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 17 struct __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 25 struct fmap_entry; 26 struct udevice; 27 28 /** 29 * mrccache_find_current() - find the latest MRC cache record 30 * 31 * This searches the MRC cache region looking for the latest record to use 32 * for setting up SDRAM 33 * 34 * @entry: Position and size of MRC cache in SPI flash 35 * @return pointer to latest record, or NULL if none 36 */ 37 struct mrc_data_container *mrccache_find_current(struct fmap_entry *entry); 38 39 /** 40 * mrccache_update() - update the MRC cache with a new record 41 * 42 * This writes a new record to the end of the MRC cache region. If the new 43 * record is the same as the latest record then the write is skipped 44 * 45 * @sf: SPI flash to write to 46 * @entry: Position and size of MRC cache in SPI flash 47 * @cur: Record to write 48 * @return 0 if updated, -EEXIST if the record is the same as the latest 49 * record, -EINVAL if the record is not valid, other error if SPI write failed 50 */ 51 int mrccache_update(struct udevice *sf, struct fmap_entry *entry, 52 struct mrc_data_container *cur); 53 54 /** 55 * mrccache_reserve() - reserve MRC data on the stack 56 * 57 * This copies MRC data pointed by gd->arch.mrc_output to a new place on the 58 * stack with length gd->arch.mrc_output_len, and updates gd->arch.mrc_output 59 * to point to the new place once the migration is done. 60 * 61 * This routine should be called by reserve_arch() before U-Boot is relocated 62 * when MRC cache is enabled. 63 * 64 * @return 0 always 65 */ 66 int mrccache_reserve(void); 67 68 /** 69 * mrccache_get_region() - get MRC region on the SPI flash 70 * 71 * This gets MRC region whose offset and size are described in the device tree 72 * as a subnode to the SPI flash. If a non-NULL device pointer is supplied, 73 * this also probes the SPI flash device and returns its device pointer for 74 * the caller to use later. 75 * 76 * Be careful when calling this routine with a non-NULL device pointer: 77 * - driver model initialization must be complete 78 * - calling in the pre-relocation phase may bring some side effects during 79 * the SPI flash device probe (eg: for SPI controllers on a PCI bus, it 80 * triggers PCI bus enumeration during which insufficient memory issue 81 * might be exposed and it causes subsequent SPI flash probe fails). 82 * 83 * @devp: Returns pointer to the SPI flash device 84 * @entry: Position and size of MRC cache in SPI flash 85 * @return 0 if success, -ENOENT if SPI flash node does not exist in the 86 * device tree, -EPERM if MRC region subnode does not exist in the device 87 * tree, -EINVAL if MRC region properties format is incorrect, other error 88 * if SPI flash probe failed. 89 */ 90 int mrccache_get_region(struct udevice **devp, struct fmap_entry *entry); 91 92 /** 93 * mrccache_save() - save MRC data to the SPI flash 94 * 95 * This saves MRC data stored previously by gd->arch.mrc_output to a proper 96 * place within the MRC region on the SPI flash. 97 * 98 * @return 0 if saved to SPI flash successfully, other error if failed 99 */ 100 int mrccache_save(void); 101 102 #endif /* _ASM_MRCCACHE_H */ 103