arch/arm/mach-mx5/system.c

   1 /*
   2  * Copyright (C) 2011 Freescale Semiconductor, Inc. All Rights Reserved.
   3  */
   4
   5 /*
   6  * The code contained herein is licensed under the GNU General Public
   7  * License. You may obtain a copy of the GNU General Public License
   8  * Version 2 or later at the following locations:
   9  *
  10  * http://www.opensource.org/licenses/gpl-license.html
  11  * http://www.gnu.org/copyleft/gpl.html
  12  */
  13 #include <linux/platform_device.h>
  14 #include <linux/io.h>
  15 #include <mach/hardware.h>
  16 #include <mach/common.h>
  17 #include "crm_regs.h"
  18
  19 /* set cpu low power mode before WFI instruction. This function is called
  20   * mx5 because it can be used for mx50, mx51, and mx53.*/
  21 void mx5_cpu_lp_set(enum mxc_cpu_pwr_mode mode)
  22 {
  23         u32 plat_lpc, arm_srpgcr, ccm_clpcr;
  24         u32 empgc0, empgc1;
  25         int stop_mode = 0;
  26
  27         /* always allow platform to issue a deep sleep mode request */
  28         plat_lpc = __raw_readl(MXC_CORTEXA8_PLAT_LPC) &
  29             ~(MXC_CORTEXA8_PLAT_LPC_DSM);
  30         ccm_clpcr = __raw_readl(MXC_CCM_CLPCR) & ~(MXC_CCM_CLPCR_LPM_MASK);
  31         arm_srpgcr = __raw_readl(MXC_SRPG_ARM_SRPGCR) & ~(MXC_SRPGCR_PCR);
  32         empgc0 = __raw_readl(MXC_SRPG_EMPGC0_SRPGCR) & ~(MXC_SRPGCR_PCR);
  33         empgc1 = __raw_readl(MXC_SRPG_EMPGC1_SRPGCR) & ~(MXC_SRPGCR_PCR);
  34
  35         switch (mode) {
  36         case WAIT_CLOCKED:
  37                 break;
  38         case WAIT_UNCLOCKED:
  39                 ccm_clpcr |= 0x1 << MXC_CCM_CLPCR_LPM_OFFSET;
  40                 break;
  41         case WAIT_UNCLOCKED_POWER_OFF:
  42         case STOP_POWER_OFF:
  43                 plat_lpc |= MXC_CORTEXA8_PLAT_LPC_DSM
  44                             | MXC_CORTEXA8_PLAT_LPC_DBG_DSM;
  45                 if (mode == WAIT_UNCLOCKED_POWER_OFF) {
  46                         ccm_clpcr |= 0x1 << MXC_CCM_CLPCR_LPM_OFFSET;
  47                         ccm_clpcr &= ~MXC_CCM_CLPCR_VSTBY;
  48                         ccm_clpcr &= ~MXC_CCM_CLPCR_SBYOS;
  49                         stop_mode = 0;
  50                 } else {
  51                         ccm_clpcr |= 0x2 << MXC_CCM_CLPCR_LPM_OFFSET;
  52                         ccm_clpcr |= 0x3 << MXC_CCM_CLPCR_STBY_COUNT_OFFSET;
  53                         ccm_clpcr |= MXC_CCM_CLPCR_VSTBY;
  54                         ccm_clpcr |= MXC_CCM_CLPCR_SBYOS;
  55                         stop_mode = 1;
  56                 }
  57                 arm_srpgcr |= MXC_SRPGCR_PCR;
  58
  59                 if (tzic_enable_wake(1) != 0)
  60                         return;
  61                 break;
  62         case STOP_POWER_ON:
  63                 ccm_clpcr |= 0x2 << MXC_CCM_CLPCR_LPM_OFFSET;
  64                 break;
  65         default:
  66                 printk(KERN_WARNING "UNKNOWN cpu power mode: %d\n", mode);
  67                 return;
  68         }
  69
  70         __raw_writel(plat_lpc, MXC_CORTEXA8_PLAT_LPC);
  71         __raw_writel(ccm_clpcr, MXC_CCM_CLPCR);
  72         __raw_writel(arm_srpgcr, MXC_SRPG_ARM_SRPGCR);
  73
  74         /* Enable NEON SRPG for all but MX50TO1.0. */
  75         if (mx50_revision() != IMX_CHIP_REVISION_1_0)
  76                 __raw_writel(arm_srpgcr, MXC_SRPG_NEON_SRPGCR);
  77
  78         if (stop_mode) {
  79                 empgc0 |= MXC_SRPGCR_PCR;
  80                 empgc1 |= MXC_SRPGCR_PCR;
  81
  82                 __raw_writel(empgc0, MXC_SRPG_EMPGC0_SRPGCR);
  83                 __raw_writel(empgc1, MXC_SRPG_EMPGC1_SRPGCR);
  84         }
  85 }