root/drivers/soc/renesas/rcar-sysc.c

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DEFINITIONS

This source file includes following definitions.
  1. rcar_sysc_pwr_on_off
  2. rcar_sysc_power
  3. rcar_sysc_power_is_off
  4. to_rcar_pd
  5. rcar_sysc_pd_power_off
  6. rcar_sysc_pd_power_on
  7. rcar_sysc_pd_setup
  8. rcar_sysc_pd_init
  9. rcar_sysc_nullify
  10. rcar_sysc_power_cpu
  11. rcar_sysc_power_down_cpu
  12. rcar_sysc_power_up_cpu

   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 
  58 struct rcar_sysc_ch {
  59         u16 chan_offs;
  60         u8 chan_bit;
  61         u8 isr_bit;
  62 };
  63 
  64 static void __iomem *rcar_sysc_base;
  65 static DEFINE_SPINLOCK(rcar_sysc_lock); /* SMP CPUs + I/O devices */
  66 
  67 static 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 
  97 static 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 
 158 static 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 
 169 struct rcar_sysc_pd {
 170         struct generic_pm_domain genpd;
 171         struct rcar_sysc_ch ch;
 172         unsigned int flags;
 173         char name[];
 174 };
 175 
 176 static 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 
 181 static 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 
 189 static 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 
 197 static bool has_cpg_mstp;
 198 
 199 static 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 
 255 finalize:
 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 
 263 static 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 
 322 struct rcar_pm_domains {
 323         struct genpd_onecell_data onecell_data;
 324         struct generic_pm_domain *domains[RCAR_PD_ALWAYS_ON + 1];
 325 };
 326 
 327 static struct genpd_onecell_data *rcar_sysc_onecell_data;
 328 
 329 static 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 
 415 out_put:
 416         of_node_put(np);
 417         return error;
 418 }
 419 early_initcall(rcar_sysc_pd_init);
 420 
 421 void __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
 434 static 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 
 458 int rcar_sysc_power_down_cpu(unsigned int cpu)
 459 {
 460         return rcar_sysc_power_cpu(cpu, false);
 461 }
 462 
 463 int rcar_sysc_power_up_cpu(unsigned int cpu)
 464 {
 465         return rcar_sysc_power_cpu(cpu, true);
 466 }
 467 #endif /* CONFIG_ARCH_R8A7779 */

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