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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sun6i_drc.c (3091B)

      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 * Copyright (C) 2016 Free Electrons
      4 *
      5 * Maxime Ripard <maxime.ripard@free-electrons.com>
      6 */
      7
      8#include <linux/clk.h>
      9#include <linux/component.h>
     10#include <linux/module.h>
     11#include <linux/mod_devicetable.h>
     12#include <linux/platform_device.h>
     13#include <linux/regmap.h>
     14#include <linux/reset.h>
     15
     16struct sun6i_drc {
     17	struct clk		*bus_clk;
     18	struct clk		*mod_clk;
     19	struct reset_control	*reset;
     20};
     21
     22static int sun6i_drc_bind(struct device *dev, struct device *master,
     23			 void *data)
     24{
     25	struct sun6i_drc *drc;
     26	int ret;
     27
     28	drc = devm_kzalloc(dev, sizeof(*drc), GFP_KERNEL);
     29	if (!drc)
     30		return -ENOMEM;
     31	dev_set_drvdata(dev, drc);
     32
     33	drc->reset = devm_reset_control_get(dev, NULL);
     34	if (IS_ERR(drc->reset)) {
     35		dev_err(dev, "Couldn't get our reset line\n");
     36		return PTR_ERR(drc->reset);
     37	}
     38
     39	ret = reset_control_deassert(drc->reset);
     40	if (ret) {
     41		dev_err(dev, "Couldn't deassert our reset line\n");
     42		return ret;
     43	}
     44
     45	drc->bus_clk = devm_clk_get(dev, "ahb");
     46	if (IS_ERR(drc->bus_clk)) {
     47		dev_err(dev, "Couldn't get our bus clock\n");
     48		ret = PTR_ERR(drc->bus_clk);
     49		goto err_assert_reset;
     50	}
     51	clk_prepare_enable(drc->bus_clk);
     52
     53	drc->mod_clk = devm_clk_get(dev, "mod");
     54	if (IS_ERR(drc->mod_clk)) {
     55		dev_err(dev, "Couldn't get our mod clock\n");
     56		ret = PTR_ERR(drc->mod_clk);
     57		goto err_disable_bus_clk;
     58	}
     59
     60	ret = clk_set_rate_exclusive(drc->mod_clk, 300000000);
     61	if (ret) {
     62		dev_err(dev, "Couldn't set the module clock frequency\n");
     63		goto err_disable_bus_clk;
     64	}
     65
     66	clk_prepare_enable(drc->mod_clk);
     67
     68	return 0;
     69
     70err_disable_bus_clk:
     71	clk_disable_unprepare(drc->bus_clk);
     72err_assert_reset:
     73	reset_control_assert(drc->reset);
     74	return ret;
     75}
     76
     77static void sun6i_drc_unbind(struct device *dev, struct device *master,
     78			    void *data)
     79{
     80	struct sun6i_drc *drc = dev_get_drvdata(dev);
     81
     82	clk_rate_exclusive_put(drc->mod_clk);
     83	clk_disable_unprepare(drc->mod_clk);
     84	clk_disable_unprepare(drc->bus_clk);
     85	reset_control_assert(drc->reset);
     86}
     87
     88static const struct component_ops sun6i_drc_ops = {
     89	.bind	= sun6i_drc_bind,
     90	.unbind	= sun6i_drc_unbind,
     91};
     92
     93static int sun6i_drc_probe(struct platform_device *pdev)
     94{
     95	return component_add(&pdev->dev, &sun6i_drc_ops);
     96}
     97
     98static int sun6i_drc_remove(struct platform_device *pdev)
     99{
    100	component_del(&pdev->dev, &sun6i_drc_ops);
    101
    102	return 0;
    103}
    104
    105static const struct of_device_id sun6i_drc_of_table[] = {
    106	{ .compatible = "allwinner,sun6i-a31-drc" },
    107	{ .compatible = "allwinner,sun6i-a31s-drc" },
    108	{ .compatible = "allwinner,sun8i-a23-drc" },
    109	{ .compatible = "allwinner,sun8i-a33-drc" },
    110	{ .compatible = "allwinner,sun9i-a80-drc" },
    111	{ }
    112};
    113MODULE_DEVICE_TABLE(of, sun6i_drc_of_table);
    114
    115static struct platform_driver sun6i_drc_platform_driver = {
    116	.probe		= sun6i_drc_probe,
    117	.remove		= sun6i_drc_remove,
    118	.driver		= {
    119		.name		= "sun6i-drc",
    120		.of_match_table	= sun6i_drc_of_table,
    121	},
    122};
    123module_platform_driver(sun6i_drc_platform_driver);
    124
    125MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
    126MODULE_DESCRIPTION("Allwinner A31 Dynamic Range Control (DRC) Driver");
    127MODULE_LICENSE("GPL");