[PATCH v3 8/9] serial: qcom-geni: Enable PM runtime for serial driver

Praveen Talari
2025-05-02T03:11:54Z

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@quicinc.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