arch/arm/mach-shmobile/pm-rmobile.c

   1 /*
   2  * rmobile power management support
   3  *
   4  * Copyright (C) 2012  Renesas Solutions Corp.
   5  * Copyright (C) 2012  Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
   6  * Copyright (C) 2014  Glider bvba
   7  *
   8  * based on pm-sh7372.c
   9  *  Copyright (C) 2011 Magnus Damm
  10  *
  11  * This file is subject to the terms and conditions of the GNU General Public
  12  * License.  See the file "COPYING" in the main directory of this archive
  13  * for more details.
  14  */
  15 #include <linux/console.h>
  16 #include <linux/delay.h>
  17 #include <linux/of.h>
  18 #include <linux/of_address.h>
  19 #include <linux/of_platform.h>
  20 #include <linux/platform_device.h>
  21 #include <linux/pm.h>
  22 #include <linux/pm_clock.h>
  23 #include <linux/slab.h>
  24
  25 #include <asm/io.h>
  26
  27 #include "pm-rmobile.h"
  28
  29 /* SYSC */
  30 #define SPDCR           0x08    /* SYS Power Down Control Register */
  31 #define SWUCR           0x14    /* SYS Wakeup Control Register */
  32 #define PSTR            0x80    /* Power Status Register */
  33
  34 #define PSTR_RETRIES    100
  35 #define PSTR_DELAY_US   10
  36
  37 static inline
  38 struct rmobile_pm_domain *to_rmobile_pd(struct generic_pm_domain *d)
  39 {
  40         return container_of(d, struct rmobile_pm_domain, genpd);
  41 }
  42
  43 static int rmobile_pd_power_down(struct generic_pm_domain *genpd)
  44 {
  45         struct rmobile_pm_domain *rmobile_pd = to_rmobile_pd(genpd);
  46         unsigned int mask;
  47
  48         if (rmobile_pd->bit_shift == ~0)
  49                 return -EBUSY;
  50
  51         mask = BIT(rmobile_pd->bit_shift);
  52         if (rmobile_pd->suspend) {
  53                 int ret = rmobile_pd->suspend();
  54
  55                 if (ret)
  56                         return ret;
  57         }
  58
  59         if (__raw_readl(rmobile_pd->base + PSTR) & mask) {
  60                 unsigned int retry_count;
  61                 __raw_writel(mask, rmobile_pd->base + SPDCR);
  62
  63                 for (retry_count = PSTR_RETRIES; retry_count; retry_count--) {
  64                         if (!(__raw_readl(rmobile_pd->base + SPDCR) & mask))
  65                                 break;
  66                         cpu_relax();
  67                 }
  68         }
  69
  70         if (!rmobile_pd->no_debug)
  71                 pr_debug("%s: Power off, 0x%08x -> PSTR = 0x%08x\n",
  72                          genpd->name, mask,
  73                          __raw_readl(rmobile_pd->base + PSTR));
  74
  75         return 0;
  76 }
  77
  78 static int __rmobile_pd_power_up(struct rmobile_pm_domain *rmobile_pd,
  79                                  bool do_resume)
  80 {
  81         unsigned int mask;
  82         unsigned int retry_count;
  83         int ret = 0;
  84
  85         if (rmobile_pd->bit_shift == ~0)
  86                 return 0;
  87
  88         mask = BIT(rmobile_pd->bit_shift);
  89         if (__raw_readl(rmobile_pd->base + PSTR) & mask)
  90                 goto out;
  91
  92         __raw_writel(mask, rmobile_pd->base + SWUCR);
  93
  94         for (retry_count = 2 * PSTR_RETRIES; retry_count; retry_count--) {
  95                 if (!(__raw_readl(rmobile_pd->base + SWUCR) & mask))
  96                         break;
  97                 if (retry_count > PSTR_RETRIES)
  98                         udelay(PSTR_DELAY_US);
  99                 else
 100                         cpu_relax();
 101         }
 102         if (!retry_count)
 103                 ret = -EIO;
 104
 105         if (!rmobile_pd->no_debug)
 106                 pr_debug("%s: Power on, 0x%08x -> PSTR = 0x%08x\n",
 107                          rmobile_pd->genpd.name, mask,
 108                          __raw_readl(rmobile_pd->base + PSTR));
 109
 110 out:
 111         if (ret == 0 && rmobile_pd->resume && do_resume)
 112                 rmobile_pd->resume();
 113
 114         return ret;
 115 }
 116
 117 static int rmobile_pd_power_up(struct generic_pm_domain *genpd)
 118 {
 119         return __rmobile_pd_power_up(to_rmobile_pd(genpd), true);
 120 }
 121
 122 static bool rmobile_pd_active_wakeup(struct device *dev)
 123 {
 124         return true;
 125 }
 126
 127 static int rmobile_pd_attach_dev(struct generic_pm_domain *domain,
 128                                  struct device *dev)
 129 {
 130         int error;
 131
 132         error = pm_clk_create(dev);
 133         if (error) {
 134                 dev_err(dev, "pm_clk_create failed %d\n", error);
 135                 return error;
 136         }
 137
 138         error = pm_clk_add(dev, NULL);
 139         if (error) {
 140                 dev_err(dev, "pm_clk_add failed %d\n", error);
 141                 goto fail;
 142         }
 143
 144         return 0;
 145
 146 fail:
 147         pm_clk_destroy(dev);
 148         return error;
 149 }
 150
 151 static void rmobile_pd_detach_dev(struct generic_pm_domain *domain,
 152                                   struct device *dev)
 153 {
 154         pm_clk_destroy(dev);
 155 }
 156
 157 static void rmobile_init_pm_domain(struct rmobile_pm_domain *rmobile_pd)
 158 {
 159         struct generic_pm_domain *genpd = &rmobile_pd->genpd;
 160         struct dev_power_governor *gov = rmobile_pd->gov;
 161
 162         genpd->flags = GENPD_FLAG_PM_CLK;
 163         pm_genpd_init(genpd, gov ? : &simple_qos_governor, false);
 164         genpd->dev_ops.active_wakeup    = rmobile_pd_active_wakeup;
 165         genpd->power_off                = rmobile_pd_power_down;
 166         genpd->power_on                 = rmobile_pd_power_up;
 167         genpd->attach_dev               = rmobile_pd_attach_dev;
 168         genpd->detach_dev               = rmobile_pd_detach_dev;
 169         __rmobile_pd_power_up(rmobile_pd, false);
 170 }
 171
 172 #ifdef CONFIG_ARCH_SHMOBILE_LEGACY
 173
 174 void rmobile_init_domains(struct rmobile_pm_domain domains[], int num)
 175 {
 176         int j;
 177
 178         for (j = 0; j < num; j++)
 179                 rmobile_init_pm_domain(&domains[j]);
 180 }
 181
 182 void rmobile_add_device_to_domain_td(const char *domain_name,
 183                                      struct platform_device *pdev,
 184                                      struct gpd_timing_data *td)
 185 {
 186         struct device *dev = &pdev->dev;
 187
 188         __pm_genpd_name_add_device(domain_name, dev, td);
 189 }
 190
 191 void rmobile_add_devices_to_domains(struct pm_domain_device data[],
 192                                     int size)
 193 {
 194         struct gpd_timing_data latencies = {
 195                 .stop_latency_ns = DEFAULT_DEV_LATENCY_NS,
 196                 .start_latency_ns = DEFAULT_DEV_LATENCY_NS,
 197                 .save_state_latency_ns = DEFAULT_DEV_LATENCY_NS,
 198                 .restore_state_latency_ns = DEFAULT_DEV_LATENCY_NS,
 199         };
 200         int j;
 201
 202         for (j = 0; j < size; j++)
 203                 rmobile_add_device_to_domain_td(data[j].domain_name,
 204                                                 data[j].pdev, &latencies);
 205 }
 206
 207 #else /* !CONFIG_ARCH_SHMOBILE_LEGACY */
 208
 209 static int rmobile_pd_suspend_busy(void)
 210 {
 211         /*
 212          * This domain should not be turned off.
 213          */
 214         return -EBUSY;
 215 }
 216
 217 static int rmobile_pd_suspend_console(void)
 218 {
 219         /*
 220          * Serial consoles make use of SCIF hardware located in this domain,
 221          * hence keep the power domain on if "no_console_suspend" is set.
 222          */
 223         return console_suspend_enabled ? 0 : -EBUSY;
 224 }
 225
 226 enum pd_types {
 227         PD_NORMAL,
 228         PD_CPU,
 229         PD_CONSOLE,
 230         PD_DEBUG,
 231         PD_MEMCTL,
 232 };
 233
 234 #define MAX_NUM_SPECIAL_PDS     16
 235
 236 static struct special_pd {
 237         struct device_node *pd;
 238         enum pd_types type;
 239 } special_pds[MAX_NUM_SPECIAL_PDS] __initdata;
 240
 241 static unsigned int num_special_pds __initdata;
 242
 243 static const struct of_device_id special_ids[] __initconst = {
 244         { .compatible = "arm,coresight-etm3x", .data = (void *)PD_DEBUG },
 245         { .compatible = "renesas,dbsc-r8a73a4", .data = (void *)PD_MEMCTL, },
 246         { .compatible = "renesas,dbsc3-r8a7740", .data = (void *)PD_MEMCTL, },
 247         { .compatible = "renesas,sbsc-sh73a0", .data = (void *)PD_MEMCTL, },
 248         { /* sentinel */ },
 249 };
 250
 251 static void __init add_special_pd(struct device_node *np, enum pd_types type)
 252 {
 253         unsigned int i;
 254         struct device_node *pd;
 255
 256         pd = of_parse_phandle(np, "power-domains", 0);
 257         if (!pd)
 258                 return;
 259
 260         for (i = 0; i < num_special_pds; i++)
 261                 if (pd == special_pds[i].pd && type == special_pds[i].type) {
 262                         of_node_put(pd);
 263                         return;
 264                 }
 265
 266         if (num_special_pds == ARRAY_SIZE(special_pds)) {
 267                 pr_warn("Too many special PM domains\n");
 268                 of_node_put(pd);
 269                 return;
 270         }
 271
 272         pr_debug("Special PM domain %s type %d for %s\n", pd->name, type,
 273                  np->full_name);
 274
 275         special_pds[num_special_pds].pd = pd;
 276         special_pds[num_special_pds].type = type;
 277         num_special_pds++;
 278 }
 279
 280 static void __init get_special_pds(void)
 281 {
 282         struct device_node *np;
 283         const struct of_device_id *id;
 284
 285         /* PM domains containing CPUs */
 286         for_each_node_by_type(np, "cpu")
 287                 add_special_pd(np, PD_CPU);
 288
 289         /* PM domain containing console */
 290         if (of_stdout)
 291                 add_special_pd(of_stdout, PD_CONSOLE);
 292
 293         /* PM domains containing other special devices */
 294         for_each_matching_node_and_match(np, special_ids, &id)
 295                 add_special_pd(np, (enum pd_types)id->data);
 296 }
 297
 298 static void __init put_special_pds(void)
 299 {
 300         unsigned int i;
 301
 302         for (i = 0; i < num_special_pds; i++)
 303                 of_node_put(special_pds[i].pd);
 304 }
 305
 306 static enum pd_types __init pd_type(const struct device_node *pd)
 307 {
 308         unsigned int i;
 309
 310         for (i = 0; i < num_special_pds; i++)
 311                 if (pd == special_pds[i].pd)
 312                         return special_pds[i].type;
 313
 314         return PD_NORMAL;
 315 }
 316
 317 static void __init rmobile_setup_pm_domain(struct device_node *np,
 318                                            struct rmobile_pm_domain *pd)
 319 {
 320         const char *name = pd->genpd.name;
 321
 322         switch (pd_type(np)) {
 323         case PD_CPU:
 324                 /*
 325                  * This domain contains the CPU core and therefore it should
 326                  * only be turned off if the CPU is not in use.
 327                  */
 328                 pr_debug("PM domain %s contains CPU\n", name);
 329                 pd->gov = &pm_domain_always_on_gov;
 330                 pd->suspend = rmobile_pd_suspend_busy;
 331                 break;
 332
 333         case PD_CONSOLE:
 334                 pr_debug("PM domain %s contains serial console\n", name);
 335                 pd->gov = &pm_domain_always_on_gov;
 336                 pd->suspend = rmobile_pd_suspend_console;
 337                 break;
 338
 339         case PD_DEBUG:
 340                 /*
 341                  * This domain contains the Coresight-ETM hardware block and
 342                  * therefore it should only be turned off if the debug module
 343                  * is not in use.
 344                  */
 345                 pr_debug("PM domain %s contains Coresight-ETM\n", name);
 346                 pd->gov = &pm_domain_always_on_gov;
 347                 pd->suspend = rmobile_pd_suspend_busy;
 348                 break;
 349
 350         case PD_MEMCTL:
 351                 /*
 352                  * This domain contains a memory-controller and therefore it
 353                  * should only be turned off if memory is not in use.
 354                  */
 355                 pr_debug("PM domain %s contains MEMCTL\n", name);
 356                 pd->gov = &pm_domain_always_on_gov;
 357                 pd->suspend = rmobile_pd_suspend_busy;
 358                 break;
 359
 360         case PD_NORMAL:
 361                 break;
 362         }
 363
 364         rmobile_init_pm_domain(pd);
 365 }
 366
 367 static int __init rmobile_add_pm_domains(void __iomem *base,
 368                                          struct device_node *parent,
 369                                          struct generic_pm_domain *genpd_parent)
 370 {
 371         struct device_node *np;
 372
 373         for_each_child_of_node(parent, np) {
 374                 struct rmobile_pm_domain *pd;
 375                 u32 idx = ~0;
 376
 377                 if (of_property_read_u32(np, "reg", &idx)) {
 378                         /* always-on domain */
 379                 }
 380
 381                 pd = kzalloc(sizeof(*pd), GFP_KERNEL);
 382                 if (!pd)
 383                         return -ENOMEM;
 384
 385                 pd->genpd.name = np->name;
 386                 pd->base = base;
 387                 pd->bit_shift = idx;
 388
 389                 rmobile_setup_pm_domain(np, pd);
 390                 if (genpd_parent)
 391                         pm_genpd_add_subdomain(genpd_parent, &pd->genpd);
 392                 of_genpd_add_provider_simple(np, &pd->genpd);
 393
 394                 rmobile_add_pm_domains(base, np, &pd->genpd);
 395         }
 396         return 0;
 397 }
 398
 399 static int __init rmobile_init_pm_domains(void)
 400 {
 401         struct device_node *np, *pmd;
 402         bool scanned = false;
 403         void __iomem *base;
 404         int ret = 0;
 405
 406         for_each_compatible_node(np, NULL, "renesas,sysc-rmobile") {
 407                 base = of_iomap(np, 0);
 408                 if (!base) {
 409                         pr_warn("%s cannot map reg 0\n", np->full_name);
 410                         continue;
 411                 }
 412
 413                 pmd = of_get_child_by_name(np, "pm-domains");
 414                 if (!pmd) {
 415                         pr_warn("%s lacks pm-domains node\n", np->full_name);
 416                         continue;
 417                 }
 418
 419                 if (!scanned) {
 420                         /* Find PM domains containing special blocks */
 421                         get_special_pds();
 422                         scanned = true;
 423                 }
 424
 425                 ret = rmobile_add_pm_domains(base, pmd, NULL);
 426                 of_node_put(pmd);
 427                 if (ret) {
 428                         of_node_put(np);
 429                         break;
 430                 }
 431         }
 432
 433         put_special_pds();
 434
 435         return ret;
 436 }
 437
 438 core_initcall(rmobile_init_pm_domains);
 439
 440 #endif /* !CONFIG_ARCH_SHMOBILE_LEGACY */