[PATCH v4 03/16] [loongson] early_printk: add new implmentation

Wu Zhangjin
2009-07-02T15:20:45Z

From: Wu Zhangjin <wuzj@lemote.com>

This patch is based on the implementation in the lm2e-fixes branch of
Philippe's git://git.linux-cisco.org/linux-mips.git and the
malta-specific early_printk implementation.

Signed-off-by: Wu Zhangjin <wuzj@lemote.com>
---
arch/mips/lemote/lm2e/Makefile | 5 ++++
arch/mips/lemote/lm2e/early_printk.c | 41 ++++++++++++++++++++++++++++++++++
2 files changed, 46 insertions(+), 0 deletions(-)
create mode 100644 arch/mips/lemote/lm2e/early_printk.c

diff --git a/arch/mips/lemote/lm2e/Makefile b/arch/mips/lemote/lm2e/Makefile
index b0c0339..f191732 100644
--- a/arch/mips/lemote/lm2e/Makefile
+++ b/arch/mips/lemote/lm2e/Makefile
@@ -4,4 +4,9 @@

obj-y += setup.o prom.o reset.o irq.o pci.o bonito-irq.o mem.o

+#
+# Early printk support
+#
+obj-$(CONFIG_EARLY_PRINTK) += early_printk.o
+
EXTRA_CFLAGS += -Werror
diff --git a/arch/mips/lemote/lm2e/early_printk.c b/arch/mips/lemote/lm2e/early_printk.c
new file mode 100644
index 0000000..811c7de
--- /dev/null
+++ b/arch/mips/lemote/lm2e/early_printk.c
@@ -0,0 +1,41 @@
+/* early printk support
+ *
+ * Copyright (c) 2009 Philippe Vachon <philippe@cowpig.ca>
+ * Copyright (C) 2009 Lemote Inc. & Insititute of Computing Technology
+ * Author: Wu Zhangjin, wuzj@lemote.com
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+#include <linux/io.h>
+#include <linux/init.h>
+#include <linux/serial_reg.h>
+
+#include <asm/mips-boards/bonito64.h>
+
+#define UART_BASE (BONITO_PCIIO_BASE + 0x3f8)
+
+#define PORT(base, offset) (u8 *)(base + offset)
+
+static inline unsigned int serial_in(phys_addr_t base, int offset)
+{
+ return readb(PORT(base, offset));
+}
+
+static inline void serial_out(phys_addr_t base, int offset, int value)
+{
+ writeb(value, PORT(base, offset));
+}
+
+void prom_putchar(char c)
+{
+ phys_addr_t uart_base =
+ (phys_addr_t) ioremap_nocache(UART_BASE, 8);
+
+ while ((serial_in(uart_base, UART_LSR) & UART_LSR_THRE) == 0)
+ ;
+
+ serial_out(uart_base, UART_TX, c);
+}
--
1.6.2.1