serial: of-serial: fix up PM ops on no_console_suspend and port type

This patch fixes commit 2dea53bf57783f243c892e99c10c6921e956aa7e,
"serial: of-serial: add PM suspend/resume support", which disables
the uart clock on suspend, but also causes a hardware hang on register
access if no_console_suspend command line option is used.

Also, not every of_serial device is an 8250 port, so the serial8250
suspend/resume functions should only be applied to a real 8250 port.

Signed-off-by: Jingchang Lu <jingchang.lu@freescale.com>
Tested-by: Joseph Lo <josephl@nvidia.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/of_serial.c b/drivers/tty/serial/of_serial.c
index 8bc2563..9c64ad2 100644 (file)
--- a/drivers/tty/serial/of_serial.c
+++ b/drivers/tty/serial/of_serial.c
@@ -9,6 +9,7 @@
  *  2 of the License, or (at your option) any later version.
  *
  */
+#include <linux/console.h>
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/delay.h>
@@ -241,13 +242,48 @@ static int of_platform_serial_remove(struct platform_device *ofdev)
 }
 
 #ifdef CONFIG_PM_SLEEP
-static int of_serial_suspend(struct device *dev)
+#ifdef CONFIG_SERIAL_8250
+static void of_serial_suspend_8250(struct of_serial_info *info)
 {
-       struct of_serial_info *info = dev_get_drvdata(dev);
+       struct uart_8250_port *port8250 = serial8250_get_port(info->line);
+       struct uart_port *port = &port8250->port;
 
        serial8250_suspend_port(info->line);
-       if (info->clk)
+       if (info->clk && (!uart_console(port) || console_suspend_enabled))
                clk_disable_unprepare(info->clk);
+}
+
+static void of_serial_resume_8250(struct of_serial_info *info)
+{
+       struct uart_8250_port *port8250 = serial8250_get_port(info->line);
+       struct uart_port *port = &port8250->port;
+
+       if (info->clk && (!uart_console(port) || console_suspend_enabled))
+               clk_prepare_enable(info->clk);
+
+       serial8250_resume_port(info->line);
+}
+#else
+static inline void of_serial_suspend_8250(struct of_serial_info *info)
+{
+}
+
+static inline void of_serial_resume_8250(struct of_serial_info *info)
+{
+}
+#endif
+
+static int of_serial_suspend(struct device *dev)
+{
+       struct of_serial_info *info = dev_get_drvdata(dev);
+
+       switch(info->type) {
+       case PORT_8250 ... PORT_MAX_8250:
+               of_serial_suspend_8250(info);
+               break;
+       default:
+               break;
+       }
 
        return 0;
 }
@@ -256,10 +292,13 @@ static int of_serial_resume(struct device *dev)
 {
        struct of_serial_info *info = dev_get_drvdata(dev);
 
-       if (info->clk)
-               clk_prepare_enable(info->clk);
-
-       serial8250_resume_port(info->line);
+       switch(info->type) {
+       case PORT_8250 ... PORT_MAX_8250:
+               of_serial_resume_8250(info);
+               break;
+       default:
+               break;
+       }
 
        return 0;
 }