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/renesas.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 void rmobile_init_pm_domain(struct rmobile_pm_domain *rmobile_pd)
 124 {
 125         struct generic_pm_domain *genpd = &rmobile_pd->genpd;
 126         struct dev_power_governor *gov = rmobile_pd->gov;
 127
 128         genpd->flags |= GENPD_FLAG_PM_CLK | GENPD_FLAG_ACTIVE_WAKEUP;
 129         genpd->power_off                = rmobile_pd_power_down;
 130         genpd->power_on                 = rmobile_pd_power_up;
 131         genpd->attach_dev               = cpg_mstp_attach_dev;
 132         genpd->detach_dev               = cpg_mstp_detach_dev;
 133         __rmobile_pd_power_up(rmobile_pd, false);
 134         pm_genpd_init(genpd, gov ? : &simple_qos_governor, false);
 135 }
 136
 137 static int rmobile_pd_suspend_console(void)
 138 {
 139         /*
 140          * Serial consoles make use of SCIF hardware located in this domain,
 141          * hence keep the power domain on if "no_console_suspend" is set.
 142          */
 143         return console_suspend_enabled ? 0 : -EBUSY;
 144 }
 145
 146 enum pd_types {
 147         PD_NORMAL,
 148         PD_CPU,
 149         PD_CONSOLE,
 150         PD_DEBUG,
 151         PD_MEMCTL,
 152 };
 153
 154 #define MAX_NUM_SPECIAL_PDS     16
 155
 156 static struct special_pd {
 157         struct device_node *pd;
 158         enum pd_types type;
 159 } special_pds[MAX_NUM_SPECIAL_PDS] __initdata;
 160
 161 static unsigned int num_special_pds __initdata;
 162
 163 static const struct of_device_id special_ids[] __initconst = {
 164         { .compatible = "arm,coresight-etm3x", .data = (void *)PD_DEBUG },
 165         { .compatible = "renesas,dbsc-r8a73a4", .data = (void *)PD_MEMCTL, },
 166         { .compatible = "renesas,dbsc3-r8a7740", .data = (void *)PD_MEMCTL, },
 167         { .compatible = "renesas,sbsc-sh73a0", .data = (void *)PD_MEMCTL, },
 168         { /* sentinel */ },
 169 };
 170
 171 static void __init add_special_pd(struct device_node *np, enum pd_types type)
 172 {
 173         unsigned int i;
 174         struct device_node *pd;
 175
 176         pd = of_parse_phandle(np, "power-domains", 0);
 177         if (!pd)
 178                 return;
 179
 180         for (i = 0; i < num_special_pds; i++)
 181                 if (pd == special_pds[i].pd && type == special_pds[i].type) {
 182                         of_node_put(pd);
 183                         return;
 184                 }
 185
 186         if (num_special_pds == ARRAY_SIZE(special_pds)) {
 187                 pr_warn("Too many special PM domains\n");
 188                 of_node_put(pd);
 189                 return;
 190         }
 191
 192         pr_debug("Special PM domain %s type %d for %pOF\n", pd->name, type, np);
 193
 194         special_pds[num_special_pds].pd = pd;
 195         special_pds[num_special_pds].type = type;
 196         num_special_pds++;
 197 }
 198
 199 static void __init get_special_pds(void)
 200 {
 201         struct device_node *np;
 202         const struct of_device_id *id;
 203
 204         /* PM domains containing CPUs */
 205         for_each_node_by_type(np, "cpu")
 206                 add_special_pd(np, PD_CPU);
 207
 208         /* PM domain containing console */
 209         if (of_stdout)
 210                 add_special_pd(of_stdout, PD_CONSOLE);
 211
 212         /* PM domains containing other special devices */
 213         for_each_matching_node_and_match(np, special_ids, &id)
 214                 add_special_pd(np, (enum pd_types)id->data);
 215 }
 216
 217 static void __init put_special_pds(void)
 218 {
 219         unsigned int i;
 220
 221         for (i = 0; i < num_special_pds; i++)
 222                 of_node_put(special_pds[i].pd);
 223 }
 224
 225 static enum pd_types __init pd_type(const struct device_node *pd)
 226 {
 227         unsigned int i;
 228
 229         for (i = 0; i < num_special_pds; i++)
 230                 if (pd == special_pds[i].pd)
 231                         return special_pds[i].type;
 232
 233         return PD_NORMAL;
 234 }
 235
 236 static void __init rmobile_setup_pm_domain(struct device_node *np,
 237                                            struct rmobile_pm_domain *pd)
 238 {
 239         const char *name = pd->genpd.name;
 240
 241         switch (pd_type(np)) {
 242         case PD_CPU:
 243                 /*
 244                  * This domain contains the CPU core and therefore it should
 245                  * only be turned off if the CPU is not in use.
 246                  */
 247                 pr_debug("PM domain %s contains CPU\n", name);
 248                 pd->genpd.flags |= GENPD_FLAG_ALWAYS_ON;
 249                 break;
 250
 251         case PD_CONSOLE:
 252                 pr_debug("PM domain %s contains serial console\n", name);
 253                 pd->gov = &pm_domain_always_on_gov;
 254                 pd->suspend = rmobile_pd_suspend_console;
 255                 break;
 256
 257         case PD_DEBUG:
 258                 /*
 259                  * This domain contains the Coresight-ETM hardware block and
 260                  * therefore it should only be turned off if the debug module
 261                  * is not in use.
 262                  */
 263                 pr_debug("PM domain %s contains Coresight-ETM\n", name);
 264                 pd->genpd.flags |= GENPD_FLAG_ALWAYS_ON;
 265                 break;
 266
 267         case PD_MEMCTL:
 268                 /*
 269                  * This domain contains a memory-controller and therefore it
 270                  * should only be turned off if memory is not in use.
 271                  */
 272                 pr_debug("PM domain %s contains MEMCTL\n", name);
 273                 pd->genpd.flags |= GENPD_FLAG_ALWAYS_ON;
 274                 break;
 275
 276         case PD_NORMAL:
 277                 break;
 278         }
 279
 280         rmobile_init_pm_domain(pd);
 281 }
 282
 283 static int __init rmobile_add_pm_domains(void __iomem *base,
 284                                          struct device_node *parent,
 285                                          struct generic_pm_domain *genpd_parent)
 286 {
 287         struct device_node *np;
 288
 289         for_each_child_of_node(parent, np) {
 290                 struct rmobile_pm_domain *pd;
 291                 u32 idx = ~0;
 292
 293                 if (of_property_read_u32(np, "reg", &idx)) {
 294                         /* always-on domain */
 295                 }
 296
 297                 pd = kzalloc(sizeof(*pd), GFP_KERNEL);
 298                 if (!pd) {
 299                         of_node_put(np);
 300                         return -ENOMEM;
 301                 }
 302
 303                 pd->genpd.name = np->name;
 304                 pd->base = base;
 305                 pd->bit_shift = idx;
 306
 307                 rmobile_setup_pm_domain(np, pd);
 308                 if (genpd_parent)
 309                         pm_genpd_add_subdomain(genpd_parent, &pd->genpd);
 310                 of_genpd_add_provider_simple(np, &pd->genpd);
 311
 312                 rmobile_add_pm_domains(base, np, &pd->genpd);
 313         }
 314         return 0;
 315 }
 316
 317 static int __init rmobile_init_pm_domains(void)
 318 {
 319         struct device_node *np, *pmd;
 320         bool scanned = false;
 321         void __iomem *base;
 322         int ret = 0;
 323
 324         for_each_compatible_node(np, NULL, "renesas,sysc-rmobile") {
 325                 base = of_iomap(np, 0);
 326                 if (!base) {
 327                         pr_warn("%pOF cannot map reg 0\n", np);
 328                         continue;
 329                 }
 330
 331                 pmd = of_get_child_by_name(np, "pm-domains");
 332                 if (!pmd) {
 333                         pr_warn("%pOF lacks pm-domains node\n", np);
 334                         continue;
 335                 }
 336
 337                 if (!scanned) {
 338                         /* Find PM domains containing special blocks */
 339                         get_special_pds();
 340                         scanned = true;
 341                 }
 342
 343                 ret = rmobile_add_pm_domains(base, pmd, NULL);
 344                 of_node_put(pmd);
 345                 if (ret) {
 346                         of_node_put(np);
 347                         break;
 348                 }
 349         }
 350
 351         put_special_pds();
 352
 353         return ret;
 354 }
 355
 356 core_initcall(rmobile_init_pm_domains);