xref: /linux/drivers/input/misc/atlas_btns.c (revision ffd01c3bcc1af4d8c3e7949152af0d9fe3d1fda5)
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/platform_device.h>
18 #include <linux/uaccess.h>
19 
20 #define ACPI_ATLAS_NAME		"Atlas ACPI"
21 #define ACPI_ATLAS_CLASS	"Atlas"
22 
23 static unsigned short atlas_keymap[16];
24 static struct input_dev *input_dev;
25 
26 /* button handling code */
27 static acpi_status acpi_atlas_button_setup(acpi_handle region_handle,
28 		    u32 function, void *handler_context, void **return_context)
29 {
30 	*return_context =
31 		(function != ACPI_REGION_DEACTIVATE) ? handler_context : NULL;
32 
33 	return AE_OK;
34 }
35 
36 static acpi_status acpi_atlas_button_handler(u32 function,
37 		      acpi_physical_address address,
38 		      u32 bit_width, u64 *value,
39 		      void *handler_context, void *region_context)
40 {
41 	acpi_status status;
42 
43 	if (function == ACPI_WRITE) {
44 		int code = address & 0x0f;
45 		int key_down = !(address & 0x10);
46 
47 		input_event(input_dev, EV_MSC, MSC_SCAN, code);
48 		input_report_key(input_dev, atlas_keymap[code], key_down);
49 		input_sync(input_dev);
50 
51 		status = AE_OK;
52 	} else {
53 		pr_warn("shrugged on unexpected function: function=%x,address=%lx,value=%x\n",
54 			function, (unsigned long)address, (u32)*value);
55 		status = AE_BAD_PARAMETER;
56 	}
57 
58 	return status;
59 }
60 
61 static int atlas_acpi_button_probe(struct platform_device *pdev)
62 {
63 	struct acpi_device *device = ACPI_COMPANION(&pdev->dev);
64 	acpi_status status;
65 	int i;
66 	int err;
67 
68 	input_dev = input_allocate_device();
69 	if (!input_dev) {
70 		pr_err("unable to allocate input device\n");
71 		return -ENOMEM;
72 	}
73 
74 	input_dev->name = "Atlas ACPI button driver";
75 	input_dev->phys = "ASIM0000/atlas/input0";
76 	input_dev->id.bustype = BUS_HOST;
77 	input_dev->keycode = atlas_keymap;
78 	input_dev->keycodesize = sizeof(unsigned short);
79 	input_dev->keycodemax = ARRAY_SIZE(atlas_keymap);
80 
81 	input_set_capability(input_dev, EV_MSC, MSC_SCAN);
82 	__set_bit(EV_KEY, input_dev->evbit);
83 	for (i = 0; i < ARRAY_SIZE(atlas_keymap); i++) {
84 		if (i < 9) {
85 			atlas_keymap[i] = KEY_F1 + i;
86 			__set_bit(KEY_F1 + i, input_dev->keybit);
87 		} else
88 			atlas_keymap[i] = KEY_RESERVED;
89 	}
90 
91 	err = input_register_device(input_dev);
92 	if (err) {
93 		pr_err("couldn't register input device\n");
94 		input_free_device(input_dev);
95 		return err;
96 	}
97 
98 	/* hookup button handler */
99 	status = acpi_install_address_space_handler(device->handle,
100 				0x81, &acpi_atlas_button_handler,
101 				&acpi_atlas_button_setup, device);
102 	if (ACPI_FAILURE(status)) {
103 		pr_err("error installing addr spc handler\n");
104 		input_unregister_device(input_dev);
105 		err = -EINVAL;
106 	}
107 
108 	return err;
109 }
110 
111 static void atlas_acpi_button_remove(struct platform_device *pdev)
112 {
113 	struct acpi_device *device = ACPI_COMPANION(&pdev->dev);
114 	acpi_status status;
115 
116 	status = acpi_remove_address_space_handler(device->handle,
117 				0x81, &acpi_atlas_button_handler);
118 	if (ACPI_FAILURE(status))
119 		pr_err("error removing addr spc handler\n");
120 
121 	input_unregister_device(input_dev);
122 }
123 
124 static const struct acpi_device_id atlas_device_ids[] = {
125 	{"ASIM0000", 0},
126 	{"", 0},
127 };
128 MODULE_DEVICE_TABLE(acpi, atlas_device_ids);
129 
130 static struct platform_driver atlas_acpi_driver = {
131 	.probe = atlas_acpi_button_probe,
132 	.remove = atlas_acpi_button_remove,
133 	.driver = {
134 		.name = ACPI_ATLAS_NAME,
135 		.acpi_match_table = atlas_device_ids,
136 	},
137 };
138 module_platform_driver(atlas_acpi_driver);
139 
140 MODULE_AUTHOR("Jaya Kumar");
141 MODULE_LICENSE("GPL");
142 MODULE_DESCRIPTION("Atlas button driver");
143 
144