diff options
Diffstat (limited to 'Documentation/iio')
| -rw-r--r-- | Documentation/iio/ep93xx_adc.rst (renamed from Documentation/iio/ep93xx_adc.txt) | 15 | ||||
| -rw-r--r-- | Documentation/iio/iio_configfs.rst (renamed from Documentation/iio/iio_configfs.txt) | 52 | ||||
| -rw-r--r-- | Documentation/iio/index.rst | 12 |
3 files changed, 55 insertions, 24 deletions
diff --git a/Documentation/iio/ep93xx_adc.txt b/Documentation/iio/ep93xx_adc.rst index 23053e7817bd..4fd8dea3f6b8 100644 --- a/Documentation/iio/ep93xx_adc.txt +++ b/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 | +-----------------+---------------+ diff --git a/Documentation/iio/iio_configfs.txt b/Documentation/iio/iio_configfs.rst index 4e5f101837a8..ecbfdb3afef7 100644 --- a/Documentation/iio/iio_configfs.txt +++ b/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, @@ -10,20 +13,22 @@ 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 + $ 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 @@ -31,40 +36,40 @@ 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 - * sample kernel module implementing a new trigger type - */ -#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) -{ + 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) -{ + 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 = { + 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 = { + 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); @@ -73,21 +78,24 @@ 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 + $ mkdir /config/iio/triggers/hrtimer/instance1 + $ 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. diff --git a/Documentation/iio/index.rst b/Documentation/iio/index.rst new file mode 100644 index 000000000000..58b7a4ebac51 --- /dev/null +++ b/Documentation/iio/index.rst @@ -0,0 +1,12 @@ +.. SPDX-License-Identifier: GPL-2.0 + +============== +Industrial I/O +============== + +.. toctree:: + :maxdepth: 1 + + iio_configfs + + ep93xx_adc |