/*
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* pvpanic.c - pvpanic Device Support
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*
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* Copyright (C) 2013 Fujitsu.
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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 this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/types.h>
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#include <linux/acpi.h>
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MODULE_AUTHOR("Hu Tao <hutao@cn.fujitsu.com>");
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MODULE_DESCRIPTION("pvpanic device driver");
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MODULE_LICENSE("GPL");
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static int pvpanic_add(struct acpi_device *device);
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static int pvpanic_remove(struct acpi_device *device);
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static const struct acpi_device_id pvpanic_device_ids[] = {
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{ "QEMU0001", 0 },
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{ "", 0 },
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};
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MODULE_DEVICE_TABLE(acpi, pvpanic_device_ids);
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#define PVPANIC_PANICKED (1 << 0)
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static u16 port;
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static struct acpi_driver pvpanic_driver = {
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.name = "pvpanic",
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.class = "QEMU",
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.ids = pvpanic_device_ids,
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.ops = {
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.add = pvpanic_add,
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.remove = pvpanic_remove,
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},
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.owner = THIS_MODULE,
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};
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static void
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pvpanic_send_event(unsigned int event)
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{
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outb(event, port);
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}
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static int
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pvpanic_panic_notify(struct notifier_block *nb, unsigned long code,
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void *unused)
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{
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pvpanic_send_event(PVPANIC_PANICKED);
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return NOTIFY_DONE;
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}
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static struct notifier_block pvpanic_panic_nb = {
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.notifier_call = pvpanic_panic_notify,
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.priority = 1, /* let this called before broken drm_fb_helper */
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};
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static acpi_status
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pvpanic_walk_resources(struct acpi_resource *res, void *context)
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{
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switch (res->type) {
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case ACPI_RESOURCE_TYPE_END_TAG:
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return AE_OK;
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case ACPI_RESOURCE_TYPE_IO:
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port = res->data.io.minimum;
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return AE_OK;
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default:
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return AE_ERROR;
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}
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}
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static int pvpanic_add(struct acpi_device *device)
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{
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int ret;
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ret = acpi_bus_get_status(device);
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if (ret < 0)
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return ret;
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if (!device->status.enabled || !device->status.functional)
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return -ENODEV;
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acpi_walk_resources(device->handle, METHOD_NAME__CRS,
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pvpanic_walk_resources, NULL);
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if (!port)
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return -ENODEV;
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atomic_notifier_chain_register(&panic_notifier_list,
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&pvpanic_panic_nb);
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return 0;
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}
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static int pvpanic_remove(struct acpi_device *device)
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{
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atomic_notifier_chain_unregister(&panic_notifier_list,
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&pvpanic_panic_nb);
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return 0;
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}
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module_acpi_driver(pvpanic_driver);
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