[PATCH] ppc64: Use preferred_console to select a reasonable default console

From: Anton Blanchard <anton@samba.org>

Lets make a decent attempt to find out where your console is.  The new
preferred_console stuff is pretty nice.

diff --git a/arch/ppc64/kernel/setup.c b/arch/ppc64/kernel/setup.c
index 9f4d27328b16bdff11927e5e6fa48ceae60f63ed..27292d6cfd2a854b66381164b321ee8abe438dcb 100644 (file)
--- a/arch/ppc64/kernel/setup.c
+++ b/arch/ppc64/kernel/setup.c
@@ -38,6 +38,7 @@
 #include <asm/paca.h>
 #include <asm/ppcdebug.h>
 #include <asm/time.h>
+#include <asm/cputable.h>
 #include <asm/sections.h>
 
 extern unsigned long klimit;
@@ -430,8 +431,58 @@ void parse_cmd_line(unsigned long r3, unsigned long r4, unsigned long r5,
        }
 }
 
-
 #ifdef CONFIG_PPC_PSERIES
+static int __init set_preferred_console(void)
+{
+       struct device_node *prom_stdout;
+       char *name;
+
+       /* The user has requested a console so this is already set up. */
+       if (strstr(cmd_line, "console="))
+               return -EBUSY;
+
+       prom_stdout = find_path_device(of_stdout_device);
+       if (!prom_stdout)
+               return -ENODEV;
+
+       name = (char *)get_property(prom_stdout, "name", NULL);
+       if (!name)
+               return -ENODEV;
+
+       if (strcmp(name, "serial") == 0) {
+               int i;
+               u32 *reg = (u32 *)get_property(prom_stdout, "reg", &i);
+               if (i > 8) {
+                       int offset;
+                       switch (reg[1]) {
+                               case 0x3f8:
+                                       offset = 0;
+                                       break;
+                               case 0x2f8:
+                                       offset = 1;
+                                       break;
+                               case 0x898:
+                                       offset = 2;
+                                       break;
+                               case 0x890:
+                                       offset = 3;
+                                       break;
+                               default:
+                                       /* We dont recognise the serial port */
+                                       return -ENODEV;
+                       }
+
+                       return add_preferred_console("ttyS", offset, NULL);
+               }
+       } else if (strcmp(name, "vty") == 0) {
+               /* pSeries LPAR virtual console */
+               return add_preferred_console("hvc", 0, NULL);
+       }
+
+       return -ENODEV;
+}
+console_initcall(set_preferred_console);
+
 int parse_bootinfo(void)
 {
        struct bi_record *rec;