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
29 MODULE_DESCRIPTION("OLPC XO-1.5 ebook switch driver");
30 MODULE_LICENSE("GPL");
31
32 static const struct acpi_device_id ebook_device_ids[] = {
33 { XO15_EBOOK_HID, 0 },
34 { "", 0 },
35 };
36 MODULE_DEVICE_TABLE(acpi, ebook_device_ids);
37
38 struct ebook_switch {
39 struct input_dev *input;
40 char phys[32]; /* for input device */
41 };
42
ebook_send_state(struct acpi_device * device)43 static 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
ebook_switch_notify(struct acpi_device * device,u32 event)59 static 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
ebook_switch_resume(struct device * dev)74 static int ebook_switch_resume(struct device *dev)
75 {
76 return ebook_send_state(to_acpi_device(dev));
77 }
78 #endif
79
80 static SIMPLE_DEV_PM_OPS(ebook_switch_pm, NULL, ebook_switch_resume);
81
ebook_switch_add(struct acpi_device * device)82 static int ebook_switch_add(struct acpi_device *device)
83 {
84 const struct acpi_device_id *id;
85 struct ebook_switch *button;
86 struct input_dev *input;
87 int error;
88
89 button = kzalloc(sizeof(struct ebook_switch), GFP_KERNEL);
90 if (!button)
91 return -ENOMEM;
92
93 device->driver_data = button;
94
95 button->input = input = input_allocate_device();
96 if (!input) {
97 error = -ENOMEM;
98 goto err_free_button;
99 }
100
101 id = acpi_match_acpi_device(ebook_device_ids, device);
102 if (!id) {
103 dev_err(&device->dev, "Unsupported hid\n");
104 error = -ENODEV;
105 goto err_free_input;
106 }
107
108 strscpy(acpi_device_name(device), XO15_EBOOK_DEVICE_NAME);
109 strscpy(acpi_device_class(device), XO15_EBOOK_CLASS "/" XO15_EBOOK_SUBCLASS);
110
111 snprintf(button->phys, sizeof(button->phys), "%s/button/input0", id->id);
112
113 input->name = acpi_device_name(device);
114 input->phys = button->phys;
115 input->id.bustype = BUS_HOST;
116 input->dev.parent = &device->dev;
117
118 input->evbit[0] = BIT_MASK(EV_SW);
119 set_bit(SW_TABLET_MODE, input->swbit);
120
121 error = input_register_device(input);
122 if (error)
123 goto err_free_input;
124
125 ebook_send_state(device);
126
127 if (device->wakeup.flags.valid) {
128 /* Button's GPE is run-wake GPE */
129 acpi_enable_gpe(device->wakeup.gpe_device,
130 device->wakeup.gpe_number);
131 device_set_wakeup_enable(&device->dev, true);
132 }
133
134 return 0;
135
136 err_free_input:
137 input_free_device(input);
138 err_free_button:
139 kfree(button);
140 return error;
141 }
142
ebook_switch_remove(struct acpi_device * device)143 static void ebook_switch_remove(struct acpi_device *device)
144 {
145 struct ebook_switch *button = acpi_driver_data(device);
146
147 input_unregister_device(button->input);
148 kfree(button);
149 }
150
151 static struct acpi_driver xo15_ebook_driver = {
152 .name = MODULE_NAME,
153 .class = XO15_EBOOK_CLASS,
154 .ids = ebook_device_ids,
155 .ops = {
156 .add = ebook_switch_add,
157 .remove = ebook_switch_remove,
158 .notify = ebook_switch_notify,
159 },
160 .drv.pm = &ebook_switch_pm,
161 };
162 module_acpi_driver(xo15_ebook_driver);
163