linux/drivers/platform/x86/dell-rbtn.c
Pali Rohár b05ffc95f9 dell-rbtn: Export notifier for other kernel modules
This patch exports notifier functions so other modules can receive HW
switch events. By default when some module register notifier, dell-rbtn
driver automatically remove rfkill interfaces from system (it is expected
that other module will use events for other rfkill interface). This
behaviour can be changed with new module parameter "auto_remove_rfkill".

This patch is designed for dell-laptop module for receiving those events.

Signed-off-by: Pali Rohár <pali.rohar@gmail.com>
Tested-by: Gabriele Mazzotta <gabriele.mzt@gmail.com>
[dvhart@linux.intel.com: Cleanup MODULE_PARM_DESC formatting and grammar]
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
2015-06-10 22:04:11 -07:00

424 lines
8.6 KiB
C

/*
Dell Airplane Mode Switch driver
Copyright (C) 2014-2015 Pali Rohár <pali.rohar@gmail.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.
*/
#include <linux/module.h>
#include <linux/acpi.h>
#include <linux/rfkill.h>
#include <linux/input.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;
};
/*
* 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 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 },
{ "", 0 },
};
static struct acpi_driver rbtn_driver = {
.name = "dell-rbtn",
.ids = rbtn_ids,
.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;
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.rohar@gmail.com>");
MODULE_LICENSE("GPL");