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

   1 // SPDX-License-Identifier: GPL-2.0
   2 //
   3 // Copyright (C) 2013 Samsung Electronics Co., Ltd.
   4 //      Tomasz Figa <t.figa@samsung.com>
   5 // Copyright (C) 2008 Openmoko, Inc.
   6 // Copyright (C) 2004-2008 Simtec Electronics
   7 //      Ben Dooks <ben@simtec.co.uk>
   8 //      http://armlinux.simtec.co.uk/
   9 //
  10 // Samsung common power management helper functions.
  11
  12 #include <linux/io.h>
  13 #include <linux/kernel.h>
  14
  15 #include <plat/pm-common.h>
  16
  17 /* helper functions to save and restore register state */
  18
  19 /**
  20  * s3c_pm_do_save() - save a set of registers for restoration on resume.
  21  * @ptr: Pointer to an array of registers.
  22  * @count: Size of the ptr array.
  23  *
  24  * Run through the list of registers given, saving their contents in the
  25  * array for later restoration when we wakeup.
  26  */
  27 void s3c_pm_do_save(struct sleep_save *ptr, int count)
  28 {
  29         for (; count > 0; count--, ptr++) {
  30                 ptr->val = readl_relaxed(ptr->reg);
  31                 S3C_PMDBG("saved %p value %08lx\n", ptr->reg, ptr->val);
  32         }
  33 }
  34
  35 /**
  36  * s3c_pm_do_restore() - restore register values from the save list.
  37  * @ptr: Pointer to an array of registers.
  38  * @count: Size of the ptr array.
  39  *
  40  * Restore the register values saved from s3c_pm_do_save().
  41  *
  42  * Note, we do not use S3C_PMDBG() in here, as the system may not have
  43  * restore the UARTs state yet
  44 */
  45
  46 void s3c_pm_do_restore(const struct sleep_save *ptr, int count)
  47 {
  48         for (; count > 0; count--, ptr++) {
  49                 pr_debug("restore %p (restore %08lx, was %08x)\n",
  50                                 ptr->reg, ptr->val, readl_relaxed(ptr->reg));
  51
  52                 writel_relaxed(ptr->val, ptr->reg);
  53         }
  54 }
  55
  56 /**
  57  * s3c_pm_do_restore_core() - early restore register values from save list.
  58  *
  59  * This is similar to s3c_pm_do_restore() except we try and minimise the
  60  * side effects of the function in case registers that hardware might need
  61  * to work has been restored.
  62  *
  63  * WARNING: Do not put any debug in here that may effect memory or use
  64  * peripherals, as things may be changing!
  65 */
  66
  67 void s3c_pm_do_restore_core(const struct sleep_save *ptr, int count)
  68 {
  69         for (; count > 0; count--, ptr++)
  70                 writel_relaxed(ptr->val, ptr->reg);
  71 }