1config DM_SERIAL 2 bool "Enable Driver Model for serial drivers" 3 depends on DM 4 help 5 Enable driver model for serial. This replaces 6 drivers/serial/serial.c with the serial uclass, which 7 implements serial_putc() etc. The uclass interface is 8 defined in include/serial.h. 9 10config DEBUG_UART 11 bool "Enable an early debug UART for debugging" 12 help 13 The debug UART is intended for use very early in U-Boot to debug 14 problems when an ICE or other debug mechanism is not available. 15 16 To use it you should: 17 - Make sure your UART supports this interface 18 - Enable CONFIG_DEBUG_UART 19 - Enable the CONFIG for your UART to tell it to provide this interface 20 (e.g. CONFIG_DEBUG_UART_NS16550) 21 - Define the required settings as needed (see below) 22 - Call debug_uart_init() before use 23 - Call debug_uart_putc() to output a character 24 25 Depending on your platform it may be possible to use this UART before 26 a stack is available. 27 28 If your UART does not support this interface you can probably add 29 support quite easily. Remember that you cannot use driver model and 30 it is preferred to use no stack. 31 32 You must not use this UART once driver model is working and the 33 serial drivers are up and running (done in serial_init()). Otherwise 34 the drivers may conflict and you will get strange output. 35 36config DEBUG_UART_BASE 37 hex "Base address of UART" 38 depends on DEBUG_UART 39 help 40 This is the base address of your UART for memory-mapped UARTs. 41 42 A default should be provided by your board, but if not you will need 43 to use the correct value here. 44 45config DEBUG_UART_CLOCK 46 int "UART input clock" 47 depends on DEBUG_UART 48 help 49 The UART input clock determines the speed of the internal UART 50 circuitry. The baud rate is derived from this by dividing the input 51 clock down. 52 53 A default should be provided by your board, but if not you will need 54 to use the correct value here. 55 56config UNIPHIER_SERIAL 57 bool "UniPhier on-chip UART support" 58 depends on ARCH_UNIPHIER && DM_SERIAL 59 help 60 Support for the on-chip UARTs on the Panasonic UniPhier platform. 61