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authorJiaxun Yang <jiaxun.yang@flygoat.com>2019-10-20 17:43:14 +0300
committerPaul Burton <paulburton@kernel.org>2019-11-02 00:30:52 +0300
commit71e2f4dd5a65bd8dbca0b77661e75eea471168f8 (patch)
treee7107d2996f7ba8ec282190a49c557598acd6f88 /arch/mips/loongson2ef/common/early_printk.c
parent268a2d60013049cfd9a0aada77284aa6ea8ad26a (diff)
downloadlinux-71e2f4dd5a65bd8dbca0b77661e75eea471168f8.tar.xz
MIPS: Fork loongson2ef from loongson64
As later model of GSx64 family processors including 2-series-soc have similar design with initial loongson3a while loongson2e/f seems less identical, we separate loongson2e/f support code out of mach-loongson64 to make our life easier. This patch contains mostly file moving works. Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com> [paulburton@kernel.org: Squash in the MAINTAINERS updates] Signed-off-by: Paul Burton <paulburton@kernel.org> Cc: linux-mips@vger.kernel.org Cc: paul.burton@mips.com
Diffstat (limited to 'arch/mips/loongson2ef/common/early_printk.c')
-rw-r--r--arch/mips/loongson2ef/common/early_printk.c38
1 files changed, 38 insertions, 0 deletions
diff --git a/arch/mips/loongson2ef/common/early_printk.c b/arch/mips/loongson2ef/common/early_printk.c
new file mode 100644
index 000000000000..5e2a151aa30c
--- /dev/null
+++ b/arch/mips/loongson2ef/common/early_printk.c
@@ -0,0 +1,38 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* early printk support
+ *
+ * Copyright (c) 2009 Philippe Vachon <philippe@cowpig.ca>
+ * Copyright (c) 2009 Lemote Inc.
+ * Author: Wu Zhangjin, wuzhangjin@gmail.com
+ */
+#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);
+}