arch/arm/plat-samsung/pm-common.c

   1 /*
   2  * Copyright (C) 2013 Samsung Electronics Co., Ltd.
   3  *      Tomasz Figa <t.figa@samsung.com>
   4  * Copyright (C) 2008 Openmoko, Inc.
   5  * Copyright (C) 2004-2008 Simtec Electronics
   6  *      Ben Dooks <ben@simtec.co.uk>
   7  *      http://armlinux.simtec.co.uk/
   8  *
   9  * Samsung common power management helper functions.
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License version 2 as
  13  * published by the Free Software Foundation.
  14 */
  15
  16 #include <linux/io.h>
  17 #include <linux/kernel.h>
  18
  19 #include <plat/pm-common.h>
  20
  21 /* helper functions to save and restore register state */
  22
  23 /**
  24  * s3c_pm_do_save() - save a set of registers for restoration on resume.
  25  * @ptr: Pointer to an array of registers.
  26  * @count: Size of the ptr array.
  27  *
  28  * Run through the list of registers given, saving their contents in the
  29  * array for later restoration when we wakeup.
  30  */
  31 void s3c_pm_do_save(struct sleep_save *ptr, int count)
  32 {
  33         for (; count > 0; count--, ptr++) {
  34                 ptr->val = readl_relaxed(ptr->reg);
  35                 S3C_PMDBG("saved %p value %08lx\n", ptr->reg, ptr->val);
  36         }
  37 }
  38
  39 /**
  40  * s3c_pm_do_restore() - restore register values from the save list.
  41  * @ptr: Pointer to an array of registers.
  42  * @count: Size of the ptr array.
  43  *
  44  * Restore the register values saved from s3c_pm_do_save().
  45  *
  46  * Note, we do not use S3C_PMDBG() in here, as the system may not have
  47  * restore the UARTs state yet
  48 */
  49
  50 void s3c_pm_do_restore(const struct sleep_save *ptr, int count)
  51 {
  52         for (; count > 0; count--, ptr++) {
  53                 pr_debug("restore %p (restore %08lx, was %08x)\n",
  54                                 ptr->reg, ptr->val, readl_relaxed(ptr->reg));
  55
  56                 writel_relaxed(ptr->val, ptr->reg);
  57         }
  58 }
  59
  60 /**
  61  * s3c_pm_do_restore_core() - early restore register values from save list.
  62  *
  63  * This is similar to s3c_pm_do_restore() except we try and minimise the
  64  * side effects of the function in case registers that hardware might need
  65  * to work has been restored.
  66  *
  67  * WARNING: Do not put any debug in here that may effect memory or use
  68  * peripherals, as things may be changing!
  69 */
  70
  71 void s3c_pm_do_restore_core(const struct sleep_save *ptr, int count)
  72 {
  73         for (; count > 0; count--, ptr++)
  74                 writel_relaxed(ptr->val, ptr->reg);
  75 }