sh: More flexible + SH7780 earlyprintk SCIF support.

This makes the early printk support somewhat more flexible,
moving the port definition to a config option, and making the
port initialization configurable for sh-ipl+g users.

At the same time, this allows us to trivially wire up the
SH7780 SCIF0, so that's thrown in too more or less for free.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

2 files changed, 38 insertions, 24 deletions

diff --git a/arch/sh/Kconfig.debug b/arch/sh/Kconfig.debug
index 48479e0..dcceec9 100644
--- a/arch/sh/Kconfig.debug
+++ b/arch/sh/Kconfig.debug
@@ -17,7 +17,18 @@ config SH_STANDARD_BIOS
 
 config EARLY_SCIF_CONSOLE
 	bool "Use early SCIF console"
-	depends on CPU_SH4 || CPU_SH2A && !SH_STANDARD_BIOS
+	help
+	  This enables an early console using a fixed SCIF port. This can
+	  be used by platforms that are either not running the SH
+	  standard BIOS, or do not wish to use the BIOS callbacks for the
+	  serial I/O.
+
+config EARLY_SCIF_CONSOLE_PORT
+	hex "SCIF port for early console"
+	depends on EARLY_SCIF_CONSOLE
+	default "0xffe00000" if CPU_SUBTYPE_SH7780
+	default "0xfffe9800" if CPU_SUBTYPE_SH72060
+	default "0xffe80000" if CPU_SH4
 
 config EARLY_PRINTK
 	bool "Early printk support"
@@ -30,6 +41,11 @@ config EARLY_PRINTK
 	  when the kernel may crash or hang before the serial console is
 	  initialised. If unsure, say N.
 
+	  On devices that are running SH-IPL and want to keep the port
+	  initialization consistent while not using the BIOS callbacks,
+	  select both the EARLY_SCIF_CONSOLE and SH_STANDARD_BIOS, using
+	  the kernel command line option to toggle back and forth.
+
 config DEBUG_STACKOVERFLOW
 	bool "Check for stack overflows"
 	depends on DEBUG_KERNEL
diff --git a/arch/sh/kernel/early_printk.c b/arch/sh/kernel/early_printk.c
index a000227..6034082 100644
--- a/arch/sh/kernel/early_printk.c
+++ b/arch/sh/kernel/early_printk.c
@@ -12,7 +12,7 @@
 #include <linux/console.h>
 #include <linux/tty.h>
 #include <linux/init.h>
-#include <asm/io.h>
+#include <linux/io.h>
 
 #ifdef CONFIG_SH_STANDARD_BIOS
 #include <asm/sh_bios.h>
@@ -62,17 +62,9 @@ static struct console bios_console = {
 #include <linux/serial_core.h>
 #include "../../../drivers/serial/sh-sci.h"
 
-#ifdef CONFIG_CPU_SH4
-#define SCIF_REG	0xffe80000
-#elif defined(CONFIG_CPU_SUBTYPE_SH72060)
-#define SCIF_REG	0xfffe9800
-#else
-#error "Undefined SCIF for this subtype"
-#endif
-
 static struct uart_port scif_port = {
-	.mapbase	= SCIF_REG,
-	.membase	= (char __iomem *)SCIF_REG,
+	.mapbase	= CONFIG_EARLY_SCIF_CONSOLE_PORT,
+	.membase	= (char __iomem *)CONFIG_EARLY_SCIF_CONSOLE_PORT,
 };
 
 static void scif_sercon_putc(int c)
@@ -113,23 +105,29 @@ static struct console scif_console = {
 	.index		= -1,
 };
 
+#if defined(CONFIG_CPU_SH4) && !defined(CONFIG_SH_STANDARD_BIOS)
+/*
+ * Simple SCIF init, primarily aimed at SH7750 and other similar SH-4
+ * devices that aren't using sh-ipl+g.
+ */
 static void scif_sercon_init(int baud)
 {
-	ctrl_outw(0, SCIF_REG + 8);
-	ctrl_outw(0, SCIF_REG);
+	ctrl_outw(0, scif_port.mapbase + 8);
+	ctrl_outw(0, scif_port.mapbase);
 
 	/* Set baud rate */
 	ctrl_outb((CONFIG_SH_PCLK_FREQ + 16 * baud) /
-		  (32 * baud) - 1, SCIF_REG + 4);
-
-	ctrl_outw(12, SCIF_REG + 24);
-	ctrl_outw(8, SCIF_REG + 24);
-	ctrl_outw(0, SCIF_REG + 32);
-	ctrl_outw(0x60, SCIF_REG + 16);
-	ctrl_outw(0, SCIF_REG + 36);
-	ctrl_outw(0x30, SCIF_REG + 8);
+		  (32 * baud) - 1, scif_port.mapbase + 4);
+
+	ctrl_outw(12, scif_port.mapbase + 24);
+	ctrl_outw(8, scif_port.mapbase + 24);
+	ctrl_outw(0, scif_port.mapbase + 32);
+	ctrl_outw(0x60, scif_port.mapbase + 16);
+	ctrl_outw(0, scif_port.mapbase + 36);
+	ctrl_outw(0x30, scif_port.mapbase + 8);
 }
-#endif
+#endif /* CONFIG_CPU_SH4 && !CONFIG_SH_STANDARD_BIOS */
+#endif /* CONFIG_EARLY_SCIF_CONSOLE */
 
 /*
  * Setup a default console, if more than one is compiled in, rely on the
@@ -168,7 +166,7 @@ int __init setup_early_printk(char *opt)
 	if (!strncmp(buf, "serial", 6)) {
 		early_console = &scif_console;
 
-#ifdef CONFIG_CPU_SH4
+#if defined(CONFIG_CPU_SH4) && !defined(CONFIG_SH_STANDARD_BIOS)
 		scif_sercon_init(115200);
 #endif
 	}