| /* |
| * arch/arm/mach-ixp4xx/nas100d-power.c |
| * |
| * NAS 100d Power/Reset driver |
| * |
| * Copyright (C) 2005 Tower Technologies |
| * |
| * based on nas100d-io.c |
| * Copyright (C) 2004 Karen Spearel |
| * |
| * Author: Alessandro Zummo <a.zummo@towertech.it> |
| * Maintainers: http://www.nslu2-linux.org/ |
| * |
| * 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/interrupt.h> |
| #include <linux/irq.h> |
| #include <linux/module.h> |
| #include <linux/reboot.h> |
| #include <linux/jiffies.h> |
| #include <linux/timer.h> |
| |
| #include <asm/gpio.h> |
| #include <asm/mach-types.h> |
| |
| /* This is used to make sure the power-button pusher is serious. The button |
| * must be held until the value of this counter reaches zero. |
| */ |
| static int power_button_countdown; |
| |
| /* Must hold the button down for at least this many counts to be processed */ |
| #define PBUTTON_HOLDDOWN_COUNT 4 /* 2 secs */ |
| |
| static void nas100d_power_handler(unsigned long data); |
| static DEFINE_TIMER(nas100d_power_timer, nas100d_power_handler, 0, 0); |
| |
| static void nas100d_power_handler(unsigned long data) |
| { |
| /* This routine is called twice per second to check the |
| * state of the power button. |
| */ |
| |
| if (gpio_get_value(NAS100D_PB_GPIO)) { |
| |
| /* IO Pin is 1 (button pushed) */ |
| if (power_button_countdown > 0) |
| power_button_countdown--; |
| |
| } else { |
| |
| /* Done on button release, to allow for auto-power-on mods. */ |
| if (power_button_countdown == 0) { |
| /* Signal init to do the ctrlaltdel action, |
| * this will bypass init if it hasn't started |
| * and do a kernel_restart. |
| */ |
| ctrl_alt_del(); |
| |
| /* Change the state of the power LED to "blink" */ |
| gpio_line_set(NAS100D_LED_PWR_GPIO, IXP4XX_GPIO_LOW); |
| } else { |
| power_button_countdown = PBUTTON_HOLDDOWN_COUNT; |
| } |
| } |
| |
| mod_timer(&nas100d_power_timer, jiffies + msecs_to_jiffies(500)); |
| } |
| |
| static irqreturn_t nas100d_reset_handler(int irq, void *dev_id) |
| { |
| /* This is the paper-clip reset, it shuts the machine down directly. */ |
| machine_power_off(); |
| |
| return IRQ_HANDLED; |
| } |
| |
| static int __init nas100d_power_init(void) |
| { |
| if (!(machine_is_nas100d())) |
| return 0; |
| |
| set_irq_type(gpio_to_irq(NAS100D_RB_GPIO), IRQT_LOW); |
| |
| if (request_irq(gpio_to_irq(NAS100D_RB_GPIO), &nas100d_reset_handler, |
| IRQF_DISABLED, "NAS100D reset button", NULL) < 0) { |
| |
| printk(KERN_DEBUG "Reset Button IRQ %d not available\n", |
| gpio_to_irq(NAS100D_RB_GPIO)); |
| |
| return -EIO; |
| } |
| |
| /* The power button on the Iomega NAS100d is on GPIO 14, but |
| * it cannot handle interrupts on that GPIO line. So we'll |
| * have to poll it with a kernel timer. |
| */ |
| |
| /* Make sure that the power button GPIO is set up as an input */ |
| gpio_line_config(NAS100D_PB_GPIO, IXP4XX_GPIO_IN); |
| |
| /* Set the initial value for the power button IRQ handler */ |
| power_button_countdown = PBUTTON_HOLDDOWN_COUNT; |
| |
| mod_timer(&nas100d_power_timer, jiffies + msecs_to_jiffies(500)); |
| |
| return 0; |
| } |
| |
| static void __exit nas100d_power_exit(void) |
| { |
| if (!(machine_is_nas100d())) |
| return; |
| |
| del_timer_sync(&nas100d_power_timer); |
| |
| free_irq(gpio_to_irq(NAS100D_RB_GPIO), NULL); |
| } |
| |
| module_init(nas100d_power_init); |
| module_exit(nas100d_power_exit); |
| |
| MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>"); |
| MODULE_DESCRIPTION("NAS100D Power/Reset driver"); |
| MODULE_LICENSE("GPL"); |