ARM: S5PV310: Add support CPUFREQ

This patch adds support CPUFREQ driver for S5PV310 and S5PC210. This can
support DVFS(Dynamic Voltage and Frequency Scaling). The voltage scaling
depends on existence of regulator.
Sigend-off-by: NSunyoung Kang <sy0816.kang@samsung.com>
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>

arch/arm/mach-s5pv310/cpufreq.c

+/* linux/arch/arm/mach-s5pv310/cpufreq.c
+ *
+ * Copyright (c) 2010 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com
+ *
+ * S5PV310 - 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 <mach/map.h>
+#include <mach/regs-clock.h>
+#include <mach/regs-mem.h>
+
+#include <plat/clock.h>
+
+static struct clk *cpu_clk;
+static struct clk *moutcore;
+static struct clk *mout_mpll;
+static struct clk *mout_apll;
+
+#ifdef CONFIG_REGULATOR
+static struct regulator *arm_regulator;
+static struct regulator *int_regulator;
+#endif
+
+static struct cpufreq_freqs freqs;
+static unsigned int armclk_use_apll;
+static unsigned int memtype;
+
+enum s5pv310_memory_type {
+	DDR2 = 4,
+	LPDDR2,
+	DDR3,
+};
+
+enum cpufreq_level_index {
+	L0, L1, L2, L3, L4, CPUFREQ_LEVEL_END,
+};
+
+static struct cpufreq_frequency_table s5pv310_freq_table[] = {
+	{L0, 1000*1000},
+	{L1, 800*1000},
+	{L2, 400*1000},
+	{L3, 200*1000},
+	{L4, 100*1000},
+	{0, CPUFREQ_TABLE_END},
+};
+
+static unsigned int clkdiv_cpu0[CPUFREQ_LEVEL_END + 1][7] = {
+	/*
+	 * Clock divider value for following
+	 * { DIVCORE, DIVCOREM0, DIVCOREM1, DIVPERIPH,
+	 *		DIVATB, DIVPCLK_DBG, DIVAPLL }
+	 */
+
+	/* ARM L0: 1000MHz */
+	{ 0, 3, 7, 3, 3, 0, 0 },
+
+	/* ARM L1: 800MHz */
+	{ 0, 3, 7, 3, 3, 0, 0 },
+
+	/* ARM L2: 400MHz */
+	{ 1, 1, 3, 1, 1, 0, 0 },
+
+	/* ARM L3: 200MHz */
+	{ 3, 0, 1, 0, 0, 0, 0 },
+
+	/* ARM L4A: 100MHz, for DDR2/3 */
+	{ 7, 0, 1, 0, 0, 0, 0 },
+
+	/* ARM L4B: 100MHz, for LPDDR2 (SMDKV310 has LPDDR2) */
+	{ 7, 0, 1, 0, 0, 0, 0 },
+};
+
+static unsigned int clkdiv_dmc0[CPUFREQ_LEVEL_END + 1][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: 400MHz */
+	{ 3, 1, 1, 1, 1, 1, 3, 1 },
+
+	/* DMC L3: 400MHz */
+	{ 3, 1, 1, 1, 1, 1, 3, 1 },
+
+	/* DMC L4A: 400MHz, for DDR2/3 */
+	{ 7, 1, 1, 1, 1, 1, 3, 1 },
+
+	/* DMC L4B: 200MHz, for LPDDR2 */
+	{ 7, 1, 1, 3, 1, 1, 3, 1 },
+};
+
+static unsigned int clkdiv_top[CPUFREQ_LEVEL_END + 1][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: 200MHz */
+	{ 3, 7, 4, 5, 1 },
+
+	/* ACLK200 L3: 200MHz */
+	{ 3, 7, 4, 5, 1 },
+
+	/* ACLK200 L4A: 100MHz */
+	{ 7, 7, 7, 7, 1 },
+
+	/* ACLK200 L4B: 100MHz */
+	{ 7, 7, 7, 7, 1 },
+};
+
+static unsigned int clkdiv_lr_bus[CPUFREQ_LEVEL_END + 1][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: 200MHz */
+	{ 3, 1 },
+
+	/* ACLK_GDL/R L3: 200MHz */
+	{ 3, 1 },
+
+	/* ACLK_GDL/R L4A: 100MHz */
+	{ 7, 1 },
+
+	/* ACLK_GDL/R L4B: 100MHz */
+	{ 7, 1 },
+};
+
+struct cpufreq_voltage_table {
+	unsigned int	index;		/* any */
+	unsigned int	arm_volt;	/* uV */
+	unsigned int	int_volt;
+};
+
+static struct cpufreq_voltage_table s5pv310_volt_table[] = {
+	{
+		.index		= L0,
+		.arm_volt	= 1200000,
+		.int_volt	= 1100000,
+	}, {
+		.index		= L1,
+		.arm_volt	= 1100000,
+		.int_volt	= 1100000,
+	}, {
+		.index		= L2,
+		.arm_volt	= 1050000,
+		.int_volt	= 1100000,
+	}, {
+		.index		= L3,
+		.arm_volt	= 1050000,
+		.int_volt	= 1100000,
+	}, {
+		.index		= L4,
+		.arm_volt	= 1000000,
+		.int_volt	= 1000000,
+	},
+};
+
+int s5pv310_verify_speed(struct cpufreq_policy *policy)
+{
+	return cpufreq_frequency_table_verify(policy, s5pv310_freq_table);
+}
+
+unsigned int s5pv310_getspeed(unsigned int cpu)
+{
+	return clk_get_rate(cpu_clk) / 1000;
+}
+
+void s5pv310_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 - 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 int s5pv310_target(struct cpufreq_policy *policy,
+			  unsigned int target_freq,
+			  unsigned int relation)
+{
+	unsigned int index, div_index, tmp;
+	unsigned int arm_volt, int_volt;
+	unsigned int need_apll = 0;
+
+	freqs.old = s5pv310_getspeed(policy->cpu);
+
+	if (cpufreq_frequency_table_target(policy, s5pv310_freq_table,
+					   target_freq, relation, &index))
+		return -EINVAL;
+
+	freqs.new = s5pv310_freq_table[index].frequency;
+	freqs.cpu = policy->cpu;
+
+	if (freqs.new == freqs.old)
+		return 0;
+
+	/*
+	 * If freqs.new is higher than 800MHz
+	 * cpufreq driver should turn on apll
+	 */
+	if (index < L1)
+		need_apll = 1;
+
+	/* If the memory type is LPDDR2, use L4-B instead of L4-A */
+	if ((index == L4) && (memtype == LPDDR2))
+		div_index = index + 1;
+	else
+		div_index = index;
+
+	/* get the voltage value */
+	arm_volt = s5pv310_volt_table[index].arm_volt;
+	int_volt = s5pv310_volt_table[index].int_volt;
+
+	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
+
+	/* control regulator */
+	if (freqs.new > freqs.old) {
+		/* Voltage up */
+#ifdef CONFIG_REGULATOR
+		regulator_set_voltage(arm_regulator, arm_volt, arm_volt);
+		regulator_set_voltage(int_regulator, int_volt, int_volt);
+#endif
+	}
+
+	/* Clock Configuration Procedure */
+
+	/* 1. Change the system clock divider values */
+	s5pv310_set_clkdiv(div_index);
+
+	/* 2. Change the divider values for special clocks in CMU_TOP */
+	/* currently nothing */
+
+	/* 3. Change the XPLL values or Select the parent XPLL */
+	if (need_apll) {
+		if (!armclk_use_apll) {
+			/*
+			 * If the parent clock of armclk isn't apll
+			 * here need to set apll (include m,p,s value)
+			 */
+
+			/* a. 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);
+
+			/* b. Set APLL Lock time */
+			__raw_writel(S5P_APLL_LOCKTIME, S5P_APLL_LOCK);
+
+			/* c. Change PLL PMS values */
+			__raw_writel(S5P_APLL_VAL_1000, S5P_APLL_CON0);
+
+			/* d. Turn on a PLL */
+			tmp = __raw_readl(S5P_APLL_CON0);
+			tmp |= (0x1 << S5P_APLLCON0_ENABLE_SHIFT);
+			__raw_writel(tmp, S5P_APLL_CON0);
+
+			/* e. wait_lock_time */
+			do {
+				tmp = __raw_readl(S5P_APLL_CON0);
+			} while (!(tmp & (0x1 << S5P_APLLCON0_LOCKED_SHIFT)));
+
+			armclk_use_apll = 1;
+
+		}
+
+		/* 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));
+
+	} else {
+		if (clk_get_parent(moutcore) != mout_mpll) {
+			clk_set_parent(moutcore, mout_mpll);
+
+			do {
+				tmp = __raw_readl(S5P_CLKMUX_STATCPU);
+				tmp &= S5P_CLKMUX_STATCPU_MUXCORE_MASK;
+			} while (tmp != (0x2 << S5P_CLKSRC_CPU_MUXCORE_SHIFT));
+		}
+	}
+
+	/* control regulator */
+	if (freqs.new < freqs.old) {
+		/* Voltage down */
+#ifdef CONFIG_REGULATOR
+		regulator_set_voltage(arm_regulator, arm_volt, arm_volt);
+		regulator_set_voltage(int_regulator, int_volt, int_volt);
+#endif
+	}
+
+	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int s5pv310_cpufreq_suspend(struct cpufreq_policy *policy,
+				   pm_message_t pmsg)
+{
+	return 0;
+}
+
+static int s5pv310_cpufreq_resume(struct cpufreq_policy *policy)
+{
+	return 0;
+}
+#endif
+
+static int s5pv310_cpufreq_cpu_init(struct cpufreq_policy *policy)
+{
+	policy->cur = policy->min = policy->max = s5pv310_getspeed(policy->cpu);
+
+	cpufreq_frequency_table_get_attr(s5pv310_freq_table, policy->cpu);
+
+	/* set the transition latency value */
+	policy->cpuinfo.transition_latency = 100000;
+
+	/*
+	 * S5PV310 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);
+
+	return cpufreq_frequency_table_cpuinfo(policy, s5pv310_freq_table);
+}
+
+static struct cpufreq_driver s5pv310_driver = {
+	.flags		= CPUFREQ_STICKY,
+	.verify		= s5pv310_verify_speed,
+	.target		= s5pv310_target,
+	.get		= s5pv310_getspeed,
+	.init		= s5pv310_cpufreq_cpu_init,
+	.name		= "s5pv310_cpufreq",
+#ifdef CONFIG_PM
+	.suspend	= s5pv310_cpufreq_suspend,
+	.resume		= s5pv310_cpufreq_resume,
+#endif
+};
+
+static int __init s5pv310_cpufreq_init(void)
+{
+	unsigned int tmp;
+
+	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 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;
+
+#ifdef CONFIG_REGULATOR
+	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;
+	}
+#endif
+
+	/* check parent clock of armclk */
+	tmp = __raw_readl(S5P_CLKSRC_CPU);
+	if (tmp & S5P_CLKSRC_CPU_MUXCORE_SHIFT)
+		armclk_use_apll = 0;
+	else
+		armclk_use_apll = 1;
+
+	/*
+	 * 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);
+	}
+
+	return cpufreq_register_driver(&s5pv310_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);
+
+#ifdef CONFIG_REGULATOR
+	if (!IS_ERR(arm_regulator))
+		regulator_put(arm_regulator);
+
+	if (!IS_ERR(int_regulator))
+		regulator_put(int_regulator);
+#endif
+
+	printk(KERN_ERR "%s: failed initialization\n", __func__);
+
+	return -EINVAL;
+}
+late_initcall(s5pv310_cpufreq_init);