-as3935
@@ -0,0 +1,18 @@
+What /sys/bus/iio/devices/iio:deviceX/in_proximity_raw
+Date: January 2014
+KernelVersion: 3.15
+Contact: Matt Ranostay <mranostay-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
+Description:
+ Get the current distance in meters of storm (1km steps)
+ 1000 = storm overhead
+ 1000-40000 = distance in meters
+ 63000 = out of range
If these are 'real' units then it should be in_proximity_input (IIO_INFO_PROCESSED). The overhead one is a litle interesting. I'd be tempted to just define
it as meters and neglect to mention that it is meaningless any nearer.
Also we proximity is a standard type so we the help should be in the main
file and not device specific. I wonder if for out of range it should return
an error as it means it really doesn't have any answer rather than anything
else...
quoted hunk
+
+What /sys/bus/iio/devices/iio:deviceX/gain_boost
+Date: January 2014
+KernelVersion: 3.15
+Contact: Matt Ranostay [off-list ref]
+Description:
+ Show or set the gain boost of the amp, from 0-31 range.
+ 18 = indoors (default)
+ 14 = outdoors
diff --git a/drivers/iio/Kconfig b/drivers/iio/Kconfig
index 5dd0e12..743485e 100644
--- a/drivers/iio/Kconfig
+++ b/drivers/iio/Kconfig
@@ -74,6 +74,7 @@ if IIO_TRIGGER
source "drivers/iio/trigger/Kconfig"
endif #IIO_TRIGGER
source "drivers/iio/pressure/Kconfig"
+source "drivers/iio/proximity/Kconfig"
source "drivers/iio/temperature/Kconfig"
endif # IIOdiff --git a/drivers/iio/Makefile b/drivers/iio/Makefile
index 887d390..698afc2 100644
--- a/drivers/iio/Makefile
+++ b/drivers/iio/Makefile
@@ -24,5 +24,6 @@ obj-y += light/
obj-y += magnetometer/
obj-y += orientation/
obj-y += pressure/
+obj-y += proximity/
obj-y += temperature/
obj-y += trigger/
diff --git a/drivers/iio/proximity/Kconfig b/drivers/iio/proximity/Kconfig
new file mode 100644
index 0000000..0c8cdf5
--- /dev/null
+++ b/drivers/iio/proximity/Kconfig
@@ -0,0 +1,19 @@
+#
+# Proximity sensors
+#
+
+menu "Lightning sensors"
+
+config AS3935
+ tristate "AS3935 Franklin lightning sensor"
+ select IIO_BUFFER
+ select IIO_TRIGGERED_BUFFER
+ depends on SPI
+ help
+ Say Y here to build SPI interface support for the Austrian
+ Microsystems AS3935 lightning detection sensor.
+
+ To compile this driver as a module, choose M here: the
+ module will be called as3935
+
+endmenu
diff --git a/drivers/iio/proximity/Makefile b/drivers/iio/proximity/Makefile
new file mode 100644
index 0000000..743adee
--- /dev/null
+++ b/drivers/iio/proximity/Makefile
@@ -0,0 +1,6 @@
+#
+# Makefile for IIO proximity sensors
+#
+
+# When adding new entries keep the list in alphabetical order
+obj-$(CONFIG_AS3935) += as3935.o
diff --git a/drivers/iio/proximity/as3935.c b/drivers/iio/proximity/as3935.c
new file mode 100644
index 0000000..75ef034
--- /dev/null
+++ b/drivers/iio/proximity/as3935.c
@@ -0,0 +1,446 @@
+/*
+ * as3935.c - Support for AS3935 Franklin lightning sensor
+ *
+ * Copyright (C) 2014 Matt Ranostay <mranostay-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
+ *
+ * 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 blank line here.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/workqueue.h>
+#include <linux/mutex.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/pm_runtime.h>
This isn't doing runtime pm so is this the right header?
+#include <linux/of_gpio.h>
+
+
+#define AS3935_AFE_GAIN 0x00
+#define AS3935_AFE_MASK 0x3F
+#define AS3935_AFE_GAIN_MAX 0x1F
+#define AS3935_AFE_PWR_BIT BIT(0)
+
+#define AS3935_INT 0x03
+#define AS3935_INT_MASK 0x07
+#define AS3935_EVENT_INT BIT(3)
+#define AS3935_NOISE_INT BIT(1)
+
+#define AS3935_DATA 0x07
+#define AS3935_DATA_MASK 0x3F
+
+#define AS3935_TUNE_CAP 0x08
+#define AS3935_CALIBRATE 0x3D
+
+#define AS3935_WRITE_DATA BIT(15)
+#define AS3935_READ_DATA BIT(14)
+#define AS3935_ADDRESS(x) ((x) << 8)
+
+#define MAX_PF_CAP 120
+#define TUNE_CAP_DIV 8
+
+struct as3935_state {
+ struct spi_device *spi;
+ struct iio_trigger *trig;
+ struct mutex lock;
+ struct delayed_work work;
+
The point of the ____cacheline_aligned is to ensure that when allocated
the buffer does not share a cacheline with anything else. It does this
by fixing teh starting location. Nothing is done about the end location.
Hence this *must* be the last element in the structure. Care is taken
in the iio_dev allocation to ensure that the start of the private structure
is appropriately aligned and there is nothing after it.
i.e. tune_cap must be above the next line.
+ u8 buf[2] ____cacheline_aligned;
+ u32 tune_cap;
+};
+
+static const struct iio_chan_spec as3935_channels[] = {
+ {
+ .type = IIO_PROXIMITY,
+ .info_mask_separate =
+ BIT(IIO_CHAN_INFO_RAW),
+ .scan_index = 0,
+ .scan_type = {
+ .sign = 'u',
+ .realbits = 6,
+ .storagebits = 8,
+ },
+ },
+ IIO_CHAN_SOFT_TIMESTAMP(1),
+};
+
+static int as3935_read(struct as3935_state *st, unsigned int reg, int *val)
+{
+ u8 cmd;
+ int ret;
+
+ cmd = (AS3935_READ_DATA | AS3935_ADDRESS(reg)) >> 8;
+ ret = spi_w8r8(st->spi, cmd);
+ if (ret < 0)
+ return ret;
+ *val = ret;
+
+ return 0;
+};
+
+static int as3935_write(struct as3935_state *st,
+ unsigned int reg,
+ unsigned int val)
+{
I wouldn't bother with the local pointer copy. Slightly
obscures what is giong on to save a few character.
+ u8 *buf = st->buf;
+
+ buf[0] = (AS3935_WRITE_DATA | AS3935_ADDRESS(reg)) >> 8;
+ buf[1] = val;
+
+ return spi_write(st->spi, (u8 *) buf, 2);
Why the typecast? It's already a u8 *
+};
+
+static ssize_t as3935_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 as3935_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,
+ as3935_gain_boost_show, as3935_gain_boost_store, 0);
+
+
+static struct attribute *as3935_attributes[] = {
+ &iio_dev_attr_gain_boost.dev_attr.attr,
So what is this really? Could it be considered a calibration scale?
Or a straight _scale? Is it effecting the measurement, or
the sensitivity to make a measurement? If the second then
we probably want a more general naming.
Perhaps
in_detectionsensitivy or similar (that's a quick random suggestion
- I'd prefer something better thought out ;)
+ 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);
+ int ret;
+
+ if (m != IIO_CHAN_INFO_RAW)
+ return -EINVAL;
+
+ *val2 = 0;
+ ret = as3935_read(st, AS3935_DATA, val);
+ if (ret)
+ return ret;
+ *val *= 1000;
+
+ return IIO_VAL_INT;
+}
+
+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,
+};
These are the defaults - don't provide any and you'll get the same thing
(see industrialio-triggered-buffer.c)
+
+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;
+ val *= 1000;
+
+ iio_push_to_buffers_with_timestamp(indio_dev, &val, pf->timestamp);
+err_read:
+ iio_trigger_notify_done(indio_dev->trig);
+
+ 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;
+ int val;
+
+ st = container_of(work, struct as3935_state, work.work);
+
+ as3935_read(st, AS3935_INT, &val);
+ val &= AS3935_INT_MASK;
+
+ switch (val) {
+ case AS3935_EVENT_INT:
+ iio_trigger_poll(st->trig, iio_get_time_ns());
+ break;
+ case AS3935_NOISE_INT:
This could be provided as an event perhaps? Not sure, but splurging in
the log is probably going to be missed.
+ dev_warn(&st->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);
+
/*
* Delay..
+ /* Delay work for >2 milliseconds after an interrupt to allow
+ * estimated distance to recalculated.
+ */
+
+ schedule_delayed_work(&st->work, msecs_to_jiffies(3));
+
+ return IRQ_HANDLED;
+}
+
+static void calibrate_as3935(struct as3935_state *st)
+{
+ mutex_lock(&st->lock);
+
+ /* mask disturber interrupt bit */
+ as3935_write(st, AS3935_INT, 1<<5);
+
+ as3935_write(st, AS3935_CALIBRATE, 0x96);
1 << 5 as it's a binary operator.
+ as3935_write(st, AS3935_TUNE_CAP, 1<<5 | (st->tune_cap / TUNE_CAP_DIV));
+
+ mdelay(2);
+ as3935_write(st, AS3935_TUNE_CAP, (st->tune_cap / TUNE_CAP_DIV));
+
+ mutex_unlock(&st->lock);
+}
+
+#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;
+
+ mutex_lock(&st->lock);
+ ret = as3935_read(st, AS3935_AFE_GAIN, &val);
+ if (ret)
+ goto err_suspend;
+ val |= AS3935_AFE_PWR_BIT;
+
+ ret = as3935_write(st, AS3935_AFE_GAIN, val);
+
+err_suspend:
+ mutex_unlock(&st->lock);
+
+ return ret;
+}
+
+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;
+
+ mutex_lock(&st->lock);
+ ret = as3935_read(st, AS3935_AFE_GAIN, &val);
+ if (ret)
+ goto err_resume;
+ val &= ~AS3935_AFE_PWR_BIT;
+ ret = as3935_write(st, AS3935_AFE_GAIN, val);
+
+err_resume:
+ mutex_unlock(&st->lock);
+
+ return ret;
+}
+#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 ret;
+
... is specified?
+ /* Be sure lightning event interrupt */
+ if (!spi->irq) {
+ dev_err(&spi->dev, "unable to get event interrupt\n");
+ 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);
+
+ ret = of_property_read_u32(np,
+ "ams,tuning-capacitor-pf", &st->tune_cap);
+ if (ret) {
+ st->tune_cap = 0;
+ dev_warn(&spi->dev,
+ "no tuning-capacitor-pf set, defaulting to %d",
+ st->tune_cap);
+ }
+
+ if (st->tune_cap > MAX_PF_CAP) {
+ dev_err(&spi->dev,
+ "wrong tuning-capacitor-pf 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->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");
This will unroll the triggered_buffer_setup that has errored out.
Hence you will unregister a buffer that was never registered.
This should have it's own label to goto that only unregisters the
trigger.
+ goto unregister_trigger;
+ }
+
+ calibrate_as3935(st);
+
+ ret = devm_request_irq(&spi->dev, spi->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 unregister_trigger;
+ }
+
+ ret = iio_device_register(indio_dev);
+ if (ret < 0) {
+ dev_err(&spi->dev, "unable to register device\n");
+ goto unregister_trigger;
+ }
+ return 0;
+
+unregister_trigger:
These should be in the opposite order to conform to standard
error unrolling (undo things in reverse order.
+ iio_trigger_unregister(st->trig);
+ 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);
+ struct as3935_state *st = iio_priv(indio_dev);
+
+ iio_device_unregister(indio_dev);
+ iio_triggered_buffer_cleanup(indio_dev);
+ iio_trigger_unregister(st->trig);
+
+ 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 [off-list ref]");
+MODULE_DESCRIPTION("AS3935 lightning sensor");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("spi:as3935");
On Thu, Mar 6, 2014 at 11:04 AM, Jonathan Cameron [off-list ref] wrote:
On 12/02/14 04:31, Matt Ranostay wrote:
quoted
AS3935 chipset can detect lightning strikes and reports those back as
events and the estimated distance to the storm.
Signed-off-by: Matt Ranostay <redacted>
Given the resounding lack of support for my spherical coordinates
suggestion, assuming nothing changes, I'll take this as a proximity driver.
However, some outstanding bits and pieces and I'm not keen on a custom
driver attribute for the boost gain if we can manage something more general.
Ok comments below :)
quoted
---
.../ABI/testing/sysfs-bus-iio-proximity-as3935 | 18 +
drivers/iio/Kconfig | 1 +
drivers/iio/Makefile | 1 +
drivers/iio/proximity/Kconfig | 19 +
drivers/iio/proximity/Makefile | 6 +
drivers/iio/proximity/as3935.c | 446
+++++++++++++++++++++
6 files changed, 491 insertions(+)
create mode 100644
Documentation/ABI/testing/sysfs-bus-iio-proximity-as3935
create mode 100644 drivers/iio/proximity/Kconfig
create mode 100644 drivers/iio/proximity/Makefile
create mode 100644 drivers/iio/proximity/as3935.c
diff --git a/Documentation/ABI/testing/sysfs-bus-iio-proximity-as3935
b/Documentation/ABI/testing/sysfs-bus-iio-proximity-as3935
new file mode 100644
index 0000000..fc92bce
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-iio-proximity-as3935
@@ -0,0 +1,18 @@
+What /sys/bus/iio/devices/iio:deviceX/in_proximity_raw
+Date: January 2014
+KernelVersion: 3.15
+Contact: Matt Ranostay <mranostay-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
+Description:
+ Get the current distance in meters of storm (1km steps)
+ 1000 = storm overhead
+ 1000-40000 = distance in meters
+ 63000 = out of range
If these are 'real' units then it should be in_proximity_input
(IIO_INFO_PROCESSED). The overhead one is a litle interesting. I'd be
tempted to just define
it as meters and neglect to mention that it is meaningless any nearer.
Also we proximity is a standard type so we the help should be in the main
file and not device specific. I wonder if for out of range it should return
an error as it means it really doesn't have any answer rather than anything
else...
Yeah the 63000 seems weird to me even. Would -EINVAL be a correct
error code to return for that state?
As for overhead the sensor can only do 1km intervals...
Would a better plan just to have...
Description:
Get the current distance in meters of storm (1km steps)
1000-40000 = distance in meters
quoted
+
+What /sys/bus/iio/devices/iio:deviceX/gain_boost
+Date: January 2014
+KernelVersion: 3.15
+Contact: Matt Ranostay [off-list ref]
+Description:
+ Show or set the gain boost of the amp, from 0-31 range.
+ 18 = indoors (default)
+ 14 = outdoors
diff --git a/drivers/iio/Kconfig b/drivers/iio/Kconfig
index 5dd0e12..743485e 100644
--- a/drivers/iio/Kconfig
+++ b/drivers/iio/Kconfig
@@ -74,6 +74,7 @@ if IIO_TRIGGER
source "drivers/iio/trigger/Kconfig"
endif #IIO_TRIGGER
source "drivers/iio/pressure/Kconfig"
+source "drivers/iio/proximity/Kconfig"
source "drivers/iio/temperature/Kconfig"
endif # IIOdiff --git a/drivers/iio/Makefile b/drivers/iio/Makefile
index 887d390..698afc2 100644
--- a/drivers/iio/Makefile
+++ b/drivers/iio/Makefile
@@ -24,5 +24,6 @@ obj-y += light/
obj-y += magnetometer/
obj-y += orientation/
obj-y += pressure/
+obj-y += proximity/
obj-y += temperature/
obj-y += trigger/
diff --git a/drivers/iio/proximity/Kconfig b/drivers/iio/proximity/Kconfig
new file mode 100644
index 0000000..0c8cdf5
--- /dev/null
+++ b/drivers/iio/proximity/Kconfig
@@ -0,0 +1,19 @@
+#
+# Proximity sensors
+#
+
+menu "Lightning sensors"
+
+config AS3935
+ tristate "AS3935 Franklin lightning sensor"
+ select IIO_BUFFER
+ select IIO_TRIGGERED_BUFFER
+ depends on SPI
+ help
+ Say Y here to build SPI interface support for the Austrian
+ Microsystems AS3935 lightning detection sensor.
+
+ To compile this driver as a module, choose M here: the
+ module will be called as3935
+
+endmenu
diff --git a/drivers/iio/proximity/Makefile
b/drivers/iio/proximity/Makefile
new file mode 100644
index 0000000..743adee
--- /dev/null
+++ b/drivers/iio/proximity/Makefile
@@ -0,0 +1,6 @@
+#
+# Makefile for IIO proximity sensors
+#
+
+# When adding new entries keep the list in alphabetical order
+obj-$(CONFIG_AS3935) += as3935.o
diff --git a/drivers/iio/proximity/as3935.c
b/drivers/iio/proximity/as3935.c
new file mode 100644
index 0000000..75ef034
--- /dev/null
+++ b/drivers/iio/proximity/as3935.c
@@ -0,0 +1,446 @@
+/*
+ * as3935.c - Support for AS3935 Franklin lightning sensor
+ *
+ * Copyright (C) 2014 Matt Ranostay <mranostay-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
+ *
+ * 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 blank line here.
quoted
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/workqueue.h>
+#include <linux/mutex.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/pm_runtime.h>
This isn't doing runtime pm so is this the right header?
quoted
+#include <linux/of_gpio.h>
+
+
+#define AS3935_AFE_GAIN 0x00
+#define AS3935_AFE_MASK 0x3F
+#define AS3935_AFE_GAIN_MAX 0x1F
+#define AS3935_AFE_PWR_BIT BIT(0)
+
+#define AS3935_INT 0x03
+#define AS3935_INT_MASK 0x07
+#define AS3935_EVENT_INT BIT(3)
+#define AS3935_NOISE_INT BIT(1)
+
+#define AS3935_DATA 0x07
+#define AS3935_DATA_MASK 0x3F
+
+#define AS3935_TUNE_CAP 0x08
+#define AS3935_CALIBRATE 0x3D
+
+#define AS3935_WRITE_DATA BIT(15)
+#define AS3935_READ_DATA BIT(14)
+#define AS3935_ADDRESS(x) ((x) << 8)
+
+#define MAX_PF_CAP 120
+#define TUNE_CAP_DIV 8
+
+struct as3935_state {
+ struct spi_device *spi;
+ struct iio_trigger *trig;
+ struct mutex lock;
+ struct delayed_work work;
+
The point of the ____cacheline_aligned is to ensure that when allocated
the buffer does not share a cacheline with anything else. It does this
by fixing teh starting location. Nothing is done about the end location.
Hence this *must* be the last element in the structure. Care is taken
in the iio_dev allocation to ensure that the start of the private structure
is appropriately aligned and there is nothing after it.
i.e. tune_cap must be above the next line.
Thanks... didn't know this.
quoted
+ u8 buf[2] ____cacheline_aligned;
+ u32 tune_cap;
+};
+
+static const struct iio_chan_spec as3935_channels[] = {
+ {
+ .type = IIO_PROXIMITY,
+ .info_mask_separate =
+ BIT(IIO_CHAN_INFO_RAW),
+ .scan_index = 0,
+ .scan_type = {
+ .sign = 'u',
+ .realbits = 6,
+ .storagebits = 8,
+ },
+ },
+ IIO_CHAN_SOFT_TIMESTAMP(1),
+};
+
+static int as3935_read(struct as3935_state *st, unsigned int reg, int
*val)
+{
+ u8 cmd;
+ int ret;
+
+ cmd = (AS3935_READ_DATA | AS3935_ADDRESS(reg)) >> 8;
+ ret = spi_w8r8(st->spi, cmd);
+ if (ret < 0)
+ return ret;
+ *val = ret;
+
+ return 0;
+};
+
+static int as3935_write(struct as3935_state *st,
+ unsigned int reg,
+ unsigned int val)
+{
I wouldn't bother with the local pointer copy. Slightly
obscures what is giong on to save a few character.
quoted
+ u8 *buf = st->buf;
+
+ buf[0] = (AS3935_WRITE_DATA | AS3935_ADDRESS(reg)) >> 8;
+ buf[1] = val;
+
+ return spi_write(st->spi, (u8 *) buf, 2);
Why the typecast? It's already a u8 *
quoted
+};
+
+static ssize_t as3935_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 as3935_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,
+ as3935_gain_boost_show, as3935_gain_boost_store, 0);
+
+
+static struct attribute *as3935_attributes[] = {
+ &iio_dev_attr_gain_boost.dev_attr.attr,
So what is this really? Could it be considered a calibration scale?
Or a straight _scale? Is it effecting the measurement, or
the sensitivity to make a measurement? If the second then
we probably want a more general naming.
Perhaps
in_detectionsensitivy or similar (that's a quick random suggestion
- I'd prefer something better thought out ;)
quoted
+ 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);
+ int ret;
+
+ if (m != IIO_CHAN_INFO_RAW)
+ return -EINVAL;
+
+ *val2 = 0;
+ ret = as3935_read(st, AS3935_DATA, val);
+ if (ret)
+ return ret;
+ *val *= 1000;
+
+ return IIO_VAL_INT;
+}
+
+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,
+};
These are the defaults - don't provide any and you'll get the same thing
(see industrialio-triggered-buffer.c)
Ok cruft will be removed in next series
quoted
+
+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;
+ val *= 1000;
+
+ iio_push_to_buffers_with_timestamp(indio_dev, &val,
pf->timestamp);
+err_read:
+ iio_trigger_notify_done(indio_dev->trig);
+
+ 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;
+ int val;
+
+ st = container_of(work, struct as3935_state, work.work);
+
+ as3935_read(st, AS3935_INT, &val);
+ val &= AS3935_INT_MASK;
+
+ switch (val) {
+ case AS3935_EVENT_INT:
+ iio_trigger_poll(st->trig, iio_get_time_ns());
+ break;
+ case AS3935_NOISE_INT:
This could be provided as an event perhaps? Not sure, but splurging in
the log is probably going to be missed.
quoted
+ dev_warn(&st->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);
+
/*
* Delay..
quoted
+ /* Delay work for >2 milliseconds after an interrupt to allow
+ * estimated distance to recalculated.
+ */
+
+ schedule_delayed_work(&st->work, msecs_to_jiffies(3));
+
+ return IRQ_HANDLED;
+}
+
+static void calibrate_as3935(struct as3935_state *st)
+{
+ mutex_lock(&st->lock);
+
+ /* mask disturber interrupt bit */
+ as3935_write(st, AS3935_INT, 1<<5);
+
+ as3935_write(st, AS3935_CALIBRATE, 0x96);
1 << 5 as it's a binary operator.
quoted
+ as3935_write(st, AS3935_TUNE_CAP, 1<<5 | (st->tune_cap /
TUNE_CAP_DIV));
+
+ mdelay(2);
+ as3935_write(st, AS3935_TUNE_CAP, (st->tune_cap / TUNE_CAP_DIV));
+
+ mutex_unlock(&st->lock);
+}
+
+#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;
+
+ mutex_lock(&st->lock);
+ ret = as3935_read(st, AS3935_AFE_GAIN, &val);
+ if (ret)
+ goto err_suspend;
+ val |= AS3935_AFE_PWR_BIT;
+
+ ret = as3935_write(st, AS3935_AFE_GAIN, val);
+
+err_suspend:
+ mutex_unlock(&st->lock);
+
+ return ret;
+}
+
+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;
+
+ mutex_lock(&st->lock);
+ ret = as3935_read(st, AS3935_AFE_GAIN, &val);
+ if (ret)
+ goto err_resume;
+ val &= ~AS3935_AFE_PWR_BIT;
+ ret = as3935_write(st, AS3935_AFE_GAIN, val);
+
+err_resume:
+ mutex_unlock(&st->lock);
+
+ return ret;
+}
+#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 ret;
+
... is specified?
quoted
+ /* Be sure lightning event interrupt */
+ if (!spi->irq) {
+ dev_err(&spi->dev, "unable to get event interrupt\n");
+ 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);
+
+ ret = of_property_read_u32(np,
+ "ams,tuning-capacitor-pf", &st->tune_cap);
+ if (ret) {
+ st->tune_cap = 0;
+ dev_warn(&spi->dev,
+ "no tuning-capacitor-pf set, defaulting to %d",
+ st->tune_cap);
+ }
+
+ if (st->tune_cap > MAX_PF_CAP) {
+ dev_err(&spi->dev,
+ "wrong tuning-capacitor-pf 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->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");
This will unroll the triggered_buffer_setup that has errored out.
Hence you will unregister a buffer that was never registered.
This should have it's own label to goto that only unregisters the
trigger.
quoted
+ goto unregister_trigger;
+ }
+
+ calibrate_as3935(st);
+
+ ret = devm_request_irq(&spi->dev, spi->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 unregister_trigger;
+ }
+
+ ret = iio_device_register(indio_dev);
+ if (ret < 0) {
+ dev_err(&spi->dev, "unable to register device\n");
+ goto unregister_trigger;
+ }
+ return 0;
+
+unregister_trigger:
These should be in the opposite order to conform to standard
error unrolling (undo things in reverse order.
Oops... I knew that..
quoted
+ iio_trigger_unregister(st->trig);
+ 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);
+ struct as3935_state *st = iio_priv(indio_dev);
+
+ iio_device_unregister(indio_dev);
+ iio_triggered_buffer_cleanup(indio_dev);
+ iio_trigger_unregister(st->trig);
+
+ 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 [off-list ref]");
+MODULE_DESCRIPTION("AS3935 lightning sensor");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("spi:as3935");