[mirror_ubuntu-bionic-kernel.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/cpufreq.h>
#include <linux/device.h>
#include <linux/export.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/pm_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 = of_cpu_device_node_get(cpu);

	if (!of_get_property(np, "operating-points", NULL)) {
		of_node_put(np);
		np = NULL;
	}

	return np;
}

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

	np = of_node_get(cpu_dev->of_node);
	if (!np) {
		pr_err("failed to find cpu%d node\n", cpu_dev->id);
		return -ENOENT;
	}

	ret = dev_pm_opp_of_add_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 = of_node_get(cpu_dev->of_node);
	if (!np) {
		pr_info("Failed to find cpu node. Use CPUFREQ_ETERNAL transition latency\n");
		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,
	.free_opp_table = dev_pm_opp_of_remove_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",
	},
	.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 v2");
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
	22	#include <linux/cpufreq.h>
	23	#include <linux/device.h>
	24	#include <linux/export.h>
	25	#include <linux/module.h>
da0eb143	26	#include <linux/of_device.h>
e4db1c74	27	#include <linux/pm_opp.h>
9076eaca	28	#include <linux/platform_device.h>
8a67f0ef VK	29	#include <linux/slab.h>
	30	#include <linux/types.h>
	31	#include "arm_big_little.h"
	32
92a9b5c2 VK	33	/* get cpu node with valid operating-points */
92a9b5c2 VK	34	static struct device_node *get_cpu_node_with_valid_op(int cpu)
8a67f0ef	35	{
da0eb143	36	struct device_node *np = of_cpu_device_node_get(cpu);
8a67f0ef	37
da0eb143 SH	38	if (!of_get_property(np, "operating-points", NULL)) {
	39	of_node_put(np);
	40	np = NULL;
763f8c3f VK	41	}
763f8c3f VK	42
92a9b5c2 VK	43	return np;
	44	}
	45
	46	static int dt_init_opp_table(struct device *cpu_dev)
	47	{
	48	struct device_node *np;
	49	int ret;
	50
da0eb143 SH	51	np = of_node_get(cpu_dev->of_node);
	52	if (!np) {
	53	pr_err("failed to find cpu%d node\n", cpu_dev->id);
	54	return -ENOENT;
	55	}
92a9b5c2	56
8f8d37b2	57	ret = dev_pm_opp_of_add_table(cpu_dev);
92a9b5c2 VK	58	of_node_put(np);
	59
	60	return ret;
8a67f0ef VK	61	}
	62
	63	static int dt_get_transition_latency(struct device *cpu_dev)
	64	{
92a9b5c2	65	struct device_node *np;
8a67f0ef	66	u32 transition_latency = CPUFREQ_ETERNAL;
8a67f0ef	67
da0eb143 SH	68	np = of_node_get(cpu_dev->of_node);
	69	if (!np) {
	70	pr_info("Failed to find cpu node. Use CPUFREQ_ETERNAL transition latency\n");
3c792e0f	71	return CPUFREQ_ETERNAL;
da0eb143	72	}
763f8c3f	73
92a9b5c2 VK	74	of_property_read_u32(np, "clock-latency", &transition_latency);
92a9b5c2 VK	75	of_node_put(np);
8a67f0ef	76
92a9b5c2 VK	77	pr_debug("%s: clock-latency: %d\n", __func__, transition_latency);
92a9b5c2 VK	78	return transition_latency;
8a67f0ef VK	79	}
	80
	81	static struct cpufreq_arm_bL_ops dt_bL_ops = {
	82	.name = "dt-bl",
	83	.get_transition_latency = dt_get_transition_latency,
	84	.init_opp_table = dt_init_opp_table,
8f8d37b2	85	.free_opp_table = dev_pm_opp_of_remove_table,
8a67f0ef VK	86	};
8a67f0ef VK	87
9076eaca	88	static int generic_bL_probe(struct platform_device *pdev)
8a67f0ef	89	{
92a9b5c2 VK	90	struct device_node *np;
	91
	92	np = get_cpu_node_with_valid_op(0);
	93	if (!np)
	94	return -ENODEV;
	95
	96	of_node_put(np);
8a67f0ef VK	97	return bL_cpufreq_register(&dt_bL_ops);
8a67f0ef VK	98	}
8a67f0ef	99
9076eaca	100	static int generic_bL_remove(struct platform_device *pdev)
8a67f0ef	101	{
9076eaca VK	102	bL_cpufreq_unregister(&dt_bL_ops);
9076eaca VK	103	return 0;
8a67f0ef	104	}
9076eaca VK	105
	106	static struct platform_driver generic_bL_platdrv = {
	107	.driver = {
	108	.name = "arm-bL-cpufreq-dt",
9076eaca VK	109	},
	110	.probe = generic_bL_probe,
	111	.remove = generic_bL_remove,
	112	};
	113	module_platform_driver(generic_bL_platdrv);
8a67f0ef VK	114
	115	MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>");
	116	MODULE_DESCRIPTION("Generic ARM big LITTLE cpufreq driver via DT");
39c8bbaf	117	MODULE_LICENSE("GPL v2");