linux/drivers/cpufreq/tegra-cpufreq.c
Joseph Lo b192b910f3 cpufreq: tegra: fix the wrong clock name
The "cpu" and "pclk_p_cclk" was a virtual clock name that was used in
the legacy Tegra clock framework. It was not used after converting to
CCF. Fix it as the correct clock name that we are using.

Tested-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Joseph Lo <josephl@nvidia.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2013-08-23 21:58:28 +05:30

292 lines
6.6 KiB
C

/*
* Copyright (C) 2010 Google, Inc.
*
* Author:
* Colin Cross <ccross@google.com>
* Based on arch/arm/plat-omap/cpu-omap.c, (C) 2005 Nokia Corporation
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/sched.h>
#include <linux/cpufreq.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/suspend.h>
static struct cpufreq_frequency_table freq_table[] = {
{ .frequency = 216000 },
{ .frequency = 312000 },
{ .frequency = 456000 },
{ .frequency = 608000 },
{ .frequency = 760000 },
{ .frequency = 816000 },
{ .frequency = 912000 },
{ .frequency = 1000000 },
{ .frequency = CPUFREQ_TABLE_END },
};
#define NUM_CPUS 2
static struct clk *cpu_clk;
static struct clk *pll_x_clk;
static struct clk *pll_p_clk;
static struct clk *emc_clk;
static unsigned long target_cpu_speed[NUM_CPUS];
static DEFINE_MUTEX(tegra_cpu_lock);
static bool is_suspended;
static int tegra_verify_speed(struct cpufreq_policy *policy)
{
return cpufreq_frequency_table_verify(policy, freq_table);
}
static unsigned int tegra_getspeed(unsigned int cpu)
{
unsigned long rate;
if (cpu >= NUM_CPUS)
return 0;
rate = clk_get_rate(cpu_clk) / 1000;
return rate;
}
static int tegra_cpu_clk_set_rate(unsigned long rate)
{
int ret;
/*
* Take an extra reference to the main pll so it doesn't turn
* off when we move the cpu off of it
*/
clk_prepare_enable(pll_x_clk);
ret = clk_set_parent(cpu_clk, pll_p_clk);
if (ret) {
pr_err("Failed to switch cpu to clock pll_p\n");
goto out;
}
if (rate == clk_get_rate(pll_p_clk))
goto out;
ret = clk_set_rate(pll_x_clk, rate);
if (ret) {
pr_err("Failed to change pll_x to %lu\n", rate);
goto out;
}
ret = clk_set_parent(cpu_clk, pll_x_clk);
if (ret) {
pr_err("Failed to switch cpu to clock pll_x\n");
goto out;
}
out:
clk_disable_unprepare(pll_x_clk);
return ret;
}
static int tegra_update_cpu_speed(struct cpufreq_policy *policy,
unsigned long rate)
{
int ret = 0;
struct cpufreq_freqs freqs;
freqs.old = tegra_getspeed(0);
freqs.new = rate;
if (freqs.old == freqs.new)
return ret;
/*
* Vote on memory bus frequency based on cpu frequency
* This sets the minimum frequency, display or avp may request higher
*/
if (rate >= 816000)
clk_set_rate(emc_clk, 600000000); /* cpu 816 MHz, emc max */
else if (rate >= 456000)
clk_set_rate(emc_clk, 300000000); /* cpu 456 MHz, emc 150Mhz */
else
clk_set_rate(emc_clk, 100000000); /* emc 50Mhz */
cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
#ifdef CONFIG_CPU_FREQ_DEBUG
printk(KERN_DEBUG "cpufreq-tegra: transition: %u --> %u\n",
freqs.old, freqs.new);
#endif
ret = tegra_cpu_clk_set_rate(freqs.new * 1000);
if (ret) {
pr_err("cpu-tegra: Failed to set cpu frequency to %d kHz\n",
freqs.new);
freqs.new = freqs.old;
}
cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
return ret;
}
static unsigned long tegra_cpu_highest_speed(void)
{
unsigned long rate = 0;
int i;
for_each_online_cpu(i)
rate = max(rate, target_cpu_speed[i]);
return rate;
}
static int tegra_target(struct cpufreq_policy *policy,
unsigned int target_freq,
unsigned int relation)
{
unsigned int idx;
unsigned int freq;
int ret = 0;
mutex_lock(&tegra_cpu_lock);
if (is_suspended) {
ret = -EBUSY;
goto out;
}
cpufreq_frequency_table_target(policy, freq_table, target_freq,
relation, &idx);
freq = freq_table[idx].frequency;
target_cpu_speed[policy->cpu] = freq;
ret = tegra_update_cpu_speed(policy, tegra_cpu_highest_speed());
out:
mutex_unlock(&tegra_cpu_lock);
return ret;
}
static int tegra_pm_notify(struct notifier_block *nb, unsigned long event,
void *dummy)
{
mutex_lock(&tegra_cpu_lock);
if (event == PM_SUSPEND_PREPARE) {
struct cpufreq_policy *policy = cpufreq_cpu_get(0);
is_suspended = true;
pr_info("Tegra cpufreq suspend: setting frequency to %d kHz\n",
freq_table[0].frequency);
tegra_update_cpu_speed(policy, freq_table[0].frequency);
cpufreq_cpu_put(policy);
} else if (event == PM_POST_SUSPEND) {
is_suspended = false;
}
mutex_unlock(&tegra_cpu_lock);
return NOTIFY_OK;
}
static struct notifier_block tegra_cpu_pm_notifier = {
.notifier_call = tegra_pm_notify,
};
static int tegra_cpu_init(struct cpufreq_policy *policy)
{
if (policy->cpu >= NUM_CPUS)
return -EINVAL;
clk_prepare_enable(emc_clk);
clk_prepare_enable(cpu_clk);
cpufreq_frequency_table_cpuinfo(policy, freq_table);
cpufreq_frequency_table_get_attr(freq_table, policy->cpu);
policy->cur = tegra_getspeed(policy->cpu);
target_cpu_speed[policy->cpu] = policy->cur;
/* FIXME: what's the actual transition time? */
policy->cpuinfo.transition_latency = 300 * 1000;
cpumask_copy(policy->cpus, cpu_possible_mask);
if (policy->cpu == 0)
register_pm_notifier(&tegra_cpu_pm_notifier);
return 0;
}
static int tegra_cpu_exit(struct cpufreq_policy *policy)
{
cpufreq_frequency_table_cpuinfo(policy, freq_table);
clk_disable_unprepare(emc_clk);
return 0;
}
static struct freq_attr *tegra_cpufreq_attr[] = {
&cpufreq_freq_attr_scaling_available_freqs,
NULL,
};
static struct cpufreq_driver tegra_cpufreq_driver = {
.verify = tegra_verify_speed,
.target = tegra_target,
.get = tegra_getspeed,
.init = tegra_cpu_init,
.exit = tegra_cpu_exit,
.name = "tegra",
.attr = tegra_cpufreq_attr,
};
static int __init tegra_cpufreq_init(void)
{
cpu_clk = clk_get_sys(NULL, "cclk");
if (IS_ERR(cpu_clk))
return PTR_ERR(cpu_clk);
pll_x_clk = clk_get_sys(NULL, "pll_x");
if (IS_ERR(pll_x_clk))
return PTR_ERR(pll_x_clk);
pll_p_clk = clk_get_sys(NULL, "pll_p");
if (IS_ERR(pll_p_clk))
return PTR_ERR(pll_p_clk);
emc_clk = clk_get_sys("cpu", "emc");
if (IS_ERR(emc_clk)) {
clk_put(cpu_clk);
return PTR_ERR(emc_clk);
}
return cpufreq_register_driver(&tegra_cpufreq_driver);
}
static void __exit tegra_cpufreq_exit(void)
{
cpufreq_unregister_driver(&tegra_cpufreq_driver);
clk_put(emc_clk);
clk_put(cpu_clk);
}
MODULE_AUTHOR("Colin Cross <ccross@android.com>");
MODULE_DESCRIPTION("cpufreq driver for Nvidia Tegra2");
MODULE_LICENSE("GPL");
module_init(tegra_cpufreq_init);
module_exit(tegra_cpufreq_exit);