microblaze: Simplify early console binding from DT

Recognize early Linux console from chosen - linux,stdout-path
instead of detecting the first console with appropriate
compatible strings.
This patch solved the problem on system with multiple
consoles.

Signed-off-by: Michal Simek <monstr@monstr.eu>

3 files changed, 70 insertions, 82 deletions

diff --git a/arch/microblaze/include/asm/prom.h b/arch/microblaze/include/asm/prom.h
index d0890d36ef61..34c4e8b27805 100644
--- a/arch/microblaze/include/asm/prom.h
+++ b/arch/microblaze/include/asm/prom.h
@@ -26,8 +26,12 @@
 #define HAVE_ARCH_DEVTREE_FIXUPS
 
 /* Other Prototypes */
-extern int early_uartlite_console(void);
-extern int early_uart16550_console(void);
+enum early_consoles {
+        UARTLITE = 1,
+        UART16550 = 2,
+};
+
+extern int of_early_console(void *version);
 
 #ifdef CONFIG_PCI
 /*
diff --git a/arch/microblaze/kernel/early_printk.c b/arch/microblaze/kernel/early_printk.c
index 8f8384e98bf7..e21390da0a4d 100644
--- a/arch/microblaze/kernel/early_printk.c
+++ b/arch/microblaze/kernel/early_printk.c
@@ -127,45 +127,41 @@ void early_printk(const char *fmt, ...)
 
 int __init setup_early_printk(char *opt)
 {
+        int version = 0;
+
         if (early_console_initialized)
                 return 1;
 
-#ifdef CONFIG_SERIAL_UARTLITE_CONSOLE
-        base_addr = early_uartlite_console();
+        base_addr = of_early_console(&version);
         if (base_addr) {
-                early_console_initialized = 1;
 #ifdef CONFIG_MMU
                 early_console_reg_tlb_alloc(base_addr);
 #endif
-                early_console = &early_serial_uartlite_console;
-                early_printk("early_printk_console is enabled at 0x%08x\n",
-                                                        base_addr);
-
-                register_console(early_console);
-
-                return 0;
-        }
-#endif /* CONFIG_SERIAL_UARTLITE_CONSOLE */
-
+                switch (version) {
+#ifdef CONFIG_SERIAL_UARTLITE_CONSOLE
+                case UARTLITE:
+                        printk(KERN_INFO "Early console on uartlite "
+                                                "at 0x%08x\n", base_addr);
+                        early_console = &early_serial_uartlite_console;
+                        break;
+#endif
 #ifdef CONFIG_SERIAL_8250_CONSOLE
-        base_addr = early_uart16550_console();
-        base_addr &= ~3; /* clear register offset */
-        if (base_addr) {
-                early_console_initialized = 1;
-#ifdef CONFIG_MMU
-                early_console_reg_tlb_alloc(base_addr);
+                case UART16550:
+                        printk(KERN_INFO "Early console on uart16650 "
+                                                "at 0x%08x\n", base_addr);
+                        early_console = &early_serial_uart16550_console;
+                        break;
 #endif
-                early_console = &early_serial_uart16550_console;
-
-                early_printk("early_printk_console is enabled at 0x%08x\n",
-                                                        base_addr);
+                default:
+                        printk(KERN_INFO  "Unsupported early console %d\n",
+                                                                version);
+                        return 1;
+                }
 
                 register_console(early_console);
-
+                early_console_initialized = 1;
                 return 0;
         }
-#endif /* CONFIG_SERIAL_8250_CONSOLE */
-
         return 1;
 }
 
diff --git a/arch/microblaze/kernel/prom.c b/arch/microblaze/kernel/prom.c
index b15cc219b1d9..18d9371d9b26 100644
--- a/arch/microblaze/kernel/prom.c
+++ b/arch/microblaze/kernel/prom.c
@@ -53,69 +53,57 @@ void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
 }
 
 #ifdef CONFIG_EARLY_PRINTK
-/* MS this is Microblaze specifig function */
-static int __init early_init_dt_scan_serial(unsigned long node,
-                                const char *uname, int depth, void *data)
-{
-        unsigned long l;
-        char *p;
-        const __be32 *addr;
-
-        pr_debug("search \"serial\", depth: %d, uname: %s\n", depth, uname);
-
-/* find all serial nodes */
-        if (strncmp(uname, "serial", 6) != 0)
-                return 0;
-
-/* find compatible node with uartlite */
-        p = of_get_flat_dt_prop(node, "compatible", &l);
-        if ((strncmp(p, "xlnx,xps-uartlite", 17) != 0) &&
-                        (strncmp(p, "xlnx,opb-uartlite", 17) != 0) &&
-                        (strncmp(p, "xlnx,axi-uartlite", 17) != 0))
-                return 0;
-
-        addr = of_get_flat_dt_prop(node, "reg", &l);
-        return be32_to_cpup(addr); /* return address */
-}
+char *stdout;
 
-/* this function is looking for early uartlite console - Microblaze specific */
-int __init early_uartlite_console(void)
-{
-        return of_scan_flat_dt(early_init_dt_scan_serial, NULL);
-}
-
-/* MS this is Microblaze specifig function */
-static int __init early_init_dt_scan_serial_full(unsigned long node,
+int __init early_init_dt_scan_chosen_serial(unsigned long node,
                                 const char *uname, int depth, void *data)
 {
         unsigned long l;
         char *p;
-        unsigned int addr;
-
-        pr_debug("search \"chosen\", depth: %d, uname: %s\n", depth, uname);
-
-/* find all serial nodes */
-        if (strncmp(uname, "serial", 6) != 0)
-                return 0;
 
-        early_init_dt_check_for_initrd(node);
-
-/* find compatible node with uartlite */
-        p = of_get_flat_dt_prop(node, "compatible", &l);
-
-        if ((strncmp(p, "xlnx,xps-uart16550", 18) != 0) &&
-                (strncmp(p, "xlnx,axi-uart16550", 18) != 0))
-                return 0;
-
-        addr = *(u32 *)of_get_flat_dt_prop(node, "reg", &l);
-        addr += *(u32 *)of_get_flat_dt_prop(node, "reg-offset", &l);
-        return be32_to_cpu(addr); /* return address */
+        pr_debug("%s: depth: %d, uname: %s\n", __func__, depth, uname);
+
+        if (depth == 1 && (strcmp(uname, "chosen") == 0 ||
+                                strcmp(uname, "chosen@0") == 0)) {
+                p = of_get_flat_dt_prop(node, "linux,stdout-path", &l);
+                if (p != NULL && l > 0)
+                        stdout = p; /* store pointer to stdout-path */
+        }
+
+        if (stdout && strstr(stdout, uname)) {
+                p = of_get_flat_dt_prop(node, "compatible", &l);
+                pr_debug("Compatible string: %s\n", p);
+
+                if ((strncmp(p, "xlnx,xps-uart16550", 18) == 0) ||
+                        (strncmp(p, "xlnx,axi-uart16550", 18) == 0)) {
+                        unsigned int addr;
+
+                        *(u32 *)data = UART16550;
+
+                        addr = *(u32 *)of_get_flat_dt_prop(node, "reg", &l);
+                        addr += *(u32 *)of_get_flat_dt_prop(node,
+                                                        "reg-offset", &l);
+                        /* clear register offset */
+                        return be32_to_cpu(addr) & ~3;
+                }
+                if ((strncmp(p, "xlnx,xps-uartlite", 17) == 0) ||
+                                (strncmp(p, "xlnx,opb-uartlite", 17) == 0) ||
+                                (strncmp(p, "xlnx,axi-uartlite", 17) == 0)) {
+                        unsigned int *addrp;
+
+                        *(u32 *)data = UARTLITE;
+
+                        addrp = of_get_flat_dt_prop(node, "reg", &l);
+                        return be32_to_cpup(addrp); /* return address */
+                }
+        }
+        return 0;
 }
 
-/* this function is looking for early uartlite console - Microblaze specific */
-int __init early_uart16550_console(void)
+/* this function is looking for early console - Microblaze specific */
+int __init of_early_console(void *version)
 {
-        return of_scan_flat_dt(early_init_dt_scan_serial_full, NULL);
+        return of_scan_flat_dt(early_init_dt_scan_chosen_serial, version);
 }
 #endif