1 /*
2  * Toshiba Bluetooth Enable Driver
3  *
4  * Copyright (C) 2009 Jes Sorensen <Jes.Sorensen@gmail.com>
5  *
6  * Thanks to Matthew Garrett for background info on ACPI innards which
7  * normal people aren't meant to understand :-)
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License version 2 as
11  * published by the Free Software Foundation.
12  *
13  * Note the Toshiba Bluetooth RFKill switch seems to be a strange
14  * fish. It only provides a BT event when the switch is flipped to
15  * the 'on' position. When flipping it to 'off', the USB device is
16  * simply pulled away underneath us, without any BT event being
17  * delivered.
18  */
19 
20 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
21 
22 #include <linux/kernel.h>
23 #include <linux/module.h>
24 #include <linux/init.h>
25 #include <linux/types.h>
26 #include <acpi/acpi_bus.h>
27 #include <acpi/acpi_drivers.h>
28 
29 MODULE_AUTHOR("Jes Sorensen <Jes.Sorensen@gmail.com>");
30 MODULE_DESCRIPTION("Toshiba Laptop ACPI Bluetooth Enable Driver");
31 MODULE_LICENSE("GPL");
32 
33 
34 static int toshiba_bt_rfkill_add(struct acpi_device *device);
35 static int toshiba_bt_rfkill_remove(struct acpi_device *device, int type);
36 static void toshiba_bt_rfkill_notify(struct acpi_device *device, u32 event);
37 static int toshiba_bt_resume(struct acpi_device *device);
38 
39 static const struct acpi_device_id bt_device_ids[] = {
40 	{ "TOS6205", 0},
41 	{ "", 0},
42 };
43 MODULE_DEVICE_TABLE(acpi, bt_device_ids);
44 
45 static struct acpi_driver toshiba_bt_rfkill_driver = {
46 	.name =		"Toshiba BT",
47 	.class =	"Toshiba",
48 	.ids =		bt_device_ids,
49 	.ops =		{
50 				.add =		toshiba_bt_rfkill_add,
51 				.remove =	toshiba_bt_rfkill_remove,
52 				.notify =	toshiba_bt_rfkill_notify,
53 				.resume =	toshiba_bt_resume,
54 			},
55 	.owner = 	THIS_MODULE,
56 };
57 
58 
59 static int toshiba_bluetooth_enable(acpi_handle handle)
60 {
61 	acpi_status res1, res2;
62 	u64 result;
63 
64 	/*
65 	 * Query ACPI to verify RFKill switch is set to 'on'.
66 	 * If not, we return silently, no need to report it as
67 	 * an error.
68 	 */
69 	res1 = acpi_evaluate_integer(handle, "BTST", NULL, &result);
70 	if (ACPI_FAILURE(res1))
71 		return res1;
72 	if (!(result & 0x01))
73 		return 0;
74 
75 	pr_info("Re-enabling Toshiba Bluetooth\n");
76 	res1 = acpi_evaluate_object(handle, "AUSB", NULL, NULL);
77 	res2 = acpi_evaluate_object(handle, "BTPO", NULL, NULL);
78 	if (!ACPI_FAILURE(res1) || !ACPI_FAILURE(res2))
79 		return 0;
80 
81 	pr_warn("Failed to re-enable Toshiba Bluetooth\n");
82 
83 	return -ENODEV;
84 }
85 
86 static void toshiba_bt_rfkill_notify(struct acpi_device *device, u32 event)
87 {
88 	toshiba_bluetooth_enable(device->handle);
89 }
90 
91 static int toshiba_bt_resume(struct acpi_device *device)
92 {
93 	return toshiba_bluetooth_enable(device->handle);
94 }
95 
96 static int toshiba_bt_rfkill_add(struct acpi_device *device)
97 {
98 	acpi_status status;
99 	u64 bt_present;
100 	int result = -ENODEV;
101 
102 	/*
103 	 * Some Toshiba laptops may have a fake TOS6205 device in
104 	 * their ACPI BIOS, so query the _STA method to see if there
105 	 * is really anything there, before trying to enable it.
106 	 */
107 	status = acpi_evaluate_integer(device->handle, "_STA", NULL,
108 				       &bt_present);
109 
110 	if (!ACPI_FAILURE(status) && bt_present) {
111 		pr_info("Detected Toshiba ACPI Bluetooth device - "
112 			"installing RFKill handler\n");
113 		result = toshiba_bluetooth_enable(device->handle);
114 	}
115 
116 	return result;
117 }
118 
119 static int __init toshiba_bt_rfkill_init(void)
120 {
121 	int result;
122 
123 	result = acpi_bus_register_driver(&toshiba_bt_rfkill_driver);
124 	if (result < 0) {
125 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
126 				  "Error registering driver\n"));
127 		return result;
128 	}
129 
130 	return 0;
131 }
132 
133 static int toshiba_bt_rfkill_remove(struct acpi_device *device, int type)
134 {
135 	/* clean up */
136 	return 0;
137 }
138 
139 static void __exit toshiba_bt_rfkill_exit(void)
140 {
141 	acpi_bus_unregister_driver(&toshiba_bt_rfkill_driver);
142 }
143 
144 module_init(toshiba_bt_rfkill_init);
145 module_exit(toshiba_bt_rfkill_exit);
146