[PATCH 3/4] Power: Reset: Power off by restarting
From: andrew@lunn.ch (Andrew Lunn)
Date: 2012-12-28 12:25:11
Subsystem:
open firmware and flattened device tree bindings, system reset/shutdown drivers, the rest · Maintainers:
Rob Herring, Krzysztof Kozlowski, Conor Dooley, Sebastian Reichel, Linus Torvalds
Some devices, Buffalo Linkstation LS-XHL and LS-CHLv2 for example, power-off by restarting to letting u-boot hold the SoC until the user presses a key. Add a generic driver to implement this. It binds a function to pm_power_off, which calls arm_pm_restart. Signed-off-by: Andrew Lunn <andrew@lunn.ch> --- .../bindings/power_supply/restart-poweroff.txt | 9 +++ drivers/power/reset/Kconfig | 8 +++ drivers/power/reset/Makefile | 1 + drivers/power/reset/restart-poweroff.c | 67 ++++++++++++++++++++ 4 files changed, 85 insertions(+) create mode 100644 Documentation/devicetree/bindings/power_supply/restart-poweroff.txt create mode 100644 drivers/power/reset/restart-poweroff.c
diff --git a/Documentation/devicetree/bindings/power_supply/restart-poweroff.txt b/Documentation/devicetree/bindings/power_supply/restart-poweroff.txt
new file mode 100644
index 0000000..e4f1660
--- /dev/null
+++ b/Documentation/devicetree/bindings/power_supply/restart-poweroff.txt@@ -0,0 +1,9 @@ +* Restart Power Off + +Buffalo Linkstation LS-XHL and LS-CHLv2, and other devices power off +by restarting and letting u-boot keep hold of the machine until the +user presses a button. + +Required Properties: +- compatible: Should be "restart-poweroff" +
diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
index 6453aac..1ae65b8 100644
--- a/drivers/power/reset/Kconfig
+++ b/drivers/power/reset/Kconfig@@ -22,3 +22,11 @@ config POWER_RESET_QNAP commands to the microcontroller which controls the main power. Say Y if you have a QNAP NAS. + +config POWER_RESET_RESTART + bool "Restart power-off driver" + depends on ARM + help + Some boards don't actually have the ability to power off. + Instead they restart, and u-boot holds the SoC until the + user presses a key. u-boot then boots into Linux.
diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile
index c4d3b2d..0f317f5 100644
--- a/drivers/power/reset/Makefile
+++ b/drivers/power/reset/Makefile@@ -1,2 +1,3 @@ obj-$(CONFIG_POWER_RESET_GPIO) += gpio-poweroff.o obj-$(CONFIG_POWER_RESET_QNAP) += qnap-poweroff.o +obj-$(CONFIG_POWER_RESET_RESTART) += restart-poweroff.o
\ No newline at end of file
diff --git a/drivers/power/reset/restart-poweroff.c b/drivers/power/reset/restart-poweroff.c
new file mode 100644
index 0000000..79b1a2e
--- /dev/null
+++ b/drivers/power/reset/restart-poweroff.c@@ -0,0 +1,67 @@ +/* + * Power off by restarting and let u-boot keep hold of the machine + * until the user presses a button for example. + * + * Andrew Lunn <andrew@lunn.ch> + * + * Copyright (C) 2012 Andrew Lunn + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + */ +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/platform_device.h> +#include <asm/system_misc.h> +#include <linux/of_platform.h> +#include <linux/module.h> + +static void restart_poweroff_do_poweroff(void) +{ + arm_pm_restart('h', NULL); +} + +static int __devinit restart_poweroff_probe(struct platform_device *pdev) +{ + /* If a pm_power_off function has already been added, leave it alone */ + if (pm_power_off != NULL) { + dev_err(&pdev->dev, + "pm_power_off function already registered"); + return -EBUSY; + } + + pm_power_off = &restart_poweroff_do_poweroff; + return 0; +} + +static int __devexit restart_poweroff_remove(struct platform_device *pdev) +{ + if (pm_power_off == &restart_poweroff_do_poweroff) + pm_power_off = NULL; + + return 0; +} + +static const struct of_device_id of_restart_poweroff_match[] = { + { .compatible = "restart-poweroff", }, + {}, +}; + +static struct platform_driver restart_poweroff_driver = { + .probe = restart_poweroff_probe, + .remove = __devexit_p(restart_poweroff_remove), + .driver = { + .name = "poweroff-restart", + .owner = THIS_MODULE, + .of_match_table = of_restart_poweroff_match, + }, +}; + +module_platform_driver(restart_poweroff_driver); + +MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch"); +MODULE_DESCRIPTION("restart poweroff driver"); +MODULE_LICENSE("GPLv2"); +MODULE_ALIAS("platform:poweroff-restart");
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1.7.10.4