release/src-rt-6.x.4708/linux/linux-2.6.36/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/init.h>
  14 #include <linux/pm.h>
  15 #include <linux/types.h>
  16 #include <linux/ioport.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/wait.h>
  19 #include <linux/kthread.h>
  20 #include <linux/freezer.h>
  21 #include <linux/suspend.h>
  22 #include <linux/fsl_devices.h>
  23 #include <linux/of_platform.h>
  24
  25 #include <asm/reg.h>
  26 #include <asm/io.h>
  27 #include <asm/time.h>
  28 #include <asm/mpc6xx.h>
  29
  30 #include <sysdev/fsl_soc.h>
  31
  32 #define PMCCR1_NEXT_STATE       0x0C /* Next state for power management */
  33 #define PMCCR1_NEXT_STATE_SHIFT 2
  34 #define PMCCR1_CURR_STATE       0x03 /* Current state for power management*/
  35 #define IMMR_SYSCR_OFFSET       0x100
  36 #define IMMR_RCW_OFFSET         0x900
  37 #define RCW_PCI_HOST            0x80000000
  38
  39 void mpc83xx_enter_deep_sleep(phys_addr_t immrbase);
  40
  41 struct mpc83xx_pmc {
  42         u32 config;
  43 #define PMCCR_DLPEN 2 /* DDR SDRAM low power enable */
  44 #define PMCCR_SLPEN 1 /* System low power enable */
  45
  46         u32 event;
  47         u32 mask;
  48 /* All but PMCI are deep-sleep only */
  49 #define PMCER_GPIO   0x100
  50 #define PMCER_PCI    0x080
  51 #define PMCER_USB    0x040
  52 #define PMCER_ETSEC1 0x020
  53 #define PMCER_ETSEC2 0x010
  54 #define PMCER_TIMER  0x008
  55 #define PMCER_INT1   0x004
  56 #define PMCER_INT2   0x002
  57 #define PMCER_PMCI   0x001
  58 #define PMCER_ALL    0x1FF
  59
  60         /* deep-sleep only */
  61         u32 config1;
  62 #define PMCCR1_USE_STATE  0x80000000
  63 #define PMCCR1_PME_EN     0x00000080
  64 #define PMCCR1_ASSERT_PME 0x00000040
  65 #define PMCCR1_POWER_OFF  0x00000020
  66
  67         /* deep-sleep only */
  68         u32 config2;
  69 };
  70
  71 struct mpc83xx_rcw {
  72         u32 rcwlr;
  73         u32 rcwhr;
  74 };
  75
  76 struct mpc83xx_clock {
  77         u32 spmr;
  78         u32 occr;
  79         u32 sccr;
  80 };
  81
  82 struct mpc83xx_syscr {
  83         __be32 sgprl;
  84         __be32 sgprh;
  85         __be32 spridr;
  86         __be32 :32;
  87         __be32 spcr;
  88         __be32 sicrl;
  89         __be32 sicrh;
  90 };
  91
  92 struct mpc83xx_saved {
  93         u32 sicrl;
  94         u32 sicrh;
  95         u32 sccr;
  96 };
  97
  98 struct pmc_type {
  99         int has_deep_sleep;
 100 };
 101
 102 static struct platform_device *pmc_dev;
 103 static int has_deep_sleep, deep_sleeping;
 104 static int pmc_irq;
 105 static struct mpc83xx_pmc __iomem *pmc_regs;
 106 static struct mpc83xx_clock __iomem *clock_regs;
 107 static struct mpc83xx_syscr __iomem *syscr_regs;
 108 static struct mpc83xx_saved saved_regs;
 109 static int is_pci_agent, wake_from_pci;
 110 static phys_addr_t immrbase;
 111 static int pci_pm_state;
 112 static DECLARE_WAIT_QUEUE_HEAD(agent_wq);
 113
 114 int fsl_deep_sleep(void)
 115 {
 116         return deep_sleeping;
 117 }
 118 EXPORT_SYMBOL(fsl_deep_sleep);
 119
 120 static int mpc83xx_change_state(void)
 121 {
 122         u32 curr_state;
 123         u32 reg_cfg1 = in_be32(&pmc_regs->config1);
 124
 125         if (is_pci_agent) {
 126                 pci_pm_state = (reg_cfg1 & PMCCR1_NEXT_STATE) >>
 127                                PMCCR1_NEXT_STATE_SHIFT;
 128                 curr_state = reg_cfg1 & PMCCR1_CURR_STATE;
 129
 130                 if (curr_state != pci_pm_state) {
 131                         reg_cfg1 &= ~PMCCR1_CURR_STATE;
 132                         reg_cfg1 |= pci_pm_state;
 133                         out_be32(&pmc_regs->config1, reg_cfg1);
 134
 135                         wake_up(&agent_wq);
 136                         return 1;
 137                 }
 138         }
 139
 140         return 0;
 141 }
 142
 143 static irqreturn_t pmc_irq_handler(int irq, void *dev_id)
 144 {
 145         u32 event = in_be32(&pmc_regs->event);
 146         int ret = IRQ_NONE;
 147
 148         if (mpc83xx_change_state())
 149                 ret = IRQ_HANDLED;
 150
 151         if (event) {
 152                 out_be32(&pmc_regs->event, event);
 153                 ret = IRQ_HANDLED;
 154         }
 155
 156         return ret;
 157 }
 158
 159 static void mpc83xx_suspend_restore_regs(void)
 160 {
 161         out_be32(&syscr_regs->sicrl, saved_regs.sicrl);
 162         out_be32(&syscr_regs->sicrh, saved_regs.sicrh);
 163         out_be32(&clock_regs->sccr, saved_regs.sccr);
 164 }
 165
 166 static void mpc83xx_suspend_save_regs(void)
 167 {
 168         saved_regs.sicrl = in_be32(&syscr_regs->sicrl);
 169         saved_regs.sicrh = in_be32(&syscr_regs->sicrh);
 170         saved_regs.sccr = in_be32(&clock_regs->sccr);
 171 }
 172
 173 static int mpc83xx_suspend_enter(suspend_state_t state)
 174 {
 175         int ret = -EAGAIN;
 176
 177         /* Don't go to sleep if there's a race where pci_pm_state changes
 178          * between the agent thread checking it and the PM code disabling
 179          * interrupts.
 180          */
 181         if (wake_from_pci) {
 182                 if (pci_pm_state != (deep_sleeping ? 3 : 2))
 183                         goto out;
 184
 185                 out_be32(&pmc_regs->config1,
 186                          in_be32(&pmc_regs->config1) | PMCCR1_PME_EN);
 187         }
 188
 189         /* Put the system into low-power mode and the RAM
 190          * into self-refresh mode once the core goes to
 191          * sleep.
 192          */
 193
 194         out_be32(&pmc_regs->config, PMCCR_SLPEN | PMCCR_DLPEN);
 195
 196         /* If it has deep sleep (i.e. it's an 831x or compatible),
 197          * disable power to the core upon entering sleep mode.  This will
 198          * require going through the boot firmware upon a wakeup event.
 199          */
 200
 201         if (deep_sleeping) {
 202                 mpc83xx_suspend_save_regs();
 203
 204                 out_be32(&pmc_regs->mask, PMCER_ALL);
 205
 206                 out_be32(&pmc_regs->config1,
 207                          in_be32(&pmc_regs->config1) | PMCCR1_POWER_OFF);
 208
 209                 enable_kernel_fp();
 210
 211                 mpc83xx_enter_deep_sleep(immrbase);
 212
 213                 out_be32(&pmc_regs->config1,
 214                          in_be32(&pmc_regs->config1) & ~PMCCR1_POWER_OFF);
 215
 216                 out_be32(&pmc_regs->mask, PMCER_PMCI);
 217
 218                 mpc83xx_suspend_restore_regs();
 219         } else {
 220                 out_be32(&pmc_regs->mask, PMCER_PMCI);
 221
 222                 mpc6xx_enter_standby();
 223         }
 224
 225         ret = 0;
 226
 227 out:
 228         out_be32(&pmc_regs->config1,
 229                  in_be32(&pmc_regs->config1) & ~PMCCR1_PME_EN);
 230
 231         return ret;
 232 }
 233
 234 static void mpc83xx_suspend_end(void)
 235 {
 236         deep_sleeping = 0;
 237 }
 238
 239 static int mpc83xx_suspend_valid(suspend_state_t state)
 240 {
 241         return state == PM_SUSPEND_STANDBY || state == PM_SUSPEND_MEM;
 242 }
 243
 244 static int mpc83xx_suspend_begin(suspend_state_t state)
 245 {
 246         switch (state) {
 247                 case PM_SUSPEND_STANDBY:
 248                         deep_sleeping = 0;
 249                         return 0;
 250
 251                 case PM_SUSPEND_MEM:
 252                         if (has_deep_sleep)
 253                                 deep_sleeping = 1;
 254
 255                         return 0;
 256
 257                 default:
 258                         return -EINVAL;
 259         }
 260 }
 261
 262 static int agent_thread_fn(void *data)
 263 {
 264         while (1) {
 265                 wait_event_interruptible(agent_wq, pci_pm_state >= 2);
 266                 try_to_freeze();
 267
 268                 if (signal_pending(current) || pci_pm_state < 2)
 269                         continue;
 270
 271                 /* With a preemptible kernel (or SMP), this could race with
 272                  * a userspace-driven suspend request.  It's probably best
 273                  * to avoid mixing the two with such a configuration (or
 274                  * else fix it by adding a mutex to state_store that we can
 275                  * synchronize with).
 276                  */
 277
 278                 wake_from_pci = 1;
 279
 280                 pm_suspend(pci_pm_state == 3 ? PM_SUSPEND_MEM :
 281                                                PM_SUSPEND_STANDBY);
 282
 283                 wake_from_pci = 0;
 284         }
 285
 286         return 0;
 287 }
 288
 289 static void mpc83xx_set_agent(void)
 290 {
 291         out_be32(&pmc_regs->config1, PMCCR1_USE_STATE);
 292         out_be32(&pmc_regs->mask, PMCER_PMCI);
 293
 294         kthread_run(agent_thread_fn, NULL, "PCI power mgt");
 295 }
 296
 297 static int mpc83xx_is_pci_agent(void)
 298 {
 299         struct mpc83xx_rcw __iomem *rcw_regs;
 300         int ret;
 301
 302         rcw_regs = ioremap(get_immrbase() + IMMR_RCW_OFFSET,
 303                            sizeof(struct mpc83xx_rcw));
 304
 305         if (!rcw_regs)
 306                 return -ENOMEM;
 307
 308         ret = !(in_be32(&rcw_regs->rcwhr) & RCW_PCI_HOST);
 309
 310         iounmap(rcw_regs);
 311         return ret;
 312 }
 313
 314 static struct platform_suspend_ops mpc83xx_suspend_ops = {
 315         .valid = mpc83xx_suspend_valid,
 316         .begin = mpc83xx_suspend_begin,
 317         .enter = mpc83xx_suspend_enter,
 318         .end = mpc83xx_suspend_end,
 319 };
 320
 321 static int pmc_probe(struct platform_device *ofdev,
 322                      const struct of_device_id *match)
 323 {
 324         struct device_node *np = ofdev->dev.of_node;
 325         struct resource res;
 326         struct pmc_type *type = match->data;
 327         int ret = 0;
 328
 329         if (!of_device_is_available(np))
 330                 return -ENODEV;
 331
 332         has_deep_sleep = type->has_deep_sleep;
 333         immrbase = get_immrbase();
 334         pmc_dev = ofdev;
 335
 336         is_pci_agent = mpc83xx_is_pci_agent();
 337         if (is_pci_agent < 0)
 338                 return is_pci_agent;
 339
 340         ret = of_address_to_resource(np, 0, &res);
 341         if (ret)
 342                 return -ENODEV;
 343
 344         pmc_irq = irq_of_parse_and_map(np, 0);
 345         if (pmc_irq != NO_IRQ) {
 346                 ret = request_irq(pmc_irq, pmc_irq_handler, IRQF_SHARED,
 347                                   "pmc", ofdev);
 348
 349                 if (ret)
 350                         return -EBUSY;
 351         }
 352
 353         pmc_regs = ioremap(res.start, sizeof(struct mpc83xx_pmc));
 354
 355         if (!pmc_regs) {
 356                 ret = -ENOMEM;
 357                 goto out;
 358         }
 359
 360         ret = of_address_to_resource(np, 1, &res);
 361         if (ret) {
 362                 ret = -ENODEV;
 363                 goto out_pmc;
 364         }
 365
 366         clock_regs = ioremap(res.start, sizeof(struct mpc83xx_pmc));
 367
 368         if (!clock_regs) {
 369                 ret = -ENOMEM;
 370                 goto out_pmc;
 371         }
 372
 373         if (has_deep_sleep) {
 374                 syscr_regs = ioremap(immrbase + IMMR_SYSCR_OFFSET,
 375                                      sizeof(*syscr_regs));
 376                 if (!syscr_regs) {
 377                         ret = -ENOMEM;
 378                         goto out_syscr;
 379                 }
 380         }
 381
 382         if (is_pci_agent)
 383                 mpc83xx_set_agent();
 384
 385         suspend_set_ops(&mpc83xx_suspend_ops);
 386         return 0;
 387
 388 out_syscr:
 389         iounmap(clock_regs);
 390 out_pmc:
 391         iounmap(pmc_regs);
 392 out:
 393         if (pmc_irq != NO_IRQ)
 394                 free_irq(pmc_irq, ofdev);
 395
 396         return ret;
 397 }
 398
 399 static int pmc_remove(struct platform_device *ofdev)
 400 {
 401         return -EPERM;
 402 };
 403
 404 static struct pmc_type pmc_types[] = {
 405         {
 406                 .has_deep_sleep = 1,
 407         },
 408         {
 409                 .has_deep_sleep = 0,
 410         }
 411 };
 412
 413 static struct of_device_id pmc_match[] = {
 414         {
 415                 .compatible = "fsl,mpc8313-pmc",
 416                 .data = &pmc_types[0],
 417         },
 418         {
 419                 .compatible = "fsl,mpc8349-pmc",
 420                 .data = &pmc_types[1],
 421         },
 422         {}
 423 };
 424
 425 static struct of_platform_driver pmc_driver = {
 426         .driver = {
 427                 .name = "mpc83xx-pmc",
 428                 .owner = THIS_MODULE,
 429                 .of_match_table = pmc_match,
 430         },
 431         .probe = pmc_probe,
 432         .remove = pmc_remove
 433 };
 434
 435 static int pmc_init(void)
 436 {
 437         return of_register_platform_driver(&pmc_driver);
 438 }
 439
 440 module_init(pmc_init);