drivers/parisc/power.c

2  * linux/drivers/parisc/power.c
3  * HP PARISC soft power switch support driver
5  * Copyright (c) 2001-2007 Helge Deller <deller@gmx.de>
33  *  Support of the soft power switch button may be enabled or disabled at
34  *  runtime through the "/proc/sys/kernel/power" procfs entry.
53 /* how often should the power button be polled ? */
56 /* how long does the power button needs to be down until we react ? */
89 	/* wait until the button was pressed for 1 second */  in process_shutdown()
105 /* main power switch task struct */
108 /* filename in /proc which can be used to enable/disable the power switch */
109 #define SYSCTL_FILENAME	"sys/kernel/power"
111 /* soft power switch enabled/disabled */
114 /* main kernel thread worker. It polls the button state */
131 			 * Non-Gecko-style machines:  in kpowerswd()
132 			 * Check the power switch status which is read from the  in kpowerswd()
134 			 * Bit 31 ("the lowest bit) is the status of the power switch.  in kpowerswd()
135 			 * This bit is "1" if the button is NOT pressed.  in kpowerswd()
141 			 * the power switch status is stored in Bit 0 ("the highest bit")  in kpowerswd()
144 			 * the button has been released again.  in kpowerswd()
181  * executed any longer. This function then re-enables the
182  * soft-power switch and allows the user to switch off the system
187 	/* re-enable the soft-power switch */  in parisc_panic_event()
208 	/* enable the soft power switch if possible */  in power_init()
213 		soft_power_reg = -1UL;  in power_init()
216 	case 0:		printk(KERN_INFO DRIVER_NAME ": Gecko-style soft power switch enabled.\n");  in power_init()
219 	case -1UL:	printk(KERN_INFO DRIVER_NAME ": Soft power switch support not available.\n");  in power_init()
220 			return -ENODEV;  in power_init()
222 	default:	printk(KERN_INFO DRIVER_NAME ": Soft power switch at 0x%08lx enabled.\n",  in power_init()
230 		return -EIO;  in power_init()
255 MODULE_DESCRIPTION("Soft power switch driver");