// SPDX-License-Identifier: GPL-2.0-or-later
|
/*
|
* 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>
|
*/
|
|
#include <linux/moduleparam.h>
|
#include <linux/module.h>
|
#include <linux/platform_device.h>
|
#include <linux/kernel.h>
|
#include <linux/errno.h>
|
#include <linux/delay.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 bool 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_probe(struct platform_device *pdev)
|
{
|
unsigned char 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 int iris_remove(struct platform_device *pdev)
|
{
|
pm_power_off = old_pm_power_off;
|
printk(KERN_INFO "Iris power_off handler uninstalled.\n");
|
return 0;
|
}
|
|
static struct platform_driver iris_driver = {
|
.driver = {
|
.name = "iris",
|
},
|
.probe = iris_probe,
|
.remove = iris_remove,
|
};
|
|
static struct resource iris_resources[] = {
|
{
|
.start = IRIS_GIO_BASE,
|
.end = IRIS_GIO_OUTPUT,
|
.flags = IORESOURCE_IO,
|
.name = "address"
|
}
|
};
|
|
static struct platform_device *iris_device;
|
|
static int iris_init(void)
|
{
|
int ret;
|
if (force != 1) {
|
printk(KERN_ERR "The force parameter has not been set to 1."
|
" The Iris poweroff handler will not be installed.\n");
|
return -ENODEV;
|
}
|
ret = platform_driver_register(&iris_driver);
|
if (ret < 0) {
|
printk(KERN_ERR "Failed to register iris platform driver: %d\n",
|
ret);
|
return ret;
|
}
|
iris_device = platform_device_register_simple("iris", (-1),
|
iris_resources, ARRAY_SIZE(iris_resources));
|
if (IS_ERR(iris_device)) {
|
printk(KERN_ERR "Failed to register iris platform device\n");
|
platform_driver_unregister(&iris_driver);
|
return PTR_ERR(iris_device);
|
}
|
return 0;
|
}
|
|
static void iris_exit(void)
|
{
|
platform_device_unregister(iris_device);
|
platform_driver_unregister(&iris_driver);
|
}
|
|
module_init(iris_init);
|
module_exit(iris_exit);
|
