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/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2012, 2013 Antony Pavlov <antonynpavlov@gmail.com>
*/
/** @file
* This file contains declaration for early output support
*/
#ifndef __INCLUDE_MIPS_ASM_DEBUG_LL_NS16550_H__
#define __INCLUDE_MIPS_ASM_DEBUG_LL_NS16550_H__
#ifdef CONFIG_DEBUG_LL
#ifndef DEBUG_LL_UART_ADDR
#error DEBUG_LL_UART_ADDR is undefined!
#endif
#ifndef DEBUG_LL_UART_SHIFT
#error DEBUG_LL_UART_SHIFT is undefined!
#endif
#ifndef DEBUG_LL_UART_DIVISOR
#error DEBUG_LL_UART_DIVISOR is undefined!
#endif
#endif /* CONFIG_DEBUG_LL */
#define UART_THR (0x0 << DEBUG_LL_UART_SHIFT)
#define UART_RBR (0x0 << DEBUG_LL_UART_SHIFT)
#define UART_DLL (0x0 << DEBUG_LL_UART_SHIFT)
#define UART_DLM (0x1 << DEBUG_LL_UART_SHIFT)
#define UART_LCR (0x3 << DEBUG_LL_UART_SHIFT)
#define UART_LSR (0x5 << DEBUG_LL_UART_SHIFT)
#define UART_LCR_W 0x07 /* Set UART to 8,N,2 & DLAB = 0 */
#define UART_LCR_DLAB 0x87 /* Set UART to 8,N,2 & DLAB = 1 */
#define UART_LSR_DR 0x01 /* UART received data present */
#define UART_LSR_THRE 0x20 /* Xmit holding register empty */
#ifndef __ASSEMBLY__
/*
* C macros
*/
#include <asm/io.h>
static inline void PUTC_LL(char ch)
{
#ifdef CONFIG_DEBUG_LL
while (!(__raw_readb((u8 *)DEBUG_LL_UART_ADDR + UART_LSR) & UART_LSR_THRE))
;
__raw_writeb(ch, (u8 *)DEBUG_LL_UART_ADDR + UART_THR);
#endif /* CONFIG_DEBUG_LL */
}
#else /* __ASSEMBLY__ */
/*
* Macros for use in assembly language code
*/
.macro debug_ll_ns16550_init
#ifdef CONFIG_DEBUG_LL
la t0, DEBUG_LL_UART_ADDR
li t1, UART_LCR_DLAB /* DLAB on */
sb t1, UART_LCR(t0) /* Write it out */
li t1, DEBUG_LL_UART_DIVISOR
sb t1, UART_DLL(t0) /* write low order byte */
srl t1, t1, 8
sb t1, UART_DLM(t0) /* write high order byte */
li t1, UART_LCR_W /* DLAB off */
sb t1, UART_LCR(t0) /* Write it out */
#endif /* CONFIG_DEBUG_LL */
.endm
/*
* output a character in a0
*/
.macro debug_ll_outc_a0
#ifdef CONFIG_DEBUG_LL
.set push
.set reorder
la t0, DEBUG_LL_UART_ADDR
201: lbu t1, UART_LSR(t0) /* get line status */
andi t1, t1, UART_LSR_THRE /* check for transmitter empty */
beqz t1, 201b /* try again */
sb a0, UART_THR(t0) /* write the character */
.set pop
#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
/*
* output CR + NL
*/
.macro debug_ll_ns16550_outnl
#ifdef CONFIG_DEBUG_LL
debug_ll_outc '\r'
debug_ll_outc '\n'
#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
.set push
.set reorder
la t0, DEBUG_LL_UART_ADDR
/* get line status and check for data present */
lbu t1, UART_LSR(t0)
andi v0, t1, UART_LSR_DR
.set pop
#endif /* CONFIG_DEBUG_LL */
.endm
/*
* get character to v0
*/
.macro debug_ll_getc
#ifdef CONFIG_DEBUG_LL
.set push
.set reorder
204:
debug_ll_tstc
/* try again */
beqz v0, 204b
/* read a character */
lbu v0, UART_RBR(t0)
.set pop
#endif /* CONFIG_DEBUG_LL */
.endm
#endif /* __ASSEMBLY__ */
#endif /* __INCLUDE_MIPS_ASM_DEBUG_LL_NS16550_H__ */
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