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authorJohn Crispin <blogic@openwrt.org>2013-01-20 22:02:55 +0100
committerJohn Crispin <blogic@openwrt.org>2013-02-17 01:25:31 +0100
commit5fff610b7c60195de98e68bec00c357f393ce634 (patch)
tree408b0dfb4bd006bd626246d69c3f4ce0b687c386
parent3a5bfe7bdbfd37c9206d7c6dfd7eb9664ccc5038 (diff)
MIPS: ralink: adds early_printk support
Add the code needed to make early printk work. Signed-off-by: John Crispin <blogic@openwrt.org> Signed-off-by: Gabor Juhos <juhosg@openwrt.org> Patchwork: http://patchwork.linux-mips.org/patch/4897/
-rw-r--r--arch/mips/ralink/early_printk.c44
1 files changed, 44 insertions, 0 deletions
diff --git a/arch/mips/ralink/early_printk.c b/arch/mips/ralink/early_printk.c
new file mode 100644
index 00000000000..c4ae47eb24a
--- /dev/null
+++ b/arch/mips/ralink/early_printk.c
@@ -0,0 +1,44 @@
+/*
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ *
+ * Copyright (C) 2011-2012 Gabor Juhos <juhosg@openwrt.org>
+ */
+
+#include <linux/io.h>
+#include <linux/serial_reg.h>
+
+#include <asm/addrspace.h>
+
+#define EARLY_UART_BASE 0x10000c00
+
+#define UART_REG_RX 0x00
+#define UART_REG_TX 0x04
+#define UART_REG_IER 0x08
+#define UART_REG_IIR 0x0c
+#define UART_REG_FCR 0x10
+#define UART_REG_LCR 0x14
+#define UART_REG_MCR 0x18
+#define UART_REG_LSR 0x1c
+
+static __iomem void *uart_membase = (__iomem void *) KSEG1ADDR(EARLY_UART_BASE);
+
+static inline void uart_w32(u32 val, unsigned reg)
+{
+ __raw_writel(val, uart_membase + reg);
+}
+
+static inline u32 uart_r32(unsigned reg)
+{
+ return __raw_readl(uart_membase + reg);
+}
+
+void prom_putchar(unsigned char ch)
+{
+ while ((uart_r32(UART_REG_LSR) & UART_LSR_THRE) == 0)
+ ;
+ uart_w32(ch, UART_REG_TX);
+ while ((uart_r32(UART_REG_LSR) & UART_LSR_THRE) == 0)
+ ;
+}