--- /dev/null
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2018-2022 Denx Software Engineering GmbH
+ * Heiko Schocher <hs@denx.de>
+ * Philip Oberfichtner <pro@denx.de>
+ *
+ * A bootcount driver using the registers MEMA - MEMD on the PFUZE100.
+ * This works only, if the PMIC is not connected.
+ */
+
+#include <common.h>
+#include <bootcount.h>
+#include <dm.h>
+#include <power/pmic.h>
+#include <power/pfuze100_pmic.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+#define PFUZE_BC_MAGIC 0xdead
+
+struct bootcount_pmic_priv {
+ struct udevice *pmic;
+};
+
+static int pfuze100_get_magic(struct udevice *dev, u32 *magic)
+{
+ int ret;
+
+ ret = pmic_reg_read(dev, PFUZE100_MEMA);
+ if (ret < 0)
+ return ret;
+ *magic = ret;
+
+ ret = pmic_reg_read(dev, PFUZE100_MEMB);
+ if (ret < 0)
+ return ret;
+ *magic += ret << 8;
+
+ return 0;
+}
+
+static int pfuze100_set_magic(struct udevice *dev)
+{
+ int ret;
+
+ ret = pmic_reg_write(dev, PFUZE100_MEMA, PFUZE_BC_MAGIC & 0xff);
+ if (ret)
+ return ret;
+
+ ret = pmic_reg_write(dev, PFUZE100_MEMB, (PFUZE_BC_MAGIC >> 8) & 0xff);
+ return ret;
+}
+
+static int pfuze100_get_value(struct udevice *dev, u32 *a)
+{
+ int ret;
+
+ ret = pmic_reg_read(dev, PFUZE100_MEMC);
+ if (ret < 0)
+ return ret;
+ *a = ret;
+
+ ret = pmic_reg_read(dev, PFUZE100_MEMD);
+ if (ret < 0)
+ return ret;
+ *a += ret << 8;
+
+ return 0;
+}
+
+static int pfuze100_set_value(struct udevice *dev, u32 val)
+{
+ int ret;
+
+ ret = pmic_reg_write(dev, PFUZE100_MEMC, val & 0xff);
+ if (ret)
+ return ret;
+
+ ret = pmic_reg_write(dev, PFUZE100_MEMD, (val >> 8) & 0xff);
+ return ret;
+}
+
+static int bootcount_pmic_set(struct udevice *dev, const u32 a)
+{
+ struct bootcount_pmic_priv *priv = dev_get_priv(dev);
+
+ if (pfuze100_set_magic(priv->pmic)) {
+ debug("%s: writing magic failed\n", __func__);
+ return -EIO;
+ }
+
+ if (pfuze100_set_value(priv->pmic, a)) {
+ debug("%s: writing value failed\n", __func__);
+ return -EIO;
+ }
+
+ return 0;
+}
+
+static int bootcount_pmic_get(struct udevice *dev, u32 *a)
+{
+ struct bootcount_pmic_priv *priv = dev_get_priv(dev);
+ u32 magic;
+
+ if (pfuze100_get_magic(priv->pmic, &magic)) {
+ debug("%s: reading magic failed\n", __func__);
+ return -EIO;
+ }
+
+ if (magic != PFUZE_BC_MAGIC) {
+ *a = 0;
+ return 0;
+ }
+
+ if (pfuze100_get_value(priv->pmic, a)) {
+ debug("%s: reading value failed\n", __func__);
+ return -EIO;
+ }
+
+ return 0;
+}
+
+static int bootcount_pmic_probe(struct udevice *dev)
+{
+ struct ofnode_phandle_args phandle_args;
+ struct bootcount_pmic_priv *priv = dev_get_priv(dev);
+ struct udevice *pmic;
+
+ if (dev_read_phandle_with_args(dev, "pmic", NULL, 0, 0, &phandle_args)) {
+ debug("%s: pmic backing device not specified\n", dev->name);
+ return -ENOENT;
+ }
+
+ if (uclass_get_device_by_ofnode(UCLASS_PMIC, phandle_args.node, &pmic)) {
+ debug("%s: could not get backing device\n", dev->name);
+ return -ENODEV;
+ }
+
+ priv->pmic = pmic;
+
+ return 0;
+}
+
+static const struct bootcount_ops bootcount_pmic_ops = {
+ .get = bootcount_pmic_get,
+ .set = bootcount_pmic_set,
+};
+
+static const struct udevice_id bootcount_pmic_ids[] = {
+ { .compatible = "u-boot,bootcount-pmic" },
+ { }
+};
+
+U_BOOT_DRIVER(bootcount_pmic) = {
+ .name = "bootcount-pmic",
+ .id = UCLASS_BOOTCOUNT,
+ .priv_auto = sizeof(struct bootcount_pmic_priv),
+ .probe = bootcount_pmic_probe,
+ .of_match = bootcount_pmic_ids,
+ .ops = &bootcount_pmic_ops,
+};