1/* 2 * Copyright (C) 2014 Google, Inc 3 * Copyright (C) 2015 Bin Meng <bmeng.cn@gmail.com> 4 * 5 * SPDX-License-Identifier: GPL-2.0+ 6 */ 7 8#ifndef _ASM_MRCCACHE_H 9#define _ASM_MRCCACHE_H 10 11#define MRC_DATA_ALIGN 0x1000 12#define MRC_DATA_SIGNATURE (('M' << 0) | ('R' << 8) | \ 13 ('C' << 16) | ('D'<<24)) 14 15#define MRC_DATA_HEADER_SIZE 32 16 17struct __packed mrc_data_container { 18 u32 signature; /* "MRCD" */ 19 u32 data_size; /* Size of the 'data' field */ 20 u32 checksum; /* IP style checksum */ 21 u32 reserved; /* For header alignment */ 22 u8 data[0]; /* Variable size, platform/run time dependent */ 23}; 24 25struct mrc_region { 26 u32 base; 27 u32 offset; 28 u32 length; 29}; 30 31struct udevice; 32 33/** 34 * mrccache_find_current() - find the latest MRC cache record 35 * 36 * This searches the MRC cache region looking for the latest record to use 37 * for setting up SDRAM 38 * 39 * @entry: Position and size of MRC cache in SPI flash 40 * @return pointer to latest record, or NULL if none 41 */ 42struct mrc_data_container *mrccache_find_current(struct mrc_region *entry); 43 44/** 45 * mrccache_update() - update the MRC cache with a new record 46 * 47 * This writes a new record to the end of the MRC cache region. If the new 48 * record is the same as the latest record then the write is skipped 49 * 50 * @sf: SPI flash to write to 51 * @entry: Position and size of MRC cache in SPI flash 52 * @cur: Record to write 53 * @return 0 if updated, -EEXIST if the record is the same as the latest 54 * record, -EINVAL if the record is not valid, other error if SPI write failed 55 */ 56int mrccache_update(struct udevice *sf, struct mrc_region *entry, 57 struct mrc_data_container *cur); 58 59/** 60 * mrccache_reserve() - reserve MRC data on the stack 61 * 62 * This copies MRC data pointed by gd->arch.mrc_output to a new place on the 63 * stack with length gd->arch.mrc_output_len, and updates gd->arch.mrc_output 64 * to point to the new place once the migration is done. 65 * 66 * This routine should be called by reserve_arch() before U-Boot is relocated 67 * when MRC cache is enabled. 68 * 69 * @return 0 always 70 */ 71int mrccache_reserve(void); 72 73/** 74 * mrccache_get_region() - get MRC region on the SPI flash 75 * 76 * This gets MRC region whose offset and size are described in the device tree 77 * as a subnode to the SPI flash. If a non-NULL device pointer is supplied, 78 * this also probes the SPI flash device and returns its device pointer for 79 * the caller to use later. 80 * 81 * Be careful when calling this routine with a non-NULL device pointer: 82 * - driver model initialization must be complete 83 * - calling in the pre-relocation phase may bring some side effects during 84 * the SPI flash device probe (eg: for SPI controllers on a PCI bus, it 85 * triggers PCI bus enumeration during which insufficient memory issue 86 * might be exposed and it causes subsequent SPI flash probe fails). 87 * 88 * @devp: Returns pointer to the SPI flash device 89 * @entry: Position and size of MRC cache in SPI flash 90 * @return 0 if success, -ENOENT if SPI flash node does not exist in the 91 * device tree, -EPERM if MRC region subnode does not exist in the device 92 * tree, -EINVAL if MRC region properties format is incorrect, other error 93 * if SPI flash probe failed. 94 */ 95int mrccache_get_region(struct udevice **devp, struct mrc_region *entry); 96 97/** 98 * mrccache_save() - save MRC data to the SPI flash 99 * 100 * This saves MRC data stored previously by gd->arch.mrc_output to a proper 101 * place within the MRC region on the SPI flash. 102 * 103 * @return 0 if saved to SPI flash successfully, other error if failed 104 */ 105int mrccache_save(void); 106 107#endif /* _ASM_MRCCACHE_H */ 108