[GitHub/LineageOS/android_kernel_samsung_universal7580.git] / drivers / cpufreq / arm_big_little_dt.c

/*
 * Generic big.LITTLE CPUFreq Interface driver
 *
 * It provides necessary ops to arm_big_little cpufreq driver and gets
 * Frequency information from Device Tree. Freq table in DT must be in KHz.
 *
 * Copyright (C) 2013 Linaro.
 * Viresh Kumar <viresh.kumar@linaro.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
 * kind, whether express or implied; without even the implied warranty
 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/cpu.h>
#include <linux/cpufreq.h>
#include <linux/device.h>
#include <linux/export.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/opp.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/types.h>
#include "arm_big_little.h"

/* get cpu node with valid operating-points */
static struct device_node *get_cpu_node_with_valid_op(int cpu)
{
	struct device_node *np = NULL, *parent;
	int count = 0;

	parent = of_find_node_by_path("/cpus");
	if (!parent) {
		pr_err("failed to find OF /cpus\n");
		return NULL;
	}

	for_each_child_of_node(parent, np) {
		if (count++ != cpu)
			continue;
		if (!of_get_property(np, "operating-points", NULL)) {
			of_node_put(np);
			np = NULL;
		}

		break;
	}

	of_node_put(parent);
	return np;
}

static int dt_init_opp_table(struct device *cpu_dev)
{
	struct device_node *np;
	int ret;

	np = get_cpu_node_with_valid_op(cpu_dev->id);
	if (!np)
		return -ENODATA;

	cpu_dev->of_node = np;
	ret = of_init_opp_table(cpu_dev);
	of_node_put(np);

	return ret;
}

static int dt_get_transition_latency(struct device *cpu_dev)
{
	struct device_node *np;
	u32 transition_latency = CPUFREQ_ETERNAL;

	np = get_cpu_node_with_valid_op(cpu_dev->id);
	if (!np)
		return CPUFREQ_ETERNAL;

	of_property_read_u32(np, "clock-latency", &transition_latency);
	of_node_put(np);

	pr_debug("%s: clock-latency: %d\n", __func__, transition_latency);
	return transition_latency;
}

static struct cpufreq_arm_bL_ops dt_bL_ops = {
	.name	= "dt-bl",
	.get_transition_latency = dt_get_transition_latency,
	.init_opp_table = dt_init_opp_table,
};

static int generic_bL_probe(struct platform_device *pdev)
{
	struct device_node *np;

	np = get_cpu_node_with_valid_op(0);
	if (!np)
		return -ENODEV;

	of_node_put(np);
	return bL_cpufreq_register(&dt_bL_ops);
}

static int generic_bL_remove(struct platform_device *pdev)
{
	bL_cpufreq_unregister(&dt_bL_ops);
	return 0;
}

static struct platform_driver generic_bL_platdrv = {
	.driver = {
		.name	= "arm-bL-cpufreq-dt",
		.owner	= THIS_MODULE,
	},
	.probe		= generic_bL_probe,
	.remove		= generic_bL_remove,
};
module_platform_driver(generic_bL_platdrv);

MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>");
MODULE_DESCRIPTION("Generic ARM big LITTLE cpufreq driver via DT");
MODULE_LICENSE("GPL");
Commit	Line	Data
8a67f0ef VK	1	/*
	2	* Generic big.LITTLE CPUFreq Interface driver
	3	*
	4	* It provides necessary ops to arm_big_little cpufreq driver and gets
	5	* Frequency information from Device Tree. Freq table in DT must be in KHz.
	6	*
	7	* Copyright (C) 2013 Linaro.
	8	* Viresh Kumar <viresh.kumar@linaro.org>
	9	*
	10	* This program is free software; you can redistribute it and/or modify
	11	* it under the terms of the GNU General Public License version 2 as
	12	* published by the Free Software Foundation.
	13	*
	14	* This program is distributed "as is" WITHOUT ANY WARRANTY of any
	15	* kind, whether express or implied; without even the implied warranty
	16	* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	17	* GNU General Public License for more details.
	18	*/
	19
	20	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
	21
92a9b5c2	22	#include <linux/cpu.h>
8a67f0ef VK	23	#include <linux/cpufreq.h>
	24	#include <linux/device.h>
	25	#include <linux/export.h>
	26	#include <linux/module.h>
	27	#include <linux/of.h>
	28	#include <linux/opp.h>
9076eaca	29	#include <linux/platform_device.h>
8a67f0ef VK	30	#include <linux/slab.h>
	31	#include <linux/types.h>
	32	#include "arm_big_little.h"
	33
92a9b5c2 VK	34	/* get cpu node with valid operating-points */
92a9b5c2 VK	35	static struct device_node *get_cpu_node_with_valid_op(int cpu)
8a67f0ef	36	{
92a9b5c2 VK	37	struct device_node np = NULL, parent;
92a9b5c2 VK	38	int count = 0;
8a67f0ef	39
763f8c3f VK	40	parent = of_find_node_by_path("/cpus");
	41	if (!parent) {
	42	pr_err("failed to find OF /cpus\n");
92a9b5c2	43	return NULL;
763f8c3f VK	44	}
	45
	46	for_each_child_of_node(parent, np) {
92a9b5c2	47	if (count++ != cpu)
8a67f0ef	48	continue;
763f8c3f	49	if (!of_get_property(np, "operating-points", NULL)) {
92a9b5c2 VK	50	of_node_put(np);
92a9b5c2 VK	51	np = NULL;
763f8c3f	52	}
763f8c3f	53
92a9b5c2	54	break;
8a67f0ef VK	55	}
8a67f0ef VK	56
92a9b5c2 VK	57	of_node_put(parent);
	58	return np;
	59	}
	60
	61	static int dt_init_opp_table(struct device *cpu_dev)
	62	{
	63	struct device_node *np;
	64	int ret;
	65
	66	np = get_cpu_node_with_valid_op(cpu_dev->id);
	67	if (!np)
	68	return -ENODATA;
	69
	70	cpu_dev->of_node = np;
	71	ret = of_init_opp_table(cpu_dev);
	72	of_node_put(np);
	73
	74	return ret;
8a67f0ef VK	75	}
	76
	77	static int dt_get_transition_latency(struct device *cpu_dev)
	78	{
92a9b5c2	79	struct device_node *np;
8a67f0ef	80	u32 transition_latency = CPUFREQ_ETERNAL;
8a67f0ef	81
92a9b5c2 VK	82	np = get_cpu_node_with_valid_op(cpu_dev->id);
92a9b5c2 VK	83	if (!np)
3c792e0f	84	return CPUFREQ_ETERNAL;
763f8c3f	85
92a9b5c2 VK	86	of_property_read_u32(np, "clock-latency", &transition_latency);
92a9b5c2 VK	87	of_node_put(np);
8a67f0ef	88
92a9b5c2 VK	89	pr_debug("%s: clock-latency: %d\n", __func__, transition_latency);
92a9b5c2 VK	90	return transition_latency;
8a67f0ef VK	91	}
	92
	93	static struct cpufreq_arm_bL_ops dt_bL_ops = {
	94	.name = "dt-bl",
	95	.get_transition_latency = dt_get_transition_latency,
	96	.init_opp_table = dt_init_opp_table,
	97	};
	98
9076eaca	99	static int generic_bL_probe(struct platform_device *pdev)
8a67f0ef	100	{
92a9b5c2 VK	101	struct device_node *np;
	102
	103	np = get_cpu_node_with_valid_op(0);
	104	if (!np)
	105	return -ENODEV;
	106
	107	of_node_put(np);
8a67f0ef VK	108	return bL_cpufreq_register(&dt_bL_ops);
8a67f0ef VK	109	}
8a67f0ef	110
9076eaca	111	static int generic_bL_remove(struct platform_device *pdev)
8a67f0ef	112	{
9076eaca VK	113	bL_cpufreq_unregister(&dt_bL_ops);
9076eaca VK	114	return 0;
8a67f0ef	115	}
9076eaca VK	116
	117	static struct platform_driver generic_bL_platdrv = {
	118	.driver = {
	119	.name = "arm-bL-cpufreq-dt",
	120	.owner = THIS_MODULE,
	121	},
	122	.probe = generic_bL_probe,
	123	.remove = generic_bL_remove,
	124	};
	125	module_platform_driver(generic_bL_platdrv);
8a67f0ef VK	126
	127	MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>");
	128	MODULE_DESCRIPTION("Generic ARM big LITTLE cpufreq driver via DT");
	129	MODULE_LICENSE("GPL");