[mirror_ubuntu-artful-kernel.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 unsigned long read_safari_cfg(void)
{
	unsigned long ret;

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

static void write_safari_cfg(unsigned long val)
{
	__asm__ __volatile__("stxa	%0, [%%g0] %1\n\t"
			     "membar	#Sync"
			     : /* no outputs */
			     : "r" (val), "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)
{
	cpumask_t cpus_allowed;
	unsigned long reg;
	unsigned int ret;

	cpumask_copy(&cpus_allowed, &current->cpus_allowed);
	set_cpus_allowed_ptr(current, cpumask_of(cpu));

	reg = read_safari_cfg();
	ret = get_current_freq(cpu, reg);

	set_cpus_allowed_ptr(current, &cpus_allowed);

	return ret;
}

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

	cpumask_copy(&cpus_allowed, &current->cpus_allowed);
	set_cpus_allowed_ptr(current, cpumask_of(cpu));

	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();
	}

	reg = read_safari_cfg();

	reg &= ~SAFARI_CFG_DIV_MASK;
	reg |= new_bits;
	write_safari_cfg(reg);

	set_cpus_allowed_ptr(current, &cpus_allowed);

	return 0;
}

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;

	return cpufreq_table_validate_and_show(policy, table);
}

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
	38	static unsigned long read_safari_cfg(void)
	39	{
	40	unsigned long ret;
	41
	42	__asm__ __volatile__("ldxa [%%g0] %1, %0"
	43	: "=&r" (ret)
	44	: "i" (ASI_SAFARI_CONFIG));
	45	return ret;
	46	}
	47
	48	static void write_safari_cfg(unsigned long val)
	49	{
	50	__asm__ __volatile__("stxa %0, [%%g0] %1\n\t"
	51	"membar #Sync"
	52	: /* no outputs */
	53	: "r" (val), "i" (ASI_SAFARI_CONFIG)
	54	: "memory");
	55	}
	56
	57	static unsigned long get_current_freq(unsigned int cpu, unsigned long safari_cfg)
	58	{
2cab224d	59	unsigned long clock_tick = sparc64_get_clock_tick(cpu) / 1000;
1da177e4 LT	60	unsigned long ret;
	61
	62	switch (safari_cfg & SAFARI_CFG_DIV_MASK) {
	63	case SAFARI_CFG_DIV_1:
	64	ret = clock_tick / 1;
	65	break;
	66	case SAFARI_CFG_DIV_2:
	67	ret = clock_tick / 2;
	68	break;
	69	case SAFARI_CFG_DIV_32:
	70	ret = clock_tick / 32;
	71	break;
	72	default:
	73	BUG();
6cb79b3f	74	}
1da177e4 LT	75
	76	return ret;
	77	}
	78
2cab224d DM	79	static unsigned int us3_freq_get(unsigned int cpu)
	80	{
	81	cpumask_t cpus_allowed;
	82	unsigned long reg;
	83	unsigned int ret;
	84
0c98d344	85	cpumask_copy(&cpus_allowed, &current->cpus_allowed);
d2566af8	86	set_cpus_allowed_ptr(current, cpumask_of(cpu));
2cab224d DM	87
	88	reg = read_safari_cfg();
	89	ret = get_current_freq(cpu, reg);
	90
d2566af8	91	set_cpus_allowed_ptr(current, &cpus_allowed);
2cab224d DM	92
	93	return ret;
	94	}
	95
9c0ebcf7	96	static int us3_freq_target(struct cpufreq_policy *policy, unsigned int index)
1da177e4	97	{
b43a7ffb	98	unsigned int cpu = policy->cpu;
1da177e4 LT	99	unsigned long new_bits, new_freq, reg;
1da177e4 LT	100	cpumask_t cpus_allowed;
1da177e4	101
0c98d344	102	cpumask_copy(&cpus_allowed, &current->cpus_allowed);
d2566af8	103	set_cpus_allowed_ptr(current, cpumask_of(cpu));
1da177e4	104
2cab224d	105	new_freq = sparc64_get_clock_tick(cpu) / 1000;
1da177e4 LT	106	switch (index) {
	107	case 0:
	108	new_bits = SAFARI_CFG_DIV_1;
	109	new_freq /= 1;
	110	break;
	111	case 1:
	112	new_bits = SAFARI_CFG_DIV_2;
	113	new_freq /= 2;
	114	break;
	115	case 2:
	116	new_bits = SAFARI_CFG_DIV_32;
	117	new_freq /= 32;
	118	break;
	119
	120	default:
	121	BUG();
6cb79b3f	122	}
1da177e4 LT	123
	124	reg = read_safari_cfg();
	125
1da177e4 LT	126	reg &= ~SAFARI_CFG_DIV_MASK;
	127	reg \|= new_bits;
	128	write_safari_cfg(reg);
	129
d2566af8	130	set_cpus_allowed_ptr(current, &cpus_allowed);
1da177e4 LT	131
	132	return 0;
	133	}
	134
1da177e4 LT	135	static int __init us3_freq_cpu_init(struct cpufreq_policy *policy)
	136	{
	137	unsigned int cpu = policy->cpu;
2cab224d	138	unsigned long clock_tick = sparc64_get_clock_tick(cpu) / 1000;
1da177e4 LT	139	struct cpufreq_frequency_table *table =
	140	&us3_freq_table[cpu].table[0];
	141
50701588	142	table[0].driver_data = 0;
1da177e4	143	table[0].frequency = clock_tick / 1;
50701588	144	table[1].driver_data = 1;
1da177e4	145	table[1].frequency = clock_tick / 2;
50701588	146	table[2].driver_data = 2;
1da177e4	147	table[2].frequency = clock_tick / 32;
50701588	148	table[3].driver_data = 0;
1da177e4 LT	149	table[3].frequency = CPUFREQ_TABLE_END;
1da177e4 LT	150
1da177e4 LT	151	policy->cpuinfo.transition_latency = 0;
	152	policy->cur = clock_tick;
	153
f1a707c0	154	return cpufreq_table_validate_and_show(policy, table);
1da177e4 LT	155	}
	156
	157	static int us3_freq_cpu_exit(struct cpufreq_policy *policy)
	158	{
e0b3165b	159	if (cpufreq_us3_driver)
9c0ebcf7	160	us3_freq_target(policy, 0);
1da177e4 LT	161
	162	return 0;
	163	}
	164
	165	static int __init us3_freq_init(void)
	166	{
	167	unsigned long manuf, impl, ver;
	168	int ret;
	169
d82ace7d DM	170	if (tlb_type != cheetah && tlb_type != cheetah_plus)
	171	return -ENODEV;
	172
1da177e4 LT	173	__asm__("rdpr %%ver, %0" : "=r" (ver));
	174	manuf = ((ver >> 48) & 0xffff);
	175	impl = ((ver >> 32) & 0xffff);
	176
	177	if (manuf == CHEETAH_MANUF &&
d2212bc7 DM	178	(impl == CHEETAH_IMPL \|\|
	179	impl == CHEETAH_PLUS_IMPL \|\|
	180	impl == JAGUAR_IMPL \|\|
	181	impl == PANTHER_IMPL)) {
1da177e4 LT	182	struct cpufreq_driver *driver;
	183
	184	ret = -ENOMEM;
d5b73cd8	185	driver = kzalloc(sizeof(*driver), GFP_KERNEL);
1da177e4 LT	186	if (!driver)
1da177e4 LT	187	goto err_out;
1da177e4	188
d5b73cd8	189	us3_freq_table = kzalloc((NR_CPUS * sizeof(*us3_freq_table)),
1da177e4 LT	190	GFP_KERNEL);
	191	if (!us3_freq_table)
	192	goto err_out;
	193
2cab224d	194	driver->init = us3_freq_cpu_init;
7a1874a0	195	driver->verify = cpufreq_generic_frequency_table_verify;
9c0ebcf7	196	driver->target_index = us3_freq_target;
2cab224d	197	driver->get = us3_freq_get;
1da177e4	198	driver->exit = us3_freq_cpu_exit;
1da177e4 LT	199	strcpy(driver->name, "UltraSPARC-III");
	200
	201	cpufreq_us3_driver = driver;
	202	ret = cpufreq_register_driver(driver);
	203	if (ret)
	204	goto err_out;
	205
	206	return 0;
	207
	208	err_out:
	209	if (driver) {
	210	kfree(driver);
	211	cpufreq_us3_driver = NULL;
	212	}
b2325fe1 JJ	213	kfree(us3_freq_table);
b2325fe1 JJ	214	us3_freq_table = NULL;
1da177e4 LT	215	return ret;
	216	}
	217
	218	return -ENODEV;
	219	}
	220
	221	static void __exit us3_freq_exit(void)
	222	{
	223	if (cpufreq_us3_driver) {
	224	cpufreq_unregister_driver(cpufreq_us3_driver);
1da177e4 LT	225	kfree(cpufreq_us3_driver);
	226	cpufreq_us3_driver = NULL;
	227	kfree(us3_freq_table);
	228	us3_freq_table = NULL;
	229	}
	230	}
	231
	232	MODULE_AUTHOR("David S. Miller <davem@redhat.com>");
	233	MODULE_DESCRIPTION("cpufreq driver for UltraSPARC-III");
	234	MODULE_LICENSE("GPL");
	235
	236	module_init(us3_freq_init);
	237	module_exit(us3_freq_exit);