130 lines
3.3 KiB
C
130 lines
3.3 KiB
C
/*
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* arch/arm/mach-ixp4xx/dsmg600-power.c
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*
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* DSM-G600 Power/Reset driver
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* Author: Michael Westerhof <mwester@dls.net>
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*
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* Based on nslu2-power.c
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* Copyright (C) 2005 Tower Technologies
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* Author: Alessandro Zummo <a.zummo@towertech.it>
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*
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* which was based on nslu2-io.c
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* Copyright (C) 2004 Karen Spearel
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*
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* Maintainers: http://www.nslu2-linux.org/
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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*/
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#include <linux/module.h>
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#include <linux/reboot.h>
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#include <linux/interrupt.h>
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#include <linux/irq.h>
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#include <linux/jiffies.h>
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#include <linux/timer.h>
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#include <asm/gpio.h>
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#include <asm/mach-types.h>
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/* This is used to make sure the power-button pusher is serious. The button
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* must be held until the value of this counter reaches zero.
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*/
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static int power_button_countdown;
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/* Must hold the button down for at least this many counts to be processed */
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#define PBUTTON_HOLDDOWN_COUNT 4 /* 2 secs */
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static void dsmg600_power_handler(unsigned long data);
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static DEFINE_TIMER(dsmg600_power_timer, dsmg600_power_handler, 0, 0);
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static void dsmg600_power_handler(unsigned long data)
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{
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/* This routine is called twice per second to check the
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* state of the power button.
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*/
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if (gpio_get_value(DSMG600_PB_GPIO)) {
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/* IO Pin is 1 (button pushed) */
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if (power_button_countdown > 0)
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power_button_countdown--;
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} else {
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/* Done on button release, to allow for auto-power-on mods. */
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if (power_button_countdown == 0) {
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/* Signal init to do the ctrlaltdel action,
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* this will bypass init if it hasn't started
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* and do a kernel_restart.
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*/
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ctrl_alt_del();
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/* Change the state of the power LED to "blink" */
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gpio_line_set(DSMG600_LED_PWR_GPIO, IXP4XX_GPIO_LOW);
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} else {
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power_button_countdown = PBUTTON_HOLDDOWN_COUNT;
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}
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}
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mod_timer(&dsmg600_power_timer, jiffies + msecs_to_jiffies(500));
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}
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static irqreturn_t dsmg600_reset_handler(int irq, void *dev_id)
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{
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/* This is the paper-clip reset, it shuts the machine down directly. */
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machine_power_off();
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return IRQ_HANDLED;
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}
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static int __init dsmg600_power_init(void)
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{
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if (!(machine_is_dsmg600()))
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return 0;
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if (request_irq(gpio_to_irq(DSMG600_RB_GPIO), &dsmg600_reset_handler,
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IRQF_DISABLED | IRQF_TRIGGER_LOW, "DSM-G600 reset button",
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NULL) < 0) {
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printk(KERN_DEBUG "Reset Button IRQ %d not available\n",
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gpio_to_irq(DSMG600_RB_GPIO));
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return -EIO;
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}
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/* The power button on the D-Link DSM-G600 is on GPIO 15, but
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* it cannot handle interrupts on that GPIO line. So we'll
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* have to poll it with a kernel timer.
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*/
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/* Make sure that the power button GPIO is set up as an input */
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gpio_line_config(DSMG600_PB_GPIO, IXP4XX_GPIO_IN);
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/* Set the initial value for the power button IRQ handler */
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power_button_countdown = PBUTTON_HOLDDOWN_COUNT;
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mod_timer(&dsmg600_power_timer, jiffies + msecs_to_jiffies(500));
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return 0;
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}
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static void __exit dsmg600_power_exit(void)
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{
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if (!(machine_is_dsmg600()))
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return;
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del_timer_sync(&dsmg600_power_timer);
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free_irq(gpio_to_irq(DSMG600_RB_GPIO), NULL);
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}
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module_init(dsmg600_power_init);
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module_exit(dsmg600_power_exit);
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MODULE_AUTHOR("Michael Westerhof <mwester@dls.net>");
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MODULE_DESCRIPTION("DSM-G600 Power/Reset driver");
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MODULE_LICENSE("GPL");
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