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/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2019 Antony Pavlov <antonynpavlov@gmail.com>
*
* This file is part of barebox.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#ifndef __ASM_DEBUG_LL_LITEX__
#define __ASM_DEBUG_LL_LITEX__
/** @file
* This File contains declaration for early output support
*/
#include <linux/kconfig.h>
#define DEBUG_LL_UART_ADDR 0xf0001000
#define UART_RXTX 0x00
#define UART_TXFULL 0x04
#define UART_RXEMPTY 0x08
#define UART_EV_PENDING 0x10
#define UART_EV_RX (1 << 1)
#ifndef __ASSEMBLY__
/*
* C macros
*/
#include <asm/io.h>
static inline void PUTC_LL(char ch)
{
#ifdef CONFIG_DEBUG_LL
/* wait for space */
while (__raw_readb((u8 *)DEBUG_LL_UART_ADDR + UART_TXFULL))
;
__raw_writeb(ch, (u8 *)DEBUG_LL_UART_ADDR + UART_RXTX);
#endif /* CONFIG_DEBUG_LL */
}
#else /* __ASSEMBLY__ */
/*
* Macros for use in assembly language code
*/
/*
* output a character in a0
*/
.macro debug_ll_outc_a0
#ifdef CONFIG_DEBUG_LL
li t0, DEBUG_LL_UART_ADDR
201:
lbu t1, UART_TXFULL(t0) /* uart tx full ? */
andi t1, t1, 0xff
bnez t1, 201b /* try again */
sb a0, UART_RXTX(t0) /* write the character */
#endif /* CONFIG_DEBUG_LL */
.endm
/*
* output a character
*/
.macro debug_ll_outc chr
#ifdef CONFIG_DEBUG_LL
li a0, \chr
debug_ll_outc_a0
#endif /* CONFIG_DEBUG_LL */
.endm
/*
* check character in input buffer
* return value:
* v0 = 0 no character in input buffer
* v0 != 0 character in input buffer
*/
.macro debug_ll_tstc
#ifdef CONFIG_DEBUG_LL
li t0, DEBUG_LL_UART_ADDR
/* get line status and check for data present */
lbu s1, UART_RXEMPTY(t0)
bnez s1, 243f
li s1, 1
j 244f
243: li s1, 0
244: nop
#endif /* CONFIG_DEBUG_LL */
.endm
/*
* get character to v0
*/
.macro debug_ll_getc
#ifdef CONFIG_DEBUG_LL
204:
debug_ll_tstc
/* try again */
beqz s1, 204b
/* read a character */
lb s1, UART_RXTX(t0)
li t1, UART_EV_RX
sb t1, UART_EV_PENDING(t0)
#endif /* CONFIG_DEBUG_LL */
.endm
#endif /* __ASSEMBLY__ */
#endif /* __ASM_DEBUG_LL_LITEX__ */
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