[PATCH v1 8/9] serial: qcom-geni: Enable PM runtime for serial driver

[Praveen Talari]

Add Power Management (PM) runtime support to Qualcomm GENI
serial driver.

Introduce necessary callbacks and updates to ensure seamless
transitions between power states, enhancing overall power efficiency.

Signed-off-by: Praveen Talari <quic_ptalari@xxxxxxxxxxx>
---
 drivers/tty/serial/qcom_geni_serial.c | 35 ++++++++++++++++++++++-----
 1 file changed, 29 insertions(+), 6 deletions(-)

diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c
index 25d16ac3f406..9649297d4a9e 100644
--- a/drivers/tty/serial/qcom_geni_serial.c
+++ b/drivers/tty/serial/qcom_geni_serial.c
@@ -1663,17 +1663,15 @@ static int geni_serial_resource_init(struct qcom_geni_serial_port *port)
 static void qcom_geni_serial_pm(struct uart_port *uport,
 		unsigned int new_state, unsigned int old_state)
 {
-	struct qcom_geni_serial_port *port = to_dev_port(uport);
-
 	/* If we've never been called, treat it as off */
 	if (old_state == UART_PM_STATE_UNDEFINED)
 		old_state = UART_PM_STATE_OFF;
 
 	if (new_state == UART_PM_STATE_ON && old_state == UART_PM_STATE_OFF)
-		geni_serial_resources_on(uport);
+		pm_runtime_resume_and_get(uport->dev);
 	else if (new_state == UART_PM_STATE_OFF &&
 			old_state == UART_PM_STATE_ON)
-		geni_serial_resources_off(uport);
+		pm_runtime_put_sync(uport->dev);
 
 }
 
@@ -1811,9 +1809,11 @@ static int qcom_geni_serial_probe(struct platform_device *pdev)
 		return ret;
 	}
 
+	pm_runtime_enable(port->se.dev);
+
 	ret = uart_add_one_port(drv, uport);
 	if (ret)
-		return ret;
+		goto error;
 
 	if (port->wakeup_irq > 0) {
 		device_init_wakeup(&pdev->dev, true);
@@ -1822,11 +1822,15 @@ static int qcom_geni_serial_probe(struct platform_device *pdev)
 		if (ret) {
 			device_init_wakeup(&pdev->dev, false);
 			uart_remove_one_port(drv, uport);
-			return ret;
+			goto error;
 		}
 	}
 
 	return 0;
+
+error:
+	pm_runtime_disable(port->se.dev);
+	return ret;
 }
 
 static void qcom_geni_serial_remove(struct platform_device *pdev)
@@ -1836,9 +1840,26 @@ static void qcom_geni_serial_remove(struct platform_device *pdev)
 
 	dev_pm_clear_wake_irq(&pdev->dev);
 	device_init_wakeup(&pdev->dev, false);
+	pm_runtime_disable(port->se.dev);
 	uart_remove_one_port(drv, &port->uport);
 }
 
+static int qcom_geni_serial_runtime_suspend(struct device *dev)
+{
+	struct qcom_geni_serial_port *port = dev_get_drvdata(dev);
+	struct uart_port *uport = &port->uport;
+
+	return geni_serial_resources_off(uport);
+};
+
+static int qcom_geni_serial_runtime_resume(struct device *dev)
+{
+	struct qcom_geni_serial_port *port = dev_get_drvdata(dev);
+	struct uart_port *uport = &port->uport;
+
+	return geni_serial_resources_on(uport);
+};
+
 static int qcom_geni_serial_suspend(struct device *dev)
 {
 	struct qcom_geni_serial_port *port = dev_get_drvdata(dev);
@@ -1882,6 +1903,8 @@ static const struct qcom_geni_device_data qcom_geni_uart_data = {
 };
 
 static const struct dev_pm_ops qcom_geni_serial_pm_ops = {
+	SET_RUNTIME_PM_OPS(qcom_geni_serial_runtime_suspend,
+			   qcom_geni_serial_runtime_resume, NULL)
 	SYSTEM_SLEEP_PM_OPS(qcom_geni_serial_suspend, qcom_geni_serial_resume)
 };
 
-- 
2.17.1