91 lines
		
	
	
	
		
			2.8 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			91 lines
		
	
	
	
		
			2.8 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * Eurobraille/Iris power off support.
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 *
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 * Eurobraille's Iris machine is a PC with no APM or ACPI support.
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 * It is shutdown by a special I/O sequence which this module provides.
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 *
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 *  Copyright (C) Shérab <Sebastien.Hinderer@ens-lyon.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 as published by
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 * the Free Software Foundation ; either version 2 of the License, or
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 * (at your option) any later version.
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 *
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 * This program is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY ; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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 * GNU General Public License for more details.
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 *
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 * You should have received a copy of the GNU General Public License
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 * along with the program ; if not, write to the Free Software
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 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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 */
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#include <linux/moduleparam.h>
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/errno.h>
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#include <linux/delay.h>
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#include <linux/init.h>
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#include <linux/pm.h>
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#include <asm/io.h>
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#define IRIS_GIO_BASE		0x340
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#define IRIS_GIO_INPUT		IRIS_GIO_BASE
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#define IRIS_GIO_OUTPUT		(IRIS_GIO_BASE + 1)
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#define IRIS_GIO_PULSE		0x80 /* First byte to send */
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#define IRIS_GIO_REST		0x00 /* Second byte to send */
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#define IRIS_GIO_NODEV		0xff /* Likely not an Iris */
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Sébastien Hinderer <Sebastien.Hinderer@ens-lyon.org>");
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MODULE_DESCRIPTION("A power_off handler for Iris devices from EuroBraille");
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MODULE_SUPPORTED_DEVICE("Eurobraille/Iris");
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static int force;
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module_param(force, bool, 0);
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MODULE_PARM_DESC(force, "Set to one to force poweroff handler installation.");
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static void (*old_pm_power_off)(void);
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static void iris_power_off(void)
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{
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	outb(IRIS_GIO_PULSE, IRIS_GIO_OUTPUT);
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	msleep(850);
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	outb(IRIS_GIO_REST, IRIS_GIO_OUTPUT);
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}
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/*
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 * Before installing the power_off handler, try to make sure the OS is
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 * running on an Iris.  Since Iris does not support DMI, this is done
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 * by reading its input port and seeing whether the read value is
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 * meaningful.
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 */
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static int iris_init(void)
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{
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	unsigned char status;
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	if (force != 1) {
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		printk(KERN_ERR "The force parameter has not been set to 1 so the Iris poweroff handler will not be installed.\n");
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		return -ENODEV;
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	}
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	status = inb(IRIS_GIO_INPUT);
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	if (status == IRIS_GIO_NODEV) {
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		printk(KERN_ERR "This machine does not seem to be an Iris. Power_off handler not installed.\n");
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		return -ENODEV;
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	}
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	old_pm_power_off = pm_power_off;
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	pm_power_off = &iris_power_off;
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	printk(KERN_INFO "Iris power_off handler installed.\n");
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	return 0;
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}
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static void iris_exit(void)
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{
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	pm_power_off = old_pm_power_off;
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	printk(KERN_INFO "Iris power_off handler uninstalled.\n");
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}
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module_init(iris_init);
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module_exit(iris_exit);
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