€•kÖŒsphinx.addnodes”Œdocument”“”)”}”(Œ rawsource”Œ”Œchildren”]”(Œtranslations”Œ LanguagesNode”“”)”}”(hhh]”(hŒpending_xref”“”)”}”(hhh]”Œdocutils.nodes”ŒText”“”ŒChinese (Simplified)”…””}”Œparent”hsbaŒ attributes”}”(Œids”]”Œclasses”]”Œnames”]”Œdupnames”]”Œbackrefs”]”Œ refdomain”Œstd”Œreftype”Œdoc”Œ reftarget”Œ#/translations/zh_CN/leds/leds-class”Œmodname”NŒ classname”NŒrefexplicit”ˆuŒtagname”hhhubh)”}”(hhh]”hŒChinese (Traditional)”…””}”hh2sbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ#/translations/zh_TW/leds/leds-class”Œmodname”NŒ classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒItalian”…””}”hhFsbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ#/translations/it_IT/leds/leds-class”Œmodname”NŒ classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒJapanese”…””}”hhZsbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ#/translations/ja_JP/leds/leds-class”Œmodname”NŒ classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒKorean”…””}”hhnsbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ#/translations/ko_KR/leds/leds-class”Œmodname”NŒ classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒPortuguese (Brazilian)”…””}”hh‚sbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ#/translations/pt_BR/leds/leds-class”Œmodname”NŒ classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒSpanish”…””}”hh–sbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ#/translations/sp_SP/leds/leds-class”Œmodname”NŒ classname”NŒrefexplicit”ˆuh1hhhubeh}”(h]”h ]”h"]”h$]”h&]”Œcurrent_language”ŒEnglish”uh1h hhŒ _document”hŒsource”NŒline”NubhŒsection”“”)”}”(hhh]”(hŒtitle”“”)”}”(hŒLED handling under Linux”h]”hŒLED handling under Linux”…””}”(hh¼h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hºhh·h²hh³Œ=/var/lib/git/docbuild/linux/Documentation/leds/leds-class.rst”h´KubhŒ paragraph”“”)”}”(hX|In its simplest form, the LED class just allows control of LEDs from userspace. LEDs appear in /sys/class/leds/. The maximum brightness of the LED is defined in max_brightness file. The brightness file will set the brightness of the LED (taking a value 0-max_brightness). Most LEDs don't have hardware brightness support so will just be turned on for non-zero brightness settings.”h]”hX~In its simplest form, the LED class just allows control of LEDs from userspace. LEDs appear in /sys/class/leds/. The maximum brightness of the LED is defined in max_brightness file. The brightness file will set the brightness of the LED (taking a value 0-max_brightness). Most LEDs donâ€™t have hardware brightness support so will just be turned on for non-zero brightness settings.”…””}”(hhÍh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´Khh·h²hubhÌ)”}”(hXŒThe class also introduces the optional concept of an LED trigger. A trigger is a kernel based source of led events. Triggers can either be simple or complex. A simple trigger isn't configurable and is designed to slot into existing subsystems with minimal additional code. Examples are the disk-activity, nand-disk and sharpsl-charge triggers. With led triggers disabled, the code optimises away.”h]”hXŽThe class also introduces the optional concept of an LED trigger. A trigger is a kernel based source of led events. Triggers can either be simple or complex. A simple trigger isnâ€™t configurable and is designed to slot into existing subsystems with minimal additional code. Examples are the disk-activity, nand-disk and sharpsl-charge triggers. With led triggers disabled, the code optimises away.”…””}”(hhÛh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´Khh·h²hubhÌ)”}”(hXComplex triggers while available to all LEDs have LED specific parameters and work on a per LED basis. The timer trigger is an example. The timer trigger will periodically change the LED brightness between LED_OFF and the current brightness setting. The "on" and "off" time can be specified via /sys/class/leds//delay_{on,off} in milliseconds. You can change the brightness value of a LED independently of the timer trigger. However, if you set the brightness value to LED_OFF it will also disable the timer trigger.”h]”hXComplex triggers while available to all LEDs have LED specific parameters and work on a per LED basis. The timer trigger is an example. The timer trigger will periodically change the LED brightness between LED_OFF and the current brightness setting. The â€œonâ€ and â€œoffâ€ time can be specified via /sys/class/leds//delay_{on,off} in milliseconds. You can change the brightness value of a LED independently of the timer trigger. However, if you set the brightness value to LED_OFF it will also disable the timer trigger.”…””}”(hhéh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´Khh·h²hubhÌ)”}”(hŒÝYou can change triggers in a similar manner to the way an IO scheduler is chosen (via /sys/class/leds//trigger). Trigger specific parameters can appear in /sys/class/leds/ once a given trigger is selected.”h]”hŒÝYou can change triggers in a similar manner to the way an IO scheduler is chosen (via /sys/class/leds//trigger). Trigger specific parameters can appear in /sys/class/leds/ once a given trigger is selected.”…””}”(hh÷h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´Khh·h²hubh¶)”}”(hhh]”(h»)”}”(hŒDesign Philosophy”h]”hŒDesign Philosophy”…””}”(hjh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hºhjh²hh³hÊh´K"ubhÌ)”}”(hŒ×The underlying design philosophy is simplicity. LEDs are simple devices and the aim is to keep a small amount of code giving as much functionality as possible. Please keep this in mind when suggesting enhancements.”h]”hŒ×The underlying design philosophy is simplicity. LEDs are simple devices and the aim is to keep a small amount of code giving as much functionality as possible. Please keep this in mind when suggesting enhancements.”…””}”(hjh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´K$hjh²hubeh}”(h]”Œdesign-philosophy”ah ]”h"]”Œdesign philosophy”ah$]”h&]”uh1hµhh·h²hh³hÊh´K"ubh¶)”}”(hhh]”(h»)”}”(hŒLED Device Naming”h]”hŒLED Device Naming”…””}”(hj/h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hºhj,h²hh³hÊh´K*ubhÌ)”}”(hŒIs currently of the form:”h]”hŒIs currently of the form:”…””}”(hj=h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´K,hj,h²hubhŒblock_quote”“”)”}”(hŒ"devicename:color:function" ”h]”hÌ)”}”(hŒ"devicename:color:function"”h]”hŒâ€œdevicename:color:functionâ€”…””}”(hjQh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´K.hjMubah}”(h]”h ]”h"]”h$]”h&]”uh1jKh³hÊh´K.hj,h²hubhŒbullet_list”“”)”}”(hhh]”(hŒ list_item”“”)”}”(hXçdevicename: it should refer to a unique identifier created by the kernel, like e.g. phyN for network devices or inputN for input devices, rather than to the hardware; the information related to the product and the bus to which given device is hooked is available in sysfs and can be retrieved using get_led_device_info.sh script from tools/leds; generally this section is expected mostly for LEDs that are somehow associated with other devices. ”h]”hŒdefinition_list”“”)”}”(hhh]”hŒdefinition_list_item”“”)”}”(hX½devicename: it should refer to a unique identifier created by the kernel, like e.g. phyN for network devices or inputN for input devices, rather than to the hardware; the information related to the product and the bus to which given device is hooked is available in sysfs and can be retrieved using get_led_device_info.sh script from tools/leds; generally this section is expected mostly for LEDs that are somehow associated with other devices. ”h]”(hŒterm”“”)”}”(hŒdevicename:”h]”hŒdevicename:”…””}”(hj}h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j{h³hÊh´K7hjwubhŒ definition”“”)”}”(hhh]”hÌ)”}”(hX°it should refer to a unique identifier created by the kernel, like e.g. phyN for network devices or inputN for input devices, rather than to the hardware; the information related to the product and the bus to which given device is hooked is available in sysfs and can be retrieved using get_led_device_info.sh script from tools/leds; generally this section is expected mostly for LEDs that are somehow associated with other devices.”h]”hX°it should refer to a unique identifier created by the kernel, like e.g. phyN for network devices or inputN for input devices, rather than to the hardware; the information related to the product and the bus to which given device is hooked is available in sysfs and can be retrieved using get_led_device_info.sh script from tools/leds; generally this section is expected mostly for LEDs that are somehow associated with other devices.”…””}”(hjh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´K1hjubah}”(h]”h ]”h"]”h$]”h&]”uh1j‹hjwubeh}”(h]”h ]”h"]”h$]”h&]”uh1juh³hÊh´K7hjrubah}”(h]”h ]”h"]”h$]”h&]”uh1jphjlubah}”(h]”h ]”h"]”h$]”h&]”uh1jjhjgh²hh³Nh´Nubjk)”}”(hŒhcolor: one of LED_COLOR_ID_* definitions from the header include/dt-bindings/leds/common.h. ”h]”jq)”}”(hhh]”jv)”}”(hŒ\color: one of LED_COLOR_ID_* definitions from the header include/dt-bindings/leds/common.h. ”h]”(j|)”}”(hŒcolor:”h]”hŒcolor:”…””}”(hjÁh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j{h³hÊh´K;hj½ubjŒ)”}”(hhh]”hÌ)”}”(hŒTone of LED_COLOR_ID_* definitions from the header include/dt-bindings/leds/common.h.”h]”hŒTone of LED_COLOR_ID_* definitions from the header include/dt-bindings/leds/common.h.”…””}”(hjÒh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´K:hjÏubah}”(h]”h ]”h"]”h$]”h&]”uh1j‹hj½ubeh}”(h]”h ]”h"]”h$]”h&]”uh1juh³hÊh´K;hjºubah}”(h]”h ]”h"]”h$]”h&]”uh1jphj¶ubah}”(h]”h ]”h"]”h$]”h&]”uh1jjhjgh²hh³Nh´Nubjk)”}”(hŒkfunction: one of LED_FUNCTION_* definitions from the header include/dt-bindings/leds/common.h. ”h]”jq)”}”(hhh]”jv)”}”(hŒ_function: one of LED_FUNCTION_* definitions from the header include/dt-bindings/leds/common.h. ”h]”(j|)”}”(hŒ function:”h]”hŒ function:”…””}”(hjh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j{h³hÊh´K?hjÿubjŒ)”}”(hhh]”hÌ)”}”(hŒTone of LED_FUNCTION_* definitions from the header include/dt-bindings/leds/common.h.”h]”hŒTone of LED_FUNCTION_* definitions from the header include/dt-bindings/leds/common.h.”…””}”(hjh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´K>hjubah}”(h]”h ]”h"]”h$]”h&]”uh1j‹hjÿubeh}”(h]”h ]”h"]”h$]”h&]”uh1juh³hÊh´K?hjüubah}”(h]”h ]”h"]”h$]”h&]”uh1jphjøubah}”(h]”h ]”h"]”h$]”h&]”uh1jjhjgh²hh³Nh´Nubeh}”(h]”h ]”h"]”h$]”h&]”Œbullet”Œ-”uh1jeh³hÊh´K0hj,h²hubhÌ)”}”(hŒ^If required color or function is missing, please submit a patch to linux-leds@vger.kernel.org.”h]”(hŒCIf required color or function is missing, please submit a patch to ”…””}”(hjBh²hh³Nh´NubhŒ reference”“”)”}”(hŒlinux-leds@vger.kernel.org”h]”hŒlinux-leds@vger.kernel.org”…””}”(hjLh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”Œrefuri”Œ!mailto:linux-leds@vger.kernel.org”uh1jJhjBubhŒ.”…””}”(hjBh²hh³Nh´Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KAhj,h²hubhÌ)”}”(hXÀIt is possible that more than one LED with the same color and function will be required for given platform, differing only with an ordinal number. In this case it is preferable to just concatenate the predefined LED_FUNCTION_* name with required "-N" suffix in the driver. fwnode based drivers can use function-enumerator property for that and then the concatenation will be handled automatically by the LED core upon LED class device registration.”h]”hXÄIt is possible that more than one LED with the same color and function will be required for given platform, differing only with an ordinal number. In this case it is preferable to just concatenate the predefined LED_FUNCTION_* name with required â€œ-Nâ€ suffix in the driver. fwnode based drivers can use function-enumerator property for that and then the concatenation will be handled automatically by the LED core upon LED class device registration.”…””}”(hjfh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KDhj,h²hubhÌ)”}”(hX)LED subsystem has also a protection against name clash, that may occur when LED class device is created by a driver of hot-pluggable device and it doesn't provide unique devicename section. In this case numerical suffix (e.g. "_1", "_2", "_3" etc.) is added to the requested LED class device name.”h]”hX7LED subsystem has also a protection against name clash, that may occur when LED class device is created by a driver of hot-pluggable device and it doesnâ€™t provide unique devicename section. In this case numerical suffix (e.g. â€œ_1â€, â€œ_2â€, â€œ_3â€ etc.) is added to the requested LED class device name.”…””}”(hjth²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KKhj,h²hubhÌ)”}”(hXThere might be still LED class drivers around using vendor or product name for devicename, but this approach is now deprecated as it doesn't convey any added value. Product information can be found in other places in sysfs (see tools/leds/get_led_device_info.sh).”h]”hX There might be still LED class drivers around using vendor or product name for devicename, but this approach is now deprecated as it doesnâ€™t convey any added value. Product information can be found in other places in sysfs (see tools/leds/get_led_device_info.sh).”…””}”(hj‚h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KQhj,h²hubhÌ)”}”(hŒExamples of proper LED names:”h]”hŒExamples of proper LED names:”…””}”(hjh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KVhj,h²hubjL)”}”(hŒá- "red:disk" - "white:flash" - "red:indicator" - "phy1:green:wlan" - "phy3::wlan" - ":kbd_backlight" - "input5::kbd_backlight" - "input3::numlock" - "input3::scrolllock" - "input3::capslock" - "mmc1::status" - "white:status" ”h]”jf)”}”(hhh]”(jk)”}”(hŒ "red:disk"”h]”hÌ)”}”(hj§h]”hŒâ€œred:diskâ€”…””}”(hj©h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KXhj¥ubah}”(h]”h ]”h"]”h$]”h&]”uh1jjhj¢ubjk)”}”(hŒ "white:flash"”h]”hÌ)”}”(hj¾h]”hŒâ€œwhite:flashâ€”…””}”(hjÀh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KYhj¼ubah}”(h]”h ]”h"]”h$]”h&]”uh1jjhj¢ubjk)”}”(hŒ"red:indicator"”h]”hÌ)”}”(hjÕh]”hŒâ€œred:indicatorâ€”…””}”(hj×h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KZhjÓubah}”(h]”h ]”h"]”h$]”h&]”uh1jjhj¢ubjk)”}”(hŒ"phy1:green:wlan"”h]”hÌ)”}”(hjìh]”hŒâ€œphy1:green:wlanâ€”…””}”(hjîh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´K[hjêubah}”(h]”h ]”h"]”h$]”h&]”uh1jjhj¢ubjk)”}”(hŒ"phy3::wlan"”h]”hÌ)”}”(hjh]”hŒâ€œphy3::wlanâ€”…””}”(hjh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´K\hjubah}”(h]”h ]”h"]”h$]”h&]”uh1jjhj¢ubjk)”}”(hŒ":kbd_backlight"”h]”hÌ)”}”(hjh]”hŒâ€œ:kbd_backlightâ€”…””}”(hjh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´K]hjubah}”(h]”h ]”h"]”h$]”h&]”uh1jjhj¢ubjk)”}”(hŒ"input5::kbd_backlight"”h]”hÌ)”}”(hj1h]”hŒâ€œinput5::kbd_backlightâ€”…””}”(hj3h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´K^hj/ubah}”(h]”h ]”h"]”h$]”h&]”uh1jjhj¢ubjk)”}”(hŒ"input3::numlock"”h]”hÌ)”}”(hjHh]”hŒâ€œinput3::numlockâ€”…””}”(hjJh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´K_hjFubah}”(h]”h ]”h"]”h$]”h&]”uh1jjhj¢ubjk)”}”(hŒ"input3::scrolllock"”h]”hÌ)”}”(hj_h]”hŒâ€œinput3::scrolllockâ€”…””}”(hjah²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´K`hj]ubah}”(h]”h ]”h"]”h$]”h&]”uh1jjhj¢ubjk)”}”(hŒ"input3::capslock"”h]”hÌ)”}”(hjvh]”hŒâ€œinput3::capslockâ€”…””}”(hjxh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´Kahjtubah}”(h]”h ]”h"]”h$]”h&]”uh1jjhj¢ubjk)”}”(hŒ"mmc1::status"”h]”hÌ)”}”(hjh]”hŒâ€œmmc1::statusâ€”…””}”(hjh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´Kbhj‹ubah}”(h]”h ]”h"]”h$]”h&]”uh1jjhj¢ubjk)”}”(hŒ"white:status" ”h]”hÌ)”}”(hŒ"white:status"”h]”hŒâ€œwhite:statusâ€”…””}”(hj¦h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´Kchj¢ubah}”(h]”h ]”h"]”h$]”h&]”uh1jjhj¢ubeh}”(h]”h ]”h"]”h$]”h&]”j@jAuh1jeh³hÊh´KXhjžubah}”(h]”h ]”h"]”h$]”h&]”uh1jKh³hÊh´KXhj,h²hubhÌ)”}”(hXdget_led_device_info.sh script can be used for verifying if the LED name meets the requirements pointed out here. It performs validation of the LED class devicename sections and gives hints on expected value for a section in case the validation fails for it. So far the script supports validation of associations between LEDs and following types of devices:”h]”hXdget_led_device_info.sh script can be used for verifying if the LED name meets the requirements pointed out here. It performs validation of the LED class devicename sections and gives hints on expected value for a section in case the validation fails for it. So far the script supports validation of associations between LEDs and following types of devices:”…””}”(hjÆh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´Kehj,h²hubjL)”}”(hŒ2- input devices - ieee80211 compliant USB devices ”h]”jf)”}”(hhh]”(jk)”}”(hŒ input devices”h]”hÌ)”}”(hjÝh]”hŒ input devices”…””}”(hjßh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KkhjÛubah}”(h]”h ]”h"]”h$]”h&]”uh1jjhjØubjk)”}”(hŒ ieee80211 compliant USB devices ”h]”hÌ)”}”(hŒieee80211 compliant USB devices”h]”hŒieee80211 compliant USB devices”…””}”(hjöh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´Klhjòubah}”(h]”h ]”h"]”h$]”h&]”uh1jjhjØubeh}”(h]”h ]”h"]”h$]”h&]”j@jAuh1jeh³hÊh´KkhjÔubah}”(h]”h ]”h"]”h$]”h&]”uh1jKh³hÊh´Kkhj,h²hubhÌ)”}”(hŒ!The script is open to extensions.”h]”hŒ!The script is open to extensions.”…””}”(hjh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´Knhj,h²hubhÌ)”}”(hXdThere have been calls for LED properties such as color to be exported as individual led class attributes. As a solution which doesn't incur as much overhead, I suggest these become part of the device name. The naming scheme above leaves scope for further attributes should they be needed. If sections of the name don't apply, just leave that section blank.”h]”hXhThere have been calls for LED properties such as color to be exported as individual led class attributes. As a solution which doesnâ€™t incur as much overhead, I suggest these become part of the device name. The naming scheme above leaves scope for further attributes should they be needed. If sections of the name donâ€™t apply, just leave that section blank.”…””}”(hj$h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´Kphj,h²hubeh}”(h]”Œled-device-naming”ah ]”h"]”Œled device naming”ah$]”h&]”uh1hµhh·h²hh³hÊh´K*ubh¶)”}”(hhh]”(h»)”}”(hŒ,Keyboard backlight control LED Device Naming”h]”hŒ,Keyboard backlight control LED Device Naming”…””}”(hj=h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hºhj:h²hh³hÊh´KxubhÌ)”}”(hXXFor backlit keyboards with a single brightness / color settings a single (multicolor) LED class device should be used to allow userspace to change the backlight brightness (and if possible the color). This LED class device must use "kbd_backlight" for the function part of the LED class device name. IOW the name must end with ":kbd_backlight".”h]”hX`For backlit keyboards with a single brightness / color settings a single (multicolor) LED class device should be used to allow userspace to change the backlight brightness (and if possible the color). This LED class device must use â€œkbd_backlightâ€ for the function part of the LED class device name. IOW the name must end with â€œ:kbd_backlightâ€.”…””}”(hjKh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´Kzhj:h²hubhÌ)”}”(hŒ˜For backlit keyboards with multiple control zones, one (multicolor) LED class device should be used per zone. These LED class devices' name must follow:”h]”hŒšFor backlit keyboards with multiple control zones, one (multicolor) LED class device should be used per zone. These LED class devicesâ€™ name must follow:”…””}”(hjYh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´K€hj:h²hubjL)”}”(hŒ7"::kbd_zoned_backlight-" ”h]”hÌ)”}”(hŒ6"::kbd_zoned_backlight-"”h]”hŒ:â€œ::kbd_zoned_backlight-â€”…””}”(hjkh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´Kƒhjgubah}”(h]”h ]”h"]”h$]”h&]”uh1jKh³hÊh´Kƒhj:h²hubhÌ)”}”(hŒEand must be the same for all zones of the same keyboard.”h]”hŒEand must be the same for all zones of the same keyboard.”…””}”(hjh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´K…hj:h²hubhÌ)”}”(hŒ¹ should be descriptive of which part of the keyboard backlight the zone covers and should be suitable for userspace to show to an end user in an UI for controlling the zones.”h]”hŒ¹ should be descriptive of which part of the keyboard backlight the zone covers and should be suitable for userspace to show to an end user in an UI for controlling the zones.”…””}”(hjh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´K‡hj:h²hubhÌ)”}”(hŒWhere possible should be a value already used by other zoned keyboards with a similar or identical zone layout, e.g.:”h]”hŒWhere possible should be a value already used by other zoned keyboards with a similar or identical zone layout, e.g.:”…””}”(hj›h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´K‹hj:h²hubhÌ)”}”(hŒë::kbd_zoned_backlight-right ::kbd_zoned_backlight-middle ::kbd_zoned_backlight-left ::kbd_zoned_backlight-corners ::kbd_zoned_backlight-wasd”h]”hŒë::kbd_zoned_backlight-right ::kbd_zoned_backlight-middle ::kbd_zoned_backlight-left ::kbd_zoned_backlight-corners ::kbd_zoned_backlight-wasd”…””}”(hj©h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KŽhj:h²hubhÌ)”}”(hŒor:”h]”hŒor:”…””}”(hj·h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´K”hj:h²hubhÌ)”}”(hŒì::kbd_zoned_backlight-main ::kbd_zoned_backlight-cursor ::kbd_zoned_backlight-numpad ::kbd_zoned_backlight-corners ::kbd_zoned_backlight-wasd”h]”hŒì::kbd_zoned_backlight-main ::kbd_zoned_backlight-cursor ::kbd_zoned_backlight-numpad ::kbd_zoned_backlight-corners ::kbd_zoned_backlight-wasd”…””}”(hjÅh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´K–hj:h²hubhÌ)”}”(hX2Note that this is intended for keyboards with a limited number of zones, keyboards with per key addressable backlighting must not use LED class devices since the sysfs API is not suitable for rapidly change multiple LEDs in one "commit" as is necessary to do animations / special effects on such keyboards.”h]”hX6Note that this is intended for keyboards with a limited number of zones, keyboards with per key addressable backlighting must not use LED class devices since the sysfs API is not suitable for rapidly change multiple LEDs in one â€œcommitâ€ as is necessary to do animations / special effects on such keyboards.”…””}”(hjÓh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´Kœhj:h²hubhÌ)”}”(hŒ4An exception to the rule that all zones must follow:”h]”hŒ4An exception to the rule that all zones must follow:”…””}”(hjáh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´K¡hj:h²hubjL)”}”(hŒ7"::kbd_zoned_backlight-" ”h]”hÌ)”}”(hŒ6"::kbd_zoned_backlight-"”h]”hŒ:â€œ::kbd_zoned_backlight-â€”…””}”(hjóh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´K£hjïubah}”(h]”h ]”h"]”h$]”h&]”uh1jKh³hÊh´K£hj:h²hubhÌ)”}”(hXºis made for the special case where there is a single big zone which controls the backlighting of almost all of the keyboard and there are some small areas with separate control, like just the 4 cursor keys, or the WASD keys. In this case the main zone should use 'kbd_backlight' for the function part of the name for compatibility with (older) userspace code which is not aware of the "kbd_zoned_backlight-" function naming scheme.”h]”hXÂis made for the special case where there is a single big zone which controls the backlighting of almost all of the keyboard and there are some small areas with separate control, like just the 4 cursor keys, or the WASD keys. In this case the main zone should use â€˜kbd_backlightâ€™ for the function part of the name for compatibility with (older) userspace code which is not aware of the â€œkbd_zoned_backlight-â€ function naming scheme.”…””}”(hjh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´K¥hj:h²hubhÌ)”}”(hŒbWhile the smaller zones should use the new zoned naming scheme. Such a setup would result in e.g.:”h]”hŒbWhile the smaller zones should use the new zoned naming scheme. Such a setup would result in e.g.:”…””}”(hjh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´K¬hj:h²hubhÌ)”}”(hŒP::kbd_backlight ::kbd_zoned_backlight-wasd”h]”hŒP::kbd_backlight ::kbd_zoned_backlight-wasd”…””}”(hj#h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´K¯hj:h²hubhÌ)”}”(hŒ“"kbd_zoned_backlight-" aware userspace should be aware of this exception and check for a main zone with a "kbd_backlight" function-name.”h]”hŒ›â€œkbd_zoned_backlight-â€ aware userspace should be aware of this exception and check for a main zone with a â€œkbd_backlightâ€ function-name.”…””}”(hj1h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´K²hj:h²hubeh}”(h]”Œ,keyboard-backlight-control-led-device-naming”ah ]”h"]”Œ,keyboard backlight control led device naming”ah$]”h&]”uh1hµhh·h²hh³hÊh´Kxubh¶)”}”(hhh]”(h»)”}”(hŒBrightness setting API”h]”hŒBrightness setting API”…””}”(hjJh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hºhjGh²hh³hÊh´K·ubhÌ)”}”(hŒ@LED subsystem core exposes following API for setting brightness:”h]”hŒ@LED subsystem core exposes following API for setting brightness:”…””}”(hjXh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´K¹hjGh²hubjL)”}”(hX¦- led_set_brightness: it is guaranteed not to sleep, passing LED_OFF stops blinking, - led_set_brightness_sync: for use cases when immediate effect is desired - it can block the caller for the time required for accessing device registers and can sleep, passing LED_OFF stops hardware blinking, returns -EBUSY if software blink fallback is enabled. ”h]”jf)”}”(hhh]”(jk)”}”(hŒgled_set_brightness: it is guaranteed not to sleep, passing LED_OFF stops blinking, ”h]”jq)”}”(hhh]”jv)”}”(hŒSled_set_brightness: it is guaranteed not to sleep, passing LED_OFF stops blinking, ”h]”(j|)”}”(hŒled_set_brightness:”h]”hŒled_set_brightness:”…””}”(hjxh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j{h³hÊh´K½hjtubjŒ)”}”(hhh]”hÌ)”}”(hŒ>it is guaranteed not to sleep, passing LED_OFF stops blinking,”h]”hŒ>it is guaranteed not to sleep, passing LED_OFF stops blinking,”…””}”(hj‰h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´K¼hj†ubah}”(h]”h ]”h"]”h$]”h&]”uh1j‹hjtubeh}”(h]”h ]”h"]”h$]”h&]”uh1juh³hÊh´K½hjqubah}”(h]”h ]”h"]”h$]”h&]”uh1jphjmubah}”(h]”h ]”h"]”h$]”h&]”uh1jjhjjubjk)”}”(hX.led_set_brightness_sync: for use cases when immediate effect is desired - it can block the caller for the time required for accessing device registers and can sleep, passing LED_OFF stops hardware blinking, returns -EBUSY if software blink fallback is enabled. ”h]”jq)”}”(hhh]”jv)”}”(hXled_set_brightness_sync: for use cases when immediate effect is desired - it can block the caller for the time required for accessing device registers and can sleep, passing LED_OFF stops hardware blinking, returns -EBUSY if software blink fallback is enabled. ”h]”(j|)”}”(hŒled_set_brightness_sync:”h]”hŒled_set_brightness_sync:”…””}”(hjºh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j{h³hÊh´KÄhj¶ubjŒ)”}”(hhh]”hÌ)”}”(hŒëfor use cases when immediate effect is desired - it can block the caller for the time required for accessing device registers and can sleep, passing LED_OFF stops hardware blinking, returns -EBUSY if software blink fallback is enabled.”h]”hŒëfor use cases when immediate effect is desired - it can block the caller for the time required for accessing device registers and can sleep, passing LED_OFF stops hardware blinking, returns -EBUSY if software blink fallback is enabled.”…””}”(hjËh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KÀhjÈubah}”(h]”h ]”h"]”h$]”h&]”uh1j‹hj¶ubeh}”(h]”h ]”h"]”h$]”h&]”uh1juh³hÊh´KÄhj³ubah}”(h]”h ]”h"]”h$]”h&]”uh1jphj¯ubah}”(h]”h ]”h"]”h$]”h&]”uh1jjhjjubeh}”(h]”h ]”h"]”h$]”h&]”j@jAuh1jeh³hÊh´K»hjfubah}”(h]”h ]”h"]”h$]”h&]”uh1jKh³hÊh´K»hjGh²hubeh}”(h]”Œbrightness-setting-api”ah ]”h"]”Œbrightness setting api”ah$]”h&]”uh1hµhh·h²hh³hÊh´K·ubh¶)”}”(hhh]”(h»)”}”(hŒLED registration API”h]”hŒLED registration API”…””}”(hjh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hºhjh²hh³hÊh´KÇubhÌ)”}”(hX>A driver wanting to register a LED classdev for use by other drivers / userspace needs to allocate and fill a led_classdev struct and then call `[devm_]led_classdev_register`. If the non devm version is used the driver must call led_classdev_unregister from its remove function before free-ing the led_classdev struct.”h]”(hŒA driver wanting to register a LED classdev for use by other drivers / userspace needs to allocate and fill a led_classdev struct and then call ”…””}”(hjh²hh³Nh´NubhŒtitle_reference”“”)”}”(hŒ`[devm_]led_classdev_register`”h]”hŒ[devm_]led_classdev_register”…””}”(hj h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jhjubhŒ. If the non devm version is used the driver must call led_classdev_unregister from its remove function before free-ing the led_classdev struct.”…””}”(hjh²hh³Nh´Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KÉhjh²hubhÌ)”}”(hX\If the driver can detect hardware initiated brightness changes and thus wants to have a brightness_hw_changed attribute then the LED_BRIGHT_HW_CHANGED flag must be set in flags before registering. Calling led_classdev_notify_brightness_hw_changed on a classdev not registered with the LED_BRIGHT_HW_CHANGED flag is a bug and will trigger a WARN_ON.”h]”hX\If the driver can detect hardware initiated brightness changes and thus wants to have a brightness_hw_changed attribute then the LED_BRIGHT_HW_CHANGED flag must be set in flags before registering. Calling led_classdev_notify_brightness_hw_changed on a classdev not registered with the LED_BRIGHT_HW_CHANGED flag is a bug and will trigger a WARN_ON.”…””}”(hj8h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KÏhjh²hubeh}”(h]”Œled-registration-api”ah ]”h"]”Œled registration api”ah$]”h&]”uh1hµhh·h²hh³hÊh´KÇubh¶)”}”(hhh]”(h»)”}”(hŒ"Hardware accelerated blink of LEDs”h]”hŒ"Hardware accelerated blink of LEDs”…””}”(hjQh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hºhjNh²hh³hÊh´KÖubhÌ)”}”(hXHSome LEDs can be programmed to blink without any CPU interaction. To support this feature, a LED driver can optionally implement the blink_set() function (see ). To set an LED to blinking, however, it is better to use the API function led_blink_set(), as it will check and implement software fallback if necessary.”h]”hXHSome LEDs can be programmed to blink without any CPU interaction. To support this feature, a LED driver can optionally implement the blink_set() function (see ). To set an LED to blinking, however, it is better to use the API function led_blink_set(), as it will check and implement software fallback if necessary.”…””}”(hj_h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KØhjNh²hubhÌ)”}”(hŒ®To turn off blinking, use the API function led_brightness_set() with brightness value LED_OFF, which should stop any software timers that may have been required for blinking.”h]”hŒ®To turn off blinking, use the API function led_brightness_set() with brightness value LED_OFF, which should stop any software timers that may have been required for blinking.”…””}”(hjmh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KÞhjNh²hubhÌ)”}”(hXThe blink_set() function should choose a user friendly blinking value if it is called with `*delay_on==0` && `*delay_off==0` parameters. In this case the driver should give back the chosen value through delay_on and delay_off parameters to the leds subsystem.”h]”(hŒ[The blink_set() function should choose a user friendly blinking value if it is called with ”…””}”(hj{h²hh³Nh´Nubj)”}”(hŒ`*delay_on==0`”h]”hŒ*delay_on==0”…””}”(hjƒh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jhj{ubhŒ && ”…””}”(hj{h²hh³Nh´Nubj)”}”(hŒ`*delay_off==0`”h]”hŒ *delay_off==0”…””}”(hj•h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jhj{ubhŒ‡ parameters. In this case the driver should give back the chosen value through delay_on and delay_off parameters to the leds subsystem.”…””}”(hj{h²hh³Nh´Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KâhjNh²hubhÌ)”}”(hŒ²Setting the brightness to zero with brightness_set() callback function should completely turn off the LED and cancel the previously programmed hardware blinking function, if any.”h]”hŒ²Setting the brightness to zero with brightness_set() callback function should completely turn off the LED and cancel the previously programmed hardware blinking function, if any.”…””}”(hjh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KçhjNh²hubeh}”(h]”Œ"hardware-accelerated-blink-of-leds”ah ]”h"]”Œ"hardware accelerated blink of leds”ah$]”h&]”uh1hµhh·h²hh³hÊh´KÖubh¶)”}”(hhh]”(h»)”}”(hŒHardware driven LEDs”h]”hŒHardware driven LEDs”…””}”(hjÆh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hºhjÃh²hh³hÊh´KìubhÌ)”}”(hXSome LEDs can be programmed to be driven by hardware. This is not limited to blink but also to turn off or on autonomously. To support this feature, a LED needs to implement various additional ops and needs to declare specific support for the supported triggers.”h]”hXSome LEDs can be programmed to be driven by hardware. This is not limited to blink but also to turn off or on autonomously. To support this feature, a LED needs to implement various additional ops and needs to declare specific support for the supported triggers.”…””}”(hjÔh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KîhjÃh²hubhÌ)”}”(hŒ7With hw control we refer to the LED driven by hardware.”h]”hŒ7With hw control we refer to the LED driven by hardware.”…””}”(hjâh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KóhjÃh²hubhÌ)”}”(hŒALED driver must define the following value to support hw control:”h]”hŒALED driver must define the following value to support hw control:”…””}”(hjðh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KõhjÃh²hubjL)”}”(hŒi- hw_control_trigger: unique trigger name supported by the LED in hw control mode. ”h]”jf)”}”(hhh]”jk)”}”(hŒchw_control_trigger: unique trigger name supported by the LED in hw control mode. ”h]”jq)”}”(hhh]”jv)”}”(hŒQhw_control_trigger: unique trigger name supported by the LED in hw control mode. ”h]”(j|)”}”(hŒhw_control_trigger:”h]”hŒhw_control_trigger:”…””}”(hjh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j{h³hÊh´KùhjubjŒ)”}”(hhh]”hÌ)”}”(hŒubhÌ)”}”(hŒüThe LED Trigger core cannot be a module as the simple trigger functions would cause nightmare dependency issues. I see this as a minor issue compared to the benefits the simple trigger functionality brings. The rest of the LED subsystem can be modular.”h]”hŒüThe LED Trigger core cannot be a module as the simple trigger functions would cause nightmare dependency issues. I see this as a minor issue compared to the benefits the simple trigger functionality brings. The rest of the LED subsystem can be modular.”…””}”(hj] h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´M@hjL h²hubeh}”(h]”Œknown-issues”ah ]”h"]”Œknown issues”ah$]”h&]”uh1hµhh·h²hh³hÊh´M>ubeh}”(h]”Œled-handling-under-linux”ah ]”h"]”Œled handling under linux”ah$]”h&]”uh1hµhhh²hh³hÊh´Kubeh}”(h]”h ]”h"]”h$]”h&]”Œsource”hÊuh1hŒcurrent_source”NŒcurrent_line”NŒsettings”Œdocutils.frontend”ŒValues”“”)”}”(hºNŒ generator”NŒ datestamp”NŒsource_link”NŒ source_url”NŒ toc_backlinks”Œentry”Œfootnote_backlinks”KŒ sectnum_xform”KŒstrip_comments”NŒstrip_elements_with_classes”NŒ strip_classes”NŒreport_level”KŒ halt_level”KŒexit_status_level”KŒdebug”NŒwarning_stream”NŒ traceback”ˆŒinput_encoding”Œ utf-8-sig”Œinput_encoding_error_handler”Œstrict”Œoutput_encoding”Œutf-8”Œoutput_encoding_error_handler”jž Œerror_encoding”Œutf-8”Œerror_encoding_error_handler”Œbackslashreplace”Œ language_code”Œen”Œrecord_dependencies”NŒconfig”NŒ id_prefix”hŒauto_id_prefix”Œid”Œ dump_settings”NŒdump_internals”NŒdump_transforms”NŒdump_pseudo_xml”NŒexpose_internals”NŒstrict_visitor”NŒ_disable_config”NŒ_source”hÊŒ_destination”NŒ _config_files”]”Œ7/var/lib/git/docbuild/linux/Documentation/docutils.conf”aŒfile_insertion_enabled”ˆŒraw_enabled”KŒline_length_limit”M'Œpep_references”NŒpep_base_url”Œhttps://peps.python.org/”Œpep_file_url_template”Œpep-%04d”Œrfc_references”NŒrfc_base_url”Œ&https://datatracker.ietf.org/doc/html/”Œ tab_width”KŒtrim_footnote_reference_space”‰Œsyntax_highlight”Œlong”Œsmart_quotes”ˆŒsmartquotes_locales”]”Œcharacter_level_inline_markup”‰Œdoctitle_xform”‰Œ docinfo_xform”KŒsectsubtitle_xform”‰Œ image_loading”Œlink”Œembed_stylesheet”‰Œcloak_email_addresses”ˆŒsection_self_link”‰Œenv”NubŒreporter”NŒindirect_targets”]”Œsubstitution_defs”}”Œsubstitution_names”}”Œrefnames”}”Œrefids”}”Œnameids”}”(jx ju j)j&j7j4jDjAjjÿjKjHjÀj½jI jF jp jm uŒ nametypes”}”(jx ‰j)‰j7‰jD‰j‰jK‰jÀ‰jI ‰jp ‰uh}”(ju h·j&jj4j,jAj:jÿjGjHjj½jNjF jÃjm jL uŒ footnote_refs”}”Œ citation_refs”}”Œ autofootnotes”]”Œautofootnote_refs”]”Œsymbol_footnotes”]”Œsymbol_footnote_refs”]”Œ footnotes”]”Œ citations”]”Œautofootnote_start”KŒsymbol_footnote_start”KŒ id_counter”Œcollections”ŒCounter”“”}”…”R”Œparse_messages”]”Œtransform_messages”]”Œtransformer”NŒinclude_log”]”Œ decoration”Nh²hub.