[GitHub/LineageOS/android_kernel_motorola_exynos9610.git] / drivers / cpufreq / loongson2_cpufreq.c

/*
 * Cpufreq driver for the loongson-2 processors
 *
 * The 2E revision of loongson processor not support this feature.
 *
 * Copyright (C) 2006 - 2008 Lemote Inc. & Institute of Computing Technology
 * Author: Yanhua, yanh@lemote.com
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/cpufreq.h>
#include <linux/module.h>
#include <linux/err.h>
#include <linux/sched.h>	/* set_cpus_allowed() */
#include <linux/delay.h>
#include <linux/platform_device.h>

#include <asm/clock.h>
#include <asm/idle.h>

#include <asm/mach-loongson64/loongson.h>

static uint nowait;

static void (*saved_cpu_wait) (void);

static int loongson2_cpu_freq_notifier(struct notifier_block *nb,
					unsigned long val, void *data);

static struct notifier_block loongson2_cpufreq_notifier_block = {
	.notifier_call = loongson2_cpu_freq_notifier
};

static int loongson2_cpu_freq_notifier(struct notifier_block *nb,
					unsigned long val, void *data)
{
	if (val == CPUFREQ_POSTCHANGE)
		current_cpu_data.udelay_val = loops_per_jiffy;

	return 0;
}

/*
 * Here we notify other drivers of the proposed change and the final change.
 */
static int loongson2_cpufreq_target(struct cpufreq_policy *policy,
				     unsigned int index)
{
	unsigned int freq;

	freq =
	    ((cpu_clock_freq / 1000) *
	     loongson2_clockmod_table[index].driver_data) / 8;

	/* setting the cpu frequency */
	clk_set_rate(policy->clk, freq * 1000);

	return 0;
}

static int loongson2_cpufreq_cpu_init(struct cpufreq_policy *policy)
{
	struct clk *cpuclk;
	int i;
	unsigned long rate;
	int ret;

	cpuclk = clk_get(NULL, "cpu_clk");
	if (IS_ERR(cpuclk)) {
		pr_err("couldn't get CPU clk\n");
		return PTR_ERR(cpuclk);
	}

	rate = cpu_clock_freq / 1000;
	if (!rate) {
		clk_put(cpuclk);
		return -EINVAL;
	}

	/* clock table init */
	for (i = 2;
	     (loongson2_clockmod_table[i].frequency != CPUFREQ_TABLE_END);
	     i++)
		loongson2_clockmod_table[i].frequency = (rate * i) / 8;

	ret = clk_set_rate(cpuclk, rate * 1000);
	if (ret) {
		clk_put(cpuclk);
		return ret;
	}

	policy->clk = cpuclk;
	return cpufreq_generic_init(policy, &loongson2_clockmod_table[0], 0);
}

static int loongson2_cpufreq_exit(struct cpufreq_policy *policy)
{
	clk_put(policy->clk);
	return 0;
}

static struct cpufreq_driver loongson2_cpufreq_driver = {
	.name = "loongson2",
	.init = loongson2_cpufreq_cpu_init,
	.verify = cpufreq_generic_frequency_table_verify,
	.target_index = loongson2_cpufreq_target,
	.get = cpufreq_generic_get,
	.exit = loongson2_cpufreq_exit,
	.attr = cpufreq_generic_attr,
};

static struct platform_device_id platform_device_ids[] = {
	{
		.name = "loongson2_cpufreq",
	},
	{}
};

MODULE_DEVICE_TABLE(platform, platform_device_ids);

static struct platform_driver platform_driver = {
	.driver = {
		.name = "loongson2_cpufreq",
	},
	.id_table = platform_device_ids,
};

/*
 * This is the simple version of Loongson-2 wait, Maybe we need do this in
 * interrupt disabled context.
 */

static DEFINE_SPINLOCK(loongson2_wait_lock);

static void loongson2_cpu_wait(void)
{
	unsigned long flags;
	u32 cpu_freq;

	spin_lock_irqsave(&loongson2_wait_lock, flags);
	cpu_freq = LOONGSON_CHIPCFG(0);
	LOONGSON_CHIPCFG(0) &= ~0x7;	/* Put CPU into wait mode */
	LOONGSON_CHIPCFG(0) = cpu_freq;	/* Restore CPU state */
	spin_unlock_irqrestore(&loongson2_wait_lock, flags);
	local_irq_enable();
}

static int __init cpufreq_init(void)
{
	int ret;

	/* Register platform stuff */
	ret = platform_driver_register(&platform_driver);
	if (ret)
		return ret;

	pr_info("Loongson-2F CPU frequency driver\n");

	cpufreq_register_notifier(&loongson2_cpufreq_notifier_block,
				  CPUFREQ_TRANSITION_NOTIFIER);

	ret = cpufreq_register_driver(&loongson2_cpufreq_driver);

	if (!ret && !nowait) {
		saved_cpu_wait = cpu_wait;
		cpu_wait = loongson2_cpu_wait;
	}

	return ret;
}

static void __exit cpufreq_exit(void)
{
	if (!nowait && saved_cpu_wait)
		cpu_wait = saved_cpu_wait;
	cpufreq_unregister_driver(&loongson2_cpufreq_driver);
	cpufreq_unregister_notifier(&loongson2_cpufreq_notifier_block,
				    CPUFREQ_TRANSITION_NOTIFIER);

	platform_driver_unregister(&platform_driver);
}

module_init(cpufreq_init);
module_exit(cpufreq_exit);

module_param(nowait, uint, 0644);
MODULE_PARM_DESC(nowait, "Disable Loongson-2F specific wait");

MODULE_AUTHOR("Yanhua <yanh@lemote.com>");
MODULE_DESCRIPTION("cpufreq driver for Loongson2F");
MODULE_LICENSE("GPL");
Commit	Line	Data
f8ede0f7 WZ	1	/*
	2	* Cpufreq driver for the loongson-2 processors
	3	*
	4	* The 2E revision of loongson processor not support this feature.
	5	*
0bb383a2	6	* Copyright (C) 2006 - 2008 Lemote Inc. & Institute of Computing Technology
f8ede0f7 WZ	7	* Author: Yanhua, yanh@lemote.com
	8	*
	9	* This file is subject to the terms and conditions of the GNU General Public
	10	* License. See the file "COPYING" in the main directory of this archive
	11	* for more details.
	12	*/
1c5864e2 JP	13
	14	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
	15
f8ede0f7 WZ	16	#include <linux/cpufreq.h>
	17	#include <linux/module.h>
	18	#include <linux/err.h>
	19	#include <linux/sched.h> /* set_cpus_allowed() */
	20	#include <linux/delay.h>
	21	#include <linux/platform_device.h>
	22
	23	#include <asm/clock.h>
bdc92d74	24	#include <asm/idle.h>
f8ede0f7	25
9b2b6f7f	26	#include <asm/mach-loongson64/loongson.h>
f8ede0f7 WZ	27
	28	static uint nowait;
	29
f8ede0f7 WZ	30	static void (*saved_cpu_wait) (void);
	31
	32	static int loongson2_cpu_freq_notifier(struct notifier_block *nb,
	33	unsigned long val, void *data);
	34
	35	static struct notifier_block loongson2_cpufreq_notifier_block = {
	36	.notifier_call = loongson2_cpu_freq_notifier
	37	};
	38
	39	static int loongson2_cpu_freq_notifier(struct notifier_block *nb,
	40	unsigned long val, void *data)
	41	{
	42	if (val == CPUFREQ_POSTCHANGE)
	43	current_cpu_data.udelay_val = loops_per_jiffy;
	44
	45	return 0;
	46	}
	47
f8ede0f7 WZ	48	/*
	49	* Here we notify other drivers of the proposed change and the final change.
	50	*/
	51	static int loongson2_cpufreq_target(struct cpufreq_policy *policy,
9c0ebcf7	52	unsigned int index)
f8ede0f7	53	{
f8ede0f7 WZ	54	unsigned int freq;
f8ede0f7 WZ	55
f8ede0f7 WZ	56	freq =
f8ede0f7 WZ	57	((cpu_clock_freq / 1000) *
9c0ebcf7	58	loongson2_clockmod_table[index].driver_data) / 8;
f8ede0f7	59
f8ede0f7	60	/* setting the cpu frequency */
8e8acb32	61	clk_set_rate(policy->clk, freq * 1000);
f8ede0f7	62
f8ede0f7 WZ	63	return 0;
	64	}
	65
	66	static int loongson2_cpufreq_cpu_init(struct cpufreq_policy *policy)
	67	{
05ed6722	68	struct clk *cpuclk;
f8ede0f7	69	int i;
42913c79 JL	70	unsigned long rate;
42913c79 JL	71	int ret;
f8ede0f7	72
f8ede0f7 WZ	73	cpuclk = clk_get(NULL, "cpu_clk");
f8ede0f7 WZ	74	if (IS_ERR(cpuclk)) {
1c5864e2	75	pr_err("couldn't get CPU clk\n");
f8ede0f7 WZ	76	return PTR_ERR(cpuclk);
	77	}
	78
42913c79 JL	79	rate = cpu_clock_freq / 1000;
	80	if (!rate) {
	81	clk_put(cpuclk);
f8ede0f7	82	return -EINVAL;
42913c79	83	}
f8ede0f7 WZ	84
	85	/* clock table init */
	86	for (i = 2;
	87	(loongson2_clockmod_table[i].frequency != CPUFREQ_TABLE_END);
	88	i++)
42913c79	89	loongson2_clockmod_table[i].frequency = (rate * i) / 8;
f8ede0f7	90
8e8acb32	91	ret = clk_set_rate(cpuclk, rate * 1000);
f54fe64d AK	92	if (ret) {
	93	clk_put(cpuclk);
	94	return ret;
	95	}
	96
652ed95d	97	policy->clk = cpuclk;
e0b2da58	98	return cpufreq_generic_init(policy, &loongson2_clockmod_table[0], 0);
f8ede0f7 WZ	99	}
f8ede0f7 WZ	100
f8ede0f7 WZ	101	static int loongson2_cpufreq_exit(struct cpufreq_policy *policy)
f8ede0f7 WZ	102	{
652ed95d	103	clk_put(policy->clk);
f8ede0f7 WZ	104	return 0;
	105	}
	106
f8ede0f7	107	static struct cpufreq_driver loongson2_cpufreq_driver = {
f8ede0f7 WZ	108	.name = "loongson2",
f8ede0f7 WZ	109	.init = loongson2_cpufreq_cpu_init,
6b0f8d73	110	.verify = cpufreq_generic_frequency_table_verify,
9c0ebcf7	111	.target_index = loongson2_cpufreq_target,
652ed95d	112	.get = cpufreq_generic_get,
f8ede0f7	113	.exit = loongson2_cpufreq_exit,
6b0f8d73	114	.attr = cpufreq_generic_attr,
f8ede0f7 WZ	115	};
	116
	117	static struct platform_device_id platform_device_ids[] = {
	118	{
	119	.name = "loongson2_cpufreq",
	120	},
	121	{}
	122	};
	123
	124	MODULE_DEVICE_TABLE(platform, platform_device_ids);
	125
	126	static struct platform_driver platform_driver = {
	127	.driver = {
	128	.name = "loongson2_cpufreq",
f8ede0f7 WZ	129	},
	130	.id_table = platform_device_ids,
	131	};
	132
95cf1468 RB	133	/*
	134	* This is the simple version of Loongson-2 wait, Maybe we need do this in
	135	* interrupt disabled context.
	136	*/
	137
	138	static DEFINE_SPINLOCK(loongson2_wait_lock);
	139
	140	static void loongson2_cpu_wait(void)
	141	{
	142	unsigned long flags;
	143	u32 cpu_freq;
	144
	145	spin_lock_irqsave(&loongson2_wait_lock, flags);
140e39c1 HC	146	cpu_freq = LOONGSON_CHIPCFG(0);
	147	LOONGSON_CHIPCFG(0) &= ~0x7; /* Put CPU into wait mode */
	148	LOONGSON_CHIPCFG(0) = cpu_freq; /* Restore CPU state */
95cf1468	149	spin_unlock_irqrestore(&loongson2_wait_lock, flags);
fb40bc3e	150	local_irq_enable();
95cf1468 RB	151	}
95cf1468 RB	152
f8ede0f7 WZ	153	static int __init cpufreq_init(void)
	154	{
	155	int ret;
	156
	157	/* Register platform stuff */
	158	ret = platform_driver_register(&platform_driver);
	159	if (ret)
	160	return ret;
	161
1c5864e2	162	pr_info("Loongson-2F CPU frequency driver\n");
f8ede0f7 WZ	163
	164	cpufreq_register_notifier(&loongson2_cpufreq_notifier_block,
	165	CPUFREQ_TRANSITION_NOTIFIER);
	166
	167	ret = cpufreq_register_driver(&loongson2_cpufreq_driver);
	168
	169	if (!ret && !nowait) {
	170	saved_cpu_wait = cpu_wait;
	171	cpu_wait = loongson2_cpu_wait;
	172	}
	173
	174	return ret;
	175	}
	176
	177	static void __exit cpufreq_exit(void)
	178	{
	179	if (!nowait && saved_cpu_wait)
	180	cpu_wait = saved_cpu_wait;
	181	cpufreq_unregister_driver(&loongson2_cpufreq_driver);
	182	cpufreq_unregister_notifier(&loongson2_cpufreq_notifier_block,
	183	CPUFREQ_TRANSITION_NOTIFIER);
	184
	185	platform_driver_unregister(&platform_driver);
	186	}
	187
	188	module_init(cpufreq_init);
	189	module_exit(cpufreq_exit);
	190
	191	module_param(nowait, uint, 0644);
	192	MODULE_PARM_DESC(nowait, "Disable Loongson-2F specific wait");
	193
	194	MODULE_AUTHOR("Yanhua <yanh@lemote.com>");
	195	MODULE_DESCRIPTION("cpufreq driver for Loongson2F");
	196	MODULE_LICENSE("GPL");