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