[mirror_ubuntu-jammy-kernel.git] / drivers / platform / x86 / surface3_button.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Supports for the button array on the Surface tablets.
 *
 * (C) Copyright 2016 Red Hat, Inc
 *
 * Based on soc_button_array.c:
 *
 * {C} Copyright 2014 Intel Corporation
 */

#include <linux/module.h>
#include <linux/input.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/acpi.h>
#include <linux/gpio/consumer.h>
#include <linux/gpio_keys.h>
#include <linux/gpio.h>
#include <linux/platform_device.h>


#define SURFACE_BUTTON_OBJ_NAME		"TEV2"
#define MAX_NBUTTONS			4

/*
 * Some of the buttons like volume up/down are auto repeat, while others
 * are not. To support both, we register two platform devices, and put
 * buttons into them based on whether the key should be auto repeat.
 */
#define BUTTON_TYPES			2

/*
 * Power button, Home button, Volume buttons support is supposed to
 * be covered by drivers/input/misc/soc_button_array.c, which is implemented
 * according to "Windows ACPI Design Guide for SoC Platforms".
 * However surface 3 seems not to obey the specs, instead it uses
 * device TEV2(MSHW0028) for declaring the GPIOs. The gpios are also slightly
 * different in which the Home button is active high.
 * Compared to surfacepro3_button.c which also handles MSHW0028, the Surface 3
 * is a reduce platform and thus uses GPIOs, not ACPI events.
 * We choose an I2C driver here because we need to access the resources
 * declared under the device node, while surfacepro3_button.c only needs
 * the ACPI companion node.
 */
static const struct acpi_device_id surface3_acpi_match[] = {
	{ "MSHW0028", 0 },
	{ }
};
MODULE_DEVICE_TABLE(acpi, surface3_acpi_match);

struct surface3_button_info {
	const char *name;
	int acpi_index;
	unsigned int event_type;
	unsigned int event_code;
	bool autorepeat;
	bool wakeup;
	bool active_low;
};

struct surface3_button_data {
	struct platform_device *children[BUTTON_TYPES];
};

/*
 * Get the Nth GPIO number from the ACPI object.
 */
static int surface3_button_lookup_gpio(struct device *dev, int acpi_index)
{
	struct gpio_desc *desc;
	int gpio;

	desc = gpiod_get_index(dev, NULL, acpi_index, GPIOD_ASIS);
	if (IS_ERR(desc))
		return PTR_ERR(desc);

	gpio = desc_to_gpio(desc);

	gpiod_put(desc);

	return gpio;
}

static struct platform_device *
surface3_button_device_create(struct i2c_client *client,
			      const struct surface3_button_info *button_info,
			      bool autorepeat)
{
	const struct surface3_button_info *info;
	struct platform_device *pd;
	struct gpio_keys_button *gpio_keys;
	struct gpio_keys_platform_data *gpio_keys_pdata;
	int n_buttons = 0;
	int gpio;
	int error;

	gpio_keys_pdata = devm_kzalloc(&client->dev,
				       sizeof(*gpio_keys_pdata) +
				       sizeof(*gpio_keys) * MAX_NBUTTONS,
				       GFP_KERNEL);
	if (!gpio_keys_pdata)
		return ERR_PTR(-ENOMEM);

	gpio_keys = (void *)(gpio_keys_pdata + 1);

	for (info = button_info; info->name; info++) {
		if (info->autorepeat != autorepeat)
			continue;

		gpio = surface3_button_lookup_gpio(&client->dev,
						   info->acpi_index);
		if (!gpio_is_valid(gpio))
			continue;

		gpio_keys[n_buttons].type = info->event_type;
		gpio_keys[n_buttons].code = info->event_code;
		gpio_keys[n_buttons].gpio = gpio;
		gpio_keys[n_buttons].active_low = info->active_low;
		gpio_keys[n_buttons].desc = info->name;
		gpio_keys[n_buttons].wakeup = info->wakeup;
		n_buttons++;
	}

	if (n_buttons == 0) {
		error = -ENODEV;
		goto err_free_mem;
	}

	gpio_keys_pdata->buttons = gpio_keys;
	gpio_keys_pdata->nbuttons = n_buttons;
	gpio_keys_pdata->rep = autorepeat;

	pd = platform_device_alloc("gpio-keys", PLATFORM_DEVID_AUTO);
	if (!pd) {
		error = -ENOMEM;
		goto err_free_mem;
	}

	error = platform_device_add_data(pd, gpio_keys_pdata,
					 sizeof(*gpio_keys_pdata));
	if (error)
		goto err_free_pdev;

	error = platform_device_add(pd);
	if (error)
		goto err_free_pdev;

	return pd;

err_free_pdev:
	platform_device_put(pd);
err_free_mem:
	devm_kfree(&client->dev, gpio_keys_pdata);
	return ERR_PTR(error);
}

static int surface3_button_remove(struct i2c_client *client)
{
	struct surface3_button_data *priv = i2c_get_clientdata(client);

	int i;

	for (i = 0; i < BUTTON_TYPES; i++)
		if (priv->children[i])
			platform_device_unregister(priv->children[i]);

	return 0;
}

static struct surface3_button_info surface3_button_surface3[] = {
	{ "power", 0, EV_KEY, KEY_POWER, false, true, true },
	{ "home", 1, EV_KEY, KEY_LEFTMETA, false, true, false },
	{ "volume_up", 2, EV_KEY, KEY_VOLUMEUP, true, false, true },
	{ "volume_down", 3, EV_KEY, KEY_VOLUMEDOWN, true, false, true },
	{ }
};

static int surface3_button_probe(struct i2c_client *client,
				 const struct i2c_device_id *id)
{
	struct device *dev = &client->dev;
	struct surface3_button_data *priv;
	struct platform_device *pd;
	int i;
	int error;

	if (strncmp(acpi_device_bid(ACPI_COMPANION(&client->dev)),
		    SURFACE_BUTTON_OBJ_NAME,
		    strlen(SURFACE_BUTTON_OBJ_NAME)))
		return -ENODEV;

	error = gpiod_count(dev, NULL);
	if (error < 0) {
		dev_dbg(dev, "no GPIO attached, ignoring...\n");
		return error;
	}

	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
	if (!priv)
		return -ENOMEM;

	i2c_set_clientdata(client, priv);

	for (i = 0; i < BUTTON_TYPES; i++) {
		pd = surface3_button_device_create(client,
						   surface3_button_surface3,
						   i == 0);
		if (IS_ERR(pd)) {
			error = PTR_ERR(pd);
			if (error != -ENODEV) {
				surface3_button_remove(client);
				return error;
			}
			continue;
		}

		priv->children[i] = pd;
	}

	if (!priv->children[0] && !priv->children[1])
		return -ENODEV;

	return 0;
}

static const struct i2c_device_id surface3_id[] = {
	{ }
};
MODULE_DEVICE_TABLE(i2c, surface3_id);

static struct i2c_driver surface3_driver = {
	.probe = surface3_button_probe,
	.remove = surface3_button_remove,
	.id_table = surface3_id,
	.driver = {
		.name = "surface3",
		.acpi_match_table = ACPI_PTR(surface3_acpi_match),
	},
};
module_i2c_driver(surface3_driver);

MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
MODULE_DESCRIPTION("surface3 button array driver");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
b886d83c	1	// SPDX-License-Identifier: GPL-2.0-only
1a64b719 BT	2	/*
	3	* Supports for the button array on the Surface tablets.
	4	*
	5	* (C) Copyright 2016 Red Hat, Inc
	6	*
	7	* Based on soc_button_array.c:
	8	*
	9	* {C} Copyright 2014 Intel Corporation
1a64b719 BT	10	*/
	11
	12	#include <linux/module.h>
	13	#include <linux/input.h>
	14	#include <linux/init.h>
	15	#include <linux/kernel.h>
	16	#include <linux/i2c.h>
	17	#include <linux/slab.h>
	18	#include <linux/acpi.h>
	19	#include <linux/gpio/consumer.h>
	20	#include <linux/gpio_keys.h>
	21	#include <linux/gpio.h>
	22	#include <linux/platform_device.h>
	23
	24
	25	#define SURFACE_BUTTON_OBJ_NAME "TEV2"
	26	#define MAX_NBUTTONS 4
	27
	28	/*
	29	* Some of the buttons like volume up/down are auto repeat, while others
	30	* are not. To support both, we register two platform devices, and put
	31	* buttons into them based on whether the key should be auto repeat.
	32	*/
	33	#define BUTTON_TYPES 2
	34
	35	/*
	36	* Power button, Home button, Volume buttons support is supposed to
	37	* be covered by drivers/input/misc/soc_button_array.c, which is implemented
	38	* according to "Windows ACPI Design Guide for SoC Platforms".
	39	* However surface 3 seems not to obey the specs, instead it uses
	40	* device TEV2(MSHW0028) for declaring the GPIOs. The gpios are also slightly
	41	* different in which the Home button is active high.
	42	* Compared to surfacepro3_button.c which also handles MSHW0028, the Surface 3
	43	* is a reduce platform and thus uses GPIOs, not ACPI events.
	44	* We choose an I2C driver here because we need to access the resources
	45	* declared under the device node, while surfacepro3_button.c only needs
	46	* the ACPI companion node.
	47	*/
	48	static const struct acpi_device_id surface3_acpi_match[] = {
	49	{ "MSHW0028", 0 },
	50	{ }
	51	};
	52	MODULE_DEVICE_TABLE(acpi, surface3_acpi_match);
	53
	54	struct surface3_button_info {
	55	const char *name;
	56	int acpi_index;
	57	unsigned int event_type;
	58	unsigned int event_code;
	59	bool autorepeat;
	60	bool wakeup;
	61	bool active_low;
	62	};
	63
	64	struct surface3_button_data {
	65	struct platform_device *children[BUTTON_TYPES];
	66	};
	67
	68	/*
	69	* Get the Nth GPIO number from the ACPI object.
	70	*/
	71	static int surface3_button_lookup_gpio(struct device *dev, int acpi_index)
	72	{
	73	struct gpio_desc *desc;
74	int gpio;
75
76	desc = gpiod_get_index(dev, NULL, acpi_index, GPIOD_ASIS);
77	if (IS_ERR(desc))
78	return PTR_ERR(desc);
79
80	gpio = desc_to_gpio(desc);
81
82	gpiod_put(desc);
83
84	return gpio;
85	}
86
87	static struct platform_device *
88	surface3_button_device_create(struct i2c_client *client,
89	const struct surface3_button_info *button_info,
90	bool autorepeat)
91	{
92	const struct surface3_button_info *info;
93	struct platform_device *pd;
94	struct gpio_keys_button *gpio_keys;
95	struct gpio_keys_platform_data *gpio_keys_pdata;
96	int n_buttons = 0;
97	int gpio;
98	int error;
99
100	gpio_keys_pdata = devm_kzalloc(&client->dev,
101	sizeof(*gpio_keys_pdata) +
102	sizeof(gpio_keys) MAX_NBUTTONS,
103	GFP_KERNEL);
104	if (!gpio_keys_pdata)
105	return ERR_PTR(-ENOMEM);
106
107	gpio_keys = (void *)(gpio_keys_pdata + 1);
108
109	for (info = button_info; info->name; info++) {
110	if (info->autorepeat != autorepeat)
111	continue;
112
113	gpio = surface3_button_lookup_gpio(&client->dev,
114	info->acpi_index);
115	if (!gpio_is_valid(gpio))
116	continue;
117
118	gpio_keys[n_buttons].type = info->event_type;
119	gpio_keys[n_buttons].code = info->event_code;
120	gpio_keys[n_buttons].gpio = gpio;
121	gpio_keys[n_buttons].active_low = info->active_low;
122	gpio_keys[n_buttons].desc = info->name;
123	gpio_keys[n_buttons].wakeup = info->wakeup;
124	n_buttons++;
125	}
126
127	if (n_buttons == 0) {
128	error = -ENODEV;
129	goto err_free_mem;
130	}
131
132	gpio_keys_pdata->buttons = gpio_keys;
133	gpio_keys_pdata->nbuttons = n_buttons;
134	gpio_keys_pdata->rep = autorepeat;
135
136	pd = platform_device_alloc("gpio-keys", PLATFORM_DEVID_AUTO);
137	if (!pd) {
138	error = -ENOMEM;
139	goto err_free_mem;
140	}
141
142	error = platform_device_add_data(pd, gpio_keys_pdata,
143	sizeof(*gpio_keys_pdata));
144	if (error)
145	goto err_free_pdev;
146
147	error = platform_device_add(pd);
148	if (error)
149	goto err_free_pdev;
150
151	return pd;
152
153	err_free_pdev:
154	platform_device_put(pd);
155	err_free_mem:
156	devm_kfree(&client->dev, gpio_keys_pdata);
157	return ERR_PTR(error);
158	}
159
160	static int surface3_button_remove(struct i2c_client *client)
161	{
162	struct surface3_button_data *priv = i2c_get_clientdata(client);
163
164	int i;
165
166	for (i = 0; i < BUTTON_TYPES; i++)
167	if (priv->children[i])
168	platform_device_unregister(priv->children[i]);
169
170	return 0;
171	}
172
173	static struct surface3_button_info surface3_button_surface3[] = {
174	{ "power", 0, EV_KEY, KEY_POWER, false, true, true },
175	{ "home", 1, EV_KEY, KEY_LEFTMETA, false, true, false },
176	{ "volume_up", 2, EV_KEY, KEY_VOLUMEUP, true, false, true },
177	{ "volume_down", 3, EV_KEY, KEY_VOLUMEDOWN, true, false, true },
178	{ }
179	};
180
181	static int surface3_button_probe(struct i2c_client *client,
182	const struct i2c_device_id *id)
183	{
184	struct device *dev = &client->dev;
185	struct surface3_button_data *priv;
186	struct platform_device *pd;
187	int i;
188	int error;
189
190	if (strncmp(acpi_device_bid(ACPI_COMPANION(&client->dev)),
191	SURFACE_BUTTON_OBJ_NAME,
192	strlen(SURFACE_BUTTON_OBJ_NAME)))
193	return -ENODEV;
194
562e7a40 AS	195	error = gpiod_count(dev, NULL);
562e7a40 AS	196	if (error < 0) {
1a64b719	197	dev_dbg(dev, "no GPIO attached, ignoring...\n");
562e7a40	198	return error;
1a64b719 BT	199	}
	200
	201	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
	202	if (!priv)
	203	return -ENOMEM;
	204
	205	i2c_set_clientdata(client, priv);
	206
	207	for (i = 0; i < BUTTON_TYPES; i++) {
	208	pd = surface3_button_device_create(client,
	209	surface3_button_surface3,
	210	i == 0);
	211	if (IS_ERR(pd)) {
	212	error = PTR_ERR(pd);
	213	if (error != -ENODEV) {
	214	surface3_button_remove(client);
	215	return error;
	216	}
	217	continue;
	218	}
	219
	220	priv->children[i] = pd;
	221	}
	222
	223	if (!priv->children[0] && !priv->children[1])
	224	return -ENODEV;
	225
	226	return 0;
	227	}
	228
	229	static const struct i2c_device_id surface3_id[] = {
	230	{ }
	231	};
	232	MODULE_DEVICE_TABLE(i2c, surface3_id);
	233
	234	static struct i2c_driver surface3_driver = {
	235	.probe = surface3_button_probe,
	236	.remove = surface3_button_remove,
	237	.id_table = surface3_id,
	238	.driver = {
	239	.name = "surface3",
	240	.acpi_match_table = ACPI_PTR(surface3_acpi_match),
	241	},
	242	};
	243	module_i2c_driver(surface3_driver);
	244
	245	MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
	246	MODULE_DESCRIPTION("surface3 button array driver");
	247	MODULE_LICENSE("GPL v2");