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