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/console.h>
  16 #include <linux/delay.h>
  17 #include <linux/of.h>
  18 #include <linux/of_address.h>
  19 #include <linux/of_platform.h>
  20 #include <linux/platform_device.h>
  21 #include <linux/pm.h>
  22 #include <linux/pm_clock.h>
  23 #include <linux/slab.h>
  24
  25 #include <asm/io.h>
  26
  27 #include "pm-rmobile.h"
  28
  29 /* SYSC */
  30 #define SPDCR           0x08    /* SYS Power Down Control Register */
  31 #define SWUCR           0x14    /* SYS Wakeup Control Register */
  32 #define PSTR            0x80    /* Power Status Register */
  33
  34 #define PSTR_RETRIES    100
  35 #define PSTR_DELAY_US   10
  36
  37 static int rmobile_pd_power_down(struct generic_pm_domain *genpd)
  38 {
  39         struct rmobile_pm_domain *rmobile_pd = to_rmobile_pd(genpd);
  40         unsigned int mask;
  41
  42         if (rmobile_pd->bit_shift == ~0)
  43                 return -EBUSY;
  44
  45         mask = 1 << rmobile_pd->bit_shift;
  46         if (rmobile_pd->suspend) {
  47                 int ret = rmobile_pd->suspend();
  48
  49                 if (ret)
  50                         return ret;
  51         }
  52
  53         if (__raw_readl(rmobile_pd->base + PSTR) & mask) {
  54                 unsigned int retry_count;
  55                 __raw_writel(mask, rmobile_pd->base + SPDCR);
  56
  57                 for (retry_count = PSTR_RETRIES; retry_count; retry_count--) {
  58                         if (!(__raw_readl(rmobile_pd->base + SPDCR) & mask))
  59                                 break;
  60                         cpu_relax();
  61                 }
  62         }
  63
  64         if (!rmobile_pd->no_debug)
  65                 pr_debug("%s: Power off, 0x%08x -> PSTR = 0x%08x\n",
  66                          genpd->name, mask,
  67                          __raw_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                                  bool do_resume)
  74 {
  75         unsigned int mask;
  76         unsigned int retry_count;
  77         int ret = 0;
  78
  79         if (rmobile_pd->bit_shift == ~0)
  80                 return 0;
  81
  82         mask = 1 << rmobile_pd->bit_shift;
  83         if (__raw_readl(rmobile_pd->base + PSTR) & mask)
  84                 goto out;
  85
  86         __raw_writel(mask, rmobile_pd->base + SWUCR);
  87
  88         for (retry_count = 2 * PSTR_RETRIES; retry_count; retry_count--) {
  89                 if (!(__raw_readl(rmobile_pd->base + SWUCR) & mask))
  90                         break;
  91                 if (retry_count > PSTR_RETRIES)
  92                         udelay(PSTR_DELAY_US);
  93                 else
  94                         cpu_relax();
  95         }
  96         if (!retry_count)
  97                 ret = -EIO;
  98
  99         if (!rmobile_pd->no_debug)
 100                 pr_debug("%s: Power on, 0x%08x -> PSTR = 0x%08x\n",
 101                          rmobile_pd->genpd.name, mask,
 102                          __raw_readl(rmobile_pd->base + PSTR));
 103
 104 out:
 105         if (ret == 0 && rmobile_pd->resume && do_resume)
 106                 rmobile_pd->resume();
 107
 108         return ret;
 109 }
 110
 111 static int rmobile_pd_power_up(struct generic_pm_domain *genpd)
 112 {
 113         return __rmobile_pd_power_up(to_rmobile_pd(genpd), true);
 114 }
 115
 116 static bool rmobile_pd_active_wakeup(struct device *dev)
 117 {
 118         return true;
 119 }
 120
 121 static int rmobile_pd_attach_dev(struct generic_pm_domain *domain,
 122                                  struct device *dev)
 123 {
 124         int error;
 125
 126         error = pm_clk_create(dev);
 127         if (error) {
 128                 dev_err(dev, "pm_clk_create failed %d\n", error);
 129                 return error;
 130         }
 131
 132         error = pm_clk_add(dev, NULL);
 133         if (error) {
 134                 dev_err(dev, "pm_clk_add failed %d\n", error);
 135                 goto fail;
 136         }
 137
 138         return 0;
 139
 140 fail:
 141         pm_clk_destroy(dev);
 142         return error;
 143 }
 144
 145 static void rmobile_pd_detach_dev(struct generic_pm_domain *domain,
 146                                   struct device *dev)
 147 {
 148         pm_clk_destroy(dev);
 149 }
 150
 151 static void rmobile_init_pm_domain(struct rmobile_pm_domain *rmobile_pd)
 152 {
 153         struct generic_pm_domain *genpd = &rmobile_pd->genpd;
 154         struct dev_power_governor *gov = rmobile_pd->gov;
 155
 156         genpd->flags = GENPD_FLAG_PM_CLK;
 157         pm_genpd_init(genpd, gov ? : &simple_qos_governor, false);
 158         genpd->dev_ops.active_wakeup    = rmobile_pd_active_wakeup;
 159         genpd->power_off                = rmobile_pd_power_down;
 160         genpd->power_on                 = rmobile_pd_power_up;
 161         genpd->attach_dev               = rmobile_pd_attach_dev;
 162         genpd->detach_dev               = rmobile_pd_detach_dev;
 163         __rmobile_pd_power_up(rmobile_pd, false);
 164 }
 165
 166 #ifdef CONFIG_ARCH_SHMOBILE_LEGACY
 167
 168 void rmobile_init_domains(struct rmobile_pm_domain domains[], int num)
 169 {
 170         int j;
 171
 172         for (j = 0; j < num; j++)
 173                 rmobile_init_pm_domain(&domains[j]);
 174 }
 175
 176 void rmobile_add_device_to_domain_td(const char *domain_name,
 177                                      struct platform_device *pdev,
 178                                      struct gpd_timing_data *td)
 179 {
 180         struct device *dev = &pdev->dev;
 181
 182         __pm_genpd_name_add_device(domain_name, dev, td);
 183 }
 184
 185 void rmobile_add_devices_to_domains(struct pm_domain_device data[],
 186                                     int size)
 187 {
 188         struct gpd_timing_data latencies = {
 189                 .stop_latency_ns = DEFAULT_DEV_LATENCY_NS,
 190                 .start_latency_ns = DEFAULT_DEV_LATENCY_NS,
 191                 .save_state_latency_ns = DEFAULT_DEV_LATENCY_NS,
 192                 .restore_state_latency_ns = DEFAULT_DEV_LATENCY_NS,
 193         };
 194         int j;
 195
 196         for (j = 0; j < size; j++)
 197                 rmobile_add_device_to_domain_td(data[j].domain_name,
 198                                                 data[j].pdev, &latencies);
 199 }
 200
 201 #else /* !CONFIG_ARCH_SHMOBILE_LEGACY */
 202
 203 static int rmobile_pd_suspend_cpu(void)
 204 {
 205         /*
 206          * This domain contains the CPU core and therefore it should
 207          * only be turned off if the CPU is not in use.
 208          */
 209         return -EBUSY;
 210 }
 211
 212 static int rmobile_pd_suspend_console(void)
 213 {
 214         /*
 215          * Serial consoles make use of SCIF hardware located in this domain,
 216          * hence keep the power domain on if "no_console_suspend" is set.
 217          */
 218         return console_suspend_enabled ? 0 : -EBUSY;
 219 }
 220
 221 static int rmobile_pd_suspend_debug(void)
 222 {
 223         /*
 224          * This domain contains the Coresight-ETM hardware block and
 225          * therefore it should only be turned off if the debug module is
 226          * not in use.
 227          */
 228         return -EBUSY;
 229 }
 230
 231 #define MAX_NUM_CPU_PDS         8
 232
 233 static unsigned int num_cpu_pds __initdata;
 234 static struct device_node *cpu_pds[MAX_NUM_CPU_PDS] __initdata;
 235 static struct device_node *console_pd __initdata;
 236 static struct device_node *debug_pd __initdata;
 237
 238 static void __init get_special_pds(void)
 239 {
 240         struct device_node *np, *pd;
 241         unsigned int i;
 242
 243         /* PM domains containing CPUs */
 244         for_each_node_by_type(np, "cpu") {
 245                 pd = of_parse_phandle(np, "power-domains", 0);
 246                 if (!pd)
 247                         continue;
 248
 249                 for (i = 0; i < num_cpu_pds; i++)
 250                         if (pd == cpu_pds[i])
 251                                 break;
 252
 253                 if (i < num_cpu_pds) {
 254                         of_node_put(pd);
 255                         continue;
 256                 }
 257
 258                 if (num_cpu_pds == MAX_NUM_CPU_PDS) {
 259                         pr_warn("Too many CPU PM domains\n");
 260                         of_node_put(pd);
 261                         continue;
 262                 }
 263
 264                 cpu_pds[num_cpu_pds++] = pd;
 265         }
 266
 267         /* PM domain containing console */
 268         if (of_stdout)
 269                 console_pd = of_parse_phandle(of_stdout, "power-domains", 0);
 270
 271         /* PM domain containing Coresight-ETM */
 272         np = of_find_compatible_node(NULL, NULL, "arm,coresight-etm3x");
 273         if (np) {
 274                 debug_pd = of_parse_phandle(np, "power-domains", 0);
 275                 of_node_put(np);
 276         }
 277 }
 278
 279 static void __init put_special_pds(void)
 280 {
 281         unsigned int i;
 282
 283         for (i = 0; i < num_cpu_pds; i++)
 284                 of_node_put(cpu_pds[i]);
 285         of_node_put(console_pd);
 286         of_node_put(debug_pd);
 287 }
 288
 289 static bool __init pd_contains_cpu(const struct device_node *pd)
 290 {
 291         unsigned int i;
 292
 293         for (i = 0; i < num_cpu_pds; i++)
 294                 if (pd == cpu_pds[i])
 295                         return true;
 296
 297         return false;
 298 }
 299
 300 static void __init rmobile_setup_pm_domain(struct device_node *np,
 301                                            struct rmobile_pm_domain *pd)
 302 {
 303         const char *name = pd->genpd.name;
 304
 305         if (pd_contains_cpu(np)) {
 306                 pr_debug("PM domain %s contains CPU\n", name);
 307                 pd->gov = &pm_domain_always_on_gov;
 308                 pd->suspend = rmobile_pd_suspend_cpu;
 309         } else if (np == console_pd) {
 310                 pr_debug("PM domain %s contains serial console\n", name);
 311                 pd->gov = &pm_domain_always_on_gov;
 312                 pd->suspend = rmobile_pd_suspend_console;
 313         } else if (np == debug_pd) {
 314                 pr_debug("PM domain %s contains Coresight-ETM\n", name);
 315                 pd->gov = &pm_domain_always_on_gov;
 316                 pd->suspend = rmobile_pd_suspend_debug;
 317         }
 318
 319         rmobile_init_pm_domain(pd);
 320 }
 321
 322 static int __init rmobile_add_pm_domains(void __iomem *base,
 323                                          struct device_node *parent,
 324                                          struct generic_pm_domain *genpd_parent)
 325 {
 326         struct device_node *np;
 327
 328         for_each_child_of_node(parent, np) {
 329                 struct rmobile_pm_domain *pd;
 330                 u32 idx = ~0;
 331
 332                 if (of_property_read_u32(np, "reg", &idx)) {
 333                         /* always-on domain */
 334                 }
 335
 336                 pd = kzalloc(sizeof(*pd), GFP_KERNEL);
 337                 if (!pd)
 338                         return -ENOMEM;
 339
 340                 pd->genpd.name = np->name;
 341                 pd->base = base;
 342                 pd->bit_shift = idx;
 343
 344                 rmobile_setup_pm_domain(np, pd);
 345                 if (genpd_parent)
 346                         pm_genpd_add_subdomain(genpd_parent, &pd->genpd);
 347                 of_genpd_add_provider_simple(np, &pd->genpd);
 348
 349                 rmobile_add_pm_domains(base, np, &pd->genpd);
 350         }
 351         return 0;
 352 }
 353
 354 static int __init rmobile_init_pm_domains(void)
 355 {
 356         struct device_node *np, *pmd;
 357         bool scanned = false;
 358         void __iomem *base;
 359         int ret = 0;
 360
 361         for_each_compatible_node(np, NULL, "renesas,sysc-rmobile") {
 362                 base = of_iomap(np, 0);
 363                 if (!base) {
 364                         pr_warn("%s cannot map reg 0\n", np->full_name);
 365                         continue;
 366                 }
 367
 368                 pmd = of_get_child_by_name(np, "pm-domains");
 369                 if (!pmd) {
 370                         pr_warn("%s lacks pm-domains node\n", np->full_name);
 371                         continue;
 372                 }
 373
 374                 if (!scanned) {
 375                         /* Find PM domains containing special blocks */
 376                         get_special_pds();
 377                         scanned = true;
 378                 }
 379
 380                 ret = rmobile_add_pm_domains(base, pmd, NULL);
 381                 of_node_put(pmd);
 382                 if (ret) {
 383                         of_node_put(np);
 384                         break;
 385                 }
 386         }
 387
 388         put_special_pds();
 389
 390         return ret;
 391 }
 392
 393 core_initcall(rmobile_init_pm_domains);
 394
 395 #endif /* !CONFIG_ARCH_SHMOBILE_LEGACY */