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