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(input_dev, EV_MSC, MSC_SCAN, code);
47		input_report_key(input_dev, atlas_keymap[code], key_down);
48		input_sync(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(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(input_dev);
93		return err;
94	}
95
96	/* hookup button handler */
97	status = acpi_install_address_space_handler(device->handle,
98				0x81, &acpi_atlas_button_handler,
99				&acpi_atlas_button_setup, 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->handle,
114				0x81, &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