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"Das U-Boot" Source Tree
1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * (C) Copyright 2019 Collabora
4 * (C) Copyright 2019 GE
5 */
6
7#include <bootcount.h>
8#include <dm.h>
9#include <i2c_eeprom.h>
10#include <log.h>
11
12static const u8 bootcount_magic = 0xbc;
13
14struct bootcount_i2c_eeprom_priv {
15 struct udevice *i2c_eeprom;
16 u32 offset;
17};
18
19static int bootcount_i2c_eeprom_set(struct udevice *dev, const u32 a)
20{
21 struct bootcount_i2c_eeprom_priv *priv = dev_get_priv(dev);
22 const u16 val = bootcount_magic << 8 | (a & 0xff);
23
24 if (i2c_eeprom_write(priv->i2c_eeprom, priv->offset,
25 (uint8_t *)&val, 2) < 0) {
26 debug("%s: write failed\n", __func__);
27 return -EIO;
28 }
29
30 return 0;
31}
32
33static int bootcount_i2c_eeprom_get(struct udevice *dev, u32 *a)
34{
35 struct bootcount_i2c_eeprom_priv *priv = dev_get_priv(dev);
36 u16 val;
37
38 if (i2c_eeprom_read(priv->i2c_eeprom, priv->offset,
39 (uint8_t *)&val, 2) < 0) {
40 debug("%s: read failed\n", __func__);
41 return -EIO;
42 }
43
44 if (val >> 8 == bootcount_magic) {
45 *a = val & 0xff;
46 return 0;
47 }
48
49 debug("%s: bootcount magic does not match on %04x\n", __func__, val);
50 return -EIO;
51}
52
53static int bootcount_i2c_eeprom_probe(struct udevice *dev)
54{
55 struct ofnode_phandle_args phandle_args;
56 struct bootcount_i2c_eeprom_priv *priv = dev_get_priv(dev);
57 struct udevice *i2c_eeprom;
58
59 if (dev_read_phandle_with_args(dev, "i2c-eeprom", NULL, 0, 0,
60 &phandle_args)) {
61 debug("%s: i2c-eeprom backing device not specified\n",
62 dev->name);
63 return -ENOENT;
64 }
65
66 if (uclass_get_device_by_ofnode(UCLASS_I2C_EEPROM, phandle_args.node,
67 &i2c_eeprom)) {
68 debug("%s: could not get backing device\n", dev->name);
69 return -ENODEV;
70 }
71
72 priv->i2c_eeprom = i2c_eeprom;
73 priv->offset = dev_read_u32_default(dev, "offset", 0);
74
75 return 0;
76}
77
78static const struct bootcount_ops bootcount_i2c_eeprom_ops = {
79 .get = bootcount_i2c_eeprom_get,
80 .set = bootcount_i2c_eeprom_set,
81};
82
83static const struct udevice_id bootcount_i2c_eeprom_ids[] = {
84 { .compatible = "u-boot,bootcount-i2c-eeprom" },
85 { }
86};
87
88U_BOOT_DRIVER(bootcount_spi_flash) = {
89 .name = "bootcount-i2c-eeprom",
90 .id = UCLASS_BOOTCOUNT,
91 .priv_auto = sizeof(struct bootcount_i2c_eeprom_priv),
92 .probe = bootcount_i2c_eeprom_probe,
93 .of_match = bootcount_i2c_eeprom_ids,
94 .ops = &bootcount_i2c_eeprom_ops,
95};