mail archive of the barebox mailing list
 help / color / mirror / Atom feed
From: Antony Pavlov <antonynpavlov@gmail.com>
To: barebox@lists.infradead.org
Subject: [PATCH v3 03/10] RISC-V: add low-level debug macros for ns16550
Date: Tue, 18 Dec 2018 10:19:36 +0300	[thread overview]
Message-ID: <20181218071943.2560-4-antonynpavlov@gmail.com> (raw)
In-Reply-To: <20181218071943.2560-1-antonynpavlov@gmail.com>

This patch adds macros for ns16550 port initialization
and single char output. The macros can be used in
MIPS asm pbl code.

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
---
 arch/riscv/include/asm/debug_ll_ns16550.h | 182 ++++++++++++++++++++++
 1 file changed, 182 insertions(+)

diff --git a/arch/riscv/include/asm/debug_ll_ns16550.h b/arch/riscv/include/asm/debug_ll_ns16550.h
new file mode 100644
index 0000000000..e891cbda25
--- /dev/null
+++ b/arch/riscv/include/asm/debug_ll_ns16550.h
@@ -0,0 +1,182 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2016, 2017 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.
+ *
+ */
+
+/** @file
+ *  This file contains declaration for early output support
+ */
+#ifndef __INCLUDE_RISCV_ASM_DEBUG_LL_NS16550_H__
+#define __INCLUDE_RISCV_ASM_DEBUG_LL_NS16550_H__
+
+#include <linux/kconfig.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 */
+
+#if defined(DEBUG_LL_UART_IOSIZE32)
+#define UART_REG_L	lw
+#define UART_REG_S	sw
+#elif defined(DEBUG_LL_UART_IOSIZE8)
+#define UART_REG_L	lbu
+#define UART_REG_S	sb
+#else
+#error "Please define DEBUG_LL_UART_IOSIZE{8,32}"
+#endif
+
+#ifndef __ASSEMBLY__
+/*
+ * C macros
+ */
+
+#include <asm/io.h>
+
+static inline void PUTC_LL(char ch)
+{
+#ifdef CONFIG_DEBUG_LL
+	while (!(__raw_readl((u8 *)DEBUG_LL_UART_ADDR + UART_LSR) & UART_LSR_THRE))
+		;
+	__raw_writel(ch, (u8 *)DEBUG_LL_UART_ADDR + UART_THR);
+#endif /* CONFIG_DEBUG_LL */
+}
+
+static inline void debug_ll_ns16550_init(void)
+{
+#ifdef CONFIG_DEBUG_LL
+	__raw_writel(UART_LCR_DLAB, (u8 *)DEBUG_LL_UART_ADDR + UART_LCR);
+	__raw_writel(DEBUG_LL_UART_DIVISOR & 0xff, (u8 *)DEBUG_LL_UART_ADDR + UART_DLL);
+	__raw_writel((DEBUG_LL_UART_DIVISOR >> 8) & 0xff, (u8 *)DEBUG_LL_UART_ADDR + UART_DLM);
+	__raw_writel(UART_LCR_W, (u8 *)DEBUG_LL_UART_ADDR + UART_LCR);
+#endif /* CONFIG_DEBUG_LL */
+}
+#else /* __ASSEMBLY__ */
+/*
+ * Macros for use in assembly language code
+ */
+
+.macro	debug_ll_ns16550_init
+#ifdef CONFIG_DEBUG_LL
+	li	t0, DEBUG_LL_UART_ADDR
+
+	li	t1, UART_LCR_DLAB		/* DLAB on */
+	UART_REG_S	t1, UART_LCR(t0)		/* Write it out */
+
+	li	t1, DEBUG_LL_UART_DIVISOR
+	UART_REG_S	t1, UART_DLL(t0)		/* write low order byte */
+	srl	t1, t1, 8
+	UART_REG_S	t1, UART_DLM(t0)		/* write high order byte */
+
+	li	t1, UART_LCR_W			/* DLAB off */
+	UART_REG_S	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
+
+	li	t0, DEBUG_LL_UART_ADDR
+
+201:
+	UART_REG_L	t1, UART_LSR(t0)	/* get line status */
+	andi	t1, t1, UART_LSR_THRE	/* check for transmitter empty */
+	beqz	t1, 201b			/* try again */
+
+	UART_REG_S	a0, UART_THR(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
+
+/*
+ * 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
+	li      t0, DEBUG_LL_UART_ADDR
+
+	/* get line status and check for data present */
+	UART_REG_L	s0, UART_LSR(t0)
+	andi	s0, s0, UART_LSR_DR
+
+#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 */
+	UART_REG_L	s0, UART_RBR(t0)
+
+#endif /* CONFIG_DEBUG_LL */
+.endm
+#endif /* __ASSEMBLY__ */
+
+#endif /* __INCLUDE_RISCV_ASM_DEBUG_LL_NS16550_H__ */
-- 
2.20.0


_______________________________________________
barebox mailing list
barebox@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/barebox

  parent reply	other threads:[~2018-12-18  7:20 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-12-18  7:19 [PATCH v3 00/10] Add initial RISC-V architecture support Antony Pavlov
2018-12-18  7:19 ` [PATCH v3 01/10] " Antony Pavlov
2018-12-18  7:19 ` [PATCH v3 02/10] RISC-V: add Erizo SoC support Antony Pavlov
2018-12-18  7:19 ` Antony Pavlov [this message]
2018-12-18  8:33   ` [PATCH v3 03/10] RISC-V: add low-level debug macros for ns16550 Oleksij Rempel
2018-12-18  7:19 ` [PATCH v3 04/10] RISC-V: add nmon nano-monitor Antony Pavlov
2018-12-18  7:19 ` [PATCH v3 05/10] RISC-V: erizo: add DEBUG_LL support Antony Pavlov
2018-12-18  7:19 ` [PATCH v3 06/10] RISC-V: erizo: enable nmon Antony Pavlov
2018-12-18  7:19 ` [PATCH v3 07/10] RISC-V: erizo: add nmon image creation Antony Pavlov
2018-12-18  7:19 ` [PATCH v3 08/10] RISC-V: add erizo_generic_defconfig Antony Pavlov
2018-12-18  7:19 ` [PATCH v3 09/10] scripts: add nmon-loader Antony Pavlov
2019-08-11  9:59   ` Antony Pavlov
2019-08-12  7:41     ` Sascha Hauer
2019-08-12  9:01       ` Antony Pavlov
2018-12-18  7:19 ` [PATCH v3 10/10] Documentation: add RISC-V docs Antony Pavlov
2019-01-03 11:18 ` [PATCH v3 00/10] Add initial RISC-V architecture support Sascha Hauer
2019-01-04  8:47   ` Antony Pavlov
2019-01-07  7:54     ` Sascha Hauer

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20181218071943.2560-4-antonynpavlov@gmail.com \
    --to=antonynpavlov@gmail.com \
    --cc=barebox@lists.infradead.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox