[PATCH v2 5/6] ARM: S5PV210: Add support CPUFREQ
Sangbeom Kim
sbkim73 at samsung.com
Mon Sep 20 02:04:54 EDT 2010
From: Jaecheol Lee <jc.lee at samsung.com>
This patch adds CPUFREQ driver for supporting DFS(Dynamic Frequency Scaling).
Signed-off-by: Jaecheol Lee <jc.lee at samsung.com>
Signed-off-by: Sangbeom Kim <sbkim73 at samsung.com>
---
Changes since v1:
- Removed hardcoding of DRAM refresh counter
- Added to calculate refresh counter function based on DRAM operation freq.
arch/arm/mach-s5pv210/cpufreq.c | 484 +++++++++++++++++++++++++++++++++++++++
1 files changed, 484 insertions(+), 0 deletions(-)
create mode 100644 arch/arm/mach-s5pv210/cpufreq.c
diff --git a/arch/arm/mach-s5pv210/cpufreq.c b/arch/arm/mach-s5pv210/cpufreq.c
new file mode 100644
index 0000000..465ffe6
--- /dev/null
+++ b/arch/arm/mach-s5pv210/cpufreq.c
@@ -0,0 +1,484 @@
+/* linux/arch/arm/mach-s5pv210/cpufreq.c
+ *
+ * Copyright (c) 2010 Samsung Electronics Co., Ltd.
+ * http://www.samsung.com
+ *
+ * CPU frequency scaling for S5PC110/S5PV210
+ *
+ * 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/init.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/cpufreq.h>
+
+#include <mach/map.h>
+#include <mach/regs-clock.h>
+
+static struct clk *cpu_clk;
+static struct clk *dmc0_clk;
+static struct clk *dmc1_clk;
+static struct cpufreq_freqs freqs;
+
+/* APLL M,P,S values for 1G/800Mhz */
+#define APLL_VAL_1000 ((1 << 31) | (125 << 16) | (3 << 8) | 1)
+#define APLL_VAL_800 ((1 << 31) | (100 << 16) | (3 << 8) | 1)
+
+/*
+ * DRAM configurations to calculate refresh counter for changing
+ * frequency of memory.
+ */
+struct dram_conf {
+ unsigned long freq; /* HZ */
+ unsigned long refresh; /* DRAM refresh counter * 1000 */
+};
+
+/* DRAM configuration (DMC0 and DMC1) */
+static struct dram_conf s5pv210_dram_conf[2];
+
+enum perf_level {
+ L0, L1, L2, L3, L4,
+};
+
+enum s5pv210_mem_type {
+ LPDDR = 0x1,
+ LPDDR2 = 0x2,
+ DDR2 = 0x4,
+};
+
+enum s5pv210_dmc_port {
+ DMC0 = 0,
+ DMC1,
+};
+
+static struct cpufreq_frequency_table s5pv210_freq_table[] = {
+ {L0, 1000*1000},
+ {L1, 800*1000},
+ {L2, 400*1000},
+ {L3, 200*1000},
+ {L4, 100*1000},
+ {0, CPUFREQ_TABLE_END},
+};
+
+static u32 clkdiv_val[5][11] = {
+ /*
+ * Clock divider value for following
+ * { APLL, A2M, HCLK_MSYS, PCLK_MSYS,
+ * HCLK_DSYS, PCLK_DSYS, HCLK_PSYS, PCLK_PSYS,
+ * ONEDRAM, MFC, G3D }
+ */
+
+ /* L0 : [1000/200/100][166/83][133/66][200/200] */
+ {0, 4, 4, 1, 3, 1, 4, 1, 3, 0, 0},
+
+ /* L1 : [800/200/100][166/83][133/66][200/200] */
+ {0, 3, 3, 1, 3, 1, 4, 1, 3, 0, 0},
+
+ /* L2 : [400/200/100][166/83][133/66][200/200] */
+ {1, 3, 1, 1, 3, 1, 4, 1, 3, 0, 0},
+
+ /* L3 : [200/200/100][166/83][133/66][200/200] */
+ {3, 3, 1, 1, 3, 1, 4, 1, 3, 0, 0},
+
+ /* L4 : [100/100/100][83/83][66/66][100/100] */
+ {7, 7, 0, 0, 7, 0, 9, 0, 7, 0, 0},
+};
+
+/*
+ * This function set DRAM refresh counter
+ * accoriding to operating frequency of DRAM
+ * ch: DMC port number 0 or 1
+ * freq: Operating frequency of DRAM(KHz)
+ */
+static void s5pv210_set_refresh(enum s5pv210_dmc_port ch, unsigned long freq)
+{
+ unsigned long tmp, tmp1;
+ void __iomem *reg = NULL;
+
+ if (ch == DMC0)
+ reg = (S5P_VA_DMC0 + 0x30);
+ else if (ch == DMC1)
+ reg = (S5P_VA_DMC1 + 0x30);
+ else
+ printk(KERN_ERR "Cannot find DMC port\n");
+
+ /* Find current DRAM frequency */
+ tmp = s5pv210_dram_conf[ch].freq;
+
+ do_div(tmp, freq);
+
+ tmp1 = s5pv210_dram_conf[ch].refresh;
+
+ do_div(tmp1, tmp);
+
+ __raw_writel(tmp1, reg);
+}
+
+int s5pv210_verify_speed(struct cpufreq_policy *policy)
+{
+ if (policy->cpu)
+ return -EINVAL;
+
+ return cpufreq_frequency_table_verify(policy, s5pv210_freq_table);
+}
+
+unsigned int s5pv210_getspeed(unsigned int cpu)
+{
+ if (cpu)
+ return 0;
+
+ return clk_get_rate(cpu_clk) / 1000;
+}
+
+static int s5pv210_target(struct cpufreq_policy *policy,
+ unsigned int target_freq,
+ unsigned int relation)
+{
+ unsigned long reg;
+ unsigned int index, priv_index;
+ unsigned int pll_changing = 0;
+ unsigned int bus_speed_changing = 0;
+
+ freqs.old = s5pv210_getspeed(0);
+
+ if (cpufreq_frequency_table_target(policy, s5pv210_freq_table,
+ target_freq, relation, &index))
+ return -EINVAL;
+
+ freqs.new = s5pv210_freq_table[index].frequency;
+ freqs.cpu = 0;
+
+ if (freqs.new == freqs.old)
+ return 0;
+
+ /* Finding current running level index */
+ if (cpufreq_frequency_table_target(policy, s5pv210_freq_table,
+ freqs.old, relation, &priv_index))
+ return -EINVAL;
+
+ cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
+
+ if (freqs.new > freqs.old) {
+ /* Voltage up: will be implemented */
+ }
+
+ /* Check if there need to change PLL */
+ if ((index == L0) || (priv_index == L0))
+ pll_changing = 1;
+
+ /* Check if there need to change System bus clock */
+ if ((index == L4) || (priv_index == L4))
+ bus_speed_changing = 1;
+
+ if (bus_speed_changing) {
+ /*
+ * Reconfigure DRAM refresh counter value for minimum
+ * temporary clock while changing divider.
+ * expected clock is 83Mhz : 7.8usec/(1/83Mhz) = 0x287
+ */
+ if (pll_changing)
+ s5pv210_set_refresh(DMC1, 83000);
+ else
+ s5pv210_set_refresh(DMC1, 100000);
+
+ s5pv210_set_refresh(DMC0, 83000);
+ }
+
+ /*
+ * APLL should be changed in this level
+ * APLL -> MPLL(for stable transition) -> APLL
+ * Some clock source's clock API are not prepared.
+ * Do not use clock API in below code.
+ */
+ if (pll_changing) {
+ /*
+ * 1. Temporary Change divider for MFC and G3D
+ * SCLKA2M(200/1=200)->(200/4=50)Mhz
+ */
+ reg = __raw_readl(S5P_CLK_DIV2);
+ reg &= ~(S5P_CLKDIV2_G3D_MASK | S5P_CLKDIV2_MFC_MASK);
+ reg |= (3 << S5P_CLKDIV2_G3D_SHIFT) |
+ (3 << S5P_CLKDIV2_MFC_SHIFT);
+ __raw_writel(reg, S5P_CLK_DIV2);
+
+ /* For MFC, G3D dividing */
+ do {
+ reg = __raw_readl(S5P_CLKDIV_STAT0);
+ } while (reg & ((1 << 16) | (1 << 17)));
+
+ /*
+ * 2. Change SCLKA2M(200Mhz)to SCLKMPLL in MFC_MUX, G3D MUX
+ * (200/4=50)->(667/4=166)Mhz
+ */
+ reg = __raw_readl(S5P_CLK_SRC2);
+ reg &= ~(S5P_CLKSRC2_G3D_MASK | S5P_CLKSRC2_MFC_MASK);
+ reg |= (1 << S5P_CLKSRC2_G3D_SHIFT) |
+ (1 << S5P_CLKSRC2_MFC_SHIFT);
+ __raw_writel(reg, S5P_CLK_SRC2);
+
+ do {
+ reg = __raw_readl(S5P_CLKMUX_STAT1);
+ } while (reg & ((1 << 7) | (1 << 3)));
+
+ /*
+ * 3. DMC1 refresh count for 133Mhz if (index == L4) is
+ * true refresh counter is already programed in upper
+ * code. 0x287 at 83Mhz
+ */
+ if (!bus_speed_changing)
+ s5pv210_set_refresh(DMC1, 133000);
+
+ /* 4. SCLKAPLL -> SCLKMPLL */
+ reg = __raw_readl(S5P_CLK_SRC0);
+ reg &= ~(S5P_CLKSRC0_MUX200_MASK);
+ reg |= (0x1 << S5P_CLKSRC0_MUX200_SHIFT);
+ __raw_writel(reg, S5P_CLK_SRC0);
+
+ do {
+ reg = __raw_readl(S5P_CLKMUX_STAT0);
+ } while (reg & (0x1 << 18));
+
+ }
+
+ /* Change divider */
+ reg = __raw_readl(S5P_CLK_DIV0);
+
+ reg &= ~(S5P_CLKDIV0_APLL_MASK | S5P_CLKDIV0_A2M_MASK |
+ S5P_CLKDIV0_HCLK200_MASK | S5P_CLKDIV0_PCLK100_MASK |
+ S5P_CLKDIV0_HCLK166_MASK | S5P_CLKDIV0_PCLK83_MASK |
+ S5P_CLKDIV0_HCLK133_MASK | S5P_CLKDIV0_PCLK66_MASK);
+
+ reg |= ((clkdiv_val[index][0] << S5P_CLKDIV0_APLL_SHIFT) |
+ (clkdiv_val[index][1] << S5P_CLKDIV0_A2M_SHIFT) |
+ (clkdiv_val[index][2] << S5P_CLKDIV0_HCLK200_SHIFT) |
+ (clkdiv_val[index][3] << S5P_CLKDIV0_PCLK100_SHIFT) |
+ (clkdiv_val[index][4] << S5P_CLKDIV0_HCLK166_SHIFT) |
+ (clkdiv_val[index][5] << S5P_CLKDIV0_PCLK83_SHIFT) |
+ (clkdiv_val[index][6] << S5P_CLKDIV0_HCLK133_SHIFT) |
+ (clkdiv_val[index][7] << S5P_CLKDIV0_PCLK66_SHIFT));
+
+ __raw_writel(reg, S5P_CLK_DIV0);
+
+ do {
+ reg = __raw_readl(S5P_CLKDIV_STAT0);
+ } while (reg & 0xff);
+
+ /* ARM MCS value changed */
+ reg = __raw_readl(S5P_ARM_MCS_CON);
+ reg &= ~0x3;
+ if (index >= L3)
+ reg |= 0x3;
+ else
+ reg |= 0x1;
+
+ __raw_writel(reg, S5P_ARM_MCS_CON);
+
+ if (pll_changing) {
+ /* 5. Set Lock time = 30us*24Mhz = 0x2cf */
+ __raw_writel(0x2cf, S5P_APLL_LOCK);
+
+ /*
+ * 6. Turn on APLL
+ * 6-1. Set PMS values
+ * 6-2. Wait untile the PLL is locked
+ */
+ if (index == L0)
+ __raw_writel(APLL_VAL_1000, S5P_APLL_CON);
+ else
+ __raw_writel(APLL_VAL_800, S5P_APLL_CON);
+
+ do {
+ reg = __raw_readl(S5P_APLL_CON);
+ } while (!(reg & (0x1 << 29)));
+
+ /*
+ * 7. Change souce clock from SCLKMPLL(667Mhz)
+ * to SCLKA2M(200Mhz) in MFC_MUX and G3D MUX
+ * (667/4=166)->(200/4=50)Mhz
+ */
+ reg = __raw_readl(S5P_CLK_SRC2);
+ reg &= ~(S5P_CLKSRC2_G3D_MASK | S5P_CLKSRC2_MFC_MASK);
+ reg |= (0 << S5P_CLKSRC2_G3D_SHIFT) |
+ (0 << S5P_CLKSRC2_MFC_SHIFT);
+ __raw_writel(reg, S5P_CLK_SRC2);
+
+ do {
+ reg = __raw_readl(S5P_CLKMUX_STAT1);
+ } while (reg & ((1 << 7) | (1 << 3)));
+
+ /*
+ * 8. Change divider for MFC and G3D
+ * (200/4=50)->(200/1=200)Mhz
+ */
+ reg = __raw_readl(S5P_CLK_DIV2);
+ reg &= ~(S5P_CLKDIV2_G3D_MASK | S5P_CLKDIV2_MFC_MASK);
+ reg |= (clkdiv_val[index][10] << S5P_CLKDIV2_G3D_SHIFT) |
+ (clkdiv_val[index][9] << S5P_CLKDIV2_MFC_SHIFT);
+ __raw_writel(reg, S5P_CLK_DIV2);
+
+ /* For MFC, G3D dividing */
+ do {
+ reg = __raw_readl(S5P_CLKDIV_STAT0);
+ } while (reg & ((1 << 16) | (1 << 17)));
+
+ /* 9. Change MPLL to APLL in MSYS_MUX */
+ reg = __raw_readl(S5P_CLK_SRC0);
+ reg &= ~(S5P_CLKSRC0_MUX200_MASK);
+ reg |= (0x0 << S5P_CLKSRC0_MUX200_SHIFT);
+ __raw_writel(reg, S5P_CLK_SRC0);
+
+ do {
+ reg = __raw_readl(S5P_CLKMUX_STAT0);
+ } while (reg & (0x1 << 18));
+
+ /*
+ * 10. DMC1 refresh counter
+ * L4 : DMC1 = 100Mhz 7.8us/(1/100) = 0x30c
+ * Others : DMC1 = 200Mhz 7.8us/(1/200) = 0x618
+ */
+ if (!bus_speed_changing)
+ s5pv210_set_refresh(DMC1, 200000);
+ }
+
+ /*
+ * L4 level need to change memory bus speed, hence onedram clock divier
+ * and memory refresh parameter should be changed
+ */
+ if (bus_speed_changing) {
+ reg = __raw_readl(S5P_CLK_DIV6);
+ reg &= ~S5P_CLKDIV6_ONEDRAM_MASK;
+ reg |= (clkdiv_val[index][8] << S5P_CLKDIV6_ONEDRAM_SHIFT);
+ __raw_writel(reg, S5P_CLK_DIV6);
+
+ do {
+ reg = __raw_readl(S5P_CLKDIV_STAT1);
+ } while (reg & (1 << 15));
+
+ /* Reconfigure DRAM refresh counter value */
+ if (index != L4) {
+ /*
+ * DMC0 : 166Mhz
+ * DMC1 : 200Mhz
+ */
+ s5pv210_set_refresh(DMC0, 166000);
+ s5pv210_set_refresh(DMC1, 200000);
+ } else {
+ /*
+ * DMC0 : 83Mhz
+ * DMC1 : 100Mhz
+ */
+ s5pv210_set_refresh(DMC0, 83000);
+ s5pv210_set_refresh(DMC1, 100000);
+ }
+ }
+
+ if (freqs.new < freqs.old) {
+ /* Voltage down: will be implemented */
+ }
+
+ cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
+
+ printk(KERN_DEBUG "Perf changed[L%d]\n", index);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM
+static int s5pv210_cpufreq_suspend(struct cpufreq_policy *policy,
+ pm_message_t pmsg)
+{
+ return 0;
+}
+
+static int s5pv210_cpufreq_resume(struct cpufreq_policy *policy)
+{
+ return 0;
+}
+#endif
+
+static int check_mem_type(void __iomem *dmc_reg)
+{
+ unsigned long val;
+
+ val = __raw_readl(dmc_reg + 0x4);
+ val = (val & (0xf << 8));
+
+ return val >> 8;
+}
+
+static int __init s5pv210_cpu_init(struct cpufreq_policy *policy)
+{
+ unsigned long mem_type;
+
+ cpu_clk = clk_get(NULL, "armclk");
+ if (IS_ERR(cpu_clk))
+ return PTR_ERR(cpu_clk);
+
+ dmc0_clk = clk_get(NULL, "sclk_dmc0");
+ if (IS_ERR(dmc0_clk)) {
+ clk_put(cpu_clk);
+ return PTR_ERR(dmc0_clk);
+ }
+
+ dmc1_clk = clk_get(NULL, "hclk_msys");
+ if (IS_ERR(dmc1_clk)) {
+ clk_put(dmc0_clk);
+ clk_put(cpu_clk);
+ return PTR_ERR(dmc1_clk);
+ }
+
+ if (policy->cpu != 0)
+ return -EINVAL;
+
+ /*
+ * check_mem_type : This driver only support LPDDR & LPDDR2.
+ * other memory type is not supported.
+ */
+ mem_type = check_mem_type(S5P_VA_DMC0);
+
+ if ((mem_type != LPDDR) && (mem_type != LPDDR2)) {
+ printk(KERN_ERR "CPUFreq doesn't support this memory type\n");
+ return -EINVAL;
+ }
+
+ /* Find current refresh counter and frequency each DMC */
+ s5pv210_dram_conf[0].refresh = (__raw_readl(S5P_VA_DMC0 + 0x30) * 1000);
+ s5pv210_dram_conf[0].freq = clk_get_rate(dmc0_clk);
+
+ s5pv210_dram_conf[1].refresh = (__raw_readl(S5P_VA_DMC1 + 0x30) * 1000);
+ s5pv210_dram_conf[1].freq = clk_get_rate(dmc1_clk);
+
+ policy->cur = policy->min = policy->max = s5pv210_getspeed(0);
+
+ cpufreq_frequency_table_get_attr(s5pv210_freq_table, policy->cpu);
+
+ policy->cpuinfo.transition_latency = 40000;
+
+ return cpufreq_frequency_table_cpuinfo(policy, s5pv210_freq_table);
+}
+
+static struct cpufreq_driver s5pv210_driver = {
+ .flags = CPUFREQ_STICKY,
+ .verify = s5pv210_verify_speed,
+ .target = s5pv210_target,
+ .get = s5pv210_getspeed,
+ .init = s5pv210_cpu_init,
+ .name = "s5pv210",
+#ifdef CONFIG_PM
+ .suspend = s5pv210_cpufreq_suspend,
+ .resume = s5pv210_cpufreq_resume,
+#endif
+};
+
+static int __init s5pv210_cpufreq_init(void)
+{
+ return cpufreq_register_driver(&s5pv210_driver);
+}
+
+late_initcall(s5pv210_cpufreq_init);
--
1.6.2.5
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