arch/arm/plat-samsung/pm.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 //
   3 // Copyright 2008 Openmoko, Inc.
   4 // Copyright 2004-2008 Simtec Electronics
   5 //      Ben Dooks <ben@simtec.co.uk>
   6 //      http://armlinux.simtec.co.uk/
   7 //
   8 // S3C common power management (suspend to ram) support.
   9
  10 #include <linux/init.h>
  11 #include <linux/suspend.h>
  12 #include <linux/errno.h>
  13 #include <linux/delay.h>
  14 #include <linux/of.h>
  15 #include <linux/serial_s3c.h>
  16 #include <linux/io.h>
  17
  18 #include <asm/cacheflush.h>
  19 #include <asm/suspend.h>
  20
  21 #include <mach/map.h>
  22 #include <mach/regs-clock.h>
  23 #include <mach/regs-irq.h>
  24 #include <mach/irqs.h>
  25
  26 #include <asm/irq.h>
  27
  28 #include <plat/pm.h>
  29 #include <mach/pm-core.h>
  30
  31 /* for external use */
  32
  33 unsigned long s3c_pm_flags;
  34
  35 /* The IRQ ext-int code goes here, it is too small to currently bother
  36  * with its own file. */
  37
  38 unsigned long s3c_irqwake_intmask       = 0xffffffffL;
  39 unsigned long s3c_irqwake_eintmask      = 0xffffffffL;
  40
  41 int s3c_irqext_wake(struct irq_data *data, unsigned int state)
  42 {
  43         unsigned long bit = 1L << IRQ_EINT_BIT(data->irq);
  44
  45         if (!(s3c_irqwake_eintallow & bit))
  46                 return -ENOENT;
  47
  48         printk(KERN_INFO "wake %s for irq %d\n",
  49                state ? "enabled" : "disabled", data->irq);
  50
  51         if (!state)
  52                 s3c_irqwake_eintmask |= bit;
  53         else
  54                 s3c_irqwake_eintmask &= ~bit;
  55
  56         return 0;
  57 }
  58
  59 void (*pm_cpu_prep)(void);
  60 int (*pm_cpu_sleep)(unsigned long);
  61
  62 #define any_allowed(mask, allow) (((mask) & (allow)) != (allow))
  63
  64 /* s3c_pm_enter
  65  *
  66  * central control for sleep/resume process
  67 */
  68
  69 static int s3c_pm_enter(suspend_state_t state)
  70 {
  71         int ret;
  72         /* ensure the debug is initialised (if enabled) */
  73
  74         s3c_pm_debug_init();
  75
  76         S3C_PMDBG("%s(%d)\n", __func__, state);
  77
  78         if (pm_cpu_prep == NULL || pm_cpu_sleep == NULL) {
  79                 printk(KERN_ERR "%s: error: no cpu sleep function\n", __func__);
  80                 return -EINVAL;
  81         }
  82
  83         /* check if we have anything to wake-up with... bad things seem
  84          * to happen if you suspend with no wakeup (system will often
  85          * require a full power-cycle)
  86         */
  87
  88         if (!of_have_populated_dt() &&
  89             !any_allowed(s3c_irqwake_intmask, s3c_irqwake_intallow) &&
  90             !any_allowed(s3c_irqwake_eintmask, s3c_irqwake_eintallow)) {
  91                 printk(KERN_ERR "%s: No wake-up sources!\n", __func__);
  92                 printk(KERN_ERR "%s: Aborting sleep\n", __func__);
  93                 return -EINVAL;
  94         }
  95
  96         /* save all necessary core registers not covered by the drivers */
  97
  98         if (!of_have_populated_dt()) {
  99                 samsung_pm_save_gpios();
 100                 samsung_pm_saved_gpios();
 101         }
 102
 103         s3c_pm_save_uarts();
 104         s3c_pm_save_core();
 105
 106         /* set the irq configuration for wake */
 107
 108         s3c_pm_configure_extint();
 109
 110         S3C_PMDBG("sleep: irq wakeup masks: %08lx,%08lx\n",
 111             s3c_irqwake_intmask, s3c_irqwake_eintmask);
 112
 113         s3c_pm_arch_prepare_irqs();
 114
 115         /* call cpu specific preparation */
 116
 117         pm_cpu_prep();
 118
 119         /* flush cache back to ram */
 120
 121         flush_cache_all();
 122
 123         s3c_pm_check_store();
 124
 125         /* send the cpu to sleep... */
 126
 127         s3c_pm_arch_stop_clocks();
 128
 129         /* this will also act as our return point from when
 130          * we resume as it saves its own register state and restores it
 131          * during the resume.  */
 132
 133         ret = cpu_suspend(0, pm_cpu_sleep);
 134         if (ret)
 135                 return ret;
 136
 137         /* restore the system state */
 138
 139         s3c_pm_restore_core();
 140         s3c_pm_restore_uarts();
 141
 142         if (!of_have_populated_dt()) {
 143                 samsung_pm_restore_gpios();
 144                 s3c_pm_restored_gpios();
 145         }
 146
 147         s3c_pm_debug_init();
 148
 149         /* check what irq (if any) restored the system */
 150
 151         s3c_pm_arch_show_resume_irqs();
 152
 153         S3C_PMDBG("%s: post sleep, preparing to return\n", __func__);
 154
 155         /* LEDs should now be 1110 */
 156         s3c_pm_debug_smdkled(1 << 1, 0);
 157
 158         s3c_pm_check_restore();
 159
 160         /* ok, let's return from sleep */
 161
 162         S3C_PMDBG("S3C PM Resume (post-restore)\n");
 163         return 0;
 164 }
 165
 166 static int s3c_pm_prepare(void)
 167 {
 168         /* prepare check area if configured */
 169
 170         s3c_pm_check_prepare();
 171         return 0;
 172 }
 173
 174 static void s3c_pm_finish(void)
 175 {
 176         s3c_pm_check_cleanup();
 177 }
 178
 179 static const struct platform_suspend_ops s3c_pm_ops = {
 180         .enter          = s3c_pm_enter,
 181         .prepare        = s3c_pm_prepare,
 182         .finish         = s3c_pm_finish,
 183         .valid          = suspend_valid_only_mem,
 184 };
 185
 186 /* s3c_pm_init
 187  *
 188  * Attach the power management functions. This should be called
 189  * from the board specific initialisation if the board supports
 190  * it.
 191 */
 192
 193 int __init s3c_pm_init(void)
 194 {
 195         printk("S3C Power Management, Copyright 2004 Simtec Electronics\n");
 196
 197         suspend_set_ops(&s3c_pm_ops);
 198         return 0;
 199 }