On Tue, Oct 20, 2015 at 2:50 PM, Crt Mori <cmo@xxxxxxxxxxx> wrote: > On 20 October 2015 at 12:53, Daniel Baluta <daniel.baluta@xxxxxxxxx> wrote: >> Signed-off-by: Daniel Baluta <daniel.baluta@xxxxxxxxx> >> --- >> Documentation/ABI/testing/configfs-iio | 21 ++++++++ >> Documentation/iio/iio_configfs.txt | 93 ++++++++++++++++++++++++++++++++++ >> 2 files changed, 114 insertions(+) >> create mode 100644 Documentation/ABI/testing/configfs-iio >> create mode 100644 Documentation/iio/iio_configfs.txt >> >> diff --git a/Documentation/ABI/testing/configfs-iio b/Documentation/ABI/testing/configfs-iio >> new file mode 100644 >> index 0000000..2483756 >> --- /dev/null >> +++ b/Documentation/ABI/testing/configfs-iio >> @@ -0,0 +1,21 @@ >> +What: /config/iio >> +Date: October 2015 >> +KernelVersion: 4.4 >> +Contact: linux-iio@xxxxxxxxxxxxxxx >> +Description: >> + This represents Industrial IO configuration entry point >> + directory. It contains sub-groups corresponding to IIO >> + objects. >> + >> +What: /config/iio/triggers >> +Date: October 2015 >> +KernelVersion: 4.4 >> +Description: >> + Industrial IO software triggers directory. >> + >> +What: /config/iio/triggers/hrtimers >> +Date: October 2015 >> +KernelVersion: 4.4 >> +Description: >> + High resolution timers directory. Creating a directory here >> + will result in creating a hrtimer trigger in the IIO subsystem. >> diff --git a/Documentation/iio/iio_configfs.txt b/Documentation/iio/iio_configfs.txt >> new file mode 100644 >> index 0000000..f0add35 >> --- /dev/null >> +++ b/Documentation/iio/iio_configfs.txt >> @@ -0,0 +1,93 @@ >> +Industrial IIO configfs support >> + >> +1. Overview >> + >> +Configfs is a filesystem-based manager of kernel objects. IIO uses some >> +objects that could be easily configured using configfs (e.g.: devices, >> +triggers). >> + >> +See Documentation/filesystems/configfs/configfs.txt for more information >> +about how configfs works. >> + >> +2. Usage >> + >> +In order to use configfs support in IIO we need to select it at compile >> +time via CONFIG_IIO_CONFIGFS config option. >> + >> +Then, mount the configfs filesystem (usually under /config directory): >> + >> +$ mkdir /config >> +$ mount -t configfs none /config >> + >> +At this point, all default IIO groups will be created and can be accessed >> +under /config/iio. Next chapters will describe available IIO configuration >> +objects. >> + >> +3. Software triggers >> + >> +One of the IIO default configfs groups is the "triggers" group. It is >> +automagically accessible when the configfs is mounted and can be found > automagically is probably automatically? Automagically is more fun :). http://www.urbandictionary.com/define.php?term=automagically >> +under /config/iio/triggers. >> + >> +IIO software triggers implementation offers support for creating multiple >> +trigger types. A new trigger type is usually implemented as a separate >> +kernel module following the interface in include/linux/iio/sw_trigger.h: >> + >> +/* >> + * drivers/iio/trigger/iio-trig-sample.c >> + * sample kernel module implementing a new trigger type >> + */ >> +#include <linux/iio/sw_trigger.h> >> + >> + >> +static struct iio_sw_trigger *iio_trig_sample_probe(const char *name) >> +{ >> + /* >> + * This allocates and registers an IIO trigger plus other >> + * trigger type specific initialization. >> + */ >> +} >> + >> +static int iio_trig_hrtimer_remove(struct iio_sw_trigger *swt) >> +{ >> + /* >> + * This undoes the actions in iio_trig_sample_probe >> + */ >> +} >> + >> +static const struct iio_sw_trigger_ops iio_trig_sample_ops = { >> + .probe = iio_trig_sample_probe, >> + .remove = iio_trig_sample_remove, >> +}; >> + >> +static struct iio_sw_trigger_type iio_trig_sample = { >> + .name = "trig-sample", >> + .owner = THIS_MODULE, >> + .ops = &iio_trig_sample_ops, >> +}; >> + >> +module_iio_sw_trigger_driver(iio_trig_sample); >> + >> +Each trigger type has its own directory under /config/iio/triggers. Loading >> +iio-trig-sample module will create 'trig-sample' trigger type directory >> +/config/iio/triggers/trig-sample. >> + >> +We support the following interrupt sources (trigger types): >> + * hrtimer, uses high resolution timers as interrupt source >> + >> +3.1 Hrtimer triggers creation and destruction >> + >> +Loading iio-trig-hrtimer module will register hrtimer trigger types allowing >> +users to create hrtimer triggers under /config/iio/triggers/hrtimer. >> + >> +e.g: >> + >> +$ mkdir /config/triggers/hrtimer/instance1 >> +$ rmdir /config/triggers/hrtimer/instance1 >> + >> +Each trigger can have one or more attributes specific to the trigger type. >> + >> +3.2 "hrtimer" trigger types attributes >> + >> +"hrtimer" trigger type doesn't have any configurable attribute from /config dir. >> +It does introduce the sampling_frequency attribute to trigger directory. >> -- > -- > To unsubscribe from this list: send the line "unsubscribe linux-iio" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
