arch/arm/mach-mvebu/pmsu.c

   1 /*
   2  * Power Management Service Unit(PMSU) support for Armada 370/XP platforms.
   3  *
   4  * Copyright (C) 2012 Marvell
   5  *
   6  * Yehuda Yitschak <yehuday@marvell.com>
   7  * Gregory Clement <gregory.clement@free-electrons.com>
   8  * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
   9  *
  10  * This file is licensed under the terms of the GNU General Public
  11  * License version 2.  This program is licensed "as is" without any
  12  * warranty of any kind, whether express or implied.
  13  *
  14  * The Armada 370 and Armada XP SOCs have a power management service
  15  * unit which is responsible for powering down and waking up CPUs and
  16  * other SOC units
  17  */
  18
  19 #define pr_fmt(fmt) "mvebu-pmsu: " fmt
  20
  21 #include <linux/cpu_pm.h>
  22 #include <linux/kernel.h>
  23 #include <linux/init.h>
  24 #include <linux/of_address.h>
  25 #include <linux/io.h>
  26 #include <linux/platform_device.h>
  27 #include <linux/smp.h>
  28 #include <linux/resource.h>
  29 #include <asm/cacheflush.h>
  30 #include <asm/cp15.h>
  31 #include <asm/smp_plat.h>
  32 #include <asm/suspend.h>
  33 #include <asm/tlbflush.h>
  34 #include "common.h"
  35
  36 static void __iomem *pmsu_mp_base;
  37
  38 #define PMSU_BASE_OFFSET    0x100
  39 #define PMSU_REG_SIZE       0x1000
  40
  41 /* PMSU MP registers */
  42 #define PMSU_CONTROL_AND_CONFIG(cpu)        ((cpu * 0x100) + 0x104)
  43 #define PMSU_CONTROL_AND_CONFIG_DFS_REQ         BIT(18)
  44 #define PMSU_CONTROL_AND_CONFIG_PWDDN_REQ       BIT(16)
  45 #define PMSU_CONTROL_AND_CONFIG_L2_PWDDN        BIT(20)
  46
  47 #define PMSU_CPU_POWER_DOWN_CONTROL(cpu)    ((cpu * 0x100) + 0x108)
  48
  49 #define PMSU_CPU_POWER_DOWN_DIS_SNP_Q_SKIP      BIT(0)
  50
  51 #define PMSU_STATUS_AND_MASK(cpu)           ((cpu * 0x100) + 0x10c)
  52 #define PMSU_STATUS_AND_MASK_CPU_IDLE_WAIT      BIT(16)
  53 #define PMSU_STATUS_AND_MASK_SNP_Q_EMPTY_WAIT   BIT(17)
  54 #define PMSU_STATUS_AND_MASK_IRQ_WAKEUP         BIT(20)
  55 #define PMSU_STATUS_AND_MASK_FIQ_WAKEUP         BIT(21)
  56 #define PMSU_STATUS_AND_MASK_DBG_WAKEUP         BIT(22)
  57 #define PMSU_STATUS_AND_MASK_IRQ_MASK           BIT(24)
  58 #define PMSU_STATUS_AND_MASK_FIQ_MASK           BIT(25)
  59
  60 #define PMSU_BOOT_ADDR_REDIRECT_OFFSET(cpu) ((cpu * 0x100) + 0x124)
  61
  62 /* PMSU fabric registers */
  63 #define L2C_NFABRIC_PM_CTL                  0x4
  64 #define L2C_NFABRIC_PM_CTL_PWR_DOWN             BIT(20)
  65
  66 extern void ll_disable_coherency(void);
  67 extern void ll_enable_coherency(void);
  68
  69 extern void armada_370_xp_cpu_resume(void);
  70
  71 static struct platform_device armada_xp_cpuidle_device = {
  72         .name = "cpuidle-armada-370-xp",
  73 };
  74
  75 static struct of_device_id of_pmsu_table[] = {
  76         { .compatible = "marvell,armada-370-pmsu", },
  77         { .compatible = "marvell,armada-370-xp-pmsu", },
  78         { .compatible = "marvell,armada-380-pmsu", },
  79         { /* end of list */ },
  80 };
  81
  82 void mvebu_pmsu_set_cpu_boot_addr(int hw_cpu, void *boot_addr)
  83 {
  84         writel(virt_to_phys(boot_addr), pmsu_mp_base +
  85                 PMSU_BOOT_ADDR_REDIRECT_OFFSET(hw_cpu));
  86 }
  87
  88 static int __init armada_370_xp_pmsu_init(void)
  89 {
  90         struct device_node *np;
  91         struct resource res;
  92         int ret = 0;
  93
  94         np = of_find_matching_node(NULL, of_pmsu_table);
  95         if (!np)
  96                 return 0;
  97
  98         pr_info("Initializing Power Management Service Unit\n");
  99
 100         if (of_address_to_resource(np, 0, &res)) {
 101                 pr_err("unable to get resource\n");
 102                 ret = -ENOENT;
 103                 goto out;
 104         }
 105
 106         if (of_device_is_compatible(np, "marvell,armada-370-xp-pmsu")) {
 107                 pr_warn(FW_WARN "deprecated pmsu binding\n");
 108                 res.start = res.start - PMSU_BASE_OFFSET;
 109                 res.end = res.start + PMSU_REG_SIZE - 1;
 110         }
 111
 112         if (!request_mem_region(res.start, resource_size(&res),
 113                                 np->full_name)) {
 114                 pr_err("unable to request region\n");
 115                 ret = -EBUSY;
 116                 goto out;
 117         }
 118
 119         pmsu_mp_base = ioremap(res.start, resource_size(&res));
 120         if (!pmsu_mp_base) {
 121                 pr_err("unable to map registers\n");
 122                 release_mem_region(res.start, resource_size(&res));
 123                 ret = -ENOMEM;
 124                 goto out;
 125         }
 126
 127  out:
 128         of_node_put(np);
 129         return ret;
 130 }
 131
 132 static void armada_370_xp_pmsu_enable_l2_powerdown_onidle(void)
 133 {
 134         u32 reg;
 135
 136         if (pmsu_mp_base == NULL)
 137                 return;
 138
 139         /* Enable L2 & Fabric powerdown in Deep-Idle mode - Fabric */
 140         reg = readl(pmsu_mp_base + L2C_NFABRIC_PM_CTL);
 141         reg |= L2C_NFABRIC_PM_CTL_PWR_DOWN;
 142         writel(reg, pmsu_mp_base + L2C_NFABRIC_PM_CTL);
 143 }
 144
 145 /* No locking is needed because we only access per-CPU registers */
 146 void armada_370_xp_pmsu_idle_prepare(bool deepidle)
 147 {
 148         unsigned int hw_cpu = cpu_logical_map(smp_processor_id());
 149         u32 reg;
 150
 151         if (pmsu_mp_base == NULL)
 152                 return;
 153
 154         /*
 155          * Adjust the PMSU configuration to wait for WFI signal, enable
 156          * IRQ and FIQ as wakeup events, set wait for snoop queue empty
 157          * indication and mask IRQ and FIQ from CPU
 158          */
 159         reg = readl(pmsu_mp_base + PMSU_STATUS_AND_MASK(hw_cpu));
 160         reg |= PMSU_STATUS_AND_MASK_CPU_IDLE_WAIT    |
 161                PMSU_STATUS_AND_MASK_IRQ_WAKEUP       |
 162                PMSU_STATUS_AND_MASK_FIQ_WAKEUP       |
 163                PMSU_STATUS_AND_MASK_SNP_Q_EMPTY_WAIT |
 164                PMSU_STATUS_AND_MASK_IRQ_MASK         |
 165                PMSU_STATUS_AND_MASK_FIQ_MASK;
 166         writel(reg, pmsu_mp_base + PMSU_STATUS_AND_MASK(hw_cpu));
 167
 168         reg = readl(pmsu_mp_base + PMSU_CONTROL_AND_CONFIG(hw_cpu));
 169         /* ask HW to power down the L2 Cache if needed */
 170         if (deepidle)
 171                 reg |= PMSU_CONTROL_AND_CONFIG_L2_PWDDN;
 172
 173         /* request power down */
 174         reg |= PMSU_CONTROL_AND_CONFIG_PWDDN_REQ;
 175         writel(reg, pmsu_mp_base + PMSU_CONTROL_AND_CONFIG(hw_cpu));
 176
 177         /* Disable snoop disable by HW - SW is taking care of it */
 178         reg = readl(pmsu_mp_base + PMSU_CPU_POWER_DOWN_CONTROL(hw_cpu));
 179         reg |= PMSU_CPU_POWER_DOWN_DIS_SNP_Q_SKIP;
 180         writel(reg, pmsu_mp_base + PMSU_CPU_POWER_DOWN_CONTROL(hw_cpu));
 181 }
 182
 183 static noinline int do_armada_370_xp_cpu_suspend(unsigned long deepidle)
 184 {
 185         armada_370_xp_pmsu_idle_prepare(deepidle);
 186
 187         v7_exit_coherency_flush(all);
 188
 189         ll_disable_coherency();
 190
 191         dsb();
 192
 193         wfi();
 194
 195         /* If we are here, wfi failed. As processors run out of
 196          * coherency for some time, tlbs might be stale, so flush them
 197          */
 198         local_flush_tlb_all();
 199
 200         ll_enable_coherency();
 201
 202         /* Test the CR_C bit and set it if it was cleared */
 203         asm volatile(
 204         "mrc    p15, 0, %0, c1, c0, 0 \n\t"
 205         "tst    %0, #(1 << 2) \n\t"
 206         "orreq  %0, %0, #(1 << 2) \n\t"
 207         "mcreq  p15, 0, %0, c1, c0, 0 \n\t"
 208         "isb    "
 209         : : "r" (0));
 210
 211         pr_warn("Failed to suspend the system\n");
 212
 213         return 0;
 214 }
 215
 216 static int armada_370_xp_cpu_suspend(unsigned long deepidle)
 217 {
 218         return cpu_suspend(deepidle, do_armada_370_xp_cpu_suspend);
 219 }
 220
 221 /* No locking is needed because we only access per-CPU registers */
 222 static noinline void armada_370_xp_pmsu_idle_restore(void)
 223 {
 224         unsigned int hw_cpu = cpu_logical_map(smp_processor_id());
 225         u32 reg;
 226
 227         if (pmsu_mp_base == NULL)
 228                 return;
 229
 230         /* cancel ask HW to power down the L2 Cache if possible */
 231         reg = readl(pmsu_mp_base + PMSU_CONTROL_AND_CONFIG(hw_cpu));
 232         reg &= ~PMSU_CONTROL_AND_CONFIG_L2_PWDDN;
 233         writel(reg, pmsu_mp_base + PMSU_CONTROL_AND_CONFIG(hw_cpu));
 234
 235         /* cancel Enable wakeup events and mask interrupts */
 236         reg = readl(pmsu_mp_base + PMSU_STATUS_AND_MASK(hw_cpu));
 237         reg &= ~(PMSU_STATUS_AND_MASK_IRQ_WAKEUP | PMSU_STATUS_AND_MASK_FIQ_WAKEUP);
 238         reg &= ~PMSU_STATUS_AND_MASK_CPU_IDLE_WAIT;
 239         reg &= ~PMSU_STATUS_AND_MASK_SNP_Q_EMPTY_WAIT;
 240         reg &= ~(PMSU_STATUS_AND_MASK_IRQ_MASK | PMSU_STATUS_AND_MASK_FIQ_MASK);
 241         writel(reg, pmsu_mp_base + PMSU_STATUS_AND_MASK(hw_cpu));
 242 }
 243
 244 static int armada_370_xp_cpu_pm_notify(struct notifier_block *self,
 245                                     unsigned long action, void *hcpu)
 246 {
 247         if (action == CPU_PM_ENTER) {
 248                 unsigned int hw_cpu = cpu_logical_map(smp_processor_id());
 249                 mvebu_pmsu_set_cpu_boot_addr(hw_cpu, armada_370_xp_cpu_resume);
 250         } else if (action == CPU_PM_EXIT) {
 251                 armada_370_xp_pmsu_idle_restore();
 252         }
 253
 254         return NOTIFY_OK;
 255 }
 256
 257 static struct notifier_block armada_370_xp_cpu_pm_notifier = {
 258         .notifier_call = armada_370_xp_cpu_pm_notify,
 259 };
 260
 261 int __init armada_370_xp_cpu_pm_init(void)
 262 {
 263         struct device_node *np;
 264
 265         /*
 266          * Check that all the requirements are available to enable
 267          * cpuidle. So far, it is only supported on Armada XP, cpuidle
 268          * needs the coherency fabric and the PMSU enabled
 269          */
 270
 271         if (!of_machine_is_compatible("marvell,armadaxp"))
 272                 return 0;
 273
 274         np = of_find_compatible_node(NULL, NULL, "marvell,coherency-fabric");
 275         if (!np)
 276                 return 0;
 277         of_node_put(np);
 278
 279         np = of_find_matching_node(NULL, of_pmsu_table);
 280         if (!np)
 281                 return 0;
 282         of_node_put(np);
 283
 284         armada_370_xp_pmsu_enable_l2_powerdown_onidle();
 285         armada_xp_cpuidle_device.dev.platform_data = armada_370_xp_cpu_suspend;
 286         platform_device_register(&armada_xp_cpuidle_device);
 287         cpu_pm_register_notifier(&armada_370_xp_cpu_pm_notifier);
 288
 289         return 0;
 290 }
 291
 292 arch_initcall(armada_370_xp_cpu_pm_init);
 293 early_initcall(armada_370_xp_pmsu_init);