Merge branch 'tracking-integration-linux-vexpress' into merge-linux-linaro-lsklsk-20130505.0

1 files changed, 35 insertions, 0 deletions

diff --git a/arch/arm64/kernel/early_printk.c b/arch/arm64/kernel/early_printk.c
index 7e320a2edb9..ac974f48a7a 100644
--- a/arch/arm64/kernel/early_printk.c
+++ b/arch/arm64/kernel/early_printk.c
@@ -24,6 +24,7 @@
 #include <linux/io.h>
 
 #include <linux/amba/serial.h>
+#include <linux/serial_reg.h>
 
 static void __iomem *early_base;
 static void (*printch)(char ch);
@@ -40,6 +41,37 @@ static void pl011_printch(char ch)
 		;
 }
 
+/*
+ * Semihosting-based debug console
+ */
+static void smh_printch(char ch)
+{
+	asm volatile("mov  x1, %0\n"
+		     "mov  x0, #3\n"
+		     "hlt  0xf000\n"
+		     : : "r" (&ch) : "x0", "x1", "memory");
+}
+
+/*
+ * 8250/16550 (8-bit aligned registers) single character TX.
+ */
+static void uart8250_8bit_printch(char ch)
+{
+	while (!(readb_relaxed(early_base + UART_LSR) & UART_LSR_THRE))
+		;
+	writeb_relaxed(ch, early_base + UART_TX);
+}
+
+/*
+ * 8250/16550 (32-bit aligned registers) single character TX.
+ */
+static void uart8250_32bit_printch(char ch)
+{
+	while (!(readl_relaxed(early_base + (UART_LSR << 2)) & UART_LSR_THRE))
+		;
+	writel_relaxed(ch, early_base + (UART_TX << 2));
+}
+
 struct earlycon_match {
 	const char *name;
 	void (*printch)(char ch);
@@ -47,6 +79,9 @@ struct earlycon_match {
 
 static const struct earlycon_match earlycon_match[] __initconst = {
 	{ .name = "pl011", .printch = pl011_printch, },
+	{ .name = "smh", .printch = smh_printch, },
+	{ .name = "uart8250-8bit", .printch = uart8250_8bit_printch, },
+	{ .name = "uart8250-32bit", .printch = uart8250_32bit_printch, },
 	{}
 };