| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * clock scaling for the UniCore-II |
| * |
| * Code specific to PKUnity SoC and UniCore ISA |
| * |
| * Maintained by GUAN Xue-tao <gxt@mprc.pku.edu.cn> |
| * Copyright (C) 2001-2010 Guan Xuetao |
| */ |
| |
| #include <linux/err.h> |
| #include <linux/kernel.h> |
| #include <linux/types.h> |
| #include <linux/init.h> |
| #include <linux/clk.h> |
| #include <linux/cpufreq.h> |
| |
| #include <mach/hardware.h> |
| |
| static struct cpufreq_driver ucv2_driver; |
| |
| /* make sure that only the "userspace" governor is run |
| * -- anything else wouldn't make sense on this platform, anyway. |
| */ |
| static int ucv2_verify_speed(struct cpufreq_policy *policy) |
| { |
| if (policy->cpu) |
| return -EINVAL; |
| |
| cpufreq_verify_within_cpu_limits(policy); |
| return 0; |
| } |
| |
| static int ucv2_target(struct cpufreq_policy *policy, |
| unsigned int target_freq, |
| unsigned int relation) |
| { |
| struct cpufreq_freqs freqs; |
| int ret; |
| |
| freqs.old = policy->cur; |
| freqs.new = target_freq; |
| |
| cpufreq_freq_transition_begin(policy, &freqs); |
| ret = clk_set_rate(policy->clk, target_freq * 1000); |
| cpufreq_freq_transition_end(policy, &freqs, ret); |
| |
| return ret; |
| } |
| |
| static int __init ucv2_cpu_init(struct cpufreq_policy *policy) |
| { |
| if (policy->cpu != 0) |
| return -EINVAL; |
| |
| policy->min = policy->cpuinfo.min_freq = 250000; |
| policy->max = policy->cpuinfo.max_freq = 1000000; |
| policy->clk = clk_get(NULL, "MAIN_CLK"); |
| return PTR_ERR_OR_ZERO(policy->clk); |
| } |
| |
| static struct cpufreq_driver ucv2_driver = { |
| .flags = CPUFREQ_STICKY | CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING, |
| .verify = ucv2_verify_speed, |
| .target = ucv2_target, |
| .get = cpufreq_generic_get, |
| .init = ucv2_cpu_init, |
| .name = "UniCore-II", |
| }; |
| |
| static int __init ucv2_cpufreq_init(void) |
| { |
| return cpufreq_register_driver(&ucv2_driver); |
| } |
| |
| arch_initcall(ucv2_cpufreq_init); |