1 files changed, 142 insertions, 0 deletions
diff --git a/drivers/reset/amlogic/reset-meson-common.c b/drivers/reset/amlogic/reset-meson-common.c
new file mode 100644
index 000000000000..38a767c06fc7
--- /dev/null
+++ b/drivers/reset/amlogic/reset-meson-common.c
@@ -0,0 +1,142 @@
+// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+/*
+ * Amlogic Meson Reset core functions
+ *
+ * Copyright (c) 2016-2024 BayLibre, SAS.
+ * Authors: Neil Armstrong <narmstrong@baylibre.com>
+ *          Jerome Brunet <jbrunet@baylibre.com>
+ */
+
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/reset-controller.h>
+
+#include "reset-meson.h"
+
+struct meson_reset {
+	const struct meson_reset_param *param;
+	struct reset_controller_dev rcdev;
+	struct regmap *map;
+};
+
+static void meson_reset_offset_and_bit(struct meson_reset *data,
+				       unsigned long id,
+				       unsigned int *offset,
+				       unsigned int *bit)
+{
+	unsigned int stride = regmap_get_reg_stride(data->map);
+
+	*offset = (id / (stride * BITS_PER_BYTE)) * stride;
+	*bit = id % (stride * BITS_PER_BYTE);
+}
+
+static int meson_reset_reset(struct reset_controller_dev *rcdev,
+			     unsigned long id)
+{
+	struct meson_reset *data =
+		container_of(rcdev, struct meson_reset, rcdev);
+	unsigned int offset, bit;
+
+	meson_reset_offset_and_bit(data, id, &offset, &bit);
+	offset += data->param->reset_offset;
+
+	return regmap_write(data->map, offset, BIT(bit));
+}
+
+static int meson_reset_level(struct reset_controller_dev *rcdev,
+			     unsigned long id, bool assert)
+{
+	struct meson_reset *data =
+		container_of(rcdev, struct meson_reset, rcdev);
+	unsigned int offset, bit;
+
+	meson_reset_offset_and_bit(data, id, &offset, &bit);
+	offset += data->param->level_offset;
+	assert ^= data->param->level_low_reset;
+
+	return regmap_update_bits(data->map, offset,
+				  BIT(bit), assert ? BIT(bit) : 0);
+}
+
+static int meson_reset_status(struct reset_controller_dev *rcdev,
+			      unsigned long id)
+{
+	struct meson_reset *data =
+		container_of(rcdev, struct meson_reset, rcdev);
+	unsigned int val, offset, bit;
+
+	meson_reset_offset_and_bit(data, id, &offset, &bit);
+	offset += data->param->level_offset;
+
+	regmap_read(data->map, offset, &val);
+	val = !!(BIT(bit) & val);
+
+	return val ^ data->param->level_low_reset;
+}
+
+static int meson_reset_assert(struct reset_controller_dev *rcdev,
+			      unsigned long id)
+{
+	return meson_reset_level(rcdev, id, true);
+}
+
+static int meson_reset_deassert(struct reset_controller_dev *rcdev,
+				unsigned long id)
+{
+	return meson_reset_level(rcdev, id, false);
+}
+
+static int meson_reset_level_toggle(struct reset_controller_dev *rcdev,
+				    unsigned long id)
+{
+	int ret;
+
+	ret = meson_reset_assert(rcdev, id);
+	if (ret)
+		return ret;
+
+	return meson_reset_deassert(rcdev, id);
+}
+
+const struct reset_control_ops meson_reset_ops = {
+	.reset		= meson_reset_reset,
+	.assert		= meson_reset_assert,
+	.deassert	= meson_reset_deassert,
+	.status		= meson_reset_status,
+};
+EXPORT_SYMBOL_NS_GPL(meson_reset_ops, MESON_RESET);
+
+const struct reset_control_ops meson_reset_toggle_ops = {
+	.reset		= meson_reset_level_toggle,
+	.assert		= meson_reset_assert,
+	.deassert	= meson_reset_deassert,
+	.status		= meson_reset_status,
+};
+EXPORT_SYMBOL_NS_GPL(meson_reset_toggle_ops, MESON_RESET);
+
+int meson_reset_controller_register(struct device *dev, struct regmap *map,
+				    const struct meson_reset_param *param)
+{
+	struct meson_reset *data;
+
+	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->param = param;
+	data->map = map;
+	data->rcdev.owner = dev->driver->owner;
+	data->rcdev.nr_resets = param->reset_num;
+	data->rcdev.ops = data->param->reset_ops;
+	data->rcdev.of_node = dev->of_node;
+
+	return devm_reset_controller_register(dev, &data->rcdev);
+}
+EXPORT_SYMBOL_NS_GPL(meson_reset_controller_register, MESON_RESET);
+
+MODULE_DESCRIPTION("Amlogic Meson Reset Core function");
+MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
+MODULE_AUTHOR("Jerome Brunet <jbrunet@baylibre.com>");
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_IMPORT_NS(MESON_RESET);