[PATCH 04/10] serial: stm32: add pm_runtime support

From: Erwan Le Ray
Date: Tue Jun 04 2019 - 05:00:01 EST


Use pm_runtime for clock management.

Signed-off-by: Bich Hemon <bich.hemon@xxxxxx>
Signed-off-by: Erwan Le Ray <erwan.leray@xxxxxx>

diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index 8a7c582..05d2ef6 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -765,13 +765,13 @@ static void stm32_pm(struct uart_port *port, unsigned int state,

switch (state) {
case UART_PM_STATE_ON:
- clk_prepare_enable(stm32port->clk);
+ pm_runtime_get_sync(port->dev);
break;
case UART_PM_STATE_OFF:
spin_lock_irqsave(&port->lock, flags);
stm32_clr_bits(port, ofs->cr1, BIT(cfg->uart_enable_bit));
spin_unlock_irqrestore(&port->lock, flags);
- clk_disable_unprepare(stm32port->clk);
+ pm_runtime_put_sync(port->dev);
break;
}
}
@@ -1040,6 +1040,11 @@ static int stm32_serial_probe(struct platform_device *pdev)

platform_set_drvdata(pdev, &stm32port->port);

+ pm_runtime_get_noresume(&pdev->dev);
+ pm_runtime_set_active(&pdev->dev);
+ pm_runtime_enable(&pdev->dev);
+ pm_runtime_put_sync(&pdev->dev);
+
return 0;

err_nowup:
@@ -1058,6 +1063,9 @@ static int stm32_serial_remove(struct platform_device *pdev)
struct stm32_port *stm32_port = to_stm32_port(port);
struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
struct stm32_usart_config *cfg = &stm32_port->info->cfg;
+ int err;
+
+ pm_runtime_get_sync(&pdev->dev);

stm32_clr_bits(port, ofs->cr3, USART_CR3_DMAR);

@@ -1084,7 +1092,12 @@ static int stm32_serial_remove(struct platform_device *pdev)

clk_disable_unprepare(stm32_port->clk);

- return uart_remove_one_port(&stm32_usart_driver, port);
+ err = uart_remove_one_port(&stm32_usart_driver, port);
+
+ pm_runtime_disable(&pdev->dev);
+ pm_runtime_put_noidle(&pdev->dev);
+
+ return err;
}


@@ -1241,7 +1254,29 @@ static int stm32_serial_resume(struct device *dev)
}
#endif /* CONFIG_PM_SLEEP */

+static int __maybe_unused stm32_serial_runtime_suspend(struct device *dev)
+{
+ struct uart_port *port = dev_get_drvdata(dev);
+ struct stm32_port *stm32port = container_of(port,
+ struct stm32_port, port);
+
+ clk_disable_unprepare(stm32port->clk);
+
+ return 0;
+}
+
+static int __maybe_unused stm32_serial_runtime_resume(struct device *dev)
+{
+ struct uart_port *port = dev_get_drvdata(dev);
+ struct stm32_port *stm32port = container_of(port,
+ struct stm32_port, port);
+
+ return clk_prepare_enable(stm32port->clk);
+}
+
static const struct dev_pm_ops stm32_serial_pm_ops = {
+ SET_RUNTIME_PM_OPS(stm32_serial_runtime_suspend,
+ stm32_serial_runtime_resume, NULL)
SET_SYSTEM_SLEEP_PM_OPS(stm32_serial_suspend, stm32_serial_resume)
};

--
1.9.1