1 files changed, 114 insertions, 0 deletions
diff --git a/drivers/reset/reset-oxnas.c b/drivers/reset/reset-oxnas.c
new file mode 100644
index 000000000..8209f922d
--- /dev/null
+++ b/drivers/reset/reset-oxnas.c
@@ -0,0 +1,114 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Oxford Semiconductor Reset Controller driver
+ *
+ * Copyright (C) 2016 Neil Armstrong <narmstrong@baylibre.com>
+ * Copyright (C) 2014 Ma Haijun <mahaijuns@gmail.com>
+ * Copyright (C) 2009 Oxford Semiconductor Ltd
+ */
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/reset-controller.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/types.h>
+#include <linux/regmap.h>
+#include <linux/mfd/syscon.h>
+
+/* Regmap offsets */
+#define RST_SET_REGOFFSET	0x34
+#define RST_CLR_REGOFFSET	0x38
+
+struct oxnas_reset {
+	struct regmap *regmap;
+	struct reset_controller_dev rcdev;
+};
+
+static int oxnas_reset_reset(struct reset_controller_dev *rcdev,
+			      unsigned long id)
+{
+	struct oxnas_reset *data =
+		container_of(rcdev, struct oxnas_reset, rcdev);
+
+	regmap_write(data->regmap, RST_SET_REGOFFSET, BIT(id));
+	msleep(50);
+	regmap_write(data->regmap, RST_CLR_REGOFFSET, BIT(id));
+
+	return 0;
+}
+
+static int oxnas_reset_assert(struct reset_controller_dev *rcdev,
+			      unsigned long id)
+{
+	struct oxnas_reset *data =
+		container_of(rcdev, struct oxnas_reset, rcdev);
+
+	regmap_write(data->regmap, RST_SET_REGOFFSET, BIT(id));
+
+	return 0;
+}
+
+static int oxnas_reset_deassert(struct reset_controller_dev *rcdev,
+				unsigned long id)
+{
+	struct oxnas_reset *data =
+		container_of(rcdev, struct oxnas_reset, rcdev);
+
+	regmap_write(data->regmap, RST_CLR_REGOFFSET, BIT(id));
+
+	return 0;
+}
+
+static const struct reset_control_ops oxnas_reset_ops = {
+	.reset		= oxnas_reset_reset,
+	.assert		= oxnas_reset_assert,
+	.deassert	= oxnas_reset_deassert,
+};
+
+static const struct of_device_id oxnas_reset_dt_ids[] = {
+	 { .compatible = "oxsemi,ox810se-reset", },
+	 { .compatible = "oxsemi,ox820-reset", },
+	 { /* sentinel */ },
+};
+
+static int oxnas_reset_probe(struct platform_device *pdev)
+{
+	struct oxnas_reset *data;
+	struct device *parent;
+
+	parent = pdev->dev.parent;
+	if (!parent) {
+		dev_err(&pdev->dev, "no parent\n");
+		return -ENODEV;
+	}
+
+	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->regmap = syscon_node_to_regmap(parent->of_node);
+	if (IS_ERR(data->regmap)) {
+		dev_err(&pdev->dev, "failed to get parent regmap\n");
+		return PTR_ERR(data->regmap);
+	}
+
+	platform_set_drvdata(pdev, data);
+
+	data->rcdev.owner = THIS_MODULE;
+	data->rcdev.nr_resets = 32;
+	data->rcdev.ops = &oxnas_reset_ops;
+	data->rcdev.of_node = pdev->dev.of_node;
+
+	return devm_reset_controller_register(&pdev->dev, &data->rcdev);
+}
+
+static struct platform_driver oxnas_reset_driver = {
+	.probe	= oxnas_reset_probe,
+	.driver = {
+		.name		= "oxnas-reset",
+		.of_match_table	= oxnas_reset_dt_ids,
+	},
+};
+builtin_platform_driver(oxnas_reset_driver);