arch/arm/mach-davinci/pm.c

   1 /*
   2  * DaVinci Power Management Routines
   3  *
   4  * Copyright (C) 2009 Texas Instruments, Inc. http://www.ti.com/
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  */
  10
  11 #include <linux/pm.h>
  12 #include <linux/suspend.h>
  13 #include <linux/module.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/clk.h>
  16 #include <linux/spinlock.h>
  17
  18 #include <asm/cacheflush.h>
  19 #include <asm/delay.h>
  20
  21 #include <mach/da8xx.h>
  22 #include <mach/sram.h>
  23 #include <mach/pm.h>
  24
  25 #include "clock.h"
  26
  27 #define DEEPSLEEP_SLEEPCOUNT_MASK       0xFFFF
  28
  29 static void (*davinci_sram_suspend) (struct davinci_pm_config *);
  30 static struct davinci_pm_config *pdata;
  31
  32 static void davinci_sram_push(void *dest, void *src, unsigned int size)
  33 {
  34         memcpy(dest, src, size);
  35         flush_icache_range((unsigned long)dest, (unsigned long)(dest + size));
  36 }
  37
  38 static void davinci_pm_suspend(void)
  39 {
  40         unsigned val;
  41
  42         if (pdata->cpupll_reg_base != pdata->ddrpll_reg_base) {
  43
  44                 /* Switch CPU PLL to bypass mode */
  45                 val = __raw_readl(pdata->cpupll_reg_base + PLLCTL);
  46                 val &= ~(PLLCTL_PLLENSRC | PLLCTL_PLLEN);
  47                 __raw_writel(val, pdata->cpupll_reg_base + PLLCTL);
  48
  49                 udelay(PLL_BYPASS_TIME);
  50
  51                 /* Powerdown CPU PLL */
  52                 val = __raw_readl(pdata->cpupll_reg_base + PLLCTL);
  53                 val |= PLLCTL_PLLPWRDN;
  54                 __raw_writel(val, pdata->cpupll_reg_base + PLLCTL);
  55         }
  56
  57         /* Configure sleep count in deep sleep register */
  58         val = __raw_readl(pdata->deepsleep_reg);
  59         val &= ~DEEPSLEEP_SLEEPCOUNT_MASK,
  60         val |= pdata->sleepcount;
  61         __raw_writel(val, pdata->deepsleep_reg);
  62
  63         /* System goes to sleep in this call */
  64         davinci_sram_suspend(pdata);
  65
  66         if (pdata->cpupll_reg_base != pdata->ddrpll_reg_base) {
  67
  68                 /* put CPU PLL in reset */
  69                 val = __raw_readl(pdata->cpupll_reg_base + PLLCTL);
  70                 val &= ~PLLCTL_PLLRST;
  71                 __raw_writel(val, pdata->cpupll_reg_base + PLLCTL);
  72
  73                 /* put CPU PLL in power down */
  74                 val = __raw_readl(pdata->cpupll_reg_base + PLLCTL);
  75                 val &= ~PLLCTL_PLLPWRDN;
  76                 __raw_writel(val, pdata->cpupll_reg_base + PLLCTL);
  77
  78                 /* wait for CPU PLL reset */
  79                 udelay(PLL_RESET_TIME);
  80
  81                 /* bring CPU PLL out of reset */
  82                 val = __raw_readl(pdata->cpupll_reg_base + PLLCTL);
  83                 val |= PLLCTL_PLLRST;
  84                 __raw_writel(val, pdata->cpupll_reg_base + PLLCTL);
  85
  86                 /* Wait for CPU PLL to lock */
  87                 udelay(PLL_LOCK_TIME);
  88
  89                 /* Remove CPU PLL from bypass mode */
  90                 val = __raw_readl(pdata->cpupll_reg_base + PLLCTL);
  91                 val &= ~PLLCTL_PLLENSRC;
  92                 val |= PLLCTL_PLLEN;
  93                 __raw_writel(val, pdata->cpupll_reg_base + PLLCTL);
  94         }
  95 }
  96
  97 static int davinci_pm_enter(suspend_state_t state)
  98 {
  99         int ret = 0;
 100
 101         switch (state) {
 102         case PM_SUSPEND_STANDBY:
 103         case PM_SUSPEND_MEM:
 104                 davinci_pm_suspend();
 105                 break;
 106         default:
 107                 ret = -EINVAL;
 108         }
 109
 110         return ret;
 111 }
 112
 113 static const struct platform_suspend_ops davinci_pm_ops = {
 114         .enter          = davinci_pm_enter,
 115         .valid          = suspend_valid_only_mem,
 116 };
 117
 118 static int __init davinci_pm_probe(struct platform_device *pdev)
 119 {
 120         pdata = pdev->dev.platform_data;
 121         if (!pdata) {
 122                 dev_err(&pdev->dev, "cannot get platform data\n");
 123                 return -ENOENT;
 124         }
 125
 126         davinci_sram_suspend = sram_alloc(davinci_cpu_suspend_sz, NULL);
 127         if (!davinci_sram_suspend) {
 128                 dev_err(&pdev->dev, "cannot allocate SRAM memory\n");
 129                 return -ENOMEM;
 130         }
 131
 132         davinci_sram_push(davinci_sram_suspend, davinci_cpu_suspend,
 133                                                 davinci_cpu_suspend_sz);
 134
 135         suspend_set_ops(&davinci_pm_ops);
 136
 137         return 0;
 138 }
 139
 140 static int __exit davinci_pm_remove(struct platform_device *pdev)
 141 {
 142         sram_free(davinci_sram_suspend, davinci_cpu_suspend_sz);
 143         return 0;
 144 }
 145
 146 static struct platform_driver davinci_pm_driver = {
 147         .driver = {
 148                 .name    = "pm-davinci",
 149                 .owner   = THIS_MODULE,
 150         },
 151         .remove = __exit_p(davinci_pm_remove),
 152 };
 153
 154 static int __init davinci_pm_init(void)
 155 {
 156         return platform_driver_probe(&davinci_pm_driver, davinci_pm_probe);
 157 }
 158 late_initcall(davinci_pm_init);