2005-07-10 20:58:20 +02:00
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/*
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2011-05-27 04:39:18 +02:00
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* CPU frequency scaling for OMAP using OPP information
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2005-07-10 20:58:20 +02:00
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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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2010-08-12 02:02:43 +02:00
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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 20:58:20 +02:00
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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 17:15:52 +01:00
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#include <linux/clk.h>
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2008-09-06 13:10:45 +02:00
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#include <linux/io.h>
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2010-08-12 02:02:43 +02:00
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#include <linux/opp.h>
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2011-09-22 01:53:00 +02:00
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#include <linux/cpu.h>
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2011-09-30 19:41:26 +02:00
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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>
2013-04-10 01:22:01 +02:00
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#include <linux/platform_device.h>
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2011-07-16 00:05:04 +02:00
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#include <linux/regulator/consumer.h>
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2005-07-10 20:58:20 +02:00
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2010-08-12 02:02:43 +02:00
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#include <asm/smp_plat.h>
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2011-09-22 01:53:00 +02:00
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#include <asm/cpu.h>
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2005-07-10 20:58:20 +02:00
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2012-02-23 14:49:24 +01:00
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/* OPP tolerance in percentage */
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#define OPP_TOLERANCE 4
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2010-08-12 02:02:43 +02:00
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static struct cpufreq_frequency_table *freq_table;
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2011-05-27 04:39:20 +02:00
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static atomic_t freq_table_users = ATOMIC_INIT(0);
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2007-08-30 11:46:39 +02:00
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static struct clk *mpu_clk;
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2011-05-26 01:38:47 +02:00
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static struct device *mpu_dev;
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2011-07-16 00:05:04 +02:00
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static struct regulator *mpu_reg;
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2007-08-30 11:46:39 +02:00
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2010-10-08 19:00:19 +02:00
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static int omap_verify_speed(struct cpufreq_policy *policy)
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2005-07-10 20:58:20 +02:00
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{
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2011-05-27 04:39:17 +02:00
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if (!freq_table)
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2005-07-10 20:58:20 +02:00
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return -EINVAL;
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2011-05-27 04:39:17 +02:00
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return cpufreq_frequency_table_verify(policy, freq_table);
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2005-07-10 20:58:20 +02:00
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}
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2010-10-08 19:00:19 +02:00
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static unsigned int omap_getspeed(unsigned int cpu)
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2005-07-10 20:58:20 +02:00
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{
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unsigned long rate;
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2011-09-22 01:53:00 +02:00
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if (cpu >= NR_CPUS)
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2005-07-10 20:58:20 +02:00
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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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static int omap_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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2011-05-27 04:39:17 +02:00
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unsigned int i;
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2011-07-16 00:05:04 +02:00
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int r, ret = 0;
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2010-08-12 02:02:43 +02:00
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struct cpufreq_freqs freqs;
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2013-09-19 23:03:51 +02:00
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struct dev_pm_opp *opp;
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2012-02-23 14:49:24 +01:00
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unsigned long freq, volt = 0, volt_old = 0, tol = 0;
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2005-07-10 20:58:20 +02:00
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2011-05-27 04:39:17 +02:00
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if (!freq_table) {
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dev_err(mpu_dev, "%s: cpu%d: no freq table!\n", __func__,
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policy->cpu);
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return -EINVAL;
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}
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ret = cpufreq_frequency_table_target(policy, freq_table, target_freq,
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relation, &i);
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if (ret) {
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dev_dbg(mpu_dev, "%s: cpu%d: no freq match for %d(ret=%d)\n",
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__func__, policy->cpu, target_freq, ret);
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return ret;
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}
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freqs.new = freq_table[i].frequency;
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if (!freqs.new) {
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dev_err(mpu_dev, "%s: cpu%d: no match for freq %d\n", __func__,
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policy->cpu, target_freq);
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return -EINVAL;
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}
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2009-01-28 03:13:38 +01:00
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2011-09-22 01:53:00 +02:00
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freqs.old = omap_getspeed(policy->cpu);
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2005-07-10 20:58:20 +02:00
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2011-06-07 04:05:29 +02:00
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if (freqs.old == freqs.new && policy->cur == freqs.new)
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2009-01-28 03:13:38 +01:00
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return ret;
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2011-07-16 00:05:04 +02:00
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freq = freqs.new * 1000;
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2012-10-03 00:39:03 +02:00
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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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2011-07-16 00:05:04 +02:00
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if (mpu_reg) {
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2013-01-18 20:52:32 +01:00
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rcu_read_lock();
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2013-09-19 23:03:50 +02:00
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opp = dev_pm_opp_find_freq_ceil(mpu_dev, &freq);
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2011-07-16 00:05:04 +02:00
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if (IS_ERR(opp)) {
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2013-01-18 20:52:32 +01:00
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rcu_read_unlock();
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2011-07-16 00:05:04 +02:00
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dev_err(mpu_dev, "%s: unable to find MPU OPP for %d\n",
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__func__, freqs.new);
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return -EINVAL;
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}
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2013-09-19 23:03:50 +02:00
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volt = dev_pm_opp_get_voltage(opp);
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2013-01-18 20:52:32 +01:00
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rcu_read_unlock();
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2012-02-23 14:49:24 +01:00
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tol = volt * OPP_TOLERANCE / 100;
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2011-07-16 00:05:04 +02:00
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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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freqs.old / 1000, volt_old ? volt_old / 1000 : -1,
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freqs.new / 1000, volt ? volt / 1000 : -1);
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2013-06-19 07:48:20 +02:00
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/* notifiers */
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cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
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2011-07-16 00:05:04 +02:00
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/* scaling up? scale voltage before frequency */
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if (mpu_reg && (freqs.new > freqs.old)) {
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2012-02-23 14:49:24 +01:00
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r = regulator_set_voltage(mpu_reg, volt - tol, volt + tol);
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2011-07-16 00:05:04 +02:00
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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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freqs.new = freqs.old;
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goto done;
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}
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}
|
2010-08-12 02:02:43 +02:00
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2009-01-28 03:13:38 +01:00
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ret = clk_set_rate(mpu_clk, freqs.new * 1000);
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2011-09-22 01:53:00 +02:00
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2011-07-16 00:05:04 +02:00
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/* scaling down? scale voltage after frequency */
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if (mpu_reg && (freqs.new < freqs.old)) {
|
2012-02-23 14:49:24 +01:00
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r = regulator_set_voltage(mpu_reg, volt - tol, volt + tol);
|
2011-07-16 00:05:04 +02:00
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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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ret = clk_set_rate(mpu_clk, freqs.old * 1000);
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freqs.new = freqs.old;
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goto done;
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}
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}
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freqs.new = omap_getspeed(policy->cpu);
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2011-09-22 01:53:00 +02:00
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2011-07-16 00:05:04 +02:00
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done:
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2011-09-22 01:53:00 +02:00
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/* notifiers */
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2013-03-24 07:26:43 +01:00
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cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
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2005-07-10 20:58:20 +02:00
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return ret;
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}
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|
2011-05-27 04:39:20 +02:00
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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 23:03:50 +02:00
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dev_pm_opp_free_cpufreq_table(mpu_dev, &freq_table);
|
2011-05-27 04:39:20 +02:00
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}
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|
2013-06-19 19:54:04 +02:00
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static int omap_cpu_init(struct cpufreq_policy *policy)
|
2005-07-10 20:58:20 +02:00
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{
|
2009-01-28 03:13:38 +01:00
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int result = 0;
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2010-08-12 02:02:43 +02:00
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2012-09-07 20:16:35 +02:00
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mpu_clk = clk_get(NULL, "cpufreq_ck");
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2005-07-10 20:58:20 +02:00
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if (IS_ERR(mpu_clk))
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return PTR_ERR(mpu_clk);
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2011-05-27 04:39:19 +02:00
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if (policy->cpu >= NR_CPUS) {
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result = -EINVAL;
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goto fail_ck;
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}
|
2009-01-28 03:13:38 +01:00
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|
2013-04-01 14:57:48 +02:00
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policy->cur = omap_getspeed(policy->cpu);
|
2011-05-27 04:39:20 +02:00
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2012-08-09 09:08:21 +02:00
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if (!freq_table)
|
2013-09-19 23:03:50 +02:00
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result = dev_pm_opp_init_cpufreq_table(mpu_dev, &freq_table);
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2011-05-27 04:39:17 +02:00
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if (result) {
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dev_err(mpu_dev, "%s: cpu%d: failed creating freq table[%d]\n",
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__func__, policy->cpu, result);
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2011-05-27 04:39:19 +02:00
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goto fail_ck;
|
2009-01-28 03:13:38 +01:00
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}
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2012-08-09 09:08:21 +02:00
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atomic_inc_return(&freq_table_users);
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2011-05-27 04:39:17 +02:00
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result = cpufreq_frequency_table_cpuinfo(policy, freq_table);
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2011-05-27 04:39:20 +02:00
|
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if (result)
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goto fail_table;
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cpufreq_frequency_table_get_attr(freq_table, policy->cpu);
|
2011-05-27 04:39:17 +02:00
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2011-09-22 01:53:00 +02:00
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policy->cur = omap_getspeed(policy->cpu);
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|
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/*
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* On OMAP SMP configuartion, both processors share the voltage
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* and clock. So both CPUs needs to be scaled together and hence
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* needs software co-ordination. Use cpufreq affected_cpus
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* interface to handle this scenario. Additional is_smp() check
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* is to keep SMP_ON_UP build working.
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|
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|
*/
|
2013-02-01 07:40:02 +01:00
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|
if (is_smp())
|
2011-06-07 22:57:52 +02:00
|
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cpumask_setall(policy->cpus);
|
2010-08-12 02:02:43 +02:00
|
|
|
|
2009-01-28 03:13:38 +01:00
|
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/* FIXME: what's the actual transition time? */
|
2009-11-11 20:00:38 +01:00
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|
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policy->cpuinfo.transition_latency = 300 * 1000;
|
2005-07-10 20:58:20 +02:00
|
|
|
|
|
|
|
return 0;
|
2011-05-27 04:39:19 +02:00
|
|
|
|
2011-05-27 04:39:20 +02:00
|
|
|
fail_table:
|
|
|
|
freq_table_free();
|
2011-05-27 04:39:19 +02:00
|
|
|
fail_ck:
|
|
|
|
clk_put(mpu_clk);
|
|
|
|
return result;
|
2005-07-10 20:58:20 +02:00
|
|
|
}
|
|
|
|
|
2007-08-30 11:46:39 +02:00
|
|
|
static int omap_cpu_exit(struct cpufreq_policy *policy)
|
|
|
|
{
|
2011-05-27 04:39:20 +02:00
|
|
|
freq_table_free();
|
2007-08-30 11:46:39 +02:00
|
|
|
clk_put(mpu_clk);
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2009-01-28 03:13:38 +01:00
|
|
|
static struct freq_attr *omap_cpufreq_attr[] = {
|
|
|
|
&cpufreq_freq_attr_scaling_available_freqs,
|
|
|
|
NULL,
|
|
|
|
};
|
|
|
|
|
2005-07-10 20:58:20 +02:00
|
|
|
static struct cpufreq_driver omap_driver = {
|
|
|
|
.flags = CPUFREQ_STICKY,
|
|
|
|
.verify = omap_verify_speed,
|
|
|
|
.target = omap_target,
|
|
|
|
.get = omap_getspeed,
|
|
|
|
.init = omap_cpu_init,
|
2007-08-30 11:46:39 +02:00
|
|
|
.exit = omap_cpu_exit,
|
2005-07-10 20:58:20 +02:00
|
|
|
.name = "omap",
|
2009-01-28 03:13:38 +01:00
|
|
|
.attr = omap_cpufreq_attr,
|
2005-07-10 20:58:20 +02:00
|
|
|
};
|
|
|
|
|
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>
2013-04-10 01:22:01 +02:00
|
|
|
static int omap_cpufreq_probe(struct platform_device *pdev)
|
2005-07-10 20:58:20 +02:00
|
|
|
{
|
2012-09-06 23:22:44 +02:00
|
|
|
mpu_dev = get_cpu_device(0);
|
|
|
|
if (!mpu_dev) {
|
2011-05-26 01:38:47 +02:00
|
|
|
pr_warning("%s: unable to get the mpu device\n", __func__);
|
2012-09-06 23:22:44 +02:00
|
|
|
return -EINVAL;
|
2011-05-26 01:38:47 +02:00
|
|
|
}
|
|
|
|
|
2011-07-16 00:05:04 +02:00
|
|
|
mpu_reg = regulator_get(mpu_dev, "vcc");
|
|
|
|
if (IS_ERR(mpu_reg)) {
|
|
|
|
pr_warning("%s: unable to get MPU regulator\n", __func__);
|
|
|
|
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 20:58:20 +02:00
|
|
|
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>
2013-04-10 01:22:01 +02:00
|
|
|
static int omap_cpufreq_remove(struct platform_device *pdev)
|
2010-08-12 02:02:43 +02:00
|
|
|
{
|
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>
2013-04-10 01:22:01 +02:00
|
|
|
return cpufreq_unregister_driver(&omap_driver);
|
2010-08-12 02:02:43 +02:00
|
|
|
}
|
2009-01-28 03:13:38 +01:00
|
|
|
|
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>
2013-04-10 01:22:01 +02:00
|
|
|
static struct platform_driver omap_cpufreq_platdrv = {
|
|
|
|
.driver = {
|
|
|
|
.name = "omap-cpufreq",
|
|
|
|
.owner = THIS_MODULE,
|
|
|
|
},
|
|
|
|
.probe = omap_cpufreq_probe,
|
|
|
|
.remove = omap_cpufreq_remove,
|
|
|
|
};
|
|
|
|
module_platform_driver(omap_cpufreq_platdrv);
|
|
|
|
|
2010-08-12 02:02:43 +02:00
|
|
|
MODULE_DESCRIPTION("cpufreq driver for OMAP SoCs");
|
|
|
|
MODULE_LICENSE("GPL");
|