| Shérab | 82148d1 | 2010-09-25 06:06:57 +0200 | [diff] [blame] | 1 | /* |
| 2 | * Eurobraille/Iris power off support. |
| 3 | * |
| 4 | * Eurobraille's Iris machine is a PC with no APM or ACPI support. |
| 5 | * It is shutdown by a special I/O sequence which this module provides. |
| 6 | * |
| 7 | * Copyright (C) Shérab <Sebastien.Hinderer@ens-lyon.org> |
| 8 | * |
| 9 | * This program is free software ; you can redistribute it and/or modify |
| 10 | * it under the terms of the GNU General Public License as published by |
| 11 | * the Free Software Foundation ; either version 2 of the License, or |
| 12 | * (at your option) any later version. |
| 13 | * |
| 14 | * This program is distributed in the hope that it will be useful, |
| 15 | * but WITHOUT ANY WARRANTY ; without even the implied warranty of |
| 16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 17 | * GNU General Public License for more details. |
| 18 | * |
| 19 | * You should have received a copy of the GNU General Public License |
| 20 | * along with the program ; if not, write to the Free Software |
| 21 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
| 22 | */ |
| 23 | |
| 24 | #include <linux/moduleparam.h> |
| 25 | #include <linux/module.h> |
| 26 | #include <linux/kernel.h> |
| 27 | #include <linux/errno.h> |
| 28 | #include <linux/delay.h> |
| 29 | #include <linux/init.h> |
| 30 | #include <linux/pm.h> |
| 31 | #include <asm/io.h> |
| 32 | |
| 33 | #define IRIS_GIO_BASE 0x340 |
| 34 | #define IRIS_GIO_INPUT IRIS_GIO_BASE |
| 35 | #define IRIS_GIO_OUTPUT (IRIS_GIO_BASE + 1) |
| 36 | #define IRIS_GIO_PULSE 0x80 /* First byte to send */ |
| 37 | #define IRIS_GIO_REST 0x00 /* Second byte to send */ |
| 38 | #define IRIS_GIO_NODEV 0xff /* Likely not an Iris */ |
| 39 | |
| 40 | MODULE_LICENSE("GPL"); |
| 41 | MODULE_AUTHOR("Sébastien Hinderer <Sebastien.Hinderer@ens-lyon.org>"); |
| 42 | MODULE_DESCRIPTION("A power_off handler for Iris devices from EuroBraille"); |
| 43 | MODULE_SUPPORTED_DEVICE("Eurobraille/Iris"); |
| 44 | |
| Rusty Russell | 476bc00 | 2012-01-13 09:32:18 +1030 | [diff] [blame] | 45 | static bool force; |
| Shérab | 82148d1 | 2010-09-25 06:06:57 +0200 | [diff] [blame] | 46 | |
| 47 | module_param(force, bool, 0); |
| 48 | MODULE_PARM_DESC(force, "Set to one to force poweroff handler installation."); |
| 49 | |
| 50 | static void (*old_pm_power_off)(void); |
| 51 | |
| 52 | static void iris_power_off(void) |
| 53 | { |
| 54 | outb(IRIS_GIO_PULSE, IRIS_GIO_OUTPUT); |
| 55 | msleep(850); |
| 56 | outb(IRIS_GIO_REST, IRIS_GIO_OUTPUT); |
| 57 | } |
| 58 | |
| 59 | /* |
| 60 | * Before installing the power_off handler, try to make sure the OS is |
| 61 | * running on an Iris. Since Iris does not support DMI, this is done |
| 62 | * by reading its input port and seeing whether the read value is |
| 63 | * meaningful. |
| 64 | */ |
| 65 | static int iris_init(void) |
| 66 | { |
| 67 | unsigned char status; |
| 68 | if (force != 1) { |
| 69 | printk(KERN_ERR "The force parameter has not been set to 1 so the Iris poweroff handler will not be installed.\n"); |
| 70 | return -ENODEV; |
| 71 | } |
| 72 | status = inb(IRIS_GIO_INPUT); |
| 73 | if (status == IRIS_GIO_NODEV) { |
| 74 | printk(KERN_ERR "This machine does not seem to be an Iris. Power_off handler not installed.\n"); |
| 75 | return -ENODEV; |
| 76 | } |
| 77 | old_pm_power_off = pm_power_off; |
| 78 | pm_power_off = &iris_power_off; |
| 79 | printk(KERN_INFO "Iris power_off handler installed.\n"); |
| 80 | |
| 81 | return 0; |
| 82 | } |
| 83 | |
| 84 | static void iris_exit(void) |
| 85 | { |
| 86 | pm_power_off = old_pm_power_off; |
| 87 | printk(KERN_INFO "Iris power_off handler uninstalled.\n"); |
| 88 | } |
| 89 | |
| 90 | module_init(iris_init); |
| 91 | module_exit(iris_exit); |