arch/arm/plat-s3c/pm.c

   1 /* linux/arch/arm/plat-s3c/pm.c
   2  *
   3  * Copyright 2008 Openmoko, Inc.
   4  * Copyright 2004,2006,2008 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 <mach/hardware.h>
  24
  25 #include <plat/regs-serial.h>
  26 #include <mach/regs-clock.h>
  27 #include <mach/regs-gpio.h>
  28 #include <mach/regs-mem.h>
  29 #include <mach/regs-irq.h>
  30 #include <asm/irq.h>
  31
  32 #include <plat/pm.h>
  33 #include <plat/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_S3C2410_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_S3C2410_PM_DEBUG */
  70
  71 /* Save the UART configurations if we are configured for debug. */
  72
  73 #ifdef CONFIG_S3C2410_PM_DEBUG
  74
  75 struct pm_uart_save uart_save[CONFIG_SERIAL_SAMSUNG_UARTS];
  76
  77 static void s3c_pm_save_uart(unsigned int uart, struct pm_uart_save *save)
  78 {
  79         void __iomem *regs = S3C_VA_UARTx(uart);
  80
  81         save->ulcon = __raw_readl(regs + S3C2410_ULCON);
  82         save->ucon = __raw_readl(regs + S3C2410_UCON);
  83         save->ufcon = __raw_readl(regs + S3C2410_UFCON);
  84         save->umcon = __raw_readl(regs + S3C2410_UMCON);
  85         save->ubrdiv = __raw_readl(regs + S3C2410_UBRDIV);
  86 }
  87
  88 static void s3c_pm_save_uarts(void)
  89 {
  90         struct pm_uart_save *save = uart_save;
  91         unsigned int uart;
  92
  93         for (uart = 0; uart < CONFIG_SERIAL_SAMSUNG_UARTS; uart++, save++)
  94                 s3c_pm_save_uart(uart, save);
  95 }
  96
  97 static void s3c_pm_restore_uart(unsigned int uart, struct pm_uart_save *save)
  98 {
  99         void __iomem *regs = S3C_VA_UARTx(uart);
 100
 101         __raw_writel(save->ulcon, regs + S3C2410_ULCON);
 102         __raw_writel(save->ucon,  regs + S3C2410_UCON);
 103         __raw_writel(save->ufcon, regs + S3C2410_UFCON);
 104         __raw_writel(save->umcon, regs + S3C2410_UMCON);
 105         __raw_writel(save->ubrdiv, regs + S3C2410_UBRDIV);
 106 }
 107
 108 static void s3c_pm_restore_uarts(void)
 109 {
 110         struct pm_uart_save *save = uart_save;
 111         unsigned int uart;
 112
 113         for (uart = 0; uart < CONFIG_SERIAL_SAMSUNG_UARTS; uart++, save++)
 114                 s3c_pm_restore_uart(uart, save);
 115 }
 116 #else
 117 static void s3c_pm_save_uarts(void) { }
 118 static void s3c_pm_restore_uarts(void) { }
 119 #endif
 120
 121 /* The IRQ ext-int code goes here, it is too small to currently bother
 122  * with its own file. */
 123
 124 unsigned long s3c_irqwake_intmask       = 0xffffffffL;
 125 unsigned long s3c_irqwake_eintmask      = 0xffffffffL;
 126
 127 int s3c_irqext_wake(unsigned int irqno, unsigned int state)
 128 {
 129         unsigned long bit = 1L << IRQ_EINT_BIT(irqno);
 130
 131         if (!(s3c_irqwake_eintallow & bit))
 132                 return -ENOENT;
 133
 134         printk(KERN_INFO "wake %s for irq %d\n",
 135                state ? "enabled" : "disabled", irqno);
 136
 137         if (!state)
 138                 s3c_irqwake_eintmask |= bit;
 139         else
 140                 s3c_irqwake_eintmask &= ~bit;
 141
 142         return 0;
 143 }
 144
 145 /* helper functions to save and restore register state */
 146
 147 /**
 148  * s3c_pm_do_save() - save a set of registers for restoration on resume.
 149  * @ptr: Pointer to an array of registers.
 150  * @count: Size of the ptr array.
 151  *
 152  * Run through the list of registers given, saving their contents in the
 153  * array for later restoration when we wakeup.
 154  */
 155 void s3c_pm_do_save(struct sleep_save *ptr, int count)
 156 {
 157         for (; count > 0; count--, ptr++) {
 158                 ptr->val = __raw_readl(ptr->reg);
 159                 S3C_PMDBG("saved %p value %08lx\n", ptr->reg, ptr->val);
 160         }
 161 }
 162
 163 /**
 164  * s3c_pm_do_restore() - restore register values from the save list.
 165  * @ptr: Pointer to an array of registers.
 166  * @count: Size of the ptr array.
 167  *
 168  * Restore the register values saved from s3c_pm_do_save().
 169  *
 170  * Note, we do not use S3C_PMDBG() in here, as the system may not have
 171  * restore the UARTs state yet
 172 */
 173
 174 void s3c_pm_do_restore(struct sleep_save *ptr, int count)
 175 {
 176         for (; count > 0; count--, ptr++) {
 177                 printk(KERN_DEBUG "restore %p (restore %08lx, was %08x)\n",
 178                        ptr->reg, ptr->val, __raw_readl(ptr->reg));
 179
 180                 __raw_writel(ptr->val, ptr->reg);
 181         }
 182 }
 183
 184 /**
 185  * s3c_pm_do_restore_core() - early restore register values from save list.
 186  *
 187  * This is similar to s3c_pm_do_restore() except we try and minimise the
 188  * side effects of the function in case registers that hardware might need
 189  * to work has been restored.
 190  *
 191  * WARNING: Do not put any debug in here that may effect memory or use
 192  * peripherals, as things may be changing!
 193 */
 194
 195 void s3c_pm_do_restore_core(struct sleep_save *ptr, int count)
 196 {
 197         for (; count > 0; count--, ptr++)
 198                 __raw_writel(ptr->val, ptr->reg);
 199 }
 200
 201 /* s3c2410_pm_show_resume_irqs
 202  *
 203  * print any IRQs asserted at resume time (ie, we woke from)
 204 */
 205 static void s3c_pm_show_resume_irqs(int start, unsigned long which,
 206                                     unsigned long mask)
 207 {
 208         int i;
 209
 210         which &= ~mask;
 211
 212         for (i = 0; i <= 31; i++) {
 213                 if (which & (1L<<i)) {
 214                         S3C_PMDBG("IRQ %d asserted at resume\n", start+i);
 215                 }
 216         }
 217 }
 218
 219
 220 void (*pm_cpu_prep)(void);
 221 void (*pm_cpu_sleep)(void);
 222
 223 #define any_allowed(mask, allow) (((mask) & (allow)) != (allow))
 224
 225 /* s3c_pm_enter
 226  *
 227  * central control for sleep/resume process
 228 */
 229
 230 static int s3c_pm_enter(suspend_state_t state)
 231 {
 232         static unsigned long regs_save[16];
 233
 234         /* ensure the debug is initialised (if enabled) */
 235
 236         s3c_pm_debug_init();
 237
 238         S3C_PMDBG("%s(%d)\n", __func__, state);
 239
 240         if (pm_cpu_prep == NULL || pm_cpu_sleep == NULL) {
 241                 printk(KERN_ERR "%s: error: no cpu sleep function\n", __func__);
 242                 return -EINVAL;
 243         }
 244
 245         /* check if we have anything to wake-up with... bad things seem
 246          * to happen if you suspend with no wakeup (system will often
 247          * require a full power-cycle)
 248         */
 249
 250         if (!any_allowed(s3c_irqwake_intmask, s3c_irqwake_intallow) &&
 251             !any_allowed(s3c_irqwake_eintmask, s3c_irqwake_eintallow)) {
 252                 printk(KERN_ERR "%s: No wake-up sources!\n", __func__);
 253                 printk(KERN_ERR "%s: Aborting sleep\n", __func__);
 254                 return -EINVAL;
 255         }
 256
 257         /* store the physical address of the register recovery block */
 258
 259         s3c_sleep_save_phys = virt_to_phys(regs_save);
 260
 261         S3C_PMDBG("s3c_sleep_save_phys=0x%08lx\n", s3c_sleep_save_phys);
 262
 263         /* save all necessary core registers not covered by the drivers */
 264
 265         s3c_pm_save_gpios();
 266         s3c_pm_save_uarts();
 267         s3c_pm_save_core();
 268
 269         /* set the irq configuration for wake */
 270
 271         s3c_pm_configure_extint();
 272
 273         S3C_PMDBG("sleep: irq wakeup masks: %08lx,%08lx\n",
 274             s3c_irqwake_intmask, s3c_irqwake_eintmask);
 275
 276         s3c_pm_arch_prepare_irqs();
 277
 278         /* call cpu specific preparation */
 279
 280         pm_cpu_prep();
 281
 282         /* flush cache back to ram */
 283
 284         flush_cache_all();
 285
 286         s3c_pm_check_store();
 287
 288         /* send the cpu to sleep... */
 289
 290         s3c_pm_arch_stop_clocks();
 291
 292         /* s3c_cpu_save will also act as our return point from when
 293          * we resume as it saves its own register state and restores it
 294          * during the resume.  */
 295
 296         s3c_cpu_save(regs_save);
 297
 298         /* restore the cpu state using the kernel's cpu init code. */
 299
 300         cpu_init();
 301
 302         /* restore the system state */
 303
 304         s3c_pm_restore_core();
 305         s3c_pm_restore_uarts();
 306         s3c_pm_restore_gpios();
 307
 308         s3c_pm_debug_init();
 309
 310         /* check what irq (if any) restored the system */
 311
 312         s3c_pm_arch_show_resume_irqs();
 313
 314         S3C_PMDBG("%s: post sleep, preparing to return\n", __func__);
 315
 316         s3c_pm_check_restore();
 317
 318         /* ok, let's return from sleep */
 319
 320         S3C_PMDBG("S3C PM Resume (post-restore)\n");
 321         return 0;
 322 }
 323
 324 /* callback from assembly code */
 325 void s3c_pm_cb_flushcache(void)
 326 {
 327         flush_cache_all();
 328 }
 329
 330 static int s3c_pm_prepare(void)
 331 {
 332         /* prepare check area if configured */
 333
 334         s3c_pm_check_prepare();
 335         return 0;
 336 }
 337
 338 static void s3c_pm_finish(void)
 339 {
 340         s3c_pm_check_cleanup();
 341 }
 342
 343 static struct platform_suspend_ops s3c_pm_ops = {
 344         .enter          = s3c_pm_enter,
 345         .prepare        = s3c_pm_prepare,
 346         .finish         = s3c_pm_finish,
 347         .valid          = suspend_valid_only_mem,
 348 };
 349
 350 /* s3c_pm_init
 351  *
 352  * Attach the power management functions. This should be called
 353  * from the board specific initialisation if the board supports
 354  * it.
 355 */
 356
 357 int __init s3c_pm_init(void)
 358 {
 359         printk("S3C Power Management, Copyright 2004 Simtec Electronics\n");
 360
 361         suspend_set_ops(&s3c_pm_ops);
 362         return 0;
 363 }