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

// SPDX-License-Identifier: GPL-2.0-only
/* 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
09c434b8	1	// SPDX-License-Identifier: GPL-2.0-only
1da177e4 LT	2	/* us3_cpufreq.c: UltraSPARC-III cpu frequency support
	3	*
	4	* Copyright (C) 2003 David S. Miller (davem@redhat.com)
	5	*
	6	* Many thanks to Dominik Brodowski for fixing up the cpufreq
	7	* infrastructure in order to make this driver easier to implement.
	8	*/
	9
	10	#include <linux/kernel.h>
	11	#include <linux/module.h>
	12	#include <linux/sched.h>
	13	#include <linux/smp.h>
	14	#include <linux/cpufreq.h>
	15	#include <linux/threads.h>
	16	#include <linux/slab.h>
	17	#include <linux/init.h>
	18
	19	#include <asm/head.h>
	20	#include <asm/timer.h>
	21
	22	static struct cpufreq_driver *cpufreq_us3_driver;
	23
	24	struct us3_freq_percpu_info {
	25	struct cpufreq_frequency_table table[4];
	26	};
	27
	28	/* Indexed by cpu number. */
	29	static struct us3_freq_percpu_info *us3_freq_table;
	30
	31	/* UltraSPARC-III has three dividers: 1, 2, and 32. These are controlled
	32	* in the Safari config register.
	33	*/
	34	#define SAFARI_CFG_DIV_1 0x0000000000000000UL
	35	#define SAFARI_CFG_DIV_2 0x0000000040000000UL
	36	#define SAFARI_CFG_DIV_32 0x0000000080000000UL
	37	#define SAFARI_CFG_DIV_MASK 0x00000000C0000000UL
	38
9fe24c4e	39	static void read_safari_cfg(void *arg)
1da177e4	40	{
9fe24c4e	41	unsigned long ret, *val = arg;
1da177e4 LT	42
	43	__asm__ __volatile__("ldxa [%%g0] %1, %0"
	44	: "=&r" (ret)
	45	: "i" (ASI_SAFARI_CONFIG));
9fe24c4e	46	*val = ret;
1da177e4 LT	47	}
1da177e4 LT	48
9fe24c4e	49	static void update_safari_cfg(void *arg)
1da177e4	50	{
9fe24c4e TG	51	unsigned long reg, *new_bits = arg;
	52
	53	read_safari_cfg(&reg);
	54	reg &= ~SAFARI_CFG_DIV_MASK;
	55	reg \|= *new_bits;
	56
1da177e4 LT	57	__asm__ __volatile__("stxa %0, [%%g0] %1\n\t"
	58	"membar #Sync"
	59	: /* no outputs */
9fe24c4e	60	: "r" (reg), "i" (ASI_SAFARI_CONFIG)
1da177e4 LT	61	: "memory");
	62	}
	63
	64	static unsigned long get_current_freq(unsigned int cpu, unsigned long safari_cfg)
	65	{
2cab224d	66	unsigned long clock_tick = sparc64_get_clock_tick(cpu) / 1000;
1da177e4 LT	67	unsigned long ret;
	68
	69	switch (safari_cfg & SAFARI_CFG_DIV_MASK) {
	70	case SAFARI_CFG_DIV_1:
	71	ret = clock_tick / 1;
	72	break;
	73	case SAFARI_CFG_DIV_2:
	74	ret = clock_tick / 2;
	75	break;
	76	case SAFARI_CFG_DIV_32:
	77	ret = clock_tick / 32;
	78	break;
	79	default:
	80	BUG();
6cb79b3f	81	}
1da177e4 LT	82
	83	return ret;
	84	}
	85
2cab224d DM	86	static unsigned int us3_freq_get(unsigned int cpu)
2cab224d DM	87	{
2cab224d	88	unsigned long reg;
2cab224d	89
9fe24c4e TG	90	if (smp_call_function_single(cpu, read_safari_cfg, &reg, 1))
	91	return 0;
	92	return get_current_freq(cpu, reg);
2cab224d DM	93	}
2cab224d DM	94
9c0ebcf7	95	static int us3_freq_target(struct cpufreq_policy *policy, unsigned int index)
1da177e4	96	{
b43a7ffb	97	unsigned int cpu = policy->cpu;
9fe24c4e	98	unsigned long new_bits, new_freq;
1da177e4	99
2cab224d	100	new_freq = sparc64_get_clock_tick(cpu) / 1000;
1da177e4 LT	101	switch (index) {
	102	case 0:
	103	new_bits = SAFARI_CFG_DIV_1;
	104	new_freq /= 1;
	105	break;
	106	case 1:
	107	new_bits = SAFARI_CFG_DIV_2;
	108	new_freq /= 2;
	109	break;
	110	case 2:
	111	new_bits = SAFARI_CFG_DIV_32;
	112	new_freq /= 32;
	113	break;
	114
	115	default:
	116	BUG();
6cb79b3f	117	}
1da177e4	118
9fe24c4e	119	return smp_call_function_single(cpu, update_safari_cfg, &new_bits, 1);
1da177e4 LT	120	}
1da177e4 LT	121
1da177e4 LT	122	static int __init us3_freq_cpu_init(struct cpufreq_policy *policy)
	123	{
	124	unsigned int cpu = policy->cpu;
2cab224d	125	unsigned long clock_tick = sparc64_get_clock_tick(cpu) / 1000;
1da177e4 LT	126	struct cpufreq_frequency_table *table =
	127	&us3_freq_table[cpu].table[0];
	128
50701588	129	table[0].driver_data = 0;
1da177e4	130	table[0].frequency = clock_tick / 1;
50701588	131	table[1].driver_data = 1;
1da177e4	132	table[1].frequency = clock_tick / 2;
50701588	133	table[2].driver_data = 2;
1da177e4	134	table[2].frequency = clock_tick / 32;
50701588	135	table[3].driver_data = 0;
1da177e4 LT	136	table[3].frequency = CPUFREQ_TABLE_END;
1da177e4 LT	137
1da177e4 LT	138	policy->cpuinfo.transition_latency = 0;
1da177e4 LT	139	policy->cur = clock_tick;
31f4b7a8	140	policy->freq_table = table;
1da177e4	141
31f4b7a8	142	return 0;
1da177e4 LT	143	}
	144
	145	static int us3_freq_cpu_exit(struct cpufreq_policy *policy)
	146	{
e0b3165b	147	if (cpufreq_us3_driver)
9c0ebcf7	148	us3_freq_target(policy, 0);
1da177e4 LT	149
	150	return 0;
	151	}
	152
	153	static int __init us3_freq_init(void)
	154	{
	155	unsigned long manuf, impl, ver;
	156	int ret;
	157
d82ace7d DM	158	if (tlb_type != cheetah && tlb_type != cheetah_plus)
	159	return -ENODEV;
	160
1da177e4 LT	161	__asm__("rdpr %%ver, %0" : "=r" (ver));
	162	manuf = ((ver >> 48) & 0xffff);
	163	impl = ((ver >> 32) & 0xffff);
	164
	165	if (manuf == CHEETAH_MANUF &&
d2212bc7 DM	166	(impl == CHEETAH_IMPL \|\|
	167	impl == CHEETAH_PLUS_IMPL \|\|
	168	impl == JAGUAR_IMPL \|\|
	169	impl == PANTHER_IMPL)) {
1da177e4 LT	170	struct cpufreq_driver *driver;
	171
	172	ret = -ENOMEM;
d5b73cd8	173	driver = kzalloc(sizeof(*driver), GFP_KERNEL);
1da177e4 LT	174	if (!driver)
1da177e4 LT	175	goto err_out;
1da177e4	176
d5b73cd8	177	us3_freq_table = kzalloc((NR_CPUS * sizeof(*us3_freq_table)),
1da177e4 LT	178	GFP_KERNEL);
	179	if (!us3_freq_table)
	180	goto err_out;
	181
2cab224d	182	driver->init = us3_freq_cpu_init;
7a1874a0	183	driver->verify = cpufreq_generic_frequency_table_verify;
9c0ebcf7	184	driver->target_index = us3_freq_target;
2cab224d	185	driver->get = us3_freq_get;
1da177e4	186	driver->exit = us3_freq_cpu_exit;
1da177e4 LT	187	strcpy(driver->name, "UltraSPARC-III");
	188
	189	cpufreq_us3_driver = driver;
	190	ret = cpufreq_register_driver(driver);
	191	if (ret)
	192	goto err_out;
	193
	194	return 0;
	195
	196	err_out:
	197	if (driver) {
	198	kfree(driver);
	199	cpufreq_us3_driver = NULL;
	200	}
b2325fe1 JJ	201	kfree(us3_freq_table);
b2325fe1 JJ	202	us3_freq_table = NULL;
1da177e4 LT	203	return ret;
	204	}
	205
	206	return -ENODEV;
	207	}
	208
	209	static void __exit us3_freq_exit(void)
	210	{
	211	if (cpufreq_us3_driver) {
	212	cpufreq_unregister_driver(cpufreq_us3_driver);
1da177e4 LT	213	kfree(cpufreq_us3_driver);
	214	cpufreq_us3_driver = NULL;
	215	kfree(us3_freq_table);
	216	us3_freq_table = NULL;
	217	}
	218	}
	219
	220	MODULE_AUTHOR("David S. Miller <davem@redhat.com>");
	221	MODULE_DESCRIPTION("cpufreq driver for UltraSPARC-III");
	222	MODULE_LICENSE("GPL");
	223
	224	module_init(us3_freq_init);
	225	module_exit(us3_freq_exit);