serial-uartlite: Add runtime support

Add runtime support

Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/uartlite.c b/drivers/tty/serial/uartlite.c
index 64c7248fe5fcdffaae2f5fdcca3fb4dab7469365..58296ebb9f7eb3e0aeb6081f7ddb24f9196ee4db 100644 (file)
--- a/drivers/tty/serial/uartlite.c
+++ b/drivers/tty/serial/uartlite.c
@@ -22,6 +22,7 @@
 #include <linux/of_device.h>
 #include <linux/of_platform.h>
 #include <linux/clk.h>
+#include <linux/pm_runtime.h>
 
 #define ULITE_NAME             "ttyUL"
 #define ULITE_MAJOR            204
@@ -54,6 +55,7 @@
 #define ULITE_CONTROL_RST_TX   0x01
 #define ULITE_CONTROL_RST_RX   0x02
 #define ULITE_CONTROL_IE       0x10
+#define UART_AUTOSUSPEND_TIMEOUT       3000
 
 /* Static pointer to console port */
 #ifdef CONFIG_SERIAL_UARTLITE_CONSOLE
@@ -391,12 +393,12 @@ static int ulite_verify_port(struct uart_port *port, struct serial_struct *ser)
 static void ulite_pm(struct uart_port *port, unsigned int state,
                     unsigned int oldstate)
 {
-       struct uartlite_data *pdata = port->private_data;
-
-       if (!state)
-               clk_enable(pdata->clk);
-       else
-               clk_disable(pdata->clk);
+       if (!state) {
+               pm_runtime_get_sync(port->dev);
+       } else {
+               pm_runtime_mark_last_busy(port->dev);
+               pm_runtime_put_autosuspend(port->dev);
+       }
 }
 
 #ifdef CONFIG_CONSOLE_POLL
@@ -738,11 +740,32 @@ static int __maybe_unused ulite_resume(struct device *dev)
        return 0;
 }
 
+static int __maybe_unused ulite_runtime_suspend(struct device *dev)
+{
+       struct uart_port *port = dev_get_drvdata(dev);
+       struct uartlite_data *pdata = port->private_data;
+
+       clk_disable(pdata->clk);
+       return 0;
+};
+
+static int __maybe_unused ulite_runtime_resume(struct device *dev)
+{
+       struct uart_port *port = dev_get_drvdata(dev);
+       struct uartlite_data *pdata = port->private_data;
+
+       clk_enable(pdata->clk);
+       return 0;
+}
 /* ---------------------------------------------------------------------
  * Platform bus binding
  */
 
-static SIMPLE_DEV_PM_OPS(ulite_pm_ops, ulite_suspend, ulite_resume);
+static const struct dev_pm_ops ulite_pm_ops = {
+       SET_SYSTEM_SLEEP_PM_OPS(ulite_suspend, ulite_resume)
+       SET_RUNTIME_PM_OPS(ulite_runtime_suspend,
+                          ulite_runtime_resume, NULL)
+};
 
 #if defined(CONFIG_OF)
 /* Match table for of_platform binding */
@@ -815,9 +838,15 @@ static int ulite_probe(struct platform_device *pdev)
                return ret;
        }
 
+       pm_runtime_use_autosuspend(&pdev->dev);
+       pm_runtime_set_autosuspend_delay(&pdev->dev, UART_AUTOSUSPEND_TIMEOUT);
+       pm_runtime_set_active(&pdev->dev);
+       pm_runtime_enable(&pdev->dev);
+
        ret = ulite_assign(&pdev->dev, id, res->start, irq, pdata);
 
-       clk_disable(pdata->clk);
+       pm_runtime_mark_last_busy(&pdev->dev);
+       pm_runtime_put_autosuspend(&pdev->dev);
 
        return ret;
 }
@@ -826,9 +855,14 @@ static int ulite_remove(struct platform_device *pdev)
 {
        struct uart_port *port = dev_get_drvdata(&pdev->dev);
        struct uartlite_data *pdata = port->private_data;
+       int rc;
 
        clk_disable_unprepare(pdata->clk);
-       return ulite_release(&pdev->dev);
+       rc = ulite_release(&pdev->dev);
+       pm_runtime_disable(&pdev->dev);
+       pm_runtime_set_suspended(&pdev->dev);
+       pm_runtime_dont_use_autosuspend(&pdev->dev);
+       return rc;
 }
 
 /* work with hotplug and coldplug */