forked from luck/tmp_suning_uos_patched
47ac9aa165
The TC2(i.e. CA15_A7) Versatile Express has external Cortex M3 based power controller which is responsible for CPU DVFS and SPC provides the interface for the same. This patch adds a tiny interface driver to check if OPPs are initialised by SPC platform code and register the arm_big_little cpufreq driver. Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
71 lines
1.9 KiB
C
71 lines
1.9 KiB
C
/*
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* Versatile Express SPC CPUFreq Interface driver
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*
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* It provides necessary ops to arm_big_little cpufreq driver.
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*
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* Copyright (C) 2013 ARM Ltd.
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* Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed "as is" WITHOUT ANY WARRANTY of any
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* kind, whether express or implied; without even the implied warranty
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* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/cpufreq.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/pm_opp.h>
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#include <linux/types.h>
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#include "arm_big_little.h"
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static int ve_spc_init_opp_table(struct device *cpu_dev)
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{
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/*
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* platform specific SPC code must initialise the opp table
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* so just check if the OPP count is non-zero
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*/
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return dev_pm_opp_get_opp_count(cpu_dev) <= 0;
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}
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static int ve_spc_get_transition_latency(struct device *cpu_dev)
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{
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return 1000000; /* 1 ms */
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}
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static struct cpufreq_arm_bL_ops ve_spc_cpufreq_ops = {
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.name = "vexpress-spc",
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.get_transition_latency = ve_spc_get_transition_latency,
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.init_opp_table = ve_spc_init_opp_table,
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};
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static int ve_spc_cpufreq_probe(struct platform_device *pdev)
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{
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return bL_cpufreq_register(&ve_spc_cpufreq_ops);
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}
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static int ve_spc_cpufreq_remove(struct platform_device *pdev)
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{
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bL_cpufreq_unregister(&ve_spc_cpufreq_ops);
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return 0;
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}
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static struct platform_driver ve_spc_cpufreq_platdrv = {
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.driver = {
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.name = "vexpress-spc-cpufreq",
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.owner = THIS_MODULE,
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},
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.probe = ve_spc_cpufreq_probe,
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.remove = ve_spc_cpufreq_remove,
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};
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module_platform_driver(ve_spc_cpufreq_platdrv);
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MODULE_LICENSE("GPL");
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