Bluetooth: hci_intel: Implement LPM suspend/resume
Add LPM PM suspend/resume/host_wake LPM functions.
A LPM transaction is composed with a LPM request and ack/response.
Host can send a LPM suspend/resume request to the controller which
should respond with a LPM ack.
If resume is requested by the controller (irq), host has to send a LPM
ack once resumed.
Signed-off-by: Loic Poulain <loic.poulain@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
diff --git a/drivers/bluetooth/hci_intel.c b/drivers/bluetooth/hci_intel.c
index 5d53185..2e15ca5 100644
--- a/drivers/bluetooth/hci_intel.c
+++ b/drivers/bluetooth/hci_intel.c
@@ -46,12 +46,17 @@
#define STATE_BOOTING 4
#define STATE_LPM_ENABLED 5
#define STATE_TX_ACTIVE 6
+#define STATE_SUSPENDED 7
+#define STATE_LPM_TRANSACTION 8
+#define HCI_LPM_WAKE_PKT 0xf0
#define HCI_LPM_PKT 0xf1
#define HCI_LPM_MAX_SIZE 10
#define HCI_LPM_HDR_SIZE HCI_EVENT_HDR_SIZE
#define LPM_OP_TX_NOTIFY 0x00
+#define LPM_OP_SUSPEND_ACK 0x02
+#define LPM_OP_RESUME_ACK 0x03
struct hci_lpm_pkt {
__u8 opcode;
@@ -129,6 +134,143 @@
return err;
}
+static int intel_wait_lpm_transaction(struct hci_uart *hu)
+{
+ struct intel_data *intel = hu->priv;
+ int err;
+
+ err = wait_on_bit_timeout(&intel->flags, STATE_LPM_TRANSACTION,
+ TASK_INTERRUPTIBLE,
+ msecs_to_jiffies(1000));
+
+ if (err == 1) {
+ bt_dev_err(hu->hdev, "LPM transaction interrupted");
+ return -EINTR;
+ }
+
+ if (err) {
+ bt_dev_err(hu->hdev, "LPM transaction timeout");
+ return -ETIMEDOUT;
+ }
+
+ return err;
+}
+
+static int intel_lpm_suspend(struct hci_uart *hu)
+{
+ static const u8 suspend[] = { 0x01, 0x01, 0x01 };
+ struct intel_data *intel = hu->priv;
+ struct sk_buff *skb;
+
+ if (!test_bit(STATE_LPM_ENABLED, &intel->flags) ||
+ test_bit(STATE_SUSPENDED, &intel->flags))
+ return 0;
+
+ if (test_bit(STATE_TX_ACTIVE, &intel->flags))
+ return -EAGAIN;
+
+ bt_dev_dbg(hu->hdev, "Suspending");
+
+ skb = bt_skb_alloc(sizeof(suspend), GFP_KERNEL);
+ if (!skb) {
+ bt_dev_err(hu->hdev, "Failed to alloc memory for LPM packet");
+ return -ENOMEM;
+ }
+
+ memcpy(skb_put(skb, sizeof(suspend)), suspend, sizeof(suspend));
+ bt_cb(skb)->pkt_type = HCI_LPM_PKT;
+
+ set_bit(STATE_LPM_TRANSACTION, &intel->flags);
+
+ skb_queue_tail(&intel->txq, skb);
+ hci_uart_tx_wakeup(hu);
+
+ intel_wait_lpm_transaction(hu);
+ /* Even in case of failure, continue and test the suspended flag */
+
+ clear_bit(STATE_LPM_TRANSACTION, &intel->flags);
+
+ if (!test_bit(STATE_SUSPENDED, &intel->flags)) {
+ bt_dev_err(hu->hdev, "Device suspend error");
+ return -EINVAL;
+ }
+
+ bt_dev_dbg(hu->hdev, "Suspended");
+
+ hci_uart_set_flow_control(hu, true);
+
+ return 0;
+}
+
+static int intel_lpm_resume(struct hci_uart *hu)
+{
+ struct intel_data *intel = hu->priv;
+ struct sk_buff *skb;
+
+ if (!test_bit(STATE_LPM_ENABLED, &intel->flags) ||
+ !test_bit(STATE_SUSPENDED, &intel->flags))
+ return 0;
+
+ bt_dev_dbg(hu->hdev, "Resuming");
+
+ hci_uart_set_flow_control(hu, false);
+
+ skb = bt_skb_alloc(0, GFP_KERNEL);
+ if (!skb) {
+ bt_dev_err(hu->hdev, "Failed to alloc memory for LPM packet");
+ return -ENOMEM;
+ }
+
+ bt_cb(skb)->pkt_type = HCI_LPM_WAKE_PKT;
+
+ set_bit(STATE_LPM_TRANSACTION, &intel->flags);
+
+ skb_queue_tail(&intel->txq, skb);
+ hci_uart_tx_wakeup(hu);
+
+ intel_wait_lpm_transaction(hu);
+ /* Even in case of failure, continue and test the suspended flag */
+
+ clear_bit(STATE_LPM_TRANSACTION, &intel->flags);
+
+ if (test_bit(STATE_SUSPENDED, &intel->flags)) {
+ bt_dev_err(hu->hdev, "Device resume error");
+ return -EINVAL;
+ }
+
+ bt_dev_dbg(hu->hdev, "Resumed");
+
+ return 0;
+}
+
+static int intel_lpm_host_wake(struct hci_uart *hu)
+{
+ static const u8 lpm_resume_ack[] = { LPM_OP_RESUME_ACK, 0x00 };
+ struct intel_data *intel = hu->priv;
+ struct sk_buff *skb;
+
+ hci_uart_set_flow_control(hu, false);
+
+ clear_bit(STATE_SUSPENDED, &intel->flags);
+
+ skb = bt_skb_alloc(sizeof(lpm_resume_ack), GFP_KERNEL);
+ if (!skb) {
+ bt_dev_err(hu->hdev, "Failed to alloc memory for LPM packet");
+ return -ENOMEM;
+ }
+
+ memcpy(skb_put(skb, sizeof(lpm_resume_ack)), lpm_resume_ack,
+ sizeof(lpm_resume_ack));
+ bt_cb(skb)->pkt_type = HCI_LPM_PKT;
+
+ skb_queue_tail(&intel->txq, skb);
+ hci_uart_tx_wakeup(hu);
+
+ bt_dev_dbg(hu->hdev, "Resumed by controller");
+
+ return 0;
+}
+
static irqreturn_t intel_irq(int irq, void *dev_id)
{
struct intel_device *idev = dev_id;
@@ -800,12 +942,28 @@
static int intel_recv_lpm(struct hci_dev *hdev, struct sk_buff *skb)
{
struct hci_lpm_pkt *lpm = (void *)skb->data;
+ struct hci_uart *hu = hci_get_drvdata(hdev);
+ struct intel_data *intel = hu->priv;
switch (lpm->opcode) {
case LPM_OP_TX_NOTIFY:
if (lpm->dlen)
intel_recv_lpm_notify(hdev, lpm->data[0]);
break;
+ case LPM_OP_SUSPEND_ACK:
+ set_bit(STATE_SUSPENDED, &intel->flags);
+ if (test_and_clear_bit(STATE_LPM_TRANSACTION, &intel->flags)) {
+ smp_mb__after_atomic();
+ wake_up_bit(&intel->flags, STATE_LPM_TRANSACTION);
+ }
+ break;
+ case LPM_OP_RESUME_ACK:
+ clear_bit(STATE_SUSPENDED, &intel->flags);
+ if (test_and_clear_bit(STATE_LPM_TRANSACTION, &intel->flags)) {
+ smp_mb__after_atomic();
+ wake_up_bit(&intel->flags, STATE_LPM_TRANSACTION);
+ }
+ break;
default:
bt_dev_err(hdev, "Unknown LPM opcode (%02x)", lpm->opcode);
break;