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 "clockdomain.h"
  21 #include "powerdomain.h"
  22
  23 struct power_state {
  24         struct powerdomain *pwrdm;
  25         u32 next_state;
  26 #ifdef CONFIG_SUSPEND
  27         u32 saved_state;
  28 #endif
  29         struct list_head node;
  30 };
  31
  32 static LIST_HEAD(pwrst_list);
  33
  34 #ifdef CONFIG_SUSPEND
  35 static int omap4_pm_suspend(void)
  36 {
  37         do_wfi();
  38         return 0;
  39 }
  40
  41 static int omap4_pm_enter(suspend_state_t suspend_state)
  42 {
  43         int ret = 0;
  44
  45         switch (suspend_state) {
  46         case PM_SUSPEND_STANDBY:
  47         case PM_SUSPEND_MEM:
  48                 ret = omap4_pm_suspend();
  49                 break;
  50         default:
  51                 ret = -EINVAL;
  52         }
  53
  54         return ret;
  55 }
  56
  57 static int omap4_pm_begin(suspend_state_t state)
  58 {
  59         disable_hlt();
  60         return 0;
  61 }
  62
  63 static void omap4_pm_end(void)
  64 {
  65         enable_hlt();
  66         return;
  67 }
  68
  69 static const struct platform_suspend_ops omap_pm_ops = {
  70         .begin          = omap4_pm_begin,
  71         .end            = omap4_pm_end,
  72         .enter          = omap4_pm_enter,
  73         .valid          = suspend_valid_only_mem,
  74 };
  75 #endif /* CONFIG_SUSPEND */
  76
  77 /*
  78  * Enable hardware supervised mode for all clockdomains if it's
  79  * supported. Initiate sleep transition for other clockdomains, if
  80  * they are not used
  81  */
  82 static int __init clkdms_setup(struct clockdomain *clkdm, void *unused)
  83 {
  84         if (clkdm->flags & CLKDM_CAN_ENABLE_AUTO)
  85                 clkdm_allow_idle(clkdm);
  86         else if (clkdm->flags & CLKDM_CAN_FORCE_SLEEP &&
  87                         atomic_read(&clkdm->usecount) == 0)
  88                 clkdm_sleep(clkdm);
  89         return 0;
  90 }
  91
  92
  93 static int __init pwrdms_setup(struct powerdomain *pwrdm, void *unused)
  94 {
  95         struct power_state *pwrst;
  96
  97         if (!pwrdm->pwrsts)
  98                 return 0;
  99
 100         pwrst = kmalloc(sizeof(struct power_state), GFP_ATOMIC);
 101         if (!pwrst)
 102                 return -ENOMEM;
 103         pwrst->pwrdm = pwrdm;
 104         pwrst->next_state = PWRDM_POWER_ON;
 105         list_add(&pwrst->node, &pwrst_list);
 106
 107         return pwrdm_set_next_pwrst(pwrst->pwrdm, pwrst->next_state);
 108 }
 109
 110 /**
 111  * omap4_pm_init - Init routine for OMAP4 PM
 112  *
 113  * Initializes all powerdomain and clockdomain target states
 114  * and all PRCM settings.
 115  */
 116 static int __init omap4_pm_init(void)
 117 {
 118         int ret;
 119         struct clockdomain *emif_clkdm, *mpuss_clkdm, *l3_1_clkdm;
 120         struct clockdomain *ducati_clkdm, *l3_2_clkdm, *l4_per_clkdm;
 121
 122         if (!cpu_is_omap44xx())
 123                 return -ENODEV;
 124
 125         if (omap_rev() == OMAP4430_REV_ES1_0) {
 126                 WARN(1, "Power Management not supported on OMAP4430 ES1.0\n");
 127                 return -ENODEV;
 128         }
 129
 130         pr_err("Power Management for TI OMAP4.\n");
 131
 132         ret = pwrdm_for_each(pwrdms_setup, NULL);
 133         if (ret) {
 134                 pr_err("Failed to setup powerdomains\n");
 135                 goto err2;
 136         }
 137
 138         /*
 139          * The dynamic dependency between MPUSS -> MEMIF and
 140          * MPUSS -> L4_PER/L3_* and DUCATI -> L3_* doesn't work as
 141          * expected. The hardware recommendation is to enable static
 142          * dependencies for these to avoid system lock ups or random crashes.
 143          */
 144         mpuss_clkdm = clkdm_lookup("mpuss_clkdm");
 145         emif_clkdm = clkdm_lookup("l3_emif_clkdm");
 146         l3_1_clkdm = clkdm_lookup("l3_1_clkdm");
 147         l3_2_clkdm = clkdm_lookup("l3_2_clkdm");
 148         l4_per_clkdm = clkdm_lookup("l4_per_clkdm");
 149         ducati_clkdm = clkdm_lookup("ducati_clkdm");
 150         if ((!mpuss_clkdm) || (!emif_clkdm) || (!l3_1_clkdm) ||
 151                 (!l3_2_clkdm) || (!ducati_clkdm) || (!l4_per_clkdm))
 152                 goto err2;
 153
 154         ret = clkdm_add_wkdep(mpuss_clkdm, emif_clkdm);
 155         ret |= clkdm_add_wkdep(mpuss_clkdm, l3_1_clkdm);
 156         ret |= clkdm_add_wkdep(mpuss_clkdm, l3_2_clkdm);
 157         ret |= clkdm_add_wkdep(mpuss_clkdm, l4_per_clkdm);
 158         ret |= clkdm_add_wkdep(ducati_clkdm, l3_1_clkdm);
 159         ret |= clkdm_add_wkdep(ducati_clkdm, l3_2_clkdm);
 160         if (ret) {
 161                 pr_err("Failed to add MPUSS -> L3/EMIF/L4PER, DUCATI -> L3 "
 162                                 "wakeup dependency\n");
 163                 goto err2;
 164         }
 165
 166         (void) clkdm_for_each(clkdms_setup, NULL);
 167
 168 #ifdef CONFIG_SUSPEND
 169         suspend_set_ops(&omap_pm_ops);
 170 #endif /* CONFIG_SUSPEND */
 171
 172 err2:
 173         return ret;
 174 }
 175 late_initcall(omap4_pm_init);