[PATCH v3 04/10] serial: stm32: add pm_runtime support

[Erwan Le Ray]

Use pm_runtime for clock management.

Signed-off-by: Bich Hemon <bich.he...@st.com>
Signed-off-by: Erwan Le Ray <erwan.le...@st.com>

diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index a8f20ba..41898c4 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -810,13 +810,13 @@ 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;
        }
 }
@@ -1111,6 +1111,11 @@ 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_wirq:
@@ -1132,6 +1137,9 @@ static int stm32_serial_remove(struct platform_device 
*pdev)
        struct uart_port *port = platform_get_drvdata(pdev);
        struct stm32_port *stm32_port = to_stm32_port(port);
        struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
+       int err;
+
+       pm_runtime_get_sync(&pdev->dev);
 
        stm32_clr_bits(port, ofs->cr3, USART_CR3_DMAR);
 
@@ -1160,7 +1168,12 @@ 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;
 }
 
 
@@ -1317,7 +1330,29 @@ 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