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 <linux/export.h>
  16 #include <asm/cacheflush.h>
  17 #include <asm/system_misc.h>
  18 #include <asm/tlbflush.h>
  19
  20 #include "common.h"
  21 #include "cpuidle.h"
  22 #include "crm-regs-imx5.h"
  23 #include "hardware.h"
  24
  25 /*
  26  * The WAIT_UNCLOCKED_POWER_OFF state only requires <= 500ns to exit.
  27  * This is also the lowest power state possible without affecting
  28  * non-cpu parts of the system.  For these reasons, imx5 should default
  29  * to always using this state for cpu idling.  The PM_SUSPEND_STANDBY also
  30  * uses this state and needs to take no action when registers remain confgiured
  31  * for this state.
  32  */
  33 #define IMX5_DEFAULT_CPU_IDLE_STATE WAIT_UNCLOCKED_POWER_OFF
  34
  35 /*
  36  * set cpu low power mode before WFI instruction. This function is called
  37  * mx5 because it can be used for mx51, and mx53.
  38  */
  39 static void mx5_cpu_lp_set(enum mxc_cpu_pwr_mode mode)
  40 {
  41         u32 plat_lpc, arm_srpgcr, ccm_clpcr;
  42         u32 empgc0, empgc1;
  43         int stop_mode = 0;
  44
  45         /* always allow platform to issue a deep sleep mode request */
  46         plat_lpc = __raw_readl(MXC_CORTEXA8_PLAT_LPC) &
  47             ~(MXC_CORTEXA8_PLAT_LPC_DSM);
  48         ccm_clpcr = __raw_readl(MXC_CCM_CLPCR) & ~(MXC_CCM_CLPCR_LPM_MASK);
  49         arm_srpgcr = __raw_readl(MXC_SRPG_ARM_SRPGCR) & ~(MXC_SRPGCR_PCR);
  50         empgc0 = __raw_readl(MXC_SRPG_EMPGC0_SRPGCR) & ~(MXC_SRPGCR_PCR);
  51         empgc1 = __raw_readl(MXC_SRPG_EMPGC1_SRPGCR) & ~(MXC_SRPGCR_PCR);
  52
  53         switch (mode) {
  54         case WAIT_CLOCKED:
  55                 break;
  56         case WAIT_UNCLOCKED:
  57                 ccm_clpcr |= 0x1 << MXC_CCM_CLPCR_LPM_OFFSET;
  58                 break;
  59         case WAIT_UNCLOCKED_POWER_OFF:
  60         case STOP_POWER_OFF:
  61                 plat_lpc |= MXC_CORTEXA8_PLAT_LPC_DSM
  62                             | MXC_CORTEXA8_PLAT_LPC_DBG_DSM;
  63                 if (mode == WAIT_UNCLOCKED_POWER_OFF) {
  64                         ccm_clpcr |= 0x1 << MXC_CCM_CLPCR_LPM_OFFSET;
  65                         ccm_clpcr &= ~MXC_CCM_CLPCR_VSTBY;
  66                         ccm_clpcr &= ~MXC_CCM_CLPCR_SBYOS;
  67                         stop_mode = 0;
  68                 } else {
  69                         ccm_clpcr |= 0x2 << MXC_CCM_CLPCR_LPM_OFFSET;
  70                         ccm_clpcr |= 0x3 << MXC_CCM_CLPCR_STBY_COUNT_OFFSET;
  71                         ccm_clpcr |= MXC_CCM_CLPCR_VSTBY;
  72                         ccm_clpcr |= MXC_CCM_CLPCR_SBYOS;
  73                         stop_mode = 1;
  74                 }
  75                 arm_srpgcr |= MXC_SRPGCR_PCR;
  76                 break;
  77         case STOP_POWER_ON:
  78                 ccm_clpcr |= 0x2 << MXC_CCM_CLPCR_LPM_OFFSET;
  79                 break;
  80         default:
  81                 printk(KERN_WARNING "UNKNOWN cpu power mode: %d\n", mode);
  82                 return;
  83         }
  84
  85         __raw_writel(plat_lpc, MXC_CORTEXA8_PLAT_LPC);
  86         __raw_writel(ccm_clpcr, MXC_CCM_CLPCR);
  87         __raw_writel(arm_srpgcr, MXC_SRPG_ARM_SRPGCR);
  88         __raw_writel(arm_srpgcr, MXC_SRPG_NEON_SRPGCR);
  89
  90         if (stop_mode) {
  91                 empgc0 |= MXC_SRPGCR_PCR;
  92                 empgc1 |= MXC_SRPGCR_PCR;
  93
  94                 __raw_writel(empgc0, MXC_SRPG_EMPGC0_SRPGCR);
  95                 __raw_writel(empgc1, MXC_SRPG_EMPGC1_SRPGCR);
  96         }
  97 }
  98
  99 static int mx5_suspend_enter(suspend_state_t state)
 100 {
 101         switch (state) {
 102         case PM_SUSPEND_MEM:
 103                 mx5_cpu_lp_set(STOP_POWER_OFF);
 104                 break;
 105         case PM_SUSPEND_STANDBY:
 106                 /* DEFAULT_IDLE_STATE already configured */
 107                 break;
 108         default:
 109                 return -EINVAL;
 110         }
 111
 112         if (state == PM_SUSPEND_MEM) {
 113                 local_flush_tlb_all();
 114                 flush_cache_all();
 115
 116                 /*clear the EMPGC0/1 bits */
 117                 __raw_writel(0, MXC_SRPG_EMPGC0_SRPGCR);
 118                 __raw_writel(0, MXC_SRPG_EMPGC1_SRPGCR);
 119         }
 120         cpu_do_idle();
 121
 122         /* return registers to default idle state */
 123         mx5_cpu_lp_set(IMX5_DEFAULT_CPU_IDLE_STATE);
 124         return 0;
 125 }
 126
 127 static int mx5_pm_valid(suspend_state_t state)
 128 {
 129         return (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX);
 130 }
 131
 132 static const struct platform_suspend_ops mx5_suspend_ops = {
 133         .valid = mx5_pm_valid,
 134         .enter = mx5_suspend_enter,
 135 };
 136
 137 static inline int imx5_cpu_do_idle(void)
 138 {
 139         int ret = tzic_enable_wake();
 140
 141         if (likely(!ret))
 142                 cpu_do_idle();
 143
 144         return ret;
 145 }
 146
 147 static void imx5_pm_idle(void)
 148 {
 149         imx5_cpu_do_idle();
 150 }
 151
 152 static int __init imx5_pm_common_init(void)
 153 {
 154         int ret;
 155         struct clk *gpc_dvfs_clk = clk_get(NULL, "gpc_dvfs");
 156
 157         if (IS_ERR(gpc_dvfs_clk))
 158                 return PTR_ERR(gpc_dvfs_clk);
 159
 160         ret = clk_prepare_enable(gpc_dvfs_clk);
 161         if (ret)
 162                 return ret;
 163
 164         arm_pm_idle = imx5_pm_idle;
 165
 166         /* Set the registers to the default cpu idle state. */
 167         mx5_cpu_lp_set(IMX5_DEFAULT_CPU_IDLE_STATE);
 168
 169         return imx5_cpuidle_init();
 170 }
 171
 172 void __init imx5_pm_init(void)
 173 {
 174         int ret = imx5_pm_common_init();
 175         if (!ret)
 176                 suspend_set_ops(&mx5_suspend_ops);
 177 }