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 "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 * @ptr: Pointer to an array of registers. 59 * @count: Size of the ptr array. 60 * 61 * This is similar to s3c_pm_do_restore() except we try and minimise the 62 * side effects of the function in case registers that hardware might need 63 * to work has been restored. 64 * 65 * WARNING: Do not put any debug in here that may effect memory or use 66 * peripherals, as things may be changing! 67 */ 68 69 void s3c_pm_do_restore_core(const struct sleep_save *ptr, int count) 70 { 71 for (; count > 0; count--, ptr++) 72 writel_relaxed(ptr->val, ptr->reg); 73 } 74