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
  26 #include <plat/regs-serial.h>
  27
  28 #ifdef CONFIG_SAMSUNG_ATAGS
  29 #include <mach/hardware.h>
  30 #include <mach/map.h>
  31 #include <mach/regs-clock.h>
  32 #include <mach/regs-irq.h>
  33 #include <mach/irqs.h>
  34 #endif
  35
  36 #include <asm/irq.h>
  37
  38 #include <plat/pm.h>
  39 #include <mach/pm-core.h>
  40
  41 /* for external use */
  42
  43 unsigned long s3c_pm_flags;
  44
  45 /* Debug code:
  46  *
  47  * This code supports debug output to the low level UARTs for use on
  48  * resume before the console layer is available.
  49 */
  50
  51 #ifdef CONFIG_SAMSUNG_PM_DEBUG
  52 extern void printascii(const char *);
  53
  54 void s3c_pm_dbg(const char *fmt, ...)
  55 {
  56         va_list va;
  57         char buff[256];
  58
  59         va_start(va, fmt);
  60         vsnprintf(buff, sizeof(buff), fmt, va);
  61         va_end(va);
  62
  63         printascii(buff);
  64 }
  65
  66 static inline void s3c_pm_debug_init(void)
  67 {
  68         /* restart uart clocks so we can use them to output */
  69         s3c_pm_debug_init_uart();
  70 }
  71
  72 #else
  73 #define s3c_pm_debug_init() do { } while(0)
  74
  75 #endif /* CONFIG_SAMSUNG_PM_DEBUG */
  76
  77 /* Save the UART configurations if we are configured for debug. */
  78
  79 unsigned char pm_uart_udivslot;
  80
  81 #ifdef CONFIG_SAMSUNG_PM_DEBUG
  82
  83 static struct pm_uart_save uart_save[CONFIG_SERIAL_SAMSUNG_UARTS];
  84
  85 static void s3c_pm_save_uart(unsigned int uart, struct pm_uart_save *save)
  86 {
  87         void __iomem *regs = S3C_VA_UARTx(uart);
  88
  89         save->ulcon = __raw_readl(regs + S3C2410_ULCON);
  90         save->ucon = __raw_readl(regs + S3C2410_UCON);
  91         save->ufcon = __raw_readl(regs + S3C2410_UFCON);
  92         save->umcon = __raw_readl(regs + S3C2410_UMCON);
  93         save->ubrdiv = __raw_readl(regs + S3C2410_UBRDIV);
  94
  95         if (pm_uart_udivslot)
  96                 save->udivslot = __raw_readl(regs + S3C2443_DIVSLOT);
  97
  98         S3C_PMDBG("UART[%d]: ULCON=%04x, UCON=%04x, UFCON=%04x, UBRDIV=%04x\n",
  99                   uart, save->ulcon, save->ucon, save->ufcon, save->ubrdiv);
 100 }
 101
 102 static void s3c_pm_save_uarts(void)
 103 {
 104         struct pm_uart_save *save = uart_save;
 105         unsigned int uart;
 106
 107         for (uart = 0; uart < CONFIG_SERIAL_SAMSUNG_UARTS; uart++, save++)
 108                 s3c_pm_save_uart(uart, save);
 109 }
 110
 111 static void s3c_pm_restore_uart(unsigned int uart, struct pm_uart_save *save)
 112 {
 113         void __iomem *regs = S3C_VA_UARTx(uart);
 114
 115         s3c_pm_arch_update_uart(regs, save);
 116
 117         __raw_writel(save->ulcon, regs + S3C2410_ULCON);
 118         __raw_writel(save->ucon,  regs + S3C2410_UCON);
 119         __raw_writel(save->ufcon, regs + S3C2410_UFCON);
 120         __raw_writel(save->umcon, regs + S3C2410_UMCON);
 121         __raw_writel(save->ubrdiv, regs + S3C2410_UBRDIV);
 122
 123         if (pm_uart_udivslot)
 124                 __raw_writel(save->udivslot, regs + S3C2443_DIVSLOT);
 125 }
 126
 127 static void s3c_pm_restore_uarts(void)
 128 {
 129         struct pm_uart_save *save = uart_save;
 130         unsigned int uart;
 131
 132         for (uart = 0; uart < CONFIG_SERIAL_SAMSUNG_UARTS; uart++, save++)
 133                 s3c_pm_restore_uart(uart, save);
 134 }
 135 #else
 136 static void s3c_pm_save_uarts(void) { }
 137 static void s3c_pm_restore_uarts(void) { }
 138 #endif
 139
 140 /* The IRQ ext-int code goes here, it is too small to currently bother
 141  * with its own file. */
 142
 143 unsigned long s3c_irqwake_intmask       = 0xffffffffL;
 144 unsigned long s3c_irqwake_eintmask      = 0xffffffffL;
 145
 146 int s3c_irqext_wake(struct irq_data *data, unsigned int state)
 147 {
 148         unsigned long bit = 1L << IRQ_EINT_BIT(data->irq);
 149
 150         if (!(s3c_irqwake_eintallow & bit))
 151                 return -ENOENT;
 152
 153         printk(KERN_INFO "wake %s for irq %d\n",
 154                state ? "enabled" : "disabled", data->irq);
 155
 156         if (!state)
 157                 s3c_irqwake_eintmask |= bit;
 158         else
 159                 s3c_irqwake_eintmask &= ~bit;
 160
 161         return 0;
 162 }
 163
 164 /* helper functions to save and restore register state */
 165
 166 /**
 167  * s3c_pm_do_save() - save a set of registers for restoration on resume.
 168  * @ptr: Pointer to an array of registers.
 169  * @count: Size of the ptr array.
 170  *
 171  * Run through the list of registers given, saving their contents in the
 172  * array for later restoration when we wakeup.
 173  */
 174 void s3c_pm_do_save(struct sleep_save *ptr, int count)
 175 {
 176         for (; count > 0; count--, ptr++) {
 177                 ptr->val = __raw_readl(ptr->reg);
 178                 S3C_PMDBG("saved %p value %08lx\n", ptr->reg, ptr->val);
 179         }
 180 }
 181
 182 /**
 183  * s3c_pm_do_restore() - restore register values from the save list.
 184  * @ptr: Pointer to an array of registers.
 185  * @count: Size of the ptr array.
 186  *
 187  * Restore the register values saved from s3c_pm_do_save().
 188  *
 189  * Note, we do not use S3C_PMDBG() in here, as the system may not have
 190  * restore the UARTs state yet
 191 */
 192
 193 void s3c_pm_do_restore(struct sleep_save *ptr, int count)
 194 {
 195         for (; count > 0; count--, ptr++) {
 196                 printk(KERN_DEBUG "restore %p (restore %08lx, was %08x)\n",
 197                        ptr->reg, ptr->val, __raw_readl(ptr->reg));
 198
 199                 __raw_writel(ptr->val, ptr->reg);
 200         }
 201 }
 202
 203 /**
 204  * s3c_pm_do_restore_core() - early restore register values from save list.
 205  *
 206  * This is similar to s3c_pm_do_restore() except we try and minimise the
 207  * side effects of the function in case registers that hardware might need
 208  * to work has been restored.
 209  *
 210  * WARNING: Do not put any debug in here that may effect memory or use
 211  * peripherals, as things may be changing!
 212 */
 213
 214 void s3c_pm_do_restore_core(struct sleep_save *ptr, int count)
 215 {
 216         for (; count > 0; count--, ptr++)
 217                 __raw_writel(ptr->val, ptr->reg);
 218 }
 219
 220 /* s3c2410_pm_show_resume_irqs
 221  *
 222  * print any IRQs asserted at resume time (ie, we woke from)
 223 */
 224 static void __maybe_unused s3c_pm_show_resume_irqs(int start,
 225                                                    unsigned long which,
 226                                                    unsigned long mask)
 227 {
 228         int i;
 229
 230         which &= ~mask;
 231
 232         for (i = 0; i <= 31; i++) {
 233                 if (which & (1L<<i)) {
 234                         S3C_PMDBG("IRQ %d asserted at resume\n", start+i);
 235                 }
 236         }
 237 }
 238
 239
 240 void (*pm_cpu_prep)(void);
 241 int (*pm_cpu_sleep)(unsigned long);
 242
 243 #define any_allowed(mask, allow) (((mask) & (allow)) != (allow))
 244
 245 /* s3c_pm_enter
 246  *
 247  * central control for sleep/resume process
 248 */
 249
 250 static int s3c_pm_enter(suspend_state_t state)
 251 {
 252         int ret;
 253         /* ensure the debug is initialised (if enabled) */
 254
 255         s3c_pm_debug_init();
 256
 257         S3C_PMDBG("%s(%d)\n", __func__, state);
 258
 259         if (pm_cpu_prep == NULL || pm_cpu_sleep == NULL) {
 260                 printk(KERN_ERR "%s: error: no cpu sleep function\n", __func__);
 261                 return -EINVAL;
 262         }
 263
 264         /* check if we have anything to wake-up with... bad things seem
 265          * to happen if you suspend with no wakeup (system will often
 266          * require a full power-cycle)
 267         */
 268
 269         if (!of_have_populated_dt() &&
 270             !any_allowed(s3c_irqwake_intmask, s3c_irqwake_intallow) &&
 271             !any_allowed(s3c_irqwake_eintmask, s3c_irqwake_eintallow)) {
 272                 printk(KERN_ERR "%s: No wake-up sources!\n", __func__);
 273                 printk(KERN_ERR "%s: Aborting sleep\n", __func__);
 274                 return -EINVAL;
 275         }
 276
 277         /* save all necessary core registers not covered by the drivers */
 278
 279         if (!of_have_populated_dt()) {
 280                 samsung_pm_save_gpios();
 281                 samsung_pm_saved_gpios();
 282         }
 283
 284         s3c_pm_save_uarts();
 285         s3c_pm_save_core();
 286
 287         /* set the irq configuration for wake */
 288
 289         s3c_pm_configure_extint();
 290
 291         S3C_PMDBG("sleep: irq wakeup masks: %08lx,%08lx\n",
 292             s3c_irqwake_intmask, s3c_irqwake_eintmask);
 293
 294         s3c_pm_arch_prepare_irqs();
 295
 296         /* call cpu specific preparation */
 297
 298         pm_cpu_prep();
 299
 300         /* flush cache back to ram */
 301
 302         flush_cache_all();
 303
 304         s3c_pm_check_store();
 305
 306         /* send the cpu to sleep... */
 307
 308         s3c_pm_arch_stop_clocks();
 309
 310         /* this will also act as our return point from when
 311          * we resume as it saves its own register state and restores it
 312          * during the resume.  */
 313
 314         ret = cpu_suspend(0, pm_cpu_sleep);
 315         if (ret)
 316                 return ret;
 317
 318         /* restore the system state */
 319
 320         s3c_pm_restore_core();
 321         s3c_pm_restore_uarts();
 322
 323         if (!of_have_populated_dt()) {
 324                 samsung_pm_restore_gpios();
 325                 s3c_pm_restored_gpios();
 326         }
 327
 328         s3c_pm_debug_init();
 329
 330         /* check what irq (if any) restored the system */
 331
 332         s3c_pm_arch_show_resume_irqs();
 333
 334         S3C_PMDBG("%s: post sleep, preparing to return\n", __func__);
 335
 336         /* LEDs should now be 1110 */
 337         s3c_pm_debug_smdkled(1 << 1, 0);
 338
 339         s3c_pm_check_restore();
 340
 341         /* ok, let's return from sleep */
 342
 343         S3C_PMDBG("S3C PM Resume (post-restore)\n");
 344         return 0;
 345 }
 346
 347 static int s3c_pm_prepare(void)
 348 {
 349         /* prepare check area if configured */
 350
 351         s3c_pm_check_prepare();
 352         return 0;
 353 }
 354
 355 static void s3c_pm_finish(void)
 356 {
 357         s3c_pm_check_cleanup();
 358 }
 359
 360 static const struct platform_suspend_ops s3c_pm_ops = {
 361         .enter          = s3c_pm_enter,
 362         .prepare        = s3c_pm_prepare,
 363         .finish         = s3c_pm_finish,
 364         .valid          = suspend_valid_only_mem,
 365 };
 366
 367 /* s3c_pm_init
 368  *
 369  * Attach the power management functions. This should be called
 370  * from the board specific initialisation if the board supports
 371  * it.
 372 */
 373
 374 int __init s3c_pm_init(void)
 375 {
 376         printk("S3C Power Management, Copyright 2004 Simtec Electronics\n");
 377
 378         suspend_set_ops(&s3c_pm_ops);
 379         return 0;
 380 }