The changes from commit 0dba45864b2a ("arm: Init the debug UART")
prevent the early debug UART from being initialized correctly.
By adding a new SoC specific early UART initialization function this
patch provides a generic location to add the required code. This code
has to be SoC and not board specific.
For the am33xx SoCs the fix consist of configuring early clocks.
Signed-off-by: Felix Brack <f...@ltec.ch>
---
arch/arm/mach-omap2/am33xx/board.c | 7 +++++++
drivers/serial/Kconfig | 13 +++++++++++++
include/debug_uart.h | 15 +++++++++++++++
3 files changed, 35 insertions(+)
diff --git a/arch/arm/mach-omap2/am33xx/board.c
b/arch/arm/mach-omap2/am33xx/board.c
index c44667668e..a7f0445b93 100644
--- a/arch/arm/mach-omap2/am33xx/board.c
+++ b/arch/arm/mach-omap2/am33xx/board.c
@@ -604,3 +604,10 @@ int arch_cpu_init_dm(void)
#endif
return 0;
}
+
+#if IS_ENABLED(CONFIG_DEBUG_UART_SOC_INIT)
+void soc_debug_uart_init(void)
+{
+ setup_early_clocks();
+}
+#endif
diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
index 345d1881f5..3da4064d35 100644
--- a/drivers/serial/Kconfig
+++ b/drivers/serial/Kconfig
@@ -490,6 +490,19 @@ config DEBUG_UART_SHIFT
value. Use this value to specify the shift to use, where 0=byte
registers, 2=32-bit word registers, etc.
+config DEBUG_UART_SOC_INIT
+ bool "Enable SoC-specific debug UART init"
+ depends on DEBUG_UART
+ help
+ Boards using the same SoC might require some common settings before
+ the debug UART can be used. The board specific board_debug_uart_init()
+ is not the right place for such common settings as they would apply
+ to a specific board only instead of all boards using the same SoC.
+ When this option is enabled, the SoC specific function
+ soc_debug_uart_init() will be called when debug_uart_init() is called.
+ You can put any code here that is needed to set up the UART ready for
+ use.
+
config DEBUG_UART_BOARD_INIT
bool "Enable board-specific debug UART init"
depends on DEBUG_UART
diff --git a/include/debug_uart.h b/include/debug_uart.h
index 714b369e6f..ebc84c44cd 100644
--- a/include/debug_uart.h
+++ b/include/debug_uart.h
@@ -42,6 +42,12 @@
* - Immediately afterwards, add DEBUG_UART_FUNCS to define the rest of the
* functionality (printch(), etc.)
*
+ * If your SoC needs additional init for the UART to work, enable
+ * CONFIG_DEBUG_UART_SOC_INIT and write a function called
+ * soc_debug_uart_init() to perform that init. When debug_uart_init() is
+ * called, the init will happen automatically. Board specific code does not
+ * go here, see board_debug_uart_init() below.
+ *
* If your board needs additional init for the UART to work, enable
* CONFIG_DEBUG_UART_BOARD_INIT and write a function called
* board_debug_uart_init() to perform that init. When debug_uart_init() is
@@ -61,6 +67,14 @@
*/
void debug_uart_init(void);
+#ifdef CONFIG_DEBUG_UART_SOC_INIT
+void soc_debug_uart_init(void);
+#else
+static inline void soc_debug_uart_init(void)
+{
+}
+#endif
+
#ifdef CONFIG_DEBUG_UART_BOARD_INIT
void board_debug_uart_init(void);
#else
@@ -192,6 +206,7 @@ void printdec(unsigned int value);
\
void debug_uart_init(void) \
{ \
+ soc_debug_uart_init(); \
board_debug_uart_init(); \
_debug_uart_init(); \
_DEBUG_UART_ANNOUNCE \
--
2.25.1
