linux/drivers/cpufreq/omap-cpufreq.c
Linus Torvalds 0195c00244 Disintegrate and delete asm/system.h
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Merge tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system

Pull "Disintegrate and delete asm/system.h" from David Howells:
 "Here are a bunch of patches to disintegrate asm/system.h into a set of
  separate bits to relieve the problem of circular inclusion
  dependencies.

  I've built all the working defconfigs from all the arches that I can
  and made sure that they don't break.

  The reason for these patches is that I recently encountered a circular
  dependency problem that came about when I produced some patches to
  optimise get_order() by rewriting it to use ilog2().

  This uses bitops - and on the SH arch asm/bitops.h drags in
  asm-generic/get_order.h by a circuituous route involving asm/system.h.

  The main difficulty seems to be asm/system.h.  It holds a number of
  low level bits with no/few dependencies that are commonly used (eg.
  memory barriers) and a number of bits with more dependencies that
  aren't used in many places (eg.  switch_to()).

  These patches break asm/system.h up into the following core pieces:

    (1) asm/barrier.h

        Move memory barriers here.  This already done for MIPS and Alpha.

    (2) asm/switch_to.h

        Move switch_to() and related stuff here.

    (3) asm/exec.h

        Move arch_align_stack() here.  Other process execution related bits
        could perhaps go here from asm/processor.h.

    (4) asm/cmpxchg.h

        Move xchg() and cmpxchg() here as they're full word atomic ops and
        frequently used by atomic_xchg() and atomic_cmpxchg().

    (5) asm/bug.h

        Move die() and related bits.

    (6) asm/auxvec.h

        Move AT_VECTOR_SIZE_ARCH here.

  Other arch headers are created as needed on a per-arch basis."

Fixed up some conflicts from other header file cleanups and moving code
around that has happened in the meantime, so David's testing is somewhat
weakened by that.  We'll find out anything that got broken and fix it..

* tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system: (38 commits)
  Delete all instances of asm/system.h
  Remove all #inclusions of asm/system.h
  Add #includes needed to permit the removal of asm/system.h
  Move all declarations of free_initmem() to linux/mm.h
  Disintegrate asm/system.h for OpenRISC
  Split arch_align_stack() out from asm-generic/system.h
  Split the switch_to() wrapper out of asm-generic/system.h
  Move the asm-generic/system.h xchg() implementation to asm-generic/cmpxchg.h
  Create asm-generic/barrier.h
  Make asm-generic/cmpxchg.h #include asm-generic/cmpxchg-local.h
  Disintegrate asm/system.h for Xtensa
  Disintegrate asm/system.h for Unicore32 [based on ver #3, changed by gxt]
  Disintegrate asm/system.h for Tile
  Disintegrate asm/system.h for Sparc
  Disintegrate asm/system.h for SH
  Disintegrate asm/system.h for Score
  Disintegrate asm/system.h for S390
  Disintegrate asm/system.h for PowerPC
  Disintegrate asm/system.h for PA-RISC
  Disintegrate asm/system.h for MN10300
  ...
2012-03-28 15:58:21 -07:00

335 lines
8 KiB
C

/*
* CPU frequency scaling for OMAP using OPP information
*
* Copyright (C) 2005 Nokia Corporation
* Written by Tony Lindgren <tony@atomide.com>
*
* Based on cpu-sa1110.c, Copyright (C) 2001 Russell King
*
* Copyright (C) 2007-2011 Texas Instruments, Inc.
* - OMAP3/4 support by Rajendra Nayak, Santosh Shilimkar
*
* 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.
*/
#include <linux/types.h>
#include <linux/kernel.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/opp.h>
#include <linux/cpu.h>
#include <linux/module.h>
#include <linux/regulator/consumer.h>
#include <asm/smp_plat.h>
#include <asm/cpu.h>
#include <plat/clock.h>
#include <plat/omap-pm.h>
#include <plat/common.h>
#include <plat/omap_device.h>
#include <mach/hardware.h>
/* OPP tolerance in percentage */
#define OPP_TOLERANCE 4
#ifdef CONFIG_SMP
struct lpj_info {
unsigned long ref;
unsigned int freq;
};
static DEFINE_PER_CPU(struct lpj_info, lpj_ref);
static struct lpj_info global_lpj_ref;
#endif
static struct cpufreq_frequency_table *freq_table;
static atomic_t freq_table_users = ATOMIC_INIT(0);
static struct clk *mpu_clk;
static char *mpu_clk_name;
static struct device *mpu_dev;
static struct regulator *mpu_reg;
static int omap_verify_speed(struct cpufreq_policy *policy)
{
if (!freq_table)
return -EINVAL;
return cpufreq_frequency_table_verify(policy, freq_table);
}
static unsigned int omap_getspeed(unsigned int cpu)
{
unsigned long rate;
if (cpu >= NR_CPUS)
return 0;
rate = clk_get_rate(mpu_clk) / 1000;
return rate;
}
static int omap_target(struct cpufreq_policy *policy,
unsigned int target_freq,
unsigned int relation)
{
unsigned int i;
int r, ret = 0;
struct cpufreq_freqs freqs;
struct opp *opp;
unsigned long freq, volt = 0, volt_old = 0, tol = 0;
if (!freq_table) {
dev_err(mpu_dev, "%s: cpu%d: no freq table!\n", __func__,
policy->cpu);
return -EINVAL;
}
ret = cpufreq_frequency_table_target(policy, freq_table, target_freq,
relation, &i);
if (ret) {
dev_dbg(mpu_dev, "%s: cpu%d: no freq match for %d(ret=%d)\n",
__func__, policy->cpu, target_freq, ret);
return ret;
}
freqs.new = freq_table[i].frequency;
if (!freqs.new) {
dev_err(mpu_dev, "%s: cpu%d: no match for freq %d\n", __func__,
policy->cpu, target_freq);
return -EINVAL;
}
freqs.old = omap_getspeed(policy->cpu);
freqs.cpu = policy->cpu;
if (freqs.old == freqs.new && policy->cur == freqs.new)
return ret;
/* notifiers */
for_each_cpu(i, policy->cpus) {
freqs.cpu = i;
cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
}
freq = freqs.new * 1000;
if (mpu_reg) {
opp = opp_find_freq_ceil(mpu_dev, &freq);
if (IS_ERR(opp)) {
dev_err(mpu_dev, "%s: unable to find MPU OPP for %d\n",
__func__, freqs.new);
return -EINVAL;
}
volt = opp_get_voltage(opp);
tol = volt * OPP_TOLERANCE / 100;
volt_old = regulator_get_voltage(mpu_reg);
}
dev_dbg(mpu_dev, "cpufreq-omap: %u MHz, %ld mV --> %u MHz, %ld mV\n",
freqs.old / 1000, volt_old ? volt_old / 1000 : -1,
freqs.new / 1000, volt ? volt / 1000 : -1);
/* scaling up? scale voltage before frequency */
if (mpu_reg && (freqs.new > freqs.old)) {
r = regulator_set_voltage(mpu_reg, volt - tol, volt + tol);
if (r < 0) {
dev_warn(mpu_dev, "%s: unable to scale voltage up.\n",
__func__);
freqs.new = freqs.old;
goto done;
}
}
ret = clk_set_rate(mpu_clk, freqs.new * 1000);
/* scaling down? scale voltage after frequency */
if (mpu_reg && (freqs.new < freqs.old)) {
r = regulator_set_voltage(mpu_reg, volt - tol, volt + tol);
if (r < 0) {
dev_warn(mpu_dev, "%s: unable to scale voltage down.\n",
__func__);
ret = clk_set_rate(mpu_clk, freqs.old * 1000);
freqs.new = freqs.old;
goto done;
}
}
freqs.new = omap_getspeed(policy->cpu);
#ifdef CONFIG_SMP
/*
* Note that loops_per_jiffy is not updated on SMP systems in
* cpufreq driver. So, update the per-CPU loops_per_jiffy value
* on frequency transition. We need to update all dependent CPUs.
*/
for_each_cpu(i, policy->cpus) {
struct lpj_info *lpj = &per_cpu(lpj_ref, i);
if (!lpj->freq) {
lpj->ref = per_cpu(cpu_data, i).loops_per_jiffy;
lpj->freq = freqs.old;
}
per_cpu(cpu_data, i).loops_per_jiffy =
cpufreq_scale(lpj->ref, lpj->freq, freqs.new);
}
/* And don't forget to adjust the global one */
if (!global_lpj_ref.freq) {
global_lpj_ref.ref = loops_per_jiffy;
global_lpj_ref.freq = freqs.old;
}
loops_per_jiffy = cpufreq_scale(global_lpj_ref.ref, global_lpj_ref.freq,
freqs.new);
#endif
done:
/* notifiers */
for_each_cpu(i, policy->cpus) {
freqs.cpu = i;
cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
}
return ret;
}
static inline void freq_table_free(void)
{
if (atomic_dec_and_test(&freq_table_users))
opp_free_cpufreq_table(mpu_dev, &freq_table);
}
static int __cpuinit omap_cpu_init(struct cpufreq_policy *policy)
{
int result = 0;
mpu_clk = clk_get(NULL, mpu_clk_name);
if (IS_ERR(mpu_clk))
return PTR_ERR(mpu_clk);
if (policy->cpu >= NR_CPUS) {
result = -EINVAL;
goto fail_ck;
}
policy->cur = policy->min = policy->max = omap_getspeed(policy->cpu);
if (atomic_inc_return(&freq_table_users) == 1)
result = opp_init_cpufreq_table(mpu_dev, &freq_table);
if (result) {
dev_err(mpu_dev, "%s: cpu%d: failed creating freq table[%d]\n",
__func__, policy->cpu, result);
goto fail_ck;
}
result = cpufreq_frequency_table_cpuinfo(policy, freq_table);
if (result)
goto fail_table;
cpufreq_frequency_table_get_attr(freq_table, policy->cpu);
policy->min = policy->cpuinfo.min_freq;
policy->max = policy->cpuinfo.max_freq;
policy->cur = omap_getspeed(policy->cpu);
/*
* On OMAP SMP configuartion, both processors share the voltage
* and clock. So both CPUs needs to be scaled together and hence
* needs software co-ordination. Use cpufreq affected_cpus
* interface to handle this scenario. Additional is_smp() check
* is to keep SMP_ON_UP build working.
*/
if (is_smp()) {
policy->shared_type = CPUFREQ_SHARED_TYPE_ANY;
cpumask_setall(policy->cpus);
}
/* FIXME: what's the actual transition time? */
policy->cpuinfo.transition_latency = 300 * 1000;
return 0;
fail_table:
freq_table_free();
fail_ck:
clk_put(mpu_clk);
return result;
}
static int omap_cpu_exit(struct cpufreq_policy *policy)
{
freq_table_free();
clk_put(mpu_clk);
return 0;
}
static struct freq_attr *omap_cpufreq_attr[] = {
&cpufreq_freq_attr_scaling_available_freqs,
NULL,
};
static struct cpufreq_driver omap_driver = {
.flags = CPUFREQ_STICKY,
.verify = omap_verify_speed,
.target = omap_target,
.get = omap_getspeed,
.init = omap_cpu_init,
.exit = omap_cpu_exit,
.name = "omap",
.attr = omap_cpufreq_attr,
};
static int __init omap_cpufreq_init(void)
{
if (cpu_is_omap24xx())
mpu_clk_name = "virt_prcm_set";
else if (cpu_is_omap34xx())
mpu_clk_name = "dpll1_ck";
else if (cpu_is_omap44xx())
mpu_clk_name = "dpll_mpu_ck";
if (!mpu_clk_name) {
pr_err("%s: unsupported Silicon?\n", __func__);
return -EINVAL;
}
mpu_dev = omap_device_get_by_hwmod_name("mpu");
if (!mpu_dev) {
pr_warning("%s: unable to get the mpu device\n", __func__);
return -EINVAL;
}
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;
}
}
return cpufreq_register_driver(&omap_driver);
}
static void __exit omap_cpufreq_exit(void)
{
cpufreq_unregister_driver(&omap_driver);
}
MODULE_DESCRIPTION("cpufreq driver for OMAP SoCs");
MODULE_LICENSE("GPL");
module_init(omap_cpufreq_init);
module_exit(omap_cpufreq_exit);