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/*
 * Copyright (c) 2010-20122Samsung Electronics Co., Ltd.
 *		http://www.samsung.com
 *
 * EXYNOS5250 - 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 <mach/map.h>
#include <mach/regs-clock.h>
#include <mach/cpufreq.h>

#define CPUFREQ_LEVEL_END	(L15 + 1)

static int max_support_idx;
static int min_support_idx = (CPUFREQ_LEVEL_END - 1);
static struct clk *cpu_clk;
static struct clk *moutcore;
static struct clk *mout_mpll;
static struct clk *mout_apll;

struct cpufreq_clkdiv {
	unsigned int	index;
	unsigned int	clkdiv;
	unsigned int	clkdiv1;
};

static unsigned int exynos5250_volt_table[CPUFREQ_LEVEL_END];

static struct cpufreq_frequency_table exynos5250_freq_table[] = {
	{L0, 1700 * 1000},
	{L1, 1600 * 1000},
	{L2, 1500 * 1000},
	{L3, 1400 * 1000},
	{L4, 1300 * 1000},
	{L5, 1200 * 1000},
	{L6, 1100 * 1000},
	{L7, 1000 * 1000},
	{L8, 900 * 1000},
	{L9, 800 * 1000},
	{L10, 700 * 1000},
	{L11, 600 * 1000},
	{L12, 500 * 1000},
	{L13, 400 * 1000},
	{L14, 300 * 1000},
	{L15, 200 * 1000},
	{0, CPUFREQ_TABLE_END},
};

static struct cpufreq_clkdiv exynos5250_clkdiv_table[CPUFREQ_LEVEL_END];

static unsigned int clkdiv_cpu0_5250[CPUFREQ_LEVEL_END][8] = {
	/*
	 * Clock divider value for following
	 * { ARM, CPUD, ACP, PERIPH, ATB, PCLK_DBG, APLL, ARM2 }
	 */
	{ 0, 3, 7, 7, 6, 1, 3, 0 },	/* 1700 MHz - N/A */
	{ 0, 3, 7, 7, 6, 1, 3, 0 },	/* 1600 MHz - N/A */
	{ 0, 3, 7, 7, 5, 1, 3, 0 },	/* 1500 MHz - N/A */
	{ 0, 3, 7, 7, 6, 1, 3, 0 },	/* 1400 MHz */
	{ 0, 3, 7, 7, 6, 1, 3, 0 },	/* 1300 MHz */
	{ 0, 3, 7, 7, 5, 1, 3, 0 },	/* 1200 MHz */
	{ 0, 2, 7, 7, 5, 1, 2, 0 },	/* 1100 MHz */
	{ 0, 2, 7, 7, 4, 1, 2, 0 },	/* 1000 MHz */
	{ 0, 2, 7, 7, 4, 1, 2, 0 },	/* 900 MHz */
	{ 0, 2, 7, 7, 3, 1, 1, 0 },	/* 800 MHz */
	{ 0, 1, 7, 7, 3, 1, 1, 0 },	/* 700 MHz */
	{ 0, 1, 7, 7, 2, 1, 1, 0 },	/* 600 MHz */
	{ 0, 1, 7, 7, 2, 1, 1, 0 },	/* 500 MHz */
	{ 0, 1, 7, 7, 1, 1, 1, 0 },	/* 400 MHz */
	{ 0, 1, 7, 7, 1, 1, 1, 0 },	/* 300 MHz */
	{ 0, 1, 7, 7, 1, 1, 1, 0 },	/* 200 MHz */
};

static unsigned int clkdiv_cpu1_5250[CPUFREQ_LEVEL_END][2] = {
	/* Clock divider value for following
	 * { COPY, HPM }
	 */
	{ 0, 2 },	/* 1700 MHz - N/A */
	{ 0, 2 },	/* 1600 MHz - N/A */
	{ 0, 2 },	/* 1500 MHz - N/A */
	{ 0, 2 },	/* 1400 MHz */
	{ 0, 2 },	/* 1300 MHz */
	{ 0, 2 },	/* 1200 MHz */
	{ 0, 2 },	/* 1100 MHz */
	{ 0, 2 },	/* 1000 MHz */
	{ 0, 2 },	/* 900 MHz */
	{ 0, 2 },	/* 800 MHz */
	{ 0, 2 },	/* 700 MHz */
	{ 0, 2 },	/* 600 MHz */
	{ 0, 2 },	/* 500 MHz */
	{ 0, 2 },	/* 400 MHz */
	{ 0, 2 },	/* 300 MHz */
	{ 0, 2 },	/* 200 MHz */
};

static unsigned int exynos5_apll_pms_table[CPUFREQ_LEVEL_END] = {
	(0),				/* 1700 MHz - N/A */
	(0),				/* 1600 MHz - N/A */
	(0),				/* 1500 MHz - N/A */
	(0),				/* 1400 MHz */
	((325 << 16) | (6 << 8) | 0),	/* 1300 MHz */
	((200 << 16) | (4 << 8) | 0),	/* 1200 MHz */
	((275 << 16) | (6 << 8) | 0),	/* 1100 MHz */
	((125 << 16) | (3 << 8) | 0),	/* 1000 MHz */
	((150 << 16) | (4 << 8) | 0),	/* 900 MHz */
	((100 << 16) | (3 << 8) | 0),	/* 800 MHz */
	((175 << 16) | (3 << 8) | 1),	/* 700 MHz */
	((200 << 16) | (4 << 8) | 1),	/* 600 MHz */
	((125 << 16) | (3 << 8) | 1),	/* 500 MHz */
	((100 << 16) | (3 << 8) | 1),	/* 400 MHz */
	((200 << 16) | (4 << 8) | 2),	/* 300 MHz */
	((100 << 16) | (3 << 8) | 2),	/* 200 MHz */
};

/* ASV group voltage table */
static const unsigned int asv_voltage_5250[CPUFREQ_LEVEL_END] = {
	0, 0, 0, 0, 0, 0, 0,	/* 1700 MHz ~ 1100 MHz Not supported */
	1175000, 1125000, 1075000, 1050000, 1000000,
	950000, 925000, 925000, 900000
};

static void set_clkdiv(unsigned int div_index)
{
	unsigned int tmp;

	/* Change Divider - CPU0 */

	tmp = exynos5250_clkdiv_table[div_index].clkdiv;

	__raw_writel(tmp, EXYNOS5_CLKDIV_CPU0);

	while (__raw_readl(EXYNOS5_CLKDIV_STATCPU0) & 0x11111111)
		cpu_relax();

	/* Change Divider - CPU1 */
	tmp = exynos5250_clkdiv_table[div_index].clkdiv1;

	__raw_writel(tmp, EXYNOS5_CLKDIV_CPU1);

	while (__raw_readl(EXYNOS5_CLKDIV_STATCPU1) & 0x11)
		cpu_relax();
}

static void set_apll(unsigned int new_index,
			     unsigned int old_index)
{
	unsigned int tmp, pdiv;

	/* 1. MUX_CORE_SEL = MPLL, ARMCLK uses MPLL for lock time */
	clk_set_parent(moutcore, mout_mpll);

	do {
		cpu_relax();
		tmp = (__raw_readl(EXYNOS5_CLKMUX_STATCPU) >> 16);
		tmp &= 0x7;
	} while (tmp != 0x2);

	/* 2. Set APLL Lock time */
	pdiv = ((exynos5_apll_pms_table[new_index] >> 8) & 0x3f);

	__raw_writel((pdiv * 250), EXYNOS5_APLL_LOCK);

	/* 3. Change PLL PMS values */
	tmp = __raw_readl(EXYNOS5_APLL_CON0);
	tmp &= ~((0x3ff << 16) | (0x3f << 8) | (0x7 << 0));
	tmp |= exynos5_apll_pms_table[new_index];
	__raw_writel(tmp, EXYNOS5_APLL_CON0);

	/* 4. wait_lock_time */
	do {
		cpu_relax();
		tmp = __raw_readl(EXYNOS5_APLL_CON0);
	} while (!(tmp & (0x1 << 29)));

	/* 5. MUX_CORE_SEL = APLL */
	clk_set_parent(moutcore, mout_apll);

	do {
		cpu_relax();
		tmp = __raw_readl(EXYNOS5_CLKMUX_STATCPU);
		tmp &= (0x7 << 16);
	} while (tmp != (0x1 << 16));

}

bool exynos5250_pms_change(unsigned int old_index, unsigned int new_index)
{
	unsigned int old_pm = (exynos5_apll_pms_table[old_index] >> 8);
	unsigned int new_pm = (exynos5_apll_pms_table[new_index] >> 8);

	return (old_pm == new_pm) ? 0 : 1;
}

static void exynos5250_set_frequency(unsigned int old_index,
				  unsigned int new_index)
{
	unsigned int tmp;

	if (old_index > new_index) {
		if (!exynos5250_pms_change(old_index, new_index)) {
			/* 1. Change the system clock divider values */
			set_clkdiv(new_index);
			/* 2. Change just s value in apll m,p,s value */
			tmp = __raw_readl(EXYNOS5_APLL_CON0);
			tmp &= ~(0x7 << 0);
			tmp |= (exynos5_apll_pms_table[new_index] & 0x7);
			__raw_writel(tmp, EXYNOS5_APLL_CON0);

		} else {
			/* Clock Configuration Procedure */
			/* 1. Change the system clock divider values */
			set_clkdiv(new_index);
			/* 2. Change the apll m,p,s value */
			set_apll(new_index, old_index);
		}
	} else if (old_index < new_index) {
		if (!exynos5250_pms_change(old_index, new_index)) {
			/* 1. Change just s value in apll m,p,s value */
			tmp = __raw_readl(EXYNOS5_APLL_CON0);
			tmp &= ~(0x7 << 0);
			tmp |= (exynos5_apll_pms_table[new_index] & 0x7);
			__raw_writel(tmp, EXYNOS5_APLL_CON0);
			/* 2. Change the system clock divider values */
			set_clkdiv(new_index);
		} else {
			/* Clock Configuration Procedure */
			/* 1. Change the apll m,p,s value */
			set_apll(new_index, old_index);
			/* 2. Change the system clock divider values */
			set_clkdiv(new_index);
		}
	}
}

static void __init set_volt_table(void)
{
	unsigned int i;

	exynos5250_freq_table[L0].frequency = CPUFREQ_ENTRY_INVALID;
	exynos5250_freq_table[L1].frequency = CPUFREQ_ENTRY_INVALID;
	exynos5250_freq_table[L2].frequency = CPUFREQ_ENTRY_INVALID;
	exynos5250_freq_table[L3].frequency = CPUFREQ_ENTRY_INVALID;
	exynos5250_freq_table[L4].frequency = CPUFREQ_ENTRY_INVALID;
	exynos5250_freq_table[L5].frequency = CPUFREQ_ENTRY_INVALID;
	exynos5250_freq_table[L6].frequency = CPUFREQ_ENTRY_INVALID;

	max_support_idx = L7;

	for (i = 0 ; i < CPUFREQ_LEVEL_END ; i++)
		exynos5250_volt_table[i] = asv_voltage_5250[i];
}

int exynos5250_cpufreq_init(struct exynos_dvfs_info *info)
{
	int i;
	unsigned int tmp;
	unsigned long rate;

	set_volt_table();

	cpu_clk = clk_get(NULL, "armclk");
	if (IS_ERR(cpu_clk))
		return PTR_ERR(cpu_clk);

	moutcore = clk_get(NULL, "mout_cpu");
	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;

	for (i = L0; i < CPUFREQ_LEVEL_END; i++) {

		exynos5250_clkdiv_table[i].index = i;

		tmp = __raw_readl(EXYNOS5_CLKDIV_CPU0);

		tmp &= ~((0x7 << 0) | (0x7 << 4) | (0x7 << 8) |
			(0x7 << 12) | (0x7 << 16) | (0x7 << 20) |
			(0x7 << 24) | (0x7 << 28));

		tmp |= ((clkdiv_cpu0_5250[i][0] << 0) |
			(clkdiv_cpu0_5250[i][1] << 4) |
			(clkdiv_cpu0_5250[i][2] << 8) |
			(clkdiv_cpu0_5250[i][3] << 12) |
			(clkdiv_cpu0_5250[i][4] << 16) |
			(clkdiv_cpu0_5250[i][5] << 20) |
			(clkdiv_cpu0_5250[i][6] << 24) |
			(clkdiv_cpu0_5250[i][7] << 28));

		exynos5250_clkdiv_table[i].clkdiv = tmp;

		tmp = __raw_readl(EXYNOS5_CLKDIV_CPU1);

		tmp &= ~((0x7 << 0) | (0x7 << 4));

		tmp |= ((clkdiv_cpu1_5250[i][0] << 0) |
			(clkdiv_cpu1_5250[i][1] << 4));

		exynos5250_clkdiv_table[i].clkdiv1 = tmp;
	}

	info->mpll_freq_khz = rate;
	/* 1000Mhz */
	info->pm_lock_idx = L7;
	/* 800Mhz */
	info->pll_safe_idx = L9;
	info->max_support_idx = max_support_idx;
	info->min_support_idx = min_support_idx;
	info->cpu_clk = cpu_clk;
	info->volt_table = exynos5250_volt_table;
	info->freq_table = exynos5250_freq_table;
	info->set_freq = exynos5250_set_frequency;
	info->need_apll_change = exynos5250_pms_change;

	return 0;

err_mout_apll:
	clk_put(mout_mpll);
err_mout_mpll:
	clk_put(moutcore);
err_moutcore:
	clk_put(cpu_clk);

	pr_err("%s: failed initialization\n", __func__);
	return -EINVAL;
}
EXPORT_SYMBOL(exynos5250_cpufreq_init);