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 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
ebook_switch_remove(struct acpi_device * device)146 static 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
154 static 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 };
165 module_acpi_driver(xo15_ebook_driver);
166