forked from luck/tmp_suning_uos_patched
99b7623380
Setting ->owner as done currently (pde->owner = THIS_MODULE) is racy as correctly noted at bug #12454. Someone can lookup entry with NULL ->owner, thus not pinning enything, and release it later resulting in module refcount underflow. We can keep ->owner and supply it at registration time like ->proc_fops and ->data. But this leaves ->owner as easy-manipulative field (just one C assignment) and somebody will forget to unpin previous/pin current module when switching ->owner. ->proc_fops is declared as "const" which should give some thoughts. ->read_proc/->write_proc were just fixed to not require ->owner for protection. rmmod'ed directories will be empty and return "." and ".." -- no harm. And directories with tricky enough readdir and lookup shouldn't be modular. We definitely don't want such modular code. Removing ->owner will also make PDE smaller. So, let's nuke it. Kudos to Jeff Layton for reminding about this, let's say, oversight. http://bugzilla.kernel.org/show_bug.cgi?id=12454 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
372 lines
8.9 KiB
C
372 lines
8.9 KiB
C
/*
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* acpi_fan.c - ACPI Fan Driver ($Revision: 29 $)
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*
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* Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
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* Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
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*
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* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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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 (at
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* 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, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* 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 along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
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*
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* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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*/
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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/proc_fs.h>
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#include <linux/seq_file.h>
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#include <asm/uaccess.h>
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#include <linux/thermal.h>
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#include <acpi/acpi_bus.h>
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#include <acpi/acpi_drivers.h>
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#define ACPI_FAN_CLASS "fan"
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#define ACPI_FAN_FILE_STATE "state"
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#define _COMPONENT ACPI_FAN_COMPONENT
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ACPI_MODULE_NAME("fan");
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MODULE_AUTHOR("Paul Diefenbaugh");
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MODULE_DESCRIPTION("ACPI Fan Driver");
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MODULE_LICENSE("GPL");
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static int acpi_fan_add(struct acpi_device *device);
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static int acpi_fan_remove(struct acpi_device *device, int type);
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static int acpi_fan_suspend(struct acpi_device *device, pm_message_t state);
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static int acpi_fan_resume(struct acpi_device *device);
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static const struct acpi_device_id fan_device_ids[] = {
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{"PNP0C0B", 0},
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{"", 0},
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};
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MODULE_DEVICE_TABLE(acpi, fan_device_ids);
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static struct acpi_driver acpi_fan_driver = {
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.name = "fan",
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.class = ACPI_FAN_CLASS,
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.ids = fan_device_ids,
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.ops = {
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.add = acpi_fan_add,
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.remove = acpi_fan_remove,
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.suspend = acpi_fan_suspend,
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.resume = acpi_fan_resume,
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},
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};
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/* thermal cooling device callbacks */
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static int fan_get_max_state(struct thermal_cooling_device *cdev, char *buf)
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{
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/* ACPI fan device only support two states: ON/OFF */
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return sprintf(buf, "1\n");
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}
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static int fan_get_cur_state(struct thermal_cooling_device *cdev, char *buf)
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{
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struct acpi_device *device = cdev->devdata;
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int state;
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int result;
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if (!device)
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return -EINVAL;
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result = acpi_bus_get_power(device->handle, &state);
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if (result)
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return result;
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return sprintf(buf, "%s\n", state == ACPI_STATE_D3 ? "0" :
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(state == ACPI_STATE_D0 ? "1" : "unknown"));
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}
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static int
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fan_set_cur_state(struct thermal_cooling_device *cdev, unsigned int state)
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{
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struct acpi_device *device = cdev->devdata;
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int result;
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if (!device || (state != 0 && state != 1))
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return -EINVAL;
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result = acpi_bus_set_power(device->handle,
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state ? ACPI_STATE_D0 : ACPI_STATE_D3);
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return result;
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}
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static struct thermal_cooling_device_ops fan_cooling_ops = {
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.get_max_state = fan_get_max_state,
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.get_cur_state = fan_get_cur_state,
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.set_cur_state = fan_set_cur_state,
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};
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/* --------------------------------------------------------------------------
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FS Interface (/proc)
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-------------------------------------------------------------------------- */
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#ifdef CONFIG_ACPI_PROCFS
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static struct proc_dir_entry *acpi_fan_dir;
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static int acpi_fan_read_state(struct seq_file *seq, void *offset)
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{
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struct acpi_device *device = seq->private;
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int state = 0;
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if (device) {
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if (acpi_bus_get_power(device->handle, &state))
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seq_printf(seq, "status: ERROR\n");
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else
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seq_printf(seq, "status: %s\n",
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!state ? "on" : "off");
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}
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return 0;
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}
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static int acpi_fan_state_open_fs(struct inode *inode, struct file *file)
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{
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return single_open(file, acpi_fan_read_state, PDE(inode)->data);
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}
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static ssize_t
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acpi_fan_write_state(struct file *file, const char __user * buffer,
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size_t count, loff_t * ppos)
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{
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int result = 0;
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struct seq_file *m = file->private_data;
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struct acpi_device *device = m->private;
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char state_string[3] = { '\0' };
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if (count > sizeof(state_string) - 1)
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return -EINVAL;
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if (copy_from_user(state_string, buffer, count))
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return -EFAULT;
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state_string[count] = '\0';
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if ((state_string[0] < '0') || (state_string[0] > '3'))
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return -EINVAL;
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if (state_string[1] == '\n')
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state_string[1] = '\0';
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if (state_string[1] != '\0')
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return -EINVAL;
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result = acpi_bus_set_power(device->handle,
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simple_strtoul(state_string, NULL, 0));
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if (result)
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return result;
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return count;
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}
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static const struct file_operations acpi_fan_state_ops = {
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.open = acpi_fan_state_open_fs,
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.read = seq_read,
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.write = acpi_fan_write_state,
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.llseek = seq_lseek,
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.release = single_release,
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.owner = THIS_MODULE,
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};
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static int acpi_fan_add_fs(struct acpi_device *device)
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{
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struct proc_dir_entry *entry = NULL;
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if (!device)
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return -EINVAL;
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if (!acpi_device_dir(device)) {
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acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
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acpi_fan_dir);
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if (!acpi_device_dir(device))
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return -ENODEV;
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}
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/* 'status' [R/W] */
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entry = proc_create_data(ACPI_FAN_FILE_STATE,
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S_IFREG | S_IRUGO | S_IWUSR,
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acpi_device_dir(device),
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&acpi_fan_state_ops,
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device);
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if (!entry)
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return -ENODEV;
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return 0;
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}
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static int acpi_fan_remove_fs(struct acpi_device *device)
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{
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if (acpi_device_dir(device)) {
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remove_proc_entry(ACPI_FAN_FILE_STATE, acpi_device_dir(device));
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remove_proc_entry(acpi_device_bid(device), acpi_fan_dir);
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acpi_device_dir(device) = NULL;
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}
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return 0;
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}
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#else
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static int acpi_fan_add_fs(struct acpi_device *device)
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{
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return 0;
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}
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static int acpi_fan_remove_fs(struct acpi_device *device)
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{
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return 0;
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}
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#endif
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/* --------------------------------------------------------------------------
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Driver Interface
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-------------------------------------------------------------------------- */
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static int acpi_fan_add(struct acpi_device *device)
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{
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int result = 0;
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int state = 0;
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struct thermal_cooling_device *cdev;
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if (!device)
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return -EINVAL;
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strcpy(acpi_device_name(device), "Fan");
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strcpy(acpi_device_class(device), ACPI_FAN_CLASS);
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result = acpi_bus_get_power(device->handle, &state);
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if (result) {
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printk(KERN_ERR PREFIX "Reading power state\n");
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goto end;
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}
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device->flags.force_power_state = 1;
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acpi_bus_set_power(device->handle, state);
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device->flags.force_power_state = 0;
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cdev = thermal_cooling_device_register("Fan", device,
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&fan_cooling_ops);
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if (IS_ERR(cdev)) {
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result = PTR_ERR(cdev);
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goto end;
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}
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dev_info(&device->dev, "registered as cooling_device%d\n", cdev->id);
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device->driver_data = cdev;
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result = sysfs_create_link(&device->dev.kobj,
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&cdev->device.kobj,
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"thermal_cooling");
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if (result)
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dev_err(&device->dev, "Failed to create sysfs link "
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"'thermal_cooling'\n");
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result = sysfs_create_link(&cdev->device.kobj,
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&device->dev.kobj,
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"device");
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if (result)
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dev_err(&device->dev, "Failed to create sysfs link "
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"'device'\n");
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result = acpi_fan_add_fs(device);
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if (result)
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goto end;
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printk(KERN_INFO PREFIX "%s [%s] (%s)\n",
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acpi_device_name(device), acpi_device_bid(device),
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!device->power.state ? "on" : "off");
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end:
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return result;
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}
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static int acpi_fan_remove(struct acpi_device *device, int type)
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{
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struct thermal_cooling_device *cdev = acpi_driver_data(device);
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if (!device || !cdev)
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return -EINVAL;
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acpi_fan_remove_fs(device);
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sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
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sysfs_remove_link(&cdev->device.kobj, "device");
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thermal_cooling_device_unregister(cdev);
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return 0;
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}
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static int acpi_fan_suspend(struct acpi_device *device, pm_message_t state)
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{
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if (!device)
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return -EINVAL;
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acpi_bus_set_power(device->handle, ACPI_STATE_D0);
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return AE_OK;
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}
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static int acpi_fan_resume(struct acpi_device *device)
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{
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int result = 0;
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int power_state = 0;
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if (!device)
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return -EINVAL;
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result = acpi_bus_get_power(device->handle, &power_state);
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if (result) {
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printk(KERN_ERR PREFIX
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"Error reading fan power state\n");
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return result;
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}
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device->flags.force_power_state = 1;
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acpi_bus_set_power(device->handle, power_state);
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device->flags.force_power_state = 0;
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return result;
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}
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static int __init acpi_fan_init(void)
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{
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int result = 0;
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#ifdef CONFIG_ACPI_PROCFS
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acpi_fan_dir = proc_mkdir(ACPI_FAN_CLASS, acpi_root_dir);
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if (!acpi_fan_dir)
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return -ENODEV;
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#endif
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result = acpi_bus_register_driver(&acpi_fan_driver);
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if (result < 0) {
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remove_proc_entry(ACPI_FAN_CLASS, acpi_root_dir);
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return -ENODEV;
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}
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return 0;
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}
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static void __exit acpi_fan_exit(void)
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{
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acpi_bus_unregister_driver(&acpi_fan_driver);
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remove_proc_entry(ACPI_FAN_CLASS, acpi_root_dir);
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return;
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}
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module_init(acpi_fan_init);
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module_exit(acpi_fan_exit);
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