drivers/clk/mediatek/reset.c

Source file repositories/reference/linux-study-clean/drivers/clk/mediatek/reset.c

File Facts

System
Linux kernel
Corpus path
drivers/clk/mediatek/reset.c
Extension
.c
Size
4290 bytes
Lines
175
Domain
Driver Families
Bucket
drivers/clk
Inferred role
Driver Families: exported/initcall integration point
Status
integration implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2014 MediaTek Inc.
 */

#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/slab.h>

#include "reset.h"

static inline struct mtk_clk_rst_data *to_mtk_clk_rst_data(struct reset_controller_dev *rcdev)
{
	return container_of(rcdev, struct mtk_clk_rst_data, rcdev);
}

static int mtk_reset_update(struct reset_controller_dev *rcdev,
			    unsigned long id, bool deassert)
{
	struct mtk_clk_rst_data *data = to_mtk_clk_rst_data(rcdev);
	unsigned int val = deassert ? 0 : ~0;

	return regmap_update_bits(data->regmap,
				  data->desc->rst_bank_ofs[id / RST_NR_PER_BANK],
				  BIT(id % RST_NR_PER_BANK), val);
}

static int mtk_reset_assert(struct reset_controller_dev *rcdev,
			    unsigned long id)
{
	return mtk_reset_update(rcdev, id, false);
}

static int mtk_reset_deassert(struct reset_controller_dev *rcdev,
			      unsigned long id)
{
	return mtk_reset_update(rcdev, id, true);
}

static int mtk_reset(struct reset_controller_dev *rcdev, unsigned long id)
{
	int ret;

	ret = mtk_reset_assert(rcdev, id);
	if (ret)
		return ret;

	return mtk_reset_deassert(rcdev, id);
}

static int mtk_reset_update_set_clr(struct reset_controller_dev *rcdev,
				    unsigned long id, bool deassert)
{
	struct mtk_clk_rst_data *data = to_mtk_clk_rst_data(rcdev);
	unsigned int deassert_ofs = deassert ? 0x4 : 0;

	return regmap_write(data->regmap,
			    data->desc->rst_bank_ofs[id / RST_NR_PER_BANK] +
			    deassert_ofs,
			    BIT(id % RST_NR_PER_BANK));
}

static int mtk_reset_assert_set_clr(struct reset_controller_dev *rcdev,
				    unsigned long id)
{
	return mtk_reset_update_set_clr(rcdev, id, false);
}

static int mtk_reset_deassert_set_clr(struct reset_controller_dev *rcdev,
				      unsigned long id)
{
	return mtk_reset_update_set_clr(rcdev, id, true);
}

static int mtk_reset_set_clr(struct reset_controller_dev *rcdev,
			     unsigned long id)
{
	int ret;

	ret = mtk_reset_assert_set_clr(rcdev, id);
	if (ret)
		return ret;
	return mtk_reset_deassert_set_clr(rcdev, id);
}

static const struct reset_control_ops mtk_reset_ops = {
	.assert = mtk_reset_assert,

Annotation

Implementation Notes