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linux/drivers/cpufreq/exynos4210-cpufreq.c
MyungJoo Ham 0073f538c1 [CPUFREQ] ARM Exynos4210 PM/Suspend compatibility with different bootloaders 
We have various bootloaders for Exynos4210 machines. Some of they
set the ARM core frequency at boot time even when the boot is a resume
from suspend-to-RAM. Such changes may create inconsistency in the
data of CPUFREQ driver and have incurred hang issues with suspend-to-RAM.

This patch enables to save and restore CPU frequencies with pm-notifier and
sets the frequency at the initial (boot-time) value so that there wouldn't
be any inconsistency between bootloader and kernel. This patch does not
use CPUFREQ's suspend/resume callbacks because they are syscore-ops, which
do not allow to use mutex that is being used by regulators that are used by
the target function.

This also prevents any CPUFREQ transitions during suspend-resume context,
which could be dangerous at noirq-context along with regulator framework.

Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Dave Jones <davej@redhat.com>
2011-10-26 17:19:46 -04:00

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/*
* Copyright (c) 2010-2011 Samsung Electronics Co., Ltd.
* http://www.samsung.com
*
* EXYNOS4 - CPU frequency scaling support
*
* 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/err.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/regulator/consumer.h>
#include <linux/cpufreq.h>
#include <linux/notifier.h>
#include <linux/suspend.h>
#include <mach/map.h>
#include <mach/regs-clock.h>
#include <mach/regs-mem.h>
#include <plat/clock.h>
#include <plat/pm.h>
static struct clk *cpu_clk;
static struct clk *moutcore;
static struct clk *mout_mpll;
static struct clk *mout_apll;
static struct regulator *arm_regulator;
static struct regulator *int_regulator;
static struct cpufreq_freqs freqs;
static unsigned int memtype;
static unsigned int locking_frequency;
static bool frequency_locked;
static DEFINE_MUTEX(cpufreq_lock);
enum exynos4_memory_type {
DDR2 = 4,
LPDDR2,
DDR3,
};
enum cpufreq_level_index {
L0, L1, L2, L3, CPUFREQ_LEVEL_END,
};
static struct cpufreq_frequency_table exynos4_freq_table[] = {
{L0, 1000*1000},
{L1, 800*1000},
{L2, 400*1000},
{L3, 100*1000},
{0, CPUFREQ_TABLE_END},
};
static unsigned int clkdiv_cpu0[CPUFREQ_LEVEL_END][7] = {
/*
* Clock divider value for following
* { DIVCORE, DIVCOREM0, DIVCOREM1, DIVPERIPH,
* DIVATB, DIVPCLK_DBG, DIVAPLL }
*/
/* ARM L0: 1000MHz */
{ 0, 3, 7, 3, 3, 0, 1 },
/* ARM L1: 800MHz */
{ 0, 3, 7, 3, 3, 0, 1 },
/* ARM L2: 400MHz */
{ 0, 1, 3, 1, 3, 0, 1 },
/* ARM L3: 100MHz */
{ 0, 0, 1, 0, 3, 1, 1 },
};
static unsigned int clkdiv_cpu1[CPUFREQ_LEVEL_END][2] = {
/*
* Clock divider value for following
* { DIVCOPY, DIVHPM }
*/
/* ARM L0: 1000MHz */
{ 3, 0 },
/* ARM L1: 800MHz */
{ 3, 0 },
/* ARM L2: 400MHz */
{ 3, 0 },
/* ARM L3: 100MHz */
{ 3, 0 },
};
static unsigned int clkdiv_dmc0[CPUFREQ_LEVEL_END][8] = {
/*
* Clock divider value for following
* { DIVACP, DIVACP_PCLK, DIVDPHY, DIVDMC, DIVDMCD
* DIVDMCP, DIVCOPY2, DIVCORE_TIMERS }
*/
/* DMC L0: 400MHz */
{ 3, 1, 1, 1, 1, 1, 3, 1 },
/* DMC L1: 400MHz */
{ 3, 1, 1, 1, 1, 1, 3, 1 },
/* DMC L2: 266.7MHz */
{ 7, 1, 1, 2, 1, 1, 3, 1 },
/* DMC L3: 200MHz */
{ 7, 1, 1, 3, 1, 1, 3, 1 },
};
static unsigned int clkdiv_top[CPUFREQ_LEVEL_END][5] = {
/*
* Clock divider value for following
* { DIVACLK200, DIVACLK100, DIVACLK160, DIVACLK133, DIVONENAND }
*/
/* ACLK200 L0: 200MHz */
{ 3, 7, 4, 5, 1 },
/* ACLK200 L1: 200MHz */
{ 3, 7, 4, 5, 1 },
/* ACLK200 L2: 160MHz */
{ 4, 7, 5, 7, 1 },
/* ACLK200 L3: 133.3MHz */
{ 5, 7, 7, 7, 1 },
};
static unsigned int clkdiv_lr_bus[CPUFREQ_LEVEL_END][2] = {
/*
* Clock divider value for following
* { DIVGDL/R, DIVGPL/R }
*/
/* ACLK_GDL/R L0: 200MHz */
{ 3, 1 },
/* ACLK_GDL/R L1: 200MHz */
{ 3, 1 },
/* ACLK_GDL/R L2: 160MHz */
{ 4, 1 },
/* ACLK_GDL/R L3: 133.3MHz */
{ 5, 1 },
};
struct cpufreq_voltage_table {
unsigned int index; /* any */
unsigned int arm_volt; /* uV */
unsigned int int_volt;
};
static struct cpufreq_voltage_table exynos4_volt_table[CPUFREQ_LEVEL_END] = {
{
.index = L0,
.arm_volt = 1200000,
.int_volt = 1100000,
}, {
.index = L1,
.arm_volt = 1100000,
.int_volt = 1100000,
}, {
.index = L2,
.arm_volt = 1000000,
.int_volt = 1000000,
}, {
.index = L3,
.arm_volt = 900000,
.int_volt = 1000000,
},
};
static unsigned int exynos4_apll_pms_table[CPUFREQ_LEVEL_END] = {
/* APLL FOUT L0: 1000MHz */
((250 << 16) | (6 << 8) | 1),
/* APLL FOUT L1: 800MHz */
((200 << 16) | (6 << 8) | 1),
/* APLL FOUT L2 : 400MHz */
((200 << 16) | (6 << 8) | 2),
/* APLL FOUT L3: 100MHz */
((200 << 16) | (6 << 8) | 4),
};
static int exynos4_verify_speed(struct cpufreq_policy *policy)
{
return cpufreq_frequency_table_verify(policy, exynos4_freq_table);
}
static unsigned int exynos4_getspeed(unsigned int cpu)
{
return clk_get_rate(cpu_clk) / 1000;
}
static void exynos4_set_clkdiv(unsigned int div_index)
{
unsigned int tmp;
/* Change Divider - CPU0 */
tmp = __raw_readl(S5P_CLKDIV_CPU);
tmp &= ~(S5P_CLKDIV_CPU0_CORE_MASK | S5P_CLKDIV_CPU0_COREM0_MASK |
S5P_CLKDIV_CPU0_COREM1_MASK | S5P_CLKDIV_CPU0_PERIPH_MASK |
S5P_CLKDIV_CPU0_ATB_MASK | S5P_CLKDIV_CPU0_PCLKDBG_MASK |
S5P_CLKDIV_CPU0_APLL_MASK);
tmp |= ((clkdiv_cpu0[div_index][0] << S5P_CLKDIV_CPU0_CORE_SHIFT) |
(clkdiv_cpu0[div_index][1] << S5P_CLKDIV_CPU0_COREM0_SHIFT) |
(clkdiv_cpu0[div_index][2] << S5P_CLKDIV_CPU0_COREM1_SHIFT) |
(clkdiv_cpu0[div_index][3] << S5P_CLKDIV_CPU0_PERIPH_SHIFT) |
(clkdiv_cpu0[div_index][4] << S5P_CLKDIV_CPU0_ATB_SHIFT) |
(clkdiv_cpu0[div_index][5] << S5P_CLKDIV_CPU0_PCLKDBG_SHIFT) |
(clkdiv_cpu0[div_index][6] << S5P_CLKDIV_CPU0_APLL_SHIFT));
__raw_writel(tmp, S5P_CLKDIV_CPU);
do {
tmp = __raw_readl(S5P_CLKDIV_STATCPU);
} while (tmp & 0x1111111);
/* Change Divider - CPU1 */
tmp = __raw_readl(S5P_CLKDIV_CPU1);
tmp &= ~((0x7 << 4) | 0x7);
tmp |= ((clkdiv_cpu1[div_index][0] << 4) |
(clkdiv_cpu1[div_index][1] << 0));
__raw_writel(tmp, S5P_CLKDIV_CPU1);
do {
tmp = __raw_readl(S5P_CLKDIV_STATCPU1);
} while (tmp & 0x11);
/* Change Divider - DMC0 */
tmp = __raw_readl(S5P_CLKDIV_DMC0);
tmp &= ~(S5P_CLKDIV_DMC0_ACP_MASK | S5P_CLKDIV_DMC0_ACPPCLK_MASK |
S5P_CLKDIV_DMC0_DPHY_MASK | S5P_CLKDIV_DMC0_DMC_MASK |
S5P_CLKDIV_DMC0_DMCD_MASK | S5P_CLKDIV_DMC0_DMCP_MASK |
S5P_CLKDIV_DMC0_COPY2_MASK | S5P_CLKDIV_DMC0_CORETI_MASK);
tmp |= ((clkdiv_dmc0[div_index][0] << S5P_CLKDIV_DMC0_ACP_SHIFT) |
(clkdiv_dmc0[div_index][1] << S5P_CLKDIV_DMC0_ACPPCLK_SHIFT) |
(clkdiv_dmc0[div_index][2] << S5P_CLKDIV_DMC0_DPHY_SHIFT) |
(clkdiv_dmc0[div_index][3] << S5P_CLKDIV_DMC0_DMC_SHIFT) |
(clkdiv_dmc0[div_index][4] << S5P_CLKDIV_DMC0_DMCD_SHIFT) |
(clkdiv_dmc0[div_index][5] << S5P_CLKDIV_DMC0_DMCP_SHIFT) |
(clkdiv_dmc0[div_index][6] << S5P_CLKDIV_DMC0_COPY2_SHIFT) |
(clkdiv_dmc0[div_index][7] << S5P_CLKDIV_DMC0_CORETI_SHIFT));
__raw_writel(tmp, S5P_CLKDIV_DMC0);
do {
tmp = __raw_readl(S5P_CLKDIV_STAT_DMC0);
} while (tmp & 0x11111111);
/* Change Divider - TOP */
tmp = __raw_readl(S5P_CLKDIV_TOP);
tmp &= ~(S5P_CLKDIV_TOP_ACLK200_MASK | S5P_CLKDIV_TOP_ACLK100_MASK |
S5P_CLKDIV_TOP_ACLK160_MASK | S5P_CLKDIV_TOP_ACLK133_MASK |
S5P_CLKDIV_TOP_ONENAND_MASK);
tmp |= ((clkdiv_top[div_index][0] << S5P_CLKDIV_TOP_ACLK200_SHIFT) |
(clkdiv_top[div_index][1] << S5P_CLKDIV_TOP_ACLK100_SHIFT) |
(clkdiv_top[div_index][2] << S5P_CLKDIV_TOP_ACLK160_SHIFT) |
(clkdiv_top[div_index][3] << S5P_CLKDIV_TOP_ACLK133_SHIFT) |
(clkdiv_top[div_index][4] << S5P_CLKDIV_TOP_ONENAND_SHIFT));
__raw_writel(tmp, S5P_CLKDIV_TOP);
do {
tmp = __raw_readl(S5P_CLKDIV_STAT_TOP);
} while (tmp & 0x11111);
/* Change Divider - LEFTBUS */
tmp = __raw_readl(S5P_CLKDIV_LEFTBUS);
tmp &= ~(S5P_CLKDIV_BUS_GDLR_MASK | S5P_CLKDIV_BUS_GPLR_MASK);
tmp |= ((clkdiv_lr_bus[div_index][0] << S5P_CLKDIV_BUS_GDLR_SHIFT) |
(clkdiv_lr_bus[div_index][1] << S5P_CLKDIV_BUS_GPLR_SHIFT));
__raw_writel(tmp, S5P_CLKDIV_LEFTBUS);
do {
tmp = __raw_readl(S5P_CLKDIV_STAT_LEFTBUS);
} while (tmp & 0x11);
/* Change Divider - RIGHTBUS */
tmp = __raw_readl(S5P_CLKDIV_RIGHTBUS);
tmp &= ~(S5P_CLKDIV_BUS_GDLR_MASK | S5P_CLKDIV_BUS_GPLR_MASK);
tmp |= ((clkdiv_lr_bus[div_index][0] << S5P_CLKDIV_BUS_GDLR_SHIFT) |
(clkdiv_lr_bus[div_index][1] << S5P_CLKDIV_BUS_GPLR_SHIFT));
__raw_writel(tmp, S5P_CLKDIV_RIGHTBUS);
do {
tmp = __raw_readl(S5P_CLKDIV_STAT_RIGHTBUS);
} while (tmp & 0x11);
}
static void exynos4_set_apll(unsigned int index)
{
unsigned int tmp;
/* 1. MUX_CORE_SEL = MPLL, ARMCLK uses MPLL for lock time */
clk_set_parent(moutcore, mout_mpll);
do {
tmp = (__raw_readl(S5P_CLKMUX_STATCPU)
>> S5P_CLKSRC_CPU_MUXCORE_SHIFT);
tmp &= 0x7;
} while (tmp != 0x2);
/* 2. Set APLL Lock time */
__raw_writel(S5P_APLL_LOCKTIME, S5P_APLL_LOCK);
/* 3. Change PLL PMS values */
tmp = __raw_readl(S5P_APLL_CON0);
tmp &= ~((0x3ff << 16) | (0x3f << 8) | (0x7 << 0));
tmp |= exynos4_apll_pms_table[index];
__raw_writel(tmp, S5P_APLL_CON0);
/* 4. wait_lock_time */
do {
tmp = __raw_readl(S5P_APLL_CON0);
} while (!(tmp & (0x1 << S5P_APLLCON0_LOCKED_SHIFT)));
/* 5. MUX_CORE_SEL = APLL */
clk_set_parent(moutcore, mout_apll);
do {
tmp = __raw_readl(S5P_CLKMUX_STATCPU);
tmp &= S5P_CLKMUX_STATCPU_MUXCORE_MASK;
} while (tmp != (0x1 << S5P_CLKSRC_CPU_MUXCORE_SHIFT));
}
static void exynos4_set_frequency(unsigned int old_index, unsigned int new_index)
{
unsigned int tmp;
if (old_index > new_index) {
/* The frequency changing to L0 needs to change apll */
if (freqs.new == exynos4_freq_table[L0].frequency) {
/* 1. Change the system clock divider values */
exynos4_set_clkdiv(new_index);
/* 2. Change the apll m,p,s value */
exynos4_set_apll(new_index);
} else {
/* 1. Change the system clock divider values */
exynos4_set_clkdiv(new_index);
/* 2. Change just s value in apll m,p,s value */
tmp = __raw_readl(S5P_APLL_CON0);
tmp &= ~(0x7 << 0);
tmp |= (exynos4_apll_pms_table[new_index] & 0x7);
__raw_writel(tmp, S5P_APLL_CON0);
}
}
else if (old_index < new_index) {
/* The frequency changing from L0 needs to change apll */
if (freqs.old == exynos4_freq_table[L0].frequency) {
/* 1. Change the apll m,p,s value */
exynos4_set_apll(new_index);
/* 2. Change the system clock divider values */
exynos4_set_clkdiv(new_index);
} else {
/* 1. Change just s value in apll m,p,s value */
tmp = __raw_readl(S5P_APLL_CON0);
tmp &= ~(0x7 << 0);
tmp |= (exynos4_apll_pms_table[new_index] & 0x7);
__raw_writel(tmp, S5P_APLL_CON0);
/* 2. Change the system clock divider values */
exynos4_set_clkdiv(new_index);
}
}
}
static int exynos4_target(struct cpufreq_policy *policy,
unsigned int target_freq,
unsigned int relation)
{
unsigned int index, old_index;
unsigned int arm_volt, int_volt;
int err = -EINVAL;
freqs.old = exynos4_getspeed(policy->cpu);
mutex_lock(&cpufreq_lock);
if (frequency_locked && target_freq != locking_frequency) {
err = -EAGAIN;
goto out;
}
if (cpufreq_frequency_table_target(policy, exynos4_freq_table,
freqs.old, relation, &old_index))
goto out;
if (cpufreq_frequency_table_target(policy, exynos4_freq_table,
target_freq, relation, &index))
goto out;
err = 0;
freqs.new = exynos4_freq_table[index].frequency;
freqs.cpu = policy->cpu;
if (freqs.new == freqs.old)
goto out;
/* get the voltage value */
arm_volt = exynos4_volt_table[index].arm_volt;
int_volt = exynos4_volt_table[index].int_volt;
cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
/* control regulator */
if (freqs.new > freqs.old) {
/* Voltage up */
regulator_set_voltage(arm_regulator, arm_volt, arm_volt);
regulator_set_voltage(int_regulator, int_volt, int_volt);
}
/* Clock Configuration Procedure */
exynos4_set_frequency(old_index, index);
/* control regulator */
if (freqs.new < freqs.old) {
/* Voltage down */
regulator_set_voltage(arm_regulator, arm_volt, arm_volt);
regulator_set_voltage(int_regulator, int_volt, int_volt);
}
cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
out:
mutex_unlock(&cpufreq_lock);
return err;
}
#ifdef CONFIG_PM
/*
* These suspend/resume are used as syscore_ops, it is already too
* late to set regulator voltages at this stage.
*/
static int exynos4_cpufreq_suspend(struct cpufreq_policy *policy)
{
return 0;
}
static int exynos4_cpufreq_resume(struct cpufreq_policy *policy)
{
return 0;
}
#endif
/**
* exynos4_cpufreq_pm_notifier - block CPUFREQ's activities in suspend-resume
* context
* @notifier
* @pm_event
* @v
*
* While frequency_locked == true, target() ignores every frequency but
* locking_frequency. The locking_frequency value is the initial frequency,
* which is set by the bootloader. In order to eliminate possible
* inconsistency in clock values, we save and restore frequencies during
* suspend and resume and block CPUFREQ activities. Note that the standard
* suspend/resume cannot be used as they are too deep (syscore_ops) for
* regulator actions.
*/
static int exynos4_cpufreq_pm_notifier(struct notifier_block *notifier,
unsigned long pm_event, void *v)
{
struct cpufreq_policy *policy = cpufreq_cpu_get(0); /* boot CPU */
static unsigned int saved_frequency;
unsigned int temp;
mutex_lock(&cpufreq_lock);
switch (pm_event) {
case PM_SUSPEND_PREPARE:
if (frequency_locked)
goto out;
frequency_locked = true;
if (locking_frequency) {
saved_frequency = exynos4_getspeed(0);
mutex_unlock(&cpufreq_lock);
exynos4_target(policy, locking_frequency,
CPUFREQ_RELATION_H);
mutex_lock(&cpufreq_lock);
}
break;
case PM_POST_SUSPEND:
if (saved_frequency) {
/*
* While frequency_locked, only locking_frequency
* is valid for target(). In order to use
* saved_frequency while keeping frequency_locked,
* we temporarly overwrite locking_frequency.
*/
temp = locking_frequency;
locking_frequency = saved_frequency;
mutex_unlock(&cpufreq_lock);
exynos4_target(policy, locking_frequency,
CPUFREQ_RELATION_H);
mutex_lock(&cpufreq_lock);
locking_frequency = temp;
}
frequency_locked = false;
break;
}
out:
mutex_unlock(&cpufreq_lock);
return NOTIFY_OK;
}
static struct notifier_block exynos4_cpufreq_nb = {
.notifier_call = exynos4_cpufreq_pm_notifier,
};
static int exynos4_cpufreq_cpu_init(struct cpufreq_policy *policy)
{
int ret;
policy->cur = policy->min = policy->max = exynos4_getspeed(policy->cpu);
cpufreq_frequency_table_get_attr(exynos4_freq_table, policy->cpu);
/* set the transition latency value */
policy->cpuinfo.transition_latency = 100000;
/*
* EXYNOS4 multi-core processors has 2 cores
* that the frequency cannot be set independently.
* Each cpu is bound to the same speed.
* So the affected cpu is all of the cpus.
*/
cpumask_setall(policy->cpus);
ret = cpufreq_frequency_table_cpuinfo(policy, exynos4_freq_table);
if (ret)
return ret;
cpufreq_frequency_table_get_attr(exynos4_freq_table, policy->cpu);
return 0;
}
static int exynos4_cpufreq_cpu_exit(struct cpufreq_policy *policy)
{
cpufreq_frequency_table_put_attr(policy->cpu);
return 0;
}
static struct freq_attr *exynos4_cpufreq_attr[] = {
&cpufreq_freq_attr_scaling_available_freqs,
NULL,
};
static struct cpufreq_driver exynos4_driver = {
.flags = CPUFREQ_STICKY,
.verify = exynos4_verify_speed,
.target = exynos4_target,
.get = exynos4_getspeed,
.init = exynos4_cpufreq_cpu_init,
.exit = exynos4_cpufreq_cpu_exit,
.name = "exynos4_cpufreq",
.attr = exynos4_cpufreq_attr,
#ifdef CONFIG_PM
.suspend = exynos4_cpufreq_suspend,
.resume = exynos4_cpufreq_resume,
#endif
};
static int __init exynos4_cpufreq_init(void)
{
cpu_clk = clk_get(NULL, "armclk");
if (IS_ERR(cpu_clk))
return PTR_ERR(cpu_clk);
locking_frequency = exynos4_getspeed(0);
moutcore = clk_get(NULL, "moutcore");
if (IS_ERR(moutcore))
goto out;
mout_mpll = clk_get(NULL, "mout_mpll");
if (IS_ERR(mout_mpll))
goto out;
mout_apll = clk_get(NULL, "mout_apll");
if (IS_ERR(mout_apll))
goto out;
arm_regulator = regulator_get(NULL, "vdd_arm");
if (IS_ERR(arm_regulator)) {
printk(KERN_ERR "failed to get resource %s\n", "vdd_arm");
goto out;
}
int_regulator = regulator_get(NULL, "vdd_int");
if (IS_ERR(int_regulator)) {
printk(KERN_ERR "failed to get resource %s\n", "vdd_int");
goto out;
}
/*
* Check DRAM type.
* Because DVFS level is different according to DRAM type.
*/
memtype = __raw_readl(S5P_VA_DMC0 + S5P_DMC0_MEMCON_OFFSET);
memtype = (memtype >> S5P_DMC0_MEMTYPE_SHIFT);
memtype &= S5P_DMC0_MEMTYPE_MASK;
if ((memtype < DDR2) && (memtype > DDR3)) {
printk(KERN_ERR "%s: wrong memtype= 0x%x\n", __func__, memtype);
goto out;
} else {
printk(KERN_DEBUG "%s: memtype= 0x%x\n", __func__, memtype);
}
register_pm_notifier(&exynos4_cpufreq_nb);
return cpufreq_register_driver(&exynos4_driver);
out:
if (!IS_ERR(cpu_clk))
clk_put(cpu_clk);
if (!IS_ERR(moutcore))
clk_put(moutcore);
if (!IS_ERR(mout_mpll))
clk_put(mout_mpll);
if (!IS_ERR(mout_apll))
clk_put(mout_apll);
if (!IS_ERR(arm_regulator))
regulator_put(arm_regulator);
if (!IS_ERR(int_regulator))
regulator_put(int_regulator);
printk(KERN_ERR "%s: failed initialization\n", __func__);
return -EINVAL;
}
late_initcall(exynos4_cpufreq_init);
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