1 files changed, 145 insertions, 0 deletions
diff --git a/drivers/reset/reset-meson.c b/drivers/reset/reset-meson.c
new file mode 100644
index 000000000..94d7ba88d
--- /dev/null
+++ b/drivers/reset/reset-meson.c
@@ -0,0 +1,145 @@
+// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+/*
+ * Amlogic Meson Reset Controller driver
+ *
+ * Copyright (c) 2016 BayLibre, SAS.
+ * Author: Neil Armstrong <narmstrong@baylibre.com>
+ */
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/reset-controller.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/of_device.h>
+
+#define BITS_PER_REG	32
+
+struct meson_reset_param {
+	int reg_count;
+	int level_offset;
+};
+
+struct meson_reset {
+	void __iomem *reg_base;
+	const struct meson_reset_param *param;
+	struct reset_controller_dev rcdev;
+	spinlock_t lock;
+};
+
+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 bank = id / BITS_PER_REG;
+	unsigned int offset = id % BITS_PER_REG;
+	void __iomem *reg_addr = data->reg_base + (bank << 2);
+
+	writel(BIT(offset), reg_addr);
+
+	return 0;
+}
+
+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 bank = id / BITS_PER_REG;
+	unsigned int offset = id % BITS_PER_REG;
+	void __iomem *reg_addr;
+	unsigned long flags;
+	u32 reg;
+
+	reg_addr = data->reg_base + data->param->level_offset + (bank << 2);
+
+	spin_lock_irqsave(&data->lock, flags);
+
+	reg = readl(reg_addr);
+	if (assert)
+		writel(reg & ~BIT(offset), reg_addr);
+	else
+		writel(reg | BIT(offset), reg_addr);
+
+	spin_unlock_irqrestore(&data->lock, flags);
+
+	return 0;
+}
+
+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 const struct reset_control_ops meson_reset_ops = {
+	.reset		= meson_reset_reset,
+	.assert		= meson_reset_assert,
+	.deassert	= meson_reset_deassert,
+};
+
+static const struct meson_reset_param meson8b_param = {
+	.reg_count	= 8,
+	.level_offset	= 0x7c,
+};
+
+static const struct meson_reset_param meson_a1_param = {
+	.reg_count	= 3,
+	.level_offset	= 0x40,
+};
+
+static const struct of_device_id meson_reset_dt_ids[] = {
+	 { .compatible = "amlogic,meson8b-reset",    .data = &meson8b_param},
+	 { .compatible = "amlogic,meson-gxbb-reset", .data = &meson8b_param},
+	 { .compatible = "amlogic,meson-axg-reset",  .data = &meson8b_param},
+	 { .compatible = "amlogic,meson-a1-reset",   .data = &meson_a1_param},
+	 { /* sentinel */ },
+};
+
+static int meson_reset_probe(struct platform_device *pdev)
+{
+	struct meson_reset *data;
+	struct resource *res;
+
+	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	data->reg_base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(data->reg_base))
+		return PTR_ERR(data->reg_base);
+
+	data->param = of_device_get_match_data(&pdev->dev);
+	if (!data->param)
+		return -ENODEV;
+
+	platform_set_drvdata(pdev, data);
+
+	spin_lock_init(&data->lock);
+
+	data->rcdev.owner = THIS_MODULE;
+	data->rcdev.nr_resets = data->param->reg_count * BITS_PER_REG;
+	data->rcdev.ops = &meson_reset_ops;
+	data->rcdev.of_node = pdev->dev.of_node;
+
+	return devm_reset_controller_register(&pdev->dev, &data->rcdev);
+}
+
+static struct platform_driver meson_reset_driver = {
+	.probe	= meson_reset_probe,
+	.driver = {
+		.name		= "meson_reset",
+		.of_match_table	= meson_reset_dt_ids,
+	},
+};
+builtin_platform_driver(meson_reset_driver);