arch/arm/mach-omap2/pm44xx.c

   1 /*
   2  * OMAP4 Power Management Routines
   3  *
   4  * Copyright (C) 2010-2011 Texas Instruments, Inc.
   5  * Rajendra Nayak <rnayak@ti.com>
   6  * Santosh Shilimkar <santosh.shilimkar@ti.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12
  13 #include <linux/pm.h>
  14 #include <linux/suspend.h>
  15 #include <linux/module.h>
  16 #include <linux/list.h>
  17 #include <linux/err.h>
  18 #include <linux/slab.h>
  19 #include <asm/system_misc.h>
  20
  21 #include "soc.h"
  22 #include "common.h"
  23 #include "clockdomain.h"
  24 #include "powerdomain.h"
  25 #include "pm.h"
  26
  27 struct power_state {
  28         struct powerdomain *pwrdm;
  29         u32 next_state;
  30 #ifdef CONFIG_SUSPEND
  31         u32 saved_state;
  32         u32 saved_logic_state;
  33 #endif
  34         struct list_head node;
  35 };
  36
  37 static LIST_HEAD(pwrst_list);
  38
  39 #ifdef CONFIG_SUSPEND
  40 static int omap4_pm_suspend(void)
  41 {
  42         struct power_state *pwrst;
  43         int state, ret = 0;
  44         u32 cpu_id = smp_processor_id();
  45
  46         /* Save current powerdomain state */
  47         list_for_each_entry(pwrst, &pwrst_list, node) {
  48                 pwrst->saved_state = pwrdm_read_next_pwrst(pwrst->pwrdm);
  49                 pwrst->saved_logic_state = pwrdm_read_logic_retst(pwrst->pwrdm);
  50         }
  51
  52         /* Set targeted power domain states by suspend */
  53         list_for_each_entry(pwrst, &pwrst_list, node) {
  54                 omap_set_pwrdm_state(pwrst->pwrdm, pwrst->next_state);
  55                 pwrdm_set_logic_retst(pwrst->pwrdm, PWRDM_POWER_OFF);
  56         }
  57
  58         /*
  59          * For MPUSS to hit power domain retention(CSWR or OSWR),
  60          * CPU0 and CPU1 power domains need to be in OFF or DORMANT state,
  61          * since CPU power domain CSWR is not supported by hardware
  62          * Only master CPU follows suspend path. All other CPUs follow
  63          * CPU hotplug path in system wide suspend. On OMAP4, CPU power
  64          * domain CSWR is not supported by hardware.
  65          * More details can be found in OMAP4430 TRM section 4.3.4.2.
  66          */
  67         omap4_enter_lowpower(cpu_id, PWRDM_POWER_OFF);
  68
  69         /* Restore next powerdomain state */
  70         list_for_each_entry(pwrst, &pwrst_list, node) {
  71                 state = pwrdm_read_prev_pwrst(pwrst->pwrdm);
  72                 if (state > pwrst->next_state) {
  73                         pr_info("Powerdomain (%s) didn't enter target state %d\n",
  74                                 pwrst->pwrdm->name, pwrst->next_state);
  75                         ret = -1;
  76                 }
  77                 omap_set_pwrdm_state(pwrst->pwrdm, pwrst->saved_state);
  78                 pwrdm_set_logic_retst(pwrst->pwrdm, pwrst->saved_logic_state);
  79         }
  80         if (ret) {
  81                 pr_crit("Could not enter target state in pm_suspend\n");
  82                 /*
  83                  * OMAP4 chip PM currently works only with certain (newer)
  84                  * versions of bootloaders. This is due to missing code in the
  85                  * kernel to properly reset and initialize some devices.
  86                  * Warn the user about the bootloader version being one of the
  87                  * possible causes.
  88                  * http://www.spinics.net/lists/arm-kernel/msg218641.html
  89                  */
  90                 pr_warn("A possible cause could be an old bootloader - try u-boot >= v2012.07\n");
  91         } else {
  92                 pr_info("Successfully put all powerdomains to target state\n");
  93         }
  94
  95         return 0;
  96 }
  97 #endif /* CONFIG_SUSPEND */
  98
  99 static int __init pwrdms_setup(struct powerdomain *pwrdm, void *unused)
 100 {
 101         struct power_state *pwrst;
 102
 103         if (!pwrdm->pwrsts)
 104                 return 0;
 105
 106         /*
 107          * Skip CPU0 and CPU1 power domains. CPU1 is programmed
 108          * through hotplug path and CPU0 explicitly programmed
 109          * further down in the code path
 110          */
 111         if (!strncmp(pwrdm->name, "cpu", 3))
 112                 return 0;
 113
 114         pwrst = kmalloc(sizeof(struct power_state), GFP_ATOMIC);
 115         if (!pwrst)
 116                 return -ENOMEM;
 117
 118         pwrst->pwrdm = pwrdm;
 119         pwrst->next_state = PWRDM_POWER_RET;
 120         list_add(&pwrst->node, &pwrst_list);
 121
 122         return omap_set_pwrdm_state(pwrst->pwrdm, pwrst->next_state);
 123 }
 124
 125 /**
 126  * omap_default_idle - OMAP4 default ilde routine.'
 127  *
 128  * Implements OMAP4 memory, IO ordering requirements which can't be addressed
 129  * with default cpu_do_idle() hook. Used by all CPUs with !CONFIG_CPU_IDLE and
 130  * by secondary CPU with CONFIG_CPU_IDLE.
 131  */
 132 static void omap_default_idle(void)
 133 {
 134         omap_do_wfi();
 135 }
 136
 137 /**
 138  * omap4_pm_init - Init routine for OMAP4 PM
 139  *
 140  * Initializes all powerdomain and clockdomain target states
 141  * and all PRCM settings.
 142  */
 143 int __init omap4_pm_init(void)
 144 {
 145         int ret;
 146         struct clockdomain *emif_clkdm, *mpuss_clkdm, *l3_1_clkdm;
 147         struct clockdomain *ducati_clkdm, *l3_2_clkdm;
 148
 149         if (omap_rev() == OMAP4430_REV_ES1_0) {
 150                 WARN(1, "Power Management not supported on OMAP4430 ES1.0\n");
 151                 return -ENODEV;
 152         }
 153
 154         pr_err("Power Management for TI OMAP4.\n");
 155         /*
 156          * OMAP4 chip PM currently works only with certain (newer)
 157          * versions of bootloaders. This is due to missing code in the
 158          * kernel to properly reset and initialize some devices.
 159          * http://www.spinics.net/lists/arm-kernel/msg218641.html
 160          */
 161         pr_warn("OMAP4 PM: u-boot >= v2012.07 is required for full PM support\n");
 162
 163         ret = pwrdm_for_each(pwrdms_setup, NULL);
 164         if (ret) {
 165                 pr_err("Failed to setup powerdomains\n");
 166                 goto err2;
 167         }
 168
 169         /*
 170          * The dynamic dependency between MPUSS -> MEMIF and
 171          * MPUSS -> L4_PER/L3_* and DUCATI -> L3_* doesn't work as
 172          * expected. The hardware recommendation is to enable static
 173          * dependencies for these to avoid system lock ups or random crashes.
 174          */
 175         mpuss_clkdm = clkdm_lookup("mpuss_clkdm");
 176         emif_clkdm = clkdm_lookup("l3_emif_clkdm");
 177         l3_1_clkdm = clkdm_lookup("l3_1_clkdm");
 178         l3_2_clkdm = clkdm_lookup("l3_2_clkdm");
 179         ducati_clkdm = clkdm_lookup("ducati_clkdm");
 180         if ((!mpuss_clkdm) || (!emif_clkdm) || (!l3_1_clkdm) ||
 181                 (!l3_2_clkdm) || (!ducati_clkdm))
 182                 goto err2;
 183
 184         ret = clkdm_add_wkdep(mpuss_clkdm, emif_clkdm);
 185         ret |= clkdm_add_wkdep(mpuss_clkdm, l3_1_clkdm);
 186         ret |= clkdm_add_wkdep(mpuss_clkdm, l3_2_clkdm);
 187         ret |= clkdm_add_wkdep(ducati_clkdm, l3_1_clkdm);
 188         ret |= clkdm_add_wkdep(ducati_clkdm, l3_2_clkdm);
 189         if (ret) {
 190                 pr_err("Failed to add MPUSS -> L3/EMIF/L4PER, DUCATI -> L3 wakeup dependency\n");
 191                 goto err2;
 192         }
 193
 194         ret = omap4_mpuss_init();
 195         if (ret) {
 196                 pr_err("Failed to initialise OMAP4 MPUSS\n");
 197                 goto err2;
 198         }
 199
 200         (void) clkdm_for_each(omap_pm_clkdms_setup, NULL);
 201
 202 #ifdef CONFIG_SUSPEND
 203         omap_pm_suspend = omap4_pm_suspend;
 204 #endif
 205
 206         /* Overwrite the default cpu_do_idle() */
 207         arm_pm_idle = omap_default_idle;
 208
 209         omap4_idle_init();
 210
 211 err2:
 212         return ret;
 213 }