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path: root/drivers/clk/visconti/reset.c
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Diffstat (limited to 'drivers/clk/visconti/reset.c')
-rw-r--r--drivers/clk/visconti/reset.c107
1 files changed, 107 insertions, 0 deletions
diff --git a/drivers/clk/visconti/reset.c b/drivers/clk/visconti/reset.c
new file mode 100644
index 0000000000..e3c3d78046
--- /dev/null
+++ b/drivers/clk/visconti/reset.c
@@ -0,0 +1,107 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Toshiba Visconti ARM SoC reset controller
+ *
+ * Copyright (c) 2021 TOSHIBA CORPORATION
+ * Copyright (c) 2021 Toshiba Electronic Devices & Storage Corporation
+ *
+ * Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
+ */
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#include "reset.h"
+
+static inline struct visconti_reset *to_visconti_reset(struct reset_controller_dev *rcdev)
+{
+ return container_of(rcdev, struct visconti_reset, rcdev);
+}
+
+static int visconti_reset_assert(struct reset_controller_dev *rcdev, unsigned long id)
+{
+ struct visconti_reset *reset = to_visconti_reset(rcdev);
+ const struct visconti_reset_data *data = &reset->resets[id];
+ u32 rst = BIT(data->rs_idx);
+ unsigned long flags;
+ int ret;
+
+ spin_lock_irqsave(reset->lock, flags);
+ ret = regmap_update_bits(reset->regmap, data->rson_offset, rst, rst);
+ spin_unlock_irqrestore(reset->lock, flags);
+
+ return ret;
+}
+
+static int visconti_reset_deassert(struct reset_controller_dev *rcdev, unsigned long id)
+{
+ struct visconti_reset *reset = to_visconti_reset(rcdev);
+ const struct visconti_reset_data *data = &reset->resets[id];
+ u32 rst = BIT(data->rs_idx);
+ unsigned long flags;
+ int ret;
+
+ spin_lock_irqsave(reset->lock, flags);
+ ret = regmap_update_bits(reset->regmap, data->rsoff_offset, rst, rst);
+ spin_unlock_irqrestore(reset->lock, flags);
+
+ return ret;
+}
+
+static int visconti_reset_reset(struct reset_controller_dev *rcdev, unsigned long id)
+{
+ visconti_reset_assert(rcdev, id);
+ udelay(1);
+ visconti_reset_deassert(rcdev, id);
+
+ return 0;
+}
+
+static int visconti_reset_status(struct reset_controller_dev *rcdev, unsigned long id)
+{
+ struct visconti_reset *reset = to_visconti_reset(rcdev);
+ const struct visconti_reset_data *data = &reset->resets[id];
+ unsigned long flags;
+ u32 reg;
+ int ret;
+
+ spin_lock_irqsave(reset->lock, flags);
+ ret = regmap_read(reset->regmap, data->rson_offset, &reg);
+ spin_unlock_irqrestore(reset->lock, flags);
+ if (ret)
+ return ret;
+
+ return !(reg & data->rs_idx);
+}
+
+const struct reset_control_ops visconti_reset_ops = {
+ .assert = visconti_reset_assert,
+ .deassert = visconti_reset_deassert,
+ .reset = visconti_reset_reset,
+ .status = visconti_reset_status,
+};
+
+int visconti_register_reset_controller(struct device *dev,
+ struct regmap *regmap,
+ const struct visconti_reset_data *resets,
+ unsigned int num_resets,
+ const struct reset_control_ops *reset_ops,
+ spinlock_t *lock)
+{
+ struct visconti_reset *reset;
+
+ reset = devm_kzalloc(dev, sizeof(*reset), GFP_KERNEL);
+ if (!reset)
+ return -ENOMEM;
+
+ reset->regmap = regmap;
+ reset->resets = resets;
+ reset->rcdev.ops = reset_ops;
+ reset->rcdev.nr_resets = num_resets;
+ reset->rcdev.of_node = dev->of_node;
+ reset->lock = lock;
+
+ return devm_reset_controller_register(dev, &reset->rcdev);
+}