arch/arm/plat-samsung/pm.c

   1 /* linux/arch/arm/plat-s3c/pm.c
   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  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2 as
  12  * published by the Free Software Foundation.
  13 */
  14
  15 #include <linux/init.h>
  16 #include <linux/suspend.h>
  17 #include <linux/errno.h>
  18 #include <linux/delay.h>
  19 #include <linux/of.h>
  20 #include <linux/serial_s3c.h>
  21 #include <linux/io.h>
  22
  23 #include <asm/cacheflush.h>
  24 #include <asm/suspend.h>
  25
  26 #ifdef CONFIG_SAMSUNG_ATAGS
  27 #include <mach/map.h>
  28 #ifndef CONFIG_ARCH_EXYNOS
  29 #include <mach/regs-clock.h>
  30 #include <mach/regs-irq.h>
  31 #endif
  32 #include <mach/irqs.h>
  33 #endif
  34
  35 #include <asm/irq.h>
  36
  37 #include <plat/pm.h>
  38 #include <mach/pm-core.h>
  39
  40 /* for external use */
  41
  42 unsigned long s3c_pm_flags;
  43
  44 /* The IRQ ext-int code goes here, it is too small to currently bother
  45  * with its own file. */
  46
  47 unsigned long s3c_irqwake_intmask       = 0xffffffffL;
  48 unsigned long s3c_irqwake_eintmask      = 0xffffffffL;
  49
  50 int s3c_irqext_wake(struct irq_data *data, unsigned int state)
  51 {
  52         unsigned long bit = 1L << IRQ_EINT_BIT(data->irq);
  53
  54         if (!(s3c_irqwake_eintallow & bit))
  55                 return -ENOENT;
  56
  57         printk(KERN_INFO "wake %s for irq %d\n",
  58                state ? "enabled" : "disabled", data->irq);
  59
  60         if (!state)
  61                 s3c_irqwake_eintmask |= bit;
  62         else
  63                 s3c_irqwake_eintmask &= ~bit;
  64
  65         return 0;
  66 }
  67
  68 void (*pm_cpu_prep)(void);
  69 int (*pm_cpu_sleep)(unsigned long);
  70
  71 #define any_allowed(mask, allow) (((mask) & (allow)) != (allow))
  72
  73 /* s3c_pm_enter
  74  *
  75  * central control for sleep/resume process
  76 */
  77
  78 static int s3c_pm_enter(suspend_state_t state)
  79 {
  80         int ret;
  81         /* ensure the debug is initialised (if enabled) */
  82
  83         s3c_pm_debug_init();
  84
  85         S3C_PMDBG("%s(%d)\n", __func__, state);
  86
  87         if (pm_cpu_prep == NULL || pm_cpu_sleep == NULL) {
  88                 printk(KERN_ERR "%s: error: no cpu sleep function\n", __func__);
  89                 return -EINVAL;
  90         }
  91
  92         /* check if we have anything to wake-up with... bad things seem
  93          * to happen if you suspend with no wakeup (system will often
  94          * require a full power-cycle)
  95         */
  96
  97         if (!of_have_populated_dt() &&
  98             !any_allowed(s3c_irqwake_intmask, s3c_irqwake_intallow) &&
  99             !any_allowed(s3c_irqwake_eintmask, s3c_irqwake_eintallow)) {
 100                 printk(KERN_ERR "%s: No wake-up sources!\n", __func__);
 101                 printk(KERN_ERR "%s: Aborting sleep\n", __func__);
 102                 return -EINVAL;
 103         }
 104
 105         /* save all necessary core registers not covered by the drivers */
 106
 107         if (!of_have_populated_dt()) {
 108                 samsung_pm_save_gpios();
 109                 samsung_pm_saved_gpios();
 110         }
 111
 112         s3c_pm_save_uarts();
 113         s3c_pm_save_core();
 114
 115         /* set the irq configuration for wake */
 116
 117         s3c_pm_configure_extint();
 118
 119         S3C_PMDBG("sleep: irq wakeup masks: %08lx,%08lx\n",
 120             s3c_irqwake_intmask, s3c_irqwake_eintmask);
 121
 122         s3c_pm_arch_prepare_irqs();
 123
 124         /* call cpu specific preparation */
 125
 126         pm_cpu_prep();
 127
 128         /* flush cache back to ram */
 129
 130         flush_cache_all();
 131
 132         s3c_pm_check_store();
 133
 134         /* send the cpu to sleep... */
 135
 136         s3c_pm_arch_stop_clocks();
 137
 138         /* this will also act as our return point from when
 139          * we resume as it saves its own register state and restores it
 140          * during the resume.  */
 141
 142         ret = cpu_suspend(0, pm_cpu_sleep);
 143         if (ret)
 144                 return ret;
 145
 146         /* restore the system state */
 147
 148         s3c_pm_restore_core();
 149         s3c_pm_restore_uarts();
 150
 151         if (!of_have_populated_dt()) {
 152                 samsung_pm_restore_gpios();
 153                 s3c_pm_restored_gpios();
 154         }
 155
 156         s3c_pm_debug_init();
 157
 158         /* check what irq (if any) restored the system */
 159
 160         s3c_pm_arch_show_resume_irqs();
 161
 162         S3C_PMDBG("%s: post sleep, preparing to return\n", __func__);
 163
 164         /* LEDs should now be 1110 */
 165         s3c_pm_debug_smdkled(1 << 1, 0);
 166
 167         s3c_pm_check_restore();
 168
 169         /* ok, let's return from sleep */
 170
 171         S3C_PMDBG("S3C PM Resume (post-restore)\n");
 172         return 0;
 173 }
 174
 175 static int s3c_pm_prepare(void)
 176 {
 177         /* prepare check area if configured */
 178
 179         s3c_pm_check_prepare();
 180         return 0;
 181 }
 182
 183 static void s3c_pm_finish(void)
 184 {
 185         s3c_pm_check_cleanup();
 186 }
 187
 188 static const struct platform_suspend_ops s3c_pm_ops = {
 189         .enter          = s3c_pm_enter,
 190         .prepare        = s3c_pm_prepare,
 191         .finish         = s3c_pm_finish,
 192         .valid          = suspend_valid_only_mem,
 193 };
 194
 195 /* s3c_pm_init
 196  *
 197  * Attach the power management functions. This should be called
 198  * from the board specific initialisation if the board supports
 199  * it.
 200 */
 201
 202 int __init s3c_pm_init(void)
 203 {
 204         printk("S3C Power Management, Copyright 2004 Simtec Electronics\n");
 205
 206         suspend_set_ops(&s3c_pm_ops);
 207         return 0;
 208 }