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