RFC series improving common LED binding parsing support Qucik grep for 'for_each' or 'linux,default-trigger' says it all. Multiple LED controller drivers implement the very similar looping through the child DT nodes in order to locate the LED nodes and read and support the common LED dt bindings. Implementing this same stuff for all LED controllers gets old pretty fast. This RFC contains 3 suggestions: Simplest is adding support for parsing the linux,default-trigger, and default-state DT properties in led-core. More interesting part is adding correct LED DT node lookup in LED core. This RFC uses LED DT node names as a 'key' in a same way regulator framework does for regulators. The thing is that this approach requires the LED controller binding to dictate allowed LED node names - which may or may not be doable. I need your help to evaluate this and suggest better options :) If we still look at the regulators, the regulator core did originally use "regulator-core" property to do driver data/DT node pairing - but has since then changed the approach to using the DT node names. Last and least clear point is isolating the led_classdev to be owned by the LED core. Controller drivers should pretty much never touch it after the initialization. So one approach would be that drivers only provided initialization data and operations to the core. The patch series contains the led-core and led-class changes which introduce (yet another) APIs for registering led class device to core. Adding new interface is probably not the best option - one might consider changing the (devm_)led_classdev_register_ext to do what this new RFC API is doing. In addition to core changes this series converted two (randomly selected) existing drivers to use the new API. This can give an overview how offloading the DT parsing to core could simplify many of the LED controlled drivers. Patches HAVE NOT BEEN TESTED other than for compiling. They are only intended to be a starting point for discussion - and if the ideas are seen worthy - then the patches should be further worked and properly tested before being applied. Matti Vaittinen (5): leds: Add common LED binding parsing support to LED class/core dt-bindings: an30259a: example for using fixed LED node names. leds: an30259a: Offload DT node locating and parsing to core dt-bindings: lm3692x: example for using fixed LED node names. leds: lm3692x: Offload DT node locating and parsing to core .../bindings/leds/leds-an30259a.txt | 9 +- .../devicetree/bindings/leds/leds-lm3692x.txt | 4 +- drivers/leds/led-class.c | 247 +++++++++++++++++- drivers/leds/led-core.c | 111 +++++--- drivers/leds/leds-an30259a.c | 181 ++++++------- drivers/leds/leds-lm3692x.c | 75 +++--- include/linux/leds.h | 144 +++++++++- 7 files changed, 586 insertions(+), 185 deletions(-) -- 2.21.0 -- Matti Vaittinen, Linux device drivers ROHM Semiconductors, Finland SWDC Kiviharjunlenkki 1E 90220 OULU FINLAND ~~~ "I don't think so," said Rene Descartes. Just then he vanished ~~~ Simon says - in Latin please. ~~~ "non cogito me" dixit Rene Descarte, deinde evanescavit ~~~ Thanks to Simon Glass for the translation =]
