Created
June 25, 2015 11:23
-
-
Save pelwell/e4c5662c331fcae1e707 to your computer and use it in GitHub Desktop.
Patch to support gpio-poweroff on the Pi
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| From ac6797373064264c76d839bfe8e9a3c68f828998 Mon Sep 17 00:00:00 2001 | |
| From: Phil Elwell <phil@raspberrypi.org> | |
| Date: Thu, 25 Jun 2015 12:16:11 +0100 | |
| Subject: [PATCH] gpio-poweroff: Allow it to work on Raspberry Pi | |
| The Raspberry Pi firmware manages the power-down and reboot | |
| process. To do this it installs a pm_power_off handler, causing | |
| the gpio-poweroff module to abort the probe function. | |
| This patch introduces a "force" DT property that overrides that | |
| behaviour, and also adds a DT overlay to enable and control it. | |
| Note that running in an active-low configuration (DT parameter | |
| "active_low") requires a custom dt-blob.bin and probably won't | |
| allow a reboot without switching off, so an external inversion | |
| of the trigger signal may be preferable. | |
| --- | |
| arch/arm/boot/dts/overlays/Makefile | 1 + | |
| arch/arm/boot/dts/overlays/README | 13 +++++++++ | |
| .../boot/dts/overlays/gpio-poweroff-overlay.dts | 34 ++++++++++++++++++++++ | |
| drivers/power/reset/gpio-poweroff.c | 17 +++++++---- | |
| 4 files changed, 59 insertions(+), 6 deletions(-) | |
| create mode 100644 arch/arm/boot/dts/overlays/gpio-poweroff-overlay.dts | |
| diff --git a/arch/arm/boot/dts/overlays/Makefile b/arch/arm/boot/dts/overlays/Makefile | |
| index 19eef3c..a1397c7 100644 | |
| --- a/arch/arm/boot/dts/overlays/Makefile | |
| +++ b/arch/arm/boot/dts/overlays/Makefile | |
| @@ -16,6 +16,7 @@ dtb-$(RPI_DT_OVERLAYS) += ads7846-overlay.dtb | |
| dtb-$(RPI_DT_OVERLAYS) += bmp085_i2c-sensor-overlay.dtb | |
| dtb-$(RPI_DT_OVERLAYS) += dht11-overlay.dtb | |
| dtb-$(RPI_DT_OVERLAYS) += enc28j60-overlay.dtb | |
| +dtb-$(RPI_DT_OVERLAYS) += gpio-poweroff-overlay.dtb | |
| dtb-$(RPI_DT_OVERLAYS) += hifiberry-amp-overlay.dtb | |
| dtb-$(RPI_DT_OVERLAYS) += hifiberry-dac-overlay.dtb | |
| dtb-$(RPI_DT_OVERLAYS) += hifiberry-dacplus-overlay.dtb | |
| diff --git a/arch/arm/boot/dts/overlays/README b/arch/arm/boot/dts/overlays/README | |
| index 9406cf3..0ed7094 100644 | |
| --- a/arch/arm/boot/dts/overlays/README | |
| +++ b/arch/arm/boot/dts/overlays/README | |
| @@ -192,6 +192,19 @@ Params: int_pin GPIO used for INT (default 25) | |
| speed SPI bus speed (default 12000000) | |
| +Name: gpio-poweroff | |
| +Info: Drives a GPIO high or low on reboot | |
| +Load: gpio-poweroff,<param>=<val> | |
| +Params: gpiopin GPIO for signalling (default 26) | |
| + | |
| + active_low Set if the power control device requires a | |
| + high->low transition to trigger a power-down. | |
| + Note that this will require the support of a | |
| + custom dt-blob.bin to prevent a power-down | |
| + during the boot process, and that a reboot | |
| + will also cause the pin to go low. | |
| + | |
| + | |
| Name: hifiberry-amp | |
| Info: Configures the HifiBerry Amp and Amp+ audio cards | |
| Load: dtoverlay=hifiberry-amp | |
| diff --git a/arch/arm/boot/dts/overlays/gpio-poweroff-overlay.dts b/arch/arm/boot/dts/overlays/gpio-poweroff-overlay.dts | |
| new file mode 100644 | |
| index 0000000..ff8cb36 | |
| --- /dev/null | |
| +++ b/arch/arm/boot/dts/overlays/gpio-poweroff-overlay.dts | |
| @@ -0,0 +1,34 @@ | |
| +// Definitions for gpio-poweroff module | |
| +/dts-v1/; | |
| +/plugin/; | |
| + | |
| +/ { | |
| + compatible = "brcm,bcm2708"; | |
| + | |
| + fragment@0 { | |
| + target-path = "/"; | |
| + __overlay__ { | |
| + power_ctrl: power_ctrl { | |
| + compatible = "gpio-poweroff"; | |
| + gpios = <&gpio 26 0>; | |
| + force; | |
| + }; | |
| + }; | |
| + }; | |
| + | |
| + fragment@1 { | |
| + target = <&gpio>; | |
| + __overlay__ { | |
| + power_ctrl_pins: power_ctrl_pins { | |
| + brcm,pins = <26>; | |
| + brcm,function = <1>; // out | |
| + }; | |
| + }; | |
| + }; | |
| + | |
| + __overrides__ { | |
| + gpiopin = <&power_ctrl>,"gpios:4", | |
| + <&power_ctrl_pins>,"brcm,pins:0"; | |
| + active_low = <&power_ctrl>,"gpios:8"; | |
| + }; | |
| +}; | |
| diff --git a/drivers/power/reset/gpio-poweroff.c b/drivers/power/reset/gpio-poweroff.c | |
| index e5332f1..a7583b5 100644 | |
| --- a/drivers/power/reset/gpio-poweroff.c | |
| +++ b/drivers/power/reset/gpio-poweroff.c | |
| @@ -48,13 +48,18 @@ static void gpio_poweroff_do_poweroff(void) | |
| static int gpio_poweroff_probe(struct platform_device *pdev) | |
| { | |
| bool input = false; | |
| + bool force = false; | |
| - /* If a pm_power_off function has already been added, leave it alone */ | |
| - if (pm_power_off != NULL) { | |
| - dev_err(&pdev->dev, | |
| - "%s: pm_power_off function already registered", | |
| - __func__); | |
| - return -EBUSY; | |
| + force = of_property_read_bool(pdev->dev.of_node, "force"); | |
| + if (!force) { | |
| + /* If a pm_power_off function has already been added, | |
| + leave it alone */ | |
| + if (pm_power_off != NULL) { | |
| + dev_err(&pdev->dev, | |
| + "%s: pm_power_off function already registered", | |
| + __func__); | |
| + return -EBUSY; | |
| + } | |
| } | |
| reset_gpio = devm_gpiod_get(&pdev->dev, NULL); | |
| -- | |
| 1.9.1 | |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Has this been submitted to the Rasp PI kernel?
I was looking to use this on The Plum Geek Spirit Rover Robot, but would need it in the "standard kernel". The reason being is providing a 'custom' kernel for the robot would be a logistical nightmare. I feel that for some in the user community for the robot this would be a challenge.