linux_kernel/drivers/bus/tegra-aconnect.c

/*
 * Tegra ACONNECT Bus Driver
 *
 * Copyright (C) 2016, NVIDIA CORPORATION.  All rights reserved.
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 */

#include <linux/clk.h>
#include <linux/module.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/pm_clock.h>
#include <linux/pm_runtime.h>

static int tegra_aconnect_add_clock(struct device *dev, char *name)
{
	struct clk *clk;
	int ret;

	clk = clk_get(dev, name);
	if (IS_ERR(clk)) {
		dev_err(dev, "%s clock not found\n", name);
		return PTR_ERR(clk);
	}

	ret = pm_clk_add_clk(dev, clk);
	if (ret)
		clk_put(clk);

	return ret;
}

static int tegra_aconnect_probe(struct platform_device *pdev)
{
	int ret;

	if (!pdev->dev.of_node)
		return -EINVAL;

	ret = pm_clk_create(&pdev->dev);
	if (ret)
		return ret;

	ret = tegra_aconnect_add_clock(&pdev->dev, "ape");
	if (ret)
		goto clk_destroy;

	ret = tegra_aconnect_add_clock(&pdev->dev, "apb2ape");
	if (ret)
		goto clk_destroy;

	pm_runtime_enable(&pdev->dev);

	of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev);

	dev_info(&pdev->dev, "Tegra ACONNECT bus registered\n");

	return 0;

clk_destroy:
	pm_clk_destroy(&pdev->dev);

	return ret;
}

static int tegra_aconnect_remove(struct platform_device *pdev)
{
	pm_runtime_disable(&pdev->dev);

	pm_clk_destroy(&pdev->dev);

	return 0;
}

static int tegra_aconnect_runtime_resume(struct device *dev)
{
	return pm_clk_resume(dev);
}

static int tegra_aconnect_runtime_suspend(struct device *dev)
{
	return pm_clk_suspend(dev);
}

static const struct dev_pm_ops tegra_aconnect_pm_ops = {
	SET_RUNTIME_PM_OPS(tegra_aconnect_runtime_suspend,
			   tegra_aconnect_runtime_resume, NULL)
};

static const struct of_device_id tegra_aconnect_of_match[] = {
	{ .compatible = "nvidia,tegra210-aconnect", },
	{ }
};
MODULE_DEVICE_TABLE(of, tegra_aconnect_of_match);

static struct platform_driver tegra_aconnect_driver = {
	.probe = tegra_aconnect_probe,
	.remove = tegra_aconnect_remove,
	.driver = {
		.name = "tegra-aconnect",
		.of_match_table = tegra_aconnect_of_match,
		.pm = &tegra_aconnect_pm_ops,
	},
};
module_platform_driver(tegra_aconnect_driver);

MODULE_DESCRIPTION("NVIDIA Tegra ACONNECT Bus Driver");
MODULE_AUTHOR("Jon Hunter <jonathanh@nvidia.com>");
MODULE_LICENSE("GPL v2");