linux/drivers/platform/x86/dell-rbtn.c
Pali Rohár 149ed3d404 change email address for Pali Rohár
For security reasons I stopped using gmail account and kernel address is
now up-to-date alias to my personal address.

People periodically send me emails to address which they found in source
code of drivers, so this change reflects state where people can contact
me.

[ Added .mailmap entry as per Joe Perches  - Linus ]
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Joe Perches <joe@perches.com>
Link: http://lkml.kernel.org/r/20200307104237.8199-1-pali@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-10 15:36:22 -07:00

500 lines
10 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
Dell Airplane Mode Switch driver
Copyright (C) 2014-2015 Pali Rohár <pali@kernel.org>
*/
#include <linux/module.h>
#include <linux/acpi.h>
#include <linux/rfkill.h>
#include <linux/input.h>
#include "dell-rbtn.h"
enum rbtn_type {
RBTN_UNKNOWN,
RBTN_TOGGLE,
RBTN_SLIDER,
};
struct rbtn_data {
enum rbtn_type type;
struct rfkill *rfkill;
struct input_dev *input_dev;
bool suspended;
};
/*
* acpi functions
*/
static enum rbtn_type rbtn_check(struct acpi_device *device)
{
unsigned long long output;
acpi_status status;
status = acpi_evaluate_integer(device->handle, "CRBT", NULL, &output);
if (ACPI_FAILURE(status))
return RBTN_UNKNOWN;
switch (output) {
case 0:
case 1:
return RBTN_TOGGLE;
case 2:
case 3:
return RBTN_SLIDER;
default:
return RBTN_UNKNOWN;
}
}
static int rbtn_get(struct acpi_device *device)
{
unsigned long long output;
acpi_status status;
status = acpi_evaluate_integer(device->handle, "GRBT", NULL, &output);
if (ACPI_FAILURE(status))
return -EINVAL;
return !output;
}
static int rbtn_acquire(struct acpi_device *device, bool enable)
{
struct acpi_object_list input;
union acpi_object param;
acpi_status status;
param.type = ACPI_TYPE_INTEGER;
param.integer.value = enable;
input.count = 1;
input.pointer = &param;
status = acpi_evaluate_object(device->handle, "ARBT", &input, NULL);
if (ACPI_FAILURE(status))
return -EINVAL;
return 0;
}
/*
* rfkill device
*/
static void rbtn_rfkill_query(struct rfkill *rfkill, void *data)
{
struct acpi_device *device = data;
int state;
state = rbtn_get(device);
if (state < 0)
return;
rfkill_set_states(rfkill, state, state);
}
static int rbtn_rfkill_set_block(void *data, bool blocked)
{
/* NOTE: setting soft rfkill state is not supported */
return -EINVAL;
}
static const struct rfkill_ops rbtn_ops = {
.query = rbtn_rfkill_query,
.set_block = rbtn_rfkill_set_block,
};
static int rbtn_rfkill_init(struct acpi_device *device)
{
struct rbtn_data *rbtn_data = device->driver_data;
int ret;
if (rbtn_data->rfkill)
return 0;
/*
* NOTE: rbtn controls all radio devices, not only WLAN
* but rfkill interface does not support "ANY" type
* so "WLAN" type is used
*/
rbtn_data->rfkill = rfkill_alloc("dell-rbtn", &device->dev,
RFKILL_TYPE_WLAN, &rbtn_ops, device);
if (!rbtn_data->rfkill)
return -ENOMEM;
ret = rfkill_register(rbtn_data->rfkill);
if (ret) {
rfkill_destroy(rbtn_data->rfkill);
rbtn_data->rfkill = NULL;
return ret;
}
return 0;
}
static void rbtn_rfkill_exit(struct acpi_device *device)
{
struct rbtn_data *rbtn_data = device->driver_data;
if (!rbtn_data->rfkill)
return;
rfkill_unregister(rbtn_data->rfkill);
rfkill_destroy(rbtn_data->rfkill);
rbtn_data->rfkill = NULL;
}
static void rbtn_rfkill_event(struct acpi_device *device)
{
struct rbtn_data *rbtn_data = device->driver_data;
if (rbtn_data->rfkill)
rbtn_rfkill_query(rbtn_data->rfkill, device);
}
/*
* input device
*/
static int rbtn_input_init(struct rbtn_data *rbtn_data)
{
int ret;
rbtn_data->input_dev = input_allocate_device();
if (!rbtn_data->input_dev)
return -ENOMEM;
rbtn_data->input_dev->name = "DELL Wireless hotkeys";
rbtn_data->input_dev->phys = "dellabce/input0";
rbtn_data->input_dev->id.bustype = BUS_HOST;
rbtn_data->input_dev->evbit[0] = BIT(EV_KEY);
set_bit(KEY_RFKILL, rbtn_data->input_dev->keybit);
ret = input_register_device(rbtn_data->input_dev);
if (ret) {
input_free_device(rbtn_data->input_dev);
rbtn_data->input_dev = NULL;
return ret;
}
return 0;
}
static void rbtn_input_exit(struct rbtn_data *rbtn_data)
{
input_unregister_device(rbtn_data->input_dev);
rbtn_data->input_dev = NULL;
}
static void rbtn_input_event(struct rbtn_data *rbtn_data)
{
input_report_key(rbtn_data->input_dev, KEY_RFKILL, 1);
input_sync(rbtn_data->input_dev);
input_report_key(rbtn_data->input_dev, KEY_RFKILL, 0);
input_sync(rbtn_data->input_dev);
}
/*
* acpi driver
*/
static int rbtn_add(struct acpi_device *device);
static int rbtn_remove(struct acpi_device *device);
static void rbtn_notify(struct acpi_device *device, u32 event);
static const struct acpi_device_id rbtn_ids[] = {
{ "DELRBTN", 0 },
{ "DELLABCE", 0 },
/*
* This driver can also handle the "DELLABC6" device that
* appears on the XPS 13 9350, but that device is disabled by
* the DSDT unless booted with acpi_osi="!Windows 2012"
* acpi_osi="!Windows 2013".
*
* According to Mario at Dell:
*
* DELLABC6 is a custom interface that was created solely to
* have airplane mode support for Windows 7. For Windows 10
* the proper interface is to use that which is handled by
* intel-hid. A OEM airplane mode driver is not used.
*
* Since the kernel doesn't identify as Windows 7 it would be
* incorrect to do attempt to use that interface.
*
* Even if we override _OSI and bind to DELLABC6, we end up with
* inconsistent behavior in which userspace can get out of sync
* with the rfkill state as it conflicts with events from
* intel-hid.
*
* The upshot is that it is better to just ignore DELLABC6
* devices.
*/
{ "", 0 },
};
#ifdef CONFIG_PM_SLEEP
static void ACPI_SYSTEM_XFACE rbtn_clear_suspended_flag(void *context)
{
struct rbtn_data *rbtn_data = context;
rbtn_data->suspended = false;
}
static int rbtn_suspend(struct device *dev)
{
struct acpi_device *device = to_acpi_device(dev);
struct rbtn_data *rbtn_data = acpi_driver_data(device);
rbtn_data->suspended = true;
return 0;
}
static int rbtn_resume(struct device *dev)
{
struct acpi_device *device = to_acpi_device(dev);
struct rbtn_data *rbtn_data = acpi_driver_data(device);
acpi_status status;
/*
* Upon resume, some BIOSes send an ACPI notification thet triggers
* an unwanted input event. In order to ignore it, we use a flag
* that we set at suspend and clear once we have received the extra
* ACPI notification. Since ACPI notifications are delivered
* asynchronously to drivers, we clear the flag from the workqueue
* used to deliver the notifications. This should be enough
* to have the flag cleared only after we received the extra
* notification, if any.
*/
status = acpi_os_execute(OSL_NOTIFY_HANDLER,
rbtn_clear_suspended_flag, rbtn_data);
if (ACPI_FAILURE(status))
rbtn_clear_suspended_flag(rbtn_data);
return 0;
}
#endif
static SIMPLE_DEV_PM_OPS(rbtn_pm_ops, rbtn_suspend, rbtn_resume);
static struct acpi_driver rbtn_driver = {
.name = "dell-rbtn",
.ids = rbtn_ids,
.drv.pm = &rbtn_pm_ops,
.ops = {
.add = rbtn_add,
.remove = rbtn_remove,
.notify = rbtn_notify,
},
.owner = THIS_MODULE,
};
/*
* notifier export functions
*/
static bool auto_remove_rfkill = true;
static ATOMIC_NOTIFIER_HEAD(rbtn_chain_head);
static int rbtn_inc_count(struct device *dev, void *data)
{
struct acpi_device *device = to_acpi_device(dev);
struct rbtn_data *rbtn_data = device->driver_data;
int *count = data;
if (rbtn_data->type == RBTN_SLIDER)
(*count)++;
return 0;
}
static int rbtn_switch_dev(struct device *dev, void *data)
{
struct acpi_device *device = to_acpi_device(dev);
struct rbtn_data *rbtn_data = device->driver_data;
bool enable = data;
if (rbtn_data->type != RBTN_SLIDER)
return 0;
if (enable)
rbtn_rfkill_init(device);
else
rbtn_rfkill_exit(device);
return 0;
}
int dell_rbtn_notifier_register(struct notifier_block *nb)
{
bool first;
int count;
int ret;
count = 0;
ret = driver_for_each_device(&rbtn_driver.drv, NULL, &count,
rbtn_inc_count);
if (ret || count == 0)
return -ENODEV;
first = !rbtn_chain_head.head;
ret = atomic_notifier_chain_register(&rbtn_chain_head, nb);
if (ret != 0)
return ret;
if (auto_remove_rfkill && first)
ret = driver_for_each_device(&rbtn_driver.drv, NULL,
(void *)false, rbtn_switch_dev);
return ret;
}
EXPORT_SYMBOL_GPL(dell_rbtn_notifier_register);
int dell_rbtn_notifier_unregister(struct notifier_block *nb)
{
int ret;
ret = atomic_notifier_chain_unregister(&rbtn_chain_head, nb);
if (ret != 0)
return ret;
if (auto_remove_rfkill && !rbtn_chain_head.head)
ret = driver_for_each_device(&rbtn_driver.drv, NULL,
(void *)true, rbtn_switch_dev);
return ret;
}
EXPORT_SYMBOL_GPL(dell_rbtn_notifier_unregister);
/*
* acpi driver functions
*/
static int rbtn_add(struct acpi_device *device)
{
struct rbtn_data *rbtn_data;
enum rbtn_type type;
int ret = 0;
type = rbtn_check(device);
if (type == RBTN_UNKNOWN) {
dev_info(&device->dev, "Unknown device type\n");
return -EINVAL;
}
ret = rbtn_acquire(device, true);
if (ret < 0) {
dev_err(&device->dev, "Cannot enable device\n");
return ret;
}
rbtn_data = devm_kzalloc(&device->dev, sizeof(*rbtn_data), GFP_KERNEL);
if (!rbtn_data)
return -ENOMEM;
rbtn_data->type = type;
device->driver_data = rbtn_data;
switch (rbtn_data->type) {
case RBTN_TOGGLE:
ret = rbtn_input_init(rbtn_data);
break;
case RBTN_SLIDER:
if (auto_remove_rfkill && rbtn_chain_head.head)
ret = 0;
else
ret = rbtn_rfkill_init(device);
break;
default:
ret = -EINVAL;
}
return ret;
}
static int rbtn_remove(struct acpi_device *device)
{
struct rbtn_data *rbtn_data = device->driver_data;
switch (rbtn_data->type) {
case RBTN_TOGGLE:
rbtn_input_exit(rbtn_data);
break;
case RBTN_SLIDER:
rbtn_rfkill_exit(device);
break;
default:
break;
}
rbtn_acquire(device, false);
device->driver_data = NULL;
return 0;
}
static void rbtn_notify(struct acpi_device *device, u32 event)
{
struct rbtn_data *rbtn_data = device->driver_data;
/*
* Some BIOSes send a notification at resume.
* Ignore it to prevent unwanted input events.
*/
if (rbtn_data->suspended) {
dev_dbg(&device->dev, "ACPI notification ignored\n");
return;
}
if (event != 0x80) {
dev_info(&device->dev, "Received unknown event (0x%x)\n",
event);
return;
}
switch (rbtn_data->type) {
case RBTN_TOGGLE:
rbtn_input_event(rbtn_data);
break;
case RBTN_SLIDER:
rbtn_rfkill_event(device);
atomic_notifier_call_chain(&rbtn_chain_head, event, device);
break;
default:
break;
}
}
/*
* module functions
*/
module_acpi_driver(rbtn_driver);
module_param(auto_remove_rfkill, bool, 0444);
MODULE_PARM_DESC(auto_remove_rfkill, "Automatically remove rfkill devices when "
"other modules start receiving events "
"from this module and re-add them when "
"the last module stops receiving events "
"(default true)");
MODULE_DEVICE_TABLE(acpi, rbtn_ids);
MODULE_DESCRIPTION("Dell Airplane Mode Switch driver");
MODULE_AUTHOR("Pali Rohár <pali@kernel.org>");
MODULE_LICENSE("GPL");