/*
   * Copyright (c) 2010-2012 Samsung Electronics Co., Ltd.
   *		http://www.samsung.com
   *
   * EXYNOS4X12 - 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 exynos4x12_volt_table[] = {
  	1350000, 1287500, 1250000, 1187500, 1137500, 1087500, 1037500,
  	1000000,  987500,  975000,  950000,  925000,  900000,  900000

  };

  static struct cpufreq_frequency_table exynos4x12_freq_table[] = {

  	{CPUFREQ_BOOST_FREQ, L0, 1500 * 1000},
  	{0, L1, 1400 * 1000},
  	{0, L2, 1300 * 1000},
  	{0, L3, 1200 * 1000},
  	{0, L4, 1100 * 1000},
  	{0, L5, 1000 * 1000},
  	{0, L6,  900 * 1000},
  	{0, L7,  800 * 1000},
  	{0, L8,  700 * 1000},
  	{0, L9,  600 * 1000},
  	{0, L10, 500 * 1000},
  	{0, L11, 400 * 1000},
  	{0, L12, 300 * 1000},
  	{0, L13, 200 * 1000},
  	{0, 0, CPUFREQ_TABLE_END},

  };

  static struct apll_freq *apll_freq_4x12;

  static struct apll_freq apll_freq_4212[] = {

  	/*

  	 * values:
  	 * freq
  	 * clock divider for CORE, COREM0, COREM1, PERIPH, ATB, PCLK_DBG, APLL, CORE2
  	 * clock divider for COPY, HPM, RESERVED
  	 * PLL M, P, S

  	 */

  	APLL_FREQ(1500, 0, 3, 7, 0, 6, 1, 2, 0, 6, 2, 0, 250, 4, 0),
  	APLL_FREQ(1400, 0, 3, 7, 0, 6, 1, 2, 0, 6, 2, 0, 175, 3, 0),
  	APLL_FREQ(1300, 0, 3, 7, 0, 5, 1, 2, 0, 5, 2, 0, 325, 6, 0),
  	APLL_FREQ(1200, 0, 3, 7, 0, 5, 1, 2, 0, 5, 2, 0, 200, 4, 0),
  	APLL_FREQ(1100, 0, 3, 6, 0, 4, 1, 2, 0, 4, 2, 0, 275, 6, 0),
  	APLL_FREQ(1000, 0, 2, 5, 0, 4, 1, 1, 0, 4, 2, 0, 125, 3, 0),
  	APLL_FREQ(900,  0, 2, 5, 0, 3, 1, 1, 0, 3, 2, 0, 150, 4, 0),
  	APLL_FREQ(800,  0, 2, 5, 0, 3, 1, 1, 0, 3, 2, 0, 100, 3, 0),
  	APLL_FREQ(700,  0, 2, 4, 0, 3, 1, 1, 0, 3, 2, 0, 175, 3, 1),
  	APLL_FREQ(600,  0, 2, 4, 0, 3, 1, 1, 0, 3, 2, 0, 200, 4, 1),
  	APLL_FREQ(500,  0, 2, 4, 0, 3, 1, 1, 0, 3, 2, 0, 125, 3, 1),
  	APLL_FREQ(400,  0, 2, 4, 0, 3, 1, 1, 0, 3, 2, 0, 100, 3, 1),
  	APLL_FREQ(300,  0, 2, 4, 0, 2, 1, 1, 0, 3, 2, 0, 200, 4, 2),
  	APLL_FREQ(200,  0, 1, 3, 0, 1, 1, 1, 0, 3, 2, 0, 100, 3, 2),

  };

  static struct apll_freq apll_freq_4412[] = {

  	/*

  	 * values:
  	 * freq
  	 * clock divider for CORE, COREM0, COREM1, PERIPH, ATB, PCLK_DBG, APLL, CORE2
  	 * clock divider for COPY, HPM, CORES
  	 * PLL M, P, S

  	 */

  	APLL_FREQ(1500, 0, 3, 7, 0, 6, 1, 2, 0, 6, 0, 7, 250, 4, 0),
  	APLL_FREQ(1400, 0, 3, 7, 0, 6, 1, 2, 0, 6, 0, 6, 175, 3, 0),
  	APLL_FREQ(1300, 0, 3, 7, 0, 5, 1, 2, 0, 5, 0, 6, 325, 6, 0),
  	APLL_FREQ(1200, 0, 3, 7, 0, 5, 1, 2, 0, 5, 0, 5, 200, 4, 0),
  	APLL_FREQ(1100, 0, 3, 6, 0, 4, 1, 2, 0, 4, 0, 5, 275, 6, 0),
  	APLL_FREQ(1000, 0, 2, 5, 0, 4, 1, 1, 0, 4, 0, 4, 125, 3, 0),
  	APLL_FREQ(900,  0, 2, 5, 0, 3, 1, 1, 0, 3, 0, 4, 150, 4, 0),
  	APLL_FREQ(800,  0, 2, 5, 0, 3, 1, 1, 0, 3, 0, 3, 100, 3, 0),
  	APLL_FREQ(700,  0, 2, 4, 0, 3, 1, 1, 0, 3, 0, 3, 175, 3, 1),
  	APLL_FREQ(600,  0, 2, 4, 0, 3, 1, 1, 0, 3, 0, 2, 200, 4, 1),
  	APLL_FREQ(500,  0, 2, 4, 0, 3, 1, 1, 0, 3, 0, 2, 125, 3, 1),
  	APLL_FREQ(400,  0, 2, 4, 0, 3, 1, 1, 0, 3, 0, 1, 100, 3, 1),
  	APLL_FREQ(300,  0, 2, 4, 0, 2, 1, 1, 0, 3, 0, 1, 200, 4, 2),
  	APLL_FREQ(200,  0, 1, 3, 0, 1, 1, 1, 0, 3, 0, 0, 100, 3, 2),

  };
  
  static void exynos4x12_set_clkdiv(unsigned int div_index)
  {
  	unsigned int tmp;

  
  	/* Change Divider - CPU0 */

  	tmp = apll_freq_4x12[div_index].clk_div_cpu0;

  	__raw_writel(tmp, cpufreq->cmu_regs + EXYNOS4_CLKDIV_CPU);

  	while (__raw_readl(cpufreq->cmu_regs + EXYNOS4_CLKDIV_STATCPU)
  	       & 0x11111111)

  		cpu_relax();
  
  	/* Change Divider - CPU1 */

  	tmp = apll_freq_4x12[div_index].clk_div_cpu1;

  	__raw_writel(tmp, cpufreq->cmu_regs + EXYNOS4_CLKDIV_CPU1);

  	do {

  		cpu_relax();

  		tmp = __raw_readl(cpufreq->cmu_regs + EXYNOS4_CLKDIV_STATCPU1);

  	} while (tmp != 0x0);

  }
  
  static void exynos4x12_set_apll(unsigned int index)
  {

  	unsigned int tmp, freq = apll_freq_4x12[index].freq;

  	/* MUX_CORE_SEL = MPLL, ARMCLK uses MPLL for lock time */

  	clk_set_parent(moutcore, mout_mpll);
  
  	do {
  		cpu_relax();

  		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 {
  		cpu_relax();

  		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 exynos4x12_set_frequency(unsigned int old_index,
  				  unsigned int new_index)
  {

  	if (old_index > new_index) {

  		exynos4x12_set_clkdiv(new_index);
  		exynos4x12_set_apll(new_index);

  	} else if (old_index < new_index) {

  		exynos4x12_set_apll(new_index);
  		exynos4x12_set_clkdiv(new_index);

  	}
  }

  int exynos4x12_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-dt driver.

  	 */
  	np = of_find_compatible_node(NULL, NULL, "samsung,exynos4412-clock");
  	if (!np) {
  		pr_err("%s: failed to find clock controller DT node
  ",
  			__func__);
  		return -ENODEV;
  	}
  
  	info->cmu_regs = of_iomap(np, 0);
  	if (!info->cmu_regs) {
  		pr_err("%s: failed to map CMU registers
  ", __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;

  	if (info->type == EXYNOS_SOC_4212)

  		apll_freq_4x12 = apll_freq_4212;
  	else
  		apll_freq_4x12 = apll_freq_4412;

  
  	info->mpll_freq_khz = rate;

  	/* 800Mhz */

  	info->pll_safe_idx = L7;

  	info->cpu_clk = cpu_clk;
  	info->volt_table = exynos4x12_volt_table;
  	info->freq_table = exynos4x12_freq_table;
  	info->set_freq = exynos4x12_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
  ", __func__);
  	return -EINVAL;
  }