Bluetooth: hci_h5: Add runtime suspend

This patch allows the controller to suspend after a short period of
inactivity.

Signed-off-by: Archie Pusaka <apusaka@chromium.org>
Reviewed-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
Reviewed-by: Hilda Wu <hildawu@realtek.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

drivers/bluetooth/hci_h5.c

@@ -12,6 +12,7 @@
 #include <linux/kernel.h>
 #include <linux/mod_devicetable.h>
 #include <linux/of_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/serdev.h>
 #include <linux/skbuff.h>
 
@@ -21,6 +22,8 @@
 #include "btrtl.h"
 #include "hci_uart.h"
 
+#define SUSPEND_TIMEOUT_MS	6000
+
 #define HCI_3WIRE_ACK_PKT	0
 #define HCI_3WIRE_LINK_PKT	15
 
@@ -584,6 +587,10 @@ static int h5_recv(struct hci_uart *hu, const void *data, int count)
 		count -= processed;
 	}
 
+	pm_runtime_get(&hu->serdev->dev);
+	pm_runtime_mark_last_busy(&hu->serdev->dev);
+	pm_runtime_put_autosuspend(&hu->serdev->dev);
+
 	return 0;
 }
 
@@ -620,6 +627,10 @@ static int h5_enqueue(struct hci_uart *hu, struct sk_buff *skb)
 		break;
 	}
 
+	pm_runtime_get_sync(&hu->serdev->dev);
+	pm_runtime_mark_last_busy(&hu->serdev->dev);
+	pm_runtime_put_autosuspend(&hu->serdev->dev);
+
 	return 0;
 }
 
@@ -951,6 +962,12 @@ static void h5_btrtl_open(struct h5 *h5)
 	serdev_device_set_parity(h5->hu->serdev, SERDEV_PARITY_EVEN);
 	serdev_device_set_baudrate(h5->hu->serdev, 115200);
 
+	pm_runtime_set_active(&h5->hu->serdev->dev);
+	pm_runtime_use_autosuspend(&h5->hu->serdev->dev);
+	pm_runtime_set_autosuspend_delay(&h5->hu->serdev->dev,
+					 SUSPEND_TIMEOUT_MS);
+	pm_runtime_enable(&h5->hu->serdev->dev);
+
 	/* The controller needs up to 500ms to wakeup */
 	gpiod_set_value_cansleep(h5->enable_gpio, 1);
 	gpiod_set_value_cansleep(h5->device_wake_gpio, 1);
@@ -959,6 +976,8 @@ static void h5_btrtl_open(struct h5 *h5)
 
 static void h5_btrtl_close(struct h5 *h5)
 {
+	pm_runtime_disable(&h5->hu->serdev->dev);
+
 	gpiod_set_value_cansleep(h5->device_wake_gpio, 0);
 	gpiod_set_value_cansleep(h5->enable_gpio, 0);
 }
@@ -1066,6 +1085,7 @@ MODULE_DEVICE_TABLE(acpi, h5_acpi_match);
 
 static const struct dev_pm_ops h5_serdev_pm_ops = {
 	SET_SYSTEM_SLEEP_PM_OPS(h5_serdev_suspend, h5_serdev_resume)
+	SET_RUNTIME_PM_OPS(h5_serdev_suspend, h5_serdev_resume, NULL)
 };
 
 static const struct of_device_id rtl_bluetooth_of_match[] = {