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 #include <mach/hardware.h>
  26 #include <mach/map.h>
  27
  28 #include <plat/regs-serial.h>
  29 #include <mach/regs-clock.h>
  30 #include <mach/regs-irq.h>
  31 #include <mach/irqs.h>
  32 #include <asm/irq.h>
  33
  34 #include <plat/pm.h>
  35 #include <mach/pm-core.h>
  36
  37 /* for external use */
  38
  39 unsigned long s3c_pm_flags;
  40
  41 /* Debug code:
  42  *
  43  * This code supports debug output to the low level UARTs for use on
  44  * resume before the console layer is available.
  45 */
  46
  47 #ifdef CONFIG_SAMSUNG_PM_DEBUG
  48 extern void printascii(const char *);
  49
  50 void s3c_pm_dbg(const char *fmt, ...)
  51 {
  52         va_list va;
  53         char buff[256];
  54
  55         va_start(va, fmt);
  56         vsnprintf(buff, sizeof(buff), fmt, va);
  57         va_end(va);
  58
  59         printascii(buff);
  60 }
  61
  62 static inline void s3c_pm_debug_init(void)
  63 {
  64         /* restart uart clocks so we can use them to output */
  65         s3c_pm_debug_init_uart();
  66 }
  67
  68 #else
  69 #define s3c_pm_debug_init() do { } while(0)
  70
  71 #endif /* CONFIG_SAMSUNG_PM_DEBUG */
  72
  73 /* Save the UART configurations if we are configured for debug. */
  74
  75 unsigned char pm_uart_udivslot;
  76
  77 #ifdef CONFIG_SAMSUNG_PM_DEBUG
  78
  79 static struct pm_uart_save uart_save[CONFIG_SERIAL_SAMSUNG_UARTS];
  80
  81 static void s3c_pm_save_uart(unsigned int uart, struct pm_uart_save *save)
  82 {
  83         void __iomem *regs = S3C_VA_UARTx(uart);
  84
  85         save->ulcon = __raw_readl(regs + S3C2410_ULCON);
  86         save->ucon = __raw_readl(regs + S3C2410_UCON);
  87         save->ufcon = __raw_readl(regs + S3C2410_UFCON);
  88         save->umcon = __raw_readl(regs + S3C2410_UMCON);
  89         save->ubrdiv = __raw_readl(regs + S3C2410_UBRDIV);
  90
  91         if (pm_uart_udivslot)
  92                 save->udivslot = __raw_readl(regs + S3C2443_DIVSLOT);
  93
  94         S3C_PMDBG("UART[%d]: ULCON=%04x, UCON=%04x, UFCON=%04x, UBRDIV=%04x\n",
  95                   uart, save->ulcon, save->ucon, save->ufcon, save->ubrdiv);
  96 }
  97
  98 static void s3c_pm_save_uarts(void)
  99 {
 100         struct pm_uart_save *save = uart_save;
 101         unsigned int uart;
 102
 103         for (uart = 0; uart < CONFIG_SERIAL_SAMSUNG_UARTS; uart++, save++)
 104                 s3c_pm_save_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         struct pm_uart_save *save = uart_save;
 126         unsigned int uart;
 127
 128         for (uart = 0; uart < CONFIG_SERIAL_SAMSUNG_UARTS; uart++, save++)
 129                 s3c_pm_restore_uart(uart, save);
 130 }
 131 #else
 132 static void s3c_pm_save_uarts(void) { }
 133 static void s3c_pm_restore_uarts(void) { }
 134 #endif
 135
 136 /* The IRQ ext-int code goes here, it is too small to currently bother
 137  * with its own file. */
 138
 139 unsigned long s3c_irqwake_intmask       = 0xffffffffL;
 140 unsigned long s3c_irqwake_eintmask      = 0xffffffffL;
 141
 142 int s3c_irqext_wake(struct irq_data *data, unsigned int state)
 143 {
 144         unsigned long bit = 1L << IRQ_EINT_BIT(data->irq);
 145
 146         if (!(s3c_irqwake_eintallow & bit))
 147                 return -ENOENT;
 148
 149         printk(KERN_INFO "wake %s for irq %d\n",
 150                state ? "enabled" : "disabled", data->irq);
 151
 152         if (!state)
 153                 s3c_irqwake_eintmask |= bit;
 154         else
 155                 s3c_irqwake_eintmask &= ~bit;
 156
 157         return 0;
 158 }
 159
 160 /* helper functions to save and restore register state */
 161
 162 /**
 163  * s3c_pm_do_save() - save a set of registers for restoration on resume.
 164  * @ptr: Pointer to an array of registers.
 165  * @count: Size of the ptr array.
 166  *
 167  * Run through the list of registers given, saving their contents in the
 168  * array for later restoration when we wakeup.
 169  */
 170 void s3c_pm_do_save(struct sleep_save *ptr, int count)
 171 {
 172         for (; count > 0; count--, ptr++) {
 173                 ptr->val = __raw_readl(ptr->reg);
 174                 S3C_PMDBG("saved %p value %08lx\n", ptr->reg, ptr->val);
 175         }
 176 }
 177
 178 /**
 179  * s3c_pm_do_restore() - restore register values from the save list.
 180  * @ptr: Pointer to an array of registers.
 181  * @count: Size of the ptr array.
 182  *
 183  * Restore the register values saved from s3c_pm_do_save().
 184  *
 185  * Note, we do not use S3C_PMDBG() in here, as the system may not have
 186  * restore the UARTs state yet
 187 */
 188
 189 void s3c_pm_do_restore(struct sleep_save *ptr, int count)
 190 {
 191         for (; count > 0; count--, ptr++) {
 192                 printk(KERN_DEBUG "restore %p (restore %08lx, was %08x)\n",
 193                        ptr->reg, ptr->val, __raw_readl(ptr->reg));
 194
 195                 __raw_writel(ptr->val, ptr->reg);
 196         }
 197 }
 198
 199 /**
 200  * s3c_pm_do_restore_core() - early restore register values from save list.
 201  *
 202  * This is similar to s3c_pm_do_restore() except we try and minimise the
 203  * side effects of the function in case registers that hardware might need
 204  * to work has been restored.
 205  *
 206  * WARNING: Do not put any debug in here that may effect memory or use
 207  * peripherals, as things may be changing!
 208 */
 209
 210 void s3c_pm_do_restore_core(struct sleep_save *ptr, int count)
 211 {
 212         for (; count > 0; count--, ptr++)
 213                 __raw_writel(ptr->val, ptr->reg);
 214 }
 215
 216 /* s3c2410_pm_show_resume_irqs
 217  *
 218  * print any IRQs asserted at resume time (ie, we woke from)
 219 */
 220 static void __maybe_unused s3c_pm_show_resume_irqs(int start,
 221                                                    unsigned long which,
 222                                                    unsigned long mask)
 223 {
 224         int i;
 225
 226         which &= ~mask;
 227
 228         for (i = 0; i <= 31; i++) {
 229                 if (which & (1L<<i)) {
 230                         S3C_PMDBG("IRQ %d asserted at resume\n", start+i);
 231                 }
 232         }
 233 }
 234
 235
 236 void (*pm_cpu_prep)(void);
 237 int (*pm_cpu_sleep)(unsigned long);
 238
 239 #define any_allowed(mask, allow) (((mask) & (allow)) != (allow))
 240
 241 /* s3c_pm_enter
 242  *
 243  * central control for sleep/resume process
 244 */
 245
 246 static int s3c_pm_enter(suspend_state_t state)
 247 {
 248         int ret;
 249         /* ensure the debug is initialised (if enabled) */
 250
 251         s3c_pm_debug_init();
 252
 253         S3C_PMDBG("%s(%d)\n", __func__, state);
 254
 255         if (pm_cpu_prep == NULL || pm_cpu_sleep == NULL) {
 256                 printk(KERN_ERR "%s: error: no cpu sleep function\n", __func__);
 257                 return -EINVAL;
 258         }
 259
 260         /* check if we have anything to wake-up with... bad things seem
 261          * to happen if you suspend with no wakeup (system will often
 262          * require a full power-cycle)
 263         */
 264
 265         if (!of_have_populated_dt() &&
 266             !any_allowed(s3c_irqwake_intmask, s3c_irqwake_intallow) &&
 267             !any_allowed(s3c_irqwake_eintmask, s3c_irqwake_eintallow)) {
 268                 printk(KERN_ERR "%s: No wake-up sources!\n", __func__);
 269                 printk(KERN_ERR "%s: Aborting sleep\n", __func__);
 270                 return -EINVAL;
 271         }
 272
 273         /* save all necessary core registers not covered by the drivers */
 274
 275         if (!of_have_populated_dt()) {
 276                 samsung_pm_save_gpios();
 277                 samsung_pm_saved_gpios();
 278         }
 279
 280         s3c_pm_save_uarts();
 281         s3c_pm_save_core();
 282
 283         /* set the irq configuration for wake */
 284
 285         s3c_pm_configure_extint();
 286
 287         S3C_PMDBG("sleep: irq wakeup masks: %08lx,%08lx\n",
 288             s3c_irqwake_intmask, s3c_irqwake_eintmask);
 289
 290         s3c_pm_arch_prepare_irqs();
 291
 292         /* call cpu specific preparation */
 293
 294         pm_cpu_prep();
 295
 296         /* flush cache back to ram */
 297
 298         flush_cache_all();
 299
 300         s3c_pm_check_store();
 301
 302         /* send the cpu to sleep... */
 303
 304         s3c_pm_arch_stop_clocks();
 305
 306         /* this will also act as our return point from when
 307          * we resume as it saves its own register state and restores it
 308          * during the resume.  */
 309
 310         ret = cpu_suspend(0, pm_cpu_sleep);
 311         if (ret)
 312                 return ret;
 313
 314         /* restore the system state */
 315
 316         s3c_pm_restore_core();
 317         s3c_pm_restore_uarts();
 318
 319         if (!of_have_populated_dt()) {
 320                 samsung_pm_restore_gpios();
 321                 s3c_pm_restored_gpios();
 322         }
 323
 324         s3c_pm_debug_init();
 325
 326         /* check what irq (if any) restored the system */
 327
 328         s3c_pm_arch_show_resume_irqs();
 329
 330         S3C_PMDBG("%s: post sleep, preparing to return\n", __func__);
 331
 332         /* LEDs should now be 1110 */
 333         s3c_pm_debug_smdkled(1 << 1, 0);
 334
 335         s3c_pm_check_restore();
 336
 337         /* ok, let's return from sleep */
 338
 339         S3C_PMDBG("S3C PM Resume (post-restore)\n");
 340         return 0;
 341 }
 342
 343 static int s3c_pm_prepare(void)
 344 {
 345         /* prepare check area if configured */
 346
 347         s3c_pm_check_prepare();
 348         return 0;
 349 }
 350
 351 static void s3c_pm_finish(void)
 352 {
 353         s3c_pm_check_cleanup();
 354 }
 355
 356 static const struct platform_suspend_ops s3c_pm_ops = {
 357         .enter          = s3c_pm_enter,
 358         .prepare        = s3c_pm_prepare,
 359         .finish         = s3c_pm_finish,
 360         .valid          = suspend_valid_only_mem,
 361 };
 362
 363 /* s3c_pm_init
 364  *
 365  * Attach the power management functions. This should be called
 366  * from the board specific initialisation if the board supports
 367  * it.
 368 */
 369
 370 int __init s3c_pm_init(void)
 371 {
 372         printk("S3C Power Management, Copyright 2004 Simtec Electronics\n");
 373
 374         suspend_set_ops(&s3c_pm_ops);
 375         return 0;
 376 }