base-files: gpio switch: set output value with direction
authorMathias Kresin <dev@kresin.me>
Thu, 21 Dec 2017 00:06:42 +0000 (01:06 +0100)
committerMathias Kresin <dev@kresin.me>
Tue, 9 Jan 2018 21:05:46 +0000 (22:05 +0100)
Use the "low" and "high" values to configure the GPIO as an output with
that initial value. It ensures that the gpio doesn't have a unwanted value
during the time the direction is set to ouput and the actual value is
applied.

We don't need to take care of the GPIO polarity for now, since our
exported GPIOs are always active low.

Signed-off-by: Mathias Kresin <dev@kresin.me>
package/base-files/Makefile
package/base-files/files/etc/init.d/gpio_switch

index a7cc4ca..87e02ff 100644 (file)
@@ -12,7 +12,7 @@ include $(INCLUDE_DIR)/version.mk
 include $(INCLUDE_DIR)/feeds.mk
 
 PKG_NAME:=base-files
-PKG_RELEASE:=181
+PKG_RELEASE:=182
 PKG_FLAGS:=nonshared
 
 PKG_FILE_DEPENDS:=$(PLATFORM_DIR)/ $(GENERIC_PLATFORM_DIR)/base-files/
index 5a62be9..b67950a 100755 (executable)
@@ -22,10 +22,9 @@ load_gpio_switch()
                echo "$gpio_pin" >/sys/class/gpio/export
                # we need to wait a bit until the GPIO appears
                [ -d "$gpio_path" ] || sleep 1
-               echo out >"$gpio_path/direction"
        }
-       # write 0 or 1 to the "value" field
-       { [ "$value" = "0" ] && echo "0" || echo "1"; } >"$gpio_path/value"
+       # set the pin to output with high or low pin value
+       { [ "$value" = "0" ] && echo "high" || echo "low"; } >"$gpio_path/direction"
 }
 
 service_triggers()