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 /* s3c2410_pm_show_resume_irqs
  69  *
  70  * print any IRQs asserted at resume time (ie, we woke from)
  71 */
  72 static void __maybe_unused s3c_pm_show_resume_irqs(int start,
  73                                                    unsigned long which,
  74                                                    unsigned long mask)
  75 {
  76         int i;
  77
  78         which &= ~mask;
  79
  80         for (i = 0; i <= 31; i++) {
  81                 if (which & (1L<<i)) {
  82                         S3C_PMDBG("IRQ %d asserted at resume\n", start+i);
  83                 }
  84         }
  85 }
  86
  87
  88 void (*pm_cpu_prep)(void);
  89 int (*pm_cpu_sleep)(unsigned long);
  90
  91 #define any_allowed(mask, allow) (((mask) & (allow)) != (allow))
  92
  93 /* s3c_pm_enter
  94  *
  95  * central control for sleep/resume process
  96 */
  97
  98 static int s3c_pm_enter(suspend_state_t state)
  99 {
 100         int ret;
 101         /* ensure the debug is initialised (if enabled) */
 102
 103         s3c_pm_debug_init();
 104
 105         S3C_PMDBG("%s(%d)\n", __func__, state);
 106
 107         if (pm_cpu_prep == NULL || pm_cpu_sleep == NULL) {
 108                 printk(KERN_ERR "%s: error: no cpu sleep function\n", __func__);
 109                 return -EINVAL;
 110         }
 111
 112         /* check if we have anything to wake-up with... bad things seem
 113          * to happen if you suspend with no wakeup (system will often
 114          * require a full power-cycle)
 115         */
 116
 117         if (!of_have_populated_dt() &&
 118             !any_allowed(s3c_irqwake_intmask, s3c_irqwake_intallow) &&
 119             !any_allowed(s3c_irqwake_eintmask, s3c_irqwake_eintallow)) {
 120                 printk(KERN_ERR "%s: No wake-up sources!\n", __func__);
 121                 printk(KERN_ERR "%s: Aborting sleep\n", __func__);
 122                 return -EINVAL;
 123         }
 124
 125         /* save all necessary core registers not covered by the drivers */
 126
 127         if (!of_have_populated_dt()) {
 128                 samsung_pm_save_gpios();
 129                 samsung_pm_saved_gpios();
 130         }
 131
 132         s3c_pm_save_uarts();
 133         s3c_pm_save_core();
 134
 135         /* set the irq configuration for wake */
 136
 137         s3c_pm_configure_extint();
 138
 139         S3C_PMDBG("sleep: irq wakeup masks: %08lx,%08lx\n",
 140             s3c_irqwake_intmask, s3c_irqwake_eintmask);
 141
 142         s3c_pm_arch_prepare_irqs();
 143
 144         /* call cpu specific preparation */
 145
 146         pm_cpu_prep();
 147
 148         /* flush cache back to ram */
 149
 150         flush_cache_all();
 151
 152         s3c_pm_check_store();
 153
 154         /* send the cpu to sleep... */
 155
 156         s3c_pm_arch_stop_clocks();
 157
 158         /* this will also act as our return point from when
 159          * we resume as it saves its own register state and restores it
 160          * during the resume.  */
 161
 162         ret = cpu_suspend(0, pm_cpu_sleep);
 163         if (ret)
 164                 return ret;
 165
 166         /* restore the system state */
 167
 168         s3c_pm_restore_core();
 169         s3c_pm_restore_uarts();
 170
 171         if (!of_have_populated_dt()) {
 172                 samsung_pm_restore_gpios();
 173                 s3c_pm_restored_gpios();
 174         }
 175
 176         s3c_pm_debug_init();
 177
 178         /* check what irq (if any) restored the system */
 179
 180         s3c_pm_arch_show_resume_irqs();
 181
 182         S3C_PMDBG("%s: post sleep, preparing to return\n", __func__);
 183
 184         /* LEDs should now be 1110 */
 185         s3c_pm_debug_smdkled(1 << 1, 0);
 186
 187         s3c_pm_check_restore();
 188
 189         /* ok, let's return from sleep */
 190
 191         S3C_PMDBG("S3C PM Resume (post-restore)\n");
 192         return 0;
 193 }
 194
 195 static int s3c_pm_prepare(void)
 196 {
 197         /* prepare check area if configured */
 198
 199         s3c_pm_check_prepare();
 200         return 0;
 201 }
 202
 203 static void s3c_pm_finish(void)
 204 {
 205         s3c_pm_check_cleanup();
 206 }
 207
 208 static const struct platform_suspend_ops s3c_pm_ops = {
 209         .enter          = s3c_pm_enter,
 210         .prepare        = s3c_pm_prepare,
 211         .finish         = s3c_pm_finish,
 212         .valid          = suspend_valid_only_mem,
 213 };
 214
 215 /* s3c_pm_init
 216  *
 217  * Attach the power management functions. This should be called
 218  * from the board specific initialisation if the board supports
 219  * it.
 220 */
 221
 222 int __init s3c_pm_init(void)
 223 {
 224         printk("S3C Power Management, Copyright 2004 Simtec Electronics\n");
 225
 226         suspend_set_ops(&s3c_pm_ops);
 227         return 0;
 228 }