1 files changed, 92 insertions, 0 deletions
diff --git a/drivers/reset/stm32/stm32-reset-core.c b/drivers/reset/stm32/stm32-reset-core.c
new file mode 100644
index 00000000000..7dd92e07e1a
--- /dev/null
+++ b/drivers/reset/stm32/stm32-reset-core.c
@@ -0,0 +1,92 @@
+// SPDX-License-Identifier: GPL-2.0-or-later OR BSD-3-Clause
+/*
+ * Copyright (C) 2024, STMicroelectronics - All Rights Reserved
+ * Author(s): Gabriel Fernandez, <gabriel.fernandez@foss.st.com> for STMicroelectronics.
+ */
+
+#include <dm.h>
+#include <reset-uclass.h>
+#include <stm32-reset-core.h>
+#include <stm32_rcc.h>
+#include <dm/device_compat.h>
+#include <linux/iopoll.h>
+
+static int stm32_reset_update(struct reset_ctl *reset_ctl, bool status)
+{
+	struct stm32_reset_priv *priv = dev_get_priv(reset_ctl->dev);
+	const struct stm32_reset_data *data = priv->data;
+	const struct stm32_reset_cfg *ptr_line;
+	fdt_addr_t addr;
+
+	assert(priv->data->get_reset_line);
+
+	ptr_line = priv->data->get_reset_line(reset_ctl);
+	if (!ptr_line)
+		return -EPERM;
+
+	addr = priv->base + ptr_line->offset;
+
+	dev_dbg(reset_ctl->dev, "reset id=%ld offset=0x%x bit=%d status=%d\n",
+		reset_ctl->id, ptr_line->offset, ptr_line->bit_idx, status);
+
+	status = ptr_line->inverted ^ status;
+
+	if (ptr_line->set_clr) {
+		if (!status)
+			addr += data->clear_offset;
+
+		writel(BIT(ptr_line->bit_idx), addr);
+
+	} else {
+		if (status)
+			setbits_le32(addr, BIT(ptr_line->bit_idx));
+		else
+			clrbits_le32(addr, BIT(ptr_line->bit_idx));
+	}
+
+	/* Check deassert */
+	if (!status) {
+		u32 reg;
+
+		return readl_poll_timeout(addr, reg,
+					  !(reg & BIT(ptr_line->bit_idx)),
+					  data->reset_us);
+	}
+
+	return 0;
+}
+
+static int stm32_reset_assert(struct reset_ctl *reset_ctl)
+{
+	return stm32_reset_update(reset_ctl, true);
+}
+
+static int stm32_reset_deassert(struct reset_ctl *reset_ctl)
+{
+	return stm32_reset_update(reset_ctl, false);
+}
+
+const struct reset_ops stm32_reset_ops = {
+	.rst_assert	= stm32_reset_assert,
+	.rst_deassert	= stm32_reset_deassert,
+};
+
+int stm32_reset_core_probe(struct udevice *dev,
+			   const struct stm32_reset_data *data)
+{
+	struct stm32_reset_priv *priv = dev_get_priv(dev);
+
+	priv->base = dev_read_addr(dev);
+	if (priv->base == FDT_ADDR_T_NONE) {
+		/* for MFD, get address of parent */
+		priv->base = dev_read_addr(dev->parent);
+		if (priv->base == FDT_ADDR_T_NONE)
+			return -EINVAL;
+	}
+
+	priv->data = data;
+
+	assert(priv->data);
+
+	return 0;
+}