drivers/clk/meson/meson-aoclk.c

Source file repositories/reference/linux-study-clean/drivers/clk/meson/meson-aoclk.c

File Facts

System
Linux kernel
Corpus path
drivers/clk/meson/meson-aoclk.c
Extension
.c
Size
2234 bytes
Lines
89
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+
/*
 * Amlogic Meson-AXG Clock Controller Driver
 *
 * Copyright (c) 2016 BayLibre, SAS.
 * Author: Neil Armstrong <narmstrong@baylibre.com>
 *
 * Copyright (c) 2018 Amlogic, inc.
 * Author: Qiufang Dai <qiufang.dai@amlogic.com>
 * Author: Yixun Lan <yixun.lan@amlogic.com>
 */

#include <linux/platform_device.h>
#include <linux/reset-controller.h>
#include <linux/mfd/syscon.h>
#include <linux/of.h>
#include <linux/module.h>

#include <linux/slab.h>
#include "meson-aoclk.h"
#include "clk-regmap.h"

static int meson_aoclk_do_reset(struct reset_controller_dev *rcdev,
			       unsigned long id)
{
	struct meson_aoclk_reset_controller *rstc =
		container_of(rcdev, struct meson_aoclk_reset_controller, reset);

	return regmap_write(rstc->regmap, rstc->data->reset_reg,
			    BIT(rstc->data->reset[id]));
}

static const struct reset_control_ops meson_aoclk_reset_ops = {
	.reset = meson_aoclk_do_reset,
};

int meson_aoclkc_probe(struct platform_device *pdev)
{
	struct meson_aoclk_reset_controller *rstc;
	const struct meson_clkc_data *clkc_data;
	const struct meson_aoclk_data *data;
	struct device *dev = &pdev->dev;
	struct device_node *np;
	struct regmap *regmap;
	int ret;

	clkc_data = of_device_get_match_data(dev);
	if (!clkc_data)
		return -EINVAL;

	ret = meson_clkc_syscon_probe(pdev);
	if (ret)
		return ret;

	data = container_of(clkc_data, struct meson_aoclk_data,
			    clkc_data);

	rstc = devm_kzalloc(dev, sizeof(*rstc), GFP_KERNEL);
	if (!rstc)
		return -ENOMEM;

	np = of_get_parent(dev->of_node);
	regmap = syscon_node_to_regmap(np);
	of_node_put(np);
	if (IS_ERR(regmap)) {
		dev_err(dev, "failed to get regmap\n");
		return PTR_ERR(regmap);
	}

	/* Reset Controller */
	rstc->data = data;
	rstc->regmap = regmap;
	rstc->reset.ops = &meson_aoclk_reset_ops;
	rstc->reset.nr_resets = data->num_reset;
	rstc->reset.of_node = dev->of_node;
	ret = devm_reset_controller_register(dev, &rstc->reset);
	if (ret) {
		dev_err(dev, "failed to register reset controller\n");
		return ret;
	}

	return 0;
}
EXPORT_SYMBOL_NS_GPL(meson_aoclkc_probe, "CLK_MESON");

MODULE_DESCRIPTION("Amlogic Always-ON Clock Controller helpers");
MODULE_LICENSE("GPL");
MODULE_IMPORT_NS("CLK_MESON");

Annotation

Implementation Notes