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 48479e014dac..dcceec95a2d5 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 a00022722e9e..60340823798a 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
         }