[mirror_ubuntu-artful-kernel.git] / drivers / platform / x86 / dell-rbtn.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;
	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 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".  Even if we boot that and bind
	 * the driver, we seem to have inconsistent behavior in
	 * which NetworkManager can get out of sync with the rfkill
	 * state.
	 *
	 * On the XPS 13 9350 and similar laptops, we're not supposed to
	 * use DELLABC6 at all.  Instead, we handle the rfkill button
	 * via the intel-hid driver.
	 */

	{ "", 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.rohar@gmail.com>");
MODULE_LICENSE("GPL");
Commit	Line	Data
817a5cdb PR	1	/*
	2	Dell Airplane Mode Switch driver
	3	Copyright (C) 2014-2015 Pali Rohár <pali.rohar@gmail.com>
	4
	5	This program is free software; you can redistribute it and/or modify
	6	it under the terms of the GNU General Public License as published by
	7	the Free Software Foundation; either version 2 of the License, or
	8	(at your option) any later version.
	9
	10	This program is distributed in the hope that it will be useful,
	11	but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	13	GNU General Public License for more details.
	14	*/
	15
	16	#include <linux/module.h>
	17	#include <linux/acpi.h>
	18	#include <linux/rfkill.h>
	19	#include <linux/input.h>
	20
	21	enum rbtn_type {
	22	RBTN_UNKNOWN,
	23	RBTN_TOGGLE,
	24	RBTN_SLIDER,
	25	};
	26
	27	struct rbtn_data {
	28	enum rbtn_type type;
	29	struct rfkill *rfkill;
	30	struct input_dev *input_dev;
ff865123	31	bool suspended;
817a5cdb PR	32	};
	33
	34
	35	/*
	36	* acpi functions
	37	*/
	38
	39	static enum rbtn_type rbtn_check(struct acpi_device *device)
	40	{
	41	unsigned long long output;
	42	acpi_status status;
	43
	44	status = acpi_evaluate_integer(device->handle, "CRBT", NULL, &output);
	45	if (ACPI_FAILURE(status))
	46	return RBTN_UNKNOWN;
	47
	48	switch (output) {
	49	case 0:
	50	case 1:
	51	return RBTN_TOGGLE;
	52	case 2:
	53	case 3:
	54	return RBTN_SLIDER;
	55	default:
	56	return RBTN_UNKNOWN;
	57	}
	58	}
	59
	60	static int rbtn_get(struct acpi_device *device)
	61	{
	62	unsigned long long output;
	63	acpi_status status;
	64
	65	status = acpi_evaluate_integer(device->handle, "GRBT", NULL, &output);
	66	if (ACPI_FAILURE(status))
	67	return -EINVAL;
	68
	69	return !output;
	70	}
	71
	72	static int rbtn_acquire(struct acpi_device *device, bool enable)
	73	{
	74	struct acpi_object_list input;
	75	union acpi_object param;
	76	acpi_status status;
	77
	78	param.type = ACPI_TYPE_INTEGER;
	79	param.integer.value = enable;
	80	input.count = 1;
	81	input.pointer = &param;
	82
	83	status = acpi_evaluate_object(device->handle, "ARBT", &input, NULL);
	84	if (ACPI_FAILURE(status))
	85	return -EINVAL;
	86
	87	return 0;
	88	}
	89
	90
	91	/*
	92	* rfkill device
	93	*/
	94
	95	static void rbtn_rfkill_query(struct rfkill rfkill, void data)
96	{
97	struct acpi_device *device = data;
98	int state;
99
100	state = rbtn_get(device);
101	if (state < 0)
102	return;
103
104	rfkill_set_states(rfkill, state, state);
105	}
106
107	static int rbtn_rfkill_set_block(void *data, bool blocked)
108	{
109	/* NOTE: setting soft rfkill state is not supported */
110	return -EINVAL;
111	}
112
113	static struct rfkill_ops rbtn_ops = {
114	.query = rbtn_rfkill_query,
115	.set_block = rbtn_rfkill_set_block,
116	};
117
118	static int rbtn_rfkill_init(struct acpi_device *device)
119	{
120	struct rbtn_data *rbtn_data = device->driver_data;
121	int ret;
122
123	if (rbtn_data->rfkill)
124	return 0;
125
126	/*
127	* NOTE: rbtn controls all radio devices, not only WLAN
128	* but rfkill interface does not support "ANY" type
129	* so "WLAN" type is used
130	*/
131	rbtn_data->rfkill = rfkill_alloc("dell-rbtn", &device->dev,
132	RFKILL_TYPE_WLAN, &rbtn_ops, device);
133	if (!rbtn_data->rfkill)
134	return -ENOMEM;
135
136	ret = rfkill_register(rbtn_data->rfkill);
137	if (ret) {
138	rfkill_destroy(rbtn_data->rfkill);
139	rbtn_data->rfkill = NULL;
140	return ret;
141	}
142
143	return 0;
144	}
145
146	static void rbtn_rfkill_exit(struct acpi_device *device)
147	{
148	struct rbtn_data *rbtn_data = device->driver_data;
149
150	if (!rbtn_data->rfkill)
151	return;
152
153	rfkill_unregister(rbtn_data->rfkill);
154	rfkill_destroy(rbtn_data->rfkill);
155	rbtn_data->rfkill = NULL;
156	}
157
158	static void rbtn_rfkill_event(struct acpi_device *device)
159	{
160	struct rbtn_data *rbtn_data = device->driver_data;
161
162	if (rbtn_data->rfkill)
163	rbtn_rfkill_query(rbtn_data->rfkill, device);
164	}
165
166
167	/*
168	* input device
169	*/
170
171	static int rbtn_input_init(struct rbtn_data *rbtn_data)
172	{
173	int ret;
174
175	rbtn_data->input_dev = input_allocate_device();
176	if (!rbtn_data->input_dev)
177	return -ENOMEM;
178
179	rbtn_data->input_dev->name = "DELL Wireless hotkeys";
180	rbtn_data->input_dev->phys = "dellabce/input0";
181	rbtn_data->input_dev->id.bustype = BUS_HOST;
182	rbtn_data->input_dev->evbit[0] = BIT(EV_KEY);
183	set_bit(KEY_RFKILL, rbtn_data->input_dev->keybit);
184
185	ret = input_register_device(rbtn_data->input_dev);
186	if (ret) {
187	input_free_device(rbtn_data->input_dev);
188	rbtn_data->input_dev = NULL;
189	return ret;
190	}
191
192	return 0;
193	}
194
195	static void rbtn_input_exit(struct rbtn_data *rbtn_data)
196	{
197	input_unregister_device(rbtn_data->input_dev);
198	rbtn_data->input_dev = NULL;
199	}
200
201	static void rbtn_input_event(struct rbtn_data *rbtn_data)
202	{
203	input_report_key(rbtn_data->input_dev, KEY_RFKILL, 1);
204	input_sync(rbtn_data->input_dev);
205	input_report_key(rbtn_data->input_dev, KEY_RFKILL, 0);
206	input_sync(rbtn_data->input_dev);
207	}
208
209
210	/*
211	* acpi driver
212	*/
213
214	static int rbtn_add(struct acpi_device *device);
215	static int rbtn_remove(struct acpi_device *device);
216	static void rbtn_notify(struct acpi_device *device, u32 event);
217
218	static const struct acpi_device_id rbtn_ids[] = {
219	{ "DELRBTN", 0 },
220	{ "DELLABCE", 0 },
4d340c6b AL	221
	222	/*
	223	* This driver can also handle the "DELLABC6" device that
	224	* appears on the XPS 13 9350, but that device is disabled
	225	* by the DSDT unless booted with acpi_osi="!Windows 2012"
	226	* acpi_osi="!Windows 2013". Even if we boot that and bind
	227	* the driver, we seem to have inconsistent behavior in
	228	* which NetworkManager can get out of sync with the rfkill
	229	* state.
	230	*
	231	* On the XPS 13 9350 and similar laptops, we're not supposed to
	232	* use DELLABC6 at all. Instead, we handle the rfkill button
	233	* via the intel-hid driver.
	234	*/
	235
817a5cdb PR	236	{ "", 0 },
	237	};
	238
ff865123 GM	239	#ifdef CONFIG_PM_SLEEP
	240	static void ACPI_SYSTEM_XFACE rbtn_clear_suspended_flag(void *context)
	241	{
	242	struct rbtn_data *rbtn_data = context;
	243
	244	rbtn_data->suspended = false;
	245	}
	246
	247	static int rbtn_suspend(struct device *dev)
	248	{
	249	struct acpi_device *device = to_acpi_device(dev);
	250	struct rbtn_data *rbtn_data = acpi_driver_data(device);
	251
	252	rbtn_data->suspended = true;
	253
	254	return 0;
	255	}
	256
	257	static int rbtn_resume(struct device *dev)
	258	{
	259	struct acpi_device *device = to_acpi_device(dev);
	260	struct rbtn_data *rbtn_data = acpi_driver_data(device);
	261	acpi_status status;
	262
	263	/*
	264	* Upon resume, some BIOSes send an ACPI notification thet triggers
	265	* an unwanted input event. In order to ignore it, we use a flag
	266	* that we set at suspend and clear once we have received the extra
	267	* ACPI notification. Since ACPI notifications are delivered
	268	* asynchronously to drivers, we clear the flag from the workqueue
	269	* used to deliver the notifications. This should be enough
	270	* to have the flag cleared only after we received the extra
	271	* notification, if any.
	272	*/
	273	status = acpi_os_execute(OSL_NOTIFY_HANDLER,
	274	rbtn_clear_suspended_flag, rbtn_data);
	275	if (ACPI_FAILURE(status))
	276	rbtn_clear_suspended_flag(rbtn_data);
	277
	278	return 0;
	279	}
	280	#endif
	281
	282	static SIMPLE_DEV_PM_OPS(rbtn_pm_ops, rbtn_suspend, rbtn_resume);
	283
817a5cdb PR	284	static struct acpi_driver rbtn_driver = {
	285	.name = "dell-rbtn",
	286	.ids = rbtn_ids,
ff865123	287	.drv.pm = &rbtn_pm_ops,
817a5cdb PR	288	.ops = {
	289	.add = rbtn_add,
	290	.remove = rbtn_remove,
	291	.notify = rbtn_notify,
	292	},
	293	.owner = THIS_MODULE,
	294	};
	295
	296
b05ffc95 PR	297	/*
	298	* notifier export functions
	299	*/
	300
	301	static bool auto_remove_rfkill = true;
	302
	303	static ATOMIC_NOTIFIER_HEAD(rbtn_chain_head);
	304
	305	static int rbtn_inc_count(struct device dev, void data)
	306	{
	307	struct acpi_device *device = to_acpi_device(dev);
	308	struct rbtn_data *rbtn_data = device->driver_data;
	309	int *count = data;
	310
	311	if (rbtn_data->type == RBTN_SLIDER)
	312	(*count)++;
	313
	314	return 0;
	315	}
	316
	317	static int rbtn_switch_dev(struct device dev, void data)
	318	{
	319	struct acpi_device *device = to_acpi_device(dev);
	320	struct rbtn_data *rbtn_data = device->driver_data;
	321	bool enable = data;
	322
	323	if (rbtn_data->type != RBTN_SLIDER)
	324	return 0;
	325
	326	if (enable)
	327	rbtn_rfkill_init(device);
	328	else
	329	rbtn_rfkill_exit(device);
	330
	331	return 0;
	332	}
	333
	334	int dell_rbtn_notifier_register(struct notifier_block *nb)
	335	{
	336	bool first;
	337	int count;
	338	int ret;
	339
	340	count = 0;
	341	ret = driver_for_each_device(&rbtn_driver.drv, NULL, &count,
	342	rbtn_inc_count);
	343	if (ret \|\| count == 0)
	344	return -ENODEV;
	345
	346	first = !rbtn_chain_head.head;
	347
	348	ret = atomic_notifier_chain_register(&rbtn_chain_head, nb);
	349	if (ret != 0)
	350	return ret;
	351
	352	if (auto_remove_rfkill && first)
	353	ret = driver_for_each_device(&rbtn_driver.drv, NULL,
	354	(void *)false, rbtn_switch_dev);
	355
	356	return ret;
	357	}
	358	EXPORT_SYMBOL_GPL(dell_rbtn_notifier_register);
	359
	360	int dell_rbtn_notifier_unregister(struct notifier_block *nb)
361	{
362	int ret;
363
364	ret = atomic_notifier_chain_unregister(&rbtn_chain_head, nb);
365	if (ret != 0)
366	return ret;
367
368	if (auto_remove_rfkill && !rbtn_chain_head.head)
369	ret = driver_for_each_device(&rbtn_driver.drv, NULL,
370	(void *)true, rbtn_switch_dev);
371
372	return ret;
373	}
374	EXPORT_SYMBOL_GPL(dell_rbtn_notifier_unregister);
375
376
817a5cdb PR	377	/*
	378	* acpi driver functions
	379	*/
	380
	381	static int rbtn_add(struct acpi_device *device)
	382	{
	383	struct rbtn_data *rbtn_data;
	384	enum rbtn_type type;
	385	int ret = 0;
	386
	387	type = rbtn_check(device);
	388	if (type == RBTN_UNKNOWN) {
	389	dev_info(&device->dev, "Unknown device type\n");
	390	return -EINVAL;
	391	}
	392
	393	ret = rbtn_acquire(device, true);
	394	if (ret < 0) {
	395	dev_err(&device->dev, "Cannot enable device\n");
	396	return ret;
	397	}
	398
	399	rbtn_data = devm_kzalloc(&device->dev, sizeof(*rbtn_data), GFP_KERNEL);
	400	if (!rbtn_data)
	401	return -ENOMEM;
	402
	403	rbtn_data->type = type;
	404	device->driver_data = rbtn_data;
	405
	406	switch (rbtn_data->type) {
	407	case RBTN_TOGGLE:
	408	ret = rbtn_input_init(rbtn_data);
	409	break;
	410	case RBTN_SLIDER:
b05ffc95 PR	411	if (auto_remove_rfkill && rbtn_chain_head.head)
	412	ret = 0;
	413	else
	414	ret = rbtn_rfkill_init(device);
817a5cdb PR	415	break;
	416	default:
	417	ret = -EINVAL;
	418	}
	419
	420	return ret;
	421
	422	}
	423
	424	static int rbtn_remove(struct acpi_device *device)
	425	{
	426	struct rbtn_data *rbtn_data = device->driver_data;
	427
	428	switch (rbtn_data->type) {
	429	case RBTN_TOGGLE:
	430	rbtn_input_exit(rbtn_data);
	431	break;
	432	case RBTN_SLIDER:
	433	rbtn_rfkill_exit(device);
	434	break;
	435	default:
	436	break;
	437	}
	438
	439	rbtn_acquire(device, false);
	440	device->driver_data = NULL;
	441
	442	return 0;
	443	}
	444
	445	static void rbtn_notify(struct acpi_device *device, u32 event)
	446	{
	447	struct rbtn_data *rbtn_data = device->driver_data;
	448
ff865123 GM	449	/*
	450	* Some BIOSes send a notification at resume.
	451	* Ignore it to prevent unwanted input events.
	452	*/
	453	if (rbtn_data->suspended) {
	454	dev_dbg(&device->dev, "ACPI notification ignored\n");
	455	return;
	456	}
	457
817a5cdb PR	458	if (event != 0x80) {
	459	dev_info(&device->dev, "Received unknown event (0x%x)\n",
	460	event);
	461	return;
	462	}
	463
	464	switch (rbtn_data->type) {
	465	case RBTN_TOGGLE:
	466	rbtn_input_event(rbtn_data);
	467	break;
	468	case RBTN_SLIDER:
	469	rbtn_rfkill_event(device);
b05ffc95	470	atomic_notifier_call_chain(&rbtn_chain_head, event, device);
817a5cdb PR	471	break;
	472	default:
	473	break;
	474	}
	475	}
	476
	477
	478	/*
	479	* module functions
	480	*/
	481
	482	module_acpi_driver(rbtn_driver);
	483
b05ffc95 PR	484	module_param(auto_remove_rfkill, bool, 0444);
	485
	486	MODULE_PARM_DESC(auto_remove_rfkill, "Automatically remove rfkill devices when "
	487	"other modules start receiving events "
	488	"from this module and re-add them when "
	489	"the last module stops receiving events "
	490	"(default true)");
817a5cdb PR	491	MODULE_DEVICE_TABLE(acpi, rbtn_ids);
	492	MODULE_DESCRIPTION("Dell Airplane Mode Switch driver");
	493	MODULE_AUTHOR("Pali Rohár <pali.rohar@gmail.com>");
	494	MODULE_LICENSE("GPL");