sh: earlyprintk= support and cleanups.

Allow multiple early printk consoles via earlyprintk=.

With this change earlyprintk is no longer enabled by default,
it must be specified on the kernel command line. Optionally
with ,keep to prevent unreg by tty_io.

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

2 files changed, 98 insertions, 30 deletions

diff --git a/arch/sh/kernel/early_printk.c b/arch/sh/kernel/early_printk.c
index 1378db375e17..a00022722e9e 100644
--- a/arch/sh/kernel/early_printk.c
+++ b/arch/sh/kernel/early_printk.c
@@ -3,7 +3,7 @@
  *
  *  Copyright (C) 1999, 2000  Niibe Yutaka
  *  Copyright (C) 2002  M. R. Brown
- *  Copyright (C) 2004  Paul Mundt
+ *  Copyright (C) 2004 - 2006  Paul Mundt
  *
  * This file is subject to the terms and conditions of the GNU General Public
  * License.  See the file "COPYING" in the main directory of this archive
@@ -49,7 +49,7 @@ static int __init sh_console_setup(struct console *co, char *options)
         return 0;
 }
 
-static struct console early_console = {
+static struct console bios_console = {
         .name           = "bios",
         .write          = sh_console_write,
         .setup          = sh_console_setup,
@@ -59,34 +59,43 @@ static struct console early_console = {
 #endif
 
 #ifdef CONFIG_EARLY_SCIF_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,
+};
 
 static void scif_sercon_putc(int c)
 {
-        while (!(ctrl_inw(SCIF_REG + 0x10) & 0x20)) ;
+        while (((sci_in(&scif_port, SCFDR) & 0x1f00 >> 8) == 16))
+                ;
 
-        ctrl_outb(c, SCIF_REG + 12);
-        ctrl_outw((ctrl_inw(SCIF_REG + 0x10) & 0x9f), SCIF_REG + 0x10);
+        sci_out(&scif_port, SCxTDR, c);
+        sci_in(&scif_port, SCxSR);
+        sci_out(&scif_port, SCxSR, 0xf3 & ~(0x20 | 0x40));
+
+        while ((sci_in(&scif_port, SCxSR) & 0x40) == 0);
+                ;
 
         if (c == '\n')
                 scif_sercon_putc('\r');
 }
 
-static void scif_sercon_flush(void)
-{
-        ctrl_outw((ctrl_inw(SCIF_REG + 0x10) & 0xbf), SCIF_REG + 0x10);
-
-        while (!(ctrl_inw(SCIF_REG + 0x10) & 0x40)) ;
-
-        ctrl_outw((ctrl_inw(SCIF_REG + 0x10) & 0xbf), SCIF_REG + 0x10);
-}
-
-static void scif_sercon_write(struct console *con, const char *s, unsigned count)
+static void scif_sercon_write(struct console *con, const char *s,
+                              unsigned count)
 {
         while (count-- > 0)
                 scif_sercon_putc(*s++);
-
-        scif_sercon_flush();
 }
 
 static int __init scif_sercon_setup(struct console *con, char *options)
@@ -96,7 +105,7 @@ static int __init scif_sercon_setup(struct console *con, char *options)
         return 0;
 }
 
-static struct console early_console = {
+static struct console scif_console = {
         .name           = "sercon",
         .write          = scif_sercon_write,
         .setup          = scif_sercon_setup,
@@ -104,7 +113,7 @@ static struct console early_console = {
         .index          = -1,
 };
 
-void scif_sercon_init(int baud)
+static void scif_sercon_init(int baud)
 {
         ctrl_outw(0, SCIF_REG + 8);
         ctrl_outw(0, SCIF_REG);
@@ -122,16 +131,61 @@ void scif_sercon_init(int baud)
 }
 #endif
 
-void __init enable_early_printk(void)
+/*
+ * Setup a default console, if more than one is compiled in, rely on the
+ * earlyprintk= parsing to give priority.
+ */
+static struct console *early_console =
+#ifdef CONFIG_SH_STANDARD_BIOS
+        &bios_console
+#elif defined(CONFIG_EARLY_SCIF_CONSOLE)
+        &scif_console
+#else
+        NULL
+#endif
+        ;
+
+static int __initdata keep_early;
+
+int __init setup_early_printk(char *opt)
 {
-#ifdef CONFIG_EARLY_SCIF_CONSOLE
-        scif_sercon_init(115200);
+        char *space;
+        char buf[256];
+
+        strlcpy(buf, opt, sizeof(buf));
+        space = strchr(buf, ' ');
+        if (space)
+                *space = 0;
+
+        if (strstr(buf, "keep"))
+                keep_early = 1;
+
+#ifdef CONFIG_SH_STANDARD_BIOS
+        if (!strncmp(buf, "bios", 4))
+                early_console = &bios_console;
+#endif
+#if defined(CONFIG_EARLY_SCIF_CONSOLE)
+        if (!strncmp(buf, "serial", 6)) {
+                early_console = &scif_console;
+
+#ifdef CONFIG_CPU_SH4
+                scif_sercon_init(115200);
+#endif
+        }
 #endif
-        register_console(&early_console);
+
+        if (likely(early_console))
+                register_console(early_console);
+
+        return 1;
 }
+__setup("earlyprintk=", setup_early_printk);
 
-void disable_early_printk(void)
+void __init disable_early_printk(void)
 {
-        unregister_console(&early_console);
+        if (!keep_early) {
+                printk("disabling early console\n");
+                unregister_console(early_console);
+        } else
+                printk("keeping early console\n");
 }
-
diff --git a/arch/sh/kernel/setup.c b/arch/sh/kernel/setup.c
index e75189cb1db7..cff8d36f91b0 100644
--- a/arch/sh/kernel/setup.c
+++ b/arch/sh/kernel/setup.c
@@ -145,6 +145,24 @@ static inline void parse_cmdline (char ** cmdline_p, char mv_name[MV_NAME_SIZE],
                                 memory_end = memory_start + mem_size;
                         }
                 }
+
+#ifdef CONFIG_EARLY_PRINTK
+                if (c == ' ' && !memcmp(from, "earlyprintk=", 12)) {
+                        char *ep_end;
+
+                        if (to != command_line)
+                                to--;
+
+                        from += 12;
+                        ep_end = strchr(from, ' ');
+
+                        setup_early_printk(from);
+                        printk("early console enabled\n");
+
+                        from = ep_end;
+                }
+#endif
+
                 if (c == ' ' && !memcmp(from, "sh_mv=", 6)) {
                         char* mv_end;
                         char* mv_comma;
@@ -245,11 +263,7 @@ void __init setup_arch(char **cmdline_p)
         unsigned long bootmap_size;
         unsigned long start_pfn, max_pfn, max_low_pfn;
 
-#ifdef CONFIG_EARLY_PRINTK
-        extern void enable_early_printk(void);
 
-        enable_early_printk();
-#endif
 #ifdef CONFIG_CMDLINE_BOOL
         strcpy(COMMAND_LINE, CONFIG_CMDLINE);
 #endif