fiq_debugger: Add option to apply uart overlay by FIQ_DEBUGGER_UART_OVERLAY

fiq_debugger is taking over uart, so it is necessary to disable
original uart in DT file. It can be done manually or by overlay.

Change-Id: I9f50ec15b0e22e602d73b9f745fc8666f8925d09
Signed-off-by: Dmitry Shmidt <dimitrysh@google.com>

diff --git a/drivers/staging/android/fiq_debugger/Kconfig b/drivers/staging/android/fiq_debugger/Kconfig
index 56f7f99..60fc224 100644 (file)
--- a/drivers/staging/android/fiq_debugger/Kconfig
+++ b/drivers/staging/android/fiq_debugger/Kconfig
@@ -42,6 +42,15 @@ config FIQ_DEBUGGER_CONSOLE_DEFAULT_ENABLE
          If enabled, this puts the fiq debugger into console mode by default.
          Otherwise, the fiq debugger will start out in debug mode.
 
+config FIQ_DEBUGGER_UART_OVERLAY
+       bool "Install uart DT overlay"
+       depends on FIQ_DEBUGGER
+       select OF_OVERLAY
+       default n
+       help
+         If enabled, fiq debugger is calling fiq_debugger_uart_overlay()
+         that will apply overlay uart_overlay@0 to disable proper uart.
+
 config FIQ_WATCHDOG
        bool
        select FIQ_DEBUGGER

diff --git a/drivers/staging/android/fiq_debugger/fiq_debugger.c b/drivers/staging/android/fiq_debugger/fiq_debugger.c
index 7f05683..0c55833 100644 (file)
--- a/drivers/staging/android/fiq_debugger/fiq_debugger.c
+++ b/drivers/staging/android/fiq_debugger/fiq_debugger.c
@@ -39,6 +39,10 @@
 #include <asm/fiq_glue.h>
 #endif
 
+#ifdef CONFIG_FIQ_DEBUGGER_UART_OVERLAY
+#include <linux/of.h>
+#endif
+
 #include <linux/uaccess.h>
 
 #include "fiq_debugger.h"
@@ -1201,11 +1205,37 @@ static struct platform_driver fiq_debugger_driver = {
        },
 };
 
+#if defined(CONFIG_FIQ_DEBUGGER_UART_OVERLAY)
+int fiq_debugger_uart_overlay(void)
+{
+       struct device_node *onp = of_find_node_by_path("/uart_overlay@0");
+       int ret;
+
+       if (!onp) {
+               pr_err("serial_debugger: uart overlay not found\n");
+               return -ENODEV;
+       }
+
+       ret = of_overlay_create(onp);
+       if (ret < 0) {
+               pr_err("serial_debugger: fail to create overlay: %d\n", ret);
+               of_node_put(onp);
+               return ret;
+       }
+
+       pr_info("serial_debugger: uart overlay applied\n");
+       return 0;
+}
+#endif
+
 static int __init fiq_debugger_init(void)
 {
 #if defined(CONFIG_FIQ_DEBUGGER_CONSOLE)
        fiq_debugger_tty_init();
 #endif
+#if defined(CONFIG_FIQ_DEBUGGER_UART_OVERLAY)
+       fiq_debugger_uart_overlay();
+#endif
        return platform_driver_register(&fiq_debugger_driver);
 }