Git Repo - J-u-boot.git/blame_incremental

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Commit	Line	Data
	1	/*
	2	* Early debug UART support
	3	*
	4	* (C) Copyright 2014 Google, Inc
	5	* Writte by Simon Glass <[email protected]>
	6	*
	7	* SPDX-License-Identifier: GPL-2.0+
	8	*/
	9
	10	#ifndef _DEBUG_UART_H
	11	#define _DEBUG_UART_H
	12
	13	/*
	14	* The debug UART is intended for use very early in U-Boot to debug problems
	15	* when an ICE or other debug mechanism is not available.
	16	*
	17	* To use it you should:
	18	* - Make sure your UART supports this interface
	19	* - Enable CONFIG_DEBUG_UART
	20	* - Enable the CONFIG for your UART to tell it to provide this interface
	21	* (e.g. CONFIG_DEBUG_UART_NS16550)
	22	* - Define the required settings as needed (see below)
	23	* - Call debug_uart_init() before use
	24	* - Call printch() to output a character
	25	*
	26	* Depending on your platform it may be possible to use this UART before a
	27	* stack is available.
	28	*
	29	* If your UART does not support this interface you can probably add support
	30	* quite easily. Remember that you cannot use driver model and it is preferred
	31	* to use no stack.
	32	*
	33	* You must not use this UART once driver model is working and the serial
	34	* drivers are up and running (done in serial_init()). Otherwise the drivers
	35	* may conflict and you will get strange output.
	36	*
	37	*
	38	* To enable the debug UART in your serial driver:
	39	*
	40	* - #include <debug_uart.h>
	41	* - Define _debug_uart_init(), trying to avoid using the stack
	42	* - Define _debug_uart_putc() as static inline (avoiding stack usage)
	43	* - Immediately afterwards, add DEBUG_UART_FUNCS to define the rest of the
	44	* functionality (printch(), etc.)
	45	*
	46	* If your board needs additional init for the UART to work, enable
	47	* CONFIG_DEBUG_UART_BOARD_INIT and write a function called
	48	* board_debug_uart_init() to perform that init. When debug_uart_init() is
	49	* called, the init will happen automatically.
	50	*/
	51
	52	/**
	53	* debug_uart_init() - Set up the debug UART ready for use
	54	*
	55	* This sets up the UART with the correct baud rate, etc.
	56	*
	57	* Available CONFIG is:
	58	*
	59	* - CONFIG_DEBUG_UART_BASE: Base address of UART
	60	* - CONFIG_BAUDRATE: Requested baud rate
	61	* - CONFIG_DEBUG_UART_CLOCK: Input clock for UART
	62	*/
	63	void debug_uart_init(void);
	64
	65	#ifdef CONFIG_DEBUG_UART_BOARD_INIT
	66	void board_debug_uart_init(void);
	67	#else
	68	static inline void board_debug_uart_init(void)
	69	{
	70	}
	71	#endif
	72
	73	/**
	74	* printch() - Output a character to the debug UART
	75	*
	76	* @ch: Character to output
	77	*/
	78	void printch(int ch);
	79
	80	/**
	81	* printascii() - Output an ASCII string to the debug UART
	82	*
	83	* @str: String to output
	84	*/
	85	void printascii(const char *str);
	86
	87	/**
	88	* printhex2() - Output a 2-digit hex value
	89	*
	90	* @value: Value to output
	91	*/
	92	void printhex2(uint value);
	93
	94	/**
	95	* printhex4() - Output a 4-digit hex value
	96	*
	97	* @value: Value to output
	98	*/
	99	void printhex4(uint value);
	100
	101	/**
	102	* printhex8() - Output a 8-digit hex value
	103	*
	104	* @value: Value to output
	105	*/
	106	void printhex8(uint value);
	107
	108	#ifdef CONFIG_DEBUG_UART_ANNOUNCE
	109	#define _DEBUG_UART_ANNOUNCE printascii("<debug_uart> ");
	110	#else
	111	#define _DEBUG_UART_ANNOUNCE
	112	#endif
	113
	114	#define serial_dout(reg, value) \
	115	serial_out_shift((char *)com_port + \
	116	((char )reg - (char )com_port) * \
	117	(1 << CONFIG_DEBUG_UART_SHIFT), \
	118	CONFIG_DEBUG_UART_SHIFT, value)
	119	#define serial_din(reg) \
	120	serial_in_shift((char *)com_port + \
	121	((char )reg - (char )com_port) * \
	122	(1 << CONFIG_DEBUG_UART_SHIFT), \
	123	CONFIG_DEBUG_UART_SHIFT)
	124
	125	/*
	126	* Now define some functions - this should be inserted into the serial driver
	127	*/
	128	#define DEBUG_UART_FUNCS \
	129	\
	130	static inline void _printch(int ch) \
	131	{ \
	132	if (ch == '\n') \
	133	_debug_uart_putc('\r'); \
	134	_debug_uart_putc(ch); \
	135	} \
	136	\
	137	void printch(int ch) \
	138	{ \
	139	_printch(ch); \
	140	} \
	141	\
	142	void printascii(const char *str) \
	143	{ \
	144	while (*str) \
	145	_printch(*str++); \
	146	} \
	147	\
	148	static inline void printhex1(uint digit) \
	149	{ \
	150	digit &= 0xf; \
	151	_debug_uart_putc(digit > 9 ? digit - 10 + 'a' : digit + '0'); \
	152	} \
	153	\
	154	static inline void printhex(uint value, int digits) \
	155	{ \
	156	while (digits-- > 0) \
	157	printhex1(value >> (4 * digits)); \
	158	} \
	159	\
	160	void printhex2(uint value) \
	161	{ \
	162	printhex(value, 2); \
	163	} \
	164	\
	165	void printhex4(uint value) \
	166	{ \
	167	printhex(value, 4); \
	168	} \
	169	\
	170	void printhex8(uint value) \
	171	{ \
	172	printhex(value, 8); \
	173	} \
	174	\
	175	void debug_uart_init(void) \
	176	{ \
	177	board_debug_uart_init(); \
	178	_debug_uart_init(); \
	179	_DEBUG_UART_ANNOUNCE \
	180	} \
	181
	182	#endif