1 files changed, 135 insertions, 0 deletions
diff --git a/drivers/reset/reset-th1520.c b/drivers/reset/reset-th1520.c
new file mode 100644
index 000000000000..7874f0693e1b
--- /dev/null
+++ b/drivers/reset/reset-th1520.c
@@ -0,0 +1,135 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2024 Samsung Electronics Co., Ltd.
+ * Author: Michal Wilczynski <m.wilczynski@samsung.com>
+ */
+
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/reset-controller.h>
+#include <linux/regmap.h>
+
+#include <dt-bindings/reset/thead,th1520-reset.h>
+
+ /* register offset in VOSYS_REGMAP */
+#define TH1520_GPU_RST_CFG		0x0
+#define TH1520_GPU_RST_CFG_MASK		GENMASK(1, 0)
+
+/* register values */
+#define TH1520_GPU_SW_GPU_RST		BIT(0)
+#define TH1520_GPU_SW_CLKGEN_RST	BIT(1)
+
+struct th1520_reset_priv {
+	struct reset_controller_dev rcdev;
+	struct regmap *map;
+};
+
+struct th1520_reset_map {
+	u32 bit;
+	u32 reg;
+};
+
+static const struct th1520_reset_map th1520_resets[] = {
+	[TH1520_RESET_ID_GPU] = {
+		.bit = TH1520_GPU_SW_GPU_RST,
+		.reg = TH1520_GPU_RST_CFG,
+	},
+	[TH1520_RESET_ID_GPU_CLKGEN] = {
+		.bit = TH1520_GPU_SW_CLKGEN_RST,
+		.reg = TH1520_GPU_RST_CFG,
+	}
+};
+
+static inline struct th1520_reset_priv *
+to_th1520_reset(struct reset_controller_dev *rcdev)
+{
+	return container_of(rcdev, struct th1520_reset_priv, rcdev);
+}
+
+static int th1520_reset_assert(struct reset_controller_dev *rcdev,
+			       unsigned long id)
+{
+	struct th1520_reset_priv *priv = to_th1520_reset(rcdev);
+	const struct th1520_reset_map *reset;
+
+	reset = &th1520_resets[id];
+
+	return regmap_update_bits(priv->map, reset->reg, reset->bit, 0);
+}
+
+static int th1520_reset_deassert(struct reset_controller_dev *rcdev,
+				 unsigned long id)
+{
+	struct th1520_reset_priv *priv = to_th1520_reset(rcdev);
+	const struct th1520_reset_map *reset;
+
+	reset = &th1520_resets[id];
+
+	return regmap_update_bits(priv->map, reset->reg, reset->bit,
+				  reset->bit);
+}
+
+static const struct reset_control_ops th1520_reset_ops = {
+	.assert	= th1520_reset_assert,
+	.deassert = th1520_reset_deassert,
+};
+
+static const struct regmap_config th1520_reset_regmap_config = {
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_stride = 4,
+	.fast_io = true,
+};
+
+static int th1520_reset_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct th1520_reset_priv *priv;
+	void __iomem *base;
+	int ret;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	priv->map = devm_regmap_init_mmio(dev, base,
+					  &th1520_reset_regmap_config);
+	if (IS_ERR(priv->map))
+		return PTR_ERR(priv->map);
+
+	/* Initialize GPU resets to asserted state */
+	ret = regmap_update_bits(priv->map, TH1520_GPU_RST_CFG,
+				 TH1520_GPU_RST_CFG_MASK, 0);
+	if (ret)
+		return ret;
+
+	priv->rcdev.owner = THIS_MODULE;
+	priv->rcdev.nr_resets = ARRAY_SIZE(th1520_resets);
+	priv->rcdev.ops = &th1520_reset_ops;
+	priv->rcdev.of_node = dev->of_node;
+
+	return devm_reset_controller_register(dev, &priv->rcdev);
+}
+
+static const struct of_device_id th1520_reset_match[] = {
+	{ .compatible = "thead,th1520-reset" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, th1520_reset_match);
+
+static struct platform_driver th1520_reset_driver = {
+	.driver = {
+		.name = "th1520-reset",
+		.of_match_table = th1520_reset_match,
+	},
+	.probe = th1520_reset_probe,
+};
+module_platform_driver(th1520_reset_driver);
+
+MODULE_AUTHOR("Michal Wilczynski <m.wilczynski@samsung.com>");
+MODULE_DESCRIPTION("T-HEAD TH1520 SoC reset controller");
+MODULE_LICENSE("GPL");