From f9a7e9b2f074218ef7e3afcdaa71f6804fd36c84 Mon Sep 17 00:00:00 2001 From: Michael Hennerich Date: Mon, 7 Feb 2011 11:05:46 +0100 Subject: [PATCH] Staging: IIO: TRIGGER: New sysfs based trigger This patch adds a new trigger that can be invoked by writing the sysfs file: trigger_now. This approach can be valuable during automated testing or in situations, where other trigger methods are not applicable. For example no RTC or spare GPIOs. Last but not least we can allow user space applications to produce triggers. IIO: TRIGGER: Apply review feedback by Greg Kroah-Hartman Changes since v1: Add sysfs documentation. Change license notice. Add module alias. Add more Kconfig help text Signed-off-by: Michael Hennerich Acked-by: Jonathan Cameron Signed-off-by: Greg Kroah-Hartman --- .../Documentation/sysfs-bus-iio-trigger-sysfs | 11 ++ drivers/staging/iio/trigger/Kconfig | 10 ++ drivers/staging/iio/trigger/Makefile | 1 + drivers/staging/iio/trigger/iio-trig-sysfs.c | 108 ++++++++++++++++++ 4 files changed, 130 insertions(+) create mode 100644 drivers/staging/iio/Documentation/sysfs-bus-iio-trigger-sysfs create mode 100644 drivers/staging/iio/trigger/iio-trig-sysfs.c diff --git a/drivers/staging/iio/Documentation/sysfs-bus-iio-trigger-sysfs b/drivers/staging/iio/Documentation/sysfs-bus-iio-trigger-sysfs new file mode 100644 index 000000000000..5235e6c749ab --- /dev/null +++ b/drivers/staging/iio/Documentation/sysfs-bus-iio-trigger-sysfs @@ -0,0 +1,11 @@ +What: /sys/bus/iio/devices/triggerX/trigger_now +KernelVersion: 2.6.38 +Contact: linux-iio@vger.kernel.org +Description: + This file is provided by the iio-trig-sysfs stand-alone trigger + driver. Writing this file with any value triggers an event + driven driver, associated with this trigger, to capture data + into an in kernel buffer. This approach can be valuable during + automated testing or in situations, where other trigger methods + are not applicable. For example no RTC or spare GPIOs. + X is the IIO index of the trigger. diff --git a/drivers/staging/iio/trigger/Kconfig b/drivers/staging/iio/trigger/Kconfig index d842a584a3af..3a82013e2b8b 100644 --- a/drivers/staging/iio/trigger/Kconfig +++ b/drivers/staging/iio/trigger/Kconfig @@ -18,4 +18,14 @@ config IIO_GPIO_TRIGGER help Provides support for using GPIO pins as IIO triggers. +config IIO_SYSFS_TRIGGER + tristate "SYSFS trigger" + depends on SYSFS + help + Provides support for using SYSFS entry as IIO triggers. + If unsure, say N (but it's safe to say "Y"). + + To compile this driver as a module, choose M here: the + module will be called iio-trig-sysfs. + endif # IIO_TRIGGER diff --git a/drivers/staging/iio/trigger/Makefile b/drivers/staging/iio/trigger/Makefile index 10aeca5e347a..504b9c07970c 100644 --- a/drivers/staging/iio/trigger/Makefile +++ b/drivers/staging/iio/trigger/Makefile @@ -4,3 +4,4 @@ obj-$(CONFIG_IIO_PERIODIC_RTC_TRIGGER) += iio-trig-periodic-rtc.o obj-$(CONFIG_IIO_GPIO_TRIGGER) += iio-trig-gpio.o +obj-$(CONFIG_IIO_SYSFS_TRIGGER) += iio-trig-sysfs.o diff --git a/drivers/staging/iio/trigger/iio-trig-sysfs.c b/drivers/staging/iio/trigger/iio-trig-sysfs.c new file mode 100644 index 000000000000..127a2a33e4db --- /dev/null +++ b/drivers/staging/iio/trigger/iio-trig-sysfs.c @@ -0,0 +1,108 @@ +/* + * Copyright 2011 Analog Devices Inc. + * + * Licensed under the GPL-2. + * + */ + +#include +#include +#include +#include + +#include "../iio.h" +#include "../trigger.h" + +static ssize_t iio_sysfs_trigger_poll(struct device *dev, + struct device_attribute *attr, const char *buf, size_t count) +{ + struct iio_trigger *trig = dev_get_drvdata(dev); + iio_trigger_poll(trig, 0); + + return count; +} + +static DEVICE_ATTR(trigger_now, S_IWUSR, NULL, iio_sysfs_trigger_poll); +static IIO_TRIGGER_NAME_ATTR; + +static struct attribute *iio_sysfs_trigger_attrs[] = { + &dev_attr_trigger_now.attr, + &dev_attr_name.attr, + NULL, +}; + +static const struct attribute_group iio_sysfs_trigger_attr_group = { + .attrs = iio_sysfs_trigger_attrs, +}; + +static int __devinit iio_sysfs_trigger_probe(struct platform_device *pdev) +{ + struct iio_trigger *trig; + int ret; + + trig = iio_allocate_trigger(); + if (!trig) { + ret = -ENOMEM; + goto out1; + } + + trig->control_attrs = &iio_sysfs_trigger_attr_group; + trig->owner = THIS_MODULE; + trig->name = kasprintf(GFP_KERNEL, "sysfstrig%d", pdev->id); + if (trig->name == NULL) { + ret = -ENOMEM; + goto out2; + } + + ret = iio_trigger_register(trig); + if (ret) + goto out3; + + platform_set_drvdata(pdev, trig); + + return 0; +out3: + kfree(trig->name); +out2: + iio_put_trigger(trig); +out1: + + return ret; +} + +static int __devexit iio_sysfs_trigger_remove(struct platform_device *pdev) +{ + struct iio_trigger *trig = platform_get_drvdata(pdev); + + iio_trigger_unregister(trig); + kfree(trig->name); + iio_put_trigger(trig); + + return 0; +} + +static struct platform_driver iio_sysfs_trigger_driver = { + .driver = { + .name = "iio_sysfs_trigger", + .owner = THIS_MODULE, + }, + .probe = iio_sysfs_trigger_probe, + .remove = __devexit_p(iio_sysfs_trigger_remove), +}; + +static int __init iio_sysfs_trig_init(void) +{ + return platform_driver_register(&iio_sysfs_trigger_driver); +} +module_init(iio_sysfs_trig_init); + +static void __exit iio_sysfs_trig_exit(void) +{ + platform_driver_unregister(&iio_sysfs_trigger_driver); +} +module_exit(iio_sysfs_trig_exit); + +MODULE_AUTHOR("Michael Hennerich "); +MODULE_DESCRIPTION("Sysfs based trigger for the iio subsystem"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:iio-trig-sysfs"); -- 2.20.1