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/clk.h>
  22 #include <linux/cpu_pm.h>
  23 #include <linux/cpufreq-dt.h>
  24 #include <linux/delay.h>
  25 #include <linux/init.h>
  26 #include <linux/io.h>
  27 #include <linux/kernel.h>
  28 #include <linux/mbus.h>
  29 #include <linux/of_address.h>
  30 #include <linux/of_device.h>
  31 #include <linux/platform_device.h>
  32 #include <linux/pm_opp.h>
  33 #include <linux/resource.h>
  34 #include <linux/slab.h>
  35 #include <linux/smp.h>
  36 #include <asm/cacheflush.h>
  37 #include <asm/cp15.h>
  38 #include <asm/smp_scu.h>
  39 #include <asm/smp_plat.h>
  40 #include <asm/suspend.h>
  41 #include <asm/tlbflush.h>
  42 #include "common.h"
  43
  44
  45 #define PMSU_BASE_OFFSET    0x100
  46 #define PMSU_REG_SIZE       0x1000
  47
  48 /* PMSU MP registers */
  49 #define PMSU_CONTROL_AND_CONFIG(cpu)        ((cpu * 0x100) + 0x104)
  50 #define PMSU_CONTROL_AND_CONFIG_DFS_REQ         BIT(18)
  51 #define PMSU_CONTROL_AND_CONFIG_PWDDN_REQ       BIT(16)
  52 #define PMSU_CONTROL_AND_CONFIG_L2_PWDDN        BIT(20)
  53
  54 #define PMSU_CPU_POWER_DOWN_CONTROL(cpu)    ((cpu * 0x100) + 0x108)
  55
  56 #define PMSU_CPU_POWER_DOWN_DIS_SNP_Q_SKIP      BIT(0)
  57
  58 #define PMSU_STATUS_AND_MASK(cpu)           ((cpu * 0x100) + 0x10c)
  59 #define PMSU_STATUS_AND_MASK_CPU_IDLE_WAIT      BIT(16)
  60 #define PMSU_STATUS_AND_MASK_SNP_Q_EMPTY_WAIT   BIT(17)
  61 #define PMSU_STATUS_AND_MASK_IRQ_WAKEUP         BIT(20)
  62 #define PMSU_STATUS_AND_MASK_FIQ_WAKEUP         BIT(21)
  63 #define PMSU_STATUS_AND_MASK_DBG_WAKEUP         BIT(22)
  64 #define PMSU_STATUS_AND_MASK_IRQ_MASK           BIT(24)
  65 #define PMSU_STATUS_AND_MASK_FIQ_MASK           BIT(25)
  66
  67 #define PMSU_EVENT_STATUS_AND_MASK(cpu)     ((cpu * 0x100) + 0x120)
  68 #define PMSU_EVENT_STATUS_AND_MASK_DFS_DONE        BIT(1)
  69 #define PMSU_EVENT_STATUS_AND_MASK_DFS_DONE_MASK   BIT(17)
  70
  71 #define PMSU_BOOT_ADDR_REDIRECT_OFFSET(cpu) ((cpu * 0x100) + 0x124)
  72
  73 /* PMSU fabric registers */
  74 #define L2C_NFABRIC_PM_CTL                  0x4
  75 #define L2C_NFABRIC_PM_CTL_PWR_DOWN             BIT(20)
  76
  77 /* PMSU delay registers */
  78 #define PMSU_POWERDOWN_DELAY                0xF04
  79 #define PMSU_POWERDOWN_DELAY_PMU                BIT(1)
  80 #define PMSU_POWERDOWN_DELAY_MASK               0xFFFE
  81 #define PMSU_DFLT_ARMADA38X_DELAY               0x64
  82
  83 /* CA9 MPcore SoC Control registers */
  84
  85 #define MPCORE_RESET_CTL                    0x64
  86 #define MPCORE_RESET_CTL_L2                     BIT(0)
  87 #define MPCORE_RESET_CTL_DEBUG                  BIT(16)
  88
  89 #define SRAM_PHYS_BASE  0xFFFF0000
  90 #define BOOTROM_BASE    0xFFF00000
  91 #define BOOTROM_SIZE    0x100000
  92
  93 #define ARMADA_370_CRYPT0_ENG_TARGET   0x9
  94 #define ARMADA_370_CRYPT0_ENG_ATTR     0x1
  95
  96 extern void ll_disable_coherency(void);
  97 extern void ll_enable_coherency(void);
  98
  99 extern void armada_370_xp_cpu_resume(void);
 100 extern void armada_38x_cpu_resume(void);
 101
 102 static phys_addr_t pmsu_mp_phys_base;
 103 static void __iomem *pmsu_mp_base;
 104
 105 static void *mvebu_cpu_resume;
 106
 107 static const struct of_device_id of_pmsu_table[] = {
 108         { .compatible = "marvell,armada-370-pmsu", },
 109         { .compatible = "marvell,armada-370-xp-pmsu", },
 110         { .compatible = "marvell,armada-380-pmsu", },
 111         { /* end of list */ },
 112 };
 113
 114 void mvebu_pmsu_set_cpu_boot_addr(int hw_cpu, void *boot_addr)
 115 {
 116         writel(virt_to_phys(boot_addr), pmsu_mp_base +
 117                 PMSU_BOOT_ADDR_REDIRECT_OFFSET(hw_cpu));
 118 }
 119
 120 extern unsigned char mvebu_boot_wa_start;
 121 extern unsigned char mvebu_boot_wa_end;
 122
 123 /*
 124  * This function sets up the boot address workaround needed for SMP
 125  * boot on Armada 375 Z1 and cpuidle on Armada 370. It unmaps the
 126  * BootROM Mbus window, and instead remaps a crypto SRAM into which a
 127  * custom piece of code is copied to replace the problematic BootROM.
 128  */
 129 int mvebu_setup_boot_addr_wa(unsigned int crypto_eng_target,
 130                              unsigned int crypto_eng_attribute,
 131                              phys_addr_t resume_addr_reg)
 132 {
 133         void __iomem *sram_virt_base;
 134         u32 code_len = &mvebu_boot_wa_end - &mvebu_boot_wa_start;
 135
 136         mvebu_mbus_del_window(BOOTROM_BASE, BOOTROM_SIZE);
 137         mvebu_mbus_add_window_by_id(crypto_eng_target, crypto_eng_attribute,
 138                                     SRAM_PHYS_BASE, SZ_64K);
 139
 140         sram_virt_base = ioremap(SRAM_PHYS_BASE, SZ_64K);
 141         if (!sram_virt_base) {
 142                 pr_err("Unable to map SRAM to setup the boot address WA\n");
 143                 return -ENOMEM;
 144         }
 145
 146         memcpy(sram_virt_base, &mvebu_boot_wa_start, code_len);
 147
 148         /*
 149          * The last word of the code copied in SRAM must contain the
 150          * physical base address of the PMSU register. We
 151          * intentionally store this address in the native endianness
 152          * of the system.
 153          */
 154         __raw_writel((unsigned long)resume_addr_reg,
 155                      sram_virt_base + code_len - 4);
 156
 157         iounmap(sram_virt_base);
 158
 159         return 0;
 160 }
 161
 162 static int __init mvebu_v7_pmsu_init(void)
 163 {
 164         struct device_node *np;
 165         struct resource res;
 166         int ret = 0;
 167
 168         np = of_find_matching_node(NULL, of_pmsu_table);
 169         if (!np)
 170                 return 0;
 171
 172         pr_info("Initializing Power Management Service Unit\n");
 173
 174         if (of_address_to_resource(np, 0, &res)) {
 175                 pr_err("unable to get resource\n");
 176                 ret = -ENOENT;
 177                 goto out;
 178         }
 179
 180         if (of_device_is_compatible(np, "marvell,armada-370-xp-pmsu")) {
 181                 pr_warn(FW_WARN "deprecated pmsu binding\n");
 182                 res.start = res.start - PMSU_BASE_OFFSET;
 183                 res.end = res.start + PMSU_REG_SIZE - 1;
 184         }
 185
 186         if (!request_mem_region(res.start, resource_size(&res),
 187                                 np->full_name)) {
 188                 pr_err("unable to request region\n");
 189                 ret = -EBUSY;
 190                 goto out;
 191         }
 192
 193         pmsu_mp_phys_base = res.start;
 194
 195         pmsu_mp_base = ioremap(res.start, resource_size(&res));
 196         if (!pmsu_mp_base) {
 197                 pr_err("unable to map registers\n");
 198                 release_mem_region(res.start, resource_size(&res));
 199                 ret = -ENOMEM;
 200                 goto out;
 201         }
 202
 203  out:
 204         of_node_put(np);
 205         return ret;
 206 }
 207
 208 static void mvebu_v7_pmsu_enable_l2_powerdown_onidle(void)
 209 {
 210         u32 reg;
 211
 212         if (pmsu_mp_base == NULL)
 213                 return;
 214
 215         /* Enable L2 & Fabric powerdown in Deep-Idle mode - Fabric */
 216         reg = readl(pmsu_mp_base + L2C_NFABRIC_PM_CTL);
 217         reg |= L2C_NFABRIC_PM_CTL_PWR_DOWN;
 218         writel(reg, pmsu_mp_base + L2C_NFABRIC_PM_CTL);
 219 }
 220
 221 enum pmsu_idle_prepare_flags {
 222         PMSU_PREPARE_NORMAL = 0,
 223         PMSU_PREPARE_DEEP_IDLE = BIT(0),
 224         PMSU_PREPARE_SNOOP_DISABLE = BIT(1),
 225 };
 226
 227 /* No locking is needed because we only access per-CPU registers */
 228 static int mvebu_v7_pmsu_idle_prepare(unsigned long flags)
 229 {
 230         unsigned int hw_cpu = cpu_logical_map(smp_processor_id());
 231         u32 reg;
 232
 233         if (pmsu_mp_base == NULL)
 234                 return -EINVAL;
 235
 236         /*
 237          * Adjust the PMSU configuration to wait for WFI signal, enable
 238          * IRQ and FIQ as wakeup events, set wait for snoop queue empty
 239          * indication and mask IRQ and FIQ from CPU
 240          */
 241         reg = readl(pmsu_mp_base + PMSU_STATUS_AND_MASK(hw_cpu));
 242         reg |= PMSU_STATUS_AND_MASK_CPU_IDLE_WAIT    |
 243                PMSU_STATUS_AND_MASK_IRQ_WAKEUP       |
 244                PMSU_STATUS_AND_MASK_FIQ_WAKEUP       |
 245                PMSU_STATUS_AND_MASK_SNP_Q_EMPTY_WAIT |
 246                PMSU_STATUS_AND_MASK_IRQ_MASK         |
 247                PMSU_STATUS_AND_MASK_FIQ_MASK;
 248         writel(reg, pmsu_mp_base + PMSU_STATUS_AND_MASK(hw_cpu));
 249
 250         reg = readl(pmsu_mp_base + PMSU_CONTROL_AND_CONFIG(hw_cpu));
 251         /* ask HW to power down the L2 Cache if needed */
 252         if (flags & PMSU_PREPARE_DEEP_IDLE)
 253                 reg |= PMSU_CONTROL_AND_CONFIG_L2_PWDDN;
 254
 255         /* request power down */
 256         reg |= PMSU_CONTROL_AND_CONFIG_PWDDN_REQ;
 257         writel(reg, pmsu_mp_base + PMSU_CONTROL_AND_CONFIG(hw_cpu));
 258
 259         if (flags & PMSU_PREPARE_SNOOP_DISABLE) {
 260                 /* Disable snoop disable by HW - SW is taking care of it */
 261                 reg = readl(pmsu_mp_base + PMSU_CPU_POWER_DOWN_CONTROL(hw_cpu));
 262                 reg |= PMSU_CPU_POWER_DOWN_DIS_SNP_Q_SKIP;
 263                 writel(reg, pmsu_mp_base + PMSU_CPU_POWER_DOWN_CONTROL(hw_cpu));
 264         }
 265
 266         return 0;
 267 }
 268
 269 int armada_370_xp_pmsu_idle_enter(unsigned long deepidle)
 270 {
 271         unsigned long flags = PMSU_PREPARE_SNOOP_DISABLE;
 272         int ret;
 273
 274         if (deepidle)
 275                 flags |= PMSU_PREPARE_DEEP_IDLE;
 276
 277         ret = mvebu_v7_pmsu_idle_prepare(flags);
 278         if (ret)
 279                 return ret;
 280
 281         v7_exit_coherency_flush(all);
 282
 283         ll_disable_coherency();
 284
 285         dsb();
 286
 287         wfi();
 288
 289         /* If we are here, wfi failed. As processors run out of
 290          * coherency for some time, tlbs might be stale, so flush them
 291          */
 292         local_flush_tlb_all();
 293
 294         ll_enable_coherency();
 295
 296         /* Test the CR_C bit and set it if it was cleared */
 297         asm volatile(
 298         "mrc    p15, 0, r0, c1, c0, 0 \n\t"
 299         "tst    r0, #(1 << 2) \n\t"
 300         "orreq  r0, r0, #(1 << 2) \n\t"
 301         "mcreq  p15, 0, r0, c1, c0, 0 \n\t"
 302         "isb    "
 303         : : : "r0");
 304
 305         pr_debug("Failed to suspend the system\n");
 306
 307         return 0;
 308 }
 309
 310 static int armada_370_xp_cpu_suspend(unsigned long deepidle)
 311 {
 312         return cpu_suspend(deepidle, armada_370_xp_pmsu_idle_enter);
 313 }
 314
 315 int armada_38x_do_cpu_suspend(unsigned long deepidle)
 316 {
 317         unsigned long flags = 0;
 318
 319         if (deepidle)
 320                 flags |= PMSU_PREPARE_DEEP_IDLE;
 321
 322         mvebu_v7_pmsu_idle_prepare(flags);
 323         /*
 324          * Already flushed cache, but do it again as the outer cache
 325          * functions dirty the cache with spinlocks
 326          */
 327         v7_exit_coherency_flush(louis);
 328
 329         scu_power_mode(mvebu_get_scu_base(), SCU_PM_POWEROFF);
 330
 331         cpu_do_idle();
 332
 333         return 1;
 334 }
 335
 336 static int armada_38x_cpu_suspend(unsigned long deepidle)
 337 {
 338         return cpu_suspend(false, armada_38x_do_cpu_suspend);
 339 }
 340
 341 /* No locking is needed because we only access per-CPU registers */
 342 void mvebu_v7_pmsu_idle_exit(void)
 343 {
 344         unsigned int hw_cpu = cpu_logical_map(smp_processor_id());
 345         u32 reg;
 346
 347         if (pmsu_mp_base == NULL)
 348                 return;
 349         /* cancel ask HW to power down the L2 Cache if possible */
 350         reg = readl(pmsu_mp_base + PMSU_CONTROL_AND_CONFIG(hw_cpu));
 351         reg &= ~PMSU_CONTROL_AND_CONFIG_L2_PWDDN;
 352         writel(reg, pmsu_mp_base + PMSU_CONTROL_AND_CONFIG(hw_cpu));
 353
 354         /* cancel Enable wakeup events and mask interrupts */
 355         reg = readl(pmsu_mp_base + PMSU_STATUS_AND_MASK(hw_cpu));
 356         reg &= ~(PMSU_STATUS_AND_MASK_IRQ_WAKEUP | PMSU_STATUS_AND_MASK_FIQ_WAKEUP);
 357         reg &= ~PMSU_STATUS_AND_MASK_CPU_IDLE_WAIT;
 358         reg &= ~PMSU_STATUS_AND_MASK_SNP_Q_EMPTY_WAIT;
 359         reg &= ~(PMSU_STATUS_AND_MASK_IRQ_MASK | PMSU_STATUS_AND_MASK_FIQ_MASK);
 360         writel(reg, pmsu_mp_base + PMSU_STATUS_AND_MASK(hw_cpu));
 361 }
 362
 363 static int mvebu_v7_cpu_pm_notify(struct notifier_block *self,
 364                                     unsigned long action, void *hcpu)
 365 {
 366         if (action == CPU_PM_ENTER) {
 367                 unsigned int hw_cpu = cpu_logical_map(smp_processor_id());
 368                 mvebu_pmsu_set_cpu_boot_addr(hw_cpu, mvebu_cpu_resume);
 369         } else if (action == CPU_PM_EXIT) {
 370                 mvebu_v7_pmsu_idle_exit();
 371         }
 372
 373         return NOTIFY_OK;
 374 }
 375
 376 static struct notifier_block mvebu_v7_cpu_pm_notifier = {
 377         .notifier_call = mvebu_v7_cpu_pm_notify,
 378 };
 379
 380 static struct platform_device mvebu_v7_cpuidle_device;
 381
 382 static __init int armada_370_cpuidle_init(void)
 383 {
 384         struct device_node *np;
 385         phys_addr_t redirect_reg;
 386
 387         np = of_find_compatible_node(NULL, NULL, "marvell,coherency-fabric");
 388         if (!np)
 389                 return -ENODEV;
 390         of_node_put(np);
 391
 392         /*
 393          * On Armada 370, there is "a slow exit process from the deep
 394          * idle state due to heavy L1/L2 cache cleanup operations
 395          * performed by the BootROM software". To avoid this, we
 396          * replace the restart code of the bootrom by a a simple jump
 397          * to the boot address. Then the code located at this boot
 398          * address will take care of the initialization.
 399          */
 400         redirect_reg = pmsu_mp_phys_base + PMSU_BOOT_ADDR_REDIRECT_OFFSET(0);
 401         mvebu_setup_boot_addr_wa(ARMADA_370_CRYPT0_ENG_TARGET,
 402                                  ARMADA_370_CRYPT0_ENG_ATTR,
 403                                  redirect_reg);
 404
 405         mvebu_cpu_resume = armada_370_xp_cpu_resume;
 406         mvebu_v7_cpuidle_device.dev.platform_data = armada_370_xp_cpu_suspend;
 407         mvebu_v7_cpuidle_device.name = "cpuidle-armada-370";
 408
 409         return 0;
 410 }
 411
 412 static __init int armada_38x_cpuidle_init(void)
 413 {
 414         struct device_node *np;
 415         void __iomem *mpsoc_base;
 416         u32 reg;
 417
 418         pr_warn("CPU idle is currently broken on Armada 38x: disabling\n");
 419         return 0;
 420
 421         np = of_find_compatible_node(NULL, NULL,
 422                                      "marvell,armada-380-coherency-fabric");
 423         if (!np)
 424                 return -ENODEV;
 425         of_node_put(np);
 426
 427         np = of_find_compatible_node(NULL, NULL,
 428                                      "marvell,armada-380-mpcore-soc-ctrl");
 429         if (!np)
 430                 return -ENODEV;
 431         mpsoc_base = of_iomap(np, 0);
 432         BUG_ON(!mpsoc_base);
 433         of_node_put(np);
 434
 435         /* Set up reset mask when powering down the cpus */
 436         reg = readl(mpsoc_base + MPCORE_RESET_CTL);
 437         reg |= MPCORE_RESET_CTL_L2;
 438         reg |= MPCORE_RESET_CTL_DEBUG;
 439         writel(reg, mpsoc_base + MPCORE_RESET_CTL);
 440         iounmap(mpsoc_base);
 441
 442         /* Set up delay */
 443         reg = readl(pmsu_mp_base + PMSU_POWERDOWN_DELAY);
 444         reg &= ~PMSU_POWERDOWN_DELAY_MASK;
 445         reg |= PMSU_DFLT_ARMADA38X_DELAY;
 446         reg |= PMSU_POWERDOWN_DELAY_PMU;
 447         writel(reg, pmsu_mp_base + PMSU_POWERDOWN_DELAY);
 448
 449         mvebu_cpu_resume = armada_38x_cpu_resume;
 450         mvebu_v7_cpuidle_device.dev.platform_data = armada_38x_cpu_suspend;
 451         mvebu_v7_cpuidle_device.name = "cpuidle-armada-38x";
 452
 453         return 0;
 454 }
 455
 456 static __init int armada_xp_cpuidle_init(void)
 457 {
 458         struct device_node *np;
 459
 460         np = of_find_compatible_node(NULL, NULL, "marvell,coherency-fabric");
 461         if (!np)
 462                 return -ENODEV;
 463         of_node_put(np);
 464
 465         mvebu_cpu_resume = armada_370_xp_cpu_resume;
 466         mvebu_v7_cpuidle_device.dev.platform_data = armada_370_xp_cpu_suspend;
 467         mvebu_v7_cpuidle_device.name = "cpuidle-armada-xp";
 468
 469         return 0;
 470 }
 471
 472 static int __init mvebu_v7_cpu_pm_init(void)
 473 {
 474         struct device_node *np;
 475         int ret;
 476
 477         np = of_find_matching_node(NULL, of_pmsu_table);
 478         if (!np)
 479                 return 0;
 480         of_node_put(np);
 481
 482         /*
 483          * Currently the CPU idle support for Armada 38x is broken, as
 484          * the CPU hotplug uses some of the CPU idle functions it is
 485          * broken too, so let's disable it
 486          */
 487         if (of_machine_is_compatible("marvell,armada380")) {
 488                 cpu_hotplug_disable();
 489                 pr_warn("CPU hotplug support is currently broken on Armada 38x: disabling\n");
 490         }
 491
 492         if (of_machine_is_compatible("marvell,armadaxp"))
 493                 ret = armada_xp_cpuidle_init();
 494         else if (of_machine_is_compatible("marvell,armada370"))
 495                 ret = armada_370_cpuidle_init();
 496         else if (of_machine_is_compatible("marvell,armada380"))
 497                 ret = armada_38x_cpuidle_init();
 498         else
 499                 return 0;
 500
 501         if (ret)
 502                 return ret;
 503
 504         mvebu_v7_pmsu_enable_l2_powerdown_onidle();
 505         if (mvebu_v7_cpuidle_device.name)
 506                 platform_device_register(&mvebu_v7_cpuidle_device);
 507         cpu_pm_register_notifier(&mvebu_v7_cpu_pm_notifier);
 508
 509         return 0;
 510 }
 511
 512 arch_initcall(mvebu_v7_cpu_pm_init);
 513 early_initcall(mvebu_v7_pmsu_init);
 514
 515 static void mvebu_pmsu_dfs_request_local(void *data)
 516 {
 517         u32 reg;
 518         u32 cpu = smp_processor_id();
 519         unsigned long flags;
 520
 521         local_irq_save(flags);
 522
 523         /* Prepare to enter idle */
 524         reg = readl(pmsu_mp_base + PMSU_STATUS_AND_MASK(cpu));
 525         reg |= PMSU_STATUS_AND_MASK_CPU_IDLE_WAIT |
 526                PMSU_STATUS_AND_MASK_IRQ_MASK     |
 527                PMSU_STATUS_AND_MASK_FIQ_MASK;
 528         writel(reg, pmsu_mp_base + PMSU_STATUS_AND_MASK(cpu));
 529
 530         /* Request the DFS transition */
 531         reg = readl(pmsu_mp_base + PMSU_CONTROL_AND_CONFIG(cpu));
 532         reg |= PMSU_CONTROL_AND_CONFIG_DFS_REQ;
 533         writel(reg, pmsu_mp_base + PMSU_CONTROL_AND_CONFIG(cpu));
 534
 535         /* The fact of entering idle will trigger the DFS transition */
 536         wfi();
 537
 538         /*
 539          * We're back from idle, the DFS transition has completed,
 540          * clear the idle wait indication.
 541          */
 542         reg = readl(pmsu_mp_base + PMSU_STATUS_AND_MASK(cpu));
 543         reg &= ~PMSU_STATUS_AND_MASK_CPU_IDLE_WAIT;
 544         writel(reg, pmsu_mp_base + PMSU_STATUS_AND_MASK(cpu));
 545
 546         local_irq_restore(flags);
 547 }
 548
 549 int mvebu_pmsu_dfs_request(int cpu)
 550 {
 551         unsigned long timeout;
 552         int hwcpu = cpu_logical_map(cpu);
 553         u32 reg;
 554
 555         /* Clear any previous DFS DONE event */
 556         reg = readl(pmsu_mp_base + PMSU_EVENT_STATUS_AND_MASK(hwcpu));
 557         reg &= ~PMSU_EVENT_STATUS_AND_MASK_DFS_DONE;
 558         writel(reg, pmsu_mp_base + PMSU_EVENT_STATUS_AND_MASK(hwcpu));
 559
 560         /* Mask the DFS done interrupt, since we are going to poll */
 561         reg = readl(pmsu_mp_base + PMSU_EVENT_STATUS_AND_MASK(hwcpu));
 562         reg |= PMSU_EVENT_STATUS_AND_MASK_DFS_DONE_MASK;
 563         writel(reg, pmsu_mp_base + PMSU_EVENT_STATUS_AND_MASK(hwcpu));
 564
 565         /* Trigger the DFS on the appropriate CPU */
 566         smp_call_function_single(cpu, mvebu_pmsu_dfs_request_local,
 567                                  NULL, false);
 568
 569         /* Poll until the DFS done event is generated */
 570         timeout = jiffies + HZ;
 571         while (time_before(jiffies, timeout)) {
 572                 reg = readl(pmsu_mp_base + PMSU_EVENT_STATUS_AND_MASK(hwcpu));
 573                 if (reg & PMSU_EVENT_STATUS_AND_MASK_DFS_DONE)
 574                         break;
 575                 udelay(10);
 576         }
 577
 578         if (time_after(jiffies, timeout))
 579                 return -ETIME;
 580
 581         /* Restore the DFS mask to its original state */
 582         reg = readl(pmsu_mp_base + PMSU_EVENT_STATUS_AND_MASK(hwcpu));
 583         reg &= ~PMSU_EVENT_STATUS_AND_MASK_DFS_DONE_MASK;
 584         writel(reg, pmsu_mp_base + PMSU_EVENT_STATUS_AND_MASK(hwcpu));
 585
 586         return 0;
 587 }
 588
 589 struct cpufreq_dt_platform_data cpufreq_dt_pd = {
 590         .independent_clocks = true,
 591 };
 592
 593 static int __init armada_xp_pmsu_cpufreq_init(void)
 594 {
 595         struct device_node *np;
 596         struct resource res;
 597         int ret, cpu;
 598
 599         if (!of_machine_is_compatible("marvell,armadaxp"))
 600                 return 0;
 601
 602         /*
 603          * In order to have proper cpufreq handling, we need to ensure
 604          * that the Device Tree description of the CPU clock includes
 605          * the definition of the PMU DFS registers. If not, we do not
 606          * register the clock notifier and the cpufreq driver. This
 607          * piece of code is only for compatibility with old Device
 608          * Trees.
 609          */
 610         np = of_find_compatible_node(NULL, NULL, "marvell,armada-xp-cpu-clock");
 611         if (!np)
 612                 return 0;
 613
 614         ret = of_address_to_resource(np, 1, &res);
 615         if (ret) {
 616                 pr_warn(FW_WARN "not enabling cpufreq, deprecated armada-xp-cpu-clock binding\n");
 617                 of_node_put(np);
 618                 return 0;
 619         }
 620
 621         of_node_put(np);
 622
 623         /*
 624          * For each CPU, this loop registers the operating points
 625          * supported (which are the nominal CPU frequency and half of
 626          * it), and registers the clock notifier that will take care
 627          * of doing the PMSU part of a frequency transition.
 628          */
 629         for_each_possible_cpu(cpu) {
 630                 struct device *cpu_dev;
 631                 struct clk *clk;
 632                 int ret;
 633
 634                 cpu_dev = get_cpu_device(cpu);
 635                 if (!cpu_dev) {
 636                         pr_err("Cannot get CPU %d\n", cpu);
 637                         continue;
 638                 }
 639
 640                 clk = clk_get(cpu_dev, 0);
 641                 if (IS_ERR(clk)) {
 642                         pr_err("Cannot get clock for CPU %d\n", cpu);
 643                         return PTR_ERR(clk);
 644                 }
 645
 646                 /*
 647                  * In case of a failure of dev_pm_opp_add(), we don't
 648                  * bother with cleaning up the registered OPP (there's
 649                  * no function to do so), and simply cancel the
 650                  * registration of the cpufreq device.
 651                  */
 652                 ret = dev_pm_opp_add(cpu_dev, clk_get_rate(clk), 0);
 653                 if (ret) {
 654                         clk_put(clk);
 655                         return ret;
 656                 }
 657
 658                 ret = dev_pm_opp_add(cpu_dev, clk_get_rate(clk) / 2, 0);
 659                 if (ret) {
 660                         clk_put(clk);
 661                         return ret;
 662                 }
 663         }
 664
 665         platform_device_register_data(NULL, "cpufreq-dt", -1,
 666                                       &cpufreq_dt_pd, sizeof(cpufreq_dt_pd));
 667         return 0;
 668 }
 669
 670 device_initcall(armada_xp_pmsu_cpufreq_init);