| config DM_SERIAL |
| bool "Enable Driver Model for serial drivers" |
| depends on DM |
| help |
| 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 DEBUG_UART_SHIFT |
| int "UART register shift" |
| depends on DEBUG_UART |
| default 0 if DEBUG_UART |
| help |
| Some UARTs (notably ns16550) support different register layouts |
| where the registers are spaced either as bytes, words or some other |
| value. Use this value to specify the shift to use, where 0=byte |
| registers, 2=32-bit word registers, etc. |
| |
| config UNIPHIER_SERIAL |
| bool "Support for UniPhier on-chip UART" |
| depends on ARCH_UNIPHIER && DM_SERIAL |
| help |
| If you have a UniPhier based board and want to use the on-chip |
| serial ports, say Y to this option. If unsure, say N. |