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

/*
 * Copyright (C) 2015 Broadcom
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/clk.h>
#include <linux/clk-provider.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;
	struct resource *res;
	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);

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	reg = devm_ioremap_resource(dev, res);
	if (IS_ERR(reg))
		return PTR_ERR(reg);

	onecell = devm_kmalloc(dev, sizeof(*onecell) + sizeof(*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");
MODULE_LICENSE("GPL v2");