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Release 4.14 drivers/cpufreq/at32ap-cpufreq.c

Directory: drivers/cpufreq
/*
 * Copyright (C) 2004-2007 Atmel Corporation
 *
 * Based on MIPS implementation arch/mips/kernel/time.c
 *   Copyright 2001 MontaVista Software Inc.
 *
 * 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.
 */

/*#define DEBUG*/

#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/cpufreq.h>
#include <linux/io.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/export.h>
#include <linux/slab.h>


static struct cpufreq_frequency_table *freq_table;


static unsigned int	ref_freq;

static unsigned long	loops_per_jiffy_ref;


static int at32_set_target(struct cpufreq_policy *policy, unsigned int index) { unsigned int old_freq, new_freq; old_freq = policy->cur; new_freq = freq_table[index].frequency; if (!ref_freq) { ref_freq = old_freq; loops_per_jiffy_ref = boot_cpu_data.loops_per_jiffy; } if (old_freq < new_freq) boot_cpu_data.loops_per_jiffy = cpufreq_scale( loops_per_jiffy_ref, ref_freq, new_freq); clk_set_rate(policy->clk, new_freq * 1000); if (new_freq < old_freq) boot_cpu_data.loops_per_jiffy = cpufreq_scale( loops_per_jiffy_ref, ref_freq, new_freq); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Håvard Skinnemoen4643.81%120.00%
Hans-Christian Noren Egtvedt3028.57%120.00%
Viresh Kumar2927.62%360.00%
Total105100.00%5100.00%


static int at32_cpufreq_driver_init(struct cpufreq_policy *policy) { unsigned int frequency, rate, min_freq; struct clk *cpuclk; int retval, steps, i; if (policy->cpu != 0) return -EINVAL; cpuclk = clk_get(NULL, "cpu"); if (IS_ERR(cpuclk)) { pr_debug("cpufreq: could not get CPU clk\n"); retval = PTR_ERR(cpuclk); goto out_err; } min_freq = (clk_round_rate(cpuclk, 1) + 500) / 1000; frequency = (clk_round_rate(cpuclk, ~0UL) + 500) / 1000; policy->cpuinfo.transition_latency = 0; /* * AVR32 CPU frequency rate scales in power of two between maximum and * minimum, also add space for the table end marker. * * Further validate that the frequency is usable, and append it to the * frequency table. */ steps = fls(frequency / min_freq) + 1; freq_table = kzalloc(steps * sizeof(struct cpufreq_frequency_table), GFP_KERNEL); if (!freq_table) { retval = -ENOMEM; goto out_err_put_clk; } for (i = 0; i < (steps - 1); i++) { rate = clk_round_rate(cpuclk, frequency * 1000) / 1000; if (rate != frequency) freq_table[i].frequency = CPUFREQ_ENTRY_INVALID; else freq_table[i].frequency = frequency; frequency /= 2; } policy->clk = cpuclk; freq_table[steps - 1].frequency = CPUFREQ_TABLE_END; retval = cpufreq_table_validate_and_show(policy, freq_table); if (!retval) { printk("cpufreq: AT32AP CPU frequency driver\n"); return 0; } kfree(freq_table); out_err_put_clk: clk_put(cpuclk); out_err: return retval; }

Contributors

PersonTokensPropCommitsCommitProp
Hans-Christian Noren Egtvedt26194.57%250.00%
Viresh Kumar155.43%250.00%
Total276100.00%4100.00%

static struct cpufreq_driver at32_driver = { .name = "at32ap", .init = at32_cpufreq_driver_init, .verify = cpufreq_generic_frequency_table_verify, .target_index = at32_set_target, .get = cpufreq_generic_get, .flags = CPUFREQ_STICKY, };
static int __init at32_cpufreq_init(void) { return cpufreq_register_driver(&at32_driver); }

Contributors

PersonTokensPropCommitsCommitProp
Hans-Christian Noren Egtvedt16100.00%1100.00%
Total16100.00%1100.00%

late_initcall(at32_cpufreq_init);

Overall Contributors

PersonTokensPropCommitsCommitProp
Hans-Christian Noren Egtvedt37978.31%220.00%
Håvard Skinnemoen5711.78%220.00%
Viresh Kumar479.71%550.00%
Paul Gortmaker10.21%110.00%
Total484100.00%10100.00%
Directory: drivers/cpufreq
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