| /* |
| * 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 = { |
| .name = "vexpress-spc-cpufreq", |
| }, |
| .probe = ve_spc_cpufreq_probe, |
| .remove = ve_spc_cpufreq_remove, |
| }; |
| module_platform_driver(ve_spc_cpufreq_platdrv); |
| |
| MODULE_LICENSE("GPL"); |