1// SPDX-License-Identifier: GPL-2.0+ 2/* 3 * (C) Copyright 2019 Collabora 4 * (C) Copyright 2019 GE 5 */ 6 7#include <common.h> 8#include <bootcount.h> 9#include <dm.h> 10#include <spi_flash.h> 11 12static const u8 bootcount_magic = 0xbc; 13 14struct bootcount_spi_flash_priv { 15 struct udevice *spi_flash; 16 u32 offset; 17}; 18 19static int bootcount_spi_flash_update(struct udevice *dev, u32 offset, u32 len, const void *buf) 20{ 21 struct spi_flash *flash = dev_get_uclass_priv(dev); 22 u32 sector_size = flash->sector_size; 23 u32 sector_offset = offset % sector_size; 24 u32 sector = offset - sector_offset; 25 int err = 0; 26 27 /* code only supports updating a single sector */ 28 if (sector_offset + len > sector_size) 29 return -ENOSYS; 30 31 u8 *buffer = malloc(sector_size); 32 if (!buffer) 33 return -ENOMEM; 34 35 err = spi_flash_read_dm(dev, sector, sector_size, buffer); 36 if (err < 0) 37 goto out; 38 39 memcpy(buffer + sector_offset, buf, len); 40 41 err = spi_flash_erase_dm(dev, sector, sector_size); 42 if (err < 0) 43 goto out; 44 45 err = spi_flash_write_dm(dev, sector, sector_size, buffer); 46 if (err < 0) 47 goto out; 48 49out: 50 free(buffer); 51 return err; 52} 53 54static int bootcount_spi_flash_set(struct udevice *dev, const u32 a) 55{ 56 struct bootcount_spi_flash_priv *priv = dev_get_priv(dev); 57 const u16 val = bootcount_magic << 8 | (a & 0xff); 58 59 if (bootcount_spi_flash_update(priv->spi_flash, priv->offset, 2, &val) < 0) { 60 debug("%s: write failed\n", __func__); 61 return -EIO; 62 } 63 64 return 0; 65} 66 67static int bootcount_spi_flash_get(struct udevice *dev, u32 *a) 68{ 69 struct bootcount_spi_flash_priv *priv = dev_get_priv(dev); 70 u16 val; 71 72 if (spi_flash_read_dm(priv->spi_flash, priv->offset, 2, &val) < 0) { 73 debug("%s: read failed\n", __func__); 74 return -EIO; 75 } 76 77 if (val >> 8 == bootcount_magic) { 78 *a = val & 0xff; 79 return 0; 80 } 81 82 debug("%s: bootcount magic does not match on %04x\n", __func__, val); 83 return -EIO; 84} 85 86static int bootcount_spi_flash_probe(struct udevice *dev) 87{ 88 struct ofnode_phandle_args phandle_args; 89 struct bootcount_spi_flash_priv *priv = dev_get_priv(dev); 90 struct udevice *spi_flash; 91 92 if (dev_read_phandle_with_args(dev, "spi-flash", NULL, 0, 0, &phandle_args)) { 93 debug("%s: spi-flash backing device not specified\n", dev->name); 94 return -ENOENT; 95 } 96 97 if (uclass_get_device_by_ofnode(UCLASS_SPI_FLASH, phandle_args.node, &spi_flash)) { 98 debug("%s: could not get backing device\n", dev->name); 99 return -ENODEV; 100 } 101 102 priv->spi_flash = spi_flash; 103 priv->offset = dev_read_u32_default(dev, "offset", 0); 104 105 return 0; 106} 107 108static const struct bootcount_ops bootcount_spi_flash_ops = { 109 .get = bootcount_spi_flash_get, 110 .set = bootcount_spi_flash_set, 111}; 112 113static const struct udevice_id bootcount_spi_flash_ids[] = { 114 { .compatible = "u-boot,bootcount-spi-flash" }, 115 { } 116}; 117 118U_BOOT_DRIVER(bootcount_spi_flash) = { 119 .name = "bootcount-spi-flash", 120 .id = UCLASS_BOOTCOUNT, 121 .priv_auto = sizeof(struct bootcount_spi_flash_priv), 122 .probe = bootcount_spi_flash_probe, 123 .of_match = bootcount_spi_flash_ids, 124 .ops = &bootcount_spi_flash_ops, 125}; 126