mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-11-26 22:52:18 +00:00
482734aa66
This implements a driver using a RTC-based backing store for the DM bootcount implementation. The node configuring this feature will be compatible with 'u-boot,bootcount-rtc' and the underlying RTC device shall be reference through the property 'rtc'. An offset into the RTC device's register space can be provided through the 'offset' property. Tested on a RK3399-Q7 on a Flamingo carrier board using the SRAM area of the carrier board's RV3029 RTC. Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
89 lines
2 KiB
C
89 lines
2 KiB
C
// SPDX-License-Identifier: GPL-2.0+
|
|
/*
|
|
* (C) Copyright 2018 Theobroma Systems Design und Consulting GmbH
|
|
*/
|
|
|
|
#include <common.h>
|
|
#include <bootcount.h>
|
|
#include <dm.h>
|
|
#include <rtc.h>
|
|
|
|
static const u8 bootcount_magic = 0xbc;
|
|
|
|
struct bootcount_rtc_priv {
|
|
struct udevice *rtc;
|
|
u32 offset;
|
|
};
|
|
|
|
static int bootcount_rtc_set(struct udevice *dev, const u32 a)
|
|
{
|
|
struct bootcount_rtc_priv *priv = dev_get_priv(dev);
|
|
const u16 val = bootcount_magic << 8 | (a & 0xff);
|
|
|
|
if (rtc_write16(priv->rtc, priv->offset, val) < 0) {
|
|
debug("%s: rtc_write16 failed\n", __func__);
|
|
return -EIO;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int bootcount_rtc_get(struct udevice *dev, u32 *a)
|
|
{
|
|
struct bootcount_rtc_priv *priv = dev_get_priv(dev);
|
|
u16 val;
|
|
|
|
if (rtc_read16(priv->rtc, priv->offset, &val) < 0) {
|
|
debug("%s: rtc_write16 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_rtc_probe(struct udevice *dev)
|
|
{
|
|
struct ofnode_phandle_args phandle_args;
|
|
struct bootcount_rtc_priv *priv = dev_get_priv(dev);
|
|
struct udevice *rtc;
|
|
|
|
if (dev_read_phandle_with_args(dev, "rtc", NULL, 0, 0, &phandle_args)) {
|
|
debug("%s: rtc backing device not specified\n", dev->name);
|
|
return -ENOENT;
|
|
}
|
|
|
|
if (uclass_get_device_by_ofnode(UCLASS_RTC, phandle_args.node, &rtc)) {
|
|
debug("%s: could not get backing device\n", dev->name);
|
|
return -ENODEV;
|
|
}
|
|
|
|
priv->rtc = rtc;
|
|
priv->offset = dev_read_u32_default(dev, "offset", 0);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct bootcount_ops bootcount_rtc_ops = {
|
|
.get = bootcount_rtc_get,
|
|
.set = bootcount_rtc_set,
|
|
};
|
|
|
|
static const struct udevice_id bootcount_rtc_ids[] = {
|
|
{ .compatible = "u-boot,bootcount-rtc" },
|
|
{ }
|
|
};
|
|
|
|
U_BOOT_DRIVER(bootcount_rtc) = {
|
|
.name = "bootcount-rtc",
|
|
.id = UCLASS_BOOTCOUNT,
|
|
.priv_auto_alloc_size = sizeof(struct bootcount_rtc_priv),
|
|
.probe = bootcount_rtc_probe,
|
|
.of_match = bootcount_rtc_ids,
|
|
.ops = &bootcount_rtc_ops,
|
|
};
|