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