diff options
Diffstat (limited to 'arch/x86/kernel/iris.c')
| -rw-r--r-- | arch/x86/kernel/iris.c | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/arch/x86/kernel/iris.c b/arch/x86/kernel/iris.c new file mode 100644 index 00000000000..1ba7f5ed8c9 --- /dev/null +++ b/arch/x86/kernel/iris.c @@ -0,0 +1,91 @@ +/* + * 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); |