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 <mach/hardware.h>
  24 #include <mach/map.h>
  25
  26 #include <plat/regs-serial.h>
  27 #include <mach/regs-clock.h>
  28 #include <mach/regs-irq.h>
  29 #include <asm/irq.h>
  30
  31 #include <plat/pm.h>
  32 #include <mach/pm-core.h>
  33
  34 /* for external use */
  35
  36 unsigned long s3c_pm_flags;
  37
  38 /* Debug code:
  39  *
  40  * This code supports debug output to the low level UARTs for use on
  41  * resume before the console layer is available.
  42 */
  43
  44 #ifdef CONFIG_SAMSUNG_PM_DEBUG
  45 extern void printascii(const char *);
  46
  47 void s3c_pm_dbg(const char *fmt, ...)
  48 {
  49         va_list va;
  50         char buff[256];
  51
  52         va_start(va, fmt);
  53         vsprintf(buff, fmt, va);
  54         va_end(va);
  55
  56         printascii(buff);
  57 }
  58
  59 static inline void s3c_pm_debug_init(void)
  60 {
  61         /* restart uart clocks so we can use them to output */
  62         s3c_pm_debug_init_uart();
  63 }
  64
  65 #else
  66 #define s3c_pm_debug_init() do { } while(0)
  67
  68 #endif /* CONFIG_SAMSUNG_PM_DEBUG */
  69
  70 /* Save the UART configurations if we are configured for debug. */
  71
  72 unsigned char pm_uart_udivslot;
  73
  74 #ifdef CONFIG_SAMSUNG_PM_DEBUG
  75
  76 struct pm_uart_save uart_save[CONFIG_SERIAL_SAMSUNG_UARTS];
  77
  78 static void s3c_pm_save_uart(unsigned int uart, struct pm_uart_save *save)
  79 {
  80         void __iomem *regs = S3C_VA_UARTx(uart);
  81
  82         save->ulcon = __raw_readl(regs + S3C2410_ULCON);
  83         save->ucon = __raw_readl(regs + S3C2410_UCON);
  84         save->ufcon = __raw_readl(regs + S3C2410_UFCON);
  85         save->umcon = __raw_readl(regs + S3C2410_UMCON);
  86         save->ubrdiv = __raw_readl(regs + S3C2410_UBRDIV);
  87
  88         if (pm_uart_udivslot)
  89                 save->udivslot = __raw_readl(regs + S3C2443_DIVSLOT);
  90
  91         S3C_PMDBG("UART[%d]: ULCON=%04x, UCON=%04x, UFCON=%04x, UBRDIV=%04x\n",
  92                   uart, save->ulcon, save->ucon, save->ufcon, save->ubrdiv);
  93 }
  94
  95 static void s3c_pm_save_uarts(void)
  96 {
  97         struct pm_uart_save *save = uart_save;
  98         unsigned int uart;
  99
 100         for (uart = 0; uart < CONFIG_SERIAL_SAMSUNG_UARTS; uart++, save++)
 101                 s3c_pm_save_uart(uart, save);
 102 }
 103
 104 static void s3c_pm_restore_uart(unsigned int uart, struct pm_uart_save *save)
 105 {
 106         void __iomem *regs = S3C_VA_UARTx(uart);
 107
 108         s3c_pm_arch_update_uart(regs, save);
 109
 110         __raw_writel(save->ulcon, regs + S3C2410_ULCON);
 111         __raw_writel(save->ucon,  regs + S3C2410_UCON);
 112         __raw_writel(save->ufcon, regs + S3C2410_UFCON);
 113         __raw_writel(save->umcon, regs + S3C2410_UMCON);
 114         __raw_writel(save->ubrdiv, regs + S3C2410_UBRDIV);
 115
 116         if (pm_uart_udivslot)
 117                 __raw_writel(save->udivslot, regs + S3C2443_DIVSLOT);
 118 }
 119
 120 static void s3c_pm_restore_uarts(void)
 121 {
 122         struct pm_uart_save *save = uart_save;
 123         unsigned int uart;
 124
 125         for (uart = 0; uart < CONFIG_SERIAL_SAMSUNG_UARTS; uart++, save++)
 126                 s3c_pm_restore_uart(uart, save);
 127 }
 128 #else
 129 static void s3c_pm_save_uarts(void) { }
 130 static void s3c_pm_restore_uarts(void) { }
 131 #endif
 132
 133 /* The IRQ ext-int code goes here, it is too small to currently bother
 134  * with its own file. */
 135
 136 unsigned long s3c_irqwake_intmask       = 0xffffffffL;
 137 unsigned long s3c_irqwake_eintmask      = 0xffffffffL;
 138
 139 int s3c_irqext_wake(struct irq_data *data, unsigned int state)
 140 {
 141         unsigned long bit = 1L << IRQ_EINT_BIT(data->irq);
 142
 143         if (!(s3c_irqwake_eintallow & bit))
 144                 return -ENOENT;
 145
 146         printk(KERN_INFO "wake %s for irq %d\n",
 147                state ? "enabled" : "disabled", data->irq);
 148
 149         if (!state)
 150                 s3c_irqwake_eintmask |= bit;
 151         else
 152                 s3c_irqwake_eintmask &= ~bit;
 153
 154         return 0;
 155 }
 156
 157 /* helper functions to save and restore register state */
 158
 159 /**
 160  * s3c_pm_do_save() - save a set of registers for restoration on resume.
 161  * @ptr: Pointer to an array of registers.
 162  * @count: Size of the ptr array.
 163  *
 164  * Run through the list of registers given, saving their contents in the
 165  * array for later restoration when we wakeup.
 166  */
 167 void s3c_pm_do_save(struct sleep_save *ptr, int count)
 168 {
 169         for (; count > 0; count--, ptr++) {
 170                 ptr->val = __raw_readl(ptr->reg);
 171                 S3C_PMDBG("saved %p value %08lx\n", ptr->reg, ptr->val);
 172         }
 173 }
 174
 175 /**
 176  * s3c_pm_do_restore() - restore register values from the save list.
 177  * @ptr: Pointer to an array of registers.
 178  * @count: Size of the ptr array.
 179  *
 180  * Restore the register values saved from s3c_pm_do_save().
 181  *
 182  * Note, we do not use S3C_PMDBG() in here, as the system may not have
 183  * restore the UARTs state yet
 184 */
 185
 186 void s3c_pm_do_restore(struct sleep_save *ptr, int count)
 187 {
 188         for (; count > 0; count--, ptr++) {
 189                 printk(KERN_DEBUG "restore %p (restore %08lx, was %08x)\n",
 190                        ptr->reg, ptr->val, __raw_readl(ptr->reg));
 191
 192                 __raw_writel(ptr->val, ptr->reg);
 193         }
 194 }
 195
 196 /**
 197  * s3c_pm_do_restore_core() - early restore register values from save list.
 198  *
 199  * This is similar to s3c_pm_do_restore() except we try and minimise the
 200  * side effects of the function in case registers that hardware might need
 201  * to work has been restored.
 202  *
 203  * WARNING: Do not put any debug in here that may effect memory or use
 204  * peripherals, as things may be changing!
 205 */
 206
 207 void s3c_pm_do_restore_core(struct sleep_save *ptr, int count)
 208 {
 209         for (; count > 0; count--, ptr++)
 210                 __raw_writel(ptr->val, ptr->reg);
 211 }
 212
 213 /* s3c2410_pm_show_resume_irqs
 214  *
 215  * print any IRQs asserted at resume time (ie, we woke from)
 216 */
 217 static void __maybe_unused s3c_pm_show_resume_irqs(int start,
 218                                                    unsigned long which,
 219                                                    unsigned long mask)
 220 {
 221         int i;
 222
 223         which &= ~mask;
 224
 225         for (i = 0; i <= 31; i++) {
 226                 if (which & (1L<<i)) {
 227                         S3C_PMDBG("IRQ %d asserted at resume\n", start+i);
 228                 }
 229         }
 230 }
 231
 232
 233 void (*pm_cpu_prep)(void);
 234 void (*pm_cpu_sleep)(void);
 235
 236 #define any_allowed(mask, allow) (((mask) & (allow)) != (allow))
 237
 238 /* s3c_pm_enter
 239  *
 240  * central control for sleep/resume process
 241 */
 242
 243 static int s3c_pm_enter(suspend_state_t state)
 244 {
 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 (!any_allowed(s3c_irqwake_intmask, s3c_irqwake_intallow) &&
 262             !any_allowed(s3c_irqwake_eintmask, s3c_irqwake_eintallow)) {
 263                 printk(KERN_ERR "%s: No wake-up sources!\n", __func__);
 264                 printk(KERN_ERR "%s: Aborting sleep\n", __func__);
 265                 return -EINVAL;
 266         }
 267
 268         /* save all necessary core registers not covered by the drivers */
 269
 270         s3c_pm_save_gpios();
 271         s3c_pm_save_uarts();
 272         s3c_pm_save_core();
 273
 274         /* set the irq configuration for wake */
 275
 276         s3c_pm_configure_extint();
 277
 278         S3C_PMDBG("sleep: irq wakeup masks: %08lx,%08lx\n",
 279             s3c_irqwake_intmask, s3c_irqwake_eintmask);
 280
 281         s3c_pm_arch_prepare_irqs();
 282
 283         /* call cpu specific preparation */
 284
 285         pm_cpu_prep();
 286
 287         /* flush cache back to ram */
 288
 289         flush_cache_all();
 290
 291         s3c_pm_check_store();
 292
 293         /* send the cpu to sleep... */
 294
 295         s3c_pm_arch_stop_clocks();
 296
 297         /* s3c_cpu_save will also act as our return point from when
 298          * we resume as it saves its own register state and restores it
 299          * during the resume.  */
 300
 301         s3c_cpu_save(0, PLAT_PHYS_OFFSET - PAGE_OFFSET);
 302
 303         /* restore the cpu state using the kernel's cpu init code. */
 304
 305         cpu_init();
 306
 307         /* restore the system state */
 308
 309         s3c_pm_restore_core();
 310         s3c_pm_restore_uarts();
 311         s3c_pm_restore_gpios();
 312
 313         s3c_pm_debug_init();
 314
 315         /* check what irq (if any) restored the system */
 316
 317         s3c_pm_arch_show_resume_irqs();
 318
 319         S3C_PMDBG("%s: post sleep, preparing to return\n", __func__);
 320
 321         /* LEDs should now be 1110 */
 322         s3c_pm_debug_smdkled(1 << 1, 0);
 323
 324         s3c_pm_check_restore();
 325
 326         /* ok, let's return from sleep */
 327
 328         S3C_PMDBG("S3C PM Resume (post-restore)\n");
 329         return 0;
 330 }
 331
 332 static int s3c_pm_prepare(void)
 333 {
 334         /* prepare check area if configured */
 335
 336         s3c_pm_check_prepare();
 337         return 0;
 338 }
 339
 340 static void s3c_pm_finish(void)
 341 {
 342         s3c_pm_check_cleanup();
 343 }
 344
 345 static const struct platform_suspend_ops s3c_pm_ops = {
 346         .enter          = s3c_pm_enter,
 347         .prepare        = s3c_pm_prepare,
 348         .finish         = s3c_pm_finish,
 349         .valid          = suspend_valid_only_mem,
 350 };
 351
 352 /* s3c_pm_init
 353  *
 354  * Attach the power management functions. This should be called
 355  * from the board specific initialisation if the board supports
 356  * it.
 357 */
 358
 359 int __init s3c_pm_init(void)
 360 {
 361         printk("S3C Power Management, Copyright 2004 Simtec Electronics\n");
 362
 363         suspend_set_ops(&s3c_pm_ops);
 364         return 0;
 365 }