2005-07-10 12:58:20 -06:00
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/*
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2011-05-26 20:39:18 -06:00
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* CPU frequency scaling for OMAP using OPP information
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2005-07-10 12:58:20 -06:00
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*
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* Copyright (C) 2005 Nokia Corporation
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* Written by Tony Lindgren <tony@atomide.com>
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*
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* Based on cpu-sa1110.c, Copyright (C) 2001 Russell King
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*
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2010-08-11 18:02:43 -06:00
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* Copyright (C) 2007-2011 Texas Instruments, Inc.
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* - OMAP3/4 support by Rajendra Nayak, Santosh Shilimkar
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*
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2005-07-10 12:58:20 -06:00
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/sched.h>
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#include <linux/cpufreq.h>
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#include <linux/delay.h>
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#include <linux/init.h>
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#include <linux/err.h>
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2006-01-07 09:15:52 -07:00
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#include <linux/clk.h>
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2008-09-06 05:10:45 -06:00
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#include <linux/io.h>
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2013-09-19 15:03:52 -06:00
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#include <linux/pm_opp.h>
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2011-09-21 17:53:00 -06:00
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#include <linux/cpu.h>
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2011-09-30 11:41:26 -06:00
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#include <linux/module.h>
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cpufreq: OMAP: instantiate omap-cpufreq as a platform_driver
As multi-platform build is being adopted by more and more ARM platforms,
initcall function should be used very carefully. For example, when
CONFIG_ARM_OMAP2PLUS_CPUFREQ is built in the kernel, omap_cpufreq_init()
will be called on all the platforms to initialize omap-cpufreq driver.
Further, on OMAP, we now use Soc generic cpufreq-cpu0 driver using device
tree entries. To allow cpufreq-cpu0 and omap-cpufreq drivers to co-exist
for OMAP in a single image, we need to ensure the following:
1. With device tree boot, we use cpufreq-cpu0
2. With non device tree boot, we use omap-cpufreq
In the case of (1), we will have cpu OPPs and regulator registered
as part of the device tree nodes, to ensure that omap-cpufreq
and cpufreq-cpu0 don't conflict in managing the frequency of the
same CPU, we should not permit omap-cpufreq to be probed.
In the case of (2), we will not have the cpufreq-cpu0 device, hence
only omap-cpufreq will be active.
To eliminate this undesired these effects, we change omap-cpufreq
driver to have it instantiated as a platform_driver and register
"omap-cpufreq" device only when booted without device tree nodes on
OMAP platforms.
This allows the following:
a) Will only run on platforms that create the platform_device
"omap-cpufreq".
b) Since the platform_device is registered only when device tree nodes
are *not* populated, omap-cpufreq driver does not conflict with
the usage of cpufreq-cpu0 driver which is used on OMAP platforms when
device tree nodes are present.
Inspired by commit 5553f9e26f6f49a93ba732fd222eac6973a4cf35
(cpufreq: instantiate cpufreq-cpu0 as a platform_driver)
[robherring2@gmail.com: reported conflict of omap-cpufreq vs other
driver in an non-device tree supported boot]
Reported-by: Rob Herring <robherring2@gmail.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-04-09 17:22:01 -06:00
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#include <linux/platform_device.h>
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2011-07-15 16:05:04 -06:00
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#include <linux/regulator/consumer.h>
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2005-07-10 12:58:20 -06:00
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2010-08-11 18:02:43 -06:00
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#include <asm/smp_plat.h>
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2011-09-21 17:53:00 -06:00
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#include <asm/cpu.h>
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2005-07-10 12:58:20 -06:00
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2012-02-23 06:49:24 -07:00
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/* OPP tolerance in percentage */
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#define OPP_TOLERANCE 4
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2010-08-11 18:02:43 -06:00
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static struct cpufreq_frequency_table *freq_table;
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2011-05-26 20:39:20 -06:00
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static atomic_t freq_table_users = ATOMIC_INIT(0);
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2007-08-30 03:46:39 -06:00
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static struct clk *mpu_clk;
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2011-05-25 17:38:47 -06:00
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static struct device *mpu_dev;
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2011-07-15 16:05:04 -06:00
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static struct regulator *mpu_reg;
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2007-08-30 03:46:39 -06:00
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2010-10-08 11:00:19 -06:00
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static unsigned int omap_getspeed(unsigned int cpu)
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2005-07-10 12:58:20 -06:00
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{
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unsigned long rate;
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2011-09-21 17:53:00 -06:00
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if (cpu >= NR_CPUS)
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2005-07-10 12:58:20 -06:00
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return 0;
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rate = clk_get_rate(mpu_clk) / 1000;
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return rate;
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}
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2013-10-25 08:15:48 -06:00
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static int omap_target(struct cpufreq_policy *policy, unsigned int index)
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2005-07-10 12:58:20 -06:00
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{
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2013-11-13 03:09:23 -07:00
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int r, ret;
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2013-09-19 15:03:51 -06:00
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struct dev_pm_opp *opp;
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2012-02-23 06:49:24 -07:00
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unsigned long freq, volt = 0, volt_old = 0, tol = 0;
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2013-08-14 08:08:24 -06:00
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unsigned int old_freq, new_freq;
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2005-07-10 12:58:20 -06:00
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2013-08-14 08:08:24 -06:00
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old_freq = omap_getspeed(policy->cpu);
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new_freq = freq_table[index].frequency;
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2009-01-27 19:13:38 -07:00
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2013-08-14 08:08:24 -06:00
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freq = new_freq * 1000;
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2012-10-02 16:39:03 -06:00
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ret = clk_round_rate(mpu_clk, freq);
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if (IS_ERR_VALUE(ret)) {
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dev_warn(mpu_dev,
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"CPUfreq: Cannot find matching frequency for %lu\n",
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freq);
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return ret;
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}
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freq = ret;
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2011-07-15 16:05:04 -06:00
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if (mpu_reg) {
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2013-01-18 12:52:32 -07:00
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rcu_read_lock();
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2013-09-19 15:03:50 -06:00
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opp = dev_pm_opp_find_freq_ceil(mpu_dev, &freq);
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2011-07-15 16:05:04 -06:00
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if (IS_ERR(opp)) {
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2013-01-18 12:52:32 -07:00
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rcu_read_unlock();
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2011-07-15 16:05:04 -06:00
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dev_err(mpu_dev, "%s: unable to find MPU OPP for %d\n",
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2013-08-14 08:08:24 -06:00
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__func__, new_freq);
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2011-07-15 16:05:04 -06:00
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return -EINVAL;
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}
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2013-09-19 15:03:50 -06:00
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volt = dev_pm_opp_get_voltage(opp);
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2013-01-18 12:52:32 -07:00
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rcu_read_unlock();
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2012-02-23 06:49:24 -07:00
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tol = volt * OPP_TOLERANCE / 100;
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2011-07-15 16:05:04 -06:00
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volt_old = regulator_get_voltage(mpu_reg);
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}
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dev_dbg(mpu_dev, "cpufreq-omap: %u MHz, %ld mV --> %u MHz, %ld mV\n",
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2013-08-14 08:08:24 -06:00
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old_freq / 1000, volt_old ? volt_old / 1000 : -1,
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new_freq / 1000, volt ? volt / 1000 : -1);
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2013-06-18 23:48:20 -06:00
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2011-07-15 16:05:04 -06:00
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/* scaling up? scale voltage before frequency */
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2013-08-14 08:08:24 -06:00
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if (mpu_reg && (new_freq > old_freq)) {
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2012-02-23 06:49:24 -07:00
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r = regulator_set_voltage(mpu_reg, volt - tol, volt + tol);
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2011-07-15 16:05:04 -06:00
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if (r < 0) {
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dev_warn(mpu_dev, "%s: unable to scale voltage up.\n",
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__func__);
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2013-08-14 08:08:24 -06:00
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return r;
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2011-07-15 16:05:04 -06:00
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}
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}
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2010-08-11 18:02:43 -06:00
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2013-08-14 08:08:24 -06:00
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ret = clk_set_rate(mpu_clk, new_freq * 1000);
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2011-09-21 17:53:00 -06:00
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2011-07-15 16:05:04 -06:00
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/* scaling down? scale voltage after frequency */
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2013-08-14 08:08:24 -06:00
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if (mpu_reg && (new_freq < old_freq)) {
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2012-02-23 06:49:24 -07:00
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r = regulator_set_voltage(mpu_reg, volt - tol, volt + tol);
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2011-07-15 16:05:04 -06:00
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if (r < 0) {
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dev_warn(mpu_dev, "%s: unable to scale voltage down.\n",
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__func__);
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2013-08-14 08:08:24 -06:00
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clk_set_rate(mpu_clk, old_freq * 1000);
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return r;
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2011-07-15 16:05:04 -06:00
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}
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}
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2005-07-10 12:58:20 -06:00
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return ret;
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}
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2011-05-26 20:39:20 -06:00
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static inline void freq_table_free(void)
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{
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if (atomic_dec_and_test(&freq_table_users))
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2013-09-19 15:03:50 -06:00
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dev_pm_opp_free_cpufreq_table(mpu_dev, &freq_table);
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2011-05-26 20:39:20 -06:00
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}
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2013-06-19 11:54:04 -06:00
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static int omap_cpu_init(struct cpufreq_policy *policy)
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2005-07-10 12:58:20 -06:00
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{
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2013-10-03 08:59:18 -06:00
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int result;
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2010-08-11 18:02:43 -06:00
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2012-09-07 12:16:35 -06:00
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mpu_clk = clk_get(NULL, "cpufreq_ck");
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2005-07-10 12:58:20 -06:00
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if (IS_ERR(mpu_clk))
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return PTR_ERR(mpu_clk);
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2013-10-03 08:59:18 -06:00
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if (!freq_table) {
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2013-09-19 15:03:50 -06:00
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result = dev_pm_opp_init_cpufreq_table(mpu_dev, &freq_table);
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2013-10-03 08:59:18 -06:00
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if (result) {
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dev_err(mpu_dev,
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"%s: cpu%d: failed creating freq table[%d]\n",
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2011-05-26 20:39:17 -06:00
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__func__, policy->cpu, result);
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2013-10-03 08:59:18 -06:00
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goto fail;
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}
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2009-01-27 19:13:38 -07:00
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}
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2012-08-09 01:08:21 -06:00
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atomic_inc_return(&freq_table_users);
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2009-01-27 19:13:38 -07:00
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/* FIXME: what's the actual transition time? */
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2013-10-03 08:59:18 -06:00
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result = cpufreq_generic_init(policy, freq_table, 300 * 1000);
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if (!result)
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return 0;
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2011-05-26 20:39:19 -06:00
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2011-05-26 20:39:20 -06:00
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freq_table_free();
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2013-10-03 08:59:18 -06:00
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fail:
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2011-05-26 20:39:19 -06:00
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clk_put(mpu_clk);
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return result;
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2005-07-10 12:58:20 -06:00
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}
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2007-08-30 03:46:39 -06:00
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static int omap_cpu_exit(struct cpufreq_policy *policy)
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{
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2013-09-16 07:26:46 -06:00
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cpufreq_frequency_table_put_attr(policy->cpu);
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2011-05-26 20:39:20 -06:00
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freq_table_free();
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2007-08-30 03:46:39 -06:00
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clk_put(mpu_clk);
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return 0;
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}
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2005-07-10 12:58:20 -06:00
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static struct cpufreq_driver omap_driver = {
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.flags = CPUFREQ_STICKY,
|
2013-10-03 08:58:13 -06:00
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.verify = cpufreq_generic_frequency_table_verify,
|
2013-10-25 08:15:48 -06:00
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.target_index = omap_target,
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2005-07-10 12:58:20 -06:00
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.get = omap_getspeed,
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.init = omap_cpu_init,
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2007-08-30 03:46:39 -06:00
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.exit = omap_cpu_exit,
|
2005-07-10 12:58:20 -06:00
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.name = "omap",
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2013-10-03 08:58:13 -06:00
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.attr = cpufreq_generic_attr,
|
2005-07-10 12:58:20 -06:00
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};
|
|
|
|
|
cpufreq: OMAP: instantiate omap-cpufreq as a platform_driver
As multi-platform build is being adopted by more and more ARM platforms,
initcall function should be used very carefully. For example, when
CONFIG_ARM_OMAP2PLUS_CPUFREQ is built in the kernel, omap_cpufreq_init()
will be called on all the platforms to initialize omap-cpufreq driver.
Further, on OMAP, we now use Soc generic cpufreq-cpu0 driver using device
tree entries. To allow cpufreq-cpu0 and omap-cpufreq drivers to co-exist
for OMAP in a single image, we need to ensure the following:
1. With device tree boot, we use cpufreq-cpu0
2. With non device tree boot, we use omap-cpufreq
In the case of (1), we will have cpu OPPs and regulator registered
as part of the device tree nodes, to ensure that omap-cpufreq
and cpufreq-cpu0 don't conflict in managing the frequency of the
same CPU, we should not permit omap-cpufreq to be probed.
In the case of (2), we will not have the cpufreq-cpu0 device, hence
only omap-cpufreq will be active.
To eliminate this undesired these effects, we change omap-cpufreq
driver to have it instantiated as a platform_driver and register
"omap-cpufreq" device only when booted without device tree nodes on
OMAP platforms.
This allows the following:
a) Will only run on platforms that create the platform_device
"omap-cpufreq".
b) Since the platform_device is registered only when device tree nodes
are *not* populated, omap-cpufreq driver does not conflict with
the usage of cpufreq-cpu0 driver which is used on OMAP platforms when
device tree nodes are present.
Inspired by commit 5553f9e26f6f49a93ba732fd222eac6973a4cf35
(cpufreq: instantiate cpufreq-cpu0 as a platform_driver)
[robherring2@gmail.com: reported conflict of omap-cpufreq vs other
driver in an non-device tree supported boot]
Reported-by: Rob Herring <robherring2@gmail.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-04-09 17:22:01 -06:00
|
|
|
static int omap_cpufreq_probe(struct platform_device *pdev)
|
2005-07-10 12:58:20 -06:00
|
|
|
{
|
2012-09-06 15:22:44 -06:00
|
|
|
mpu_dev = get_cpu_device(0);
|
|
|
|
if (!mpu_dev) {
|
2011-05-25 17:38:47 -06:00
|
|
|
pr_warning("%s: unable to get the mpu device\n", __func__);
|
2012-09-06 15:22:44 -06:00
|
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|
return -EINVAL;
|
2011-05-25 17:38:47 -06:00
|
|
|
}
|
|
|
|
|
2011-07-15 16:05:04 -06:00
|
|
|
mpu_reg = regulator_get(mpu_dev, "vcc");
|
|
|
|
if (IS_ERR(mpu_reg)) {
|
|
|
|
pr_warning("%s: unable to get MPU regulator\n", __func__);
|
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|
mpu_reg = NULL;
|
|
|
|
} else {
|
|
|
|
/*
|
|
|
|
* Ensure physical regulator is present.
|
|
|
|
* (e.g. could be dummy regulator.)
|
|
|
|
*/
|
|
|
|
if (regulator_get_voltage(mpu_reg) < 0) {
|
|
|
|
pr_warn("%s: physical regulator not present for MPU\n",
|
|
|
|
__func__);
|
|
|
|
regulator_put(mpu_reg);
|
|
|
|
mpu_reg = NULL;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2005-07-10 12:58:20 -06:00
|
|
|
return cpufreq_register_driver(&omap_driver);
|
|
|
|
}
|
|
|
|
|
cpufreq: OMAP: instantiate omap-cpufreq as a platform_driver
As multi-platform build is being adopted by more and more ARM platforms,
initcall function should be used very carefully. For example, when
CONFIG_ARM_OMAP2PLUS_CPUFREQ is built in the kernel, omap_cpufreq_init()
will be called on all the platforms to initialize omap-cpufreq driver.
Further, on OMAP, we now use Soc generic cpufreq-cpu0 driver using device
tree entries. To allow cpufreq-cpu0 and omap-cpufreq drivers to co-exist
for OMAP in a single image, we need to ensure the following:
1. With device tree boot, we use cpufreq-cpu0
2. With non device tree boot, we use omap-cpufreq
In the case of (1), we will have cpu OPPs and regulator registered
as part of the device tree nodes, to ensure that omap-cpufreq
and cpufreq-cpu0 don't conflict in managing the frequency of the
same CPU, we should not permit omap-cpufreq to be probed.
In the case of (2), we will not have the cpufreq-cpu0 device, hence
only omap-cpufreq will be active.
To eliminate this undesired these effects, we change omap-cpufreq
driver to have it instantiated as a platform_driver and register
"omap-cpufreq" device only when booted without device tree nodes on
OMAP platforms.
This allows the following:
a) Will only run on platforms that create the platform_device
"omap-cpufreq".
b) Since the platform_device is registered only when device tree nodes
are *not* populated, omap-cpufreq driver does not conflict with
the usage of cpufreq-cpu0 driver which is used on OMAP platforms when
device tree nodes are present.
Inspired by commit 5553f9e26f6f49a93ba732fd222eac6973a4cf35
(cpufreq: instantiate cpufreq-cpu0 as a platform_driver)
[robherring2@gmail.com: reported conflict of omap-cpufreq vs other
driver in an non-device tree supported boot]
Reported-by: Rob Herring <robherring2@gmail.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-04-09 17:22:01 -06:00
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static int omap_cpufreq_remove(struct platform_device *pdev)
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2010-08-11 18:02:43 -06:00
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{
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cpufreq: OMAP: instantiate omap-cpufreq as a platform_driver
As multi-platform build is being adopted by more and more ARM platforms,
initcall function should be used very carefully. For example, when
CONFIG_ARM_OMAP2PLUS_CPUFREQ is built in the kernel, omap_cpufreq_init()
will be called on all the platforms to initialize omap-cpufreq driver.
Further, on OMAP, we now use Soc generic cpufreq-cpu0 driver using device
tree entries. To allow cpufreq-cpu0 and omap-cpufreq drivers to co-exist
for OMAP in a single image, we need to ensure the following:
1. With device tree boot, we use cpufreq-cpu0
2. With non device tree boot, we use omap-cpufreq
In the case of (1), we will have cpu OPPs and regulator registered
as part of the device tree nodes, to ensure that omap-cpufreq
and cpufreq-cpu0 don't conflict in managing the frequency of the
same CPU, we should not permit omap-cpufreq to be probed.
In the case of (2), we will not have the cpufreq-cpu0 device, hence
only omap-cpufreq will be active.
To eliminate this undesired these effects, we change omap-cpufreq
driver to have it instantiated as a platform_driver and register
"omap-cpufreq" device only when booted without device tree nodes on
OMAP platforms.
This allows the following:
a) Will only run on platforms that create the platform_device
"omap-cpufreq".
b) Since the platform_device is registered only when device tree nodes
are *not* populated, omap-cpufreq driver does not conflict with
the usage of cpufreq-cpu0 driver which is used on OMAP platforms when
device tree nodes are present.
Inspired by commit 5553f9e26f6f49a93ba732fd222eac6973a4cf35
(cpufreq: instantiate cpufreq-cpu0 as a platform_driver)
[robherring2@gmail.com: reported conflict of omap-cpufreq vs other
driver in an non-device tree supported boot]
Reported-by: Rob Herring <robherring2@gmail.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-04-09 17:22:01 -06:00
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return cpufreq_unregister_driver(&omap_driver);
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2010-08-11 18:02:43 -06:00
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}
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2009-01-27 19:13:38 -07:00
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cpufreq: OMAP: instantiate omap-cpufreq as a platform_driver
As multi-platform build is being adopted by more and more ARM platforms,
initcall function should be used very carefully. For example, when
CONFIG_ARM_OMAP2PLUS_CPUFREQ is built in the kernel, omap_cpufreq_init()
will be called on all the platforms to initialize omap-cpufreq driver.
Further, on OMAP, we now use Soc generic cpufreq-cpu0 driver using device
tree entries. To allow cpufreq-cpu0 and omap-cpufreq drivers to co-exist
for OMAP in a single image, we need to ensure the following:
1. With device tree boot, we use cpufreq-cpu0
2. With non device tree boot, we use omap-cpufreq
In the case of (1), we will have cpu OPPs and regulator registered
as part of the device tree nodes, to ensure that omap-cpufreq
and cpufreq-cpu0 don't conflict in managing the frequency of the
same CPU, we should not permit omap-cpufreq to be probed.
In the case of (2), we will not have the cpufreq-cpu0 device, hence
only omap-cpufreq will be active.
To eliminate this undesired these effects, we change omap-cpufreq
driver to have it instantiated as a platform_driver and register
"omap-cpufreq" device only when booted without device tree nodes on
OMAP platforms.
This allows the following:
a) Will only run on platforms that create the platform_device
"omap-cpufreq".
b) Since the platform_device is registered only when device tree nodes
are *not* populated, omap-cpufreq driver does not conflict with
the usage of cpufreq-cpu0 driver which is used on OMAP platforms when
device tree nodes are present.
Inspired by commit 5553f9e26f6f49a93ba732fd222eac6973a4cf35
(cpufreq: instantiate cpufreq-cpu0 as a platform_driver)
[robherring2@gmail.com: reported conflict of omap-cpufreq vs other
driver in an non-device tree supported boot]
Reported-by: Rob Herring <robherring2@gmail.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-04-09 17:22:01 -06:00
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static struct platform_driver omap_cpufreq_platdrv = {
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.driver = {
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.name = "omap-cpufreq",
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.owner = THIS_MODULE,
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},
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.probe = omap_cpufreq_probe,
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.remove = omap_cpufreq_remove,
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};
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module_platform_driver(omap_cpufreq_platdrv);
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2010-08-11 18:02:43 -06:00
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MODULE_DESCRIPTION("cpufreq driver for OMAP SoCs");
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MODULE_LICENSE("GPL");
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