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
12 static const u8 bootcount_magic = 0xbc;
13
14 struct bootcount_spi_flash_priv {
15 struct udevice *spi_flash;
16 u32 offset;
17 };
18
bootcount_spi_flash_update(struct udevice * dev,u32 offset,u32 len,const void * buf)19 static 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
49 out:
50 free(buffer);
51 return err;
52 }
53
bootcount_spi_flash_set(struct udevice * dev,const u32 a)54 static 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
bootcount_spi_flash_get(struct udevice * dev,u32 * a)67 static 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
bootcount_spi_flash_probe(struct udevice * dev)86 static 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
108 static const struct bootcount_ops bootcount_spi_flash_ops = {
109 .get = bootcount_spi_flash_get,
110 .set = bootcount_spi_flash_set,
111 };
112
113 static const struct udevice_id bootcount_spi_flash_ids[] = {
114 { .compatible = "u-boot,bootcount-spi-flash" },
115 { }
116 };
117
118 U_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