arch/arm/mach-omap2/pm44xx.c

   1 /*
   2  * OMAP4 Power Management Routines
   3  *
   4  * Copyright (C) 2010 Texas Instruments, Inc.
   5  * Rajendra Nayak <rnayak@ti.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/pm.h>
  13 #include <linux/suspend.h>
  14 #include <linux/module.h>
  15 #include <linux/list.h>
  16 #include <linux/err.h>
  17 #include <linux/slab.h>
  18
  19 #include "common.h"
  20 #include "powerdomain.h"
  21
  22 struct power_state {
  23         struct powerdomain *pwrdm;
  24         u32 next_state;
  25 #ifdef CONFIG_SUSPEND
  26         u32 saved_state;
  27 #endif
  28         struct list_head node;
  29 };
  30
  31 static LIST_HEAD(pwrst_list);
  32
  33 #ifdef CONFIG_SUSPEND
  34 static int omap4_pm_suspend(void)
  35 {
  36         do_wfi();
  37         return 0;
  38 }
  39
  40 static int omap4_pm_enter(suspend_state_t suspend_state)
  41 {
  42         int ret = 0;
  43
  44         switch (suspend_state) {
  45         case PM_SUSPEND_STANDBY:
  46         case PM_SUSPEND_MEM:
  47                 ret = omap4_pm_suspend();
  48                 break;
  49         default:
  50                 ret = -EINVAL;
  51         }
  52
  53         return ret;
  54 }
  55
  56 static int omap4_pm_begin(suspend_state_t state)
  57 {
  58         disable_hlt();
  59         return 0;
  60 }
  61
  62 static void omap4_pm_end(void)
  63 {
  64         enable_hlt();
  65         return;
  66 }
  67
  68 static const struct platform_suspend_ops omap_pm_ops = {
  69         .begin          = omap4_pm_begin,
  70         .end            = omap4_pm_end,
  71         .enter          = omap4_pm_enter,
  72         .valid          = suspend_valid_only_mem,
  73 };
  74 #endif /* CONFIG_SUSPEND */
  75
  76 static int __init pwrdms_setup(struct powerdomain *pwrdm, void *unused)
  77 {
  78         struct power_state *pwrst;
  79
  80         if (!pwrdm->pwrsts)
  81                 return 0;
  82
  83         pwrst = kmalloc(sizeof(struct power_state), GFP_ATOMIC);
  84         if (!pwrst)
  85                 return -ENOMEM;
  86         pwrst->pwrdm = pwrdm;
  87         pwrst->next_state = PWRDM_POWER_ON;
  88         list_add(&pwrst->node, &pwrst_list);
  89
  90         return pwrdm_set_next_pwrst(pwrst->pwrdm, pwrst->next_state);
  91 }
  92
  93 /**
  94  * omap4_pm_init - Init routine for OMAP4 PM
  95  *
  96  * Initializes all powerdomain and clockdomain target states
  97  * and all PRCM settings.
  98  */
  99 static int __init omap4_pm_init(void)
 100 {
 101         int ret;
 102         struct clockdomain *emif_clkdm, *mpuss_clkdm, *l3_1_clkdm;
 103         struct clockdomain *ducati_clkdm, *l3_2_clkdm, *l4_per_clkdm;
 104
 105         if (!cpu_is_omap44xx())
 106                 return -ENODEV;
 107
 108         pr_err("Power Management for TI OMAP4.\n");
 109
 110         ret = pwrdm_for_each(pwrdms_setup, NULL);
 111         if (ret) {
 112                 pr_err("Failed to setup powerdomains\n");
 113                 goto err2;
 114         }
 115
 116         /*
 117          * The dynamic dependency between MPUSS -> MEMIF and
 118          * MPUSS -> L4_PER/L3_* and DUCATI -> L3_* doesn't work as
 119          * expected. The hardware recommendation is to enable static
 120          * dependencies for these to avoid system lock ups or random crashes.
 121          */
 122         mpuss_clkdm = clkdm_lookup("mpuss_clkdm");
 123         emif_clkdm = clkdm_lookup("l3_emif_clkdm");
 124         l3_1_clkdm = clkdm_lookup("l3_1_clkdm");
 125         l3_2_clkdm = clkdm_lookup("l3_2_clkdm");
 126         l4_per_clkdm = clkdm_lookup("l4_per_clkdm");
 127         ducati_clkdm = clkdm_lookup("ducati_clkdm");
 128         if ((!mpuss_clkdm) || (!emif_clkdm) || (!l3_1_clkdm) ||
 129                 (!l3_2_clkdm) || (!ducati_clkdm) || (!l4_per_clkdm))
 130                 goto err2;
 131
 132         ret = clkdm_add_wkdep(mpuss_clkdm, emif_clkdm);
 133         ret |= clkdm_add_wkdep(mpuss_clkdm, l3_1_clkdm);
 134         ret |= clkdm_add_wkdep(mpuss_clkdm, l3_2_clkdm);
 135         ret |= clkdm_add_wkdep(mpuss_clkdm, l4_per_clkdm);
 136         ret |= clkdm_add_wkdep(ducati_clkdm, l3_1_clkdm);
 137         ret |= clkdm_add_wkdep(ducati_clkdm, l3_2_clkdm);
 138         if (ret) {
 139                 pr_err("Failed to add MPUSS -> L3/EMIF/L4PER, DUCATI -> L3 "
 140                                 "wakeup dependency\n");
 141                 goto err2;
 142         }
 143
 144 #ifdef CONFIG_SUSPEND
 145         suspend_set_ops(&omap_pm_ops);
 146 #endif /* CONFIG_SUSPEND */
 147
 148 err2:
 149         return ret;
 150 }
 151 late_initcall(omap4_pm_init);