Toshiba Bluetooth Enabling driver (RFKill handler v3)

This patch adds support for the ACPI events generated by the RFKill
switch on modern Toshiba laptops, and re-enables the Bluetooth USB
device when the switch is flipped back to the 'on' position.

The RFKill switch brute force pulls out the USB device when flipped to
'off', but it doesn't automatically re-enable it. Without this driver,
the Bluetooth is gone until after a reboot on my Portege R500.

Signed-off-by: Jes Sorensen <Jes.Sorensen@gmail.com>
Signed-off-by: Len Brown <len.brown@intel.com>

3 files changed, 160 insertions, 0 deletions

diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index 55ca39dea42e..8dd2b3a4c475 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -435,4 +435,19 @@ config ACPI_TOSHIBA
 
           If you have a legacy free Toshiba laptop (such as the Libretto L1
           series), say Y.
+
+config TOSHIBA_BT_RFKILL
+        tristate "Toshiba Bluetooth RFKill switch support"
+        depends on ACPI
+        ---help---
+          This driver adds support for Bluetooth events for the RFKill
+          switch on modern Toshiba laptops with full ACPI support and
+          an RFKill switch.
+
+          This driver handles RFKill events for the TOS6205 Bluetooth,
+          and re-enables it when the switch is set back to the 'on'
+          position.
+
+          If you have a modern Toshiba laptop with a Bluetooth and an
+          RFKill switch (such as the Portege R500), say Y.
 endif # X86_PLATFORM_DEVICES
diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
index d1c16210a512..394258bd77c0 100644
--- a/drivers/platform/x86/Makefile
+++ b/drivers/platform/x86/Makefile
@@ -21,3 +21,4 @@ obj-$(CONFIG_ACPI_WMI)		+= wmi.o
 obj-$(CONFIG_ACPI_ASUS)         += asus_acpi.o
 obj-$(CONFIG_TOPSTAR_LAPTOP)    += topstar-laptop.o
 obj-$(CONFIG_ACPI_TOSHIBA)      += toshiba_acpi.o
+obj-$(CONFIG_TOSHIBA_BT_RFKILL) += toshiba_bluetooth.o
diff --git a/drivers/platform/x86/toshiba_bluetooth.c b/drivers/platform/x86/toshiba_bluetooth.c
new file mode 100644
index 000000000000..a350418e87ea
--- /dev/null
+++ b/drivers/platform/x86/toshiba_bluetooth.c
@@ -0,0 +1,144 @@
+/*
+ * Toshiba Bluetooth Enable Driver
+ *
+ * Copyright (C) 2009 Jes Sorensen <Jes.Sorensen@gmail.com>
+ *
+ * Thanks to Matthew Garrett for background info on ACPI innards which
+ * normal people aren't meant to understand :-)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Note the Toshiba Bluetooth RFKill switch seems to be a strange
+ * fish. It only provides a BT event when the switch is flipped to
+ * the 'on' position. When flipping it to 'off', the USB device is
+ * simply pulled away underneath us, without any BT event being
+ * delivered.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <acpi/acpi_bus.h>
+#include <acpi/acpi_drivers.h>
+
+MODULE_AUTHOR("Jes Sorensen <Jes.Sorensen@gmail.com>");
+MODULE_DESCRIPTION("Toshiba Laptop ACPI Bluetooth Enable Driver");
+MODULE_LICENSE("GPL");
+
+
+static int toshiba_bt_rfkill_add(struct acpi_device *device);
+static int toshiba_bt_rfkill_remove(struct acpi_device *device, int type);
+static void toshiba_bt_rfkill_notify(struct acpi_device *device, u32 event);
+static int toshiba_bt_resume(struct acpi_device *device);
+
+static const struct acpi_device_id bt_device_ids[] = {
+        { "TOS6205", 0},
+        { "", 0},
+};
+MODULE_DEVICE_TABLE(acpi, bt_device_ids);
+
+static struct acpi_driver toshiba_bt_rfkill_driver = {
+        .name =         "Toshiba BT",
+        .class =        "Toshiba",
+        .ids =          bt_device_ids,
+        .ops =          {
+                                .add =          toshiba_bt_rfkill_add,
+                                .remove =       toshiba_bt_rfkill_remove,
+                                .notify =       toshiba_bt_rfkill_notify,
+                                .resume =       toshiba_bt_resume,
+                        },
+        .owner =        THIS_MODULE,
+};
+
+
+static int toshiba_bluetooth_enable(acpi_handle handle)
+{
+        acpi_status res1, res2;
+        acpi_integer result;
+
+        /*
+         * Query ACPI to verify RFKill switch is set to 'on'.
+         * If not, we return silently, no need to report it as
+         * an error.
+         */
+        res1 = acpi_evaluate_integer(handle, "BTST", NULL, &result);
+        if (ACPI_FAILURE(res1))
+                return res1;
+        if (!(result & 0x01))
+                return 0;
+
+        printk(KERN_INFO "toshiba_bluetooth: Re-enabling Toshiba Bluetooth\n");
+        res1 = acpi_evaluate_object(handle, "AUSB", NULL, NULL);
+        res2 = acpi_evaluate_object(handle, "BTPO", NULL, NULL);
+        if (!ACPI_FAILURE(res1) || !ACPI_FAILURE(res2))
+                return 0;
+
+        printk(KERN_WARNING "toshiba_bluetooth: Failed to re-enable "
+               "Toshiba Bluetooth\n");
+
+        return -ENODEV;
+}
+
+static void toshiba_bt_rfkill_notify(struct acpi_device *device, u32 event)
+{
+        toshiba_bluetooth_enable(device->handle);
+}
+
+static int toshiba_bt_resume(struct acpi_device *device)
+{
+        return toshiba_bluetooth_enable(device->handle);
+}
+
+static int toshiba_bt_rfkill_add(struct acpi_device *device)
+{
+        acpi_status status;
+        acpi_integer bt_present;
+        int result = -ENODEV;
+
+        /*
+         * Some Toshiba laptops may have a fake TOS6205 device in
+         * their ACPI BIOS, so query the _STA method to see if there
+         * is really anything there, before trying to enable it.
+         */
+        status = acpi_evaluate_integer(device->handle, "_STA", NULL,
+                                       &bt_present);
+
+        if (!ACPI_FAILURE(status) && bt_present) {
+                printk(KERN_INFO "Detected Toshiba ACPI Bluetooth device - "
+                      "installing RFKill handler\n");
+                result = toshiba_bluetooth_enable(device->handle);
+        }
+
+        return result;
+}
+
+static int __init toshiba_bt_rfkill_init(void)
+{
+        int result;
+
+        result = acpi_bus_register_driver(&toshiba_bt_rfkill_driver);
+        if (result < 0) {
+                ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+                                  "Error registering driver\n"));
+                return result;
+        }
+
+        return 0;
+}
+
+static int toshiba_bt_rfkill_remove(struct acpi_device *device, int type)
+{
+        /* clean up */
+        return 0;
+}
+
+static void __exit toshiba_bt_rfkill_exit(void)
+{
+        acpi_bus_unregister_driver(&toshiba_bt_rfkill_driver);
+}
+
+module_init(toshiba_bt_rfkill_init);
+module_exit(toshiba_bt_rfkill_exit);