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-rw-r--r--drivers/reset/reset-meson.c152
1 files changed, 152 insertions, 0 deletions
diff --git a/drivers/reset/reset-meson.c b/drivers/reset/reset-meson.c
new file mode 100644
index 0000000000..a7af051b17
--- /dev/null
+++ b/drivers/reset/reset-meson.c
@@ -0,0 +1,152 @@
+// 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/module.h>
+#include <linux/platform_device.h>
+#include <linux/reset-controller.h>
+#include <linux/slab.h>
+#include <linux/types.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 meson_reset_param meson_s4_param = {
+ .reg_count = 6,
+ .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},
+ { .compatible = "amlogic,meson-s4-reset", .data = &meson_s4_param},
+ { /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, meson_reset_dt_ids);
+
+static int meson_reset_probe(struct platform_device *pdev)
+{
+ struct meson_reset *data;
+
+ data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ data->reg_base = devm_platform_ioremap_resource(pdev, 0);
+ 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;
+
+ 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,
+ },
+};
+module_platform_driver(meson_reset_driver);
+
+MODULE_DESCRIPTION("Amlogic Meson Reset Controller driver");
+MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
+MODULE_LICENSE("Dual BSD/GPL");