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authorLudovic Desroches <ludovic.desroches@microchip.com>2018-06-29 10:15:33 +0200
committerLinus Walleij <linus.walleij@linaro.org>2018-07-16 14:46:11 +0200
commitff10e353a4c0c83a28c89c182462b3c8dc7f70cc (patch)
tree332bb94416582cc5176ada527626285507ba694c /Documentation/devicetree/bindings/pinctrl
parentpinctrl: mt7622: mark expected switch fall-through (diff)
downloadlinux-dev-ff10e353a4c0c83a28c89c182462b3c8dc7f70cc.tar.xz
linux-dev-ff10e353a4c0c83a28c89c182462b3c8dc7f70cc.zip
pinctrl: at91-pio4: add support for drive strength
Add support for the drive strength configuration. Usually, this value is expressed in mA. Since the numeric value depends on VDDIOP voltage, a value we can't retrieve at runtime, the controller uses low, medium and high to define the drive strength. The PIO controller accepts two values for the low drive configuration: 0 and 1. Most of the time, we don't care about the drive strength. So we keep the default value which is 0. The drive strength is advertised through the sysfs only when it has been explicitly set in the device tree i.e. if its value is different from 0. Signed-off-by: Ludovic Desroches <ludovic.desroches@microchip.com> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'Documentation/devicetree/bindings/pinctrl')
-rw-r--r--Documentation/devicetree/bindings/pinctrl/atmel,at91-pio4-pinctrl.txt3
1 files changed, 3 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/pinctrl/atmel,at91-pio4-pinctrl.txt b/Documentation/devicetree/bindings/pinctrl/atmel,at91-pio4-pinctrl.txt
index 61ac75706cc9..04d16fb69eb7 100644
--- a/Documentation/devicetree/bindings/pinctrl/atmel,at91-pio4-pinctrl.txt
+++ b/Documentation/devicetree/bindings/pinctrl/atmel,at91-pio4-pinctrl.txt
@@ -36,6 +36,8 @@ Optional properties:
- GENERIC_PINCONFIG: generic pinconfig options to use, bias-disable,
bias-pull-down, bias-pull-up, drive-open-drain, input-schmitt-enable,
input-debounce, output-low, output-high.
+- atmel,drive-strength: 0 or 1 for low drive, 2 for medium drive and 3 for
+high drive. The default value is low drive.
Example:
@@ -66,6 +68,7 @@ Example:
pinmux = <PIN_PB0>,
<PIN_PB5>;
bias-pull-up;
+ atmel,drive-strength = <ATMEL_PIO_DRVSTR_ME>;
};
pinctrl_sdmmc1_default: sdmmc1_default {