cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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simple-pm-bus.c (2749B)

      1/*
      2 * Simple Power-Managed Bus Driver
      3 *
      4 * Copyright (C) 2014-2015 Glider bvba
      5 *
      6 * This file is subject to the terms and conditions of the GNU General Public
      7 * License.  See the file "COPYING" in the main directory of this archive
      8 * for more details.
      9 */
     10
     11#include <linux/module.h>
     12#include <linux/of_platform.h>
     13#include <linux/platform_device.h>
     14#include <linux/pm_runtime.h>
     15
     16static int simple_pm_bus_probe(struct platform_device *pdev)
     17{
     18	const struct device *dev = &pdev->dev;
     19	const struct of_dev_auxdata *lookup = dev_get_platdata(dev);
     20	struct device_node *np = dev->of_node;
     21	const struct of_device_id *match;
     22
     23	/*
     24	 * Allow user to use driver_override to bind this driver to a
     25	 * transparent bus device which has a different compatible string
     26	 * that's not listed in simple_pm_bus_of_match. We don't want to do any
     27	 * of the simple-pm-bus tasks for these devices, so return early.
     28	 */
     29	if (pdev->driver_override)
     30		return 0;
     31
     32	match = of_match_device(dev->driver->of_match_table, dev);
     33	/*
     34	 * These are transparent bus devices (not simple-pm-bus matches) that
     35	 * have their child nodes populated automatically.  So, don't need to
     36	 * do anything more. We only match with the device if this driver is
     37	 * the most specific match because we don't want to incorrectly bind to
     38	 * a device that has a more specific driver.
     39	 */
     40	if (match && match->data) {
     41		if (of_property_match_string(np, "compatible", match->compatible) == 0)
     42			return 0;
     43		else
     44			return -ENODEV;
     45	}
     46
     47	dev_dbg(&pdev->dev, "%s\n", __func__);
     48
     49	pm_runtime_enable(&pdev->dev);
     50
     51	if (np)
     52		of_platform_populate(np, NULL, lookup, &pdev->dev);
     53
     54	return 0;
     55}
     56
     57static int simple_pm_bus_remove(struct platform_device *pdev)
     58{
     59	const void *data = of_device_get_match_data(&pdev->dev);
     60
     61	if (pdev->driver_override || data)
     62		return 0;
     63
     64	dev_dbg(&pdev->dev, "%s\n", __func__);
     65
     66	pm_runtime_disable(&pdev->dev);
     67	return 0;
     68}
     69
     70#define ONLY_BUS	((void *) 1) /* Match if the device is only a bus. */
     71
     72static const struct of_device_id simple_pm_bus_of_match[] = {
     73	{ .compatible = "simple-pm-bus", },
     74	{ .compatible = "simple-bus",	.data = ONLY_BUS },
     75	{ .compatible = "simple-mfd",	.data = ONLY_BUS },
     76	{ .compatible = "isa",		.data = ONLY_BUS },
     77	{ .compatible = "arm,amba-bus",	.data = ONLY_BUS },
     78	{ /* sentinel */ }
     79};
     80MODULE_DEVICE_TABLE(of, simple_pm_bus_of_match);
     81
     82static struct platform_driver simple_pm_bus_driver = {
     83	.probe = simple_pm_bus_probe,
     84	.remove = simple_pm_bus_remove,
     85	.driver = {
     86		.name = "simple-pm-bus",
     87		.of_match_table = simple_pm_bus_of_match,
     88	},
     89};
     90
     91module_platform_driver(simple_pm_bus_driver);
     92
     93MODULE_DESCRIPTION("Simple Power-Managed Bus Driver");
     94MODULE_AUTHOR("Geert Uytterhoeven <geert+renesas@glider.be>");
     95MODULE_LICENSE("GPL v2");