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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
commit76cb841cb886eef6b3bee341a2266c76578724ad (patch)
treef5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /arch/mips/loongson64/common/early_printk.c
parentInitial commit. (diff)
downloadlinux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz
linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip
Adding upstream version 4.19.249.upstream/4.19.249
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/mips/loongson64/common/early_printk.c')
-rw-r--r--arch/mips/loongson64/common/early_printk.c42
1 files changed, 42 insertions, 0 deletions
diff --git a/arch/mips/loongson64/common/early_printk.c b/arch/mips/loongson64/common/early_printk.c
new file mode 100644
index 000000000..a782e2b24
--- /dev/null
+++ b/arch/mips/loongson64/common/early_printk.c
@@ -0,0 +1,42 @@
+/* early printk support
+ *
+ * Copyright (c) 2009 Philippe Vachon <philippe@cowpig.ca>
+ * Copyright (c) 2009 Lemote Inc.
+ * Author: Wu Zhangjin, wuzhangjin@gmail.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/serial_reg.h>
+#include <asm/setup.h>
+
+#include <loongson.h>
+
+#define PORT(base, offset) (u8 *)(base + offset)
+
+static inline unsigned int serial_in(unsigned char *base, int offset)
+{
+ return readb(PORT(base, offset));
+}
+
+static inline void serial_out(unsigned char *base, int offset, int value)
+{
+ writeb(value, PORT(base, offset));
+}
+
+void prom_putchar(char c)
+{
+ int timeout;
+ unsigned char *uart_base;
+
+ uart_base = (unsigned char *)_loongson_uart_base[0];
+ timeout = 1024;
+
+ while (((serial_in(uart_base, UART_LSR) & UART_LSR_THRE) == 0) &&
+ (timeout-- > 0))
+ ;
+
+ serial_out(uart_base, UART_TX, c);
+}