[PATCH] powerpc: serial port discovery (#2)

This moves the discovery of legacy serial ports to a separate file,
makes it common to ppc32 and ppc64, and reworks it to use the new OF
address translators to get to the ports early. This new version can also
detect some PCI serial cards using legacy chips and will probably match
those discovered port with the default console choice.

Only ppc64 gets udbg still yet, unifying udbg isn't finished yet.

It also adds some speed-probing code to udbg so that the default console
can come up at the same speed it was set to by the firmware.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

2 files changed, 30 insertions, 52 deletions

diff --git a/arch/powerpc/platforms/pseries/lpar.c b/arch/powerpc/platforms/pseries/lpar.c
index cf1bc11b3346..cc0939d4cad1 100644
--- a/arch/powerpc/platforms/pseries/lpar.c
+++ b/arch/powerpc/platforms/pseries/lpar.c
@@ -24,6 +24,7 @@
 #include <linux/config.h>
 #include <linux/kernel.h>
 #include <linux/dma-mapping.h>
+#include <linux/console.h>
 #include <asm/processor.h>
 #include <asm/mmu.h>
 #include <asm/page.h>
@@ -191,7 +192,7 @@ static unsigned char udbg_getcLP(void)
 /* call this from early_init() for a working debug console on
  * vterm capable LPAR machines
  */
-void udbg_init_debug_lpar(void)
+void __init udbg_init_debug_lpar(void)
 {
         vtermno = 0;
         udbg_putc = udbg_putcLP;
@@ -200,63 +201,54 @@ void udbg_init_debug_lpar(void)
 }
 
 /* returns 0 if couldn't find or use /chosen/stdout as console */
-int find_udbg_vterm(void)
+void __init find_udbg_vterm(void)
 {
         struct device_node *stdout_node;
         u32 *termno;
         char *name;
-        int found = 0;
+        int add_console;
 
         /* find the boot console from /chosen/stdout */
         if (!of_chosen)
-                return 0;
+                return;
         name = (char *)get_property(of_chosen, "linux,stdout-path", NULL);
         if (name == NULL)
-                return 0;
+                return;
         stdout_node = of_find_node_by_path(name);
         if (!stdout_node)
-                return 0;
-
-        /* now we have the stdout node; figure out what type of device it is. */
+                return;
         name = (char *)get_property(stdout_node, "name", NULL);
         if (!name) {
                 printk(KERN_WARNING "stdout node missing 'name' property!\n");
                 goto out;
         }
+        /* The user has requested a console so this is already set up. */
+        add_console = !strstr(cmd_line, "console=");
 
-        if (strncmp(name, "vty", 3) == 0) {
-                if (device_is_compatible(stdout_node, "hvterm1")) {
-                        termno = (u32 *)get_property(stdout_node, "reg", NULL);
-                        if (termno) {
-                                vtermno = termno[0];
-                                udbg_putc = udbg_putcLP;
-                                udbg_getc = udbg_getcLP;
-                                udbg_getc_poll = udbg_getc_pollLP;
-                                found = 1;
-                        }
-                } else if (device_is_compatible(stdout_node, "hvterm-protocol")) {
-                        termno = (u32 *)get_property(stdout_node, "reg", NULL);
-                        if (termno) {
-                                vtermno = termno[0];
-                                udbg_putc = udbg_hvsi_putc;
-                                udbg_getc = udbg_hvsi_getc;
-                                udbg_getc_poll = udbg_hvsi_getc_poll;
-                                found = 1;
-                        }
-                }
-        } else if (strncmp(name, "serial", 6)) {
-                /* XXX fix ISA serial console */
-                printk(KERN_WARNING "serial stdout on LPAR ('%s')! "
-                                "can't print udbg messages\n",
-                       stdout_node->full_name);
-        } else {
-                printk(KERN_WARNING "don't know how to print to stdout '%s'\n",
-                       stdout_node->full_name);
+        /* Check if it's a virtual terminal */
+        if (strncmp(name, "vty", 3) != 0)
+                goto out;
+        termno = (u32 *)get_property(stdout_node, "reg", NULL);
+        if (termno == NULL)
+                goto out;
+        vtermno = termno[0];
+
+        if (device_is_compatible(stdout_node, "hvterm1")) {
+                udbg_putc = udbg_putcLP;
+                udbg_getc = udbg_getcLP;
+                udbg_getc_poll = udbg_getc_pollLP;
+                if (add_console)
+                        add_preferred_console("hvc", termno[0] & 0xff, NULL);
+        } else if (device_is_compatible(stdout_node, "hvterm-protocol")) {
+                vtermno = termno[0];
+                udbg_putc = udbg_hvsi_putc;
+                udbg_getc = udbg_hvsi_getc;
+                udbg_getc_poll = udbg_hvsi_getc_poll;
+                if (add_console)
+                        add_preferred_console("hvsi", termno[0] & 0xff, NULL);
         }
-
 out:
         of_node_put(stdout_node);
-        return found;
 }
 
 void vpa_init(int cpu)
diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index 8a4238a3757f..8828dc378c3e 100644
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -79,8 +79,6 @@
 extern void find_udbg_vterm(void);
 extern void system_reset_fwnmi(void);   /* from head.S */
 extern void machine_check_fwnmi(void);  /* from head.S */
-extern void generic_find_legacy_serial_ports(u64 *physport,
-                unsigned int *default_speed);
 
 int fwnmi_active;  /* TRUE if an FWNMI handler is present */
 
@@ -366,10 +364,7 @@ static int pseries_set_xdabr(unsigned long dabr)
  */
 static void __init pSeries_init_early(void)
 {
-        void *comport;
         int iommu_off = 0;
-        unsigned int default_speed;
-        u64 physport;
 
         DBG(" -> pSeries_init_early()\n");
 
@@ -383,17 +378,8 @@ static void __init pSeries_init_early(void)
                              get_property(of_chosen, "linux,iommu-off", NULL));
         }
 
-        generic_find_legacy_serial_ports(&physport, &default_speed);
-
         if (platform_is_lpar())
                 find_udbg_vterm();
-        else if (physport) {
-                /* Map the uart for udbg. */
-                comport = (void *)ioremap(physport, 16);
-                udbg_init_uart(comport, default_speed);
-
-                DBG("Hello World !\n");
-        }
 
         if (firmware_has_feature(FW_FEATURE_DABR))
                 ppc_md.set_dabr = pseries_set_dabr;