diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2015-08-31 09:24:06 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-08-31 09:24:06 -0700 |
commit | 2f37d65a6a5c360ba0c386a6aa0d2afcbda7060d (patch) | |
tree | a2c0ab8b6d7fd7ea57d0140f22a79337064d761e /Documentation | |
parent | 1af115d675f323afee1e64650277a9b170845b81 (diff) | |
parent | 415bcb5c6eff630967baa4e671cebe883d83ee79 (diff) | |
download | linux-2f37d65a6a5c360ba0c386a6aa0d2afcbda7060d.tar.bz2 |
Merge tag 'staging-4.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging
Pull staging driver updates from Greg KH:
"Here is the big staging driver updates for 4.3-rc1.
Lots of things all over the place, almost all of them trivial fixups
and changes. The usual IIO updates and new drivers and we have added
the MOST driver subsystem which is getting cleaned up in the tree.
The ozwpan driver is finally being deleted as it is obviously
abandoned and no one cares about it.
Full details are in the shortlog, and all of these have been in
linux-next with no reported issues"
* tag 'staging-4.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (912 commits)
staging/lustre/o2iblnd: remove references to ib_reg_phsy_mr()
staging: wilc1000: fix build warning with setup_timer()
staging: wilc1000: remove DECLARE_WILC_BUFFER()
staging: wilc1000: remove void function return statements that are not useful
staging: wilc1000: coreconfigurator.c: fix kmalloc error check
staging: wilc1000: coreconfigurator.c: use kmalloc instead of WILC_MALLOC
staging: wilc1000: remove unused codes of gps8ConfigPacket
staging: wilc1000: remove unnecessary void pointer cast
staging: wilc1000: remove WILC_NEW and WILC_NEW_EX
staging: wilc1000: use kmalloc instead of WILC_NEW
staging: wilc1000: Process WARN, INFO options of debug levels from user
staging: wilc1000: remove unneeded tstrWILC_MsgQueueAttrs typedef
staging: wilc1000: delete wilc_osconfig.h
staging: wilc1000: delete wilc_log.h
staging: wilc1000: delete wilc_timer.h
staging: wilc1000: remove WILC_TimerStart()
staging: wilc1000: remove WILC_TimerCreate()
staging: wilc1000: remove WILC_TimerDestroy()
staging: wilc1000: remove WILC_TimerStop()
staging: wilc1000: remove tstrWILC_TimerAttrs typedef
...
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/ABI/testing/sysfs-bus-iio | 18 | ||||
-rw-r--r-- | Documentation/ABI/testing/sysfs-bus-iio-trigger-sysfs | 9 | ||||
-rw-r--r-- | Documentation/DocBook/Makefile | 2 | ||||
-rw-r--r-- | Documentation/DocBook/iio.tmpl | 697 | ||||
-rw-r--r-- | Documentation/devicetree/bindings/iio/adc/mcp320x.txt | 1 | ||||
-rw-r--r-- | Documentation/devicetree/bindings/iio/adc/vf610-adc.txt | 5 | ||||
-rw-r--r-- | Documentation/devicetree/bindings/iio/magnetometer/mmc35240.txt | 13 | ||||
-rw-r--r-- | Documentation/devicetree/bindings/iio/st-sensors.txt | 2 | ||||
-rw-r--r-- | Documentation/devicetree/bindings/staging/iio/adc/mxs-lradc.txt | 2 | ||||
-rw-r--r-- | Documentation/fb/sm712fb.txt | 31 |
10 files changed, 768 insertions, 12 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio index 70c9b1ac66db..42d360fe66a5 100644 --- a/Documentation/ABI/testing/sysfs-bus-iio +++ b/Documentation/ABI/testing/sysfs-bus-iio @@ -413,6 +413,11 @@ Description: to compute the calories burnt by the user. What: /sys/bus/iio/devices/iio:deviceX/in_accel_scale_available +What: /sys/.../iio:deviceX/in_anglvel_scale_available +What: /sys/.../iio:deviceX/in_magn_scale_available +What: /sys/.../iio:deviceX/in_illuminance_scale_available +What: /sys/.../iio:deviceX/in_intensity_scale_available +What: /sys/.../iio:deviceX/in_proximity_scale_available What: /sys/.../iio:deviceX/in_voltageX_scale_available What: /sys/.../iio:deviceX/in_voltage-voltage_scale_available What: /sys/.../iio:deviceX/out_voltageX_scale_available @@ -488,7 +493,7 @@ Contact: linux-iio@vger.kernel.org Description: Specifies the output powerdown mode. DAC output stage is disconnected from the amplifier and - 1kohm_to_gnd: connected to ground via an 1kOhm resistor, + 1kohm_to_gnd: connected to ground via an 1kOhm resistor, 6kohm_to_gnd: connected to ground via a 6kOhm resistor, 20kohm_to_gnd: connected to ground via a 20kOhm resistor, 100kohm_to_gnd: connected to ground via an 100kOhm resistor, @@ -498,9 +503,9 @@ Description: outX_powerdown_mode_available. If Y is not present the mode is shared across all outputs. -What: /sys/.../iio:deviceX/out_votlageY_powerdown_mode_available +What: /sys/.../iio:deviceX/out_voltageY_powerdown_mode_available What: /sys/.../iio:deviceX/out_voltage_powerdown_mode_available -What: /sys/.../iio:deviceX/out_altvotlageY_powerdown_mode_available +What: /sys/.../iio:deviceX/out_altvoltageY_powerdown_mode_available What: /sys/.../iio:deviceX/out_altvoltage_powerdown_mode_available KernelVersion: 2.6.38 Contact: linux-iio@vger.kernel.org @@ -1035,13 +1040,6 @@ Contact: linux-iio@vger.kernel.org Description: Number of scans contained by the buffer. -What: /sys/bus/iio/devices/iio:deviceX/buffer/bytes_per_datum -KernelVersion: 2.6.37 -Contact: linux-iio@vger.kernel.org -Description: - Bytes per scan. Due to alignment fun, the scan may be larger - than implied directly by the scan_element parameters. - What: /sys/bus/iio/devices/iio:deviceX/buffer/enable KernelVersion: 2.6.35 Contact: linux-iio@vger.kernel.org diff --git a/Documentation/ABI/testing/sysfs-bus-iio-trigger-sysfs b/Documentation/ABI/testing/sysfs-bus-iio-trigger-sysfs index 5235e6c749ab..bbb039237a25 100644 --- a/Documentation/ABI/testing/sysfs-bus-iio-trigger-sysfs +++ b/Documentation/ABI/testing/sysfs-bus-iio-trigger-sysfs @@ -9,3 +9,12 @@ Description: 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. + +What: /sys/bus/iio/devices/triggerX/name +KernelVersion: 2.6.39 +Contact: linux-iio@vger.kernel.org +Description: + The name attribute holds a description string for the current + trigger. In order to associate the trigger with an IIO device + one should write this name string to + /sys/bus/iio/devices/iio:deviceY/trigger/current_trigger. diff --git a/Documentation/DocBook/Makefile b/Documentation/DocBook/Makefile index b6a6a2e0dd3b..9e086067b4ae 100644 --- a/Documentation/DocBook/Makefile +++ b/Documentation/DocBook/Makefile @@ -15,7 +15,7 @@ DOCBOOKS := z8530book.xml device-drivers.xml \ 80211.xml debugobjects.xml sh.xml regulator.xml \ alsa-driver-api.xml writing-an-alsa-driver.xml \ tracepoint.xml drm.xml media_api.xml w1.xml \ - writing_musb_glue_layer.xml crypto-API.xml + writing_musb_glue_layer.xml crypto-API.xml iio.xml include Documentation/DocBook/media/Makefile diff --git a/Documentation/DocBook/iio.tmpl b/Documentation/DocBook/iio.tmpl new file mode 100644 index 000000000000..06bb53de5a47 --- /dev/null +++ b/Documentation/DocBook/iio.tmpl @@ -0,0 +1,697 @@ +<?xml version="1.0" encoding="UTF-8"?> +<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN" + "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" []> + +<book id="iioid"> + <bookinfo> + <title>Industrial I/O driver developer's guide </title> + + <authorgroup> + <author> + <firstname>Daniel</firstname> + <surname>Baluta</surname> + <affiliation> + <address> + <email>daniel.baluta@intel.com</email> + </address> + </affiliation> + </author> + </authorgroup> + + <copyright> + <year>2015</year> + <holder>Intel Corporation</holder> + </copyright> + + <legalnotice> + <para> + This documentation is free software; you can redistribute + it and/or modify it under the terms of the GNU General Public + License version 2. + </para> + </legalnotice> + </bookinfo> + + <toc></toc> + + <chapter id="intro"> + <title>Introduction</title> + <para> + The main purpose of the Industrial I/O subsystem (IIO) is to provide + support for devices that in some sense perform either analog-to-digital + conversion (ADC) or digital-to-analog conversion (DAC) or both. The aim + is to fill the gap between the somewhat similar hwmon and input + subsystems. + Hwmon is directed at low sample rate sensors used to monitor and + control the system itself, like fan speed control or temperature + measurement. Input is, as its name suggests, focused on human interaction + input devices (keyboard, mouse, touchscreen). In some cases there is + considerable overlap between these and IIO. + </para> + <para> + Devices that fall into this category include: + <itemizedlist> + <listitem> + analog to digital converters (ADCs) + </listitem> + <listitem> + accelerometers + </listitem> + <listitem> + capacitance to digital converters (CDCs) + </listitem> + <listitem> + digital to analog converters (DACs) + </listitem> + <listitem> + gyroscopes + </listitem> + <listitem> + inertial measurement units (IMUs) + </listitem> + <listitem> + color and light sensors + </listitem> + <listitem> + magnetometers + </listitem> + <listitem> + pressure sensors + </listitem> + <listitem> + proximity sensors + </listitem> + <listitem> + temperature sensors + </listitem> + </itemizedlist> + Usually these sensors are connected via SPI or I2C. A common use case of the + sensors devices is to have combined functionality (e.g. light plus proximity + sensor). + </para> + </chapter> + <chapter id='iiosubsys'> + <title>Industrial I/O core</title> + <para> + The Industrial I/O core offers: + <itemizedlist> + <listitem> + a unified framework for writing drivers for many different types of + embedded sensors. + </listitem> + <listitem> + a standard interface to user space applications manipulating sensors. + </listitem> + </itemizedlist> + The implementation can be found under <filename> + drivers/iio/industrialio-*</filename> + </para> + <sect1 id="iiodevice"> + <title> Industrial I/O devices </title> + +!Finclude/linux/iio/iio.h iio_dev +!Fdrivers/iio/industrialio-core.c iio_device_alloc +!Fdrivers/iio/industrialio-core.c iio_device_free +!Fdrivers/iio/industrialio-core.c iio_device_register +!Fdrivers/iio/industrialio-core.c iio_device_unregister + + <para> + An IIO device usually corresponds to a single hardware sensor and it + provides all the information needed by a driver handling a device. + Let's first have a look at the functionality embedded in an IIO + device then we will show how a device driver makes use of an IIO + device. + </para> + <para> + There are two ways for a user space application to interact + with an IIO driver. + <itemizedlist> + <listitem> + <filename>/sys/bus/iio/iio:deviceX/</filename>, this + represents a hardware sensor and groups together the data + channels of the same chip. + </listitem> + <listitem> + <filename>/dev/iio:deviceX</filename>, character device node + interface used for buffered data transfer and for events information + retrieval. + </listitem> + </itemizedlist> + </para> + A typical IIO driver will register itself as an I2C or SPI driver and will + create two routines, <function> probe </function> and <function> remove + </function>. At <function>probe</function>: + <itemizedlist> + <listitem>call <function>iio_device_alloc</function>, which allocates memory + for an IIO device. + </listitem> + <listitem> initialize IIO device fields with driver specific information + (e.g. device name, device channels). + </listitem> + <listitem>call <function> iio_device_register</function>, this registers the + device with the IIO core. After this call the device is ready to accept + requests from user space applications. + </listitem> + </itemizedlist> + At <function>remove</function>, we free the resources allocated in + <function>probe</function> in reverse order: + <itemizedlist> + <listitem><function>iio_device_unregister</function>, unregister the device + from the IIO core. + </listitem> + <listitem><function>iio_device_free</function>, free the memory allocated + for the IIO device. + </listitem> + </itemizedlist> + + <sect2 id="iioattr"> <title> IIO device sysfs interface </title> + <para> + Attributes are sysfs files used to expose chip info and also allowing + applications to set various configuration parameters. For device + with index X, attributes can be found under + <filename>/sys/bus/iio/iio:deviceX/ </filename> directory. + Common attributes are: + <itemizedlist> + <listitem><filename>name</filename>, description of the physical + chip. + </listitem> + <listitem><filename>dev</filename>, shows the major:minor pair + associated with <filename>/dev/iio:deviceX</filename> node. + </listitem> + <listitem><filename>sampling_frequency_available</filename>, + available discrete set of sampling frequency values for + device. + </listitem> + </itemizedlist> + Available standard attributes for IIO devices are described in the + <filename>Documentation/ABI/testing/sysfs-bus-iio </filename> file + in the Linux kernel sources. + </para> + </sect2> + <sect2 id="iiochannel"> <title> IIO device channels </title> +!Finclude/linux/iio/iio.h iio_chan_spec structure. + <para> + An IIO device channel is a representation of a data channel. An + IIO device can have one or multiple channels. For example: + <itemizedlist> + <listitem> + a thermometer sensor has one channel representing the + temperature measurement. + </listitem> + <listitem> + a light sensor with two channels indicating the measurements in + the visible and infrared spectrum. + </listitem> + <listitem> + an accelerometer can have up to 3 channels representing + acceleration on X, Y and Z axes. + </listitem> + </itemizedlist> + An IIO channel is described by the <type> struct iio_chan_spec + </type>. A thermometer driver for the temperature sensor in the + example above would have to describe its channel as follows: + <programlisting> + static const struct iio_chan_spec temp_channel[] = { + { + .type = IIO_TEMP, + .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), + }, + }; + + </programlisting> + Channel sysfs attributes exposed to userspace are specified in + the form of <emphasis>bitmasks</emphasis>. Depending on their + shared info, attributes can be set in one of the following masks: + <itemizedlist> + <listitem><emphasis>info_mask_separate</emphasis>, attributes will + be specific to this channel</listitem> + <listitem><emphasis>info_mask_shared_by_type</emphasis>, + attributes are shared by all channels of the same type</listitem> + <listitem><emphasis>info_mask_shared_by_dir</emphasis>, attributes + are shared by all channels of the same direction </listitem> + <listitem><emphasis>info_mask_shared_by_all</emphasis>, + attributes are shared by all channels</listitem> + </itemizedlist> + When there are multiple data channels per channel type we have two + ways to distinguish between them: + <itemizedlist> + <listitem> set <emphasis> .modified</emphasis> field of <type> + iio_chan_spec</type> to 1. Modifiers are specified using + <emphasis>.channel2</emphasis> field of the same + <type>iio_chan_spec</type> structure and are used to indicate a + physically unique characteristic of the channel such as its direction + or spectral response. For example, a light sensor can have two channels, + one for infrared light and one for both infrared and visible light. + </listitem> + <listitem> set <emphasis>.indexed </emphasis> field of + <type>iio_chan_spec</type> to 1. In this case the channel is + simply another instance with an index specified by the + <emphasis>.channel</emphasis> field. + </listitem> + </itemizedlist> + Here is how we can make use of the channel's modifiers: + <programlisting> + static const struct iio_chan_spec light_channels[] = { + { + .type = IIO_INTENSITY, + .modified = 1, + .channel2 = IIO_MOD_LIGHT_IR, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), + .info_mask_shared = BIT(IIO_CHAN_INFO_SAMP_FREQ), + }, + { + .type = IIO_INTENSITY, + .modified = 1, + .channel2 = IIO_MOD_LIGHT_BOTH, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), + .info_mask_shared = BIT(IIO_CHAN_INFO_SAMP_FREQ), + }, + { + .type = IIO_LIGHT, + .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), + .info_mask_shared = BIT(IIO_CHAN_INFO_SAMP_FREQ), + }, + + } + </programlisting> + This channel's definition will generate two separate sysfs files + for raw data retrieval: + <itemizedlist> + <listitem> + <filename>/sys/bus/iio/iio:deviceX/in_intensity_ir_raw</filename> + </listitem> + <listitem> + <filename>/sys/bus/iio/iio:deviceX/in_intensity_both_raw</filename> + </listitem> + </itemizedlist> + one file for processed data: + <itemizedlist> + <listitem> + <filename>/sys/bus/iio/iio:deviceX/in_illuminance_input + </filename> + </listitem> + </itemizedlist> + and one shared sysfs file for sampling frequency: + <itemizedlist> + <listitem> + <filename>/sys/bus/iio/iio:deviceX/sampling_frequency. + </filename> + </listitem> + </itemizedlist> + </para> + <para> + Here is how we can make use of the channel's indexing: + <programlisting> + static const struct iio_chan_spec light_channels[] = { + { + .type = IIO_VOLTAGE, + .indexed = 1, + .channel = 0, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), + }, + { + .type = IIO_VOLTAGE, + .indexed = 1, + .channel = 1, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), + }, + } + </programlisting> + This will generate two separate attributes files for raw data + retrieval: + <itemizedlist> + <listitem> + <filename>/sys/bus/iio/devices/iio:deviceX/in_voltage0_raw</filename>, + representing voltage measurement for channel 0. + </listitem> + <listitem> + <filename>/sys/bus/iio/devices/iio:deviceX/in_voltage1_raw</filename>, + representing voltage measurement for channel 1. + </listitem> + </itemizedlist> + </para> + </sect2> + </sect1> + + <sect1 id="iiobuffer"> <title> Industrial I/O buffers </title> +!Finclude/linux/iio/buffer.h iio_buffer +!Edrivers/iio/industrialio-buffer.c + + <para> + The Industrial I/O core offers a way for continuous data capture + based on a trigger source. Multiple data channels can be read at once + from <filename>/dev/iio:deviceX</filename> character device node, + thus reducing the CPU load. + </para> + + <sect2 id="iiobuffersysfs"> + <title>IIO buffer sysfs interface </title> + <para> + An IIO buffer has an associated attributes directory under <filename> + /sys/bus/iio/iio:deviceX/buffer/</filename>. Here are the existing + attributes: + <itemizedlist> + <listitem> + <emphasis>length</emphasis>, the total number of data samples + (capacity) that can be stored by the buffer. + </listitem> + <listitem> + <emphasis>enable</emphasis>, activate buffer capture. + </listitem> + </itemizedlist> + + </para> + </sect2> + <sect2 id="iiobuffersetup"> <title> IIO buffer setup </title> + <para>The meta information associated with a channel reading + placed in a buffer is called a <emphasis> scan element </emphasis>. + The important bits configuring scan elements are exposed to + userspace applications via the <filename> + /sys/bus/iio/iio:deviceX/scan_elements/</filename> directory. This + file contains attributes of the following form: + <itemizedlist> + <listitem><emphasis>enable</emphasis>, used for enabling a channel. + If and only if its attribute is non zero, then a triggered capture + will contain data samples for this channel. + </listitem> + <listitem><emphasis>type</emphasis>, description of the scan element + data storage within the buffer and hence the form in which it is + read from user space. Format is <emphasis> + [be|le]:[s|u]bits/storagebitsXrepeat[>>shift] </emphasis>. + <itemizedlist> + <listitem> <emphasis>be</emphasis> or <emphasis>le</emphasis>, specifies + big or little endian. + </listitem> + <listitem> + <emphasis>s </emphasis>or <emphasis>u</emphasis>, specifies if + signed (2's complement) or unsigned. + </listitem> + <listitem><emphasis>bits</emphasis>, is the number of valid data + bits. + </listitem> + <listitem><emphasis>storagebits</emphasis>, is the number of bits + (after padding) that it occupies in the buffer. + </listitem> + <listitem> + <emphasis>shift</emphasis>, if specified, is the shift that needs + to be applied prior to masking out unused bits. + </listitem> + <listitem> + <emphasis>repeat</emphasis>, specifies the number of bits/storagebits + repetitions. When the repeat element is 0 or 1, then the repeat + value is omitted. + </listitem> + </itemizedlist> + </listitem> + </itemizedlist> + For example, a driver for a 3-axis accelerometer with 12 bit + resolution where data is stored in two 8-bits registers as + follows: + <programlisting> + 7 6 5 4 3 2 1 0 + +---+---+---+---+---+---+---+---+ + |D3 |D2 |D1 |D0 | X | X | X | X | (LOW byte, address 0x06) + +---+---+---+---+---+---+---+---+ + + 7 6 5 4 3 2 1 0 + +---+---+---+---+---+---+---+---+ + |D11|D10|D9 |D8 |D7 |D6 |D5 |D4 | (HIGH byte, address 0x07) + +---+---+---+---+---+---+---+---+ + </programlisting> + + will have the following scan element type for each axis: + <programlisting> + $ cat /sys/bus/iio/devices/iio:device0/scan_elements/in_accel_y_type + le:s12/16>>4 + </programlisting> + A user space application will interpret data samples read from the + buffer as two byte little endian signed data, that needs a 4 bits + right shift before masking out the 12 valid bits of data. + </para> + <para> + For implementing buffer support a driver should initialize the following + fields in <type>iio_chan_spec</type> definition: + <programlisting> + struct iio_chan_spec { + /* other members */ + int scan_index + struct { + char sign; + u8 realbits; + u8 storagebits; + u8 shift; + u8 repeat; + enum iio_endian endianness; + } scan_type; + }; + </programlisting> + The driver implementing the accelerometer described above will + have the following channel definition: + <programlisting> + struct struct iio_chan_spec accel_channels[] = { + { + .type = IIO_ACCEL, + .modified = 1, + .channel2 = IIO_MOD_X, + /* other stuff here */ + .scan_index = 0, + .scan_type = { + .sign = 's', + .realbits = 12, + .storgebits = 16, + .shift = 4, + .endianness = IIO_LE, + }, + } + /* similar for Y (with channel2 = IIO_MOD_Y, scan_index = 1) + * and Z (with channel2 = IIO_MOD_Z, scan_index = 2) axis + */ + } + </programlisting> + </para> + <para> + Here <emphasis> scan_index </emphasis> defines the order in which + the enabled channels are placed inside the buffer. Channels with a lower + scan_index will be placed before channels with a higher index. Each + channel needs to have a unique scan_index. + </para> + <para> + Setting scan_index to -1 can be used to indicate that the specific + channel does not support buffered capture. In this case no entries will + be created for the channel in the scan_elements directory. + </para> + </sect2> + </sect1> + + <sect1 id="iiotrigger"> <title> Industrial I/O triggers </title> +!Finclude/linux/iio/trigger.h iio_trigger +!Edrivers/iio/industrialio-trigger.c + <para> + In many situations it is useful for a driver to be able to + capture data based on some external event (trigger) as opposed + to periodically polling for data. An IIO trigger can be provided + by a device driver that also has an IIO device based on hardware + generated events (e.g. data ready or threshold exceeded) or + provided by a separate driver from an independent interrupt + source (e.g. GPIO line connected to some external system, timer + interrupt or user space writing a specific file in sysfs). A + trigger may initiate data capture for a number of sensors and + also it may be completely unrelated to the sensor itself. + </para> + + <sect2 id="iiotrigsysfs"> <title> IIO trigger sysfs interface </title> + There are two locations in sysfs related to triggers: + <itemizedlist> + <listitem><filename>/sys/bus/iio/devices/triggerY</filename>, + this file is created once an IIO trigger is registered with + the IIO core and corresponds to trigger with index Y. Because + triggers can be very different depending on type there are few + standard attributes that we can describe here: + <itemizedlist> + <listitem> + <emphasis>name</emphasis>, trigger name that can be later + used for association with a device. + </listitem> + <listitem> + <emphasis>sampling_frequency</emphasis>, some timer based + triggers use this attribute to specify the frequency for + trigger calls. + </listitem> + </itemizedlist> + </listitem> + <listitem> + <filename>/sys/bus/iio/devices/iio:deviceX/trigger/</filename>, this + directory is created once the device supports a triggered + buffer. We can associate a trigger with our device by writing + the trigger's name in the <filename>current_trigger</filename> file. + </listitem> + </itemizedlist> + </sect2> + + <sect2 id="iiotrigattr"> <title> IIO trigger setup</title> + + <para> + Let's see a simple example of how to setup a trigger to be used + by a driver. + + <programlisting> + struct iio_trigger_ops trigger_ops = { + .set_trigger_state = sample_trigger_state, + .validate_device = sample_validate_device, + } + + struct iio_trigger *trig; + + /* first, allocate memory for our trigger */ + trig = iio_trigger_alloc(dev, "trig-%s-%d", name, idx); + + /* setup trigger operations field */ + trig->ops = &trigger_ops; + + /* now register the trigger with the IIO core */ + iio_trigger_register(trig); + </programlisting> + </para> + </sect2> + + <sect2 id="iiotrigsetup"> <title> IIO trigger ops</title> +!Finclude/linux/iio/trigger.h iio_trigger_ops + <para> + Notice that a trigger has a set of operations attached: + <itemizedlist> + <listitem> + <function>set_trigger_state</function>, switch the trigger on/off + on demand. + </listitem> + <listitem> + <function>validate_device</function>, function to validate the + device when the current trigger gets changed. + </listitem> + </itemizedlist> + </para> + </sect2> + </sect1> + <sect1 id="iiotriggered_buffer"> + <title> Industrial I/O triggered buffers </title> + <para> + Now that we know what buffers and triggers are let's see how they + work together. + </para> + <sect2 id="iiotrigbufsetup"> <title> IIO triggered buffer setup</title> +!Edrivers/iio/industrialio-triggered-buffer.c +!Finclude/linux/iio/iio.h iio_buffer_setup_ops + + + <para> + A typical triggered buffer setup looks like this: + <programlisting> + const struct iio_buffer_setup_ops sensor_buffer_setup_ops = { + .preenable = sensor_buffer_preenable, + .postenable = sensor_buffer_postenable, + .postdisable = sensor_buffer_postdisable, + .predisable = sensor_buffer_predisable, + }; + + irqreturn_t sensor_iio_pollfunc(int irq, void *p) + { + pf->timestamp = iio_get_time_ns(); + return IRQ_WAKE_THREAD; + } + + irqreturn_t sensor_trigger_handler(int irq, void *p) + { + u16 buf[8]; + int i = 0; + + /* read data for each active channel */ + for_each_set_bit(bit, active_scan_mask, masklength) + buf[i++] = sensor_get_data(bit) + + iio_push_to_buffers_with_timestamp(indio_dev, buf, timestamp); + + iio_trigger_notify_done(trigger); + return IRQ_HANDLED; + } + + /* setup triggered buffer, usually in probe function */ + iio_triggered_buffer_setup(indio_dev, sensor_iio_polfunc, + sensor_trigger_handler, + sensor_buffer_setup_ops); + </programlisting> + </para> + The important things to notice here are: + <itemizedlist> + <listitem><function> iio_buffer_setup_ops</function>, the buffer setup + functions to be called at predefined points in the buffer configuration + sequence (e.g. before enable, after disable). If not specified, the + IIO core uses the default <type>iio_triggered_buffer_setup_ops</type>. + </listitem> + <listitem><function>sensor_iio_pollfunc</function>, the function that + will be used as top half of poll function. It should do as little + processing as possible, because it runs in interrupt context. The most + common operation is recording of the current timestamp and for this reason + one can use the IIO core defined <function>iio_pollfunc_store_time + </function> function. + </listitem> + <listitem><function>sensor_trigger_handler</function>, the function that + will be used as bottom half of the poll function. This runs in the + context of a kernel thread and all the processing takes place here. + It usually reads data from the device and stores it in the internal + buffer together with the timestamp recorded in the top half. + </listitem> + </itemizedlist> + </sect2> + </sect1> + </chapter> + <chapter id='iioresources'> + <title> Resources </title> + IIO core may change during time so the best documentation to read is the + source code. There are several locations where you should look: + <itemizedlist> + <listitem> + <filename>drivers/iio/</filename>, contains the IIO core plus + and directories for each sensor type (e.g. accel, magnetometer, + etc.) + </listitem> + <listitem> + <filename>include/linux/iio/</filename>, contains the header + files, nice to read for the internal kernel interfaces. + </listitem> + <listitem> + <filename>include/uapi/linux/iio/</filename>, contains files to be + used by user space applications. + </listitem> + <listitem> + <filename>tools/iio/</filename>, contains tools for rapidly + testing buffers, events and device creation. + </listitem> + <listitem> + <filename>drivers/staging/iio/</filename>, contains code for some + drivers or experimental features that are not yet mature enough + to be moved out. + </listitem> + </itemizedlist> + <para> + Besides the code, there are some good online documentation sources: + <itemizedlist> + <listitem> + <ulink url="http://marc.info/?l=linux-iio"> Industrial I/O mailing + list </ulink> + </listitem> + <listitem> + <ulink url="http://wiki.analog.com/software/linux/docs/iio/iio"> + Analog Device IIO wiki page </ulink> + </listitem> + <listitem> + <ulink url="https://fosdem.org/2015/schedule/event/iiosdr/"> + Using the Linux IIO framework for SDR, Lars-Peter Clausen's + presentation at FOSDEM </ulink> + </listitem> + </itemizedlist> + </para> + </chapter> +</book> + +<!-- +vim: softtabstop=2:shiftwidth=2:expandtab:textwidth=72 +--> diff --git a/Documentation/devicetree/bindings/iio/adc/mcp320x.txt b/Documentation/devicetree/bindings/iio/adc/mcp320x.txt index b85184391b78..2a1f3af30155 100644 --- a/Documentation/devicetree/bindings/iio/adc/mcp320x.txt +++ b/Documentation/devicetree/bindings/iio/adc/mcp320x.txt @@ -18,6 +18,7 @@ Required properties: "mcp3202" "mcp3204" "mcp3208" + "mcp3301" Examples: diff --git a/Documentation/devicetree/bindings/iio/adc/vf610-adc.txt b/Documentation/devicetree/bindings/iio/adc/vf610-adc.txt index 3eb40e20c143..1aad0514e647 100644 --- a/Documentation/devicetree/bindings/iio/adc/vf610-adc.txt +++ b/Documentation/devicetree/bindings/iio/adc/vf610-adc.txt @@ -17,6 +17,11 @@ Recommended properties: - Frequency in normal mode (ADLPC=0, ADHSC=0) - Frequency in high-speed mode (ADLPC=0, ADHSC=1) - Frequency in low-power mode (ADLPC=1, ADHSC=0) +- min-sample-time: Minimum sampling time in nanoseconds. This value has + to be chosen according to the conversion mode and the connected analog + source resistance (R_as) and capacitance (C_as). Refer the datasheet's + operating requirements. A safe default across a wide range of R_as and + C_as as well as conversion modes is 1000ns. Example: adc0: adc@4003b000 { diff --git a/Documentation/devicetree/bindings/iio/magnetometer/mmc35240.txt b/Documentation/devicetree/bindings/iio/magnetometer/mmc35240.txt new file mode 100644 index 000000000000..a01235c7fa15 --- /dev/null +++ b/Documentation/devicetree/bindings/iio/magnetometer/mmc35240.txt @@ -0,0 +1,13 @@ +* MEMSIC MMC35240 magnetometer sensor + +Required properties: + + - compatible : should be "memsic,mmc35240" + - reg : the I2C address of the magnetometer + +Example: + +mmc35240@30 { + compatible = "memsic,mmc35240"; + reg = <0x30>; +}; diff --git a/Documentation/devicetree/bindings/iio/st-sensors.txt b/Documentation/devicetree/bindings/iio/st-sensors.txt index 8a6be3bdf267..d3ccdb190c53 100644 --- a/Documentation/devicetree/bindings/iio/st-sensors.txt +++ b/Documentation/devicetree/bindings/iio/st-sensors.txt @@ -35,6 +35,7 @@ Accelerometers: - st,lsm303dl-accel - st,lsm303dlm-accel - st,lsm330-accel +- st,lsm303agr-accel Gyroscopes: - st,l3g4200d-gyro @@ -46,6 +47,7 @@ Gyroscopes: - st,lsm330-gyro Magnetometers: +- st,lsm303agr-magn - st,lsm303dlh-magn - st,lsm303dlhc-magn - st,lsm303dlm-magn diff --git a/Documentation/devicetree/bindings/staging/iio/adc/mxs-lradc.txt b/Documentation/devicetree/bindings/staging/iio/adc/mxs-lradc.txt index 307537787574..555fb117d4fa 100644 --- a/Documentation/devicetree/bindings/staging/iio/adc/mxs-lradc.txt +++ b/Documentation/devicetree/bindings/staging/iio/adc/mxs-lradc.txt @@ -1,4 +1,4 @@ -* Freescale i.MX28 LRADC device driver +* Freescale MXS LRADC device driver Required properties: - compatible: Should be "fsl,imx23-lradc" for i.MX23 SoC and "fsl,imx28-lradc" diff --git a/Documentation/fb/sm712fb.txt b/Documentation/fb/sm712fb.txt new file mode 100644 index 000000000000..c388442edf51 --- /dev/null +++ b/Documentation/fb/sm712fb.txt @@ -0,0 +1,31 @@ +What is sm712fb? +================= + +This is a graphics framebuffer driver for Silicon Motion SM712 based processors. + +How to use it? +============== + +Switching modes is done using the video=sm712fb:... boot parameter. + +If you want, for example, enable a resolution of 1280x1024x24bpp you should +pass to the kernel this command line: "video=sm712fb:0x31B". + +You should not compile-in vesafb. + +Currently supported video modes are: + +[Graphic modes] + +bpp | 640x480 800x600 1024x768 1280x1024 +----+-------------------------------------------- + 8 | 0x301 0x303 0x305 0x307 + 16 | 0x311 0x314 0x317 0x31A + 24 | 0x312 0x315 0x318 0x31B + +Missing Features +================ +(alias TODO list) + + * 2D acceleratrion + * dual-head support |