diff options
Diffstat (limited to 'drivers/serial/Kconfig')
| -rw-r--r-- | drivers/serial/Kconfig | 65 |
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" |