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

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * rmobile power management support
   4  *
   5  * Copyright (C) 2012  Renesas Solutions Corp.
   6  * Copyright (C) 2012  Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
   7  * Copyright (C) 2014  Glider bvba
   8  *
   9  * based on pm-sh7372.c
  10  *  Copyright (C) 2011 Magnus Damm
  11  */
  12 #include <linux/clk/renesas.h>
  13 #include <linux/console.h>
  14 #include <linux/delay.h>
  15 #include <linux/of.h>
  16 #include <linux/of_address.h>
  17 #include <linux/of_platform.h>
  18 #include <linux/platform_device.h>
  19 #include <linux/pm.h>
  20 #include <linux/pm_clock.h>
  21 #include <linux/slab.h>
  22
  23 #include <asm/io.h>
  24
  25 #include "pm-rmobile.h"
  26
  27 /* SYSC */
  28 #define SPDCR           0x08    /* SYS Power Down Control Register */
  29 #define SWUCR           0x14    /* SYS Wakeup Control Register */
  30 #define PSTR            0x80    /* Power Status Register */
  31
  32 #define PSTR_RETRIES    100
  33 #define PSTR_DELAY_US   10
  34
  35 static inline
  36 struct rmobile_pm_domain *to_rmobile_pd(struct generic_pm_domain *d)
  37 {
  38         return container_of(d, struct rmobile_pm_domain, genpd);
  39 }
  40
  41 static int rmobile_pd_power_down(struct generic_pm_domain *genpd)
  42 {
  43         struct rmobile_pm_domain *rmobile_pd = to_rmobile_pd(genpd);
  44         unsigned int mask;
  45
  46         if (rmobile_pd->bit_shift == ~0)
  47                 return -EBUSY;
  48
  49         mask = BIT(rmobile_pd->bit_shift);
  50         if (rmobile_pd->suspend) {
  51                 int ret = rmobile_pd->suspend();
  52
  53                 if (ret)
  54                         return ret;
  55         }
  56
  57         if (__raw_readl(rmobile_pd->base + PSTR) & mask) {
  58                 unsigned int retry_count;
  59                 __raw_writel(mask, rmobile_pd->base + SPDCR);
  60
  61                 for (retry_count = PSTR_RETRIES; retry_count; retry_count--) {
  62                         if (!(__raw_readl(rmobile_pd->base + SPDCR) & mask))
  63                                 break;
  64                         cpu_relax();
  65                 }
  66         }
  67
  68         if (!rmobile_pd->no_debug)
  69                 pr_debug("%s: Power off, 0x%08x -> PSTR = 0x%08x\n",
  70                          genpd->name, mask,
  71                          __raw_readl(rmobile_pd->base + PSTR));
  72
  73         return 0;
  74 }
  75
  76 static int __rmobile_pd_power_up(struct rmobile_pm_domain *rmobile_pd,
  77                                  bool do_resume)
  78 {
  79         unsigned int mask;
  80         unsigned int retry_count;
  81         int ret = 0;
  82
  83         if (rmobile_pd->bit_shift == ~0)
  84                 return 0;
  85
  86         mask = BIT(rmobile_pd->bit_shift);
  87         if (__raw_readl(rmobile_pd->base + PSTR) & mask)
  88                 goto out;
  89
  90         __raw_writel(mask, rmobile_pd->base + SWUCR);
  91
  92         for (retry_count = 2 * PSTR_RETRIES; retry_count; retry_count--) {
  93                 if (!(__raw_readl(rmobile_pd->base + SWUCR) & mask))
  94                         break;
  95                 if (retry_count > PSTR_RETRIES)
  96                         udelay(PSTR_DELAY_US);
  97                 else
  98                         cpu_relax();
  99         }
 100         if (!retry_count)
 101                 ret = -EIO;
 102
 103         if (!rmobile_pd->no_debug)
 104                 pr_debug("%s: Power on, 0x%08x -> PSTR = 0x%08x\n",
 105                          rmobile_pd->genpd.name, mask,
 106                          __raw_readl(rmobile_pd->base + PSTR));
 107
 108 out:
 109         if (ret == 0 && rmobile_pd->resume && do_resume)
 110                 rmobile_pd->resume();
 111
 112         return ret;
 113 }
 114
 115 static int rmobile_pd_power_up(struct generic_pm_domain *genpd)
 116 {
 117         return __rmobile_pd_power_up(to_rmobile_pd(genpd), true);
 118 }
 119
 120 static void rmobile_init_pm_domain(struct rmobile_pm_domain *rmobile_pd)
 121 {
 122         struct generic_pm_domain *genpd = &rmobile_pd->genpd;
 123         struct dev_power_governor *gov = rmobile_pd->gov;
 124
 125         genpd->flags |= GENPD_FLAG_PM_CLK | GENPD_FLAG_ACTIVE_WAKEUP;
 126         genpd->power_off                = rmobile_pd_power_down;
 127         genpd->power_on                 = rmobile_pd_power_up;
 128         genpd->attach_dev               = cpg_mstp_attach_dev;
 129         genpd->detach_dev               = cpg_mstp_detach_dev;
 130         __rmobile_pd_power_up(rmobile_pd, false);
 131         pm_genpd_init(genpd, gov ? : &simple_qos_governor, false);
 132 }
 133
 134 static int rmobile_pd_suspend_console(void)
 135 {
 136         /*
 137          * Serial consoles make use of SCIF hardware located in this domain,
 138          * hence keep the power domain on if "no_console_suspend" is set.
 139          */
 140         return console_suspend_enabled ? 0 : -EBUSY;
 141 }
 142
 143 enum pd_types {
 144         PD_NORMAL,
 145         PD_CPU,
 146         PD_CONSOLE,
 147         PD_DEBUG,
 148         PD_MEMCTL,
 149 };
 150
 151 #define MAX_NUM_SPECIAL_PDS     16
 152
 153 static struct special_pd {
 154         struct device_node *pd;
 155         enum pd_types type;
 156 } special_pds[MAX_NUM_SPECIAL_PDS] __initdata;
 157
 158 static unsigned int num_special_pds __initdata;
 159
 160 static const struct of_device_id special_ids[] __initconst = {
 161         { .compatible = "arm,coresight-etm3x", .data = (void *)PD_DEBUG },
 162         { .compatible = "renesas,dbsc-r8a73a4", .data = (void *)PD_MEMCTL, },
 163         { .compatible = "renesas,dbsc3-r8a7740", .data = (void *)PD_MEMCTL, },
 164         { .compatible = "renesas,sbsc-sh73a0", .data = (void *)PD_MEMCTL, },
 165         { /* sentinel */ },
 166 };
 167
 168 static void __init add_special_pd(struct device_node *np, enum pd_types type)
 169 {
 170         unsigned int i;
 171         struct device_node *pd;
 172
 173         pd = of_parse_phandle(np, "power-domains", 0);
 174         if (!pd)
 175                 return;
 176
 177         for (i = 0; i < num_special_pds; i++)
 178                 if (pd == special_pds[i].pd && type == special_pds[i].type) {
 179                         of_node_put(pd);
 180                         return;
 181                 }
 182
 183         if (num_special_pds == ARRAY_SIZE(special_pds)) {
 184                 pr_warn("Too many special PM domains\n");
 185                 of_node_put(pd);
 186                 return;
 187         }
 188
 189         pr_debug("Special PM domain %pOFn type %d for %pOF\n", pd, type, np);
 190
 191         special_pds[num_special_pds].pd = pd;
 192         special_pds[num_special_pds].type = type;
 193         num_special_pds++;
 194 }
 195
 196 static void __init get_special_pds(void)
 197 {
 198         struct device_node *np;
 199         const struct of_device_id *id;
 200
 201         /* PM domains containing CPUs */
 202         for_each_of_cpu_node(np)
 203                 add_special_pd(np, PD_CPU);
 204
 205         /* PM domain containing console */
 206         if (of_stdout)
 207                 add_special_pd(of_stdout, PD_CONSOLE);
 208
 209         /* PM domains containing other special devices */
 210         for_each_matching_node_and_match(np, special_ids, &id)
 211                 add_special_pd(np, (enum pd_types)id->data);
 212 }
 213
 214 static void __init put_special_pds(void)
 215 {
 216         unsigned int i;
 217
 218         for (i = 0; i < num_special_pds; i++)
 219                 of_node_put(special_pds[i].pd);
 220 }
 221
 222 static enum pd_types __init pd_type(const struct device_node *pd)
 223 {
 224         unsigned int i;
 225
 226         for (i = 0; i < num_special_pds; i++)
 227                 if (pd == special_pds[i].pd)
 228                         return special_pds[i].type;
 229
 230         return PD_NORMAL;
 231 }
 232
 233 static void __init rmobile_setup_pm_domain(struct device_node *np,
 234                                            struct rmobile_pm_domain *pd)
 235 {
 236         const char *name = pd->genpd.name;
 237
 238         switch (pd_type(np)) {
 239         case PD_CPU:
 240                 /*
 241                  * This domain contains the CPU core and therefore it should
 242                  * only be turned off if the CPU is not in use.
 243                  */
 244                 pr_debug("PM domain %s contains CPU\n", name);
 245                 pd->genpd.flags |= GENPD_FLAG_ALWAYS_ON;
 246                 break;
 247
 248         case PD_CONSOLE:
 249                 pr_debug("PM domain %s contains serial console\n", name);
 250                 pd->gov = &pm_domain_always_on_gov;
 251                 pd->suspend = rmobile_pd_suspend_console;
 252                 break;
 253
 254         case PD_DEBUG:
 255                 /*
 256                  * This domain contains the Coresight-ETM hardware block and
 257                  * therefore it should only be turned off if the debug module
 258                  * is not in use.
 259                  */
 260                 pr_debug("PM domain %s contains Coresight-ETM\n", name);
 261                 pd->genpd.flags |= GENPD_FLAG_ALWAYS_ON;
 262                 break;
 263
 264         case PD_MEMCTL:
 265                 /*
 266                  * This domain contains a memory-controller and therefore it
 267                  * should only be turned off if memory is not in use.
 268                  */
 269                 pr_debug("PM domain %s contains MEMCTL\n", name);
 270                 pd->genpd.flags |= GENPD_FLAG_ALWAYS_ON;
 271                 break;
 272
 273         case PD_NORMAL:
 274                 break;
 275         }
 276
 277         rmobile_init_pm_domain(pd);
 278 }
 279
 280 static int __init rmobile_add_pm_domains(void __iomem *base,
 281                                          struct device_node *parent,
 282                                          struct generic_pm_domain *genpd_parent)
 283 {
 284         struct device_node *np;
 285
 286         for_each_child_of_node(parent, np) {
 287                 struct rmobile_pm_domain *pd;
 288                 u32 idx = ~0;
 289
 290                 if (of_property_read_u32(np, "reg", &idx)) {
 291                         /* always-on domain */
 292                 }
 293
 294                 pd = kzalloc(sizeof(*pd), GFP_KERNEL);
 295                 if (!pd) {
 296                         of_node_put(np);
 297                         return -ENOMEM;
 298                 }
 299
 300                 pd->genpd.name = np->name;
 301                 pd->base = base;
 302                 pd->bit_shift = idx;
 303
 304                 rmobile_setup_pm_domain(np, pd);
 305                 if (genpd_parent)
 306                         pm_genpd_add_subdomain(genpd_parent, &pd->genpd);
 307                 of_genpd_add_provider_simple(np, &pd->genpd);
 308
 309                 rmobile_add_pm_domains(base, np, &pd->genpd);
 310         }
 311         return 0;
 312 }
 313
 314 static int __init rmobile_init_pm_domains(void)
 315 {
 316         struct device_node *np, *pmd;
 317         bool scanned = false;
 318         void __iomem *base;
 319         int ret = 0;
 320
 321         for_each_compatible_node(np, NULL, "renesas,sysc-rmobile") {
 322                 base = of_iomap(np, 0);
 323                 if (!base) {
 324                         pr_warn("%pOF cannot map reg 0\n", np);
 325                         continue;
 326                 }
 327
 328                 pmd = of_get_child_by_name(np, "pm-domains");
 329                 if (!pmd) {
 330                         pr_warn("%pOF lacks pm-domains node\n", np);
 331                         continue;
 332                 }
 333
 334                 if (!scanned) {
 335                         /* Find PM domains containing special blocks */
 336                         get_special_pds();
 337                         scanned = true;
 338                 }
 339
 340                 ret = rmobile_add_pm_domains(base, pmd, NULL);
 341                 of_node_put(pmd);
 342                 if (ret) {
 343                         of_node_put(np);
 344                         break;
 345                 }
 346         }
 347
 348         put_special_pds();
 349
 350         return ret;
 351 }
 352
 353 core_initcall(rmobile_init_pm_domains);