LXR linux/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 */
  27void 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
  46void 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
  67void 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}
  72