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Diffstat (limited to 'arch/arm/mach-s3c/pm-common.c')
-rw-r--r-- | arch/arm/mach-s3c/pm-common.c | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/arch/arm/mach-s3c/pm-common.c b/arch/arm/mach-s3c/pm-common.c new file mode 100644 index 000000000..618bd4499 --- /dev/null +++ b/arch/arm/mach-s3c/pm-common.c @@ -0,0 +1,73 @@ +// 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); +} |