linux/arch/arm/mach-s3c/pm-common.c

// SPDX-License-Identifier: GPL-2.0
//
// Copyright (C) 2013 Samsung Electronics Co., Ltd.
//	Tomasz Figa <t.figa@samsung.com>
// Copyright (C) 2008 Openmoko, Inc.
// Copyright (C) 2004-2008 Simtec Electronics
//	Ben Dooks <ben@simtec.co.uk>
//	http://armlinux.simtec.co.uk/
//
// Samsung common power management helper functions.

#include <linux/io.h>
#include <linux/kernel.h>

#include "pm-common.h"

/* helper functions to save and restore register state */

/**
 * s3c_pm_do_save() - save a set of registers for restoration on resume.
 * @ptr: Pointer to an array of registers.
 * @count: Size of the ptr array.
 *
 * Run through the list of registers given, saving their contents in the
 * array for later restoration when we wakeup.
 */
void s3c_pm_do_save(struct sleep_save *ptr, int count)
{
	for (; count > 0; count--, ptr++) {
		ptr->val = readl_relaxed(ptr->reg);
		S3C_PMDBG("saved %p value %08lx\n", ptr->reg, ptr->val);
	}
}

/**
 * s3c_pm_do_restore() - restore register values from the save list.
 * @ptr: Pointer to an array of registers.
 * @count: Size of the ptr array.
 *
 * Restore the register values saved from s3c_pm_do_save().
 *
 * Note, we do not use S3C_PMDBG() in here, as the system may not have
 * restore the UARTs state yet
*/

void s3c_pm_do_restore(const struct sleep_save *ptr, int count)
{
	for (; count > 0; count--, ptr++) {
		pr_debug("restore %p (restore %08lx, was %08x)\n",
				ptr->reg, ptr->val, readl_relaxed(ptr->reg));

		writel_relaxed(ptr->val, ptr->reg);
	}
}

/**
 * s3c_pm_do_restore_core() - early restore register values from save list.
 * @ptr: Pointer to an array of registers.
 * @count: Size of the ptr array.
 *
 * This is similar to s3c_pm_do_restore() except we try and minimise the
 * side effects of the function in case registers that hardware might need
 * to work has been restored.
 *
 * WARNING: Do not put any debug in here that may effect memory or use
 * peripherals, as things may be changing!
*/

void s3c_pm_do_restore_core(const struct sleep_save *ptr, int count)
{
	for (; count > 0; count--, ptr++)
		writel_relaxed(ptr->val, ptr->reg);
}