[mirror_ubuntu-zesty-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_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 = dev_pm_opp_of_cpumask_add_table,
	.free_opp_table = dev_pm_opp_of_cpumask_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
8a67f0ef VK	46	static int dt_get_transition_latency(struct device *cpu_dev)
8a67f0ef VK	47	{
92a9b5c2	48	struct device_node *np;
8a67f0ef	49	u32 transition_latency = CPUFREQ_ETERNAL;
8a67f0ef	50
da0eb143 SH	51	np = of_node_get(cpu_dev->of_node);
	52	if (!np) {
	53	pr_info("Failed to find cpu node. Use CPUFREQ_ETERNAL transition latency\n");
3c792e0f	54	return CPUFREQ_ETERNAL;
da0eb143	55	}
763f8c3f	56
92a9b5c2 VK	57	of_property_read_u32(np, "clock-latency", &transition_latency);
92a9b5c2 VK	58	of_node_put(np);
8a67f0ef	59
92a9b5c2 VK	60	pr_debug("%s: clock-latency: %d\n", __func__, transition_latency);
92a9b5c2 VK	61	return transition_latency;
8a67f0ef VK	62	}
	63
	64	static struct cpufreq_arm_bL_ops dt_bL_ops = {
	65	.name = "dt-bl",
	66	.get_transition_latency = dt_get_transition_latency,
d9975b0b SH	67	.init_opp_table = dev_pm_opp_of_cpumask_add_table,
d9975b0b SH	68	.free_opp_table = dev_pm_opp_of_cpumask_remove_table,
8a67f0ef VK	69	};
8a67f0ef VK	70
9076eaca	71	static int generic_bL_probe(struct platform_device *pdev)
8a67f0ef	72	{
92a9b5c2 VK	73	struct device_node *np;
	74
	75	np = get_cpu_node_with_valid_op(0);
	76	if (!np)
	77	return -ENODEV;
	78
	79	of_node_put(np);
8a67f0ef VK	80	return bL_cpufreq_register(&dt_bL_ops);
8a67f0ef VK	81	}
8a67f0ef	82
9076eaca	83	static int generic_bL_remove(struct platform_device *pdev)
8a67f0ef	84	{
9076eaca VK	85	bL_cpufreq_unregister(&dt_bL_ops);
9076eaca VK	86	return 0;
8a67f0ef	87	}
9076eaca VK	88
	89	static struct platform_driver generic_bL_platdrv = {
	90	.driver = {
	91	.name = "arm-bL-cpufreq-dt",
9076eaca VK	92	},
	93	.probe = generic_bL_probe,
	94	.remove = generic_bL_remove,
	95	};
	96	module_platform_driver(generic_bL_platdrv);
8a67f0ef VK	97
	98	MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>");
	99	MODULE_DESCRIPTION("Generic ARM big LITTLE cpufreq driver via DT");
39c8bbaf	100	MODULE_LICENSE("GPL v2");