arch/arm/mach-ux500/pm.c

   1 /*
   2  * Copyright (C) ST-Ericsson SA 2010-2013
   3  * Author: Rickard Andersson <rickard.andersson@stericsson.com> for
   4  *         ST-Ericsson.
   5  * Author: Daniel Lezcano <daniel.lezcano@linaro.org> for Linaro.
   6  * Author: Ulf Hansson <ulf.hansson@linaro.org> for Linaro.
   7  *
   8  * License terms: GNU General Public License (GPL) version 2
   9  *
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/irqchip/arm-gic.h>
  14 #include <linux/delay.h>
  15 #include <linux/io.h>
  16 #include <linux/suspend.h>
  17 #include <linux/platform_data/arm-ux500-pm.h>
  18
  19 #include "db8500-regs.h"
  20
  21 /* ARM WFI Standby signal register */
  22 #define PRCM_ARM_WFI_STANDBY    (prcmu_base + 0x130)
  23 #define PRCM_ARM_WFI_STANDBY_WFI0               0x08
  24 #define PRCM_ARM_WFI_STANDBY_WFI1               0x10
  25 #define PRCM_IOCR               (prcmu_base + 0x310)
  26 #define PRCM_IOCR_IOFORCE                       0x1
  27
  28 /* Dual A9 core interrupt management unit registers */
  29 #define PRCM_A9_MASK_REQ        (prcmu_base + 0x328)
  30 #define PRCM_A9_MASK_REQ_PRCM_A9_MASK_REQ       0x1
  31
  32 #define PRCM_A9_MASK_ACK        (prcmu_base + 0x32c)
  33 #define PRCM_ARMITMSK31TO0      (prcmu_base + 0x11c)
  34 #define PRCM_ARMITMSK63TO32     (prcmu_base + 0x120)
  35 #define PRCM_ARMITMSK95TO64     (prcmu_base + 0x124)
  36 #define PRCM_ARMITMSK127TO96    (prcmu_base + 0x128)
  37 #define PRCM_POWER_STATE_VAL    (prcmu_base + 0x25C)
  38 #define PRCM_ARMITVAL31TO0      (prcmu_base + 0x260)
  39 #define PRCM_ARMITVAL63TO32     (prcmu_base + 0x264)
  40 #define PRCM_ARMITVAL95TO64     (prcmu_base + 0x268)
  41 #define PRCM_ARMITVAL127TO96    (prcmu_base + 0x26C)
  42
  43 static void __iomem *prcmu_base;
  44
  45 /* This function decouple the gic from the prcmu */
  46 int prcmu_gic_decouple(void)
  47 {
  48         u32 val = readl(PRCM_A9_MASK_REQ);
  49
  50         /* Set bit 0 register value to 1 */
  51         writel(val | PRCM_A9_MASK_REQ_PRCM_A9_MASK_REQ,
  52                PRCM_A9_MASK_REQ);
  53
  54         /* Make sure the register is updated */
  55         readl(PRCM_A9_MASK_REQ);
  56
  57         /* Wait a few cycles for the gic mask completion */
  58         udelay(1);
  59
  60         return 0;
  61 }
  62
  63 /* This function recouple the gic with the prcmu */
  64 int prcmu_gic_recouple(void)
  65 {
  66         u32 val = readl(PRCM_A9_MASK_REQ);
  67
  68         /* Set bit 0 register value to 0 */
  69         writel(val & ~PRCM_A9_MASK_REQ_PRCM_A9_MASK_REQ, PRCM_A9_MASK_REQ);
  70
  71         return 0;
  72 }
  73
  74 #define PRCMU_GIC_NUMBER_REGS 5
  75
  76 /*
  77  * This function checks if there are pending irq on the gic. It only
  78  * makes sense if the gic has been decoupled before with the
  79  * db8500_prcmu_gic_decouple function. Disabling an interrupt only
  80  * disables the forwarding of the interrupt to any CPU interface. It
  81  * does not prevent the interrupt from changing state, for example
  82  * becoming pending, or active and pending if it is already
  83  * active. Hence, we have to check the interrupt is pending *and* is
  84  * active.
  85  */
  86 bool prcmu_gic_pending_irq(void)
  87 {
  88         u32 pr; /* Pending register */
  89         u32 er; /* Enable register */
  90         void __iomem *dist_base = __io_address(U8500_GIC_DIST_BASE);
  91         int i;
  92
  93         /* 5 registers. STI & PPI not skipped */
  94         for (i = 0; i < PRCMU_GIC_NUMBER_REGS; i++) {
  95
  96                 pr = readl_relaxed(dist_base + GIC_DIST_PENDING_SET + i * 4);
  97                 er = readl_relaxed(dist_base + GIC_DIST_ENABLE_SET + i * 4);
  98
  99                 if (pr & er)
 100                         return true; /* There is a pending interrupt */
 101         }
 102
 103         return false;
 104 }
 105
 106 /*
 107  * This function checks if there are pending interrupt on the
 108  * prcmu which has been delegated to monitor the irqs with the
 109  * db8500_prcmu_copy_gic_settings function.
 110  */
 111 bool prcmu_pending_irq(void)
 112 {
 113         u32 it, im;
 114         int i;
 115
 116         for (i = 0; i < PRCMU_GIC_NUMBER_REGS - 1; i++) {
 117                 it = readl(PRCM_ARMITVAL31TO0 + i * 4);
 118                 im = readl(PRCM_ARMITMSK31TO0 + i * 4);
 119                 if (it & im)
 120                         return true; /* There is a pending interrupt */
 121         }
 122
 123         return false;
 124 }
 125
 126 /*
 127  * This function checks if the specified cpu is in in WFI. It's usage
 128  * makes sense only if the gic is decoupled with the db8500_prcmu_gic_decouple
 129  * function. Of course passing smp_processor_id() to this function will
 130  * always return false...
 131  */
 132 bool prcmu_is_cpu_in_wfi(int cpu)
 133 {
 134         return readl(PRCM_ARM_WFI_STANDBY) & cpu ? PRCM_ARM_WFI_STANDBY_WFI1 :
 135                      PRCM_ARM_WFI_STANDBY_WFI0;
 136 }
 137
 138 /*
 139  * This function copies the gic SPI settings to the prcmu in order to
 140  * monitor them and abort/finish the retention/off sequence or state.
 141  */
 142 int prcmu_copy_gic_settings(void)
 143 {
 144         u32 er; /* Enable register */
 145         void __iomem *dist_base = __io_address(U8500_GIC_DIST_BASE);
 146         int i;
 147
 148         /* We skip the STI and PPI */
 149         for (i = 0; i < PRCMU_GIC_NUMBER_REGS - 1; i++) {
 150                 er = readl_relaxed(dist_base +
 151                                    GIC_DIST_ENABLE_SET + (i + 1) * 4);
 152                 writel(er, PRCM_ARMITMSK31TO0 + i * 4);
 153         }
 154
 155         return 0;
 156 }
 157
 158 #ifdef CONFIG_SUSPEND
 159 static int ux500_suspend_enter(suspend_state_t state)
 160 {
 161         cpu_do_idle();
 162         return 0;
 163 }
 164
 165 static int ux500_suspend_valid(suspend_state_t state)
 166 {
 167         return state == PM_SUSPEND_MEM || state == PM_SUSPEND_STANDBY;
 168 }
 169
 170 static const struct platform_suspend_ops ux500_suspend_ops = {
 171         .enter        = ux500_suspend_enter,
 172         .valid        = ux500_suspend_valid,
 173 };
 174 #define UX500_SUSPEND_OPS       (&ux500_suspend_ops)
 175 #else
 176 #define UX500_SUSPEND_OPS       NULL
 177 #endif
 178
 179 void __init ux500_pm_init(u32 phy_base, u32 size)
 180 {
 181         prcmu_base = ioremap(phy_base, size);
 182         if (!prcmu_base) {
 183                 pr_err("could not remap PRCMU for PM functions\n");
 184                 return;
 185         }
 186         /*
 187          * On watchdog reboot the GIC is in some cases decoupled.
 188          * This will make sure that the GIC is correctly configured.
 189          */
 190         prcmu_gic_recouple();
 191
 192         /* Set up ux500 suspend callbacks. */
 193         suspend_set_ops(UX500_SUSPEND_OPS);
 194 }