arch/arm/mach-imx/pm-imx5.c

   1 /*
   2  *  Copyright (C) 2011 Freescale Semiconductor, Inc. All Rights Reserved.
   3  *
   4  * The code contained herein is licensed under the GNU General Public
   5  * License. You may obtain a copy of the GNU General Public License
   6  * Version 2 or later at the following locations:
   7  *
   8  * http://www.opensource.org/licenses/gpl-license.html
   9  * http://www.gnu.org/copyleft/gpl.html
  10  */
  11 #include <linux/suspend.h>
  12 #include <linux/clk.h>
  13 #include <linux/io.h>
  14 #include <linux/err.h>
  15 #include <asm/cacheflush.h>
  16 #include <asm/tlbflush.h>
  17 #include <mach/common.h>
  18 #include <mach/hardware.h>
  19 #include "crm-regs-imx5.h"
  20
  21 static struct clk *gpc_dvfs_clk;
  22
  23 /*
  24  * set cpu low power mode before WFI instruction. This function is called
  25  * mx5 because it can be used for mx50, mx51, and mx53.
  26  */
  27 void mx5_cpu_lp_set(enum mxc_cpu_pwr_mode mode)
  28 {
  29         u32 plat_lpc, arm_srpgcr, ccm_clpcr;
  30         u32 empgc0, empgc1;
  31         int stop_mode = 0;
  32
  33         /* always allow platform to issue a deep sleep mode request */
  34         plat_lpc = __raw_readl(MXC_CORTEXA8_PLAT_LPC) &
  35             ~(MXC_CORTEXA8_PLAT_LPC_DSM);
  36         ccm_clpcr = __raw_readl(MXC_CCM_CLPCR) & ~(MXC_CCM_CLPCR_LPM_MASK);
  37         arm_srpgcr = __raw_readl(MXC_SRPG_ARM_SRPGCR) & ~(MXC_SRPGCR_PCR);
  38         empgc0 = __raw_readl(MXC_SRPG_EMPGC0_SRPGCR) & ~(MXC_SRPGCR_PCR);
  39         empgc1 = __raw_readl(MXC_SRPG_EMPGC1_SRPGCR) & ~(MXC_SRPGCR_PCR);
  40
  41         switch (mode) {
  42         case WAIT_CLOCKED:
  43                 break;
  44         case WAIT_UNCLOCKED:
  45                 ccm_clpcr |= 0x1 << MXC_CCM_CLPCR_LPM_OFFSET;
  46                 break;
  47         case WAIT_UNCLOCKED_POWER_OFF:
  48         case STOP_POWER_OFF:
  49                 plat_lpc |= MXC_CORTEXA8_PLAT_LPC_DSM
  50                             | MXC_CORTEXA8_PLAT_LPC_DBG_DSM;
  51                 if (mode == WAIT_UNCLOCKED_POWER_OFF) {
  52                         ccm_clpcr |= 0x1 << MXC_CCM_CLPCR_LPM_OFFSET;
  53                         ccm_clpcr &= ~MXC_CCM_CLPCR_VSTBY;
  54                         ccm_clpcr &= ~MXC_CCM_CLPCR_SBYOS;
  55                         stop_mode = 0;
  56                 } else {
  57                         ccm_clpcr |= 0x2 << MXC_CCM_CLPCR_LPM_OFFSET;
  58                         ccm_clpcr |= 0x3 << MXC_CCM_CLPCR_STBY_COUNT_OFFSET;
  59                         ccm_clpcr |= MXC_CCM_CLPCR_VSTBY;
  60                         ccm_clpcr |= MXC_CCM_CLPCR_SBYOS;
  61                         stop_mode = 1;
  62                 }
  63                 arm_srpgcr |= MXC_SRPGCR_PCR;
  64                 break;
  65         case STOP_POWER_ON:
  66                 ccm_clpcr |= 0x2 << MXC_CCM_CLPCR_LPM_OFFSET;
  67                 break;
  68         default:
  69                 printk(KERN_WARNING "UNKNOWN cpu power mode: %d\n", mode);
  70                 return;
  71         }
  72
  73         __raw_writel(plat_lpc, MXC_CORTEXA8_PLAT_LPC);
  74         __raw_writel(ccm_clpcr, MXC_CCM_CLPCR);
  75         __raw_writel(arm_srpgcr, MXC_SRPG_ARM_SRPGCR);
  76
  77         /* Enable NEON SRPG for all but MX50TO1.0. */
  78         if (mx50_revision() != IMX_CHIP_REVISION_1_0)
  79                 __raw_writel(arm_srpgcr, MXC_SRPG_NEON_SRPGCR);
  80
  81         if (stop_mode) {
  82                 empgc0 |= MXC_SRPGCR_PCR;
  83                 empgc1 |= MXC_SRPGCR_PCR;
  84
  85                 __raw_writel(empgc0, MXC_SRPG_EMPGC0_SRPGCR);
  86                 __raw_writel(empgc1, MXC_SRPG_EMPGC1_SRPGCR);
  87         }
  88 }
  89
  90 static int mx5_suspend_prepare(void)
  91 {
  92         return clk_enable(gpc_dvfs_clk);
  93 }
  94
  95 static int mx5_suspend_enter(suspend_state_t state)
  96 {
  97         switch (state) {
  98         case PM_SUSPEND_MEM:
  99                 mx5_cpu_lp_set(STOP_POWER_OFF);
 100                 break;
 101         case PM_SUSPEND_STANDBY:
 102                 mx5_cpu_lp_set(WAIT_UNCLOCKED_POWER_OFF);
 103                 break;
 104         default:
 105                 return -EINVAL;
 106         }
 107
 108         if (state == PM_SUSPEND_MEM) {
 109                 local_flush_tlb_all();
 110                 flush_cache_all();
 111
 112                 /*clear the EMPGC0/1 bits */
 113                 __raw_writel(0, MXC_SRPG_EMPGC0_SRPGCR);
 114                 __raw_writel(0, MXC_SRPG_EMPGC1_SRPGCR);
 115         }
 116         cpu_do_idle();
 117         return 0;
 118 }
 119
 120 static void mx5_suspend_finish(void)
 121 {
 122         clk_disable(gpc_dvfs_clk);
 123 }
 124
 125 static int mx5_pm_valid(suspend_state_t state)
 126 {
 127         return (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX);
 128 }
 129
 130 static const struct platform_suspend_ops mx5_suspend_ops = {
 131         .valid = mx5_pm_valid,
 132         .prepare = mx5_suspend_prepare,
 133         .enter = mx5_suspend_enter,
 134         .finish = mx5_suspend_finish,
 135 };
 136
 137 static int __init mx5_pm_init(void)
 138 {
 139         if (!cpu_is_mx51() && !cpu_is_mx53())
 140                 return 0;
 141
 142         if (gpc_dvfs_clk == NULL)
 143                 gpc_dvfs_clk = clk_get(NULL, "gpc_dvfs");
 144
 145         if (!IS_ERR(gpc_dvfs_clk)) {
 146                 if (cpu_is_mx51())
 147                         suspend_set_ops(&mx5_suspend_ops);
 148         } else
 149                 return -EPERM;
 150
 151         return 0;
 152 }
 153 device_initcall(mx5_pm_init);