Re: [PATCH] pinctrl: establish pull-up/pull-down terminology
From: Heiko StÃbner
Date: Sun Jun 16 2013 - 10:40:07 EST
Am Sonntag, 16. Juni 2013, 12:45:48 schrieb Linus Walleij:
> From: Linus Walleij <linus.walleij@xxxxxxxxxx>
> It is counter-intuitive to have "0" mean disable in a boolean
> manner for electronic properties of pins such as pull-up and
> pull-down. Therefore, define that a pull-up/pull-down argument
> of 0 to such a generic option means that the pin is
> short-circuited to VDD or GROUND. Pull disablement shall be
> done using PIN_CONFIG_BIAS_DISABLE.
> Cc: Heiko Stïbner <heiko@xxxxxxxxx>
> Cc: James Hogan <james.hogan@xxxxxxxxxx>
> Cc: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
very nice :-)
Acked-by: Heiko Stuebner <heiko@xxxxxxxxx>
> include/linux/pinctrl/pinconf-generic.h | 13 +++++++------
> 1 file changed, 7 insertions(+), 6 deletions(-)
> diff --git a/include/linux/pinctrl/pinconf-generic.h
> b/include/linux/pinctrl/pinconf-generic.h index d414a77..67780f5 100644
> --- a/include/linux/pinctrl/pinconf-generic.h
> +++ b/include/linux/pinctrl/pinconf-generic.h
> @@ -36,14 +36,15 @@
> * tristate. The argument is ignored.
> * @PIN_CONFIG_BIAS_PULL_UP: the pin will be pulled up (usually with high
> * impedance to VDD). If the argument is != 0 pull-up is enabled,
> - * if it is 0, pull-up is disabled.
> + * if it is 0, pull-up it total, i.e. the pin is connected to VDD.
> * @PIN_CONFIG_BIAS_PULL_DOWN: the pin will be pulled down (usually with
> high * impedance to GROUND). If the argument is != 0 pull-down is enabled,
> - * if it is 0, pull-down is disabled.
> + * 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. - * If the argument is != 0 pull up/down is enabled, if it is 0,
> - * the pull is disabled.
> + * 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.
> * @PIN_CONFIG_DRIVE_PUSH_PULL: the pin will be driven actively high and
> * low, this is the most typical case and is typically achieved with two
> * active transistors on the output. Setting this config will enable
> @@ -72,8 +73,8 @@
> * supplies, the argument to this parameter (on a custom format) tells
> * the driver which alternative power source to use.
> * @PIN_CONFIG_SLEW_RATE: if the pin can select slew rate, the argument to
> - * this parameter (on a custom format) tells the driver which
> - * slew rate to use.
> + * this parameter (on a custom format) tells the driver which
> + * slew rate to use.
> * @PIN_CONFIG_LOW_POWER_MODE: this will configure the pin for low power
> * operation, if several modes of operation are supported these can be
> * passed in the argument on a custom form, else just use argument 1
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