1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * atlas_btns.c - Atlas Wallmount Touchscreen ACPI Extras
4 *
5 * Copyright (C) 2006 Jaya Kumar
6 * Based on Toshiba ACPI by John Belmonte and ASUS ACPI
7 * This work was sponsored by CIS(M) Sdn Bhd.
8 */
9
10#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11
12#include <linux/kernel.h>
13#include <linux/module.h>
14#include <linux/input.h>
15#include <linux/types.h>
16#include <linux/acpi.h>
17#include <linux/uaccess.h>
18
19#define ACPI_ATLAS_NAME "Atlas ACPI"
20#define ACPI_ATLAS_CLASS "Atlas"
21
22static unsigned short atlas_keymap[16];
23static struct input_dev *input_dev;
24
25/* button handling code */
26static acpi_status acpi_atlas_button_setup(acpi_handle region_handle,
27 u32 function, void *handler_context, void **return_context)
28{
29 *return_context =
30 (function != ACPI_REGION_DEACTIVATE) ? handler_context : NULL;
31
32 return AE_OK;
33}
34
35static acpi_status acpi_atlas_button_handler(u32 function,
36 acpi_physical_address address,
37 u32 bit_width, u64 *value,
38 void *handler_context, void *region_context)
39{
40 acpi_status status;
41
42 if (function == ACPI_WRITE) {
43 int code = address & 0x0f;
44 int key_down = !(address & 0x10);
45
46 input_event(dev: input_dev, EV_MSC, MSC_SCAN, value: code);
47 input_report_key(dev: input_dev, code: atlas_keymap[code], value: key_down);
48 input_sync(dev: input_dev);
49
50 status = AE_OK;
51 } else {
52 pr_warn("shrugged on unexpected function: function=%x,address=%lx,value=%x\n",
53 function, (unsigned long)address, (u32)*value);
54 status = AE_BAD_PARAMETER;
55 }
56
57 return status;
58}
59
60static int atlas_acpi_button_add(struct acpi_device *device)
61{
62 acpi_status status;
63 int i;
64 int err;
65
66 input_dev = input_allocate_device();
67 if (!input_dev) {
68 pr_err("unable to allocate input device\n");
69 return -ENOMEM;
70 }
71
72 input_dev->name = "Atlas ACPI button driver";
73 input_dev->phys = "ASIM0000/atlas/input0";
74 input_dev->id.bustype = BUS_HOST;
75 input_dev->keycode = atlas_keymap;
76 input_dev->keycodesize = sizeof(unsigned short);
77 input_dev->keycodemax = ARRAY_SIZE(atlas_keymap);
78
79 input_set_capability(dev: input_dev, EV_MSC, MSC_SCAN);
80 __set_bit(EV_KEY, input_dev->evbit);
81 for (i = 0; i < ARRAY_SIZE(atlas_keymap); i++) {
82 if (i < 9) {
83 atlas_keymap[i] = KEY_F1 + i;
84 __set_bit(KEY_F1 + i, input_dev->keybit);
85 } else
86 atlas_keymap[i] = KEY_RESERVED;
87 }
88
89 err = input_register_device(input_dev);
90 if (err) {
91 pr_err("couldn't register input device\n");
92 input_free_device(dev: input_dev);
93 return err;
94 }
95
96 /* hookup button handler */
97 status = acpi_install_address_space_handler(device: device->handle,
98 space_id: 0x81, handler: &acpi_atlas_button_handler,
99 setup: &acpi_atlas_button_setup, context: device);
100 if (ACPI_FAILURE(status)) {
101 pr_err("error installing addr spc handler\n");
102 input_unregister_device(input_dev);
103 err = -EINVAL;
104 }
105
106 return err;
107}
108
109static void atlas_acpi_button_remove(struct acpi_device *device)
110{
111 acpi_status status;
112
113 status = acpi_remove_address_space_handler(device: device->handle,
114 space_id: 0x81, handler: &acpi_atlas_button_handler);
115 if (ACPI_FAILURE(status))
116 pr_err("error removing addr spc handler\n");
117
118 input_unregister_device(input_dev);
119}
120
121static const struct acpi_device_id atlas_device_ids[] = {
122 {"ASIM0000", 0},
123 {"", 0},
124};
125MODULE_DEVICE_TABLE(acpi, atlas_device_ids);
126
127static struct acpi_driver atlas_acpi_driver = {
128 .name = ACPI_ATLAS_NAME,
129 .class = ACPI_ATLAS_CLASS,
130 .owner = THIS_MODULE,
131 .ids = atlas_device_ids,
132 .ops = {
133 .add = atlas_acpi_button_add,
134 .remove = atlas_acpi_button_remove,
135 },
136};
137module_acpi_driver(atlas_acpi_driver);
138
139MODULE_AUTHOR("Jaya Kumar");
140MODULE_LICENSE("GPL");
141MODULE_DESCRIPTION("Atlas button driver");
142
143

source code of linux/drivers/input/misc/atlas_btns.c