[PATCH] ppc64: Add new "Maple" platform support

This adds support for the Maple 970FX Eval Board.  It adds the basic
arch support.  For the Maple to be fully functional, it needs a couple
more patches to be applied for IDE and Ethernet that are currently
pending with the respective maintainers of those subsystems.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/ppc64/Kconfig

@@ -80,6 +80,16 @@ config PPC_PMAC
 	select ADB_PMU
 	select U3_DART
 
+config PPC_MAPLE
+	depends on PPC_MULTIPLATFORM
+	bool "  Maple 970FX Evaluation Board"
+	select U3_DART
+	select MPIC_BROKEN_U3
+	default n
+	help
+          This option enables support for the Maple 970FX Evaluation Board.
+	  For more informations, refer to http://www.970eval.com
+
 config PPC
 	bool
 	default y
@@ -120,6 +130,11 @@ config U3_DART
 	depends on PPC_MULTIPLATFORM
 	default n
 
+config MPIC_BROKEN_U3
+	bool
+	depends on PPC_MAPLE
+	default y
+
 config PPC_PMAC64
 	bool
 	depends on PPC_PMAC

arch/ppc64/Makefile

@@ -55,11 +55,13 @@ drivers-$(CONFIG_OPROFILE)	+= arch/ppc64/oprofile/
 boot := arch/ppc64/boot
 
 boottarget-$(CONFIG_PPC_PSERIES) := zImage zImage.initrd
+boottarget-$(CONFIG_PPC_MAPLE) := zImage zImage.initrd
 boottarget-$(CONFIG_PPC_ISERIES) := vmlinux.sminitrd vmlinux.initrd vmlinux.sm
 $(boottarget-y): vmlinux
 	$(Q)$(MAKE) $(build)=$(boot) $(boot)/$@
 
 bootimage-$(CONFIG_PPC_PSERIES) := zImage
+bootimage-$(CONFIG_PPC_MAPLE) := zImage
 bootimage-$(CONFIG_PPC_ISERIES) := vmlinux
 BOOTIMAGE := $(bootimage-y)
 install: vmlinux

arch/ppc64/kernel/Makefile

@@ -50,12 +50,15 @@ obj-$(CONFIG_IBMVIO)		+= vio.o
 obj-$(CONFIG_PPC_PMAC)		+= pmac_setup.o pmac_feature.o pmac_pci.o \
 				   pmac_time.o pmac_nvram.o pmac_low_i2c.o
 
+obj-$(CONFIG_PPC_MAPLE)		+= maple_setup.o maple_pci.o maple_time.o
+
 obj-$(CONFIG_U3_DART)		+= u3_iommu.o
 
 ifdef CONFIG_SMP
 obj-$(CONFIG_PPC_PMAC)		+= pmac_smp.o smp-tbsync.o
 obj-$(CONFIG_PPC_ISERIES)	+= iSeries_smp.o
 obj-$(CONFIG_PPC_PSERIES)	+= pSeries_smp.o
+obj-$(CONFIG_PPC_MAPLE)		+= smp-tbsync.o
 endif
 
 obj-$(CONFIG_ALTIVEC)		+= vecemu.o vector.o

arch/ppc64/kernel/idle.c

@@ -22,6 +22,7 @@
 #include <linux/cpu.h>
 #include <linux/module.h>
 #include <linux/sysctl.h>
+#include <linux/smp.h>
 
 #include <asm/system.h>
 #include <asm/processor.h>
@@ -363,12 +364,13 @@ int idle_setup(void)
 		}
 	}
 #endif /* CONFIG_PPC_PSERIES */
-#ifdef CONFIG_PPC_PMAC
-	if (systemcfg->platform == PLATFORM_POWERMAC) {
+#ifndef CONFIG_PPC_ISERIES
+	if (systemcfg->platform == PLATFORM_POWERMAC ||
+	    systemcfg->platform == PLATFORM_MAPLE) {
 		printk(KERN_INFO "Using native/NAP idle loop\n");
 		idle_loop = native_idle;
 	}
-#endif /* CONFIG_PPC_PMAC */
+#endif /* CONFIG_PPC_ISERIES */
 
 	return 1;
 }

arch/ppc64/kernel/maple_setup.c

+/*
+ *  arch/ppc64/kernel/maple_setup.c
+ *
+ *  (c) Copyright 2004 Benjamin Herrenschmidt (benh@kernel.crashing.org),
+ *                     IBM Corp. 
+ *
+ *  This program is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU General Public License
+ *  as published by the Free Software Foundation; either version
+ *  2 of the License, or (at your option) any later version.
+ *
+ */
+
+#define DEBUG
+
+#include <linux/config.h>
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/stddef.h>
+#include <linux/unistd.h>
+#include <linux/ptrace.h>
+#include <linux/slab.h>
+#include <linux/user.h>
+#include <linux/a.out.h>
+#include <linux/tty.h>
+#include <linux/string.h>
+#include <linux/delay.h>
+#include <linux/ioport.h>
+#include <linux/major.h>
+#include <linux/initrd.h>
+#include <linux/vt_kern.h>
+#include <linux/console.h>
+#include <linux/ide.h>
+#include <linux/pci.h>
+#include <linux/adb.h>
+#include <linux/cuda.h>
+#include <linux/pmu.h>
+#include <linux/irq.h>
+#include <linux/seq_file.h>
+#include <linux/root_dev.h>
+#include <linux/serial.h>
+#include <linux/smp.h>
+
+#include <asm/processor.h>
+#include <asm/sections.h>
+#include <asm/prom.h>
+#include <asm/system.h>
+#include <asm/pgtable.h>
+#include <asm/bitops.h>
+#include <asm/io.h>
+#include <asm/pci-bridge.h>
+#include <asm/iommu.h>
+#include <asm/machdep.h>
+#include <asm/dma.h>
+#include <asm/cputable.h>
+#include <asm/time.h>
+#include <asm/of_device.h>
+#include <asm/lmb.h>
+
+#include "mpic.h"
+
+#ifdef DEBUG
+#define DBG(fmt...) udbg_printf(fmt)
+#else
+#define DBG(fmt...)
+#endif
+
+extern int maple_set_rtc_time(struct rtc_time *tm);
+extern void maple_get_rtc_time(struct rtc_time *tm);
+extern void maple_get_boot_time(struct rtc_time *tm);
+extern void maple_calibrate_decr(void);
+extern void maple_pci_init(void);
+extern void maple_pcibios_fixup(void);
+extern int maple_pci_get_legacy_ide_irq(struct pci_dev *dev, int channel);
+extern void generic_find_legacy_serial_ports(unsigned int *default_speed);
+
+
+static void maple_restart(char *cmd)
+{
+}
+
+static void maple_power_off(void)
+{
+}
+
+static void maple_halt(void)
+{
+}
+
+#ifdef CONFIG_SMP
+struct smp_ops_t maple_smp_ops = {
+	.probe		= smp_mpic_probe,
+	.message_pass	= smp_mpic_message_pass,
+	.kick_cpu	= smp_generic_kick_cpu,
+	.setup_cpu	= smp_mpic_setup_cpu,
+	.give_timebase	= smp_generic_give_timebase,
+	.take_timebase	= smp_generic_take_timebase,
+};
+#endif /* CONFIG_SMP */
+
+void __init maple_setup_arch(void)
+{
+	/* init to some ~sane value until calibrate_delay() runs */
+	loops_per_jiffy = 50000000;
+
+	/* Setup SMP callback */
+#ifdef CONFIG_SMP
+	smp_ops = &maple_smp_ops;
+#endif
+	/* Setup the PCI DMA to "direct" by default. May be overriden
+	 * by iommu later on
+	 */
+	pci_dma_init_direct();
+
+	/* Lookup PCI hosts */
+       	maple_pci_init();
+
+#ifdef CONFIG_DUMMY_CONSOLE
+	conswitchp = &dummy_con;
+#endif
+}
+
+/* 
+ * Early initialization.
+ */
+static void __init maple_init_early(void)
+{
+	unsigned int default_speed;
+
+	DBG(" -> maple_init_early\n");
+
+	/* Initialize hash table, from now on, we can take hash faults
+	 * and call ioremap
+	 */
+	hpte_init_native();
+
+	/* Find the serial port */
+       	generic_find_legacy_serial_ports(&default_speed);
+
+	DBG("naca->serialPortAddr: %lx\n", (long)naca->serialPortAddr);
+
+	if (naca->serialPortAddr) {
+		void *comport;
+		/* Map the uart for udbg. */
+		comport = (void *)__ioremap(naca->serialPortAddr, 16, _PAGE_NO_CACHE);
+		udbg_init_uart(comport, default_speed);
+
+		ppc_md.udbg_putc = udbg_putc;
+		ppc_md.udbg_getc = udbg_getc;
+		ppc_md.udbg_getc_poll = udbg_getc_poll;
+		DBG("Hello World !\n");
+	}
+
+	/* Setup interrupt mapping options */
+	naca->interrupt_controller = IC_OPEN_PIC;
+
+	DBG(" <- maple_init_early\n");
+}
+
+
+static __init void maple_init_IRQ(void)
+{
+	struct device_node *root;
+	unsigned int *opprop;
+	unsigned long opic_addr;
+	struct mpic *mpic;
+	unsigned char senses[128];
+	int n;
+
+	DBG(" -> maple_init_IRQ\n");
+
+	/* XXX: Non standard, replace that with a proper openpic/mpic node
+	 * in the device-tree. Find the Open PIC if present */
+	root = of_find_node_by_path("/");
+	opprop = (unsigned int *) get_property(root,
+				"platform-open-pic", NULL);
+	if (opprop == 0)
+		panic("OpenPIC not found !\n");
+
+	n = prom_n_addr_cells(root);
+	for (opic_addr = 0; n > 0; --n)
+		opic_addr = (opic_addr << 32) + *opprop++;
+	of_node_put(root);
+
+	/* Obtain sense values from device-tree */
+	prom_get_irq_senses(senses, 0, 128);
+
+	mpic = mpic_alloc(opic_addr,
+			  MPIC_PRIMARY | MPIC_BIG_ENDIAN |
+			  MPIC_BROKEN_U3 | MPIC_WANTS_RESET,
+			  0, 0, 128, 128, senses, 128, "U3-MPIC");
+	BUG_ON(mpic == NULL);
+	mpic_init(mpic);
+
+	DBG(" <- maple_init_IRQ\n");
+}
+
+static void __init maple_progress(char *s, unsigned short hex)
+{
+	printk("*** %04x : %s\n", hex, s ? s : "");
+}
+
+
+/*
+ * Called very early, MMU is off, device-tree isn't unflattened
+ */
+static int __init maple_probe(int platform)
+{
+	if (platform != PLATFORM_MAPLE)
+		return 0;
+	/*
+	 * On U3, the DART (iommu) must be allocated now since it
+	 * has an impact on htab_initialize (due to the large page it
+	 * occupies having to be broken up so the DART itself is not
+	 * part of the cacheable linar mapping
+	 */
+	alloc_u3_dart_table();
+
+	return 1;
+}
+
+struct machdep_calls __initdata maple_md = {
+	.probe			= maple_probe,
+	.setup_arch		= maple_setup_arch,
+	.init_early		= maple_init_early,
+	.init_IRQ		= maple_init_IRQ,
+	.get_irq		= mpic_get_irq,
+	.pcibios_fixup		= maple_pcibios_fixup,
+#if 0
+	.pci_get_legacy_ide_irq	= maple_pci_get_legacy_ide_irq,
+#endif
+	.restart		= maple_restart,
+	.power_off		= maple_power_off,
+	.halt			= maple_halt,
+       	.get_boot_time		= maple_get_boot_time,
+       	.set_rtc_time		= maple_set_rtc_time,
+       	.get_rtc_time		= maple_get_rtc_time,
+      	.calibrate_decr		= maple_calibrate_decr,
+	.progress		= maple_progress,
+};

arch/ppc64/kernel/maple_time.c

+/*
+ *  arch/ppc64/kernel/maple_time.c
+ *
+ *  (c) Copyright 2004 Benjamin Herrenschmidt (benh@kernel.crashing.org),
+ *                     IBM Corp. 
+ *
+ *  This program is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU General Public License
+ *  as published by the Free Software Foundation; either version
+ *  2 of the License, or (at your option) any later version.
+ *
+ */
+
+#undef DEBUG
+
+#include <linux/config.h>
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/param.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/init.h>
+#include <linux/time.h>
+#include <linux/adb.h>
+#include <linux/pmu.h>
+#include <linux/interrupt.h>
+#include <linux/mc146818rtc.h>
+#include <linux/bcd.h>
+
+#include <asm/sections.h>
+#include <asm/prom.h>
+#include <asm/system.h>
+#include <asm/io.h>
+#include <asm/pgtable.h>
+#include <asm/machdep.h>
+#include <asm/time.h>
+
+#ifdef DEBUG
+#define DBG(x...) printk(x)
+#else
+#define DBG(x...)
+#endif
+
+extern void setup_default_decr(void);
+extern void GregorianDay(struct rtc_time * tm);
+
+extern unsigned long ppc_tb_freq;
+extern unsigned long ppc_proc_freq;
+static int maple_rtc_addr;
+
+static int maple_clock_read(int addr)
+{
+	outb_p(addr, maple_rtc_addr);
+	return inb_p(maple_rtc_addr+1);
+}
+
+static void maple_clock_write(unsigned long val, int addr)
+{
+	outb_p(addr, maple_rtc_addr);
+	outb_p(val, maple_rtc_addr+1);
+}
+
+void maple_get_rtc_time(struct rtc_time *tm)
+{
+	int uip, i;
+
+	/* The Linux interpretation of the CMOS clock register contents:
+	 * When the Update-In-Progress (UIP) flag goes from 1 to 0, the
+	 * RTC registers show the second which has precisely just started.
+	 * Let's hope other operating systems interpret the RTC the same way.
+	 */
+
+	/* Since the UIP flag is set for about 2.2 ms and the clock
+	 * is typically written with a precision of 1 jiffy, trying
+	 * to obtain a precision better than a few milliseconds is
+	 * an illusion. Only consistency is interesting, this also
+	 * allows to use the routine for /dev/rtc without a potential
+	 * 1 second kernel busy loop triggered by any reader of /dev/rtc.
+	 */
+
+	for (i = 0; i<1000000; i++) {
+		uip = maple_clock_read(RTC_FREQ_SELECT);
+		tm->tm_sec = maple_clock_read(RTC_SECONDS);
+		tm->tm_min = maple_clock_read(RTC_MINUTES);
+		tm->tm_hour = maple_clock_read(RTC_HOURS);
+		tm->tm_mday = maple_clock_read(RTC_DAY_OF_MONTH);
+		tm->tm_mon = maple_clock_read(RTC_MONTH);
+		tm->tm_year = maple_clock_read(RTC_YEAR);
+		uip |= maple_clock_read(RTC_FREQ_SELECT);
+		if ((uip & RTC_UIP)==0)
+			break;
+	}
+
+	if (!(maple_clock_read(RTC_CONTROL) & RTC_DM_BINARY)
+	    || RTC_ALWAYS_BCD) {
+		BCD_TO_BIN(tm->tm_sec);
+		BCD_TO_BIN(tm->tm_min);
+		BCD_TO_BIN(tm->tm_hour);
+		BCD_TO_BIN(tm->tm_mday);
+		BCD_TO_BIN(tm->tm_mon);
+		BCD_TO_BIN(tm->tm_year);
+	  }
+	if ((tm->tm_year + 1900) < 1970)
+		tm->tm_year += 100;
+
+	GregorianDay(tm);
+}
+
+int maple_set_rtc_time(struct rtc_time *tm)
+{
+	unsigned char save_control, save_freq_select;
+	int sec, min, hour, mon, mday, year;
+
+	spin_lock(&rtc_lock);
+
+	save_control = maple_clock_read(RTC_CONTROL); /* tell the clock it's being set */
+
+	maple_clock_write((save_control|RTC_SET), RTC_CONTROL);
+
+	save_freq_select = maple_clock_read(RTC_FREQ_SELECT); /* stop and reset prescaler */
+
+	maple_clock_write((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT);
+
+	sec = tm->tm_sec;
+	min = tm->tm_min;
+	hour = tm->tm_hour;
+	mon = tm->tm_mon;
+	mday = tm->tm_mday;
+	year = tm->tm_year;
+
+	if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
+		BIN_TO_BCD(sec);
+		BIN_TO_BCD(min);
+		BIN_TO_BCD(hour);
+		BIN_TO_BCD(mon);
+		BIN_TO_BCD(mday);
+		BIN_TO_BCD(year);
+	}
+	maple_clock_write(sec, RTC_SECONDS);
+	maple_clock_write(min, RTC_MINUTES);
+	maple_clock_write(hour, RTC_HOURS);
+	maple_clock_write(mon, RTC_MONTH);
+	maple_clock_write(mday, RTC_DAY_OF_MONTH);
+	maple_clock_write(year, RTC_YEAR);
+
+	/* The following flags have to be released exactly in this order,
+	 * otherwise the DS12887 (popular MC146818A clone with integrated
+	 * battery and quartz) will not reset the oscillator and will not
+	 * update precisely 500 ms later. You won't find this mentioned in
+	 * the Dallas Semiconductor data sheets, but who believes data
+	 * sheets anyway ...                           -- Markus Kuhn
+	 */
+	maple_clock_write(save_control, RTC_CONTROL);
+	maple_clock_write(save_freq_select, RTC_FREQ_SELECT);
+
+	spin_unlock(&rtc_lock);
+
+	return 0;
+}
+
+void __init maple_get_boot_time(struct rtc_time *tm)
+{
+	struct device_node *rtcs;
+
+	rtcs = find_compatible_devices("rtc", "pnpPNP,b00");
+	if (rtcs && rtcs->addrs) {
+		maple_rtc_addr = rtcs->addrs[0].address;
+		printk(KERN_INFO "Maple: Found RTC at 0x%x\n", maple_rtc_addr);
+	} else {
+		maple_rtc_addr = RTC_PORT(0); /* legacy address */
+		printk(KERN_INFO "Maple: No device node for RTC, assuming "
+		       "legacy address (0x%x)\n", maple_rtc_addr);
+	}
+	
+	maple_get_rtc_time(tm);
+}
+
+/* XXX FIXME: Some sane defaults: 125 MHz timebase, 1GHz processor */
+#define DEFAULT_TB_FREQ		125000000UL
+#define DEFAULT_PROC_FREQ	(DEFAULT_TB_FREQ * 8)
+
+void __init maple_calibrate_decr(void)
+{
+	struct device_node *cpu;
+	struct div_result divres;
+	unsigned int *fp = NULL;
+
+	/*
+	 * The cpu node should have a timebase-frequency property
+	 * to tell us the rate at which the decrementer counts.
+	 */
+	cpu = of_find_node_by_type(NULL, "cpu");
+
+	ppc_tb_freq = DEFAULT_TB_FREQ;
+	if (cpu != 0)
+		fp = (unsigned int *)get_property(cpu, "timebase-frequency", NULL);
+	if (fp != NULL)
+		ppc_tb_freq = *fp;
+	else
+		printk(KERN_ERR "WARNING: Estimating decrementer frequency (not found)\n");
+	fp = NULL;
+	ppc_proc_freq = DEFAULT_PROC_FREQ;
+	if (cpu != 0)
+		fp = (unsigned int *)get_property(cpu, "clock-frequency", NULL);
+	if (fp != NULL)
+		ppc_proc_freq = *fp;
+	else
+		printk(KERN_ERR "WARNING: Estimating processor frequency (not found)\n");
+
+	of_node_put(cpu);
+
+	printk(KERN_INFO "time_init: decrementer frequency = %lu.%.6lu MHz\n",
+	       ppc_tb_freq/1000000, ppc_tb_freq%1000000);
+	printk(KERN_INFO "time_init: processor frequency   = %lu.%.6lu MHz\n",
+	       ppc_proc_freq/1000000, ppc_proc_freq%1000000);
+
+	tb_ticks_per_jiffy = ppc_tb_freq / HZ;
+	tb_ticks_per_sec = tb_ticks_per_jiffy * HZ;
+	tb_ticks_per_usec = ppc_tb_freq / 1000000;
+	tb_to_us = mulhwu_scale_factor(ppc_tb_freq, 1000000);
+	div128_by_32(1024*1024, 0, tb_ticks_per_sec, &divres);
+	tb_to_xs = divres.result_low;
+
+	setup_default_decr();
+}

arch/ppc64/kernel/misc.S

@@ -591,7 +591,7 @@ _GLOBAL(do_cpu_ftr_fixups)
 	isync
 	b	1b
 
-#ifdef CONFIG_PPC_PMAC
+#if defined(CONFIG_PPC_PMAC) || defined(CONFIG_PPC_MAPLE)
 /*
  * Do an IO access in real mode
  */
@@ -653,7 +653,7 @@ _GLOBAL(real_writeb)
 	sync
 	isync
 	blr
-#endif /* CONFIG_PPC_PMAC */
+#endif /* defined(CONFIG_PPC_PMAC) || defined(CONFIG_PPC_MAPLE) */
 
 /*
  * Create a kernel thread

arch/ppc64/kernel/prom_init.c

@@ -1132,6 +1132,8 @@ static int __init prom_find_machine_type(void)
 			if (strstr(p, RELOC("Power Macintosh")) ||
 			    strstr(p, RELOC("MacRISC4")))
 				return PLATFORM_POWERMAC;
+			if (strstr(p, RELOC("Momentum,Maple")))
+				return PLATFORM_MAPLE;
 			i += sl + 1;
 		}
 	}

arch/ppc64/kernel/setup.c

@@ -75,11 +75,14 @@ extern void udbg_init_debug_lpar(void);
 extern void udbg_init_pmac_realmode(void);
 /* That's RTAS panel debug */
 extern void call_rtas_display_status_delay(unsigned char c);
+/* Here's maple real mode debug */
+extern void udbg_init_maple_realmode(void);
 
 #define EARLY_DEBUG_INIT() do {} while(0)
 
 #if 0
 #define EARLY_DEBUG_INIT() udbg_init_debug_lpar()
+#define EARLY_DEBUG_INIT() udbg_init_maple_realmode()
 #define EARLY_DEBUG_INIT() udbg_init_pmac_realmode()
 #define EARLY_DEBUG_INIT()						\
 	do { ppc_md.udbg_putc = call_rtas_display_status_delay; } while(0)
@@ -326,6 +329,7 @@ static void __init setup_cpu_maps(void)
 
 extern struct machdep_calls pSeries_md;
 extern struct machdep_calls pmac_md;
+extern struct machdep_calls maple_md;
 
 /* Ultimately, stuff them in an elf section like initcalls... */
 static struct machdep_calls __initdata *machines[] = {
@@ -335,6 +339,9 @@ static struct machdep_calls __initdata *machines[] = {
 #ifdef CONFIG_PPC_PMAC
 	&pmac_md,
 #endif /* CONFIG_PPC_PMAC */
+#ifdef CONFIG_PPC_MAPLE
+	&maple_md,
+#endif /* CONFIG_PPC_MAPLE */
 	NULL
 };
 
@@ -633,6 +640,7 @@ void __init setup_system(void)
 	printk("naca->debug_switch            = 0x%lx\n", naca->debug_switch);
 	printk("naca->interrupt_controller    = 0x%ld\n", naca->interrupt_controller);
 	printk("systemcfg                     = 0x%p\n", systemcfg);
+	printk("systemcfg->platform           = 0x%x\n", systemcfg->platform);
 	printk("systemcfg->processorCount     = 0x%lx\n", systemcfg->processorCount);
 	printk("systemcfg->physicalMemorySize = 0x%lx\n", systemcfg->physicalMemorySize);
 	printk("systemcfg->dCacheL1LineSize   = 0x%x\n", systemcfg->dCacheL1LineSize);

arch/ppc64/kernel/udbg.c

@@ -20,6 +20,9 @@
 #include <asm/prom.h>
 #include <asm/pmac_feature.h>
 
+extern u8 real_readb(volatile u8 *addr);
+extern void real_writeb(u8 data, volatile u8 *addr);
+
 struct NS16550 {
 	/* this struct must be packed */
 	unsigned char rbr;  /* 0 */
@@ -148,9 +151,6 @@ void udbg_init_scc(struct device_node *np)
 #endif /* CONFIG_PPC_PMAC */
 
 #if CONFIG_PPC_PMAC
-extern u8 real_readb(volatile u8 *addr);
-extern void real_writeb(u8 data, volatile u8 *addr);
-
 static void udbg_real_putc(unsigned char c)
 {
 	while ((real_readb(sccc) & SCC_TXRDY) == 0)
@@ -171,6 +171,32 @@ void udbg_init_pmac_realmode(void)
 }
 #endif /* CONFIG_PPC_PMAC */
 
+#ifdef CONFIG_PPC_MAPLE
+void udbg_maple_real_putc(unsigned char c)
+{
+	if (udbg_comport) {
+		while ((real_readb(&udbg_comport->lsr) & LSR_THRE) == 0)
+			/* wait for idle */;
+		real_writeb(c, &udbg_comport->thr); eieio();
+		if (c == '\n') {
+			/* Also put a CR.  This is for convenience. */
+			while ((real_readb(&udbg_comport->lsr) & LSR_THRE) == 0)
+				/* wait for idle */;
+			real_writeb('\r', &udbg_comport->thr); eieio();
+		}
+	}
+}
+
+void udbg_init_maple_realmode(void)
+{
+	udbg_comport = (volatile struct NS16550 *)0xf40003f8;
+
+	ppc_md.udbg_putc = udbg_maple_real_putc;
+	ppc_md.udbg_getc = NULL;
+	ppc_md.udbg_getc_poll = NULL;
+}
+#endif /* CONFIG_PPC_MAPLE */
+
 void udbg_putc(unsigned char c)
 {
 	if (udbg_comport) {

include/asm-ppc64/processor.h

@@ -389,6 +389,7 @@
 #define PLATFORM_ISERIES_LPAR 0x0201
 #define PLATFORM_LPAR         0x0001
 #define PLATFORM_POWERMAC     0x0400
+#define PLATFORM_MAPLE        0x0500
 
 /* Compatibility with drivers coming from PPC32 world */
 #define _machine	(systemcfg->platform)