drivers/serial/Kconfig

   1 config 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
  10 config 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
  36 choice
  37         prompt "Select which UART will provide the debug UART"
  38         depends on DEBUG_UART
  39
  40 config DEBUG_UART_NS16550
  41         bool "ns16550"
  42         help
  43           Select this to enable a debug UART using the ns16550 driver. You
  44           will need to provide parameters to make this work. The driver will
  45           be available until the real driver model serial is running.
  46
  47 config DEBUG_EFI_CONSOLE
  48         bool "EFI"
  49         depends on EFI_APP
  50         help
  51           Select this to enable a debug console which calls back to EFI to
  52           output to the console. This can be useful for early debugging of
  53           U-Boot when running on top of EFI (Extensive Firmware Interface).
  54           This is a type of BIOS used by PCs.
  55
  56 config DEBUG_UART_S5P
  57         bool "Samsung S5P"
  58         help
  59           Select this to enable a debug UART using the serial_s5p driver. You
  60           will need to provide parameters to make this work. The driver will
  61           be available until the real driver-model serial is running.
  62
  63 endchoice
  64
  65 config DEBUG_UART_BASE
  66         hex "Base address of UART"
  67         depends on DEBUG_UART
  68         help
  69           This is the base address of your UART for memory-mapped UARTs.
  70
  71           A default should be provided by your board, but if not you will need
  72           to use the correct value here.
  73
  74 config DEBUG_UART_CLOCK
  75         int "UART input clock"
  76         depends on DEBUG_UART
  77         help
  78           The UART input clock determines the speed of the internal UART
  79           circuitry. The baud rate is derived from this by dividing the input
  80           clock down.
  81
  82           A default should be provided by your board, but if not you will need
  83           to use the correct value here.
  84
  85 config DEBUG_UART_SHIFT
  86         int "UART register shift"
  87         depends on DEBUG_UART
  88         default 0 if DEBUG_UART
  89         help
  90           Some UARTs (notably ns16550) support different register layouts
  91           where the registers are spaced either as bytes, words or some other
  92           value. Use this value to specify the shift to use, where 0=byte
  93           registers, 2=32-bit word registers, etc.
  94
  95 config SANDBOX_SERIAL
  96         bool "Sandbox UART support"
  97         depends on SANDBOX && DM
  98         help
  99           Select this to enable a seral UART for sandbox. This is required to
 100           operate correctly, otherwise you will see no serial output from
 101           sandbox. The emulated UART will display to the console and console
 102           input will be fed into the UART. This allows you to interact with
 103           U-Boot.
 104
 105           The operation of the console is controlled by the -t command-line
 106           flag. In raw mode, U-Boot sees all characters from the terminal
 107           before they are processed, including Ctrl-C. In cooked mode, Ctrl-C
 108           is processed by the terminal, and terminates U-Boot. Valid options
 109           are:
 110
 111              -t raw-with-sigs   Raw mode, Ctrl-C will terminate U-Boot
 112              -t raw             Raw mode, Ctrl-C is processed by U-Boot
 113              -t cooked          Cooked mode, Ctrl-C terminates
 114
 115 config UNIPHIER_SERIAL
 116         bool "Support for UniPhier on-chip UART"
 117         depends on ARCH_UNIPHIER && DM_SERIAL
 118         help
 119           If you have a UniPhier based board and want to use the on-chip
 120           serial ports, say Y to this option. If unsure, say N.
 121
 122 config X86_SERIAL
 123         bool "Support for 16550 serial port on x86 machines"
 124         depends on X86
 125         default y
 126         help
 127           Most x86 machines have a ns16550 UART or compatible. This can be
 128           enabled in the device tree with the correct input clock frequency
 129           provided (default 1843200). Enable this to obtain serial console
 130           output.