arch/arm/plat-samsung/pm.c

   1 /* linux/arch/arm/plat-s3c/pm.c
   2  *
   3  * Copyright 2008 Openmoko, Inc.
   4  * Copyright 2004-2008 Simtec Electronics
   5  *      Ben Dooks <ben@simtec.co.uk>
   6  *      http://armlinux.simtec.co.uk/
   7  *
   8  * S3C common power management (suspend to ram) support.
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2 as
  12  * published by the Free Software Foundation.
  13 */
  14
  15 #include <linux/init.h>
  16 #include <linux/suspend.h>
  17 #include <linux/errno.h>
  18 #include <linux/delay.h>
  19 #include <linux/of.h>
  20 #include <linux/serial_core.h>
  21 #include <linux/io.h>
  22
  23 #include <asm/cacheflush.h>
  24 #include <asm/suspend.h>
  25
  26 #include <plat/regs-serial.h>
  27
  28 #ifdef CONFIG_SAMSUNG_ATAGS
  29 #include <mach/hardware.h>
  30 #include <mach/map.h>
  31 #include <mach/regs-clock.h>
  32 #include <mach/regs-irq.h>
  33 #include <mach/irqs.h>
  34 #endif
  35
  36 #include <asm/irq.h>
  37
  38 #include <plat/pm.h>
  39 #include <mach/pm-core.h>
  40
  41 /* for external use */
  42
  43 unsigned long s3c_pm_flags;
  44
  45 /* Debug code:
  46  *
  47  * This code supports debug output to the low level UARTs for use on
  48  * resume before the console layer is available.
  49 */
  50
  51 #ifdef CONFIG_SAMSUNG_PM_DEBUG
  52 extern void printascii(const char *);
  53
  54 void s3c_pm_dbg(const char *fmt, ...)
  55 {
  56         va_list va;
  57         char buff[256];
  58
  59         va_start(va, fmt);
  60         vsnprintf(buff, sizeof(buff), fmt, va);
  61         va_end(va);
  62
  63         printascii(buff);
  64 }
  65
  66 static inline void s3c_pm_debug_init(void)
  67 {
  68         /* restart uart clocks so we can use them to output */
  69         s3c_pm_debug_init_uart();
  70 }
  71
  72 #else
  73 #define s3c_pm_debug_init() do { } while(0)
  74
  75 #endif /* CONFIG_SAMSUNG_PM_DEBUG */
  76
  77 /* Save the UART configurations if we are configured for debug. */
  78
  79 unsigned char pm_uart_udivslot;
  80
  81 #ifdef CONFIG_SAMSUNG_PM_DEBUG
  82
  83 static struct pm_uart_save uart_save;
  84
  85 static void s3c_pm_save_uart(unsigned int uart, struct pm_uart_save *save)
  86 {
  87         void __iomem *regs = S3C_VA_UARTx(uart);
  88
  89         save->ulcon = __raw_readl(regs + S3C2410_ULCON);
  90         save->ucon = __raw_readl(regs + S3C2410_UCON);
  91         save->ufcon = __raw_readl(regs + S3C2410_UFCON);
  92         save->umcon = __raw_readl(regs + S3C2410_UMCON);
  93         save->ubrdiv = __raw_readl(regs + S3C2410_UBRDIV);
  94
  95         if (pm_uart_udivslot)
  96                 save->udivslot = __raw_readl(regs + S3C2443_DIVSLOT);
  97
  98         S3C_PMDBG("UART[%d]: ULCON=%04x, UCON=%04x, UFCON=%04x, UBRDIV=%04x\n",
  99                   uart, save->ulcon, save->ucon, save->ufcon, save->ubrdiv);
 100 }
 101
 102 static void s3c_pm_save_uarts(void)
 103 {
 104         s3c_pm_save_uart(CONFIG_DEBUG_S3C_UART, &uart_save);
 105 }
 106
 107 static void s3c_pm_restore_uart(unsigned int uart, struct pm_uart_save *save)
 108 {
 109         void __iomem *regs = S3C_VA_UARTx(uart);
 110
 111         s3c_pm_arch_update_uart(regs, save);
 112
 113         __raw_writel(save->ulcon, regs + S3C2410_ULCON);
 114         __raw_writel(save->ucon,  regs + S3C2410_UCON);
 115         __raw_writel(save->ufcon, regs + S3C2410_UFCON);
 116         __raw_writel(save->umcon, regs + S3C2410_UMCON);
 117         __raw_writel(save->ubrdiv, regs + S3C2410_UBRDIV);
 118
 119         if (pm_uart_udivslot)
 120                 __raw_writel(save->udivslot, regs + S3C2443_DIVSLOT);
 121 }
 122
 123 static void s3c_pm_restore_uarts(void)
 124 {
 125         s3c_pm_restore_uart(CONFIG_DEBUG_S3C_UART, &uart_save);
 126 }
 127 #else
 128 static void s3c_pm_save_uarts(void) { }
 129 static void s3c_pm_restore_uarts(void) { }
 130 #endif
 131
 132 /* The IRQ ext-int code goes here, it is too small to currently bother
 133  * with its own file. */
 134
 135 unsigned long s3c_irqwake_intmask       = 0xffffffffL;
 136 unsigned long s3c_irqwake_eintmask      = 0xffffffffL;
 137
 138 int s3c_irqext_wake(struct irq_data *data, unsigned int state)
 139 {
 140         unsigned long bit = 1L << IRQ_EINT_BIT(data->irq);
 141
 142         if (!(s3c_irqwake_eintallow & bit))
 143                 return -ENOENT;
 144
 145         printk(KERN_INFO "wake %s for irq %d\n",
 146                state ? "enabled" : "disabled", data->irq);
 147
 148         if (!state)
 149                 s3c_irqwake_eintmask |= bit;
 150         else
 151                 s3c_irqwake_eintmask &= ~bit;
 152
 153         return 0;
 154 }
 155
 156 /* helper functions to save and restore register state */
 157
 158 /**
 159  * s3c_pm_do_save() - save a set of registers for restoration on resume.
 160  * @ptr: Pointer to an array of registers.
 161  * @count: Size of the ptr array.
 162  *
 163  * Run through the list of registers given, saving their contents in the
 164  * array for later restoration when we wakeup.
 165  */
 166 void s3c_pm_do_save(struct sleep_save *ptr, int count)
 167 {
 168         for (; count > 0; count--, ptr++) {
 169                 ptr->val = __raw_readl(ptr->reg);
 170                 S3C_PMDBG("saved %p value %08lx\n", ptr->reg, ptr->val);
 171         }
 172 }
 173
 174 /**
 175  * s3c_pm_do_restore() - restore register values from the save list.
 176  * @ptr: Pointer to an array of registers.
 177  * @count: Size of the ptr array.
 178  *
 179  * Restore the register values saved from s3c_pm_do_save().
 180  *
 181  * Note, we do not use S3C_PMDBG() in here, as the system may not have
 182  * restore the UARTs state yet
 183 */
 184
 185 void s3c_pm_do_restore(struct sleep_save *ptr, int count)
 186 {
 187         for (; count > 0; count--, ptr++) {
 188                 printk(KERN_DEBUG "restore %p (restore %08lx, was %08x)\n",
 189                        ptr->reg, ptr->val, __raw_readl(ptr->reg));
 190
 191                 __raw_writel(ptr->val, ptr->reg);
 192         }
 193 }
 194
 195 /**
 196  * s3c_pm_do_restore_core() - early restore register values from save list.
 197  *
 198  * This is similar to s3c_pm_do_restore() except we try and minimise the
 199  * side effects of the function in case registers that hardware might need
 200  * to work has been restored.
 201  *
 202  * WARNING: Do not put any debug in here that may effect memory or use
 203  * peripherals, as things may be changing!
 204 */
 205
 206 void s3c_pm_do_restore_core(struct sleep_save *ptr, int count)
 207 {
 208         for (; count > 0; count--, ptr++)
 209                 __raw_writel(ptr->val, ptr->reg);
 210 }
 211
 212 /* s3c2410_pm_show_resume_irqs
 213  *
 214  * print any IRQs asserted at resume time (ie, we woke from)
 215 */
 216 static void __maybe_unused s3c_pm_show_resume_irqs(int start,
 217                                                    unsigned long which,
 218                                                    unsigned long mask)
 219 {
 220         int i;
 221
 222         which &= ~mask;
 223
 224         for (i = 0; i <= 31; i++) {
 225                 if (which & (1L<<i)) {
 226                         S3C_PMDBG("IRQ %d asserted at resume\n", start+i);
 227                 }
 228         }
 229 }
 230
 231
 232 void (*pm_cpu_prep)(void);
 233 int (*pm_cpu_sleep)(unsigned long);
 234
 235 #define any_allowed(mask, allow) (((mask) & (allow)) != (allow))
 236
 237 /* s3c_pm_enter
 238  *
 239  * central control for sleep/resume process
 240 */
 241
 242 static int s3c_pm_enter(suspend_state_t state)
 243 {
 244         int ret;
 245         /* ensure the debug is initialised (if enabled) */
 246
 247         s3c_pm_debug_init();
 248
 249         S3C_PMDBG("%s(%d)\n", __func__, state);
 250
 251         if (pm_cpu_prep == NULL || pm_cpu_sleep == NULL) {
 252                 printk(KERN_ERR "%s: error: no cpu sleep function\n", __func__);
 253                 return -EINVAL;
 254         }
 255
 256         /* check if we have anything to wake-up with... bad things seem
 257          * to happen if you suspend with no wakeup (system will often
 258          * require a full power-cycle)
 259         */
 260
 261         if (!of_have_populated_dt() &&
 262             !any_allowed(s3c_irqwake_intmask, s3c_irqwake_intallow) &&
 263             !any_allowed(s3c_irqwake_eintmask, s3c_irqwake_eintallow)) {
 264                 printk(KERN_ERR "%s: No wake-up sources!\n", __func__);
 265                 printk(KERN_ERR "%s: Aborting sleep\n", __func__);
 266                 return -EINVAL;
 267         }
 268
 269         /* save all necessary core registers not covered by the drivers */
 270
 271         if (!of_have_populated_dt()) {
 272                 samsung_pm_save_gpios();
 273                 samsung_pm_saved_gpios();
 274         }
 275
 276         s3c_pm_save_uarts();
 277         s3c_pm_save_core();
 278
 279         /* set the irq configuration for wake */
 280
 281         s3c_pm_configure_extint();
 282
 283         S3C_PMDBG("sleep: irq wakeup masks: %08lx,%08lx\n",
 284             s3c_irqwake_intmask, s3c_irqwake_eintmask);
 285
 286         s3c_pm_arch_prepare_irqs();
 287
 288         /* call cpu specific preparation */
 289
 290         pm_cpu_prep();
 291
 292         /* flush cache back to ram */
 293
 294         flush_cache_all();
 295
 296         s3c_pm_check_store();
 297
 298         /* send the cpu to sleep... */
 299
 300         s3c_pm_arch_stop_clocks();
 301
 302         /* this will also act as our return point from when
 303          * we resume as it saves its own register state and restores it
 304          * during the resume.  */
 305
 306         ret = cpu_suspend(0, pm_cpu_sleep);
 307         if (ret)
 308                 return ret;
 309
 310         /* restore the system state */
 311
 312         s3c_pm_restore_core();
 313         s3c_pm_restore_uarts();
 314
 315         if (!of_have_populated_dt()) {
 316                 samsung_pm_restore_gpios();
 317                 s3c_pm_restored_gpios();
 318         }
 319
 320         s3c_pm_debug_init();
 321
 322         /* check what irq (if any) restored the system */
 323
 324         s3c_pm_arch_show_resume_irqs();
 325
 326         S3C_PMDBG("%s: post sleep, preparing to return\n", __func__);
 327
 328         /* LEDs should now be 1110 */
 329         s3c_pm_debug_smdkled(1 << 1, 0);
 330
 331         s3c_pm_check_restore();
 332
 333         /* ok, let's return from sleep */
 334
 335         S3C_PMDBG("S3C PM Resume (post-restore)\n");
 336         return 0;
 337 }
 338
 339 static int s3c_pm_prepare(void)
 340 {
 341         /* prepare check area if configured */
 342
 343         s3c_pm_check_prepare();
 344         return 0;
 345 }
 346
 347 static void s3c_pm_finish(void)
 348 {
 349         s3c_pm_check_cleanup();
 350 }
 351
 352 static const struct platform_suspend_ops s3c_pm_ops = {
 353         .enter          = s3c_pm_enter,
 354         .prepare        = s3c_pm_prepare,
 355         .finish         = s3c_pm_finish,
 356         .valid          = suspend_valid_only_mem,
 357 };
 358
 359 /* s3c_pm_init
 360  *
 361  * Attach the power management functions. This should be called
 362  * from the board specific initialisation if the board supports
 363  * it.
 364 */
 365
 366 int __init s3c_pm_init(void)
 367 {
 368         printk("S3C Power Management, Copyright 2004 Simtec Electronics\n");
 369
 370         suspend_set_ops(&s3c_pm_ops);
 371         return 0;
 372 }