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 } 215