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 #include <mach/common.h>
  20 #include <mach/cpuidle.h>
  21 #include <mach/hardware.h>
  22 #include "crm-regs-imx5.h"
  23
  24 /*
  25  * The WAIT_UNCLOCKED_POWER_OFF state only requires <= 500ns to exit.
  26  * This is also the lowest power state possible without affecting
  27  * non-cpu parts of the system.  For these reasons, imx5 should default
  28  * to always using this state for cpu idling.  The PM_SUSPEND_STANDBY also
  29  * uses this state and needs to take no action when registers remain confgiured
  30  * for this state.
  31  */
  32 #define IMX5_DEFAULT_CPU_IDLE_STATE WAIT_UNCLOCKED_POWER_OFF
  33
  34 /*
  35  * set cpu low power mode before WFI instruction. This function is called
  36  * mx5 because it can be used for mx50, mx51, and mx53.
  37  */
  38 static void mx5_cpu_lp_set(enum mxc_cpu_pwr_mode mode)
  39 {
  40         u32 plat_lpc, arm_srpgcr, ccm_clpcr;
  41         u32 empgc0, empgc1;
  42         int stop_mode = 0;
  43
  44         /* always allow platform to issue a deep sleep mode request */
  45         plat_lpc = __raw_readl(MXC_CORTEXA8_PLAT_LPC) &
  46             ~(MXC_CORTEXA8_PLAT_LPC_DSM);
  47         ccm_clpcr = __raw_readl(MXC_CCM_CLPCR) & ~(MXC_CCM_CLPCR_LPM_MASK);
  48         arm_srpgcr = __raw_readl(MXC_SRPG_ARM_SRPGCR) & ~(MXC_SRPGCR_PCR);
  49         empgc0 = __raw_readl(MXC_SRPG_EMPGC0_SRPGCR) & ~(MXC_SRPGCR_PCR);
  50         empgc1 = __raw_readl(MXC_SRPG_EMPGC1_SRPGCR) & ~(MXC_SRPGCR_PCR);
  51
  52         switch (mode) {
  53         case WAIT_CLOCKED:
  54                 break;
  55         case WAIT_UNCLOCKED:
  56                 ccm_clpcr |= 0x1 << MXC_CCM_CLPCR_LPM_OFFSET;
  57                 break;
  58         case WAIT_UNCLOCKED_POWER_OFF:
  59         case STOP_POWER_OFF:
  60                 plat_lpc |= MXC_CORTEXA8_PLAT_LPC_DSM
  61                             | MXC_CORTEXA8_PLAT_LPC_DBG_DSM;
  62                 if (mode == WAIT_UNCLOCKED_POWER_OFF) {
  63                         ccm_clpcr |= 0x1 << MXC_CCM_CLPCR_LPM_OFFSET;
  64                         ccm_clpcr &= ~MXC_CCM_CLPCR_VSTBY;
  65                         ccm_clpcr &= ~MXC_CCM_CLPCR_SBYOS;
  66                         stop_mode = 0;
  67                 } else {
  68                         ccm_clpcr |= 0x2 << MXC_CCM_CLPCR_LPM_OFFSET;
  69                         ccm_clpcr |= 0x3 << MXC_CCM_CLPCR_STBY_COUNT_OFFSET;
  70                         ccm_clpcr |= MXC_CCM_CLPCR_VSTBY;
  71                         ccm_clpcr |= MXC_CCM_CLPCR_SBYOS;
  72                         stop_mode = 1;
  73                 }
  74                 arm_srpgcr |= MXC_SRPGCR_PCR;
  75                 break;
  76         case STOP_POWER_ON:
  77                 ccm_clpcr |= 0x2 << MXC_CCM_CLPCR_LPM_OFFSET;
  78                 break;
  79         default:
  80                 printk(KERN_WARNING "UNKNOWN cpu power mode: %d\n", mode);
  81                 return;
  82         }
  83
  84         __raw_writel(plat_lpc, MXC_CORTEXA8_PLAT_LPC);
  85         __raw_writel(ccm_clpcr, MXC_CCM_CLPCR);
  86         __raw_writel(arm_srpgcr, MXC_SRPG_ARM_SRPGCR);
  87
  88         /* Enable NEON SRPG for all but MX50TO1.0. */
  89         if (mx50_revision() != IMX_CHIP_REVISION_1_0)
  90                 __raw_writel(arm_srpgcr, MXC_SRPG_NEON_SRPGCR);
  91
  92         if (stop_mode) {
  93                 empgc0 |= MXC_SRPGCR_PCR;
  94                 empgc1 |= MXC_SRPGCR_PCR;
  95
  96                 __raw_writel(empgc0, MXC_SRPG_EMPGC0_SRPGCR);
  97                 __raw_writel(empgc1, MXC_SRPG_EMPGC1_SRPGCR);
  98         }
  99 }
 100
 101 static int mx5_suspend_enter(suspend_state_t state)
 102 {
 103         switch (state) {
 104         case PM_SUSPEND_MEM:
 105                 mx5_cpu_lp_set(STOP_POWER_OFF);
 106                 break;
 107         case PM_SUSPEND_STANDBY:
 108                 /* DEFAULT_IDLE_STATE already configured */
 109                 break;
 110         default:
 111                 return -EINVAL;
 112         }
 113
 114         if (state == PM_SUSPEND_MEM) {
 115                 local_flush_tlb_all();
 116                 flush_cache_all();
 117
 118                 /*clear the EMPGC0/1 bits */
 119                 __raw_writel(0, MXC_SRPG_EMPGC0_SRPGCR);
 120                 __raw_writel(0, MXC_SRPG_EMPGC1_SRPGCR);
 121         }
 122         cpu_do_idle();
 123
 124         /* return registers to default idle state */
 125         mx5_cpu_lp_set(IMX5_DEFAULT_CPU_IDLE_STATE);
 126         return 0;
 127 }
 128
 129 static int mx5_pm_valid(suspend_state_t state)
 130 {
 131         return (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX);
 132 }
 133
 134 static const struct platform_suspend_ops mx5_suspend_ops = {
 135         .valid = mx5_pm_valid,
 136         .enter = mx5_suspend_enter,
 137 };
 138
 139 static inline int imx5_cpu_do_idle(void)
 140 {
 141         int ret = tzic_enable_wake();
 142
 143         if (likely(!ret))
 144                 cpu_do_idle();
 145
 146         return ret;
 147 }
 148
 149 static void imx5_pm_idle(void)
 150 {
 151         imx5_cpu_do_idle();
 152 }
 153
 154 static int imx5_cpuidle_enter(struct cpuidle_device *dev,
 155                                 struct cpuidle_driver *drv, int idx)
 156 {
 157         int ret;
 158
 159         ret = imx5_cpu_do_idle();
 160         if (ret < 0)
 161                 return ret;
 162
 163         return idx;
 164 }
 165
 166 static struct cpuidle_driver imx5_cpuidle_driver = {
 167         .name                   = "imx5_cpuidle",
 168         .owner                  = THIS_MODULE,
 169         .en_core_tk_irqen       = 1,
 170         .states[0]      = {
 171                 .enter                  = imx5_cpuidle_enter,
 172                 .exit_latency           = 2,
 173                 .target_residency       = 1,
 174                 .flags                  = CPUIDLE_FLAG_TIME_VALID,
 175                 .name                   = "IMX5 SRPG",
 176                 .desc                   = "CPU state retained,powered off",
 177         },
 178         .state_count            = 1,
 179 };
 180
 181 static int __init imx5_pm_common_init(void)
 182 {
 183         int ret;
 184         struct clk *gpc_dvfs_clk = clk_get(NULL, "gpc_dvfs");
 185
 186         if (IS_ERR(gpc_dvfs_clk))
 187                 return PTR_ERR(gpc_dvfs_clk);
 188
 189         ret = clk_prepare_enable(gpc_dvfs_clk);
 190         if (ret)
 191                 return ret;
 192
 193         arm_pm_idle = imx5_pm_idle;
 194
 195         /* Set the registers to the default cpu idle state. */
 196         mx5_cpu_lp_set(IMX5_DEFAULT_CPU_IDLE_STATE);
 197
 198         imx_cpuidle_init(&imx5_cpuidle_driver);
 199         return 0;
 200 }
 201
 202 void __init imx51_pm_init(void)
 203 {
 204         int ret = imx5_pm_common_init();
 205         if (!ret)
 206                 suspend_set_ops(&mx5_suspend_ops);
 207 }
 208
 209 void __init imx53_pm_init(void)
 210 {
 211         imx5_pm_common_init();
 212 }