diff options
Diffstat (limited to 'arch/riscv/include/asm/debug_ll_litex.h')
| -rw-r--r-- | arch/riscv/include/asm/debug_ll_litex.h | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/arch/riscv/include/asm/debug_ll_litex.h b/arch/riscv/include/asm/debug_ll_litex.h new file mode 100644 index 0000000000..2fcdd9b0ec --- /dev/null +++ b/arch/riscv/include/asm/debug_ll_litex.h @@ -0,0 +1,123 @@ +/* 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 s0, UART_RXEMPTY(t0) + bnez s0, 243f + li s0, 1 + j 244f +243: li s0, 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 s0, 204b + + /* read a character */ + lb s0, 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__ */ |