xref: /openbmc/u-boot/drivers/serial/Kconfig (revision e2c1c5ba)
1config REQUIRE_SERIAL_CONSOLE
2	bool "Require a serial port for console"
3	# Running without a serial console is not supported by the
4	# non-dm serial code
5	depends on DM_SERIAL
6	default y
7	help
8	  Require a serial port for the console, and panic if none is found
9	  during serial port initialization (default y). Set this to n on
10	  boards which have no debug serial port whatsoever.
11
12config DM_SERIAL
13	bool "Enable Driver Model for serial drivers"
14	depends on DM
15	help
16	  Enable driver model for serial. This replaces
17	  drivers/serial/serial.c with the serial uclass, which
18	  implements serial_putc() etc. The uclass interface is
19	  defined in include/serial.h.
20
21config DEBUG_UART
22	bool "Enable an early debug UART for debugging"
23	help
24	  The debug UART is intended for use very early in U-Boot to debug
25	  problems when an ICE or other debug mechanism is not available.
26
27	  To use it you should:
28	  - Make sure your UART supports this interface
29	  - Enable CONFIG_DEBUG_UART
30	  - Enable the CONFIG for your UART to tell it to provide this interface
31	        (e.g. CONFIG_DEBUG_UART_NS16550)
32	  - Define the required settings as needed (see below)
33	  - Call debug_uart_init() before use
34	  - Call debug_uart_putc() to output a character
35
36	  Depending on your platform it may be possible to use this UART before
37	  a stack is available.
38
39	  If your UART does not support this interface you can probably add
40	  support quite easily. Remember that you cannot use driver model and
41	  it is preferred to use no stack.
42
43	  You must not use this UART once driver model is working and the
44	  serial drivers are up and running (done in serial_init()). Otherwise
45	  the drivers may conflict and you will get strange output.
46
47choice
48	prompt "Select which UART will provide the debug UART"
49	depends on DEBUG_UART
50
51config DEBUG_UART_NS16550
52	bool "ns16550"
53	help
54	  Select this to enable a debug UART using the ns16550 driver. You
55	  will need to provide parameters to make this work. The driver will
56	  be available until the real driver model serial is running.
57
58config DEBUG_EFI_CONSOLE
59	bool "EFI"
60	depends on EFI_APP
61	help
62	  Select this to enable a debug console which calls back to EFI to
63	  output to the console. This can be useful for early debugging of
64	  U-Boot when running on top of EFI (Extensive Firmware Interface).
65	  This is a type of BIOS used by PCs.
66
67config DEBUG_UART_S5P
68	bool "Samsung S5P"
69	help
70	  Select this to enable a debug UART using the serial_s5p driver. You
71	  will need to provide parameters to make this work. The driver will
72	  be available until the real driver-model serial is running.
73
74endchoice
75
76config DEBUG_UART_BASE
77	hex "Base address of UART"
78	depends on DEBUG_UART
79	help
80	  This is the base address of your UART for memory-mapped UARTs.
81
82	  A default should be provided by your board, but if not you will need
83	  to use the correct value here.
84
85config DEBUG_UART_CLOCK
86	int "UART input clock"
87	depends on DEBUG_UART
88	help
89	  The UART input clock determines the speed of the internal UART
90	  circuitry. The baud rate is derived from this by dividing the input
91	  clock down.
92
93	  A default should be provided by your board, but if not you will need
94	  to use the correct value here.
95
96config DEBUG_UART_SHIFT
97	int "UART register shift"
98	depends on DEBUG_UART
99	default 0 if DEBUG_UART
100	help
101	  Some UARTs (notably ns16550) support different register layouts
102	  where the registers are spaced either as bytes, words or some other
103	  value. Use this value to specify the shift to use, where 0=byte
104	  registers, 2=32-bit word registers, etc.
105
106config SANDBOX_SERIAL
107	bool "Sandbox UART support"
108	depends on SANDBOX && DM
109	help
110	  Select this to enable a seral UART for sandbox. This is required to
111	  operate correctly, otherwise you will see no serial output from
112	  sandbox. The emulated UART will display to the console and console
113	  input will be fed into the UART. This allows you to interact with
114	  U-Boot.
115
116	  The operation of the console is controlled by the -t command-line
117	  flag. In raw mode, U-Boot sees all characters from the terminal
118	  before they are processed, including Ctrl-C. In cooked mode, Ctrl-C
119	  is processed by the terminal, and terminates U-Boot. Valid options
120	  are:
121
122	     -t raw-with-sigs	Raw mode, Ctrl-C will terminate U-Boot
123	     -t raw		Raw mode, Ctrl-C is processed by U-Boot
124	     -t cooked		Cooked mode, Ctrl-C terminates
125
126config UNIPHIER_SERIAL
127	bool "Support for UniPhier on-chip UART"
128	depends on ARCH_UNIPHIER && DM_SERIAL
129	help
130	  If you have a UniPhier based board and want to use the on-chip
131	  serial ports, say Y to this option. If unsure, say N.
132
133config X86_SERIAL
134	bool "Support for 16550 serial port on x86 machines"
135	depends on X86
136	default y
137	help
138	  Most x86 machines have a ns16550 UART or compatible. This can be
139	  enabled in the device tree with the correct input clock frequency
140	  provided (default 1843200). Enable this to obtain serial console
141	  output.
142