diff options
Diffstat (limited to 'arch/mips/ath79/early_printk.c')
| -rw-r--r-- | arch/mips/ath79/early_printk.c | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/arch/mips/ath79/early_printk.c b/arch/mips/ath79/early_printk.c new file mode 100644 index 000000000000..7499b0e9df26 --- /dev/null +++ b/arch/mips/ath79/early_printk.c @@ -0,0 +1,36 @@ +/* + * Atheros AR71XX/AR724X/AR913X SoC early printk support + * + * Copyright (C) 2008-2010 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/serial_reg.h> +#include <asm/addrspace.h> + +#include <asm/mach-ath79/ar71xx_regs.h> + +static inline void prom_wait_thre(void __iomem *base) +{ + u32 lsr; + + do { + lsr = __raw_readl(base + UART_LSR * 4); + if (lsr & UART_LSR_THRE) + break; + } while (1); +} + +void prom_putchar(unsigned char ch) +{ + void __iomem *base = (void __iomem *)(KSEG1ADDR(AR71XX_UART_BASE)); + + prom_wait_thre(base); + __raw_writel(ch, base + UART_TX * 4); + prom_wait_thre(base); +} |