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Viewing changes to drivers/cpufreq/db8500-cpufreq.c

  • Committer: Bazaar Package Importer
  • Author(s): Paolo Pisati
  • Date: 2011-06-29 15:23:51 UTC
  • mfrom: (26.1.1 natty-proposed)
  • Revision ID: james.westby@ubuntu.com-20110629152351-xs96tm303d95rpbk
Tags: 3.0.0-1200.2
* Rebased against 3.0.0-6.7
* BSP from TI based on 3.0.0

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drivers/cpufreq/db8500-cpufreq.c
 
1
/*
 
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 * Copyright (C) STMicroelectronics 2009
 
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 * Copyright (C) ST-Ericsson SA 2010
 
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 *
 
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 * License Terms: GNU General Public License v2
 
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 * Author: Sundar Iyer <sundar.iyer@stericsson.com>
 
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 * Author: Martin Persson <martin.persson@stericsson.com>
 
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 * Author: Jonas Aaberg <jonas.aberg@stericsson.com>
 
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 *
 
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 */
 
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#include <linux/kernel.h>
 
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#include <linux/cpufreq.h>
 
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#include <linux/delay.h>
 
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#include <linux/slab.h>
 
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#include <linux/mfd/db8500-prcmu.h>
 
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#include <mach/id.h>
 
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static struct cpufreq_frequency_table freq_table[] = {
 
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        [0] = {
 
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                .index = 0,
 
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                .frequency = 300000,
 
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        },
 
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        [1] = {
 
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                .index = 1,
 
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                .frequency = 600000,
 
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        },
 
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        [2] = {
 
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                /* Used for MAX_OPP, if available */
 
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                .index = 2,
 
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                .frequency = CPUFREQ_TABLE_END,
 
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        },
 
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        [3] = {
 
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                .index = 3,
 
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                .frequency = CPUFREQ_TABLE_END,
 
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        },
 
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};
 
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static enum arm_opp idx2opp[] = {
 
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        ARM_50_OPP,
 
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        ARM_100_OPP,
 
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        ARM_MAX_OPP
 
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};
 
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static struct freq_attr *db8500_cpufreq_attr[] = {
 
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        &cpufreq_freq_attr_scaling_available_freqs,
 
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        NULL,
 
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};
 
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static int db8500_cpufreq_verify_speed(struct cpufreq_policy *policy)
 
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{
 
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        return cpufreq_frequency_table_verify(policy, freq_table);
 
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}
 
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static int db8500_cpufreq_target(struct cpufreq_policy *policy,
 
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                                unsigned int target_freq,
 
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                                unsigned int relation)
 
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{
 
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        struct cpufreq_freqs freqs;
 
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        unsigned int idx;
 
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        /* scale the target frequency to one of the extremes supported */
 
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        if (target_freq < policy->cpuinfo.min_freq)
 
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                target_freq = policy->cpuinfo.min_freq;
 
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        if (target_freq > policy->cpuinfo.max_freq)
 
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                target_freq = policy->cpuinfo.max_freq;
 
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        /* Lookup the next frequency */
 
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        if (cpufreq_frequency_table_target
 
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            (policy, freq_table, target_freq, relation, &idx)) {
 
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                return -EINVAL;
 
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        }
 
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        freqs.old = policy->cur;
 
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        freqs.new = freq_table[idx].frequency;
 
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        freqs.cpu = policy->cpu;
 
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        if (freqs.old == freqs.new)
 
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                return 0;
 
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        /* pre-change notification */
 
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        cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
 
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        /* request the PRCM unit for opp change */
 
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        if (prcmu_set_arm_opp(idx2opp[idx])) {
 
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                pr_err("db8500-cpufreq:  Failed to set OPP level\n");
 
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                return -EINVAL;
 
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        }
 
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        /* post change notification */
 
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        cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
 
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        return 0;
 
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}
 
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static unsigned int db8500_cpufreq_getspeed(unsigned int cpu)
 
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{
 
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        int i;
 
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        /* request the prcm to get the current ARM opp */
 
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        for (i = 0; prcmu_get_arm_opp() != idx2opp[i]; i++)
 
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                ;
 
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        return freq_table[i].frequency;
 
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}
 
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static int __cpuinit db8500_cpufreq_init(struct cpufreq_policy *policy)
 
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{
 
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        int res;
 
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        int i;
 
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        BUILD_BUG_ON(ARRAY_SIZE(idx2opp) + 1 != ARRAY_SIZE(freq_table));
 
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        if (cpu_is_u8500v2() && !prcmu_is_u8400()) {
 
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                freq_table[0].frequency = 400000;
 
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                freq_table[1].frequency = 800000;
 
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                if (prcmu_has_arm_maxopp())
 
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                        freq_table[2].frequency = 1000000;
 
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        }
 
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        /* get policy fields based on the table */
 
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        res = cpufreq_frequency_table_cpuinfo(policy, freq_table);
 
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        if (!res)
 
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                cpufreq_frequency_table_get_attr(freq_table, policy->cpu);
 
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        else {
 
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                pr_err("db8500-cpufreq : Failed to read policy table\n");
 
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                return res;
 
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        }
 
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        policy->min = policy->cpuinfo.min_freq;
 
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        policy->max = policy->cpuinfo.max_freq;
 
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        policy->cur = db8500_cpufreq_getspeed(policy->cpu);
 
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        for (i = 0; freq_table[i].frequency != policy->cur; i++)
 
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                ;
 
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        policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
 
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        /*
 
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         * FIXME : Need to take time measurement across the target()
 
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         *         function with no/some/all drivers in the notification
 
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         *         list.
 
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         */
 
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        policy->cpuinfo.transition_latency = 20 * 1000; /* in ns */
 
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        /* policy sharing between dual CPUs */
 
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        cpumask_copy(policy->cpus, &cpu_present_map);
 
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        policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;
 
147
 
 
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        return 0;
 
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}
 
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151
static struct cpufreq_driver db8500_cpufreq_driver = {
 
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        .flags  = CPUFREQ_STICKY,
 
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        .verify = db8500_cpufreq_verify_speed,
 
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        .target = db8500_cpufreq_target,
 
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        .get    = db8500_cpufreq_getspeed,
 
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        .init   = db8500_cpufreq_init,
 
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        .name   = "DB8500",
 
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        .attr   = db8500_cpufreq_attr,
 
159
};
 
160
 
 
161
static int __init db8500_cpufreq_register(void)
 
162
{
 
163
        if (!cpu_is_u8500v20_or_later())
 
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                return -ENODEV;
 
165
 
 
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        pr_info("cpufreq for DB8500 started\n");
 
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        return cpufreq_register_driver(&db8500_cpufreq_driver);
 
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}
 
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device_initcall(db8500_cpufreq_register);