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_RCW_OFFSET         0x900
  36 #define RCW_PCI_HOST            0x80000000
  37
  38 void mpc83xx_enter_deep_sleep(phys_addr_t immrbase);
  39
  40 struct mpc83xx_pmc {
  41         u32 config;
  42 #define PMCCR_DLPEN 2 /* DDR SDRAM low power enable */
  43 #define PMCCR_SLPEN 1 /* System low power enable */
  44
  45         u32 event;
  46         u32 mask;
  47 /* All but PMCI are deep-sleep only */
  48 #define PMCER_GPIO   0x100
  49 #define PMCER_PCI    0x080
  50 #define PMCER_USB    0x040
  51 #define PMCER_ETSEC1 0x020
  52 #define PMCER_ETSEC2 0x010
  53 #define PMCER_TIMER  0x008
  54 #define PMCER_INT1   0x004
  55 #define PMCER_INT2   0x002
  56 #define PMCER_PMCI   0x001
  57 #define PMCER_ALL    0x1FF
  58
  59         /* deep-sleep only */
  60         u32 config1;
  61 #define PMCCR1_USE_STATE  0x80000000
  62 #define PMCCR1_PME_EN     0x00000080
  63 #define PMCCR1_ASSERT_PME 0x00000040
  64 #define PMCCR1_POWER_OFF  0x00000020
  65
  66         /* deep-sleep only */
  67         u32 config2;
  68 };
  69
  70 struct mpc83xx_rcw {
  71         u32 rcwlr;
  72         u32 rcwhr;
  73 };
  74
  75 struct mpc83xx_clock {
  76         u32 spmr;
  77         u32 occr;
  78         u32 sccr;
  79 };
  80
  81 struct pmc_type {
  82         int has_deep_sleep;
  83 };
  84
  85 static struct of_device *pmc_dev;
  86 static int has_deep_sleep, deep_sleeping;
  87 static int pmc_irq;
  88 static struct mpc83xx_pmc __iomem *pmc_regs;
  89 static struct mpc83xx_clock __iomem *clock_regs;
  90 static int is_pci_agent, wake_from_pci;
  91 static phys_addr_t immrbase;
  92 static int pci_pm_state;
  93 static DECLARE_WAIT_QUEUE_HEAD(agent_wq);
  94
  95 int fsl_deep_sleep(void)
  96 {
  97         return deep_sleeping;
  98 }
  99
 100 static int mpc83xx_change_state(void)
 101 {
 102         u32 curr_state;
 103         u32 reg_cfg1 = in_be32(&pmc_regs->config1);
 104
 105         if (is_pci_agent) {
 106                 pci_pm_state = (reg_cfg1 & PMCCR1_NEXT_STATE) >>
 107                                PMCCR1_NEXT_STATE_SHIFT;
 108                 curr_state = reg_cfg1 & PMCCR1_CURR_STATE;
 109
 110                 if (curr_state != pci_pm_state) {
 111                         reg_cfg1 &= ~PMCCR1_CURR_STATE;
 112                         reg_cfg1 |= pci_pm_state;
 113                         out_be32(&pmc_regs->config1, reg_cfg1);
 114
 115                         wake_up(&agent_wq);
 116                         return 1;
 117                 }
 118         }
 119
 120         return 0;
 121 }
 122
 123 static irqreturn_t pmc_irq_handler(int irq, void *dev_id)
 124 {
 125         u32 event = in_be32(&pmc_regs->event);
 126         int ret = IRQ_NONE;
 127
 128         if (mpc83xx_change_state())
 129                 ret = IRQ_HANDLED;
 130
 131         if (event) {
 132                 out_be32(&pmc_regs->event, event);
 133                 ret = IRQ_HANDLED;
 134         }
 135
 136         return ret;
 137 }
 138
 139 static int mpc83xx_suspend_enter(suspend_state_t state)
 140 {
 141         int ret = -EAGAIN;
 142
 143         /* Don't go to sleep if there's a race where pci_pm_state changes
 144          * between the agent thread checking it and the PM code disabling
 145          * interrupts.
 146          */
 147         if (wake_from_pci) {
 148                 if (pci_pm_state != (deep_sleeping ? 3 : 2))
 149                         goto out;
 150
 151                 out_be32(&pmc_regs->config1,
 152                          in_be32(&pmc_regs->config1) | PMCCR1_PME_EN);
 153         }
 154
 155         /* Put the system into low-power mode and the RAM
 156          * into self-refresh mode once the core goes to
 157          * sleep.
 158          */
 159
 160         out_be32(&pmc_regs->config, PMCCR_SLPEN | PMCCR_DLPEN);
 161
 162         /* If it has deep sleep (i.e. it's an 831x or compatible),
 163          * disable power to the core upon entering sleep mode.  This will
 164          * require going through the boot firmware upon a wakeup event.
 165          */
 166
 167         if (deep_sleeping) {
 168                 out_be32(&pmc_regs->mask, PMCER_ALL);
 169
 170                 out_be32(&pmc_regs->config1,
 171                          in_be32(&pmc_regs->config1) | PMCCR1_POWER_OFF);
 172
 173                 enable_kernel_fp();
 174
 175                 mpc83xx_enter_deep_sleep(immrbase);
 176
 177                 out_be32(&pmc_regs->config1,
 178                          in_be32(&pmc_regs->config1) & ~PMCCR1_POWER_OFF);
 179
 180                 out_be32(&pmc_regs->mask, PMCER_PMCI);
 181         } else {
 182                 out_be32(&pmc_regs->mask, PMCER_PMCI);
 183
 184                 mpc6xx_enter_standby();
 185         }
 186
 187         ret = 0;
 188
 189 out:
 190         out_be32(&pmc_regs->config1,
 191                  in_be32(&pmc_regs->config1) & ~PMCCR1_PME_EN);
 192
 193         return ret;
 194 }
 195
 196 static void mpc83xx_suspend_finish(void)
 197 {
 198         deep_sleeping = 0;
 199 }
 200
 201 static int mpc83xx_suspend_valid(suspend_state_t state)
 202 {
 203         return state == PM_SUSPEND_STANDBY || state == PM_SUSPEND_MEM;
 204 }
 205
 206 static int mpc83xx_suspend_begin(suspend_state_t state)
 207 {
 208         switch (state) {
 209                 case PM_SUSPEND_STANDBY:
 210                         deep_sleeping = 0;
 211                         return 0;
 212
 213                 case PM_SUSPEND_MEM:
 214                         if (has_deep_sleep)
 215                                 deep_sleeping = 1;
 216
 217                         return 0;
 218
 219                 default:
 220                         return -EINVAL;
 221         }
 222 }
 223
 224 static int agent_thread_fn(void *data)
 225 {
 226         while (1) {
 227                 wait_event_interruptible(agent_wq, pci_pm_state >= 2);
 228                 try_to_freeze();
 229
 230                 if (signal_pending(current) || pci_pm_state < 2)
 231                         continue;
 232
 233                 /* With a preemptible kernel (or SMP), this could race with
 234                  * a userspace-driven suspend request.  It's probably best
 235                  * to avoid mixing the two with such a configuration (or
 236                  * else fix it by adding a mutex to state_store that we can
 237                  * synchronize with).
 238                  */
 239
 240                 wake_from_pci = 1;
 241
 242                 pm_suspend(pci_pm_state == 3 ? PM_SUSPEND_MEM :
 243                                                PM_SUSPEND_STANDBY);
 244
 245                 wake_from_pci = 0;
 246         }
 247
 248         return 0;
 249 }
 250
 251 static void mpc83xx_set_agent(void)
 252 {
 253         out_be32(&pmc_regs->config1, PMCCR1_USE_STATE);
 254         out_be32(&pmc_regs->mask, PMCER_PMCI);
 255
 256         kthread_run(agent_thread_fn, NULL, "PCI power mgt");
 257 }
 258
 259 static int mpc83xx_is_pci_agent(void)
 260 {
 261         struct mpc83xx_rcw __iomem *rcw_regs;
 262         int ret;
 263
 264         rcw_regs = ioremap(get_immrbase() + IMMR_RCW_OFFSET,
 265                            sizeof(struct mpc83xx_rcw));
 266
 267         if (!rcw_regs)
 268                 return -ENOMEM;
 269
 270         ret = !(in_be32(&rcw_regs->rcwhr) & RCW_PCI_HOST);
 271
 272         iounmap(rcw_regs);
 273         return ret;
 274 }
 275
 276 static struct platform_suspend_ops mpc83xx_suspend_ops = {
 277         .valid = mpc83xx_suspend_valid,
 278         .begin = mpc83xx_suspend_begin,
 279         .enter = mpc83xx_suspend_enter,
 280         .finish = mpc83xx_suspend_finish,
 281 };
 282
 283 static int pmc_probe(struct of_device *ofdev,
 284                      const struct of_device_id *match)
 285 {
 286         struct device_node *np = ofdev->node;
 287         struct resource res;
 288         struct pmc_type *type = match->data;
 289         int ret = 0;
 290
 291         if (!of_device_is_available(np))
 292                 return -ENODEV;
 293
 294         has_deep_sleep = type->has_deep_sleep;
 295         immrbase = get_immrbase();
 296         pmc_dev = ofdev;
 297
 298         is_pci_agent = mpc83xx_is_pci_agent();
 299         if (is_pci_agent < 0)
 300                 return is_pci_agent;
 301
 302         ret = of_address_to_resource(np, 0, &res);
 303         if (ret)
 304                 return -ENODEV;
 305
 306         pmc_irq = irq_of_parse_and_map(np, 0);
 307         if (pmc_irq != NO_IRQ) {
 308                 ret = request_irq(pmc_irq, pmc_irq_handler, IRQF_SHARED,
 309                                   "pmc", ofdev);
 310
 311                 if (ret)
 312                         return -EBUSY;
 313         }
 314
 315         pmc_regs = ioremap(res.start, sizeof(struct mpc83xx_pmc));
 316
 317         if (!pmc_regs) {
 318                 ret = -ENOMEM;
 319                 goto out;
 320         }
 321
 322         ret = of_address_to_resource(np, 1, &res);
 323         if (ret) {
 324                 ret = -ENODEV;
 325                 goto out_pmc;
 326         }
 327
 328         clock_regs = ioremap(res.start, sizeof(struct mpc83xx_pmc));
 329
 330         if (!clock_regs) {
 331                 ret = -ENOMEM;
 332                 goto out_pmc;
 333         }
 334
 335         if (is_pci_agent)
 336                 mpc83xx_set_agent();
 337
 338         suspend_set_ops(&mpc83xx_suspend_ops);
 339         return 0;
 340
 341 out_pmc:
 342         iounmap(pmc_regs);
 343 out:
 344         if (pmc_irq != NO_IRQ)
 345                 free_irq(pmc_irq, ofdev);
 346
 347         return ret;
 348 }
 349
 350 static int pmc_remove(struct of_device *ofdev)
 351 {
 352         return -EPERM;
 353 };
 354
 355 static struct pmc_type pmc_types[] = {
 356         {
 357                 .has_deep_sleep = 1,
 358         },
 359         {
 360                 .has_deep_sleep = 0,
 361         }
 362 };
 363
 364 static struct of_device_id pmc_match[] = {
 365         {
 366                 .compatible = "fsl,mpc8313-pmc",
 367                 .data = &pmc_types[0],
 368         },
 369         {
 370                 .compatible = "fsl,mpc8349-pmc",
 371                 .data = &pmc_types[1],
 372         },
 373         {}
 374 };
 375
 376 static struct of_platform_driver pmc_driver = {
 377         .name = "mpc83xx-pmc",
 378         .match_table = pmc_match,
 379         .probe = pmc_probe,
 380         .remove = pmc_remove
 381 };
 382
 383 static int pmc_init(void)
 384 {
 385         return of_register_platform_driver(&pmc_driver);
 386 }
 387
 388 module_init(pmc_init);