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 #include <mach/regs-clock.h>
  26 #include <mach/regs-pmu.h>
  27
  28 #include <plat/cpu.h>
  29 #include <plat/pm.h>
  30
  31 #include "common.h"
  32
  33 #define REG_DIRECTGO_ADDR       (samsung_rev() == EXYNOS4210_REV_1_1 ? \
  34                         S5P_INFORM7 : (samsung_rev() == EXYNOS4210_REV_1_0 ? \
  35                         (S5P_VA_SYSRAM + 0x24) : S5P_INFORM0))
  36 #define REG_DIRECTGO_FLAG       (samsung_rev() == EXYNOS4210_REV_1_1 ? \
  37                         S5P_INFORM6 : (samsung_rev() == EXYNOS4210_REV_1_0 ? \
  38                         (S5P_VA_SYSRAM + 0x20) : S5P_INFORM1))
  39
  40 #define S5P_CHECK_AFTR          0xFCBA0D10
  41
  42 static int exynos4_enter_lowpower(struct cpuidle_device *dev,
  43                                 struct cpuidle_driver *drv,
  44                                 int index);
  45
  46 static DEFINE_PER_CPU(struct cpuidle_device, exynos4_cpuidle_device);
  47
  48 static struct cpuidle_driver exynos4_idle_driver = {
  49         .name                   = "exynos4_idle",
  50         .owner                  = THIS_MODULE,
  51         .states = {
  52                 [0] = ARM_CPUIDLE_WFI_STATE,
  53                 [1] = {
  54                         .enter                  = exynos4_enter_lowpower,
  55                         .exit_latency           = 300,
  56                         .target_residency       = 100000,
  57                         .flags                  = CPUIDLE_FLAG_TIME_VALID,
  58                         .name                   = "C1",
  59                         .desc                   = "ARM power down",
  60                 },
  61         },
  62         .state_count = 2,
  63         .safe_state_index = 0,
  64 };
  65
  66 /* Ext-GIC nIRQ/nFIQ is the only wakeup source in AFTR */
  67 static void exynos4_set_wakeupmask(void)
  68 {
  69         __raw_writel(0x0000ff3e, S5P_WAKEUP_MASK);
  70 }
  71
  72 static unsigned int g_pwr_ctrl, g_diag_reg;
  73
  74 static void save_cpu_arch_register(void)
  75 {
  76         /*read power control register*/
  77         asm("mrc p15, 0, %0, c15, c0, 0" : "=r"(g_pwr_ctrl) : : "cc");
  78         /*read diagnostic register*/
  79         asm("mrc p15, 0, %0, c15, c0, 1" : "=r"(g_diag_reg) : : "cc");
  80         return;
  81 }
  82
  83 static void restore_cpu_arch_register(void)
  84 {
  85         /*write power control register*/
  86         asm("mcr p15, 0, %0, c15, c0, 0" : : "r"(g_pwr_ctrl) : "cc");
  87         /*write diagnostic register*/
  88         asm("mcr p15, 0, %0, c15, c0, 1" : : "r"(g_diag_reg) : "cc");
  89         return;
  90 }
  91
  92 static int idle_finisher(unsigned long flags)
  93 {
  94         cpu_do_idle();
  95         return 1;
  96 }
  97
  98 static int exynos4_enter_core0_aftr(struct cpuidle_device *dev,
  99                                 struct cpuidle_driver *drv,
 100                                 int index)
 101 {
 102         unsigned long tmp;
 103
 104         exynos4_set_wakeupmask();
 105
 106         /* Set value of power down register for aftr mode */
 107         exynos_sys_powerdown_conf(SYS_AFTR);
 108
 109         __raw_writel(virt_to_phys(s3c_cpu_resume), REG_DIRECTGO_ADDR);
 110         __raw_writel(S5P_CHECK_AFTR, REG_DIRECTGO_FLAG);
 111
 112         save_cpu_arch_register();
 113
 114         /* Setting Central Sequence Register for power down mode */
 115         tmp = __raw_readl(S5P_CENTRAL_SEQ_CONFIGURATION);
 116         tmp &= ~S5P_CENTRAL_LOWPWR_CFG;
 117         __raw_writel(tmp, S5P_CENTRAL_SEQ_CONFIGURATION);
 118
 119         cpu_pm_enter();
 120         cpu_suspend(0, idle_finisher);
 121
 122 #ifdef CONFIG_SMP
 123         if (!soc_is_exynos5250())
 124                 scu_enable(S5P_VA_SCU);
 125 #endif
 126         cpu_pm_exit();
 127
 128         restore_cpu_arch_register();
 129
 130         /*
 131          * If PMU failed while entering sleep mode, WFI will be
 132          * ignored by PMU and then exiting cpu_do_idle().
 133          * S5P_CENTRAL_LOWPWR_CFG bit will not be set automatically
 134          * in this situation.
 135          */
 136         tmp = __raw_readl(S5P_CENTRAL_SEQ_CONFIGURATION);
 137         if (!(tmp & S5P_CENTRAL_LOWPWR_CFG)) {
 138                 tmp |= S5P_CENTRAL_LOWPWR_CFG;
 139                 __raw_writel(tmp, S5P_CENTRAL_SEQ_CONFIGURATION);
 140         }
 141
 142         /* Clear wakeup state register */
 143         __raw_writel(0x0, S5P_WAKEUP_STAT);
 144
 145         return index;
 146 }
 147
 148 static int exynos4_enter_lowpower(struct cpuidle_device *dev,
 149                                 struct cpuidle_driver *drv,
 150                                 int index)
 151 {
 152         int new_index = index;
 153
 154         /* This mode only can be entered when other core's are offline */
 155         if (num_online_cpus() > 1)
 156                 new_index = drv->safe_state_index;
 157
 158         if (new_index == 0)
 159                 return arm_cpuidle_simple_enter(dev, drv, new_index);
 160         else
 161                 return exynos4_enter_core0_aftr(dev, drv, new_index);
 162 }
 163
 164 static void __init exynos5_core_down_clk(void)
 165 {
 166         unsigned int tmp;
 167
 168         /*
 169          * Enable arm clock down (in idle) and set arm divider
 170          * ratios in WFI/WFE state.
 171          */
 172         tmp = PWR_CTRL1_CORE2_DOWN_RATIO | \
 173               PWR_CTRL1_CORE1_DOWN_RATIO | \
 174               PWR_CTRL1_DIV2_DOWN_EN     | \
 175               PWR_CTRL1_DIV1_DOWN_EN     | \
 176               PWR_CTRL1_USE_CORE1_WFE    | \
 177               PWR_CTRL1_USE_CORE0_WFE    | \
 178               PWR_CTRL1_USE_CORE1_WFI    | \
 179               PWR_CTRL1_USE_CORE0_WFI;
 180         __raw_writel(tmp, EXYNOS5_PWR_CTRL1);
 181
 182         /*
 183          * Enable arm clock up (on exiting idle). Set arm divider
 184          * ratios when not in idle along with the standby duration
 185          * ratios.
 186          */
 187         tmp = PWR_CTRL2_DIV2_UP_EN       | \
 188               PWR_CTRL2_DIV1_UP_EN       | \
 189               PWR_CTRL2_DUR_STANDBY2_VAL | \
 190               PWR_CTRL2_DUR_STANDBY1_VAL | \
 191               PWR_CTRL2_CORE2_UP_RATIO   | \
 192               PWR_CTRL2_CORE1_UP_RATIO;
 193         __raw_writel(tmp, EXYNOS5_PWR_CTRL2);
 194 }
 195
 196 static int exynos_cpuidle_probe(struct platform_device *pdev)
 197 {
 198         int cpu_id, ret;
 199         struct cpuidle_device *device;
 200
 201         if (soc_is_exynos5250())
 202                 exynos5_core_down_clk();
 203
 204         if (soc_is_exynos5440())
 205                 exynos4_idle_driver.state_count = 1;
 206
 207         ret = cpuidle_register_driver(&exynos4_idle_driver);
 208         if (ret) {
 209                 dev_err(&pdev->dev, "failed to register cpuidle driver\n");
 210                 return ret;
 211         }
 212
 213         for_each_online_cpu(cpu_id) {
 214                 device = &per_cpu(exynos4_cpuidle_device, cpu_id);
 215                 device->cpu = cpu_id;
 216
 217                 /* Support IDLE only */
 218                 if (cpu_id != 0)
 219                         device->state_count = 1;
 220
 221                 ret = cpuidle_register_device(device);
 222                 if (ret) {
 223                         dev_err(&pdev->dev, "failed to register cpuidle device\n");
 224                         return ret;
 225                 }
 226         }
 227
 228         return 0;
 229 }
 230
 231 static struct platform_driver exynos_cpuidle_driver = {
 232         .probe  = exynos_cpuidle_probe,
 233         .driver = {
 234                 .name = "exynos_cpuidle",
 235                 .owner = THIS_MODULE,
 236         },
 237 };
 238
 239 module_platform_driver(exynos_cpuidle_driver);