arch/sparc64/kernel/us2e_cpufreq.c - arm/linux-arm64-legacy - Git at Google

 /* us2e_cpufreq.c: UltraSPARC-IIe cpu frequency support
  *
  * Copyright (C) 2003 David S. Miller (davem@redhat.com)
  *
  * Many thanks to Dominik Brodowski for fixing up the cpufreq
  * infrastructure in order to make this driver easier to implement.
  */

 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/sched.h>
 #include <linux/smp.h>
 #include <linux/cpufreq.h>
 #include <linux/threads.h>
 #include <linux/slab.h>
 #include <linux/delay.h>
 #include <linux/init.h>

 #include <asm/asi.h>
 #include <asm/timer.h>

 static struct cpufreq_driver *cpufreq_us2e_driver;

 struct us2e_freq_percpu_info {
 	struct cpufreq_frequency_table table[6];
 };

 /* Indexed by cpu number. */
 static struct us2e_freq_percpu_info *us2e_freq_table;

 #define HBIRD_MEM_CNTL0_ADDR	0x1fe0000f010UL
 #define HBIRD_ESTAR_MODE_ADDR	0x1fe0000f080UL

 /* UltraSPARC-IIe has five dividers: 1, 2, 4, 6, and 8.  These are controlled
  * in the ESTAR mode control register.
  */
 #define ESTAR_MODE_DIV_1	0x0000000000000000UL
 #define ESTAR_MODE_DIV_2	0x0000000000000001UL
 #define ESTAR_MODE_DIV_4	0x0000000000000003UL
 #define ESTAR_MODE_DIV_6	0x0000000000000002UL
 #define ESTAR_MODE_DIV_8	0x0000000000000004UL
 #define ESTAR_MODE_DIV_MASK	0x0000000000000007UL

 #define MCTRL0_SREFRESH_ENAB	0x0000000000010000UL
 #define MCTRL0_REFR_COUNT_MASK	0x0000000000007f00UL
 #define MCTRL0_REFR_COUNT_SHIFT	8
 #define MCTRL0_REFR_INTERVAL	7800
 #define MCTRL0_REFR_CLKS_P_CNT	64

 static unsigned long read_hbreg(unsigned long addr)
 {
 	unsigned long ret;

 	__asm__ __volatile__("ldxa	[%1] %2, %0"
 			     : "=&r" (ret)
 			     : "r" (addr), "i" (ASI_PHYS_BYPASS_EC_E));
 	return ret;
 }

 static void write_hbreg(unsigned long addr, unsigned long val)
 {
 	__asm__ __volatile__("stxa	%0, [%1] %2\n\t"
 			     "membar	#Sync"
 			     : /* no outputs */
 			     : "r" (val), "r" (addr), "i" (ASI_PHYS_BYPASS_EC_E)
 			     : "memory");
 	if (addr == HBIRD_ESTAR_MODE_ADDR) {
 		/* Need to wait 16 clock cycles for the PLL to lock.  */
 		udelay(1);
 	}
 }

 static void self_refresh_ctl(int enable)
 {
 	unsigned long mctrl = read_hbreg(HBIRD_MEM_CNTL0_ADDR);

 	if (enable)
 		mctrl |= MCTRL0_SREFRESH_ENAB;
 	else
 		mctrl &= ~MCTRL0_SREFRESH_ENAB;
 	write_hbreg(HBIRD_MEM_CNTL0_ADDR, mctrl);
 	(void) read_hbreg(HBIRD_MEM_CNTL0_ADDR);
 }

 static void frob_mem_refresh(int cpu_slowing_down,
 			     unsigned long clock_tick,
 			     unsigned long old_divisor, unsigned long divisor)
 {
 	unsigned long old_refr_count, refr_count, mctrl;

 	refr_count  = (clock_tick * MCTRL0_REFR_INTERVAL);
 	refr_count /= (MCTRL0_REFR_CLKS_P_CNT * divisor * 1000000000UL);

 	mctrl = read_hbreg(HBIRD_MEM_CNTL0_ADDR);
 	old_refr_count = (mctrl & MCTRL0_REFR_COUNT_MASK)
 		>> MCTRL0_REFR_COUNT_SHIFT;

 	mctrl &= ~MCTRL0_REFR_COUNT_MASK;
 	mctrl |= refr_count << MCTRL0_REFR_COUNT_SHIFT;
 	write_hbreg(HBIRD_MEM_CNTL0_ADDR, mctrl);
 	mctrl = read_hbreg(HBIRD_MEM_CNTL0_ADDR);

 	if (cpu_slowing_down && !(mctrl & MCTRL0_SREFRESH_ENAB)) {
 		unsigned long usecs;

 		/* We have to wait for both refresh counts (old
 		 * and new) to go to zero.
 		 */
 		usecs = (MCTRL0_REFR_CLKS_P_CNT *
 			 (refr_count + old_refr_count) *
 			 1000000UL *
 			 old_divisor) / clock_tick;
 		udelay(usecs + 1UL);
 	}
 }

 static void us2e_transition(unsigned long estar, unsigned long new_bits,
 			    unsigned long clock_tick,
 			    unsigned long old_divisor, unsigned long divisor)
 {
 	unsigned long flags;

 	local_irq_save(flags);

 	estar &= ~ESTAR_MODE_DIV_MASK;

 	/* This is based upon the state transition diagram in the IIe manual.  */
 	if (old_divisor == 2 && divisor == 1) {
 		self_refresh_ctl(0);
 		write_hbreg(HBIRD_ESTAR_MODE_ADDR, estar | new_bits);
 		frob_mem_refresh(0, clock_tick, old_divisor, divisor);
 	} else if (old_divisor == 1 && divisor == 2) {
 		frob_mem_refresh(1, clock_tick, old_divisor, divisor);
 		write_hbreg(HBIRD_ESTAR_MODE_ADDR, estar | new_bits);
 		self_refresh_ctl(1);
 	} else if (old_divisor == 1 && divisor > 2) {
 		us2e_transition(estar, ESTAR_MODE_DIV_2, clock_tick,
 				1, 2);
 		us2e_transition(estar, new_bits, clock_tick,
 				2, divisor);
 	} else if (old_divisor > 2 && divisor == 1) {
 		us2e_transition(estar, ESTAR_MODE_DIV_2, clock_tick,
 				old_divisor, 2);
 		us2e_transition(estar, new_bits, clock_tick,
 				2, divisor);
 	} else if (old_divisor < divisor) {
 		frob_mem_refresh(0, clock_tick, old_divisor, divisor);
 		write_hbreg(HBIRD_ESTAR_MODE_ADDR, estar | new_bits);
 	} else if (old_divisor > divisor) {
 		write_hbreg(HBIRD_ESTAR_MODE_ADDR, estar | new_bits);
 		frob_mem_refresh(1, clock_tick, old_divisor, divisor);
 	} else {
 		BUG();
 	}

 	local_irq_restore(flags);
 }

 static unsigned long index_to_estar_mode(unsigned int index)
 {
 	switch (index) {
 	case 0:
 		return ESTAR_MODE_DIV_1;

 	case 1:
 		return ESTAR_MODE_DIV_2;

 	case 2:
 		return ESTAR_MODE_DIV_4;

 	case 3:
 		return ESTAR_MODE_DIV_6;

 	case 4:
 		return ESTAR_MODE_DIV_8;

 	default:
 		BUG();
 	};
 }

 static unsigned long index_to_divisor(unsigned int index)
 {
 	switch (index) {
 	case 0:
 		return 1;

 	case 1:
 		return 2;

 	case 2:
 		return 4;

 	case 3:
 		return 6;

 	case 4:
 		return 8;

 	default:
 		BUG();
 	};
 }

 static unsigned long estar_to_divisor(unsigned long estar)
 {
 	unsigned long ret;

 	switch (estar & ESTAR_MODE_DIV_MASK) {
 	case ESTAR_MODE_DIV_1:
 		ret = 1;
 		break;
 	case ESTAR_MODE_DIV_2:
 		ret = 2;
 		break;
 	case ESTAR_MODE_DIV_4:
 		ret = 4;
 		break;
 	case ESTAR_MODE_DIV_6:
 		ret = 6;
 		break;
 	case ESTAR_MODE_DIV_8:
 		ret = 8;
 		break;
 	default:
 		BUG();
 	};

 	return ret;
 }

 static unsigned int us2e_freq_get(unsigned int cpu)
 {
 	cpumask_t cpus_allowed;
 	unsigned long clock_tick, estar;

 	if (!cpu_online(cpu))
 		return 0;

 	cpus_allowed = current->cpus_allowed;
 	set_cpus_allowed(current, cpumask_of_cpu(cpu));

 	clock_tick = sparc64_get_clock_tick(cpu) / 1000;
 	estar = read_hbreg(HBIRD_ESTAR_MODE_ADDR);

 	set_cpus_allowed(current, cpus_allowed);

 	return clock_tick / estar_to_divisor(estar);
 }

 static void us2e_set_cpu_divider_index(unsigned int cpu, unsigned int index)
 {
 	unsigned long new_bits, new_freq;
 	unsigned long clock_tick, divisor, old_divisor, estar;
 	cpumask_t cpus_allowed;
 	struct cpufreq_freqs freqs;

 	if (!cpu_online(cpu))
 		return;

 	cpus_allowed = current->cpus_allowed;
 	set_cpus_allowed(current, cpumask_of_cpu(cpu));

 	new_freq = clock_tick = sparc64_get_clock_tick(cpu) / 1000;
 	new_bits = index_to_estar_mode(index);
 	divisor = index_to_divisor(index);
 	new_freq /= divisor;

 	estar = read_hbreg(HBIRD_ESTAR_MODE_ADDR);

 	old_divisor = estar_to_divisor(estar);

 	freqs.old = clock_tick / old_divisor;
 	freqs.new = new_freq;
 	freqs.cpu = cpu;
 	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);

 	if (old_divisor != divisor)
 		us2e_transition(estar, new_bits, clock_tick * 1000,
 				old_divisor, divisor);

 	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);

 	set_cpus_allowed(current, cpus_allowed);
 }

 static int us2e_freq_target(struct cpufreq_policy *policy,
 			  unsigned int target_freq,
 			  unsigned int relation)
 {
 	unsigned int new_index = 0;

 	if (cpufreq_frequency_table_target(policy,
 					   &us2e_freq_table[policy->cpu].table[0],
 					   target_freq, relation, &new_index))
 		return -EINVAL;

 	us2e_set_cpu_divider_index(policy->cpu, new_index);

 	return 0;
 }

 static int us2e_freq_verify(struct cpufreq_policy *policy)
 {
 	return cpufreq_frequency_table_verify(policy,
 					      &us2e_freq_table[policy->cpu].table[0]);
 }

 static int __init us2e_freq_cpu_init(struct cpufreq_policy *policy)
 {
 	unsigned int cpu = policy->cpu;
 	unsigned long clock_tick = sparc64_get_clock_tick(cpu) / 1000;
 	struct cpufreq_frequency_table *table =
 		&us2e_freq_table[cpu].table[0];

 	table[0].index = 0;
 	table[0].frequency = clock_tick / 1;
 	table[1].index = 1;
 	table[1].frequency = clock_tick / 2;
 	table[2].index = 2;
 	table[2].frequency = clock_tick / 4;
 	table[2].index = 3;
 	table[2].frequency = clock_tick / 6;
 	table[2].index = 4;
 	table[2].frequency = clock_tick / 8;
 	table[2].index = 5;
 	table[3].frequency = CPUFREQ_TABLE_END;

 	policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
 	policy->cpuinfo.transition_latency = 0;
 	policy->cur = clock_tick;

 	return cpufreq_frequency_table_cpuinfo(policy, table);
 }

 static int us2e_freq_cpu_exit(struct cpufreq_policy *policy)
 {
 	if (cpufreq_us2e_driver)
 		us2e_set_cpu_divider_index(policy->cpu, 0);

 	return 0;
 }

 static int __init us2e_freq_init(void)
 {
 	unsigned long manuf, impl, ver;
 	int ret;

 	__asm__("rdpr %%ver, %0" : "=r" (ver));
 	manuf = ((ver >> 48) & 0xffff);
 	impl  = ((ver >> 32) & 0xffff);

 	if (manuf == 0x17 && impl == 0x13) {
 		struct cpufreq_driver *driver;

 		ret = -ENOMEM;
 		driver = kmalloc(sizeof(struct cpufreq_driver), GFP_KERNEL);
 		if (!driver)
 			goto err_out;
 		memset(driver, 0, sizeof(*driver));

 		us2e_freq_table = kmalloc(
 			(NR_CPUS * sizeof(struct us2e_freq_percpu_info)),
 			GFP_KERNEL);
 		if (!us2e_freq_table)
 			goto err_out;

 		memset(us2e_freq_table, 0,
 		       (NR_CPUS * sizeof(struct us2e_freq_percpu_info)));

 		driver->init = us2e_freq_cpu_init;
 		driver->verify = us2e_freq_verify;
 		driver->target = us2e_freq_target;
 		driver->get = us2e_freq_get;
 		driver->exit = us2e_freq_cpu_exit;
 		driver->owner = THIS_MODULE,
 		strcpy(driver->name, "UltraSPARC-IIe");

 		cpufreq_us2e_driver = driver;
 		ret = cpufreq_register_driver(driver);
 		if (ret)
 			goto err_out;

 		return 0;

 err_out:
 		if (driver) {
 			kfree(driver);
 			cpufreq_us2e_driver = NULL;
 		}
 		kfree(us2e_freq_table);
 		us2e_freq_table = NULL;
 		return ret;
 	}

 	return -ENODEV;
 }

 static void __exit us2e_freq_exit(void)
 {
 	if (cpufreq_us2e_driver) {
 		cpufreq_unregister_driver(cpufreq_us2e_driver);
 		kfree(cpufreq_us2e_driver);
 		cpufreq_us2e_driver = NULL;
 		kfree(us2e_freq_table);
 		us2e_freq_table = NULL;
 	}
 }

 MODULE_AUTHOR("David S. Miller <davem@redhat.com>");
 MODULE_DESCRIPTION("cpufreq driver for UltraSPARC-IIe");
 MODULE_LICENSE("GPL");

 module_init(us2e_freq_init);
 module_exit(us2e_freq_exit);
	/* us2e_cpufreq.c: UltraSPARC-IIe cpu frequency support
	*
	* Copyright (C) 2003 David S. Miller (davem@redhat.com)
	*
	* Many thanks to Dominik Brodowski for fixing up the cpufreq
	* infrastructure in order to make this driver easier to implement.
	*/

	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/sched.h>
	#include <linux/smp.h>
	#include <linux/cpufreq.h>
	#include <linux/threads.h>
	#include <linux/slab.h>
	#include <linux/delay.h>
	#include <linux/init.h>

	#include <asm/asi.h>
	#include <asm/timer.h>

	static struct cpufreq_driver *cpufreq_us2e_driver;

	struct us2e_freq_percpu_info {
	struct cpufreq_frequency_table table[6];
	};

	/* Indexed by cpu number. */
	static struct us2e_freq_percpu_info *us2e_freq_table;

	#define HBIRD_MEM_CNTL0_ADDR 0x1fe0000f010UL
	#define HBIRD_ESTAR_MODE_ADDR 0x1fe0000f080UL

	/* UltraSPARC-IIe has five dividers: 1, 2, 4, 6, and 8. These are controlled
	* in the ESTAR mode control register.
	*/
	#define ESTAR_MODE_DIV_1 0x0000000000000000UL
	#define ESTAR_MODE_DIV_2 0x0000000000000001UL
	#define ESTAR_MODE_DIV_4 0x0000000000000003UL
	#define ESTAR_MODE_DIV_6 0x0000000000000002UL
	#define ESTAR_MODE_DIV_8 0x0000000000000004UL
	#define ESTAR_MODE_DIV_MASK 0x0000000000000007UL

	#define MCTRL0_SREFRESH_ENAB 0x0000000000010000UL
	#define MCTRL0_REFR_COUNT_MASK 0x0000000000007f00UL
	#define MCTRL0_REFR_COUNT_SHIFT 8
	#define MCTRL0_REFR_INTERVAL 7800
	#define MCTRL0_REFR_CLKS_P_CNT 64

	static unsigned long read_hbreg(unsigned long addr)
	{
	unsigned long ret;

	__asm__ __volatile__("ldxa [%1] %2, %0"
	: "=&r" (ret)
	: "r" (addr), "i" (ASI_PHYS_BYPASS_EC_E));
	return ret;
	}

	static void write_hbreg(unsigned long addr, unsigned long val)
	{
	__asm__ __volatile__("stxa %0, [%1] %2\n\t"
	"membar #Sync"
	: /* no outputs */
	: "r" (val), "r" (addr), "i" (ASI_PHYS_BYPASS_EC_E)
	: "memory");
	if (addr == HBIRD_ESTAR_MODE_ADDR) {
	/* Need to wait 16 clock cycles for the PLL to lock. */
	udelay(1);
	}
	}

	static void self_refresh_ctl(int enable)
	{
	unsigned long mctrl = read_hbreg(HBIRD_MEM_CNTL0_ADDR);

	if (enable)
	mctrl \|= MCTRL0_SREFRESH_ENAB;
	else
	mctrl &= ~MCTRL0_SREFRESH_ENAB;
	write_hbreg(HBIRD_MEM_CNTL0_ADDR, mctrl);
	(void) read_hbreg(HBIRD_MEM_CNTL0_ADDR);
	}

	static void frob_mem_refresh(int cpu_slowing_down,
	unsigned long clock_tick,
	unsigned long old_divisor, unsigned long divisor)
	{
	unsigned long old_refr_count, refr_count, mctrl;

	refr_count = (clock_tick * MCTRL0_REFR_INTERVAL);
	refr_count /= (MCTRL0_REFR_CLKS_P_CNT * divisor * 1000000000UL);

	mctrl = read_hbreg(HBIRD_MEM_CNTL0_ADDR);
	old_refr_count = (mctrl & MCTRL0_REFR_COUNT_MASK)
	>> MCTRL0_REFR_COUNT_SHIFT;

	mctrl &= ~MCTRL0_REFR_COUNT_MASK;
	mctrl \|= refr_count << MCTRL0_REFR_COUNT_SHIFT;
	write_hbreg(HBIRD_MEM_CNTL0_ADDR, mctrl);
	mctrl = read_hbreg(HBIRD_MEM_CNTL0_ADDR);

	if (cpu_slowing_down && !(mctrl & MCTRL0_SREFRESH_ENAB)) {
	unsigned long usecs;

	/* We have to wait for both refresh counts (old
	* and new) to go to zero.
	*/
	usecs = (MCTRL0_REFR_CLKS_P_CNT *
	(refr_count + old_refr_count) *
	1000000UL *
	old_divisor) / clock_tick;
	udelay(usecs + 1UL);
	}
	}

	static void us2e_transition(unsigned long estar, unsigned long new_bits,
	unsigned long clock_tick,
	unsigned long old_divisor, unsigned long divisor)
	{
	unsigned long flags;

	local_irq_save(flags);

	estar &= ~ESTAR_MODE_DIV_MASK;

	/* This is based upon the state transition diagram in the IIe manual. */
	if (old_divisor == 2 && divisor == 1) {
	self_refresh_ctl(0);
	write_hbreg(HBIRD_ESTAR_MODE_ADDR, estar \| new_bits);
	frob_mem_refresh(0, clock_tick, old_divisor, divisor);
	} else if (old_divisor == 1 && divisor == 2) {
	frob_mem_refresh(1, clock_tick, old_divisor, divisor);
	write_hbreg(HBIRD_ESTAR_MODE_ADDR, estar \| new_bits);
	self_refresh_ctl(1);
	} else if (old_divisor == 1 && divisor > 2) {
	us2e_transition(estar, ESTAR_MODE_DIV_2, clock_tick,
	1, 2);
	us2e_transition(estar, new_bits, clock_tick,
	2, divisor);
	} else if (old_divisor > 2 && divisor == 1) {
	us2e_transition(estar, ESTAR_MODE_DIV_2, clock_tick,
	old_divisor, 2);
	us2e_transition(estar, new_bits, clock_tick,
	2, divisor);
	} else if (old_divisor < divisor) {
	frob_mem_refresh(0, clock_tick, old_divisor, divisor);
	write_hbreg(HBIRD_ESTAR_MODE_ADDR, estar \| new_bits);
	} else if (old_divisor > divisor) {
	write_hbreg(HBIRD_ESTAR_MODE_ADDR, estar \| new_bits);
	frob_mem_refresh(1, clock_tick, old_divisor, divisor);
	} else {
	BUG();
	}

	local_irq_restore(flags);
	}

	static unsigned long index_to_estar_mode(unsigned int index)
	{
	switch (index) {
	case 0:
	return ESTAR_MODE_DIV_1;

	case 1:
	return ESTAR_MODE_DIV_2;

	case 2:
	return ESTAR_MODE_DIV_4;

	case 3:
	return ESTAR_MODE_DIV_6;

	case 4:
	return ESTAR_MODE_DIV_8;

	default:
	BUG();
	};
	}

	static unsigned long index_to_divisor(unsigned int index)
	{
	switch (index) {
	case 0:
	return 1;

	case 1:
	return 2;

	case 2:
	return 4;

	case 3:
	return 6;

	case 4:
	return 8;

	default:
	BUG();
	};
	}

	static unsigned long estar_to_divisor(unsigned long estar)
	{
	unsigned long ret;

	switch (estar & ESTAR_MODE_DIV_MASK) {
	case ESTAR_MODE_DIV_1:
	ret = 1;
	break;
	case ESTAR_MODE_DIV_2:
	ret = 2;
	break;
	case ESTAR_MODE_DIV_4:
	ret = 4;
	break;
	case ESTAR_MODE_DIV_6:
	ret = 6;
	break;
	case ESTAR_MODE_DIV_8:
	ret = 8;
	break;
	default:
	BUG();
	};

	return ret;
	}

	static unsigned int us2e_freq_get(unsigned int cpu)
	{
	cpumask_t cpus_allowed;
	unsigned long clock_tick, estar;

	if (!cpu_online(cpu))
	return 0;

	cpus_allowed = current->cpus_allowed;
	set_cpus_allowed(current, cpumask_of_cpu(cpu));

	clock_tick = sparc64_get_clock_tick(cpu) / 1000;
	estar = read_hbreg(HBIRD_ESTAR_MODE_ADDR);

	set_cpus_allowed(current, cpus_allowed);

	return clock_tick / estar_to_divisor(estar);
	}

	static void us2e_set_cpu_divider_index(unsigned int cpu, unsigned int index)
	{
	unsigned long new_bits, new_freq;
	unsigned long clock_tick, divisor, old_divisor, estar;
	cpumask_t cpus_allowed;
	struct cpufreq_freqs freqs;

	if (!cpu_online(cpu))
	return;

	cpus_allowed = current->cpus_allowed;
	set_cpus_allowed(current, cpumask_of_cpu(cpu));

	new_freq = clock_tick = sparc64_get_clock_tick(cpu) / 1000;
	new_bits = index_to_estar_mode(index);
	divisor = index_to_divisor(index);
	new_freq /= divisor;

	estar = read_hbreg(HBIRD_ESTAR_MODE_ADDR);

	old_divisor = estar_to_divisor(estar);

	freqs.old = clock_tick / old_divisor;
	freqs.new = new_freq;
	freqs.cpu = cpu;
	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);

	if (old_divisor != divisor)
	us2e_transition(estar, new_bits, clock_tick * 1000,
	old_divisor, divisor);

	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);

	set_cpus_allowed(current, cpus_allowed);
	}

	static int us2e_freq_target(struct cpufreq_policy *policy,
	unsigned int target_freq,
	unsigned int relation)
	{
	unsigned int new_index = 0;

	if (cpufreq_frequency_table_target(policy,
	&us2e_freq_table[policy->cpu].table[0],
	target_freq, relation, &new_index))
	return -EINVAL;

	us2e_set_cpu_divider_index(policy->cpu, new_index);

	return 0;
	}

	static int us2e_freq_verify(struct cpufreq_policy *policy)
	{
	return cpufreq_frequency_table_verify(policy,
	&us2e_freq_table[policy->cpu].table[0]);
	}

	static int __init us2e_freq_cpu_init(struct cpufreq_policy *policy)
	{
	unsigned int cpu = policy->cpu;
	unsigned long clock_tick = sparc64_get_clock_tick(cpu) / 1000;
	struct cpufreq_frequency_table *table =
	&us2e_freq_table[cpu].table[0];

	table[0].index = 0;
	table[0].frequency = clock_tick / 1;
	table[1].index = 1;
	table[1].frequency = clock_tick / 2;
	table[2].index = 2;
	table[2].frequency = clock_tick / 4;
	table[2].index = 3;
	table[2].frequency = clock_tick / 6;
	table[2].index = 4;
	table[2].frequency = clock_tick / 8;
	table[2].index = 5;
	table[3].frequency = CPUFREQ_TABLE_END;

	policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
	policy->cpuinfo.transition_latency = 0;
	policy->cur = clock_tick;

	return cpufreq_frequency_table_cpuinfo(policy, table);
	}

	static int us2e_freq_cpu_exit(struct cpufreq_policy *policy)
	{
	if (cpufreq_us2e_driver)
	us2e_set_cpu_divider_index(policy->cpu, 0);

	return 0;
	}

	static int __init us2e_freq_init(void)
	{
	unsigned long manuf, impl, ver;
	int ret;

	__asm__("rdpr %%ver, %0" : "=r" (ver));
	manuf = ((ver >> 48) & 0xffff);
	impl = ((ver >> 32) & 0xffff);

	if (manuf == 0x17 && impl == 0x13) {
	struct cpufreq_driver *driver;

	ret = -ENOMEM;
	driver = kmalloc(sizeof(struct cpufreq_driver), GFP_KERNEL);
	if (!driver)
	goto err_out;
	memset(driver, 0, sizeof(*driver));

	us2e_freq_table = kmalloc(
	(NR_CPUS * sizeof(struct us2e_freq_percpu_info)),
	GFP_KERNEL);
	if (!us2e_freq_table)
	goto err_out;

	memset(us2e_freq_table, 0,
	(NR_CPUS * sizeof(struct us2e_freq_percpu_info)));

	driver->init = us2e_freq_cpu_init;
	driver->verify = us2e_freq_verify;
	driver->target = us2e_freq_target;
	driver->get = us2e_freq_get;
	driver->exit = us2e_freq_cpu_exit;
	driver->owner = THIS_MODULE,
	strcpy(driver->name, "UltraSPARC-IIe");

	cpufreq_us2e_driver = driver;
	ret = cpufreq_register_driver(driver);
	if (ret)
	goto err_out;

	return 0;

	err_out:
	if (driver) {
	kfree(driver);
	cpufreq_us2e_driver = NULL;
	}
	kfree(us2e_freq_table);
	us2e_freq_table = NULL;
	return ret;
	}

	return -ENODEV;
	}

	static void __exit us2e_freq_exit(void)
	{
	if (cpufreq_us2e_driver) {
	cpufreq_unregister_driver(cpufreq_us2e_driver);
	kfree(cpufreq_us2e_driver);
	cpufreq_us2e_driver = NULL;
	kfree(us2e_freq_table);
	us2e_freq_table = NULL;
	}
	}

	MODULE_AUTHOR("David S. Miller <davem@redhat.com>");
	MODULE_DESCRIPTION("cpufreq driver for UltraSPARC-IIe");
	MODULE_LICENSE("GPL");

	module_init(us2e_freq_init);
	module_exit(us2e_freq_exit);