powerpc: gamecube/wii: early debugging using usbgecko

Add support for using the USB Gecko adapter as an early debugging
console on the Nintendo GameCube and Wii video game consoles.
The USB Gecko is a 3rd party memory card interface adapter that provides
a EXI (External Interface) to USB serial converter.

Signed-off-by: Albert Herranz <albert_herranz@yahoo.es>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

diff --git a/arch/powerpc/Kconfig.debug b/arch/powerpc/Kconfig.debug
index 3b10051..11e385b 100644 (file)
--- a/arch/powerpc/Kconfig.debug
+++ b/arch/powerpc/Kconfig.debug
@@ -254,6 +254,14 @@ config PPC_EARLY_DEBUG_CPM
          using a CPM-based serial port.  This assumes that the bootwrapper
          has run, and set up the CPM in a particular way.
 
+config PPC_EARLY_DEBUG_USBGECKO
+       bool "Early debugging through the USB Gecko adapter"
+       depends on GAMECUBE_COMMON
+       select USBGECKO_UDBG
+       help
+         Select this to enable early debugging for Nintendo GameCube/Wii
+         consoles via an external USB Gecko adapter.
+
 endchoice
 
 config PPC_EARLY_DEBUG_44x_PHYSLOW

diff --git a/arch/powerpc/include/asm/udbg.h b/arch/powerpc/include/asm/udbg.h
index cd21e5e..11ae699 100644 (file)
--- a/arch/powerpc/include/asm/udbg.h
+++ b/arch/powerpc/include/asm/udbg.h
@@ -51,6 +51,7 @@ extern void __init udbg_init_btext(void);
 extern void __init udbg_init_44x_as1(void);
 extern void __init udbg_init_40x_realmode(void);
 extern void __init udbg_init_cpm(void);
+extern void __init udbg_init_usbgecko(void);
 
 #endif /* __KERNEL__ */
 #endif /* _ASM_POWERPC_UDBG_H */

diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S
index 829c3fe..e025e89 100644 (file)
--- a/arch/powerpc/kernel/head_32.S
+++ b/arch/powerpc/kernel/head_32.S
@@ -164,6 +164,9 @@ __after_mmu_off:
 #ifdef CONFIG_PPC_EARLY_DEBUG_CPM
        bl      setup_cpm_bat
 #endif
+#ifdef CONFIG_PPC_EARLY_DEBUG_USBGECKO
+       bl      setup_usbgecko_bat
+#endif
 
 /*
  * Call setup_cpu for CPU 0 and initialize 6xx Idle
@@ -1203,6 +1206,28 @@ setup_cpm_bat:
        blr
 #endif
 
+#ifdef CONFIG_PPC_EARLY_DEBUG_USBGECKO
+setup_usbgecko_bat:
+       /* prepare a BAT for early io */
+#if defined(CONFIG_GAMECUBE)
+       lis     r8, 0x0c00
+#elif defined(CONFIG_WII)
+       lis     r8, 0x0d00
+#else
+#error Invalid platform for USB Gecko based early debugging.
+#endif
+       /*
+        * The virtual address used must match the virtual address
+        * associated to the fixmap entry FIX_EARLY_DEBUG_BASE.
+        */
+       lis     r11, 0xfffe     /* top 128K */
+       ori     r8, r8, 0x002a  /* uncached, guarded ,rw */
+       ori     r11, r11, 0x2   /* 128K, Vs=1, Vp=0 */
+       mtspr   SPRN_DBAT1L, r8
+       mtspr   SPRN_DBAT1U, r11
+       blr
+#endif
+
 #ifdef CONFIG_8260
 /* Jump into the system reset for the rom.
  * We first disable the MMU, and then jump to the ROM reset address.

diff --git a/arch/powerpc/kernel/udbg.c b/arch/powerpc/kernel/udbg.c
index fc9af47..e39cad8 100644 (file)
--- a/arch/powerpc/kernel/udbg.c
+++ b/arch/powerpc/kernel/udbg.c
@@ -60,6 +60,8 @@ void __init udbg_early_init(void)
        udbg_init_40x_realmode();
 #elif defined(CONFIG_PPC_EARLY_DEBUG_CPM)
        udbg_init_cpm();
+#elif defined(CONFIG_PPC_EARLY_DEBUG_USBGECKO)
+       udbg_init_usbgecko();
 #endif
 
 #ifdef CONFIG_PPC_EARLY_DEBUG

diff --git a/arch/powerpc/platforms/embedded6xx/usbgecko_udbg.c b/arch/powerpc/platforms/embedded6xx/usbgecko_udbg.c
index ba4c7cc..edc956c 100644 (file)
--- a/arch/powerpc/platforms/embedded6xx/usbgecko_udbg.c
+++ b/arch/powerpc/platforms/embedded6xx/usbgecko_udbg.c
@@ -17,6 +17,7 @@
 #include <asm/io.h>
 #include <asm/prom.h>
 #include <asm/udbg.h>
+#include <asm/fixmap.h>
 
 #include "usbgecko_udbg.h"
 
@@ -270,3 +271,58 @@ done:
                of_node_put(np);
        return;
 }
+
+#ifdef CONFIG_PPC_EARLY_DEBUG_USBGECKO
+
+static phys_addr_t __init ug_early_grab_io_addr(void)
+{
+#if defined(CONFIG_GAMECUBE)
+       return 0x0c000000;
+#elif defined(CONFIG_WII)
+       return 0x0d000000;
+#else
+#error Invalid platform for USB Gecko based early debugging.
+#endif
+}
+
+/*
+ * USB Gecko early debug support initialization for udbg.
+ */
+void __init udbg_init_usbgecko(void)
+{
+       void __iomem *early_debug_area;
+       void __iomem *exi_io_base;
+
+       /*
+        * At this point we have a BAT already setup that enables I/O
+        * to the EXI hardware.
+        *
+        * The BAT uses a virtual address range reserved at the fixmap.
+        * This must match the virtual address configured in
+        * head_32.S:setup_usbgecko_bat().
+        */
+       early_debug_area = (void __iomem *)__fix_to_virt(FIX_EARLY_DEBUG_BASE);
+       exi_io_base = early_debug_area + 0x00006800;
+
+       /* try to detect a USB Gecko */
+       if (!ug_udbg_probe(exi_io_base))
+               return;
+
+       /* we found a USB Gecko, load udbg hooks */
+       udbg_putc = ug_udbg_putc;
+       udbg_getc = ug_udbg_getc;
+       udbg_getc_poll = ug_udbg_getc_poll;
+
+       /*
+        * Prepare again the same BAT for MMU_init.
+        * This allows udbg I/O to continue working after the MMU is
+        * turned on for real.
+        * It is safe to continue using the same virtual address as it is
+        * a reserved fixmap area.
+        */
+       setbat(1, (unsigned long)early_debug_area,
+              ug_early_grab_io_addr(), 128*1024, PAGE_KERNEL_NCG);
+}
+
+#endif /* CONFIG_PPC_EARLY_DEBUG_USBGECKO */
+

diff --git a/arch/powerpc/platforms/embedded6xx/usbgecko_udbg.h b/arch/powerpc/platforms/embedded6xx/usbgecko_udbg.h
index 3929de3..bb6cde4 100644 (file)
--- a/arch/powerpc/platforms/embedded6xx/usbgecko_udbg.h
+++ b/arch/powerpc/platforms/embedded6xx/usbgecko_udbg.h
@@ -27,4 +27,6 @@ static inline void __init ug_udbg_init(void)
 
 #endif /* CONFIG_USBGECKO_UDBG */
 
+void __init udbg_init_usbgecko(void);
+
 #endif /* __USBGECKO_UDBG_H */