Bluetooth: add LED trigger for indicating HCI is powered up

Add support for LED triggers to the Bluetooth subsystem and add kernel
config symbol BT_LEDS for it.

For now one trigger for indicating "HCI is powered up" is supported.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

1 files changed, 80 insertions, 0 deletions

diff --git a/net/bluetooth/leds.c b/net/bluetooth/leds.c
new file mode 100644
index 000000000000..ded7c88eaccc
--- /dev/null
+++ b/net/bluetooth/leds.c
@@ -0,0 +1,80 @@
+/*
+ * Copyright 2015, Heiner Kallweit <hkallweit1@gmail.com>
+ *
+ * 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.
+ */
+
+#include <net/bluetooth/bluetooth.h>
+#include <net/bluetooth/hci_core.h>
+
+#include "leds.h"
+
+struct hci_basic_led_trigger {
+        struct led_trigger      led_trigger;
+        struct hci_dev          *hdev;
+};
+
+#define to_hci_basic_led_trigger(arg) container_of(arg, \
+                        struct hci_basic_led_trigger, led_trigger)
+
+void hci_leds_update_powered(struct hci_dev *hdev, bool enabled)
+{
+        if (hdev->power_led)
+                led_trigger_event(hdev->power_led,
+                                  enabled ? LED_FULL : LED_OFF);
+}
+
+static void power_activate(struct led_classdev *led_cdev)
+{
+        struct hci_basic_led_trigger *htrig;
+        bool powered;
+
+        htrig = to_hci_basic_led_trigger(led_cdev->trigger);
+        powered = test_bit(HCI_UP, &htrig->hdev->flags);
+
+        led_trigger_event(led_cdev->trigger, powered ? LED_FULL : LED_OFF);
+}
+
+static struct led_trigger *led_allocate_basic(struct hci_dev *hdev,
+                        void (*activate)(struct led_classdev *led_cdev),
+                        const char *name)
+{
+        struct hci_basic_led_trigger *htrig;
+
+        htrig = devm_kzalloc(&hdev->dev, sizeof(*htrig), GFP_KERNEL);
+        if (!htrig)
+                return NULL;
+
+        htrig->hdev = hdev;
+        htrig->led_trigger.activate = activate;
+        htrig->led_trigger.name = devm_kasprintf(&hdev->dev, GFP_KERNEL,
+                                                 "%s-%s", hdev->name,
+                                                 name);
+        if (!htrig->led_trigger.name)
+                goto err_alloc;
+
+        if (led_trigger_register(&htrig->led_trigger))
+                goto err_register;
+
+        return &htrig->led_trigger;
+
+err_register:
+        devm_kfree(&hdev->dev, (void *)htrig->led_trigger.name);
+err_alloc:
+        devm_kfree(&hdev->dev, htrig);
+        return NULL;
+}
+
+void hci_leds_init(struct hci_dev *hdev)
+{
+        /* initialize power_led */
+        hdev->power_led = led_allocate_basic(hdev, power_activate, "power");
+}
+
+void hci_leds_exit(struct hci_dev *hdev)
+{
+        if (hdev->power_led)
+                led_trigger_unregister(hdev->power_led);
+}