arch/powerpc/platforms/83xx/suspend.c

   1 /*
   2  * MPC83xx suspend support
   3  *
   4  * Author: Scott Wood <scottwood@freescale.com>
   5  *
   6  * Copyright (c) 2006-2007 Freescale Semiconductor, Inc.
   7  *
   8  * This program is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU General Public License version 2 as published
  10  * by the Free Software Foundation.
  11  */
  12
  13 #include <linux/pm.h>
  14 #include <linux/types.h>
  15 #include <linux/ioport.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/wait.h>
  18 #include <linux/kthread.h>
  19 #include <linux/freezer.h>
  20 #include <linux/suspend.h>
  21 #include <linux/fsl_devices.h>
  22 #include <linux/of_address.h>
  23 #include <linux/of_irq.h>
  24 #include <linux/of_platform.h>
  25 #include <linux/export.h>
  26
  27 #include <asm/reg.h>
  28 #include <asm/io.h>
  29 #include <asm/time.h>
  30 #include <asm/mpc6xx.h>
  31 #include <asm/switch_to.h>
  32
  33 #include <sysdev/fsl_soc.h>
  34
  35 #define PMCCR1_NEXT_STATE       0x0C /* Next state for power management */
  36 #define PMCCR1_NEXT_STATE_SHIFT 2
  37 #define PMCCR1_CURR_STATE       0x03 /* Current state for power management*/
  38 #define IMMR_SYSCR_OFFSET       0x100
  39 #define IMMR_RCW_OFFSET         0x900
  40 #define RCW_PCI_HOST            0x80000000
  41
  42 void mpc83xx_enter_deep_sleep(phys_addr_t immrbase);
  43
  44 struct mpc83xx_pmc {
  45         u32 config;
  46 #define PMCCR_DLPEN 2 /* DDR SDRAM low power enable */
  47 #define PMCCR_SLPEN 1 /* System low power enable */
  48
  49         u32 event;
  50         u32 mask;
  51 /* All but PMCI are deep-sleep only */
  52 #define PMCER_GPIO   0x100
  53 #define PMCER_PCI    0x080
  54 #define PMCER_USB    0x040
  55 #define PMCER_ETSEC1 0x020
  56 #define PMCER_ETSEC2 0x010
  57 #define PMCER_TIMER  0x008
  58 #define PMCER_INT1   0x004
  59 #define PMCER_INT2   0x002
  60 #define PMCER_PMCI   0x001
  61 #define PMCER_ALL    0x1FF
  62
  63         /* deep-sleep only */
  64         u32 config1;
  65 #define PMCCR1_USE_STATE  0x80000000
  66 #define PMCCR1_PME_EN     0x00000080
  67 #define PMCCR1_ASSERT_PME 0x00000040
  68 #define PMCCR1_POWER_OFF  0x00000020
  69
  70         /* deep-sleep only */
  71         u32 config2;
  72 };
  73
  74 struct mpc83xx_rcw {
  75         u32 rcwlr;
  76         u32 rcwhr;
  77 };
  78
  79 struct mpc83xx_clock {
  80         u32 spmr;
  81         u32 occr;
  82         u32 sccr;
  83 };
  84
  85 struct mpc83xx_syscr {
  86         __be32 sgprl;
  87         __be32 sgprh;
  88         __be32 spridr;
  89         __be32 :32;
  90         __be32 spcr;
  91         __be32 sicrl;
  92         __be32 sicrh;
  93 };
  94
  95 struct mpc83xx_saved {
  96         u32 sicrl;
  97         u32 sicrh;
  98         u32 sccr;
  99 };
 100
 101 struct pmc_type {
 102         int has_deep_sleep;
 103 };
 104
 105 static struct platform_device *pmc_dev;
 106 static int has_deep_sleep, deep_sleeping;
 107 static int pmc_irq;
 108 static struct mpc83xx_pmc __iomem *pmc_regs;
 109 static struct mpc83xx_clock __iomem *clock_regs;
 110 static struct mpc83xx_syscr __iomem *syscr_regs;
 111 static struct mpc83xx_saved saved_regs;
 112 static int is_pci_agent, wake_from_pci;
 113 static phys_addr_t immrbase;
 114 static int pci_pm_state;
 115 static DECLARE_WAIT_QUEUE_HEAD(agent_wq);
 116
 117 int fsl_deep_sleep(void)
 118 {
 119         return deep_sleeping;
 120 }
 121 EXPORT_SYMBOL(fsl_deep_sleep);
 122
 123 static int mpc83xx_change_state(void)
 124 {
 125         u32 curr_state;
 126         u32 reg_cfg1 = in_be32(&pmc_regs->config1);
 127
 128         if (is_pci_agent) {
 129                 pci_pm_state = (reg_cfg1 & PMCCR1_NEXT_STATE) >>
 130                                PMCCR1_NEXT_STATE_SHIFT;
 131                 curr_state = reg_cfg1 & PMCCR1_CURR_STATE;
 132
 133                 if (curr_state != pci_pm_state) {
 134                         reg_cfg1 &= ~PMCCR1_CURR_STATE;
 135                         reg_cfg1 |= pci_pm_state;
 136                         out_be32(&pmc_regs->config1, reg_cfg1);
 137
 138                         wake_up(&agent_wq);
 139                         return 1;
 140                 }
 141         }
 142
 143         return 0;
 144 }
 145
 146 static irqreturn_t pmc_irq_handler(int irq, void *dev_id)
 147 {
 148         u32 event = in_be32(&pmc_regs->event);
 149         int ret = IRQ_NONE;
 150
 151         if (mpc83xx_change_state())
 152                 ret = IRQ_HANDLED;
 153
 154         if (event) {
 155                 out_be32(&pmc_regs->event, event);
 156                 ret = IRQ_HANDLED;
 157         }
 158
 159         return ret;
 160 }
 161
 162 static void mpc83xx_suspend_restore_regs(void)
 163 {
 164         out_be32(&syscr_regs->sicrl, saved_regs.sicrl);
 165         out_be32(&syscr_regs->sicrh, saved_regs.sicrh);
 166         out_be32(&clock_regs->sccr, saved_regs.sccr);
 167 }
 168
 169 static void mpc83xx_suspend_save_regs(void)
 170 {
 171         saved_regs.sicrl = in_be32(&syscr_regs->sicrl);
 172         saved_regs.sicrh = in_be32(&syscr_regs->sicrh);
 173         saved_regs.sccr = in_be32(&clock_regs->sccr);
 174 }
 175
 176 static int mpc83xx_suspend_enter(suspend_state_t state)
 177 {
 178         int ret = -EAGAIN;
 179
 180         /* Don't go to sleep if there's a race where pci_pm_state changes
 181          * between the agent thread checking it and the PM code disabling
 182          * interrupts.
 183          */
 184         if (wake_from_pci) {
 185                 if (pci_pm_state != (deep_sleeping ? 3 : 2))
 186                         goto out;
 187
 188                 out_be32(&pmc_regs->config1,
 189                          in_be32(&pmc_regs->config1) | PMCCR1_PME_EN);
 190         }
 191
 192         /* Put the system into low-power mode and the RAM
 193          * into self-refresh mode once the core goes to
 194          * sleep.
 195          */
 196
 197         out_be32(&pmc_regs->config, PMCCR_SLPEN | PMCCR_DLPEN);
 198
 199         /* If it has deep sleep (i.e. it's an 831x or compatible),
 200          * disable power to the core upon entering sleep mode.  This will
 201          * require going through the boot firmware upon a wakeup event.
 202          */
 203
 204         if (deep_sleeping) {
 205                 mpc83xx_suspend_save_regs();
 206
 207                 out_be32(&pmc_regs->mask, PMCER_ALL);
 208
 209                 out_be32(&pmc_regs->config1,
 210                          in_be32(&pmc_regs->config1) | PMCCR1_POWER_OFF);
 211
 212                 enable_kernel_fp();
 213
 214                 mpc83xx_enter_deep_sleep(immrbase);
 215
 216                 out_be32(&pmc_regs->config1,
 217                          in_be32(&pmc_regs->config1) & ~PMCCR1_POWER_OFF);
 218
 219                 out_be32(&pmc_regs->mask, PMCER_PMCI);
 220
 221                 mpc83xx_suspend_restore_regs();
 222         } else {
 223                 out_be32(&pmc_regs->mask, PMCER_PMCI);
 224
 225                 mpc6xx_enter_standby();
 226         }
 227
 228         ret = 0;
 229
 230 out:
 231         out_be32(&pmc_regs->config1,
 232                  in_be32(&pmc_regs->config1) & ~PMCCR1_PME_EN);
 233
 234         return ret;
 235 }
 236
 237 static void mpc83xx_suspend_end(void)
 238 {
 239         deep_sleeping = 0;
 240 }
 241
 242 static int mpc83xx_suspend_valid(suspend_state_t state)
 243 {
 244         return state == PM_SUSPEND_STANDBY || state == PM_SUSPEND_MEM;
 245 }
 246
 247 static int mpc83xx_suspend_begin(suspend_state_t state)
 248 {
 249         switch (state) {
 250                 case PM_SUSPEND_STANDBY:
 251                         deep_sleeping = 0;
 252                         return 0;
 253
 254                 case PM_SUSPEND_MEM:
 255                         if (has_deep_sleep)
 256                                 deep_sleeping = 1;
 257
 258                         return 0;
 259
 260                 default:
 261                         return -EINVAL;
 262         }
 263 }
 264
 265 static int agent_thread_fn(void *data)
 266 {
 267         while (1) {
 268                 wait_event_interruptible(agent_wq, pci_pm_state >= 2);
 269                 try_to_freeze();
 270
 271                 if (signal_pending(current) || pci_pm_state < 2)
 272                         continue;
 273
 274                 /* With a preemptible kernel (or SMP), this could race with
 275                  * a userspace-driven suspend request.  It's probably best
 276                  * to avoid mixing the two with such a configuration (or
 277                  * else fix it by adding a mutex to state_store that we can
 278                  * synchronize with).
 279                  */
 280
 281                 wake_from_pci = 1;
 282
 283                 pm_suspend(pci_pm_state == 3 ? PM_SUSPEND_MEM :
 284                                                PM_SUSPEND_STANDBY);
 285
 286                 wake_from_pci = 0;
 287         }
 288
 289         return 0;
 290 }
 291
 292 static void mpc83xx_set_agent(void)
 293 {
 294         out_be32(&pmc_regs->config1, PMCCR1_USE_STATE);
 295         out_be32(&pmc_regs->mask, PMCER_PMCI);
 296
 297         kthread_run(agent_thread_fn, NULL, "PCI power mgt");
 298 }
 299
 300 static int mpc83xx_is_pci_agent(void)
 301 {
 302         struct mpc83xx_rcw __iomem *rcw_regs;
 303         int ret;
 304
 305         rcw_regs = ioremap(get_immrbase() + IMMR_RCW_OFFSET,
 306                            sizeof(struct mpc83xx_rcw));
 307
 308         if (!rcw_regs)
 309                 return -ENOMEM;
 310
 311         ret = !(in_be32(&rcw_regs->rcwhr) & RCW_PCI_HOST);
 312
 313         iounmap(rcw_regs);
 314         return ret;
 315 }
 316
 317 static const struct platform_suspend_ops mpc83xx_suspend_ops = {
 318         .valid = mpc83xx_suspend_valid,
 319         .begin = mpc83xx_suspend_begin,
 320         .enter = mpc83xx_suspend_enter,
 321         .end = mpc83xx_suspend_end,
 322 };
 323
 324 static const struct of_device_id pmc_match[];
 325 static int pmc_probe(struct platform_device *ofdev)
 326 {
 327         const struct of_device_id *match;
 328         struct device_node *np = ofdev->dev.of_node;
 329         struct resource res;
 330         const struct pmc_type *type;
 331         int ret = 0;
 332
 333         match = of_match_device(pmc_match, &ofdev->dev);
 334         if (!match)
 335                 return -EINVAL;
 336
 337         type = match->data;
 338
 339         if (!of_device_is_available(np))
 340                 return -ENODEV;
 341
 342         has_deep_sleep = type->has_deep_sleep;
 343         immrbase = get_immrbase();
 344         pmc_dev = ofdev;
 345
 346         is_pci_agent = mpc83xx_is_pci_agent();
 347         if (is_pci_agent < 0)
 348                 return is_pci_agent;
 349
 350         ret = of_address_to_resource(np, 0, &res);
 351         if (ret)
 352                 return -ENODEV;
 353
 354         pmc_irq = irq_of_parse_and_map(np, 0);
 355         if (pmc_irq) {
 356                 ret = request_irq(pmc_irq, pmc_irq_handler, IRQF_SHARED,
 357                                   "pmc", ofdev);
 358
 359                 if (ret)
 360                         return -EBUSY;
 361         }
 362
 363         pmc_regs = ioremap(res.start, sizeof(struct mpc83xx_pmc));
 364
 365         if (!pmc_regs) {
 366                 ret = -ENOMEM;
 367                 goto out;
 368         }
 369
 370         ret = of_address_to_resource(np, 1, &res);
 371         if (ret) {
 372                 ret = -ENODEV;
 373                 goto out_pmc;
 374         }
 375
 376         clock_regs = ioremap(res.start, sizeof(struct mpc83xx_pmc));
 377
 378         if (!clock_regs) {
 379                 ret = -ENOMEM;
 380                 goto out_pmc;
 381         }
 382
 383         if (has_deep_sleep) {
 384                 syscr_regs = ioremap(immrbase + IMMR_SYSCR_OFFSET,
 385                                      sizeof(*syscr_regs));
 386                 if (!syscr_regs) {
 387                         ret = -ENOMEM;
 388                         goto out_syscr;
 389                 }
 390         }
 391
 392         if (is_pci_agent)
 393                 mpc83xx_set_agent();
 394
 395         suspend_set_ops(&mpc83xx_suspend_ops);
 396         return 0;
 397
 398 out_syscr:
 399         iounmap(clock_regs);
 400 out_pmc:
 401         iounmap(pmc_regs);
 402 out:
 403         if (pmc_irq)
 404                 free_irq(pmc_irq, ofdev);
 405
 406         return ret;
 407 }
 408
 409 static int pmc_remove(struct platform_device *ofdev)
 410 {
 411         return -EPERM;
 412 };
 413
 414 static struct pmc_type pmc_types[] = {
 415         {
 416                 .has_deep_sleep = 1,
 417         },
 418         {
 419                 .has_deep_sleep = 0,
 420         }
 421 };
 422
 423 static const struct of_device_id pmc_match[] = {
 424         {
 425                 .compatible = "fsl,mpc8313-pmc",
 426                 .data = &pmc_types[0],
 427         },
 428         {
 429                 .compatible = "fsl,mpc8349-pmc",
 430                 .data = &pmc_types[1],
 431         },
 432         {}
 433 };
 434
 435 static struct platform_driver pmc_driver = {
 436         .driver = {
 437                 .name = "mpc83xx-pmc",
 438                 .of_match_table = pmc_match,
 439         },
 440         .probe = pmc_probe,
 441         .remove = pmc_remove
 442 };
 443
 444 builtin_platform_driver(pmc_driver);