linux-kernel - [PATCH v2 8/9] serial: qcom-geni: Enable PM runtime for serial driver

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Message-ID: <20250418151235.27787-9-quic_ptalari@quicinc.com>
Date: Fri, 18 Apr 2025 20:42:34 +0530
From: Praveen Talari <quic_ptalari@...cinc.com>
To: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Jiri Slaby
	<jirislaby@...nel.org>, Rob Herring <robh@...nel.org>,
        Krzysztof Kozlowski
	<krzk+dt@...nel.org>,
        Conor Dooley <conor+dt@...nel.org>,
        Bjorn Andersson
	<andersson@...nel.org>,
        Konrad Dybcio <konradybcio@...nel.org>,
        Viresh Kumar
	<vireshk@...nel.org>, Nishanth Menon <nm@...com>,
        Stephen Boyd
	<sboyd@...nel.org>,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        Praveen Talari
	<quic_ptalari@...cinc.com>,
        <linux-arm-msm@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        <linux-serial@...r.kernel.org>, <devicetree@...r.kernel.org>,
        <linux-pm@...r.kernel.org>
CC: <psodagud@...cinc.com>, <djaggi@...cinc.com>, <quic_msavaliy@...cinc.com>,
        <quic_vtanuku@...cinc.com>, <quic_arandive@...cinc.com>,
        <quic_mnaresh@...cinc.com>, <quic_shazhuss@...cinc.com>
Subject: [PATCH v2 8/9] serial: qcom-geni: Enable PM runtime for serial driver

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@...cinc.com>
---
 drivers/tty/serial/qcom_geni_serial.c | 33 +++++++++++++++++++++++----
 1 file changed, 29 insertions(+), 4 deletions(-)

diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c
index 60afee3884a6..9d698c354510 100644
--- a/drivers/tty/serial/qcom_geni_serial.c
+++ b/drivers/tty/serial/qcom_geni_serial.c
@@ -1686,10 +1686,10 @@ static void qcom_geni_serial_pm(struct uart_port *uport,
 		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);
 
 }
 
@@ -1827,9 +1827,11 @@ 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);
@@ -1839,11 +1841,15 @@ static int qcom_geni_serial_probe(struct platform_device *pdev)
 			device_init_wakeup(&pdev->dev, false);
 			ida_free(&port_ida, uport->line);
 			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)
@@ -1855,9 +1861,26 @@ static void qcom_geni_serial_remove(struct platform_device *pdev)
 	dev_pm_clear_wake_irq(&pdev->dev);
 	device_init_wakeup(&pdev->dev, false);
 	ida_free(&port_ida, uport->line);
+	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);
@@ -1901,6 +1924,8 @@ 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