powerpc: Merge enough to start building in arch/powerpc.

This creates the directory structure under arch/powerpc and a bunch
of Kconfig files.  It does a first-cut merge of arch/powerpc/mm,
arch/powerpc/lib and arch/powerpc/platforms/powermac.  This is enough
to build a 32-bit powermac kernel with ARCH=powerpc.

For now we are getting some unmerged files from arch/ppc/kernel and
arch/ppc/syslib, or arch/ppc64/kernel.  This makes some minor changes
to files in those directories and files outside arch/powerpc.

The boot directory is still not merged.  That's going to be interesting.

Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 728 insertions, 0 deletions

diff --git a/arch/powerpc/platforms/powermac/pmac_cpufreq.c b/arch/powerpc/platforms/powermac/pmac_cpufreq.c
new file mode 100644
index 000000000000..6d32d99402be
--- /dev/null
+++ b/arch/powerpc/platforms/powermac/pmac_cpufreq.c
@@ -0,0 +1,728 @@
+/*
+ *  arch/ppc/platforms/pmac_cpufreq.c
+ *
+ *  Copyright (C) 2002 - 2005 Benjamin Herrenschmidt <benh@kernel.crashing.org>
+ *  Copyright (C) 2004        John Steele Scott <toojays@toojays.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * TODO: Need a big cleanup here. Basically, we need to have different
+ * cpufreq_driver structures for the different type of HW instead of the
+ * current mess. We also need to better deal with the detection of the
+ * type of machine.
+ *
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/sched.h>
+#include <linux/adb.h>
+#include <linux/pmu.h>
+#include <linux/slab.h>
+#include <linux/cpufreq.h>
+#include <linux/init.h>
+#include <linux/sysdev.h>
+#include <linux/i2c.h>
+#include <linux/hardirq.h>
+#include <asm/prom.h>
+#include <asm/machdep.h>
+#include <asm/irq.h>
+#include <asm/pmac_feature.h>
+#include <asm/mmu_context.h>
+#include <asm/sections.h>
+#include <asm/cputable.h>
+#include <asm/time.h>
+#include <asm/system.h>
+#include <asm/mpic.h>
+#include <asm/keylargo.h>
+
+/* WARNING !!! This will cause calibrate_delay() to be called,
+ * but this is an __init function ! So you MUST go edit
+ * init/main.c to make it non-init before enabling DEBUG_FREQ
+ */
+#undef DEBUG_FREQ
+
+/*
+ * There is a problem with the core cpufreq code on SMP kernels,
+ * it won't recalculate the Bogomips properly
+ */
+#ifdef CONFIG_SMP
+#warning "WARNING, CPUFREQ not recommended on SMP kernels"
+#endif
+
+extern void low_choose_7447a_dfs(int dfs);
+extern void low_choose_750fx_pll(int pll);
+extern void low_sleep_handler(void);
+
+/*
+ * Currently, PowerMac cpufreq supports only high & low frequencies
+ * that are set by the firmware
+ */
+static unsigned int low_freq;
+static unsigned int hi_freq;
+static unsigned int cur_freq;
+static unsigned int sleep_freq;
+
+/*
+ * Different models uses different mecanisms to switch the frequency
+ */
+static int (*set_speed_proc)(int low_speed);
+static unsigned int (*get_speed_proc)(void);
+
+/*
+ * Some definitions used by the various speedprocs
+ */
+static u32 voltage_gpio;
+static u32 frequency_gpio;
+static u32 slew_done_gpio;
+static int no_schedule;
+static int has_cpu_l2lve;
+static int is_pmu_based;
+
+/* There are only two frequency states for each processor. Values
+ * are in kHz for the time being.
+ */
+#define CPUFREQ_HIGH                  0
+#define CPUFREQ_LOW                   1
+
+static struct cpufreq_frequency_table pmac_cpu_freqs[] = {
+	{CPUFREQ_HIGH, 		0},
+	{CPUFREQ_LOW,		0},
+	{0,			CPUFREQ_TABLE_END},
+};
+
+static struct freq_attr* pmac_cpu_freqs_attr[] = {
+	&cpufreq_freq_attr_scaling_available_freqs,
+	NULL,
+};
+
+static inline void local_delay(unsigned long ms)
+{
+	if (no_schedule)
+		mdelay(ms);
+	else
+		msleep(ms);
+}
+
+static inline void wakeup_decrementer(void)
+{
+	set_dec(tb_ticks_per_jiffy);
+	/* No currently-supported powerbook has a 601,
+	 * so use get_tbl, not native
+	 */
+	last_jiffy_stamp(0) = tb_last_stamp = get_tbl();
+}
+
+#ifdef DEBUG_FREQ
+static inline void debug_calc_bogomips(void)
+{
+	/* This will cause a recalc of bogomips and display the
+	 * result. We backup/restore the value to avoid affecting the
+	 * core cpufreq framework's own calculation.
+	 */
+	extern void calibrate_delay(void);
+
+	unsigned long save_lpj = loops_per_jiffy;
+	calibrate_delay();
+	loops_per_jiffy = save_lpj;
+}
+#endif /* DEBUG_FREQ */
+
+/* Switch CPU speed under 750FX CPU control
+ */
+static int cpu_750fx_cpu_speed(int low_speed)
+{
+	u32 hid2;
+
+	if (low_speed == 0) {
+		/* ramping up, set voltage first */
+		pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x05);
+		/* Make sure we sleep for at least 1ms */
+		local_delay(10);
+
+		/* tweak L2 for high voltage */
+		if (has_cpu_l2lve) {
+			hid2 = mfspr(SPRN_HID2);
+			hid2 &= ~0x2000;
+			mtspr(SPRN_HID2, hid2);
+		}
+	}
+#ifdef CONFIG_6xx
+	low_choose_750fx_pll(low_speed);
+#endif
+	if (low_speed == 1) {
+		/* tweak L2 for low voltage */
+		if (has_cpu_l2lve) {
+			hid2 = mfspr(SPRN_HID2);
+			hid2 |= 0x2000;
+			mtspr(SPRN_HID2, hid2);
+		}
+
+		/* ramping down, set voltage last */
+		pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
+		local_delay(10);
+	}
+
+	return 0;
+}
+
+static unsigned int cpu_750fx_get_cpu_speed(void)
+{
+	if (mfspr(SPRN_HID1) & HID1_PS)
+		return low_freq;
+	else
+		return hi_freq;
+}
+
+/* Switch CPU speed using DFS */
+static int dfs_set_cpu_speed(int low_speed)
+{
+	if (low_speed == 0) {
+		/* ramping up, set voltage first */
+		pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x05);
+		/* Make sure we sleep for at least 1ms */
+		local_delay(1);
+	}
+
+	/* set frequency */
+#ifdef CONFIG_6xx
+	low_choose_7447a_dfs(low_speed);
+#endif
+	udelay(100);
+
+	if (low_speed == 1) {
+		/* ramping down, set voltage last */
+		pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
+		local_delay(1);
+	}
+
+	return 0;
+}
+
+static unsigned int dfs_get_cpu_speed(void)
+{
+	if (mfspr(SPRN_HID1) & HID1_DFS)
+		return low_freq;
+	else
+		return hi_freq;
+}
+
+
+/* Switch CPU speed using slewing GPIOs
+ */
+static int gpios_set_cpu_speed(int low_speed)
+{
+	int gpio, timeout = 0;
+
+	/* If ramping up, set voltage first */
+	if (low_speed == 0) {
+		pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x05);
+		/* Delay is way too big but it's ok, we schedule */
+		local_delay(10);
+	}
+
+	/* Set frequency */
+	gpio = 	pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, frequency_gpio, 0);
+	if (low_speed == ((gpio & 0x01) == 0))
+		goto skip;
+
+	pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, frequency_gpio,
+			  low_speed ? 0x04 : 0x05);
+	udelay(200);
+	do {
+		if (++timeout > 100)
+			break;
+		local_delay(1);
+		gpio = pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, slew_done_gpio, 0);
+	} while((gpio & 0x02) == 0);
+ skip:
+	/* If ramping down, set voltage last */
+	if (low_speed == 1) {
+		pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
+		/* Delay is way too big but it's ok, we schedule */
+		local_delay(10);
+	}
+
+#ifdef DEBUG_FREQ
+	debug_calc_bogomips();
+#endif
+
+	return 0;
+}
+
+/* Switch CPU speed under PMU control
+ */
+static int pmu_set_cpu_speed(int low_speed)
+{
+	struct adb_request req;
+	unsigned long save_l2cr;
+	unsigned long save_l3cr;
+	unsigned int pic_prio;
+	unsigned long flags;
+
+	preempt_disable();
+
+#ifdef DEBUG_FREQ
+	printk(KERN_DEBUG "HID1, before: %x\n", mfspr(SPRN_HID1));
+#endif
+	pmu_suspend();
+
+	/* Disable all interrupt sources on openpic */
+ 	pic_prio = mpic_cpu_get_priority();
+	mpic_cpu_set_priority(0xf);
+
+	/* Make sure the decrementer won't interrupt us */
+	asm volatile("mtdec %0" : : "r" (0x7fffffff));
+	/* Make sure any pending DEC interrupt occuring while we did
+	 * the above didn't re-enable the DEC */
+	mb();
+	asm volatile("mtdec %0" : : "r" (0x7fffffff));
+
+	/* We can now disable MSR_EE */
+	local_irq_save(flags);
+
+	/* Giveup the FPU & vec */
+	enable_kernel_fp();
+
+#ifdef CONFIG_ALTIVEC
+	if (cpu_has_feature(CPU_FTR_ALTIVEC))
+		enable_kernel_altivec();
+#endif /* CONFIG_ALTIVEC */
+
+	/* Save & disable L2 and L3 caches */
+	save_l3cr = _get_L3CR();	/* (returns -1 if not available) */
+	save_l2cr = _get_L2CR();	/* (returns -1 if not available) */
+
+	/* Send the new speed command. My assumption is that this command
+	 * will cause PLL_CFG[0..3] to be changed next time CPU goes to sleep
+	 */
+	pmu_request(&req, NULL, 6, PMU_CPU_SPEED, 'W', 'O', 'O', 'F', low_speed);
+	while (!req.complete)
+		pmu_poll();
+
+	/* Prepare the northbridge for the speed transition */
+	pmac_call_feature(PMAC_FTR_SLEEP_STATE,NULL,1,1);
+
+	/* Call low level code to backup CPU state and recover from
+	 * hardware reset
+	 */
+	low_sleep_handler();
+
+	/* Restore the northbridge */
+	pmac_call_feature(PMAC_FTR_SLEEP_STATE,NULL,1,0);
+
+	/* Restore L2 cache */
+	if (save_l2cr != 0xffffffff && (save_l2cr & L2CR_L2E) != 0)
+ 		_set_L2CR(save_l2cr);
+	/* Restore L3 cache */
+	if (save_l3cr != 0xffffffff && (save_l3cr & L3CR_L3E) != 0)
+ 		_set_L3CR(save_l3cr);
+
+	/* Restore userland MMU context */
+	set_context(current->active_mm->context, current->active_mm->pgd);
+
+#ifdef DEBUG_FREQ
+	printk(KERN_DEBUG "HID1, after: %x\n", mfspr(SPRN_HID1));
+#endif
+
+	/* Restore low level PMU operations */
+	pmu_unlock();
+
+	/* Restore decrementer */
+	wakeup_decrementer();
+
+	/* Restore interrupts */
+ 	mpic_cpu_set_priority(pic_prio);
+
+	/* Let interrupts flow again ... */
+	local_irq_restore(flags);
+
+#ifdef DEBUG_FREQ
+	debug_calc_bogomips();
+#endif
+
+	pmu_resume();
+
+	preempt_enable();
+
+	return 0;
+}
+
+static int do_set_cpu_speed(int speed_mode, int notify)
+{
+	struct cpufreq_freqs freqs;
+	unsigned long l3cr;
+	static unsigned long prev_l3cr;
+
+	freqs.old = cur_freq;
+	freqs.new = (speed_mode == CPUFREQ_HIGH) ? hi_freq : low_freq;
+	freqs.cpu = smp_processor_id();
+
+	if (freqs.old == freqs.new)
+		return 0;
+
+	if (notify)
+		cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
+	if (speed_mode == CPUFREQ_LOW &&
+	    cpu_has_feature(CPU_FTR_L3CR)) {
+		l3cr = _get_L3CR();
+		if (l3cr & L3CR_L3E) {
+			prev_l3cr = l3cr;
+			_set_L3CR(0);
+		}
+	}
+	set_speed_proc(speed_mode == CPUFREQ_LOW);
+	if (speed_mode == CPUFREQ_HIGH &&
+	    cpu_has_feature(CPU_FTR_L3CR)) {
+		l3cr = _get_L3CR();
+		if ((prev_l3cr & L3CR_L3E) && l3cr != prev_l3cr)
+			_set_L3CR(prev_l3cr);
+	}
+	if (notify)
+		cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
+	cur_freq = (speed_mode == CPUFREQ_HIGH) ? hi_freq : low_freq;
+
+	return 0;
+}
+
+static unsigned int pmac_cpufreq_get_speed(unsigned int cpu)
+{
+	return cur_freq;
+}
+
+static int pmac_cpufreq_verify(struct cpufreq_policy *policy)
+{
+	return cpufreq_frequency_table_verify(policy, pmac_cpu_freqs);
+}
+
+static int pmac_cpufreq_target(	struct cpufreq_policy *policy,
+					unsigned int target_freq,
+					unsigned int relation)
+{
+	unsigned int    newstate = 0;
+
+	if (cpufreq_frequency_table_target(policy, pmac_cpu_freqs,
+			target_freq, relation, &newstate))
+		return -EINVAL;
+
+	return do_set_cpu_speed(newstate, 1);
+}
+
+unsigned int pmac_get_one_cpufreq(int i)
+{
+	/* Supports only one CPU for now */
+	return (i == 0) ? cur_freq : 0;
+}
+
+static int pmac_cpufreq_cpu_init(struct cpufreq_policy *policy)
+{
+	if (policy->cpu != 0)
+		return -ENODEV;
+
+	policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
+	policy->cpuinfo.transition_latency	= CPUFREQ_ETERNAL;
+	policy->cur = cur_freq;
+
+	cpufreq_frequency_table_get_attr(pmac_cpu_freqs, policy->cpu);
+	return cpufreq_frequency_table_cpuinfo(policy, pmac_cpu_freqs);
+}
+
+static u32 read_gpio(struct device_node *np)
+{
+	u32 *reg = (u32 *)get_property(np, "reg", NULL);
+	u32 offset;
+
+	if (reg == NULL)
+		return 0;
+	/* That works for all keylargos but shall be fixed properly
+	 * some day... The problem is that it seems we can't rely
+	 * on the "reg" property of the GPIO nodes, they are either
+	 * relative to the base of KeyLargo or to the base of the
+	 * GPIO space, and the device-tree doesn't help.
+	 */
+	offset = *reg;
+	if (offset < KEYLARGO_GPIO_LEVELS0)
+		offset += KEYLARGO_GPIO_LEVELS0;
+	return offset;
+}
+
+static int pmac_cpufreq_suspend(struct cpufreq_policy *policy, pm_message_t pmsg)
+{
+	/* Ok, this could be made a bit smarter, but let's be robust for now. We
+	 * always force a speed change to high speed before sleep, to make sure
+	 * we have appropriate voltage and/or bus speed for the wakeup process,
+	 * and to make sure our loops_per_jiffies are "good enough", that is will
+	 * not cause too short delays if we sleep in low speed and wake in high
+	 * speed..
+	 */
+	no_schedule = 1;
+	sleep_freq = cur_freq;
+	if (cur_freq == low_freq && !is_pmu_based)
+		do_set_cpu_speed(CPUFREQ_HIGH, 0);
+	return 0;
+}
+
+static int pmac_cpufreq_resume(struct cpufreq_policy *policy)
+{
+	/* If we resume, first check if we have a get() function */
+	if (get_speed_proc)
+		cur_freq = get_speed_proc();
+	else
+		cur_freq = 0;
+
+	/* We don't, hrm... we don't really know our speed here, best
+	 * is that we force a switch to whatever it was, which is
+	 * probably high speed due to our suspend() routine
+	 */
+	do_set_cpu_speed(sleep_freq == low_freq ?
+			 CPUFREQ_LOW : CPUFREQ_HIGH, 0);
+
+	no_schedule = 0;
+	return 0;
+}
+
+static struct cpufreq_driver pmac_cpufreq_driver = {
+	.verify 	= pmac_cpufreq_verify,
+	.target 	= pmac_cpufreq_target,
+	.get		= pmac_cpufreq_get_speed,
+	.init		= pmac_cpufreq_cpu_init,
+	.suspend	= pmac_cpufreq_suspend,
+	.resume		= pmac_cpufreq_resume,
+	.flags		= CPUFREQ_PM_NO_WARN,
+	.attr		= pmac_cpu_freqs_attr,
+	.name		= "powermac",
+	.owner		= THIS_MODULE,
+};
+
+
+static int pmac_cpufreq_init_MacRISC3(struct device_node *cpunode)
+{
+	struct device_node *volt_gpio_np = of_find_node_by_name(NULL,
+								"voltage-gpio");
+	struct device_node *freq_gpio_np = of_find_node_by_name(NULL,
+								"frequency-gpio");
+	struct device_node *slew_done_gpio_np = of_find_node_by_name(NULL,
+								     "slewing-done");
+	u32 *value;
+
+	/*
+	 * Check to see if it's GPIO driven or PMU only
+	 *
+	 * The way we extract the GPIO address is slightly hackish, but it
+	 * works well enough for now. We need to abstract the whole GPIO
+	 * stuff sooner or later anyway
+	 */
+
+	if (volt_gpio_np)
+		voltage_gpio = read_gpio(volt_gpio_np);
+	if (freq_gpio_np)
+		frequency_gpio = read_gpio(freq_gpio_np);
+	if (slew_done_gpio_np)
+		slew_done_gpio = read_gpio(slew_done_gpio_np);
+
+	/* If we use the frequency GPIOs, calculate the min/max speeds based
+	 * on the bus frequencies
+	 */
+	if (frequency_gpio && slew_done_gpio) {
+		int lenp, rc;
+		u32 *freqs, *ratio;
+
+		freqs = (u32 *)get_property(cpunode, "bus-frequencies", &lenp);
+		lenp /= sizeof(u32);
+		if (freqs == NULL || lenp != 2) {
+			printk(KERN_ERR "cpufreq: bus-frequencies incorrect or missing\n");
+			return 1;
+		}
+		ratio = (u32 *)get_property(cpunode, "processor-to-bus-ratio*2", NULL);
+		if (ratio == NULL) {
+			printk(KERN_ERR "cpufreq: processor-to-bus-ratio*2 missing\n");
+			return 1;
+		}
+
+		/* Get the min/max bus frequencies */
+		low_freq = min(freqs[0], freqs[1]);
+		hi_freq = max(freqs[0], freqs[1]);
+
+		/* Grrrr.. It _seems_ that the device-tree is lying on the low bus
+		 * frequency, it claims it to be around 84Mhz on some models while
+		 * it appears to be approx. 101Mhz on all. Let's hack around here...
+		 * fortunately, we don't need to be too precise
+		 */
+		if (low_freq < 98000000)
+			low_freq = 101000000;
+			
+		/* Convert those to CPU core clocks */
+		low_freq = (low_freq * (*ratio)) / 2000;
+		hi_freq = (hi_freq * (*ratio)) / 2000;
+
+		/* Now we get the frequencies, we read the GPIO to see what is out current
+		 * speed
+		 */
+		rc = pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, frequency_gpio, 0);
+		cur_freq = (rc & 0x01) ? hi_freq : low_freq;
+
+		set_speed_proc = gpios_set_cpu_speed;
+		return 1;
+	}
+
+	/* If we use the PMU, look for the min & max frequencies in the
+	 * device-tree
+	 */
+	value = (u32 *)get_property(cpunode, "min-clock-frequency", NULL);
+	if (!value)
+		return 1;
+	low_freq = (*value) / 1000;
+	/* The PowerBook G4 12" (PowerBook6,1) has an error in the device-tree
+	 * here */
+	if (low_freq < 100000)
+		low_freq *= 10;
+
+	value = (u32 *)get_property(cpunode, "max-clock-frequency", NULL);
+	if (!value)
+		return 1;
+	hi_freq = (*value) / 1000;
+	set_speed_proc = pmu_set_cpu_speed;
+	is_pmu_based = 1;
+
+	return 0;
+}
+
+static int pmac_cpufreq_init_7447A(struct device_node *cpunode)
+{
+	struct device_node *volt_gpio_np;
+
+	if (get_property(cpunode, "dynamic-power-step", NULL) == NULL)
+		return 1;
+
+	volt_gpio_np = of_find_node_by_name(NULL, "cpu-vcore-select");
+	if (volt_gpio_np)
+		voltage_gpio = read_gpio(volt_gpio_np);
+	if (!voltage_gpio){
+		printk(KERN_ERR "cpufreq: missing cpu-vcore-select gpio\n");
+		return 1;
+	}
+
+	/* OF only reports the high frequency */
+	hi_freq = cur_freq;
+	low_freq = cur_freq/2;
+
+	/* Read actual frequency from CPU */
+	cur_freq = dfs_get_cpu_speed();
+	set_speed_proc = dfs_set_cpu_speed;
+	get_speed_proc = dfs_get_cpu_speed;
+
+	return 0;
+}
+
+static int pmac_cpufreq_init_750FX(struct device_node *cpunode)
+{
+	struct device_node *volt_gpio_np;
+	u32 pvr, *value;
+
+	if (get_property(cpunode, "dynamic-power-step", NULL) == NULL)
+		return 1;
+
+	hi_freq = cur_freq;
+	value = (u32 *)get_property(cpunode, "reduced-clock-frequency", NULL);
+	if (!value)
+		return 1;
+	low_freq = (*value) / 1000;
+
+	volt_gpio_np = of_find_node_by_name(NULL, "cpu-vcore-select");
+	if (volt_gpio_np)
+		voltage_gpio = read_gpio(volt_gpio_np);
+
+	pvr = mfspr(SPRN_PVR);
+	has_cpu_l2lve = !((pvr & 0xf00) == 0x100);
+
+	set_speed_proc = cpu_750fx_cpu_speed;
+	get_speed_proc = cpu_750fx_get_cpu_speed;
+	cur_freq = cpu_750fx_get_cpu_speed();
+
+	return 0;
+}
+
+/* Currently, we support the following machines:
+ *
+ *  - Titanium PowerBook 1Ghz (PMU based, 667Mhz & 1Ghz)
+ *  - Titanium PowerBook 800 (PMU based, 667Mhz & 800Mhz)
+ *  - Titanium PowerBook 400 (PMU based, 300Mhz & 400Mhz)
+ *  - Titanium PowerBook 500 (PMU based, 300Mhz & 500Mhz)
+ *  - iBook2 500/600 (PMU based, 400Mhz & 500/600Mhz)
+ *  - iBook2 700 (CPU based, 400Mhz & 700Mhz, support low voltage)
+ *  - Recent MacRISC3 laptops
+ *  - All new machines with 7447A CPUs
+ */
+static int __init pmac_cpufreq_setup(void)
+{
+	struct device_node	*cpunode;
+	u32			*value;
+
+	if (strstr(cmd_line, "nocpufreq"))
+		return 0;
+
+	/* Assume only one CPU */
+	cpunode = find_type_devices("cpu");
+	if (!cpunode)
+		goto out;
+
+	/* Get current cpu clock freq */
+	value = (u32 *)get_property(cpunode, "clock-frequency", NULL);
+	if (!value)
+		goto out;
+	cur_freq = (*value) / 1000;
+
+	/*  Check for 7447A based MacRISC3 */
+	if (machine_is_compatible("MacRISC3") &&
+	    get_property(cpunode, "dynamic-power-step", NULL) &&
+	    PVR_VER(mfspr(SPRN_PVR)) == 0x8003) {
+		pmac_cpufreq_init_7447A(cpunode);
+	/* Check for other MacRISC3 machines */
+	} else if (machine_is_compatible("PowerBook3,4") ||
+		   machine_is_compatible("PowerBook3,5") ||
+		   machine_is_compatible("MacRISC3")) {
+		pmac_cpufreq_init_MacRISC3(cpunode);
+	/* Else check for iBook2 500/600 */
+	} else if (machine_is_compatible("PowerBook4,1")) {
+		hi_freq = cur_freq;
+		low_freq = 400000;
+		set_speed_proc = pmu_set_cpu_speed;
+		is_pmu_based = 1;
+	}
+	/* Else check for TiPb 400 & 500 */
+	else if (machine_is_compatible("PowerBook3,2")) {
+		/* We only know about the 400 MHz and the 500Mhz model
+		 * they both have 300 MHz as low frequency
+		 */
+		if (cur_freq < 350000 || cur_freq > 550000)
+			goto out;
+		hi_freq = cur_freq;
+		low_freq = 300000;
+		set_speed_proc = pmu_set_cpu_speed;
+		is_pmu_based = 1;
+	}
+	/* Else check for 750FX */
+	else if (PVR_VER(mfspr(SPRN_PVR)) == 0x7000)
+		pmac_cpufreq_init_750FX(cpunode);
+out:
+	if (set_speed_proc == NULL)
+		return -ENODEV;
+
+	pmac_cpu_freqs[CPUFREQ_LOW].frequency = low_freq;
+	pmac_cpu_freqs[CPUFREQ_HIGH].frequency = hi_freq;
+
+	printk(KERN_INFO "Registering PowerMac CPU frequency driver\n");
+	printk(KERN_INFO "Low: %d Mhz, High: %d Mhz, Boot: %d Mhz\n",
+	       low_freq/1000, hi_freq/1000, cur_freq/1000);
+
+	return cpufreq_register_driver(&pmac_cpufreq_driver);
+}
+
+module_init(pmac_cpufreq_setup);
+