[PATCH] pinctrl: establish pull-up/pull-down terminology
From: Linus Walleij
Date: Sun Jun 16 2013 - 07:11:53 EST
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 Stübner <heiko@xxxxxxxxx>
Cc: James Hogan <james.hogan@xxxxxxxxxx>
Cc: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
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
@@ -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 alternative
- * slew rate to use.
+ * this parameter (on a custom format) tells the driver which alternative
+ * 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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