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