1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *  OLPC XO-1.5 ebook switch driver
4 *  (based on generic ACPI button driver)
5 *
6 *  Copyright (C) 2009 Paul Fox <pgf@laptop.org>
7 *  Copyright (C) 2010 One Laptop per Child
8 */
9
10#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11
12#include <linux/kernel.h>
13#include <linux/module.h>
14#include <linux/init.h>
15#include <linux/types.h>
16#include <linux/input.h>
17#include <linux/acpi.h>
18
19#define MODULE_NAME "xo15-ebook"
20
21#define XO15_EBOOK_CLASS		MODULE_NAME
22#define XO15_EBOOK_TYPE_UNKNOWN	0x00
23#define XO15_EBOOK_NOTIFY_STATUS	0x80
24
25#define XO15_EBOOK_SUBCLASS		"ebook"
26#define XO15_EBOOK_HID			"XO15EBK"
27#define XO15_EBOOK_DEVICE_NAME		"EBook Switch"
28
29ACPI_MODULE_NAME(MODULE_NAME);
30
31MODULE_DESCRIPTION("OLPC XO-1.5 ebook switch driver");
32MODULE_LICENSE("GPL");
33
34static const struct acpi_device_id ebook_device_ids[] = {
35	{ XO15_EBOOK_HID, 0 },
36	{ "", 0 },
37};
38MODULE_DEVICE_TABLE(acpi, ebook_device_ids);
39
40struct ebook_switch {
41	struct input_dev *input;
42	char phys[32];			/* for input device */
43};
44
45static int ebook_send_state(struct acpi_device *device)
46{
47	struct ebook_switch *button = acpi_driver_data(device);
48	unsigned long long state;
49	acpi_status status;
50
51	status = acpi_evaluate_integer(device->handle, "EBK", NULL, &state);
52	if (ACPI_FAILURE(status))
53		return -EIO;
54
55	/* input layer checks if event is redundant */
56	input_report_switch(button->input, SW_TABLET_MODE, !state);
57	input_sync(button->input);
58	return 0;
59}
60
61static void ebook_switch_notify(struct acpi_device *device, u32 event)
62{
63	switch (event) {
64	case ACPI_FIXED_HARDWARE_EVENT:
65	case XO15_EBOOK_NOTIFY_STATUS:
66		ebook_send_state(device);
67		break;
68	default:
69		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
70				  "Unsupported event [0x%x]\n", event));
71		break;
72	}
73}
74
75#ifdef CONFIG_PM_SLEEP
76static int ebook_switch_resume(struct device *dev)
77{
78	return ebook_send_state(to_acpi_device(dev));
79}
80#endif
81
82static SIMPLE_DEV_PM_OPS(ebook_switch_pm, NULL, ebook_switch_resume);
83
84static int ebook_switch_add(struct acpi_device *device)
85{
86	struct ebook_switch *button;
87	struct input_dev *input;
88	const char *hid = acpi_device_hid(device);
89	char *name, *class;
90	int error;
91
92	button = kzalloc(sizeof(struct ebook_switch), GFP_KERNEL);
93	if (!button)
94		return -ENOMEM;
95
96	device->driver_data = button;
97
98	button->input = input = input_allocate_device();
99	if (!input) {
100		error = -ENOMEM;
101		goto err_free_button;
102	}
103
104	name = acpi_device_name(device);
105	class = acpi_device_class(device);
106
107	if (strcmp(hid, XO15_EBOOK_HID)) {
108		pr_err("Unsupported hid [%s]\n", hid);
109		error = -ENODEV;
110		goto err_free_input;
111	}
112
113	strcpy(name, XO15_EBOOK_DEVICE_NAME);
114	sprintf(class, "%s/%s", XO15_EBOOK_CLASS, XO15_EBOOK_SUBCLASS);
115
116	snprintf(button->phys, sizeof(button->phys), "%s/button/input0", hid);
117
118	input->name = name;
119	input->phys = button->phys;
120	input->id.bustype = BUS_HOST;
121	input->dev.parent = &device->dev;
122
123	input->evbit[0] = BIT_MASK(EV_SW);
124	set_bit(SW_TABLET_MODE, input->swbit);
125
126	error = input_register_device(input);
127	if (error)
128		goto err_free_input;
129
130	ebook_send_state(device);
131
132	if (device->wakeup.flags.valid) {
133		/* Button's GPE is run-wake GPE */
134		acpi_enable_gpe(device->wakeup.gpe_device,
135				device->wakeup.gpe_number);
136		device_set_wakeup_enable(&device->dev, true);
137	}
138
139	return 0;
140
141 err_free_input:
142	input_free_device(input);
143 err_free_button:
144	kfree(button);
145	return error;
146}
147
148static int ebook_switch_remove(struct acpi_device *device)
149{
150	struct ebook_switch *button = acpi_driver_data(device);
151
152	input_unregister_device(button->input);
153	kfree(button);
154	return 0;
155}
156
157static struct acpi_driver xo15_ebook_driver = {
158	.name = MODULE_NAME,
159	.class = XO15_EBOOK_CLASS,
160	.ids = ebook_device_ids,
161	.ops = {
162		.add = ebook_switch_add,
163		.remove = ebook_switch_remove,
164		.notify = ebook_switch_notify,
165	},
166	.drv.pm = &ebook_switch_pm,
167};
168module_acpi_driver(xo15_ebook_driver);
169