arch/arm/mach-s5pv210/pm.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 //
   3 // Copyright (c) 2010-2014 Samsung Electronics Co., Ltd.
   4 //              http://www.samsung.com
   5 //
   6 // S5PV210 - Power Management support
   7 //
   8 // Based on arch/arm/mach-s3c2410/pm.c
   9 // Copyright (c) 2006 Simtec Electronics
  10 //      Ben Dooks <ben@simtec.co.uk>
  11
  12 #include <linux/init.h>
  13 #include <linux/suspend.h>
  14 #include <linux/syscore_ops.h>
  15 #include <linux/io.h>
  16 #include <linux/soc/samsung/s3c-pm.h>
  17
  18 #include <asm/cacheflush.h>
  19 #include <asm/suspend.h>
  20
  21 #include "common.h"
  22 #include "regs-clock.h"
  23
  24 /* helper functions to save and restore register state */
  25 struct sleep_save {
  26         void __iomem    *reg;
  27         unsigned long   val;
  28 };
  29
  30 #define SAVE_ITEM(x) \
  31         { .reg = (x) }
  32
  33 /**
  34  * s3c_pm_do_save() - save a set of registers for restoration on resume.
  35  * @ptr: Pointer to an array of registers.
  36  * @count: Size of the ptr array.
  37  *
  38  * Run through the list of registers given, saving their contents in the
  39  * array for later restoration when we wakeup.
  40  */
  41 static void s3c_pm_do_save(struct sleep_save *ptr, int count)
  42 {
  43         for (; count > 0; count--, ptr++) {
  44                 ptr->val = readl_relaxed(ptr->reg);
  45                 S3C_PMDBG("saved %p value %08lx\n", ptr->reg, ptr->val);
  46         }
  47 }
  48
  49 /**
  50  * s3c_pm_do_restore() - restore register values from the save list.
  51  * @ptr: Pointer to an array of registers.
  52  * @count: Size of the ptr array.
  53  *
  54  * Restore the register values saved from s3c_pm_do_save().
  55  *
  56  * WARNING: Do not put any debug in here that may effect memory or use
  57  * peripherals, as things may be changing!
  58 */
  59
  60 static void s3c_pm_do_restore_core(const struct sleep_save *ptr, int count)
  61 {
  62         for (; count > 0; count--, ptr++)
  63                 writel_relaxed(ptr->val, ptr->reg);
  64 }
  65
  66 static struct sleep_save s5pv210_core_save[] = {
  67         /* Clock ETC */
  68         SAVE_ITEM(S5P_MDNIE_SEL),
  69 };
  70
  71 /*
  72  * VIC wake-up support (TODO)
  73  */
  74 static u32 s5pv210_irqwake_intmask = 0xffffffff;
  75
  76 static u32 s5pv210_read_eint_wakeup_mask(void)
  77 {
  78         return __raw_readl(S5P_EINT_WAKEUP_MASK);
  79 }
  80
  81 /*
  82  * Suspend helpers.
  83  */
  84 static int s5pv210_cpu_suspend(unsigned long arg)
  85 {
  86         unsigned long tmp;
  87
  88         /* issue the standby signal into the pm unit. Note, we
  89          * issue a write-buffer drain just in case */
  90
  91         tmp = 0;
  92
  93         asm("b 1f\n\t"
  94             ".align 5\n\t"
  95             "1:\n\t"
  96             "mcr p15, 0, %0, c7, c10, 5\n\t"
  97             "mcr p15, 0, %0, c7, c10, 4\n\t"
  98             "wfi" : : "r" (tmp));
  99
 100         pr_info("Failed to suspend the system\n");
 101         return 1; /* Aborting suspend */
 102 }
 103
 104 static void s5pv210_pm_prepare(void)
 105 {
 106         unsigned int tmp;
 107
 108         /*
 109          * Set wake-up mask registers
 110          * S5P_EINT_WAKEUP_MASK is set by pinctrl driver in late suspend.
 111          */
 112         __raw_writel(s5pv210_irqwake_intmask, S5P_WAKEUP_MASK);
 113
 114         /* ensure at least INFORM0 has the resume address */
 115         __raw_writel(__pa_symbol(s5pv210_cpu_resume), S5P_INFORM0);
 116
 117         tmp = __raw_readl(S5P_SLEEP_CFG);
 118         tmp &= ~(S5P_SLEEP_CFG_OSC_EN | S5P_SLEEP_CFG_USBOSC_EN);
 119         __raw_writel(tmp, S5P_SLEEP_CFG);
 120
 121         /* WFI for SLEEP mode configuration by SYSCON */
 122         tmp = __raw_readl(S5P_PWR_CFG);
 123         tmp &= S5P_CFG_WFI_CLEAN;
 124         tmp |= S5P_CFG_WFI_SLEEP;
 125         __raw_writel(tmp, S5P_PWR_CFG);
 126
 127         /* SYSCON interrupt handling disable */
 128         tmp = __raw_readl(S5P_OTHERS);
 129         tmp |= S5P_OTHER_SYSC_INTOFF;
 130         __raw_writel(tmp, S5P_OTHERS);
 131
 132         s3c_pm_do_save(s5pv210_core_save, ARRAY_SIZE(s5pv210_core_save));
 133 }
 134
 135 /*
 136  * Suspend operations.
 137  */
 138 static int s5pv210_suspend_enter(suspend_state_t state)
 139 {
 140         u32 eint_wakeup_mask = s5pv210_read_eint_wakeup_mask();
 141         int ret;
 142
 143         S3C_PMDBG("%s: suspending the system...\n", __func__);
 144
 145         S3C_PMDBG("%s: wakeup masks: %08x,%08x\n", __func__,
 146                         s5pv210_irqwake_intmask, eint_wakeup_mask);
 147
 148         if (s5pv210_irqwake_intmask == -1U
 149             && eint_wakeup_mask == -1U) {
 150                 pr_err("%s: No wake-up sources!\n", __func__);
 151                 pr_err("%s: Aborting sleep\n", __func__);
 152                 return -EINVAL;
 153         }
 154
 155         s3c_pm_save_uarts(false);
 156         s5pv210_pm_prepare();
 157         flush_cache_all();
 158         s3c_pm_check_store();
 159
 160         ret = cpu_suspend(0, s5pv210_cpu_suspend);
 161         if (ret)
 162                 return ret;
 163
 164         s3c_pm_restore_uarts(false);
 165
 166         S3C_PMDBG("%s: wakeup stat: %08x\n", __func__,
 167                         __raw_readl(S5P_WAKEUP_STAT));
 168
 169         s3c_pm_check_restore();
 170
 171         S3C_PMDBG("%s: resuming the system...\n", __func__);
 172
 173         return 0;
 174 }
 175
 176 static int s5pv210_suspend_prepare(void)
 177 {
 178         s3c_pm_check_prepare();
 179
 180         return 0;
 181 }
 182
 183 static void s5pv210_suspend_finish(void)
 184 {
 185         s3c_pm_check_cleanup();
 186 }
 187
 188 static const struct platform_suspend_ops s5pv210_suspend_ops = {
 189         .enter          = s5pv210_suspend_enter,
 190         .prepare        = s5pv210_suspend_prepare,
 191         .finish         = s5pv210_suspend_finish,
 192         .valid          = suspend_valid_only_mem,
 193 };
 194
 195 /*
 196  * Syscore operations used to delay restore of certain registers.
 197  */
 198 static void s5pv210_pm_resume(void)
 199 {
 200         s3c_pm_do_restore_core(s5pv210_core_save, ARRAY_SIZE(s5pv210_core_save));
 201 }
 202
 203 static struct syscore_ops s5pv210_pm_syscore_ops = {
 204         .resume         = s5pv210_pm_resume,
 205 };
 206
 207 /*
 208  * Initialization entry point.
 209  */
 210 void __init s5pv210_pm_init(void)
 211 {
 212         register_syscore_ops(&s5pv210_pm_syscore_ops);
 213         suspend_set_ops(&s5pv210_suspend_ops);
 214 }