linux-imx

/*

 * Versatile Express SPC CPUFreq Interface driver

 *

 * It provides necessary ops to arm_big_little cpufreq driver.

 *

 * Copyright (C) 2013 ARM Ltd.

 * Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>

 *

 * 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/module.h>

#include <linux/platform_device.h>

#include <linux/pm_opp.h>

#include <linux/types.h>

​

#include "arm_big_little.h"

​

static int ve_spc_init_opp_table(const struct cpumask *cpumask)

{

    struct device *cpu_dev = get_cpu_device(cpumask_first(cpumask));

    /*

     * platform specific SPC code must initialise the opp table

     * so just check if the OPP count is non-zero

     */

    return dev_pm_opp_get_opp_count(cpu_dev) <= 0;

}

​

static int ve_spc_get_transition_latency(struct device *cpu_dev)

{

    return 1000000; /* 1 ms */

}

​

static const struct cpufreq_arm_bL_ops ve_spc_cpufreq_ops = {

    .name   = "vexpress-spc",

    .get_transition_latency = ve_spc_get_transition_latency,

    .init_opp_table = ve_spc_init_opp_table,

};

​

static int ve_spc_cpufreq_probe(struct platform_device *pdev)

{

    return bL_cpufreq_register(&ve_spc_cpufreq_ops);

}

​

static int ve_spc_cpufreq_remove(struct platform_device *pdev)

{

    bL_cpufreq_unregister(&ve_spc_cpufreq_ops);

    return 0;

}

​

static struct platform_driver ve_spc_cpufreq_platdrv = {

    .driver = {