arch/arm/mach-exynos/cpuidle.c

   1 /* linux/arch/arm/mach-exynos4/cpuidle.c
   2  *
   3  * Copyright (c) 2011 Samsung Electronics Co., Ltd.
   4  *              http://www.samsung.com
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9 */
  10
  11 #include <linux/kernel.h>
  12 #include <linux/init.h>
  13 #include <linux/cpuidle.h>
  14 #include <linux/cpu_pm.h>
  15 #include <linux/io.h>
  16 #include <linux/export.h>
  17 #include <linux/time.h>
  18 #include <linux/platform_device.h>
  19
  20 #include <asm/proc-fns.h>
  21 #include <asm/smp_scu.h>
  22 #include <asm/suspend.h>
  23 #include <asm/unified.h>
  24 #include <asm/cpuidle.h>
  25
  26 #include <plat/cpu.h>
  27 #include <plat/pm.h>
  28
  29 #include <mach/map.h>
  30
  31 #include "common.h"
  32 #include "regs-pmu.h"
  33
  34 #define REG_DIRECTGO_ADDR       (samsung_rev() == EXYNOS4210_REV_1_1 ? \
  35                         S5P_INFORM7 : (samsung_rev() == EXYNOS4210_REV_1_0 ? \
  36                         (S5P_VA_SYSRAM + 0x24) : S5P_INFORM0))
  37 #define REG_DIRECTGO_FLAG       (samsung_rev() == EXYNOS4210_REV_1_1 ? \
  38                         S5P_INFORM6 : (samsung_rev() == EXYNOS4210_REV_1_0 ? \
  39                         (S5P_VA_SYSRAM + 0x20) : S5P_INFORM1))
  40
  41 #define S5P_CHECK_AFTR          0xFCBA0D10
  42
  43 #define EXYNOS5_PWR_CTRL1                       (S5P_VA_CMU + 0x01020)
  44 #define EXYNOS5_PWR_CTRL2                       (S5P_VA_CMU + 0x01024)
  45
  46 #define PWR_CTRL1_CORE2_DOWN_RATIO              (7 << 28)
  47 #define PWR_CTRL1_CORE1_DOWN_RATIO              (7 << 16)
  48 #define PWR_CTRL1_DIV2_DOWN_EN                  (1 << 9)
  49 #define PWR_CTRL1_DIV1_DOWN_EN                  (1 << 8)
  50 #define PWR_CTRL1_USE_CORE1_WFE                 (1 << 5)
  51 #define PWR_CTRL1_USE_CORE0_WFE                 (1 << 4)
  52 #define PWR_CTRL1_USE_CORE1_WFI                 (1 << 1)
  53 #define PWR_CTRL1_USE_CORE0_WFI                 (1 << 0)
  54
  55 #define PWR_CTRL2_DIV2_UP_EN                    (1 << 25)
  56 #define PWR_CTRL2_DIV1_UP_EN                    (1 << 24)
  57 #define PWR_CTRL2_DUR_STANDBY2_VAL              (1 << 16)
  58 #define PWR_CTRL2_DUR_STANDBY1_VAL              (1 << 8)
  59 #define PWR_CTRL2_CORE2_UP_RATIO                (1 << 4)
  60 #define PWR_CTRL2_CORE1_UP_RATIO                (1 << 0)
  61
  62 static int exynos4_enter_lowpower(struct cpuidle_device *dev,
  63                                 struct cpuidle_driver *drv,
  64                                 int index);
  65
  66 static DEFINE_PER_CPU(struct cpuidle_device, exynos4_cpuidle_device);
  67
  68 static struct cpuidle_driver exynos4_idle_driver = {
  69         .name                   = "exynos4_idle",
  70         .owner                  = THIS_MODULE,
  71         .states = {
  72                 [0] = ARM_CPUIDLE_WFI_STATE,
  73                 [1] = {
  74                         .enter                  = exynos4_enter_lowpower,
  75                         .exit_latency           = 300,
  76                         .target_residency       = 100000,
  77                         .flags                  = CPUIDLE_FLAG_TIME_VALID,
  78                         .name                   = "C1",
  79                         .desc                   = "ARM power down",
  80                 },
  81         },
  82         .state_count = 2,
  83         .safe_state_index = 0,
  84 };
  85
  86 /* Ext-GIC nIRQ/nFIQ is the only wakeup source in AFTR */
  87 static void exynos4_set_wakeupmask(void)
  88 {
  89         __raw_writel(0x0000ff3e, S5P_WAKEUP_MASK);
  90 }
  91
  92 static unsigned int g_pwr_ctrl, g_diag_reg;
  93
  94 static void save_cpu_arch_register(void)
  95 {
  96         /*read power control register*/
  97         asm("mrc p15, 0, %0, c15, c0, 0" : "=r"(g_pwr_ctrl) : : "cc");
  98         /*read diagnostic register*/
  99         asm("mrc p15, 0, %0, c15, c0, 1" : "=r"(g_diag_reg) : : "cc");
 100         return;
 101 }
 102
 103 static void restore_cpu_arch_register(void)
 104 {
 105         /*write power control register*/
 106         asm("mcr p15, 0, %0, c15, c0, 0" : : "r"(g_pwr_ctrl) : "cc");
 107         /*write diagnostic register*/
 108         asm("mcr p15, 0, %0, c15, c0, 1" : : "r"(g_diag_reg) : "cc");
 109         return;
 110 }
 111
 112 static int idle_finisher(unsigned long flags)
 113 {
 114         cpu_do_idle();
 115         return 1;
 116 }
 117
 118 static int exynos4_enter_core0_aftr(struct cpuidle_device *dev,
 119                                 struct cpuidle_driver *drv,
 120                                 int index)
 121 {
 122         unsigned long tmp;
 123
 124         exynos4_set_wakeupmask();
 125
 126         /* Set value of power down register for aftr mode */
 127         exynos_sys_powerdown_conf(SYS_AFTR);
 128
 129         __raw_writel(virt_to_phys(exynos_cpu_resume), REG_DIRECTGO_ADDR);
 130         __raw_writel(S5P_CHECK_AFTR, REG_DIRECTGO_FLAG);
 131
 132         save_cpu_arch_register();
 133
 134         /* Setting Central Sequence Register for power down mode */
 135         tmp = __raw_readl(S5P_CENTRAL_SEQ_CONFIGURATION);
 136         tmp &= ~S5P_CENTRAL_LOWPWR_CFG;
 137         __raw_writel(tmp, S5P_CENTRAL_SEQ_CONFIGURATION);
 138
 139         cpu_pm_enter();
 140         cpu_suspend(0, idle_finisher);
 141
 142 #ifdef CONFIG_SMP
 143         if (!soc_is_exynos5250())
 144                 scu_enable(S5P_VA_SCU);
 145 #endif
 146         cpu_pm_exit();
 147
 148         restore_cpu_arch_register();
 149
 150         /*
 151          * If PMU failed while entering sleep mode, WFI will be
 152          * ignored by PMU and then exiting cpu_do_idle().
 153          * S5P_CENTRAL_LOWPWR_CFG bit will not be set automatically
 154          * in this situation.
 155          */
 156         tmp = __raw_readl(S5P_CENTRAL_SEQ_CONFIGURATION);
 157         if (!(tmp & S5P_CENTRAL_LOWPWR_CFG)) {
 158                 tmp |= S5P_CENTRAL_LOWPWR_CFG;
 159                 __raw_writel(tmp, S5P_CENTRAL_SEQ_CONFIGURATION);
 160         }
 161
 162         /* Clear wakeup state register */
 163         __raw_writel(0x0, S5P_WAKEUP_STAT);
 164
 165         return index;
 166 }
 167
 168 static int exynos4_enter_lowpower(struct cpuidle_device *dev,
 169                                 struct cpuidle_driver *drv,
 170                                 int index)
 171 {
 172         int new_index = index;
 173
 174         /* AFTR can only be entered when cores other than CPU0 are offline */
 175         if (num_online_cpus() > 1 || dev->cpu != 0)
 176                 new_index = drv->safe_state_index;
 177
 178         if (new_index == 0)
 179                 return arm_cpuidle_simple_enter(dev, drv, new_index);
 180         else
 181                 return exynos4_enter_core0_aftr(dev, drv, new_index);
 182 }
 183
 184 static void __init exynos5_core_down_clk(void)
 185 {
 186         unsigned int tmp;
 187
 188         /*
 189          * Enable arm clock down (in idle) and set arm divider
 190          * ratios in WFI/WFE state.
 191          */
 192         tmp = PWR_CTRL1_CORE2_DOWN_RATIO | \
 193               PWR_CTRL1_CORE1_DOWN_RATIO | \
 194               PWR_CTRL1_DIV2_DOWN_EN     | \
 195               PWR_CTRL1_DIV1_DOWN_EN     | \
 196               PWR_CTRL1_USE_CORE1_WFE    | \
 197               PWR_CTRL1_USE_CORE0_WFE    | \
 198               PWR_CTRL1_USE_CORE1_WFI    | \
 199               PWR_CTRL1_USE_CORE0_WFI;
 200         __raw_writel(tmp, EXYNOS5_PWR_CTRL1);
 201
 202         /*
 203          * Enable arm clock up (on exiting idle). Set arm divider
 204          * ratios when not in idle along with the standby duration
 205          * ratios.
 206          */
 207         tmp = PWR_CTRL2_DIV2_UP_EN       | \
 208               PWR_CTRL2_DIV1_UP_EN       | \
 209               PWR_CTRL2_DUR_STANDBY2_VAL | \
 210               PWR_CTRL2_DUR_STANDBY1_VAL | \
 211               PWR_CTRL2_CORE2_UP_RATIO   | \
 212               PWR_CTRL2_CORE1_UP_RATIO;
 213         __raw_writel(tmp, EXYNOS5_PWR_CTRL2);
 214 }
 215
 216 static int exynos_cpuidle_probe(struct platform_device *pdev)
 217 {
 218         int cpu_id, ret;
 219         struct cpuidle_device *device;
 220
 221         if (soc_is_exynos5250())
 222                 exynos5_core_down_clk();
 223
 224         if (soc_is_exynos5440())
 225                 exynos4_idle_driver.state_count = 1;
 226
 227         ret = cpuidle_register_driver(&exynos4_idle_driver);
 228         if (ret) {
 229                 dev_err(&pdev->dev, "failed to register cpuidle driver\n");
 230                 return ret;
 231         }
 232
 233         for_each_online_cpu(cpu_id) {
 234                 device = &per_cpu(exynos4_cpuidle_device, cpu_id);
 235                 device->cpu = cpu_id;
 236
 237                 ret = cpuidle_register_device(device);
 238                 if (ret) {
 239                         dev_err(&pdev->dev, "failed to register cpuidle device\n");
 240                         return ret;
 241                 }
 242         }
 243
 244         return 0;
 245 }
 246
 247 static struct platform_driver exynos_cpuidle_driver = {
 248         .probe  = exynos_cpuidle_probe,
 249         .driver = {
 250                 .name = "exynos_cpuidle",
 251                 .owner = THIS_MODULE,
 252         },
 253 };
 254
 255 module_platform_driver(exynos_cpuidle_driver);