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);
36 static void toshiba_bt_rfkill_notify(struct acpi_device *device, u32 event);
37 
38 static const struct acpi_device_id bt_device_ids[] = {
39 	{ "TOS6205", 0},
40 	{ "", 0},
41 };
42 MODULE_DEVICE_TABLE(acpi, bt_device_ids);
43 
44 #ifdef CONFIG_PM_SLEEP
45 static int toshiba_bt_resume(struct device *dev);
46 #endif
47 static SIMPLE_DEV_PM_OPS(toshiba_bt_pm, NULL, toshiba_bt_resume);
48 
49 static struct acpi_driver toshiba_bt_rfkill_driver = {
50 	.name =		"Toshiba BT",
51 	.class =	"Toshiba",
52 	.ids =		bt_device_ids,
53 	.ops =		{
54 				.add =		toshiba_bt_rfkill_add,
55 				.remove =	toshiba_bt_rfkill_remove,
56 				.notify =	toshiba_bt_rfkill_notify,
57 			},
58 	.owner = 	THIS_MODULE,
59 	.drv.pm =	&toshiba_bt_pm,
60 };
61 
62 
63 static int toshiba_bluetooth_enable(acpi_handle handle)
64 {
65 	acpi_status res1, res2;
66 	u64 result;
67 
68 	/*
69 	 * Query ACPI to verify RFKill switch is set to 'on'.
70 	 * If not, we return silently, no need to report it as
71 	 * an error.
72 	 */
73 	res1 = acpi_evaluate_integer(handle, "BTST", NULL, &result);
74 	if (ACPI_FAILURE(res1))
75 		return res1;
76 	if (!(result & 0x01))
77 		return 0;
78 
79 	pr_info("Re-enabling Toshiba Bluetooth\n");
80 	res1 = acpi_evaluate_object(handle, "AUSB", NULL, NULL);
81 	res2 = acpi_evaluate_object(handle, "BTPO", NULL, NULL);
82 	if (!ACPI_FAILURE(res1) || !ACPI_FAILURE(res2))
83 		return 0;
84 
85 	pr_warn("Failed to re-enable Toshiba Bluetooth\n");
86 
87 	return -ENODEV;
88 }
89 
90 static void toshiba_bt_rfkill_notify(struct acpi_device *device, u32 event)
91 {
92 	toshiba_bluetooth_enable(device->handle);
93 }
94 
95 #ifdef CONFIG_PM_SLEEP
96 static int toshiba_bt_resume(struct device *dev)
97 {
98 	return toshiba_bluetooth_enable(to_acpi_device(dev)->handle);
99 }
100 #endif
101 
102 static int toshiba_bt_rfkill_add(struct acpi_device *device)
103 {
104 	acpi_status status;
105 	u64 bt_present;
106 	int result = -ENODEV;
107 
108 	/*
109 	 * Some Toshiba laptops may have a fake TOS6205 device in
110 	 * their ACPI BIOS, so query the _STA method to see if there
111 	 * is really anything there, before trying to enable it.
112 	 */
113 	status = acpi_evaluate_integer(device->handle, "_STA", NULL,
114 				       &bt_present);
115 
116 	if (!ACPI_FAILURE(status) && bt_present) {
117 		pr_info("Detected Toshiba ACPI Bluetooth device - "
118 			"installing RFKill handler\n");
119 		result = toshiba_bluetooth_enable(device->handle);
120 	}
121 
122 	return result;
123 }
124 
125 static int toshiba_bt_rfkill_remove(struct acpi_device *device)
126 {
127 	/* clean up */
128 	return 0;
129 }
130 
131 module_acpi_driver(toshiba_bt_rfkill_driver);
132