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/*
* Copyright (c) 2010-2011 Samsung Electronics Co., Ltd.
* http://www.samsung.com
*
* EXYNOS4210 - 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/module.h>
#include <linux/kernel.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/cpufreq.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include "exynos-cpufreq.h"
static struct clk *cpu_clk;
static struct clk *moutcore;
static struct clk *mout_mpll;
static struct clk *mout_apll;
static struct exynos_dvfs_info *cpufreq;
static unsigned int exynos4210_volt_table[] = {
1250000, 1150000, 1050000, 975000, 950000,
};
static struct cpufreq_frequency_table exynos4210_freq_table[] = {
{0, L0, 1200 * 1000},
{0, L1, 1000 * 1000},
{0, L2, 800 * 1000},
{0, L3, 500 * 1000},
{0, L4, 200 * 1000},
{0, 0, CPUFREQ_TABLE_END},
};
static struct apll_freq apll_freq_4210[] = {
/*
* values:
* freq
* clock divider for CORE, COREM0, COREM1, PERIPH, ATB, PCLK_DBG, APLL, RESERVED
* clock divider for COPY, HPM, RESERVED
* PLL M, P, S
*/
APLL_FREQ(1200, 0, 3, 7, 3, 4, 1, 7, 0, 5, 0, 0, 150, 3, 1),
APLL_FREQ(1000, 0, 3, 7, 3, 4, 1, 7, 0, 4, 0, 0, 250, 6, 1),
APLL_FREQ(800, 0, 3, 7, 3, 3, 1, 7, 0, 3, 0, 0, 200, 6, 1),
APLL_FREQ(500, 0, 3, 7, 3, 3, 1, 7, 0, 3, 0, 0, 250, 6, 2),
APLL_FREQ(200, 0, 1, 3, 1, 3, 1, 0, 0, 3, 0, 0, 200, 6, 3),
};
static void exynos4210_set_clkdiv(unsigned int div_index)
{
unsigned int tmp;
/* Change Divider - CPU0 */
tmp = apll_freq_4210[div_index].clk_div_cpu0;
__raw_writel(tmp, cpufreq->cmu_regs + EXYNOS4_CLKDIV_CPU);
do {
tmp = __raw_readl(cpufreq->cmu_regs + EXYNOS4_CLKDIV_STATCPU);
} while (tmp & 0x1111111);
/* Change Divider - CPU1 */
tmp = apll_freq_4210[div_index].clk_div_cpu1;
__raw_writel(tmp, cpufreq->cmu_regs + EXYNOS4_CLKDIV_CPU1);
do {
tmp = __raw_readl(cpufreq->cmu_regs + EXYNOS4_CLKDIV_STATCPU1);
} while (tmp & 0x11);
}
static void exynos4210_set_apll(unsigned int index)
{
unsigned int tmp, freq = apll_freq_4210[index].freq;
/* MUX_CORE_SEL = MPLL, ARMCLK uses MPLL for lock time */
clk_set_parent(moutcore, mout_mpll);
do {
tmp = (__raw_readl(cpufreq->cmu_regs + EXYNOS4_CLKMUX_STATCPU)
>> EXYNOS4_CLKSRC_CPU_MUXCORE_SHIFT);
tmp &= 0x7;
} while (tmp != 0x2);
clk_set_rate(mout_apll, freq * 1000);
/* MUX_CORE_SEL = APLL */
clk_set_parent(moutcore, mout_apll);
do {
tmp = __raw_readl(cpufreq->cmu_regs + EXYNOS4_CLKMUX_STATCPU);
tmp &= EXYNOS4_CLKMUX_STATCPU_MUXCORE_MASK;
} while (tmp != (0x1 << EXYNOS4_CLKSRC_CPU_MUXCORE_SHIFT));
}
static void exynos4210_set_frequency(unsigned int old_index,
unsigned int new_index)
{
if (old_index > new_index) {
exynos4210_set_clkdiv(new_index);
exynos4210_set_apll(new_index);
} else if (old_index < new_index) {
exynos4210_set_apll(new_index);
exynos4210_set_clkdiv(new_index);
}
}
int exynos4210_cpufreq_init(struct exynos_dvfs_info *info)
{
struct device_node *np;
unsigned long rate;
/*
* HACK: This is a temporary workaround to get access to clock
* controller registers directly and remove static mappings and
* dependencies on platform headers. It is necessary to enable
* Exynos multi-platform support and will be removed together with
* this whole driver as soon as Exynos gets migrated to use
* cpufreq-cpu0 driver.
*/
np = of_find_compatible_node(NULL, NULL, "samsung,exynos4210-clock");
if (!np) {
pr_err("%s: failed to find clock controller DT node\n",
__func__);
return -ENODEV;
}
info->cmu_regs = of_iomap(np, 0);
if (!info->cmu_regs) {
pr_err("%s: failed to map CMU registers\n", __func__);
return -EFAULT;
}
cpu_clk = clk_get(NULL, "armclk");
if (IS_ERR(cpu_clk))
return PTR_ERR(cpu_clk);
moutcore = clk_get(NULL, "moutcore");
if (IS_ERR(moutcore))
goto err_moutcore;
mout_mpll = clk_get(NULL, "mout_mpll");
if (IS_ERR(mout_mpll))
goto err_mout_mpll;
rate = clk_get_rate(mout_mpll) / 1000;
mout_apll = clk_get(NULL, "mout_apll");
if (IS_ERR(mout_apll))
goto err_mout_apll;
info->mpll_freq_khz = rate;
/* 800Mhz */
info->pll_safe_idx = L2;
info->cpu_clk = cpu_clk;
info->volt_table = exynos4210_volt_table;
info->freq_table = exynos4210_freq_table;
info->set_freq = exynos4210_set_frequency;
cpufreq = info;
return 0;
err_mout_apll:
clk_put(mout_mpll);
err_mout_mpll:
clk_put(moutcore);
err_moutcore:
clk_put(cpu_clk);
pr_debug("%s: failed initialization\n", __func__);
return -EINVAL;
}
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