Two LED triggers are added into hci_dev: tx_led and rx_led. Upon ACL/SCO
packets available in tx or rx, the LEDs will blink.

For each hci registration, two triggers are added into LED subsystem:
[hdev->name]-tx and [hdev-name]-rx.
Refer to Documentation/leds/leds-class.txt for usage.

Verified on HiKey 96boards, which uses HiSilicon hi6220 SoC and TI
WL1835 WiFi/BT combo chip.

Signed-off-by: Guodong Xu <redacted>
---
 include/net/bluetooth/hci_core.h |  1 +
 net/bluetooth/hci_core.c         |  6 ++++++
 net/bluetooth/leds.c             | 17 +++++++++++++++++
 net/bluetooth/leds.h             |  2 ++
 4 files changed, 26 insertions(+)

diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index dc71473..37b8dd9 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h

@@ -398,6 +398,7 @@ struct hci_dev {
        bdaddr_t                rpa;

        struct led_trigger      *power_led;
+       struct led_trigger      *tx_led, *rx_led;

        int (*open)(struct hci_dev *hdev);
        int (*close)(struct hci_dev *hdev);

diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 45a9fc6..956dce1 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c

@@ -3833,6 +3833,7 @@ static void hci_sched_acl(struct hci_dev *hdev)
        if (!hci_conn_num(hdev, AMP_LINK) && hdev->dev_type == HCI_AMP)
                return;

+       hci_leds_blink_oneshot(hdev->tx_led);
        switch (hdev->flow_ctl_mode) {
        case HCI_FLOW_CTL_MODE_PACKET_BASED:
                hci_sched_acl_pkt(hdev);

@@ -3856,6 +3857,7 @@ static void hci_sched_sco(struct hci_dev *hdev)
        if (!hci_conn_num(hdev, SCO_LINK))
                return;

+       hci_leds_blink_oneshot(hdev->tx_led);
        while (hdev->sco_cnt && (conn = hci_low_sent(hdev, SCO_LINK, &quote))) {
                while (quote-- && (skb = skb_dequeue(&conn->data_q))) {
                        BT_DBG("skb %p len %d", skb, skb->len);

@@ -3879,6 +3881,7 @@ static void hci_sched_esco(struct hci_dev *hdev)
        if (!hci_conn_num(hdev, ESCO_LINK))
                return;

+       hci_leds_blink_oneshot(hdev->tx_led);
        while (hdev->sco_cnt && (conn = hci_low_sent(hdev, ESCO_LINK,
                                                     &quote))) {
                while (quote-- && (skb = skb_dequeue(&conn->data_q))) {

@@ -3911,6 +3914,7 @@ static void hci_sched_le(struct hci_dev *hdev)
                        hci_link_tx_to(hdev, LE_LINK);
        }

+       hci_leds_blink_oneshot(hdev->tx_led);
        cnt = hdev->le_pkts ? hdev->le_cnt : hdev->acl_cnt;
        tmp = cnt;
        while (cnt && (chan = hci_chan_sent(hdev, LE_LINK, &quote))) {

@@ -3990,6 +3994,7 @@ static void hci_acldata_packet(struct hci_dev *hdev, struct sk_buff *skb)

        if (conn) {
                hci_conn_enter_active_mode(conn, BT_POWER_FORCE_ACTIVE_OFF);
+               hci_leds_blink_oneshot(hdev->rx_led);

                /* Send to upper protocol */
                l2cap_recv_acldata(conn, skb, flags);

@@ -4022,6 +4027,7 @@ static void hci_scodata_packet(struct hci_dev *hdev, struct sk_buff *skb)
        hci_dev_unlock(hdev);

        if (conn) {
+               hci_leds_blink_oneshot(hdev->rx_led);
                /* Send to upper protocol */
                sco_recv_scodata(conn, skb);
                return;

diff --git a/net/bluetooth/leds.c b/net/bluetooth/leds.c
index 8319c84..ae10c5d 100644
--- a/net/bluetooth/leds.c
+++ b/net/bluetooth/leds.c

@@ -19,6 +19,8 @@ struct hci_basic_led_trigger {
 #define to_hci_basic_led_trigger(arg) container_of(arg, \
                        struct hci_basic_led_trigger, led_trigger)

+#define BLUETOOTH_BLINK_DELAY  50 /* ms */
+
 void hci_leds_update_powered(struct hci_dev *hdev, bool enabled)
 {
        if (hdev->power_led)

@@ -37,6 +39,17 @@ static void power_activate(struct led_classdev *led_cdev)
        led_trigger_event(led_cdev->trigger, powered ? LED_FULL : LED_OFF);
 }

+void hci_leds_blink_oneshot(struct led_trigger *trig)
+{
+       unsigned long led_delay = BLUETOOTH_BLINK_DELAY;
+
+       if (!trig)
+               return;
+
+       BT_DBG("led_trig %p", trig);
+       led_trigger_blink_oneshot(trig, &led_delay, &led_delay, 0);
+}
+
 static struct led_trigger *led_allocate_basic(struct hci_dev *hdev,
                        void (*activate)(struct led_classdev *led_cdev),
                        const char *name)

@@ -71,4 +84,8 @@ void hci_leds_init(struct hci_dev *hdev)
 {
        /* initialize power_led */
        hdev->power_led = led_allocate_basic(hdev, power_activate, "power");
+       /* initialize tx_led */
+       hdev->tx_led = led_allocate_basic(hdev, NULL, "tx");
+       /* initialize rx_led */
+       hdev->rx_led = led_allocate_basic(hdev, NULL, "rx");
 }

diff --git a/net/bluetooth/leds.h b/net/bluetooth/leds.h
index a9c4d6e..9b1cccd 100644
--- a/net/bluetooth/leds.h
+++ b/net/bluetooth/leds.h

@@ -9,8 +9,10 @@
 #if IS_ENABLED(CONFIG_BT_LEDS)
 void hci_leds_update_powered(struct hci_dev *hdev, bool enabled);
 void hci_leds_init(struct hci_dev *hdev);
+void hci_leds_blink_oneshot(struct led_trigger *trig);
 #else
 static inline void hci_leds_update_powered(struct hci_dev *hdev,
                                           bool enabled) {}
 static inline void hci_leds_init(struct hci_dev *hdev) {}
+static inline void hci_leds_blink_oneshot(struct led_trigger *trig) {}
 #endif
--

1.9.1