[linux-2.6-block.git] / drivers / cpufreq / sparc-us3-cpufreq.c

/* us3_cpufreq.c: UltraSPARC-III 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/init.h>

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

static struct cpufreq_driver *cpufreq_us3_driver;

struct us3_freq_percpu_info {
	struct cpufreq_frequency_table table[4];
};

/* Indexed by cpu number. */
static struct us3_freq_percpu_info *us3_freq_table;

/* UltraSPARC-III has three dividers: 1, 2, and 32.  These are controlled
 * in the Safari config register.
 */
#define SAFARI_CFG_DIV_1	0x0000000000000000UL
#define SAFARI_CFG_DIV_2	0x0000000040000000UL
#define SAFARI_CFG_DIV_32	0x0000000080000000UL
#define SAFARI_CFG_DIV_MASK	0x00000000C0000000UL

static void read_safari_cfg(void *arg)
{
	unsigned long ret, *val = arg;

	__asm__ __volatile__("ldxa	[%%g0] %1, %0"
			     : "=&r" (ret)
			     : "i" (ASI_SAFARI_CONFIG));
	*val = ret;
}

static void update_safari_cfg(void *arg)
{
	unsigned long reg, *new_bits = arg;

	read_safari_cfg(&reg);
	reg &= ~SAFARI_CFG_DIV_MASK;
	reg |= *new_bits;

	__asm__ __volatile__("stxa	%0, [%%g0] %1\n\t"
			     "membar	#Sync"
			     : /* no outputs */
			     : "r" (reg), "i" (ASI_SAFARI_CONFIG)
			     : "memory");
}

static unsigned long get_current_freq(unsigned int cpu, unsigned long safari_cfg)
{
	unsigned long clock_tick = sparc64_get_clock_tick(cpu) / 1000;
	unsigned long ret;

	switch (safari_cfg & SAFARI_CFG_DIV_MASK) {
	case SAFARI_CFG_DIV_1:
		ret = clock_tick / 1;
		break;
	case SAFARI_CFG_DIV_2:
		ret = clock_tick / 2;
		break;
	case SAFARI_CFG_DIV_32:
		ret = clock_tick / 32;
		break;
	default:
		BUG();
	}

	return ret;
}

static unsigned int us3_freq_get(unsigned int cpu)
{
	unsigned long reg;

	if (smp_call_function_single(cpu, read_safari_cfg, &reg, 1))
		return 0;
	return get_current_freq(cpu, reg);
}

static int us3_freq_target(struct cpufreq_policy *policy, unsigned int index)
{
	unsigned int cpu = policy->cpu;
	unsigned long new_bits, new_freq;

	new_freq = sparc64_get_clock_tick(cpu) / 1000;
	switch (index) {
	case 0:
		new_bits = SAFARI_CFG_DIV_1;
		new_freq /= 1;
		break;
	case 1:
		new_bits = SAFARI_CFG_DIV_2;
		new_freq /= 2;
		break;
	case 2:
		new_bits = SAFARI_CFG_DIV_32;
		new_freq /= 32;
		break;

	default:
		BUG();
	}

	return smp_call_function_single(cpu, update_safari_cfg, &new_bits, 1);
}

static int __init us3_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 =
		&us3_freq_table[cpu].table[0];

	table[0].driver_data = 0;
	table[0].frequency = clock_tick / 1;
	table[1].driver_data = 1;
	table[1].frequency = clock_tick / 2;
	table[2].driver_data = 2;
	table[2].frequency = clock_tick / 32;
	table[3].driver_data = 0;
	table[3].frequency = CPUFREQ_TABLE_END;

	policy->cpuinfo.transition_latency = 0;
	policy->cur = clock_tick;
	policy->freq_table = table;

	return 0;
}

static int us3_freq_cpu_exit(struct cpufreq_policy *policy)
{
	if (cpufreq_us3_driver)
		us3_freq_target(policy, 0);

	return 0;
}

static int __init us3_freq_init(void)
{
	unsigned long manuf, impl, ver;
	int ret;

	if (tlb_type != cheetah && tlb_type != cheetah_plus)
		return -ENODEV;

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

	if (manuf == CHEETAH_MANUF &&
	    (impl == CHEETAH_IMPL ||
	     impl == CHEETAH_PLUS_IMPL ||
	     impl == JAGUAR_IMPL ||
	     impl == PANTHER_IMPL)) {
		struct cpufreq_driver *driver;

		ret = -ENOMEM;
		driver = kzalloc(sizeof(*driver), GFP_KERNEL);
		if (!driver)
			goto err_out;

		us3_freq_table = kzalloc((NR_CPUS * sizeof(*us3_freq_table)),
			GFP_KERNEL);
		if (!us3_freq_table)
			goto err_out;

		driver->init = us3_freq_cpu_init;
		driver->verify = cpufreq_generic_frequency_table_verify;
		driver->target_index = us3_freq_target;
		driver->get = us3_freq_get;
		driver->exit = us3_freq_cpu_exit;
		strcpy(driver->name, "UltraSPARC-III");

		cpufreq_us3_driver = driver;
		ret = cpufreq_register_driver(driver);
		if (ret)
			goto err_out;

		return 0;

err_out:
		if (driver) {
			kfree(driver);
			cpufreq_us3_driver = NULL;
		}
		kfree(us3_freq_table);
		us3_freq_table = NULL;
		return ret;
	}

	return -ENODEV;
}

static void __exit us3_freq_exit(void)
{
	if (cpufreq_us3_driver) {
		cpufreq_unregister_driver(cpufreq_us3_driver);
		kfree(cpufreq_us3_driver);
		cpufreq_us3_driver = NULL;
		kfree(us3_freq_table);
		us3_freq_table = NULL;
	}
}

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

module_init(us3_freq_init);
module_exit(us3_freq_exit);
Commit	Line	Data
1da177e4 LT	1	/* us3_cpufreq.c: UltraSPARC-III cpu frequency support
	2	*
	3	* Copyright (C) 2003 David S. Miller (davem@redhat.com)
	4	*
	5	* Many thanks to Dominik Brodowski for fixing up the cpufreq
	6	* infrastructure in order to make this driver easier to implement.
	7	*/
	8
	9	#include <linux/kernel.h>
	10	#include <linux/module.h>
	11	#include <linux/sched.h>
	12	#include <linux/smp.h>
	13	#include <linux/cpufreq.h>
	14	#include <linux/threads.h>
	15	#include <linux/slab.h>
	16	#include <linux/init.h>
	17
	18	#include <asm/head.h>
	19	#include <asm/timer.h>
	20
	21	static struct cpufreq_driver *cpufreq_us3_driver;
	22
	23	struct us3_freq_percpu_info {
	24	struct cpufreq_frequency_table table[4];
	25	};
	26
	27	/* Indexed by cpu number. */
	28	static struct us3_freq_percpu_info *us3_freq_table;
	29
	30	/* UltraSPARC-III has three dividers: 1, 2, and 32. These are controlled
	31	* in the Safari config register.
	32	*/
	33	#define SAFARI_CFG_DIV_1 0x0000000000000000UL
	34	#define SAFARI_CFG_DIV_2 0x0000000040000000UL
	35	#define SAFARI_CFG_DIV_32 0x0000000080000000UL
	36	#define SAFARI_CFG_DIV_MASK 0x00000000C0000000UL
	37
9fe24c4e	38	static void read_safari_cfg(void *arg)
1da177e4	39	{
9fe24c4e	40	unsigned long ret, *val = arg;
1da177e4 LT	41
	42	__asm__ __volatile__("ldxa [%%g0] %1, %0"
	43	: "=&r" (ret)
	44	: "i" (ASI_SAFARI_CONFIG));
9fe24c4e	45	*val = ret;
1da177e4 LT	46	}
1da177e4 LT	47
9fe24c4e	48	static void update_safari_cfg(void *arg)
1da177e4	49	{
9fe24c4e TG	50	unsigned long reg, *new_bits = arg;
	51
	52	read_safari_cfg(&reg);
	53	reg &= ~SAFARI_CFG_DIV_MASK;
	54	reg \|= *new_bits;
	55
1da177e4 LT	56	__asm__ __volatile__("stxa %0, [%%g0] %1\n\t"
	57	"membar #Sync"
	58	: /* no outputs */
9fe24c4e	59	: "r" (reg), "i" (ASI_SAFARI_CONFIG)
1da177e4 LT	60	: "memory");
	61	}
	62
	63	static unsigned long get_current_freq(unsigned int cpu, unsigned long safari_cfg)
	64	{
2cab224d	65	unsigned long clock_tick = sparc64_get_clock_tick(cpu) / 1000;
1da177e4 LT	66	unsigned long ret;
	67
	68	switch (safari_cfg & SAFARI_CFG_DIV_MASK) {
	69	case SAFARI_CFG_DIV_1:
	70	ret = clock_tick / 1;
	71	break;
	72	case SAFARI_CFG_DIV_2:
	73	ret = clock_tick / 2;
	74	break;
	75	case SAFARI_CFG_DIV_32:
	76	ret = clock_tick / 32;
	77	break;
	78	default:
	79	BUG();
6cb79b3f	80	}
1da177e4 LT	81
	82	return ret;
	83	}
	84
2cab224d DM	85	static unsigned int us3_freq_get(unsigned int cpu)
2cab224d DM	86	{
2cab224d	87	unsigned long reg;
2cab224d	88
9fe24c4e TG	89	if (smp_call_function_single(cpu, read_safari_cfg, &reg, 1))
	90	return 0;
	91	return get_current_freq(cpu, reg);
2cab224d DM	92	}
2cab224d DM	93
9c0ebcf7	94	static int us3_freq_target(struct cpufreq_policy *policy, unsigned int index)
1da177e4	95	{
b43a7ffb	96	unsigned int cpu = policy->cpu;
9fe24c4e	97	unsigned long new_bits, new_freq;
1da177e4	98
2cab224d	99	new_freq = sparc64_get_clock_tick(cpu) / 1000;
1da177e4 LT	100	switch (index) {
	101	case 0:
	102	new_bits = SAFARI_CFG_DIV_1;
	103	new_freq /= 1;
	104	break;
	105	case 1:
	106	new_bits = SAFARI_CFG_DIV_2;
	107	new_freq /= 2;
	108	break;
	109	case 2:
	110	new_bits = SAFARI_CFG_DIV_32;
	111	new_freq /= 32;
	112	break;
	113
	114	default:
	115	BUG();
6cb79b3f	116	}
1da177e4	117
9fe24c4e	118	return smp_call_function_single(cpu, update_safari_cfg, &new_bits, 1);
1da177e4 LT	119	}
1da177e4 LT	120
1da177e4 LT	121	static int __init us3_freq_cpu_init(struct cpufreq_policy *policy)
	122	{
	123	unsigned int cpu = policy->cpu;
2cab224d	124	unsigned long clock_tick = sparc64_get_clock_tick(cpu) / 1000;
1da177e4 LT	125	struct cpufreq_frequency_table *table =
	126	&us3_freq_table[cpu].table[0];
	127
50701588	128	table[0].driver_data = 0;
1da177e4	129	table[0].frequency = clock_tick / 1;
50701588	130	table[1].driver_data = 1;
1da177e4	131	table[1].frequency = clock_tick / 2;
50701588	132	table[2].driver_data = 2;
1da177e4	133	table[2].frequency = clock_tick / 32;
50701588	134	table[3].driver_data = 0;
1da177e4 LT	135	table[3].frequency = CPUFREQ_TABLE_END;
1da177e4 LT	136
1da177e4 LT	137	policy->cpuinfo.transition_latency = 0;
1da177e4 LT	138	policy->cur = clock_tick;
31f4b7a8	139	policy->freq_table = table;
1da177e4	140
31f4b7a8	141	return 0;
1da177e4 LT	142	}
	143
	144	static int us3_freq_cpu_exit(struct cpufreq_policy *policy)
	145	{
e0b3165b	146	if (cpufreq_us3_driver)
9c0ebcf7	147	us3_freq_target(policy, 0);
1da177e4 LT	148
	149	return 0;
	150	}
	151
	152	static int __init us3_freq_init(void)
	153	{
	154	unsigned long manuf, impl, ver;
	155	int ret;
	156
d82ace7d DM	157	if (tlb_type != cheetah && tlb_type != cheetah_plus)
	158	return -ENODEV;
	159
1da177e4 LT	160	__asm__("rdpr %%ver, %0" : "=r" (ver));
	161	manuf = ((ver >> 48) & 0xffff);
	162	impl = ((ver >> 32) & 0xffff);
	163
	164	if (manuf == CHEETAH_MANUF &&
d2212bc7 DM	165	(impl == CHEETAH_IMPL \|\|
	166	impl == CHEETAH_PLUS_IMPL \|\|
	167	impl == JAGUAR_IMPL \|\|
	168	impl == PANTHER_IMPL)) {
1da177e4 LT	169	struct cpufreq_driver *driver;
	170
	171	ret = -ENOMEM;
d5b73cd8	172	driver = kzalloc(sizeof(*driver), GFP_KERNEL);
1da177e4 LT	173	if (!driver)
1da177e4 LT	174	goto err_out;
1da177e4	175
d5b73cd8	176	us3_freq_table = kzalloc((NR_CPUS * sizeof(*us3_freq_table)),
1da177e4 LT	177	GFP_KERNEL);
	178	if (!us3_freq_table)
	179	goto err_out;
	180
2cab224d	181	driver->init = us3_freq_cpu_init;
7a1874a0	182	driver->verify = cpufreq_generic_frequency_table_verify;
9c0ebcf7	183	driver->target_index = us3_freq_target;
2cab224d	184	driver->get = us3_freq_get;
1da177e4	185	driver->exit = us3_freq_cpu_exit;
1da177e4 LT	186	strcpy(driver->name, "UltraSPARC-III");
	187
	188	cpufreq_us3_driver = driver;
	189	ret = cpufreq_register_driver(driver);
	190	if (ret)
	191	goto err_out;
	192
	193	return 0;
	194
	195	err_out:
	196	if (driver) {
	197	kfree(driver);
	198	cpufreq_us3_driver = NULL;
	199	}
b2325fe1 JJ	200	kfree(us3_freq_table);
b2325fe1 JJ	201	us3_freq_table = NULL;
1da177e4 LT	202	return ret;
	203	}
	204
	205	return -ENODEV;
	206	}
	207
	208	static void __exit us3_freq_exit(void)
	209	{
	210	if (cpufreq_us3_driver) {
	211	cpufreq_unregister_driver(cpufreq_us3_driver);
1da177e4 LT	212	kfree(cpufreq_us3_driver);
	213	cpufreq_us3_driver = NULL;
	214	kfree(us3_freq_table);
	215	us3_freq_table = NULL;
	216	}
	217	}
	218
	219	MODULE_AUTHOR("David S. Miller <davem@redhat.com>");
	220	MODULE_DESCRIPTION("cpufreq driver for UltraSPARC-III");
	221	MODULE_LICENSE("GPL");
	222
	223	module_init(us3_freq_init);
	224	module_exit(us3_freq_exit);