ARM: brcmstb: Add earlyprintk support using run-time checks

The SUN_TOP_CTRL_FAMILY_ID register  is at a fixed absolute address for
all of our supported chips, so utilize its value to determine what the
UARTA base address should be based on the value we read.

Since the code is called both during decompressor when the MMU is off,
and after the MMU has been turned on in the kernel, and we want to do
the lookup only once, we use the same technique as tegra.S and have a
shared storage location between the decompressor and the kernel.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>

arch/arm/mach-bcm/brcmstb.c

@@ -19,6 +19,22 @@
 #include <asm/mach-types.h>
 #include <asm/mach/arch.h>
 
+/*
+ * Storage for debug-macro.S's state.
+ *
+ * This must be in .data not .bss so that it gets initialized each time the
+ * kernel is loaded. The data is declared here rather than debug-macro.S so
+ * that multiple inclusions of debug-macro.S point at the same data.
+ */
+u32 brcmstb_uart_config[3] = {
+	/* Debug UART initialization required */
+	1,
+	/* Debug UART physical address */
+	0,
+	/* Debug UART virtual address */
+	0,
+};
+
 static void __init brcmstb_init_irq(void)
 {
 	irqchip_init();