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
  19 #include <asm/proc-fns.h>
  20 #include <asm/smp_scu.h>
  21 #include <asm/suspend.h>
  22 #include <asm/unified.h>
  23 #include <asm/cpuidle.h>
  24 #include <mach/regs-clock.h>
  25 #include <mach/regs-pmu.h>
  26
  27 #include <plat/cpu.h>
  28
  29 #include "common.h"
  30
  31 #define REG_DIRECTGO_ADDR       (samsung_rev() == EXYNOS4210_REV_1_1 ? \
  32                         S5P_INFORM7 : (samsung_rev() == EXYNOS4210_REV_1_0 ? \
  33                         (S5P_VA_SYSRAM + 0x24) : S5P_INFORM0))
  34 #define REG_DIRECTGO_FLAG       (samsung_rev() == EXYNOS4210_REV_1_1 ? \
  35                         S5P_INFORM6 : (samsung_rev() == EXYNOS4210_REV_1_0 ? \
  36                         (S5P_VA_SYSRAM + 0x20) : S5P_INFORM1))
  37
  38 #define S5P_CHECK_AFTR          0xFCBA0D10
  39
  40 static int exynos4_enter_lowpower(struct cpuidle_device *dev,
  41                                 struct cpuidle_driver *drv,
  42                                 int index);
  43
  44 static struct cpuidle_state exynos4_cpuidle_set[] __initdata = {
  45         [0] = ARM_CPUIDLE_WFI_STATE,
  46         [1] = {
  47                 .enter                  = exynos4_enter_lowpower,
  48                 .exit_latency           = 300,
  49                 .target_residency       = 100000,
  50                 .flags                  = CPUIDLE_FLAG_TIME_VALID,
  51                 .name                   = "C1",
  52                 .desc                   = "ARM power down",
  53         },
  54 };
  55
  56 static DEFINE_PER_CPU(struct cpuidle_device, exynos4_cpuidle_device);
  57
  58 static struct cpuidle_driver exynos4_idle_driver = {
  59         .name                   = "exynos4_idle",
  60         .owner                  = THIS_MODULE,
  61 };
  62
  63 /* Ext-GIC nIRQ/nFIQ is the only wakeup source in AFTR */
  64 static void exynos4_set_wakeupmask(void)
  65 {
  66         __raw_writel(0x0000ff3e, S5P_WAKEUP_MASK);
  67 }
  68
  69 static unsigned int g_pwr_ctrl, g_diag_reg;
  70
  71 static void save_cpu_arch_register(void)
  72 {
  73         /*read power control register*/
  74         asm("mrc p15, 0, %0, c15, c0, 0" : "=r"(g_pwr_ctrl) : : "cc");
  75         /*read diagnostic register*/
  76         asm("mrc p15, 0, %0, c15, c0, 1" : "=r"(g_diag_reg) : : "cc");
  77         return;
  78 }
  79
  80 static void restore_cpu_arch_register(void)
  81 {
  82         /*write power control register*/
  83         asm("mcr p15, 0, %0, c15, c0, 0" : : "r"(g_pwr_ctrl) : "cc");
  84         /*write diagnostic register*/
  85         asm("mcr p15, 0, %0, c15, c0, 1" : : "r"(g_diag_reg) : "cc");
  86         return;
  87 }
  88
  89 static int idle_finisher(unsigned long flags)
  90 {
  91         cpu_do_idle();
  92         return 1;
  93 }
  94
  95 static int exynos4_enter_core0_aftr(struct cpuidle_device *dev,
  96                                 struct cpuidle_driver *drv,
  97                                 int index)
  98 {
  99         unsigned long tmp;
 100
 101         exynos4_set_wakeupmask();
 102
 103         /* Set value of power down register for aftr mode */
 104         exynos_sys_powerdown_conf(SYS_AFTR);
 105
 106         __raw_writel(virt_to_phys(s3c_cpu_resume), REG_DIRECTGO_ADDR);
 107         __raw_writel(S5P_CHECK_AFTR, REG_DIRECTGO_FLAG);
 108
 109         save_cpu_arch_register();
 110
 111         /* Setting Central Sequence Register for power down mode */
 112         tmp = __raw_readl(S5P_CENTRAL_SEQ_CONFIGURATION);
 113         tmp &= ~S5P_CENTRAL_LOWPWR_CFG;
 114         __raw_writel(tmp, S5P_CENTRAL_SEQ_CONFIGURATION);
 115
 116         cpu_pm_enter();
 117         cpu_suspend(0, idle_finisher);
 118
 119 #ifdef CONFIG_SMP
 120         if (!soc_is_exynos5250())
 121                 scu_enable(S5P_VA_SCU);
 122 #endif
 123         cpu_pm_exit();
 124
 125         restore_cpu_arch_register();
 126
 127         /*
 128          * If PMU failed while entering sleep mode, WFI will be
 129          * ignored by PMU and then exiting cpu_do_idle().
 130          * S5P_CENTRAL_LOWPWR_CFG bit will not be set automatically
 131          * in this situation.
 132          */
 133         tmp = __raw_readl(S5P_CENTRAL_SEQ_CONFIGURATION);
 134         if (!(tmp & S5P_CENTRAL_LOWPWR_CFG)) {
 135                 tmp |= S5P_CENTRAL_LOWPWR_CFG;
 136                 __raw_writel(tmp, S5P_CENTRAL_SEQ_CONFIGURATION);
 137         }
 138
 139         /* Clear wakeup state register */
 140         __raw_writel(0x0, S5P_WAKEUP_STAT);
 141
 142         return index;
 143 }
 144
 145 static int exynos4_enter_lowpower(struct cpuidle_device *dev,
 146                                 struct cpuidle_driver *drv,
 147                                 int index)
 148 {
 149         int new_index = index;
 150
 151         /* This mode only can be entered when other core's are offline */
 152         if (num_online_cpus() > 1)
 153                 new_index = drv->safe_state_index;
 154
 155         if (new_index == 0)
 156                 return arm_cpuidle_simple_enter(dev, drv, new_index);
 157         else
 158                 return exynos4_enter_core0_aftr(dev, drv, new_index);
 159 }
 160
 161 static void __init exynos5_core_down_clk(void)
 162 {
 163         unsigned int tmp;
 164
 165         /*
 166          * Enable arm clock down (in idle) and set arm divider
 167          * ratios in WFI/WFE state.
 168          */
 169         tmp = PWR_CTRL1_CORE2_DOWN_RATIO | \
 170               PWR_CTRL1_CORE1_DOWN_RATIO | \
 171               PWR_CTRL1_DIV2_DOWN_EN     | \
 172               PWR_CTRL1_DIV1_DOWN_EN     | \
 173               PWR_CTRL1_USE_CORE1_WFE    | \
 174               PWR_CTRL1_USE_CORE0_WFE    | \
 175               PWR_CTRL1_USE_CORE1_WFI    | \
 176               PWR_CTRL1_USE_CORE0_WFI;
 177         __raw_writel(tmp, EXYNOS5_PWR_CTRL1);
 178
 179         /*
 180          * Enable arm clock up (on exiting idle). Set arm divider
 181          * ratios when not in idle along with the standby duration
 182          * ratios.
 183          */
 184         tmp = PWR_CTRL2_DIV2_UP_EN       | \
 185               PWR_CTRL2_DIV1_UP_EN       | \
 186               PWR_CTRL2_DUR_STANDBY2_VAL | \
 187               PWR_CTRL2_DUR_STANDBY1_VAL | \
 188               PWR_CTRL2_CORE2_UP_RATIO   | \
 189               PWR_CTRL2_CORE1_UP_RATIO;
 190         __raw_writel(tmp, EXYNOS5_PWR_CTRL2);
 191 }
 192
 193 static int __init exynos4_init_cpuidle(void)
 194 {
 195         int i, max_cpuidle_state, cpu_id;
 196         struct cpuidle_device *device;
 197         struct cpuidle_driver *drv = &exynos4_idle_driver;
 198
 199         if (soc_is_exynos5250())
 200                 exynos5_core_down_clk();
 201
 202         /* Setup cpuidle driver */
 203         drv->state_count = (sizeof(exynos4_cpuidle_set) /
 204                                        sizeof(struct cpuidle_state));
 205         max_cpuidle_state = drv->state_count;
 206         for (i = 0; i < max_cpuidle_state; i++) {
 207                 memcpy(&drv->states[i], &exynos4_cpuidle_set[i],
 208                                 sizeof(struct cpuidle_state));
 209         }
 210         drv->safe_state_index = 0;
 211         cpuidle_register_driver(&exynos4_idle_driver);
 212
 213         for_each_cpu(cpu_id, cpu_online_mask) {
 214                 device = &per_cpu(exynos4_cpuidle_device, cpu_id);
 215                 device->cpu = cpu_id;
 216
 217                 if (cpu_id == 0)
 218                         device->state_count = (sizeof(exynos4_cpuidle_set) /
 219                                                sizeof(struct cpuidle_state));
 220                 else
 221                         device->state_count = 1;        /* Support IDLE only */
 222
 223                 if (cpuidle_register_device(device)) {
 224                         printk(KERN_ERR "CPUidle register device failed\n,");
 225                         return -EIO;
 226                 }
 227         }
 228
 229         return 0;
 230 }
 231 device_initcall(exynos4_init_cpuidle);