Re: [PATCH v4 1/4] iio: Support triggered events

From: Vladimir Barinov
Date: Thu Aug 20 2015 - 15:44:10 EST

Verified event and buffer polling works concurrently on the same trigger with hi-8435.
The buffer interface part for hi-8435 was not sent.

On 20.08.2015 22:37, Vladimir Barinov wrote:
Support triggered events.

This is useful for chips that don't have their own interrupt sources.
It allows to use generic/standalone iio triggers for those drivers.

Signed-off-by: Vladimir Barinov <vladimir.barinov@xxxxxxxxxxxxxxxxxx>
---
Changes in version 2:
- initially added
Changes in version 3:
- fixed grammar in patch description
- changed license header to match "GNU Public License v2 or later"
Changes in version 4:
- added pollfunc_event to separate triggering buffer and event
interfaces. This allows runnig both from the same trigger
- removed 'currentmode' for triggered buffer since useless
- renamed parameters of iio_triggered_event_setup

drivers/iio/Kconfig | 6 +++
drivers/iio/Makefile | 1 +
drivers/iio/industrialio-core.c | 4 +-
drivers/iio/industrialio-trigger.c | 12 +++++-
drivers/iio/industrialio-triggered-event.c | 68 ++++++++++++++++++++++++++++++
include/linux/iio/iio.h | 3 ++
include/linux/iio/triggered_event.h | 11 +++++
7 files changed, 101 insertions(+), 4 deletions(-)
create mode 100644 drivers/iio/industrialio-triggered-event.c
create mode 100644 include/linux/iio/triggered_event.h

diff --git a/drivers/iio/Kconfig b/drivers/iio/Kconfig
index 4011eff..8fcc92f 100644
--- a/drivers/iio/Kconfig
+++ b/drivers/iio/Kconfig
@@ -58,6 +58,12 @@ config IIO_CONSUMERS_PER_TRIGGER
This value controls the maximum number of consumers that a
given trigger may handle. Default is 2.
+config IIO_TRIGGERED_EVENT
+ tristate
+ select IIO_TRIGGER
+ help
+ Provides helper functions for setting up triggered events.
+
source "drivers/iio/accel/Kconfig"
source "drivers/iio/adc/Kconfig"
source "drivers/iio/amplifiers/Kconfig"
diff --git a/drivers/iio/Makefile b/drivers/iio/Makefile
index 698afc2..40dc13e 100644
--- a/drivers/iio/Makefile
+++ b/drivers/iio/Makefile
@@ -9,6 +9,7 @@ industrialio-$(CONFIG_IIO_TRIGGER) += industrialio-trigger.o
industrialio-$(CONFIG_IIO_BUFFER_CB) += buffer_cb.o
obj-$(CONFIG_IIO_TRIGGERED_BUFFER) += industrialio-triggered-buffer.o
+obj-$(CONFIG_IIO_TRIGGERED_EVENT) += industrialio-triggered-event.o
obj-$(CONFIG_IIO_KFIFO_BUF) += kfifo_buf.o
obj-y += accel/
diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index b3fcc2c..2c3b6a1 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -962,7 +962,7 @@ static void iio_device_unregister_sysfs(struct iio_dev *indio_dev)
static void iio_dev_release(struct device *device)
{
struct iio_dev *indio_dev = dev_to_iio_dev(device);
- if (indio_dev->modes & INDIO_BUFFER_TRIGGERED)
+ if (indio_dev->modes & (INDIO_BUFFER_TRIGGERED | INDIO_EVENT_TRIGGERED))
iio_device_unregister_trigger_consumer(indio_dev);
iio_device_unregister_eventset(indio_dev);
iio_device_unregister_sysfs(indio_dev);
@@ -1241,7 +1241,7 @@ int iio_device_register(struct iio_dev *indio_dev)
"Failed to register event set\n");
goto error_free_sysfs;
}
- if (indio_dev->modes & INDIO_BUFFER_TRIGGERED)
+ if (indio_dev->modes & (INDIO_BUFFER_TRIGGERED | INDIO_EVENT_TRIGGERED))
iio_device_register_trigger_consumer(indio_dev);
if ((indio_dev->modes & INDIO_ALL_BUFFER_MODES) &&
diff --git a/drivers/iio/industrialio-trigger.c b/drivers/iio/industrialio-trigger.c
index 570606c..ae2806a 100644
--- a/drivers/iio/industrialio-trigger.c
+++ b/drivers/iio/industrialio-trigger.c
@@ -366,10 +366,18 @@ static ssize_t iio_trigger_write_current(struct device *dev,
indio_dev->trig = trig;
- if (oldtrig)
+ if (oldtrig) {
+ if (indio_dev->modes & INDIO_EVENT_TRIGGERED)
+ iio_trigger_detach_poll_func(oldtrig,
+ indio_dev->pollfunc_event);
iio_trigger_put(oldtrig);
- if (indio_dev->trig)
+ }
+ if (indio_dev->trig) {
iio_trigger_get(indio_dev->trig);
+ if (indio_dev->modes & INDIO_EVENT_TRIGGERED)
+ iio_trigger_attach_poll_func(indio_dev->trig,
+ indio_dev->pollfunc_event);
+ }
return len;
}
diff --git a/drivers/iio/industrialio-triggered-event.c b/drivers/iio/industrialio-triggered-event.c
new file mode 100644
index 0000000..8cc254f
--- /dev/null
+++ b/drivers/iio/industrialio-triggered-event.c
@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) 2015 Cogent Embedded, Inc.
+ *
+ * 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/export.h>
+#include <linux/module.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/triggered_event.h>
+#include <linux/iio/trigger_consumer.h>
+
+/**
+ * iio_triggered_event_setup() - Setup pollfunc_event for triggered event
+ * @indio_dev: IIO device structure
+ * @h: Function which will be used as pollfunc_event top half
+ * @thread: Function which will be used as pollfunc_event bottom half
+ *
+ * This function combines some common tasks which will normally be performed
+ * when setting up a triggered event. It will allocate the pollfunc_event and
+ * set mode to use it for triggered event.
+ *
+ * Before calling this function the indio_dev structure should already be
+ * completely initialized, but not yet registered. In practice this means that
+ * this function should be called right before iio_device_register().
+ *
+ * To free the resources allocated by this function call
+ * iio_triggered_event_cleanup().
+ */
+int iio_triggered_event_setup(struct iio_dev *indio_dev,
+ irqreturn_t (*h)(int irq, void *p),
+ irqreturn_t (*thread)(int irq, void *p))
+{
+ indio_dev->pollfunc_event = iio_alloc_pollfunc(h,
+ thread,
+ IRQF_ONESHOT,
+ indio_dev,
+ "%s_consumer%d",
+ indio_dev->name,
+ indio_dev->id);
+ if (indio_dev->pollfunc_event == NULL)
+ return -ENOMEM;
+
+ /* Flag that events polling is possible */
+ indio_dev->modes |= INDIO_EVENT_TRIGGERED;
+
+ return 0;
+}
+EXPORT_SYMBOL(iio_triggered_event_setup);
+
+/**
+ * iio_triggered_event_cleanup() - Free resources allocated by iio_triggered_event_setup()
+ * @indio_dev: IIO device structure
+ */
+void iio_triggered_event_cleanup(struct iio_dev *indio_dev)
+{
+ indio_dev->modes &= ~INDIO_EVENT_TRIGGERED;
+ iio_dealloc_pollfunc(indio_dev->pollfunc_event);
+}
+EXPORT_SYMBOL(iio_triggered_event_cleanup);
+
+MODULE_AUTHOR("Vladimir Barinov");
+MODULE_DESCRIPTION("IIO helper functions for setting up triggered events");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h
index 7bb7f67..19c94c9 100644
--- a/include/linux/iio/iio.h
+++ b/include/linux/iio/iio.h
@@ -294,6 +294,7 @@ static inline s64 iio_get_time_ns(void)
#define INDIO_BUFFER_TRIGGERED 0x02
#define INDIO_BUFFER_SOFTWARE 0x04
#define INDIO_BUFFER_HARDWARE 0x08
+#define INDIO_EVENT_TRIGGERED 0x10
#define INDIO_ALL_BUFFER_MODES \
(INDIO_BUFFER_TRIGGERED | INDIO_BUFFER_HARDWARE | INDIO_BUFFER_SOFTWARE)
@@ -457,6 +458,7 @@ struct iio_buffer_setup_ops {
* @scan_index_timestamp:[INTERN] cache of the index to the timestamp
* @trig: [INTERN] current device trigger (buffer modes)
* @pollfunc: [DRIVER] function run on trigger being received
+ * @pollfunc_event: [DRIVER] function run on events trigger being received
* @channels: [DRIVER] channel specification structure table
* @num_channels: [DRIVER] number of channels specified in @channels.
* @channel_attr_list: [INTERN] keep track of automatically created channel
@@ -495,6 +497,7 @@ struct iio_dev {
unsigned scan_index_timestamp;
struct iio_trigger *trig;
struct iio_poll_func *pollfunc;
+ struct iio_poll_func *pollfunc_event;
struct iio_chan_spec const *channels;
int num_channels;
diff --git a/include/linux/iio/triggered_event.h b/include/linux/iio/triggered_event.h
new file mode 100644
index 0000000..8fe8537
--- /dev/null
+++ b/include/linux/iio/triggered_event.h
@@ -0,0 +1,11 @@
+#ifndef _LINUX_IIO_TRIGGERED_EVENT_H_
+#define _LINUX_IIO_TRIGGERED_EVENT_H_
+
+#include <linux/interrupt.h>
+
+int iio_triggered_event_setup(struct iio_dev *indio_dev,
+ irqreturn_t (*h)(int irq, void *p),
+ irqreturn_t (*thread)(int irq, void *p));
+void iio_triggered_event_cleanup(struct iio_dev *indio_dev);
+
+#endif

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