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
29MODULE_DESCRIPTION("OLPC XO-1.5 ebook switch driver");
30MODULE_LICENSE("GPL");
31
32static const struct acpi_device_id ebook_device_ids[] = {
33	{ XO15_EBOOK_HID, 0 },
34	{ "", 0 },
35};
36MODULE_DEVICE_TABLE(acpi, ebook_device_ids);
37
38struct ebook_switch {
39	struct input_dev *input;
40	char phys[32];			/* for input device */
41};
42
43static int ebook_send_state(struct acpi_device *device)
44{
45	struct ebook_switch *button = acpi_driver_data(device);
46	unsigned long long state;
47	acpi_status status;
48
49	status = acpi_evaluate_integer(device->handle, "EBK", NULL, &state);
50	if (ACPI_FAILURE(status))
51		return -EIO;
52
53	/* input layer checks if event is redundant */
54	input_report_switch(button->input, SW_TABLET_MODE, !state);
55	input_sync(button->input);
56	return 0;
57}
58
59static void ebook_switch_notify(struct acpi_device *device, u32 event)
60{
61	switch (event) {
62	case ACPI_FIXED_HARDWARE_EVENT:
63	case XO15_EBOOK_NOTIFY_STATUS:
64		ebook_send_state(device);
65		break;
66	default:
67		acpi_handle_debug(device->handle,
68				  "Unsupported event [0x%x]\n", event);
69		break;
70	}
71}
72
73#ifdef CONFIG_PM_SLEEP
74static int ebook_switch_resume(struct device *dev)
75{
76	return ebook_send_state(to_acpi_device(dev));
77}
78#endif
79
80static SIMPLE_DEV_PM_OPS(ebook_switch_pm, NULL, ebook_switch_resume);
81
82static int ebook_switch_add(struct acpi_device *device)
83{
84	struct ebook_switch *button;
85	struct input_dev *input;
86	const char *hid = acpi_device_hid(device);
87	char *name, *class;
88	int error;
89
90	button = kzalloc(sizeof(struct ebook_switch), GFP_KERNEL);
91	if (!button)
92		return -ENOMEM;
93
94	device->driver_data = button;
95
96	button->input = input = input_allocate_device();
97	if (!input) {
98		error = -ENOMEM;
99		goto err_free_button;
100	}
101
102	name = acpi_device_name(device);
103	class = acpi_device_class(device);
104
105	if (strcmp(hid, XO15_EBOOK_HID)) {
106		pr_err("Unsupported hid [%s]\n", hid);
107		error = -ENODEV;
108		goto err_free_input;
109	}
110
111	strcpy(name, XO15_EBOOK_DEVICE_NAME);
112	sprintf(class, "%s/%s", XO15_EBOOK_CLASS, XO15_EBOOK_SUBCLASS);
113
114	snprintf(button->phys, sizeof(button->phys), "%s/button/input0", hid);
115
116	input->name = name;
117	input->phys = button->phys;
118	input->id.bustype = BUS_HOST;
119	input->dev.parent = &device->dev;
120
121	input->evbit[0] = BIT_MASK(EV_SW);
122	set_bit(SW_TABLET_MODE, input->swbit);
123
124	error = input_register_device(input);
125	if (error)
126		goto err_free_input;
127
128	ebook_send_state(device);
129
130	if (device->wakeup.flags.valid) {
131		/* Button's GPE is run-wake GPE */
132		acpi_enable_gpe(device->wakeup.gpe_device,
133				device->wakeup.gpe_number);
134		device_set_wakeup_enable(&device->dev, true);
135	}
136
137	return 0;
138
139 err_free_input:
140	input_free_device(input);
141 err_free_button:
142	kfree(button);
143	return error;
144}
145
146static void ebook_switch_remove(struct acpi_device *device)
147{
148	struct ebook_switch *button = acpi_driver_data(device);
149
150	input_unregister_device(button->input);
151	kfree(button);
152}
153
154static struct acpi_driver xo15_ebook_driver = {
155	.name = MODULE_NAME,
156	.class = XO15_EBOOK_CLASS,
157	.ids = ebook_device_ids,
158	.ops = {
159		.add = ebook_switch_add,
160		.remove = ebook_switch_remove,
161		.notify = ebook_switch_notify,
162	},
163	.drv.pm = &ebook_switch_pm,
164};
165module_acpi_driver(xo15_ebook_driver);
166