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-rw-r--r--drivers/serial/Kconfig65
1 files changed, 63 insertions, 2 deletions
diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
index a0b6e02..1686a1f 100644
--- a/drivers/serial/Kconfig
+++ b/drivers/serial/Kconfig
@@ -2,8 +2,69 @@ config DM_SERIAL
bool "Enable Driver Model for serial drivers"
depends on DM
help
- If you want to use driver model for serial drivers, say Y.
- To use legacy serial drivers, say N.
+ Enable driver model for serial. This replaces
+ drivers/serial/serial.c with the serial uclass, which
+ implements serial_putc() etc. The uclass interface is
+ defined in include/serial.h.
+
+config DEBUG_UART
+ bool "Enable an early debug UART for debugging"
+ help
+ The debug UART is intended for use very early in U-Boot to debug
+ problems when an ICE or other debug mechanism is not available.
+
+ To use it you should:
+ - Make sure your UART supports this interface
+ - Enable CONFIG_DEBUG_UART
+ - Enable the CONFIG for your UART to tell it to provide this interface
+ (e.g. CONFIG_DEBUG_UART_NS16550)
+ - Define the required settings as needed (see below)
+ - Call debug_uart_init() before use
+ - Call debug_uart_putc() to output a character
+
+ Depending on your platform it may be possible to use this UART before
+ a stack is available.
+
+ If your UART does not support this interface you can probably add
+ support quite easily. Remember that you cannot use driver model and
+ it is preferred to use no stack.
+
+ You must not use this UART once driver model is working and the
+ serial drivers are up and running (done in serial_init()). Otherwise
+ the drivers may conflict and you will get strange output.
+
+choice
+ prompt "Select which UART will provide the debug UART"
+ depends on DEBUG_UART
+
+config DEBUG_UART_NS16550
+ bool "ns16550"
+ help
+ Select this to enable a debug UART using the ns16550 driver. You
+ will need to provide parameters to make this work. The driver will
+ be available until the real driver model serial is running.
+
+endchoice
+
+config DEBUG_UART_BASE
+ hex "Base address of UART"
+ depends on DEBUG_UART
+ help
+ This is the base address of your UART for memory-mapped UARTs.
+
+ A default should be provided by your board, but if not you will need
+ to use the correct value here.
+
+config DEBUG_UART_CLOCK
+ int "UART input clock"
+ depends on DEBUG_UART
+ help
+ The UART input clock determines the speed of the internal UART
+ circuitry. The baud rate is derived from this by dividing the input
+ clock down.
+
+ A default should be provided by your board, but if not you will need
+ to use the correct value here.
config UNIPHIER_SERIAL
bool "UniPhier on-chip UART support"