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