linux/drivers/acpi/button.c
Alexey Dobriyan 99b7623380 proc 2/2: remove struct proc_dir_entry::owner
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>
2009-03-31 01:14:44 +04:00

547 lines
15 KiB
C

/*
* acpi_button.c - ACPI Button Driver ($Revision: 30 $)
*
* Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
* Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
* 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 this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/input.h>
#include <acpi/acpi_bus.h>
#include <acpi/acpi_drivers.h>
#define ACPI_BUTTON_CLASS "button"
#define ACPI_BUTTON_FILE_INFO "info"
#define ACPI_BUTTON_FILE_STATE "state"
#define ACPI_BUTTON_TYPE_UNKNOWN 0x00
#define ACPI_BUTTON_NOTIFY_STATUS 0x80
#define ACPI_BUTTON_SUBCLASS_POWER "power"
#define ACPI_BUTTON_HID_POWER "PNP0C0C"
#define ACPI_BUTTON_DEVICE_NAME_POWER "Power Button (CM)"
#define ACPI_BUTTON_DEVICE_NAME_POWERF "Power Button (FF)"
#define ACPI_BUTTON_TYPE_POWER 0x01
#define ACPI_BUTTON_TYPE_POWERF 0x02
#define ACPI_BUTTON_SUBCLASS_SLEEP "sleep"
#define ACPI_BUTTON_HID_SLEEP "PNP0C0E"
#define ACPI_BUTTON_DEVICE_NAME_SLEEP "Sleep Button (CM)"
#define ACPI_BUTTON_DEVICE_NAME_SLEEPF "Sleep Button (FF)"
#define ACPI_BUTTON_TYPE_SLEEP 0x03
#define ACPI_BUTTON_TYPE_SLEEPF 0x04
#define ACPI_BUTTON_SUBCLASS_LID "lid"
#define ACPI_BUTTON_HID_LID "PNP0C0D"
#define ACPI_BUTTON_DEVICE_NAME_LID "Lid Switch"
#define ACPI_BUTTON_TYPE_LID 0x05
#define _COMPONENT ACPI_BUTTON_COMPONENT
ACPI_MODULE_NAME("button");
MODULE_AUTHOR("Paul Diefenbaugh");
MODULE_DESCRIPTION("ACPI Button Driver");
MODULE_LICENSE("GPL");
static const struct acpi_device_id button_device_ids[] = {
{ACPI_BUTTON_HID_LID, 0},
{ACPI_BUTTON_HID_SLEEP, 0},
{ACPI_BUTTON_HID_SLEEPF, 0},
{ACPI_BUTTON_HID_POWER, 0},
{ACPI_BUTTON_HID_POWERF, 0},
{"", 0},
};
MODULE_DEVICE_TABLE(acpi, button_device_ids);
static int acpi_button_add(struct acpi_device *device);
static int acpi_button_remove(struct acpi_device *device, int type);
static int acpi_button_resume(struct acpi_device *device);
static int acpi_button_info_open_fs(struct inode *inode, struct file *file);
static int acpi_button_state_open_fs(struct inode *inode, struct file *file);
static struct acpi_driver acpi_button_driver = {
.name = "button",
.class = ACPI_BUTTON_CLASS,
.ids = button_device_ids,
.ops = {
.add = acpi_button_add,
.resume = acpi_button_resume,
.remove = acpi_button_remove,
},
};
struct acpi_button {
struct acpi_device *device; /* Fixed button kludge */
unsigned int type;
struct input_dev *input;
char phys[32]; /* for input device */
unsigned long pushed;
};
static const struct file_operations acpi_button_info_fops = {
.owner = THIS_MODULE,
.open = acpi_button_info_open_fs,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
static const struct file_operations acpi_button_state_fops = {
.owner = THIS_MODULE,
.open = acpi_button_state_open_fs,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
/* --------------------------------------------------------------------------
FS Interface (/proc)
-------------------------------------------------------------------------- */
static struct proc_dir_entry *acpi_button_dir;
static int acpi_button_info_seq_show(struct seq_file *seq, void *offset)
{
struct acpi_button *button = seq->private;
if (!button || !button->device)
return 0;
seq_printf(seq, "type: %s\n",
acpi_device_name(button->device));
return 0;
}
static int acpi_button_info_open_fs(struct inode *inode, struct file *file)
{
return single_open(file, acpi_button_info_seq_show, PDE(inode)->data);
}
static int acpi_button_state_seq_show(struct seq_file *seq, void *offset)
{
struct acpi_button *button = seq->private;
acpi_status status;
unsigned long long state;
if (!button || !button->device)
return 0;
status = acpi_evaluate_integer(button->device->handle, "_LID", NULL, &state);
seq_printf(seq, "state: %s\n",
ACPI_FAILURE(status) ? "unsupported" :
(state ? "open" : "closed"));
return 0;
}
static int acpi_button_state_open_fs(struct inode *inode, struct file *file)
{
return single_open(file, acpi_button_state_seq_show, PDE(inode)->data);
}
static struct proc_dir_entry *acpi_power_dir;
static struct proc_dir_entry *acpi_sleep_dir;
static struct proc_dir_entry *acpi_lid_dir;
static int acpi_button_add_fs(struct acpi_device *device)
{
struct proc_dir_entry *entry = NULL;
struct acpi_button *button;
if (!device || !acpi_driver_data(device))
return -EINVAL;
button = acpi_driver_data(device);
switch (button->type) {
case ACPI_BUTTON_TYPE_POWER:
case ACPI_BUTTON_TYPE_POWERF:
if (!acpi_power_dir)
acpi_power_dir = proc_mkdir(ACPI_BUTTON_SUBCLASS_POWER,
acpi_button_dir);
entry = acpi_power_dir;
break;
case ACPI_BUTTON_TYPE_SLEEP:
case ACPI_BUTTON_TYPE_SLEEPF:
if (!acpi_sleep_dir)
acpi_sleep_dir = proc_mkdir(ACPI_BUTTON_SUBCLASS_SLEEP,
acpi_button_dir);
entry = acpi_sleep_dir;
break;
case ACPI_BUTTON_TYPE_LID:
if (!acpi_lid_dir)
acpi_lid_dir = proc_mkdir(ACPI_BUTTON_SUBCLASS_LID,
acpi_button_dir);
entry = acpi_lid_dir;
break;
}
if (!entry)
return -ENODEV;
acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device), entry);
if (!acpi_device_dir(device))
return -ENODEV;
/* 'info' [R] */
entry = proc_create_data(ACPI_BUTTON_FILE_INFO,
S_IRUGO, acpi_device_dir(device),
&acpi_button_info_fops,
acpi_driver_data(device));
if (!entry)
return -ENODEV;
/* show lid state [R] */
if (button->type == ACPI_BUTTON_TYPE_LID) {
entry = proc_create_data(ACPI_BUTTON_FILE_STATE,
S_IRUGO, acpi_device_dir(device),
&acpi_button_state_fops,
acpi_driver_data(device));
if (!entry)
return -ENODEV;
}
return 0;
}
static int acpi_button_remove_fs(struct acpi_device *device)
{
struct acpi_button *button = acpi_driver_data(device);
if (acpi_device_dir(device)) {
if (button->type == ACPI_BUTTON_TYPE_LID)
remove_proc_entry(ACPI_BUTTON_FILE_STATE,
acpi_device_dir(device));
remove_proc_entry(ACPI_BUTTON_FILE_INFO,
acpi_device_dir(device));
remove_proc_entry(acpi_device_bid(device),
acpi_device_dir(device)->parent);
acpi_device_dir(device) = NULL;
}
return 0;
}
/* --------------------------------------------------------------------------
Driver Interface
-------------------------------------------------------------------------- */
static int acpi_lid_send_state(struct acpi_button *button)
{
unsigned long long state;
acpi_status status;
status = acpi_evaluate_integer(button->device->handle, "_LID", NULL,
&state);
if (ACPI_FAILURE(status))
return -ENODEV;
/* input layer checks if event is redundant */
input_report_switch(button->input, SW_LID, !state);
input_sync(button->input);
return 0;
}
static void acpi_button_notify(acpi_handle handle, u32 event, void *data)
{
struct acpi_button *button = data;
struct input_dev *input;
if (!button || !button->device)
return;
switch (event) {
case ACPI_BUTTON_NOTIFY_STATUS:
input = button->input;
if (button->type == ACPI_BUTTON_TYPE_LID) {
acpi_lid_send_state(button);
} else {
int keycode = test_bit(KEY_SLEEP, input->keybit) ?
KEY_SLEEP : KEY_POWER;
input_report_key(input, keycode, 1);
input_sync(input);
input_report_key(input, keycode, 0);
input_sync(input);
}
acpi_bus_generate_proc_event(button->device, event,
++button->pushed);
break;
default:
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Unsupported event [0x%x]\n", event));
break;
}
return;
}
static acpi_status acpi_button_notify_fixed(void *data)
{
struct acpi_button *button = data;
if (!button)
return AE_BAD_PARAMETER;
acpi_button_notify(button->device->handle, ACPI_BUTTON_NOTIFY_STATUS, button);
return AE_OK;
}
static int acpi_button_install_notify_handlers(struct acpi_button *button)
{
acpi_status status;
switch (button->type) {
case ACPI_BUTTON_TYPE_POWERF:
status =
acpi_install_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
acpi_button_notify_fixed,
button);
break;
case ACPI_BUTTON_TYPE_SLEEPF:
status =
acpi_install_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
acpi_button_notify_fixed,
button);
break;
default:
status = acpi_install_notify_handler(button->device->handle,
ACPI_DEVICE_NOTIFY,
acpi_button_notify,
button);
break;
}
return ACPI_FAILURE(status) ? -ENODEV : 0;
}
static int acpi_button_resume(struct acpi_device *device)
{
struct acpi_button *button;
if (!device)
return -EINVAL;
button = acpi_driver_data(device);
if (button && button->type == ACPI_BUTTON_TYPE_LID)
return acpi_lid_send_state(button);
return 0;
}
static void acpi_button_remove_notify_handlers(struct acpi_button *button)
{
switch (button->type) {
case ACPI_BUTTON_TYPE_POWERF:
acpi_remove_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
acpi_button_notify_fixed);
break;
case ACPI_BUTTON_TYPE_SLEEPF:
acpi_remove_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
acpi_button_notify_fixed);
break;
default:
acpi_remove_notify_handler(button->device->handle,
ACPI_DEVICE_NOTIFY,
acpi_button_notify);
break;
}
}
static int acpi_button_add(struct acpi_device *device)
{
int error;
struct acpi_button *button;
struct input_dev *input;
if (!device)
return -EINVAL;
button = kzalloc(sizeof(struct acpi_button), GFP_KERNEL);
if (!button)
return -ENOMEM;
button->device = device;
device->driver_data = button;
button->input = input = input_allocate_device();
if (!input) {
error = -ENOMEM;
goto err_free_button;
}
/*
* Determine the button type (via hid), as fixed-feature buttons
* need to be handled a bit differently than generic-space.
*/
if (!strcmp(acpi_device_hid(device), ACPI_BUTTON_HID_POWER)) {
button->type = ACPI_BUTTON_TYPE_POWER;
strcpy(acpi_device_name(device), ACPI_BUTTON_DEVICE_NAME_POWER);
sprintf(acpi_device_class(device), "%s/%s",
ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_POWER);
} else if (!strcmp(acpi_device_hid(device), ACPI_BUTTON_HID_POWERF)) {
button->type = ACPI_BUTTON_TYPE_POWERF;
strcpy(acpi_device_name(device),
ACPI_BUTTON_DEVICE_NAME_POWERF);
sprintf(acpi_device_class(device), "%s/%s",
ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_POWER);
} else if (!strcmp(acpi_device_hid(device), ACPI_BUTTON_HID_SLEEP)) {
button->type = ACPI_BUTTON_TYPE_SLEEP;
strcpy(acpi_device_name(device), ACPI_BUTTON_DEVICE_NAME_SLEEP);
sprintf(acpi_device_class(device), "%s/%s",
ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_SLEEP);
} else if (!strcmp(acpi_device_hid(device), ACPI_BUTTON_HID_SLEEPF)) {
button->type = ACPI_BUTTON_TYPE_SLEEPF;
strcpy(acpi_device_name(device),
ACPI_BUTTON_DEVICE_NAME_SLEEPF);
sprintf(acpi_device_class(device), "%s/%s",
ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_SLEEP);
} else if (!strcmp(acpi_device_hid(device), ACPI_BUTTON_HID_LID)) {
button->type = ACPI_BUTTON_TYPE_LID;
strcpy(acpi_device_name(device), ACPI_BUTTON_DEVICE_NAME_LID);
sprintf(acpi_device_class(device), "%s/%s",
ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_LID);
} else {
printk(KERN_ERR PREFIX "Unsupported hid [%s]\n",
acpi_device_hid(device));
error = -ENODEV;
goto err_free_input;
}
error = acpi_button_add_fs(device);
if (error)
goto err_free_input;
error = acpi_button_install_notify_handlers(button);
if (error)
goto err_remove_fs;
snprintf(button->phys, sizeof(button->phys),
"%s/button/input0", acpi_device_hid(device));
input->name = acpi_device_name(device);
input->phys = button->phys;
input->id.bustype = BUS_HOST;
input->id.product = button->type;
input->dev.parent = &device->dev;
switch (button->type) {
case ACPI_BUTTON_TYPE_POWER:
case ACPI_BUTTON_TYPE_POWERF:
input->evbit[0] = BIT_MASK(EV_KEY);
set_bit(KEY_POWER, input->keybit);
break;
case ACPI_BUTTON_TYPE_SLEEP:
case ACPI_BUTTON_TYPE_SLEEPF:
input->evbit[0] = BIT_MASK(EV_KEY);
set_bit(KEY_SLEEP, input->keybit);
break;
case ACPI_BUTTON_TYPE_LID:
input->evbit[0] = BIT_MASK(EV_SW);
set_bit(SW_LID, input->swbit);
break;
}
error = input_register_device(input);
if (error)
goto err_remove_handlers;
if (button->type == ACPI_BUTTON_TYPE_LID)
acpi_lid_send_state(button);
if (device->wakeup.flags.valid) {
/* Button's GPE is run-wake GPE */
acpi_set_gpe_type(device->wakeup.gpe_device,
device->wakeup.gpe_number,
ACPI_GPE_TYPE_WAKE_RUN);
acpi_enable_gpe(device->wakeup.gpe_device,
device->wakeup.gpe_number);
device->wakeup.state.enabled = 1;
}
printk(KERN_INFO PREFIX "%s [%s]\n",
acpi_device_name(device), acpi_device_bid(device));
return 0;
err_remove_handlers:
acpi_button_remove_notify_handlers(button);
err_remove_fs:
acpi_button_remove_fs(device);
err_free_input:
input_free_device(input);
err_free_button:
kfree(button);
return error;
}
static int acpi_button_remove(struct acpi_device *device, int type)
{
struct acpi_button *button;
if (!device || !acpi_driver_data(device))
return -EINVAL;
button = acpi_driver_data(device);
acpi_button_remove_notify_handlers(button);
acpi_button_remove_fs(device);
input_unregister_device(button->input);
kfree(button);
return 0;
}
static int __init acpi_button_init(void)
{
int result;
acpi_button_dir = proc_mkdir(ACPI_BUTTON_CLASS, acpi_root_dir);
if (!acpi_button_dir)
return -ENODEV;
result = acpi_bus_register_driver(&acpi_button_driver);
if (result < 0) {
remove_proc_entry(ACPI_BUTTON_CLASS, acpi_root_dir);
return -ENODEV;
}
return 0;
}
static void __exit acpi_button_exit(void)
{
acpi_bus_unregister_driver(&acpi_button_driver);
if (acpi_power_dir)
remove_proc_entry(ACPI_BUTTON_SUBCLASS_POWER, acpi_button_dir);
if (acpi_sleep_dir)
remove_proc_entry(ACPI_BUTTON_SUBCLASS_SLEEP, acpi_button_dir);
if (acpi_lid_dir)
remove_proc_entry(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);
remove_proc_entry(ACPI_BUTTON_CLASS, acpi_root_dir);
}
module_init(acpi_button_init);
module_exit(acpi_button_exit);