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 <asm/irq.h>
  31
  32 #include <plat/pm.h>
  33 #include <mach/pm-core.h>
  34
  35 /* for external use */
  36
  37 unsigned long s3c_pm_flags;
  38
  39 /* Debug code:
  40  *
  41  * This code supports debug output to the low level UARTs for use on
  42  * resume before the console layer is available.
  43 */
  44
  45 #ifdef CONFIG_SAMSUNG_PM_DEBUG
  46 extern void printascii(const char *);
  47
  48 void s3c_pm_dbg(const char *fmt, ...)
  49 {
  50         va_list va;
  51         char buff[256];
  52
  53         va_start(va, fmt);
  54         vsprintf(buff, fmt, va);
  55         va_end(va);
  56
  57         printascii(buff);
  58 }
  59
  60 static inline void s3c_pm_debug_init(void)
  61 {
  62         /* restart uart clocks so we can use them to output */
  63         s3c_pm_debug_init_uart();
  64 }
  65
  66 #else
  67 #define s3c_pm_debug_init() do { } while(0)
  68
  69 #endif /* CONFIG_SAMSUNG_PM_DEBUG */
  70
  71 /* Save the UART configurations if we are configured for debug. */
  72
  73 unsigned char pm_uart_udivslot;
  74
  75 #ifdef CONFIG_SAMSUNG_PM_DEBUG
  76
  77 struct pm_uart_save uart_save[CONFIG_SERIAL_SAMSUNG_UARTS];
  78
  79 static void s3c_pm_save_uart(unsigned int uart, struct pm_uart_save *save)
  80 {
  81         void __iomem *regs = S3C_VA_UARTx(uart);
  82
  83         save->ulcon = __raw_readl(regs + S3C2410_ULCON);
  84         save->ucon = __raw_readl(regs + S3C2410_UCON);
  85         save->ufcon = __raw_readl(regs + S3C2410_UFCON);
  86         save->umcon = __raw_readl(regs + S3C2410_UMCON);
  87         save->ubrdiv = __raw_readl(regs + S3C2410_UBRDIV);
  88
  89         if (pm_uart_udivslot)
  90                 save->udivslot = __raw_readl(regs + S3C2443_DIVSLOT);
  91
  92         S3C_PMDBG("UART[%d]: ULCON=%04x, UCON=%04x, UFCON=%04x, UBRDIV=%04x\n",
  93                   uart, save->ulcon, save->ucon, save->ufcon, save->ubrdiv);
  94 }
  95
  96 static void s3c_pm_save_uarts(void)
  97 {
  98         struct pm_uart_save *save = uart_save;
  99         unsigned int uart;
 100
 101         for (uart = 0; uart < CONFIG_SERIAL_SAMSUNG_UARTS; uart++, save++)
 102                 s3c_pm_save_uart(uart, save);
 103 }
 104
 105 static void s3c_pm_restore_uart(unsigned int uart, struct pm_uart_save *save)
 106 {
 107         void __iomem *regs = S3C_VA_UARTx(uart);
 108
 109         s3c_pm_arch_update_uart(regs, save);
 110
 111         __raw_writel(save->ulcon, regs + S3C2410_ULCON);
 112         __raw_writel(save->ucon,  regs + S3C2410_UCON);
 113         __raw_writel(save->ufcon, regs + S3C2410_UFCON);
 114         __raw_writel(save->umcon, regs + S3C2410_UMCON);
 115         __raw_writel(save->ubrdiv, regs + S3C2410_UBRDIV);
 116
 117         if (pm_uart_udivslot)
 118                 __raw_writel(save->udivslot, regs + S3C2443_DIVSLOT);
 119 }
 120
 121 static void s3c_pm_restore_uarts(void)
 122 {
 123         struct pm_uart_save *save = uart_save;
 124         unsigned int uart;
 125
 126         for (uart = 0; uart < CONFIG_SERIAL_SAMSUNG_UARTS; uart++, save++)
 127                 s3c_pm_restore_uart(uart, save);
 128 }
 129 #else
 130 static void s3c_pm_save_uarts(void) { }
 131 static void s3c_pm_restore_uarts(void) { }
 132 #endif
 133
 134 /* The IRQ ext-int code goes here, it is too small to currently bother
 135  * with its own file. */
 136
 137 unsigned long s3c_irqwake_intmask       = 0xffffffffL;
 138 unsigned long s3c_irqwake_eintmask      = 0xffffffffL;
 139
 140 int s3c_irqext_wake(struct irq_data *data, unsigned int state)
 141 {
 142         unsigned long bit = 1L << IRQ_EINT_BIT(data->irq);
 143
 144         if (!(s3c_irqwake_eintallow & bit))
 145                 return -ENOENT;
 146
 147         printk(KERN_INFO "wake %s for irq %d\n",
 148                state ? "enabled" : "disabled", data->irq);
 149
 150         if (!state)
 151                 s3c_irqwake_eintmask |= bit;
 152         else
 153                 s3c_irqwake_eintmask &= ~bit;
 154
 155         return 0;
 156 }
 157
 158 /* helper functions to save and restore register state */
 159
 160 /**
 161  * s3c_pm_do_save() - save a set of registers for restoration on resume.
 162  * @ptr: Pointer to an array of registers.
 163  * @count: Size of the ptr array.
 164  *
 165  * Run through the list of registers given, saving their contents in the
 166  * array for later restoration when we wakeup.
 167  */
 168 void s3c_pm_do_save(struct sleep_save *ptr, int count)
 169 {
 170         for (; count > 0; count--, ptr++) {
 171                 ptr->val = __raw_readl(ptr->reg);
 172                 S3C_PMDBG("saved %p value %08lx\n", ptr->reg, ptr->val);
 173         }
 174 }
 175
 176 /**
 177  * s3c_pm_do_restore() - restore register values from the save list.
 178  * @ptr: Pointer to an array of registers.
 179  * @count: Size of the ptr array.
 180  *
 181  * Restore the register values saved from s3c_pm_do_save().
 182  *
 183  * Note, we do not use S3C_PMDBG() in here, as the system may not have
 184  * restore the UARTs state yet
 185 */
 186
 187 void s3c_pm_do_restore(struct sleep_save *ptr, int count)
 188 {
 189         for (; count > 0; count--, ptr++) {
 190                 printk(KERN_DEBUG "restore %p (restore %08lx, was %08x)\n",
 191                        ptr->reg, ptr->val, __raw_readl(ptr->reg));
 192
 193                 __raw_writel(ptr->val, ptr->reg);
 194         }
 195 }
 196
 197 /**
 198  * s3c_pm_do_restore_core() - early restore register values from save list.
 199  *
 200  * This is similar to s3c_pm_do_restore() except we try and minimise the
 201  * side effects of the function in case registers that hardware might need
 202  * to work has been restored.
 203  *
 204  * WARNING: Do not put any debug in here that may effect memory or use
 205  * peripherals, as things may be changing!
 206 */
 207
 208 void s3c_pm_do_restore_core(struct sleep_save *ptr, int count)
 209 {
 210         for (; count > 0; count--, ptr++)
 211                 __raw_writel(ptr->val, ptr->reg);
 212 }
 213
 214 /* s3c2410_pm_show_resume_irqs
 215  *
 216  * print any IRQs asserted at resume time (ie, we woke from)
 217 */
 218 static void __maybe_unused s3c_pm_show_resume_irqs(int start,
 219                                                    unsigned long which,
 220                                                    unsigned long mask)
 221 {
 222         int i;
 223
 224         which &= ~mask;
 225
 226         for (i = 0; i <= 31; i++) {
 227                 if (which & (1L<<i)) {
 228                         S3C_PMDBG("IRQ %d asserted at resume\n", start+i);
 229                 }
 230         }
 231 }
 232
 233
 234 void (*pm_cpu_prep)(void);
 235 int (*pm_cpu_sleep)(unsigned long);
 236
 237 #define any_allowed(mask, allow) (((mask) & (allow)) != (allow))
 238
 239 /* s3c_pm_enter
 240  *
 241  * central control for sleep/resume process
 242 */
 243
 244 static int s3c_pm_enter(suspend_state_t state)
 245 {
 246         /* ensure the debug is initialised (if enabled) */
 247
 248         s3c_pm_debug_init();
 249
 250         S3C_PMDBG("%s(%d)\n", __func__, state);
 251
 252         if (pm_cpu_prep == NULL || pm_cpu_sleep == NULL) {
 253                 printk(KERN_ERR "%s: error: no cpu sleep function\n", __func__);
 254                 return -EINVAL;
 255         }
 256
 257         /* check if we have anything to wake-up with... bad things seem
 258          * to happen if you suspend with no wakeup (system will often
 259          * require a full power-cycle)
 260         */
 261
 262         if (!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         s3c_pm_save_gpios();
 272         s3c_pm_saved_gpios();
 273         s3c_pm_save_uarts();
 274         s3c_pm_save_core();
 275
 276         /* set the irq configuration for wake */
 277
 278         s3c_pm_configure_extint();
 279
 280         S3C_PMDBG("sleep: irq wakeup masks: %08lx,%08lx\n",
 281             s3c_irqwake_intmask, s3c_irqwake_eintmask);
 282
 283         s3c_pm_arch_prepare_irqs();
 284
 285         /* call cpu specific preparation */
 286
 287         pm_cpu_prep();
 288
 289         /* flush cache back to ram */
 290
 291         flush_cache_all();
 292
 293         s3c_pm_check_store();
 294
 295         /* send the cpu to sleep... */
 296
 297         s3c_pm_arch_stop_clocks();
 298
 299         /* this will also act as our return point from when
 300          * we resume as it saves its own register state and restores it
 301          * during the resume.  */
 302
 303         cpu_suspend(0, pm_cpu_sleep);
 304
 305         /* restore the system state */
 306
 307         s3c_pm_restore_core();
 308         s3c_pm_restore_uarts();
 309         s3c_pm_restore_gpios();
 310         s3c_pm_restored_gpios();
 311
 312         s3c_pm_debug_init();
 313
 314         /* check what irq (if any) restored the system */
 315
 316         s3c_pm_arch_show_resume_irqs();
 317
 318         S3C_PMDBG("%s: post sleep, preparing to return\n", __func__);
 319
 320         /* LEDs should now be 1110 */
 321         s3c_pm_debug_smdkled(1 << 1, 0);
 322
 323         s3c_pm_check_restore();
 324
 325         /* ok, let's return from sleep */
 326
 327         S3C_PMDBG("S3C PM Resume (post-restore)\n");
 328         return 0;
 329 }
 330
 331 static int s3c_pm_prepare(void)
 332 {
 333         /* prepare check area if configured */
 334
 335         s3c_pm_check_prepare();
 336         return 0;
 337 }
 338
 339 static void s3c_pm_finish(void)
 340 {
 341         s3c_pm_check_cleanup();
 342 }
 343
 344 static const struct platform_suspend_ops s3c_pm_ops = {
 345         .enter          = s3c_pm_enter,
 346         .prepare        = s3c_pm_prepare,
 347         .finish         = s3c_pm_finish,
 348         .valid          = suspend_valid_only_mem,
 349 };
 350
 351 /* s3c_pm_init
 352  *
 353  * Attach the power management functions. This should be called
 354  * from the board specific initialisation if the board supports
 355  * it.
 356 */
 357
 358 int __init s3c_pm_init(void)
 359 {
 360         printk("S3C Power Management, Copyright 2004 Simtec Electronics\n");
 361
 362         suspend_set_ops(&s3c_pm_ops);
 363         return 0;
 364 }