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Commit 70637a6d authored by Heiko Stübner's avatar Heiko Stübner Committed by Linus Walleij
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pinctrl: more clarifications for generic pull configs 



PULL_PIN_DEFAULT is meant for hardware completely hiding any pull
settings from the driver, so that it's really only possible to turn
the pull on or off, but it not being possible to determine any
pull settings from software.

Also the binding-documentation for the pull arguments did not match
the changes to the expected values.

Signed-off-by: default avatarHeiko Stuebner <heiko@sntech.de>
Reviewed-by: default avatarJames Hogan <james.hogan@imgtec.com>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent ad42fc6c

Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt

+2 −3
Original line number Diff line number Diff line
@@ -165,9 +165,8 @@ output-high - set the pin to output mode with high level 


Arguments for parameters:



- bias-pull-up, -down and -pin-default take as optional argument 0 to disable

  the pull, on hardware supporting it the pull strength in Ohm. bias-disable

  will also disable any active pull.

- bias-pull-up, -down and -pin-default take as optional argument on hardware

  supporting it the pull strength in Ohm. bias-disable will disable the pull.



- drive-strength takes as argument the target strength in mA.

include/linux/pinctrl/pinconf-generic.h

+4 −1
Original line number Diff line number Diff line
@@ -41,7 +41,10 @@ 
 *	impedance to GROUND). If the argument is != 0 pull-down is enabled,

 *	if it is 0, pull-down is total, i.e. the pin is connected to GROUND.

 * @PIN_CONFIG_BIAS_PULL_PIN_DEFAULT: the pin will be pulled up or down based

 *	on embedded knowledge of the controller, like current mux function.

 *	on embedded knowledge of the controller hardware, like current mux

 *	function. The pull direction and possibly strength too will normally

 *	be decided completely inside the hardware block and not be readable

 *	from the kernel side.

 *	If the argument is != 0 pull up/down is enabled, if it is 0, the

 *	configuration is ignored. The proper way to disable it is to use

 *	@PIN_CONFIG_BIAS_DISABLE.