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