drivers/clk/bcm/clk-bcm2835-aux.c

Source file repositories/reference/linux-study-clean/drivers/clk/bcm/clk-bcm2835-aux.c

File Facts

System
Linux kernel
Corpus path
drivers/clk/bcm/clk-bcm2835-aux.c
Extension
.c
Size
1928 bytes
Lines
72
Domain
Driver Families
Bucket
drivers/clk
Inferred role
Driver Families: implementation source
Status
source 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+
/*
 * Copyright (C) 2015 Broadcom
 */

#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <dt-bindings/clock/bcm2835-aux.h>

#define BCM2835_AUXIRQ		0x00
#define BCM2835_AUXENB		0x04

static int bcm2835_aux_clk_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct clk_hw_onecell_data *onecell;
	const char *parent;
	struct clk *parent_clk;
	void __iomem *reg, *gate;

	parent_clk = devm_clk_get(dev, NULL);
	if (IS_ERR(parent_clk))
		return PTR_ERR(parent_clk);
	parent = __clk_get_name(parent_clk);

	reg = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(reg))
		return PTR_ERR(reg);

	onecell = devm_kmalloc(dev,
			       struct_size(onecell, hws,
					   BCM2835_AUX_CLOCK_COUNT),
			       GFP_KERNEL);
	if (!onecell)
		return -ENOMEM;
	onecell->num = BCM2835_AUX_CLOCK_COUNT;

	gate = reg + BCM2835_AUXENB;
	onecell->hws[BCM2835_AUX_CLOCK_UART] =
		clk_hw_register_gate(dev, "aux_uart", parent, 0, gate, 0, 0, NULL);

	onecell->hws[BCM2835_AUX_CLOCK_SPI1] =
		clk_hw_register_gate(dev, "aux_spi1", parent, 0, gate, 1, 0, NULL);

	onecell->hws[BCM2835_AUX_CLOCK_SPI2] =
		clk_hw_register_gate(dev, "aux_spi2", parent, 0, gate, 2, 0, NULL);

	return of_clk_add_hw_provider(pdev->dev.of_node, of_clk_hw_onecell_get,
				      onecell);
}

static const struct of_device_id bcm2835_aux_clk_of_match[] = {
	{ .compatible = "brcm,bcm2835-aux", },
	{},
};
MODULE_DEVICE_TABLE(of, bcm2835_aux_clk_of_match);

static struct platform_driver bcm2835_aux_clk_driver = {
	.driver = {
		.name = "bcm2835-aux-clk",
		.of_match_table = bcm2835_aux_clk_of_match,
	},
	.probe          = bcm2835_aux_clk_probe,
};
builtin_platform_driver(bcm2835_aux_clk_driver);

MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
MODULE_DESCRIPTION("BCM2835 auxiliary peripheral clock driver");

Annotation

Implementation Notes