docs: iio: convert to ReST

Rename the iio documentation files to ReST, add an
index for them and adjust in order to produce a nice html
output via the Sphinx build system.

At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Documentation/iio/ep93xx_adc.rst

@@ -1,12 +1,16 @@
-Cirrus Logic EP93xx ADC driver.
+==============================
+Cirrus Logic EP93xx ADC driver
+==============================
 
 1. Overview
+===========
 
 The driver is intended to work on both low-end (EP9301, EP9302) devices with
 5-channel ADC and high-end (EP9307, EP9312, EP9315) devices with 10-channel
 touchscreen/ADC module.
 
 2. Channel numbering
+====================
 
 Numbering scheme for channels 0..4 is defined in EP9301 and EP9302 datasheets.
 EP9307, EP9312 and EP9312 have 3 channels more (total 8), but the numbering is
@@ -17,13 +21,20 @@ Assuming ep93xx_adc is IIO device0, you'd find the following entries under
 
   +-----------------+---------------+
   | sysfs entry     | ball/pin name |
-  +-----------------+---------------+
+  +=================+===============+
   | in_voltage0_raw | YM            |
+  +-----------------+---------------+
   | in_voltage1_raw | SXP           |
+  +-----------------+---------------+
   | in_voltage2_raw | SXM           |
+  +-----------------+---------------+
   | in_voltage3_raw | SYP           |
+  +-----------------+---------------+
   | in_voltage4_raw | SYM           |
+  +-----------------+---------------+
   | in_voltage5_raw | XP            |
+  +-----------------+---------------+
   | in_voltage6_raw | XM            |
+  +-----------------+---------------+
   | in_voltage7_raw | YP            |
   +-----------------+---------------+

Documentation/iio/iio_configfs.rst

@@ -1,6 +1,9 @@
+===============================
 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,
@@ -10,11 +13,12 @@ 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):
+Then, mount the configfs filesystem (usually under /config directory)::
 
   $ mkdir /config
   $ mount -t configfs none /config
@@ -24,6 +28,7 @@ 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
@@ -31,7 +36,7 @@ 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:
+kernel module following the interface in include/linux/iio/sw_trigger.h::
 
   /*
    * drivers/iio/trigger/iio-trig-sample.c
@@ -73,14 +78,16 @@ 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:
+e.g::
 
   $ mkdir /config/iio/triggers/hrtimer/instance1
   $ rmdir /config/iio/triggers/hrtimer/instance1
@@ -88,6 +95,7 @@ $ rmdir /config/iio/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.

Documentation/iio/index.rst

@@ -0,0 +1,12 @@
+:orphan:
+
+==============
+Industrial I/O
+==============
+
+.. toctree::
+   :maxdepth: 1
+
+   iio_configfs
+
+   ep93xx_adc

drivers/iio/Kconfig

@@ -27,7 +27,7 @@ config IIO_CONFIGFS
 	help
 	  This allows configuring various IIO bits through configfs
 	  (e.g. software triggers). For more info see
-	  Documentation/iio/iio_configfs.txt.
+	  Documentation/iio/iio_configfs.rst.
 
 config IIO_TRIGGER
 	bool "Enable triggered sampling support"