| /* |
| * 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 |
| * |
| * 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. |
| */ |
| |
| #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. |
| */ |
| int ucv2_verify_speed(struct cpufreq_policy *policy) |
| { |
| if (policy->cpu) |
| return -EINVAL; |
| |
| cpufreq_verify_within_limits(policy, |
| policy->cpuinfo.min_freq, policy->cpuinfo.max_freq); |
| |
| return 0; |
| } |
| |
| static unsigned int ucv2_getspeed(unsigned int cpu) |
| { |
| struct clk *mclk = clk_get(NULL, "MAIN_CLK"); |
| |
| if (cpu) |
| return 0; |
| return clk_get_rate(mclk)/1000; |
| } |
| |
| static int ucv2_target(struct cpufreq_policy *policy, |
| unsigned int target_freq, |
| unsigned int relation) |
| { |
| unsigned int cur = ucv2_getspeed(0); |
| struct cpufreq_freqs freqs; |
| struct clk *mclk = clk_get(NULL, "MAIN_CLK"); |
| |
| cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE); |
| |
| if (!clk_set_rate(mclk, target_freq * 1000)) { |
| freqs.old = cur; |
| freqs.new = target_freq; |
| } |
| |
| cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE); |
| |
| return 0; |
| } |
| |
| static int __init ucv2_cpu_init(struct cpufreq_policy *policy) |
| { |
| if (policy->cpu != 0) |
| return -EINVAL; |
| policy->cur = ucv2_getspeed(0); |
| policy->min = policy->cpuinfo.min_freq = 250000; |
| policy->max = policy->cpuinfo.max_freq = 1000000; |
| policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL; |
| return 0; |
| } |
| |
| static struct cpufreq_driver ucv2_driver = { |
| .flags = CPUFREQ_STICKY, |
| .verify = ucv2_verify_speed, |
| .target = ucv2_target, |
| .get = ucv2_getspeed, |
| .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); |
