1 files changed, 94 insertions, 0 deletions
diff --git a/arch/mips/ath79/early_printk.c b/arch/mips/ath79/early_printk.c
new file mode 100644
index 00000000..6a51ced7
--- /dev/null
+++ b/arch/mips/ath79/early_printk.c
@@ -0,0 +1,94 @@
+/*
+ *  Atheros AR7XXX/AR9XXX SoC early printk support
+ *
+ *  Copyright (C) 2008-2011 Gabor Juhos <juhosg@openwrt.org>
+ *  Copyright (C) 2008 Imre Kaloz <kaloz@openwrt.org>
+ *
+ *  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.
+ */
+
+#include <linux/io.h>
+#include <linux/errno.h>
+#include <linux/serial_reg.h>
+#include <asm/addrspace.h>
+
+#include <asm/mach-ath79/ath79.h>
+#include <asm/mach-ath79/ar71xx_regs.h>
+#include <asm/mach-ath79/ar933x_uart.h>
+
+static void (*_prom_putchar) (unsigned char);
+
+static inline void prom_putchar_wait(void __iomem *reg, u32 mask, u32 val)
+{
+	u32 t;
+
+	do {
+		t = __raw_readl(reg);
+		if ((t & mask) == val)
+			break;
+	} while (1);
+}
+
+static void prom_putchar_ar71xx(unsigned char ch)
+{
+	void __iomem *base = (void __iomem *)(KSEG1ADDR(AR71XX_UART_BASE));
+
+	prom_putchar_wait(base + UART_LSR * 4, UART_LSR_THRE, UART_LSR_THRE);
+	__raw_writel(ch, base + UART_TX * 4);
+	prom_putchar_wait(base + UART_LSR * 4, UART_LSR_THRE, UART_LSR_THRE);
+}
+
+static void prom_putchar_ar933x(unsigned char ch)
+{
+	void __iomem *base = (void __iomem *)(KSEG1ADDR(AR933X_UART_BASE));
+
+	prom_putchar_wait(base + AR933X_UART_DATA_REG, AR933X_UART_DATA_TX_CSR,
+			  AR933X_UART_DATA_TX_CSR);
+	__raw_writel(AR933X_UART_DATA_TX_CSR | ch, base + AR933X_UART_DATA_REG);
+	prom_putchar_wait(base + AR933X_UART_DATA_REG, AR933X_UART_DATA_TX_CSR,
+			  AR933X_UART_DATA_TX_CSR);
+}
+
+static void prom_putchar_dummy(unsigned char ch)
+{
+	/* nothing to do */
+}
+
+static void prom_putchar_init(void)
+{
+	void __iomem *base;
+	u32 id;
+
+	base = (void __iomem *)(KSEG1ADDR(AR71XX_RESET_BASE));
+	id = __raw_readl(base + AR71XX_RESET_REG_REV_ID);
+	id &= REV_ID_MAJOR_MASK;
+
+	switch (id) {
+	case REV_ID_MAJOR_AR71XX:
+	case REV_ID_MAJOR_AR7240:
+	case REV_ID_MAJOR_AR7241:
+	case REV_ID_MAJOR_AR7242:
+	case REV_ID_MAJOR_AR913X:
+		_prom_putchar = prom_putchar_ar71xx;
+		break;
+
+	case REV_ID_MAJOR_AR9330:
+	case REV_ID_MAJOR_AR9331:
+		_prom_putchar = prom_putchar_ar933x;
+		break;
+
+	default:
+		_prom_putchar = prom_putchar_dummy;
+		break;
+	}
+}
+
+void prom_putchar(unsigned char ch)
+{
+	if (!_prom_putchar)
+		prom_putchar_init();
+
+	_prom_putchar(ch);
+}