linux_dsm_epyc7002/arch/x86/platform/iris/iris.c

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