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 static int rmobile_pd_suspend_busy(void)
 173 {
 174         /*
 175          * This domain should not be turned off.
 176          */
 177         return -EBUSY;
 178 }
 179
 180 static int rmobile_pd_suspend_console(void)
 181 {
 182         /*
 183          * Serial consoles make use of SCIF hardware located in this domain,
 184          * hence keep the power domain on if "no_console_suspend" is set.
 185          */
 186         return console_suspend_enabled ? 0 : -EBUSY;
 187 }
 188
 189 enum pd_types {
 190         PD_NORMAL,
 191         PD_CPU,
 192         PD_CONSOLE,
 193         PD_DEBUG,
 194         PD_MEMCTL,
 195 };
 196
 197 #define MAX_NUM_SPECIAL_PDS     16
 198
 199 static struct special_pd {
 200         struct device_node *pd;
 201         enum pd_types type;
 202 } special_pds[MAX_NUM_SPECIAL_PDS] __initdata;
 203
 204 static unsigned int num_special_pds __initdata;
 205
 206 static const struct of_device_id special_ids[] __initconst = {
 207         { .compatible = "arm,coresight-etm3x", .data = (void *)PD_DEBUG },
 208         { .compatible = "renesas,dbsc-r8a73a4", .data = (void *)PD_MEMCTL, },
 209         { .compatible = "renesas,dbsc3-r8a7740", .data = (void *)PD_MEMCTL, },
 210         { .compatible = "renesas,sbsc-sh73a0", .data = (void *)PD_MEMCTL, },
 211         { /* sentinel */ },
 212 };
 213
 214 static void __init add_special_pd(struct device_node *np, enum pd_types type)
 215 {
 216         unsigned int i;
 217         struct device_node *pd;
 218
 219         pd = of_parse_phandle(np, "power-domains", 0);
 220         if (!pd)
 221                 return;
 222
 223         for (i = 0; i < num_special_pds; i++)
 224                 if (pd == special_pds[i].pd && type == special_pds[i].type) {
 225                         of_node_put(pd);
 226                         return;
 227                 }
 228
 229         if (num_special_pds == ARRAY_SIZE(special_pds)) {
 230                 pr_warn("Too many special PM domains\n");
 231                 of_node_put(pd);
 232                 return;
 233         }
 234
 235         pr_debug("Special PM domain %s type %d for %s\n", pd->name, type,
 236                  np->full_name);
 237
 238         special_pds[num_special_pds].pd = pd;
 239         special_pds[num_special_pds].type = type;
 240         num_special_pds++;
 241 }
 242
 243 static void __init get_special_pds(void)
 244 {
 245         struct device_node *np;
 246         const struct of_device_id *id;
 247
 248         /* PM domains containing CPUs */
 249         for_each_node_by_type(np, "cpu")
 250                 add_special_pd(np, PD_CPU);
 251
 252         /* PM domain containing console */
 253         if (of_stdout)
 254                 add_special_pd(of_stdout, PD_CONSOLE);
 255
 256         /* PM domains containing other special devices */
 257         for_each_matching_node_and_match(np, special_ids, &id)
 258                 add_special_pd(np, (enum pd_types)id->data);
 259 }
 260
 261 static void __init put_special_pds(void)
 262 {
 263         unsigned int i;
 264
 265         for (i = 0; i < num_special_pds; i++)
 266                 of_node_put(special_pds[i].pd);
 267 }
 268
 269 static enum pd_types __init pd_type(const struct device_node *pd)
 270 {
 271         unsigned int i;
 272
 273         for (i = 0; i < num_special_pds; i++)
 274                 if (pd == special_pds[i].pd)
 275                         return special_pds[i].type;
 276
 277         return PD_NORMAL;
 278 }
 279
 280 static void __init rmobile_setup_pm_domain(struct device_node *np,
 281                                            struct rmobile_pm_domain *pd)
 282 {
 283         const char *name = pd->genpd.name;
 284
 285         switch (pd_type(np)) {
 286         case PD_CPU:
 287                 /*
 288                  * This domain contains the CPU core and therefore it should
 289                  * only be turned off if the CPU is not in use.
 290                  */
 291                 pr_debug("PM domain %s contains CPU\n", name);
 292                 pd->gov = &pm_domain_always_on_gov;
 293                 pd->suspend = rmobile_pd_suspend_busy;
 294                 break;
 295
 296         case PD_CONSOLE:
 297                 pr_debug("PM domain %s contains serial console\n", name);
 298                 pd->gov = &pm_domain_always_on_gov;
 299                 pd->suspend = rmobile_pd_suspend_console;
 300                 break;
 301
 302         case PD_DEBUG:
 303                 /*
 304                  * This domain contains the Coresight-ETM hardware block and
 305                  * therefore it should only be turned off if the debug module
 306                  * is not in use.
 307                  */
 308                 pr_debug("PM domain %s contains Coresight-ETM\n", name);
 309                 pd->gov = &pm_domain_always_on_gov;
 310                 pd->suspend = rmobile_pd_suspend_busy;
 311                 break;
 312
 313         case PD_MEMCTL:
 314                 /*
 315                  * This domain contains a memory-controller and therefore it
 316                  * should only be turned off if memory is not in use.
 317                  */
 318                 pr_debug("PM domain %s contains MEMCTL\n", name);
 319                 pd->gov = &pm_domain_always_on_gov;
 320                 pd->suspend = rmobile_pd_suspend_busy;
 321                 break;
 322
 323         case PD_NORMAL:
 324                 break;
 325         }
 326
 327         rmobile_init_pm_domain(pd);
 328 }
 329
 330 static int __init rmobile_add_pm_domains(void __iomem *base,
 331                                          struct device_node *parent,
 332                                          struct generic_pm_domain *genpd_parent)
 333 {
 334         struct device_node *np;
 335
 336         for_each_child_of_node(parent, np) {
 337                 struct rmobile_pm_domain *pd;
 338                 u32 idx = ~0;
 339
 340                 if (of_property_read_u32(np, "reg", &idx)) {
 341                         /* always-on domain */
 342                 }
 343
 344                 pd = kzalloc(sizeof(*pd), GFP_KERNEL);
 345                 if (!pd)
 346                         return -ENOMEM;
 347
 348                 pd->genpd.name = np->name;
 349                 pd->base = base;
 350                 pd->bit_shift = idx;
 351
 352                 rmobile_setup_pm_domain(np, pd);
 353                 if (genpd_parent)
 354                         pm_genpd_add_subdomain(genpd_parent, &pd->genpd);
 355                 of_genpd_add_provider_simple(np, &pd->genpd);
 356
 357                 rmobile_add_pm_domains(base, np, &pd->genpd);
 358         }
 359         return 0;
 360 }
 361
 362 static int __init rmobile_init_pm_domains(void)
 363 {
 364         struct device_node *np, *pmd;
 365         bool scanned = false;
 366         void __iomem *base;
 367         int ret = 0;
 368
 369         for_each_compatible_node(np, NULL, "renesas,sysc-rmobile") {
 370                 base = of_iomap(np, 0);
 371                 if (!base) {
 372                         pr_warn("%s cannot map reg 0\n", np->full_name);
 373                         continue;
 374                 }
 375
 376                 pmd = of_get_child_by_name(np, "pm-domains");
 377                 if (!pmd) {
 378                         pr_warn("%s lacks pm-domains node\n", np->full_name);
 379                         continue;
 380                 }
 381
 382                 if (!scanned) {
 383                         /* Find PM domains containing special blocks */
 384                         get_special_pds();
 385                         scanned = true;
 386                 }
 387
 388                 ret = rmobile_add_pm_domains(base, pmd, NULL);
 389                 of_node_put(pmd);
 390                 if (ret) {
 391                         of_node_put(np);
 392                         break;
 393                 }
 394         }
 395
 396         put_special_pds();
 397
 398         return ret;
 399 }
 400
 401 core_initcall(rmobile_init_pm_domains);