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 
22 static unsigned short atlas_keymap[16];
23 static struct input_dev *input_dev;
24 
25 /* button handling code */
acpi_atlas_button_setup(acpi_handle region_handle,u32 function,void * handler_context,void ** return_context)26 static 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 
acpi_atlas_button_handler(u32 function,acpi_physical_address address,u32 bit_width,u64 * value,void * handler_context,void * region_context)35 static 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 
atlas_acpi_button_add(struct acpi_device * device)60 static 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 
atlas_acpi_button_remove(struct acpi_device * device)109 static int 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 	return 0;
121 }
122 
123 static const struct acpi_device_id atlas_device_ids[] = {
124 	{"ASIM0000", 0},
125 	{"", 0},
126 };
127 MODULE_DEVICE_TABLE(acpi, atlas_device_ids);
128 
129 static struct acpi_driver atlas_acpi_driver = {
130 	.name	= ACPI_ATLAS_NAME,
131 	.class	= ACPI_ATLAS_CLASS,
132 	.owner	= THIS_MODULE,
133 	.ids	= atlas_device_ids,
134 	.ops	= {
135 		.add	= atlas_acpi_button_add,
136 		.remove	= atlas_acpi_button_remove,
137 	},
138 };
139 module_acpi_driver(atlas_acpi_driver);
140 
141 MODULE_AUTHOR("Jaya Kumar");
142 MODULE_LICENSE("GPL");
143 MODULE_DESCRIPTION("Atlas button driver");
144 
145