If we have stdout-path specified for earlycon, we must prevent
the debug console from idling until runtime PM kicks in.

Signed-off-by: Tony Lindgren <t...@atomide.com>
---
 drivers/bus/ti-sysc.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/drivers/bus/ti-sysc.c b/drivers/bus/ti-sysc.c
--- a/drivers/bus/ti-sysc.c
+++ b/drivers/bus/ti-sysc.c
@@ -206,6 +206,50 @@ static int sysc_parse_and_check_child_range(struct sysc 
*ddata)
        return 0;
 }
 
+static struct device_node *stdout_path;
+
+static void sysc_init_stdout_path(struct sysc *ddata)
+{
+       struct device_node *np = NULL;
+       const char *uart;
+
+       if (IS_ERR(stdout_path))
+               return;
+
+       if (stdout_path)
+               return;
+
+       np = of_find_node_by_path("/chosen");
+       if (!np)
+               goto err;
+
+       uart = of_get_property(np, "stdout-path", NULL);
+       if (!uart)
+               goto err;
+
+       np = of_find_node_by_path(uart);
+       if (!np)
+               goto err;
+
+       stdout_path = np;
+
+       return;
+
+err:
+       stdout_path = ERR_PTR(-ENODEV);
+}
+
+static void sysc_check_quirk_stdout(struct sysc *ddata,
+                                   struct device_node *np)
+{
+       sysc_init_stdout_path(ddata);
+       if (np != stdout_path)
+               return;
+
+       ddata->cfg.quirks |= SYSC_QUIRK_NO_IDLE_ON_INIT |
+                               SYSC_QUIRK_NO_RESET_ON_INIT;
+}
+
 /**
  * sysc_check_one_child - check child configuration
  * @ddata: device driver data
@@ -224,6 +268,8 @@ static int sysc_check_one_child(struct sysc *ddata,
        if (name)
                dev_warn(ddata->dev, "really a child ti,hwmods property?");
 
+       sysc_check_quirk_stdout(ddata, np);
+
        return 0;
 }
 
-- 
2.16.2

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