MIPS: ath79: Add early printk support for the AR933X SoCs
The AR933X SoCs are using a different UART, thus require
different code for early printk support.
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Cc: linux-mips@linux-mips.org
Cc: Kathy Giori <kgiori@qca.qualcomm.com>
Cc: "Luis R. Rodriguez" <rodrigue@qca.qualcomm.com>
Patchwork: https://patchwork.linux-mips.org/patch/2521/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/ath79/early_printk.c b/arch/mips/ath79/early_printk.c
index 7499b0e..6a51ced 100644
--- a/arch/mips/ath79/early_printk.c
+++ b/arch/mips/ath79/early_printk.c
@@ -1,7 +1,7 @@
/*
- * Atheros AR71XX/AR724X/AR913X SoC early printk support
+ * Atheros AR7XXX/AR9XXX SoC early printk support
*
- * Copyright (C) 2008-2010 Gabor Juhos <juhosg@openwrt.org>
+ * 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
@@ -10,27 +10,85 @@
*/
#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 inline void prom_wait_thre(void __iomem *base)
+static void (*_prom_putchar) (unsigned char);
+
+static inline void prom_putchar_wait(void __iomem *reg, u32 mask, u32 val)
{
- u32 lsr;
+ u32 t;
do {
- lsr = __raw_readl(base + UART_LSR * 4);
- if (lsr & UART_LSR_THRE)
+ t = __raw_readl(reg);
+ if ((t & mask) == val)
break;
} while (1);
}
-void prom_putchar(unsigned char ch)
+static void prom_putchar_ar71xx(unsigned char ch)
{
void __iomem *base = (void __iomem *)(KSEG1ADDR(AR71XX_UART_BASE));
- prom_wait_thre(base);
+ prom_putchar_wait(base + UART_LSR * 4, UART_LSR_THRE, UART_LSR_THRE);
__raw_writel(ch, base + UART_TX * 4);
- prom_wait_thre(base);
+ 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);
}