linux-kernel - [PATCH v4 4/4] iio: Documentation: Add IIO configfs documentation

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 20 Apr 2015 17:02:43 +0300
From:	Daniel Baluta <daniel.baluta@...el.com>
To:	jic23@...nel.org
Cc:	jlbec@...lplan.org, lars@...afoo.de, knaack.h@....de,
	linux-kernel@...r.kernel.org, linux-iio@...r.kernel.org,
	octavian.purdila@...el.com, pebolle@...cali.nl,
	patrick.porlan@...el.com, adriana.reus@...el.com,
	constantin.musca@...el.com, marten@...uitiveaerial.com
Subject: [PATCH v4 4/4] iio: Documentation: Add IIO configfs documentation

Signed-off-by: Daniel Baluta <daniel.baluta@...el.com>
---
 Documentation/iio/iio_configfs.txt | 67 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 67 insertions(+)
 create mode 100644 Documentation/iio/iio_configfs.txt

diff --git a/Documentation/iio/iio_configfs.txt b/Documentation/iio/iio_configfs.txt
new file mode 100644
index 0000000..1aa66d1
--- /dev/null
+++ b/Documentation/iio/iio_configfs.txt
@@ -0,0 +1,67 @@
+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" groups. It is
+automagically accessible when the configfs is mounted and can be found
+under /config/iio/triggers.
+
+Software triggers are created under /config/iio/triggers directory. A sofware
+trigger name MUST be of the following form:
+	* <trigger-type>-<trigger-name>:
+Where:
+	* <trigger-type>, specifies the interrupt source (e.g: hrtimer)
+	* <trigger-name>, spefcifies the IIO device trigger name
+
+We support now to following interrupt sources (trigger types):
+	* hrtimer, uses high resolution timers as interrupt source
+
+3.1 Software triggers creation and destruction
+
+As simply as:
+
+$ mkdir /config/triggers/<trigger-type>-<trigger-name>
+$ rmdir /config/triggers/<trigger-type>-<trigger-name>
+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 has only one attribute:
+
+$ ls /config/triggers/hrtimer-instance1
+sampling_frequency
+
+sampling_frequency - represents the period in Hz between two consecutive
+iio_trigger_poll calls. By default it is set to 100Hz.
+
+4. Further work
+
+* add "sysfs" trigger type
-- 
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/