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 #include <linux/kernel.h>
21 #include <linux/module.h>
22 #include <linux/init.h>
23 #include <linux/types.h>
24 #include <acpi/acpi_bus.h>
25 #include <acpi/acpi_drivers.h>
26 
27 MODULE_AUTHOR("Jes Sorensen <Jes.Sorensen@gmail.com>");
28 MODULE_DESCRIPTION("Toshiba Laptop ACPI Bluetooth Enable Driver");
29 MODULE_LICENSE("GPL");
30 
31 
32 static int toshiba_bt_rfkill_add(struct acpi_device *device);
33 static int toshiba_bt_rfkill_remove(struct acpi_device *device, int type);
34 static void toshiba_bt_rfkill_notify(struct acpi_device *device, u32 event);
35 static int toshiba_bt_resume(struct acpi_device *device);
36 
37 static const struct acpi_device_id bt_device_ids[] = {
38 	{ "TOS6205", 0},
39 	{ "", 0},
40 };
41 MODULE_DEVICE_TABLE(acpi, bt_device_ids);
42 
43 static struct acpi_driver toshiba_bt_rfkill_driver = {
44 	.name =		"Toshiba BT",
45 	.class =	"Toshiba",
46 	.ids =		bt_device_ids,
47 	.ops =		{
48 				.add =		toshiba_bt_rfkill_add,
49 				.remove =	toshiba_bt_rfkill_remove,
50 				.notify =	toshiba_bt_rfkill_notify,
51 				.resume =	toshiba_bt_resume,
52 			},
53 	.owner = 	THIS_MODULE,
54 };
55 
56 
57 static int toshiba_bluetooth_enable(acpi_handle handle)
58 {
59 	acpi_status res1, res2;
60 	u64 result;
61 
62 	/*
63 	 * Query ACPI to verify RFKill switch is set to 'on'.
64 	 * If not, we return silently, no need to report it as
65 	 * an error.
66 	 */
67 	res1 = acpi_evaluate_integer(handle, "BTST", NULL, &result);
68 	if (ACPI_FAILURE(res1))
69 		return res1;
70 	if (!(result & 0x01))
71 		return 0;
72 
73 	printk(KERN_INFO "toshiba_bluetooth: Re-enabling Toshiba Bluetooth\n");
74 	res1 = acpi_evaluate_object(handle, "AUSB", NULL, NULL);
75 	res2 = acpi_evaluate_object(handle, "BTPO", NULL, NULL);
76 	if (!ACPI_FAILURE(res1) || !ACPI_FAILURE(res2))
77 		return 0;
78 
79 	printk(KERN_WARNING "toshiba_bluetooth: Failed to re-enable "
80 	       "Toshiba Bluetooth\n");
81 
82 	return -ENODEV;
83 }
84 
85 static void toshiba_bt_rfkill_notify(struct acpi_device *device, u32 event)
86 {
87 	toshiba_bluetooth_enable(device->handle);
88 }
89 
90 static int toshiba_bt_resume(struct acpi_device *device)
91 {
92 	return toshiba_bluetooth_enable(device->handle);
93 }
94 
95 static int toshiba_bt_rfkill_add(struct acpi_device *device)
96 {
97 	acpi_status status;
98 	u64 bt_present;
99 	int result = -ENODEV;
100 
101 	/*
102 	 * Some Toshiba laptops may have a fake TOS6205 device in
103 	 * their ACPI BIOS, so query the _STA method to see if there
104 	 * is really anything there, before trying to enable it.
105 	 */
106 	status = acpi_evaluate_integer(device->handle, "_STA", NULL,
107 				       &bt_present);
108 
109 	if (!ACPI_FAILURE(status) && bt_present) {
110 		printk(KERN_INFO "Detected Toshiba ACPI Bluetooth device - "
111 		      "installing RFKill handler\n");
112 		result = toshiba_bluetooth_enable(device->handle);
113 	}
114 
115 	return result;
116 }
117 
118 static int __init toshiba_bt_rfkill_init(void)
119 {
120 	int result;
121 
122 	result = acpi_bus_register_driver(&toshiba_bt_rfkill_driver);
123 	if (result < 0) {
124 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
125 				  "Error registering driver\n"));
126 		return result;
127 	}
128 
129 	return 0;
130 }
131 
132 static int toshiba_bt_rfkill_remove(struct acpi_device *device, int type)
133 {
134 	/* clean up */
135 	return 0;
136 }
137 
138 static void __exit toshiba_bt_rfkill_exit(void)
139 {
140 	acpi_bus_unregister_driver(&toshiba_bt_rfkill_driver);
141 }
142 
143 module_init(toshiba_bt_rfkill_init);
144 module_exit(toshiba_bt_rfkill_exit);
145