linux/drivers/soc/renesas/rcar-sysc.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * R-Car SYSC Power management support
   4 *
   5 * Copyright (C) 2014  Magnus Damm
   6 * Copyright (C) 2015-2017 Glider bvba
   7 */
   8
   9#include <linux/clk/renesas.h>
  10#include <linux/delay.h>
  11#include <linux/err.h>
  12#include <linux/mm.h>
  13#include <linux/of_address.h>
  14#include <linux/pm_domain.h>
  15#include <linux/slab.h>
  16#include <linux/spinlock.h>
  17#include <linux/io.h>
  18#include <linux/soc/renesas/rcar-sysc.h>
  19
  20#include "rcar-sysc.h"
  21
  22/* SYSC Common */
  23#define SYSCSR                  0x00    /* SYSC Status Register */
  24#define SYSCISR                 0x04    /* Interrupt Status Register */
  25#define SYSCISCR                0x08    /* Interrupt Status Clear Register */
  26#define SYSCIER                 0x0c    /* Interrupt Enable Register */
  27#define SYSCIMR                 0x10    /* Interrupt Mask Register */
  28
  29/* SYSC Status Register */
  30#define SYSCSR_PONENB           1       /* Ready for power resume requests */
  31#define SYSCSR_POFFENB          0       /* Ready for power shutoff requests */
  32
  33/*
  34 * Power Control Register Offsets inside the register block for each domain
  35 * Note: The "CR" registers for ARM cores exist on H1 only
  36 *       Use WFI to power off, CPG/APMU to resume ARM cores on R-Car Gen2
  37 *       Use PSCI on R-Car Gen3
  38 */
  39#define PWRSR_OFFS              0x00    /* Power Status Register */
  40#define PWROFFCR_OFFS           0x04    /* Power Shutoff Control Register */
  41#define PWROFFSR_OFFS           0x08    /* Power Shutoff Status Register */
  42#define PWRONCR_OFFS            0x0c    /* Power Resume Control Register */
  43#define PWRONSR_OFFS            0x10    /* Power Resume Status Register */
  44#define PWRER_OFFS              0x14    /* Power Shutoff/Resume Error */
  45
  46
  47#define SYSCSR_RETRIES          100
  48#define SYSCSR_DELAY_US         1
  49
  50#define PWRER_RETRIES           100
  51#define PWRER_DELAY_US          1
  52
  53#define SYSCISR_RETRIES         1000
  54#define SYSCISR_DELAY_US        1
  55
  56#define RCAR_PD_ALWAYS_ON       32      /* Always-on power area */
  57
  58struct rcar_sysc_ch {
  59        u16 chan_offs;
  60        u8 chan_bit;
  61        u8 isr_bit;
  62};
  63
  64static void __iomem *rcar_sysc_base;
  65static DEFINE_SPINLOCK(rcar_sysc_lock); /* SMP CPUs + I/O devices */
  66
  67static int rcar_sysc_pwr_on_off(const struct rcar_sysc_ch *sysc_ch, bool on)
  68{
  69        unsigned int sr_bit, reg_offs;
  70        int k;
  71
  72        if (on) {
  73                sr_bit = SYSCSR_PONENB;
  74                reg_offs = PWRONCR_OFFS;
  75        } else {
  76                sr_bit = SYSCSR_POFFENB;
  77                reg_offs = PWROFFCR_OFFS;
  78        }
  79
  80        /* Wait until SYSC is ready to accept a power request */
  81        for (k = 0; k < SYSCSR_RETRIES; k++) {
  82                if (ioread32(rcar_sysc_base + SYSCSR) & BIT(sr_bit))
  83                        break;
  84                udelay(SYSCSR_DELAY_US);
  85        }
  86
  87        if (k == SYSCSR_RETRIES)
  88                return -EAGAIN;
  89
  90        /* Submit power shutoff or power resume request */
  91        iowrite32(BIT(sysc_ch->chan_bit),
  92                  rcar_sysc_base + sysc_ch->chan_offs + reg_offs);
  93
  94        return 0;
  95}
  96
  97static int rcar_sysc_power(const struct rcar_sysc_ch *sysc_ch, bool on)
  98{
  99        unsigned int isr_mask = BIT(sysc_ch->isr_bit);
 100        unsigned int chan_mask = BIT(sysc_ch->chan_bit);
 101        unsigned int status;
 102        unsigned long flags;
 103        int ret = 0;
 104        int k;
 105
 106        spin_lock_irqsave(&rcar_sysc_lock, flags);
 107
 108        /*
 109         * The interrupt source needs to be enabled, but masked, to prevent the
 110         * CPU from receiving it.
 111         */
 112        iowrite32(ioread32(rcar_sysc_base + SYSCIMR) | isr_mask,
 113                  rcar_sysc_base + SYSCIMR);
 114        iowrite32(ioread32(rcar_sysc_base + SYSCIER) | isr_mask,
 115                  rcar_sysc_base + SYSCIER);
 116
 117        iowrite32(isr_mask, rcar_sysc_base + SYSCISCR);
 118
 119        /* Submit power shutoff or resume request until it was accepted */
 120        for (k = 0; k < PWRER_RETRIES; k++) {
 121                ret = rcar_sysc_pwr_on_off(sysc_ch, on);
 122                if (ret)
 123                        goto out;
 124
 125                status = ioread32(rcar_sysc_base +
 126                                  sysc_ch->chan_offs + PWRER_OFFS);
 127                if (!(status & chan_mask))
 128                        break;
 129
 130                udelay(PWRER_DELAY_US);
 131        }
 132
 133        if (k == PWRER_RETRIES) {
 134                ret = -EIO;
 135                goto out;
 136        }
 137
 138        /* Wait until the power shutoff or resume request has completed * */
 139        for (k = 0; k < SYSCISR_RETRIES; k++) {
 140                if (ioread32(rcar_sysc_base + SYSCISR) & isr_mask)
 141                        break;
 142                udelay(SYSCISR_DELAY_US);
 143        }
 144
 145        if (k == SYSCISR_RETRIES)
 146                ret = -EIO;
 147
 148        iowrite32(isr_mask, rcar_sysc_base + SYSCISCR);
 149
 150 out:
 151        spin_unlock_irqrestore(&rcar_sysc_lock, flags);
 152
 153        pr_debug("sysc power %s domain %d: %08x -> %d\n", on ? "on" : "off",
 154                 sysc_ch->isr_bit, ioread32(rcar_sysc_base + SYSCISR), ret);
 155        return ret;
 156}
 157
 158static bool rcar_sysc_power_is_off(const struct rcar_sysc_ch *sysc_ch)
 159{
 160        unsigned int st;
 161
 162        st = ioread32(rcar_sysc_base + sysc_ch->chan_offs + PWRSR_OFFS);
 163        if (st & BIT(sysc_ch->chan_bit))
 164                return true;
 165
 166        return false;
 167}
 168
 169struct rcar_sysc_pd {
 170        struct generic_pm_domain genpd;
 171        struct rcar_sysc_ch ch;
 172        unsigned int flags;
 173        char name[];
 174};
 175
 176static inline struct rcar_sysc_pd *to_rcar_pd(struct generic_pm_domain *d)
 177{
 178        return container_of(d, struct rcar_sysc_pd, genpd);
 179}
 180
 181static int rcar_sysc_pd_power_off(struct generic_pm_domain *genpd)
 182{
 183        struct rcar_sysc_pd *pd = to_rcar_pd(genpd);
 184
 185        pr_debug("%s: %s\n", __func__, genpd->name);
 186        return rcar_sysc_power(&pd->ch, false);
 187}
 188
 189static int rcar_sysc_pd_power_on(struct generic_pm_domain *genpd)
 190{
 191        struct rcar_sysc_pd *pd = to_rcar_pd(genpd);
 192
 193        pr_debug("%s: %s\n", __func__, genpd->name);
 194        return rcar_sysc_power(&pd->ch, true);
 195}
 196
 197static bool has_cpg_mstp;
 198
 199static int __init rcar_sysc_pd_setup(struct rcar_sysc_pd *pd)
 200{
 201        struct generic_pm_domain *genpd = &pd->genpd;
 202        const char *name = pd->genpd.name;
 203        int error;
 204
 205        if (pd->flags & PD_CPU) {
 206                /*
 207                 * This domain contains a CPU core and therefore it should
 208                 * only be turned off if the CPU is not in use.
 209                 */
 210                pr_debug("PM domain %s contains %s\n", name, "CPU");
 211                genpd->flags |= GENPD_FLAG_ALWAYS_ON;
 212        } else if (pd->flags & PD_SCU) {
 213                /*
 214                 * This domain contains an SCU and cache-controller, and
 215                 * therefore it should only be turned off if the CPU cores are
 216                 * not in use.
 217                 */
 218                pr_debug("PM domain %s contains %s\n", name, "SCU");
 219                genpd->flags |= GENPD_FLAG_ALWAYS_ON;
 220        } else if (pd->flags & PD_NO_CR) {
 221                /*
 222                 * This domain cannot be turned off.
 223                 */
 224                genpd->flags |= GENPD_FLAG_ALWAYS_ON;
 225        }
 226
 227        if (!(pd->flags & (PD_CPU | PD_SCU))) {
 228                /* Enable Clock Domain for I/O devices */
 229                genpd->flags |= GENPD_FLAG_PM_CLK | GENPD_FLAG_ACTIVE_WAKEUP;
 230                if (has_cpg_mstp) {
 231                        genpd->attach_dev = cpg_mstp_attach_dev;
 232                        genpd->detach_dev = cpg_mstp_detach_dev;
 233                } else {
 234                        genpd->attach_dev = cpg_mssr_attach_dev;
 235                        genpd->detach_dev = cpg_mssr_detach_dev;
 236                }
 237        }
 238
 239        genpd->power_off = rcar_sysc_pd_power_off;
 240        genpd->power_on = rcar_sysc_pd_power_on;
 241
 242        if (pd->flags & (PD_CPU | PD_NO_CR)) {
 243                /* Skip CPUs (handled by SMP code) and areas without control */
 244                pr_debug("%s: Not touching %s\n", __func__, genpd->name);
 245                goto finalize;
 246        }
 247
 248        if (!rcar_sysc_power_is_off(&pd->ch)) {
 249                pr_debug("%s: %s is already powered\n", __func__, genpd->name);
 250                goto finalize;
 251        }
 252
 253        rcar_sysc_power(&pd->ch, true);
 254
 255finalize:
 256        error = pm_genpd_init(genpd, &simple_qos_governor, false);
 257        if (error)
 258                pr_err("Failed to init PM domain %s: %d\n", name, error);
 259
 260        return error;
 261}
 262
 263static const struct of_device_id rcar_sysc_matches[] __initconst = {
 264#ifdef CONFIG_SYSC_R8A7743
 265        { .compatible = "renesas,r8a7743-sysc", .data = &r8a7743_sysc_info },
 266        /* RZ/G1N is identical to RZ/G2M w.r.t. power domains. */
 267        { .compatible = "renesas,r8a7744-sysc", .data = &r8a7743_sysc_info },
 268#endif
 269#ifdef CONFIG_SYSC_R8A7745
 270        { .compatible = "renesas,r8a7745-sysc", .data = &r8a7745_sysc_info },
 271#endif
 272#ifdef CONFIG_SYSC_R8A77470
 273        { .compatible = "renesas,r8a77470-sysc", .data = &r8a77470_sysc_info },
 274#endif
 275#ifdef CONFIG_SYSC_R8A774A1
 276        { .compatible = "renesas,r8a774a1-sysc", .data = &r8a774a1_sysc_info },
 277#endif
 278#ifdef CONFIG_SYSC_R8A774C0
 279        { .compatible = "renesas,r8a774c0-sysc", .data = &r8a774c0_sysc_info },
 280#endif
 281#ifdef CONFIG_SYSC_R8A7779
 282        { .compatible = "renesas,r8a7779-sysc", .data = &r8a7779_sysc_info },
 283#endif
 284#ifdef CONFIG_SYSC_R8A7790
 285        { .compatible = "renesas,r8a7790-sysc", .data = &r8a7790_sysc_info },
 286#endif
 287#ifdef CONFIG_SYSC_R8A7791
 288        { .compatible = "renesas,r8a7791-sysc", .data = &r8a7791_sysc_info },
 289        /* R-Car M2-N is identical to R-Car M2-W w.r.t. power domains. */
 290        { .compatible = "renesas,r8a7793-sysc", .data = &r8a7791_sysc_info },
 291#endif
 292#ifdef CONFIG_SYSC_R8A7792
 293        { .compatible = "renesas,r8a7792-sysc", .data = &r8a7792_sysc_info },
 294#endif
 295#ifdef CONFIG_SYSC_R8A7794
 296        { .compatible = "renesas,r8a7794-sysc", .data = &r8a7794_sysc_info },
 297#endif
 298#ifdef CONFIG_SYSC_R8A7795
 299        { .compatible = "renesas,r8a7795-sysc", .data = &r8a7795_sysc_info },
 300#endif
 301#ifdef CONFIG_SYSC_R8A7796
 302        { .compatible = "renesas,r8a7796-sysc", .data = &r8a7796_sysc_info },
 303#endif
 304#ifdef CONFIG_SYSC_R8A77965
 305        { .compatible = "renesas,r8a77965-sysc", .data = &r8a77965_sysc_info },
 306#endif
 307#ifdef CONFIG_SYSC_R8A77970
 308        { .compatible = "renesas,r8a77970-sysc", .data = &r8a77970_sysc_info },
 309#endif
 310#ifdef CONFIG_SYSC_R8A77980
 311        { .compatible = "renesas,r8a77980-sysc", .data = &r8a77980_sysc_info },
 312#endif
 313#ifdef CONFIG_SYSC_R8A77990
 314        { .compatible = "renesas,r8a77990-sysc", .data = &r8a77990_sysc_info },
 315#endif
 316#ifdef CONFIG_SYSC_R8A77995
 317        { .compatible = "renesas,r8a77995-sysc", .data = &r8a77995_sysc_info },
 318#endif
 319        { /* sentinel */ }
 320};
 321
 322struct rcar_pm_domains {
 323        struct genpd_onecell_data onecell_data;
 324        struct generic_pm_domain *domains[RCAR_PD_ALWAYS_ON + 1];
 325};
 326
 327static struct genpd_onecell_data *rcar_sysc_onecell_data;
 328
 329static int __init rcar_sysc_pd_init(void)
 330{
 331        const struct rcar_sysc_info *info;
 332        const struct of_device_id *match;
 333        struct rcar_pm_domains *domains;
 334        struct device_node *np;
 335        void __iomem *base;
 336        unsigned int i;
 337        int error;
 338
 339        np = of_find_matching_node_and_match(NULL, rcar_sysc_matches, &match);
 340        if (!np)
 341                return -ENODEV;
 342
 343        info = match->data;
 344
 345        if (info->init) {
 346                error = info->init();
 347                if (error)
 348                        goto out_put;
 349        }
 350
 351        has_cpg_mstp = of_find_compatible_node(NULL, NULL,
 352                                               "renesas,cpg-mstp-clocks");
 353
 354        base = of_iomap(np, 0);
 355        if (!base) {
 356                pr_warn("%pOF: Cannot map regs\n", np);
 357                error = -ENOMEM;
 358                goto out_put;
 359        }
 360
 361        rcar_sysc_base = base;
 362
 363        domains = kzalloc(sizeof(*domains), GFP_KERNEL);
 364        if (!domains) {
 365                error = -ENOMEM;
 366                goto out_put;
 367        }
 368
 369        domains->onecell_data.domains = domains->domains;
 370        domains->onecell_data.num_domains = ARRAY_SIZE(domains->domains);
 371        rcar_sysc_onecell_data = &domains->onecell_data;
 372
 373        for (i = 0; i < info->num_areas; i++) {
 374                const struct rcar_sysc_area *area = &info->areas[i];
 375                struct rcar_sysc_pd *pd;
 376
 377                if (!area->name) {
 378                        /* Skip NULLified area */
 379                        continue;
 380                }
 381
 382                pd = kzalloc(sizeof(*pd) + strlen(area->name) + 1, GFP_KERNEL);
 383                if (!pd) {
 384                        error = -ENOMEM;
 385                        goto out_put;
 386                }
 387
 388                strcpy(pd->name, area->name);
 389                pd->genpd.name = pd->name;
 390                pd->ch.chan_offs = area->chan_offs;
 391                pd->ch.chan_bit = area->chan_bit;
 392                pd->ch.isr_bit = area->isr_bit;
 393                pd->flags = area->flags;
 394
 395                error = rcar_sysc_pd_setup(pd);
 396                if (error)
 397                        goto out_put;
 398
 399                domains->domains[area->isr_bit] = &pd->genpd;
 400
 401                if (area->parent < 0)
 402                        continue;
 403
 404                error = pm_genpd_add_subdomain(domains->domains[area->parent],
 405                                               &pd->genpd);
 406                if (error) {
 407                        pr_warn("Failed to add PM subdomain %s to parent %u\n",
 408                                area->name, area->parent);
 409                        goto out_put;
 410                }
 411        }
 412
 413        error = of_genpd_add_provider_onecell(np, &domains->onecell_data);
 414
 415out_put:
 416        of_node_put(np);
 417        return error;
 418}
 419early_initcall(rcar_sysc_pd_init);
 420
 421void __init rcar_sysc_nullify(struct rcar_sysc_area *areas,
 422                              unsigned int num_areas, u8 id)
 423{
 424        unsigned int i;
 425
 426        for (i = 0; i < num_areas; i++)
 427                if (areas[i].isr_bit == id) {
 428                        areas[i].name = NULL;
 429                        return;
 430                }
 431}
 432
 433#ifdef CONFIG_ARCH_R8A7779
 434static int rcar_sysc_power_cpu(unsigned int idx, bool on)
 435{
 436        struct generic_pm_domain *genpd;
 437        struct rcar_sysc_pd *pd;
 438        unsigned int i;
 439
 440        if (!rcar_sysc_onecell_data)
 441                return -ENODEV;
 442
 443        for (i = 0; i < rcar_sysc_onecell_data->num_domains; i++) {
 444                genpd = rcar_sysc_onecell_data->domains[i];
 445                if (!genpd)
 446                        continue;
 447
 448                pd = to_rcar_pd(genpd);
 449                if (!(pd->flags & PD_CPU) || pd->ch.chan_bit != idx)
 450                        continue;
 451
 452                return rcar_sysc_power(&pd->ch, on);
 453        }
 454
 455        return -ENOENT;
 456}
 457
 458int rcar_sysc_power_down_cpu(unsigned int cpu)
 459{
 460        return rcar_sysc_power_cpu(cpu, false);
 461}
 462
 463int rcar_sysc_power_up_cpu(unsigned int cpu)
 464{
 465        return rcar_sysc_power_cpu(cpu, true);
 466}
 467#endif /* CONFIG_ARCH_R8A7779 */
 468