GK SDK 源码库: XMIPCLinuxV100R005C00SPC030 (kernel/tools/open_source excluded)

source/bootloader/u-boot-2020.01/drivers/bootcount/rtc.c

@@ -0,0 +1,89 @@
+// 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,
+};