xref: /openbmc/u-boot/drivers/serial/Kconfig (revision 29b103c7)
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
36choice
37	prompt "Select which UART will provide the debug UART"
38	depends on DEBUG_UART
39
40config 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
47endchoice
48
49config DEBUG_UART_BASE
50	hex "Base address of UART"
51	depends on DEBUG_UART
52	help
53	  This is the base address of your UART for memory-mapped UARTs.
54
55	  A default should be provided by your board, but if not you will need
56	  to use the correct value here.
57
58config DEBUG_UART_CLOCK
59	int "UART input clock"
60	depends on DEBUG_UART
61	help
62	  The UART input clock determines the speed of the internal UART
63	  circuitry. The baud rate is derived from this by dividing the input
64	  clock down.
65
66	  A default should be provided by your board, but if not you will need
67	  to use the correct value here.
68
69config DEBUG_UART_SHIFT
70	int "UART register shift"
71	depends on DEBUG_UART
72	default 0 if DEBUG_UART
73	help
74	  Some UARTs (notably ns16550) support different register layouts
75	  where the registers are spaced either as bytes, words or some other
76	  value. Use this value to specify the shift to use, where 0=byte
77	  registers, 2=32-bit word registers, etc.
78
79config SANDBOX_SERIAL
80	bool "Sandbox UART support"
81	depends on SANDBOX && DM
82	help
83	  Select this to enable a seral UART for sandbox. This is required to
84	  operate correctly, otherwise you will see no serial output from
85	  sandbox. The emulated UART will display to the console and console
86	  input will be fed into the UART. This allows you to interact with
87	  U-Boot.
88
89	  The operation of the console is controlled by the -t command-line
90	  flag. In raw mode, U-Boot sees all characters from the terminal
91	  before they are processed, including Ctrl-C. In cooked mode, Ctrl-C
92	  is processed by the terminal, and terminates U-Boot. Valid options
93	  are:
94
95	     -t raw-with-sigs	Raw mode, Ctrl-C will terminate U-Boot
96	     -t raw		Raw mode, Ctrl-C is processed by U-Boot
97	     -t cooked		Cooked mode, Ctrl-C terminates
98
99config UNIPHIER_SERIAL
100	bool "Support for UniPhier on-chip UART"
101	depends on ARCH_UNIPHIER && DM_SERIAL
102	help
103	  If you have a UniPhier based board and want to use the on-chip
104	  serial ports, say Y to this option. If unsure, say N.
105