u-boot/drivers/bootcount/i2c-eeprom.c
Robert Beckett ae3d38f318 bootcount: add a DM i2c eeprom backing store for bootcount
This driver allows the use of i2c eeprom device or partition as backing
store for boot counter values with DM enabled.

Signed-off-by: Robert Beckett <bob.beckett@collabora.com>
2020-01-10 10:25:13 -05:00

96 lines
2.2 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* (C) Copyright 2019 Collabora
* (C) Copyright 2019 GE
*/
#include <common.h>
#include <bootcount.h>
#include <dm.h>
#include <i2c_eeprom.h>
static const u8 bootcount_magic = 0xbc;
struct bootcount_i2c_eeprom_priv {
struct udevice *i2c_eeprom;
u32 offset;
};
static int bootcount_i2c_eeprom_set(struct udevice *dev, const u32 a)
{
struct bootcount_i2c_eeprom_priv *priv = dev_get_priv(dev);
const u16 val = bootcount_magic << 8 | (a & 0xff);
if (i2c_eeprom_write(priv->i2c_eeprom, priv->offset,
(uint8_t *)&val, 2) < 0) {
debug("%s: write failed\n", __func__);
return -EIO;
}
return 0;
}
static int bootcount_i2c_eeprom_get(struct udevice *dev, u32 *a)
{
struct bootcount_i2c_eeprom_priv *priv = dev_get_priv(dev);
u16 val;
if (i2c_eeprom_read(priv->i2c_eeprom, priv->offset,
(uint8_t *)&val, 2) < 0) {
debug("%s: read failed\n", __func__);
return -EIO;
}
if (val >> 8 == bootcount_magic) {
*a = val & 0xff;
return 0;
}
debug("%s: bootcount magic does not match on %04x\n", __func__, val);
return -EIO;
}
static int bootcount_i2c_eeprom_probe(struct udevice *dev)
{
struct ofnode_phandle_args phandle_args;
struct bootcount_i2c_eeprom_priv *priv = dev_get_priv(dev);
struct udevice *i2c_eeprom;
if (dev_read_phandle_with_args(dev, "i2c-eeprom", NULL, 0, 0,
&phandle_args)) {
debug("%s: i2c-eeprom backing device not specified\n",
dev->name);
return -ENOENT;
}
if (uclass_get_device_by_ofnode(UCLASS_I2C_EEPROM, phandle_args.node,
&i2c_eeprom)) {
debug("%s: could not get backing device\n", dev->name);
return -ENODEV;
}
priv->i2c_eeprom = i2c_eeprom;
priv->offset = dev_read_u32_default(dev, "offset", 0);
return 0;
}
static const struct bootcount_ops bootcount_i2c_eeprom_ops = {
.get = bootcount_i2c_eeprom_get,
.set = bootcount_i2c_eeprom_set,
};
static const struct udevice_id bootcount_i2c_eeprom_ids[] = {
{ .compatible = "u-boot,bootcount-i2c-eeprom" },
{ }
};
U_BOOT_DRIVER(bootcount_spi_flash) = {
.name = "bootcount-i2c-eeprom",
.id = UCLASS_BOOTCOUNT,
.priv_auto_alloc_size = sizeof(struct bootcount_i2c_eeprom_priv),
.probe = bootcount_i2c_eeprom_probe,
.of_match = bootcount_i2c_eeprom_ids,
.ops = &bootcount_i2c_eeprom_ops,
};