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 } 195