arch/arm/mach-omap2/pm44xx.c

   1 /*
   2  * OMAP4+ Power Management Routines
   3  *
   4  * Copyright (C) 2010-2013 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 u16 pm44xx_errata;
  28
  29 struct power_state {
  30         struct powerdomain *pwrdm;
  31         u32 next_state;
  32 #ifdef CONFIG_SUSPEND
  33         u32 saved_state;
  34         u32 saved_logic_state;
  35 #endif
  36         struct list_head node;
  37 };
  38
  39 static LIST_HEAD(pwrst_list);
  40
  41 #ifdef CONFIG_SUSPEND
  42 static int omap4_pm_suspend(void)
  43 {
  44         struct power_state *pwrst;
  45         int state, ret = 0;
  46         u32 cpu_id = smp_processor_id();
  47
  48         /* Save current powerdomain state */
  49         list_for_each_entry(pwrst, &pwrst_list, node) {
  50                 pwrst->saved_state = pwrdm_read_next_pwrst(pwrst->pwrdm);
  51                 pwrst->saved_logic_state = pwrdm_read_logic_retst(pwrst->pwrdm);
  52         }
  53
  54         /* Set targeted power domain states by suspend */
  55         list_for_each_entry(pwrst, &pwrst_list, node) {
  56                 omap_set_pwrdm_state(pwrst->pwrdm, pwrst->next_state);
  57                 pwrdm_set_logic_retst(pwrst->pwrdm, PWRDM_POWER_OFF);
  58         }
  59
  60         /*
  61          * For MPUSS to hit power domain retention(CSWR or OSWR),
  62          * CPU0 and CPU1 power domains need to be in OFF or DORMANT state,
  63          * since CPU power domain CSWR is not supported by hardware
  64          * Only master CPU follows suspend path. All other CPUs follow
  65          * CPU hotplug path in system wide suspend. On OMAP4, CPU power
  66          * domain CSWR is not supported by hardware.
  67          * More details can be found in OMAP4430 TRM section 4.3.4.2.
  68          */
  69         omap4_enter_lowpower(cpu_id, PWRDM_POWER_OFF);
  70
  71         /* Restore next powerdomain state */
  72         list_for_each_entry(pwrst, &pwrst_list, node) {
  73                 state = pwrdm_read_prev_pwrst(pwrst->pwrdm);
  74                 if (state > pwrst->next_state) {
  75                         pr_info("Powerdomain (%s) didn't enter target state %d\n",
  76                                 pwrst->pwrdm->name, pwrst->next_state);
  77                         ret = -1;
  78                 }
  79                 omap_set_pwrdm_state(pwrst->pwrdm, pwrst->saved_state);
  80                 pwrdm_set_logic_retst(pwrst->pwrdm, pwrst->saved_logic_state);
  81         }
  82         if (ret) {
  83                 pr_crit("Could not enter target state in pm_suspend\n");
  84                 /*
  85                  * OMAP4 chip PM currently works only with certain (newer)
  86                  * versions of bootloaders. This is due to missing code in the
  87                  * kernel to properly reset and initialize some devices.
  88                  * Warn the user about the bootloader version being one of the
  89                  * possible causes.
  90                  * http://www.spinics.net/lists/arm-kernel/msg218641.html
  91                  */
  92                 pr_warn("A possible cause could be an old bootloader - try u-boot >= v2012.07\n");
  93         } else {
  94                 pr_info("Successfully put all powerdomains to target state\n");
  95         }
  96
  97         return 0;
  98 }
  99 #endif /* CONFIG_SUSPEND */
 100
 101 static int __init pwrdms_setup(struct powerdomain *pwrdm, void *unused)
 102 {
 103         struct power_state *pwrst;
 104
 105         if (!pwrdm->pwrsts)
 106                 return 0;
 107
 108         /*
 109          * Skip CPU0 and CPU1 power domains. CPU1 is programmed
 110          * through hotplug path and CPU0 explicitly programmed
 111          * further down in the code path
 112          */
 113         if (!strncmp(pwrdm->name, "cpu", 3))
 114                 return 0;
 115
 116         pwrst = kmalloc(sizeof(struct power_state), GFP_ATOMIC);
 117         if (!pwrst)
 118                 return -ENOMEM;
 119
 120         pwrst->pwrdm = pwrdm;
 121         pwrst->next_state = PWRDM_POWER_RET;
 122         list_add(&pwrst->node, &pwrst_list);
 123
 124         return omap_set_pwrdm_state(pwrst->pwrdm, pwrst->next_state);
 125 }
 126
 127 /**
 128  * omap_default_idle - OMAP4 default ilde routine.'
 129  *
 130  * Implements OMAP4 memory, IO ordering requirements which can't be addressed
 131  * with default cpu_do_idle() hook. Used by all CPUs with !CONFIG_CPU_IDLE and
 132  * by secondary CPU with CONFIG_CPU_IDLE.
 133  */
 134 static void omap_default_idle(void)
 135 {
 136         omap_do_wfi();
 137 }
 138
 139 /**
 140  * omap4_init_static_deps - Add OMAP4 static dependencies
 141  *
 142  * Add needed static clockdomain dependencies on OMAP4 devices.
 143  * Return: 0 on success or 'err' on failures
 144  */
 145 static inline int omap4_init_static_deps(void)
 146 {
 147         struct clockdomain *emif_clkdm, *mpuss_clkdm, *l3_1_clkdm;
 148         struct clockdomain *ducati_clkdm, *l3_2_clkdm;
 149         int ret = 0;
 150
 151         if (omap_rev() == OMAP4430_REV_ES1_0) {
 152                 WARN(1, "Power Management not supported on OMAP4430 ES1.0\n");
 153                 return -ENODEV;
 154         }
 155
 156         pr_err("Power Management for TI OMAP4.\n");
 157         /*
 158          * OMAP4 chip PM currently works only with certain (newer)
 159          * versions of bootloaders. This is due to missing code in the
 160          * kernel to properly reset and initialize some devices.
 161          * http://www.spinics.net/lists/arm-kernel/msg218641.html
 162          */
 163         pr_warn("OMAP4 PM: u-boot >= v2012.07 is required for full PM support\n");
 164
 165         ret = pwrdm_for_each(pwrdms_setup, NULL);
 166         if (ret) {
 167                 pr_err("Failed to setup powerdomains\n");
 168                 return ret;
 169         }
 170
 171         /*
 172          * The dynamic dependency between MPUSS -> MEMIF and
 173          * MPUSS -> L4_PER/L3_* and DUCATI -> L3_* doesn't work as
 174          * expected. The hardware recommendation is to enable static
 175          * dependencies for these to avoid system lock ups or random crashes.
 176          * The L4 wakeup depedency is added to workaround the OCP sync hardware
 177          * BUG with 32K synctimer which lead to incorrect timer value read
 178          * from the 32K counter. The BUG applies for GPTIMER1 and WDT2 which
 179          * are part of L4 wakeup clockdomain.
 180          */
 181         mpuss_clkdm = clkdm_lookup("mpuss_clkdm");
 182         emif_clkdm = clkdm_lookup("l3_emif_clkdm");
 183         l3_1_clkdm = clkdm_lookup("l3_1_clkdm");
 184         l3_2_clkdm = clkdm_lookup("l3_2_clkdm");
 185         ducati_clkdm = clkdm_lookup("ducati_clkdm");
 186         if ((!mpuss_clkdm) || (!emif_clkdm) || (!l3_1_clkdm) ||
 187                 (!l3_2_clkdm) || (!ducati_clkdm))
 188                 return -EINVAL;
 189
 190         ret = clkdm_add_wkdep(mpuss_clkdm, emif_clkdm);
 191         ret |= clkdm_add_wkdep(mpuss_clkdm, l3_1_clkdm);
 192         ret |= clkdm_add_wkdep(mpuss_clkdm, l3_2_clkdm);
 193         ret |= clkdm_add_wkdep(ducati_clkdm, l3_1_clkdm);
 194         ret |= clkdm_add_wkdep(ducati_clkdm, l3_2_clkdm);
 195         if (ret) {
 196                 pr_err("Failed to add MPUSS -> L3/EMIF/L4PER, DUCATI -> L3 wakeup dependency\n");
 197                 return -EINVAL;
 198         }
 199
 200         return ret;
 201 }
 202
 203 /**
 204  * omap4_pm_init_early - Does early initialization necessary for OMAP4+ devices
 205  *
 206  * Initializes basic stuff for power management functionality.
 207  */
 208 int __init omap4_pm_init_early(void)
 209 {
 210         if (cpu_is_omap446x())
 211                 pm44xx_errata |= PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD;
 212
 213         return 0;
 214 }
 215
 216 /**
 217  * omap4_pm_init - Init routine for OMAP4+ devices
 218  *
 219  * Initializes all powerdomain and clockdomain target states
 220  * and all PRCM settings.
 221  * Return: Returns the error code returned by called functions.
 222  */
 223 int __init omap4_pm_init(void)
 224 {
 225         int ret = 0;
 226
 227         if (omap_rev() == OMAP4430_REV_ES1_0) {
 228                 WARN(1, "Power Management not supported on OMAP4430 ES1.0\n");
 229                 return -ENODEV;
 230         }
 231
 232         pr_info("Power Management for TI OMAP4+ devices.\n");
 233
 234         ret = pwrdm_for_each(pwrdms_setup, NULL);
 235         if (ret) {
 236                 pr_err("Failed to setup powerdomains.\n");
 237                 goto err2;
 238         }
 239
 240         if (cpu_is_omap44xx()) {
 241                 ret = omap4_init_static_deps();
 242                 if (ret)
 243                         goto err2;
 244         }
 245
 246         ret = omap4_mpuss_init();
 247         if (ret) {
 248                 pr_err("Failed to initialise OMAP4 MPUSS\n");
 249                 goto err2;
 250         }
 251
 252         (void) clkdm_for_each(omap_pm_clkdms_setup, NULL);
 253
 254 #ifdef CONFIG_SUSPEND
 255         omap_pm_suspend = omap4_pm_suspend;
 256 #endif
 257
 258         /* Overwrite the default cpu_do_idle() */
 259         arm_pm_idle = omap_default_idle;
 260
 261         if (cpu_is_omap44xx())
 262                 omap4_idle_init();
 263
 264 err2:
 265         return ret;
 266 }