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