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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clk-sun6i-ar100.c (2202B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * Copyright (C) 2014 Free Electrons
      4 *
      5 * Author: Boris BREZILLON <boris.brezillon@free-electrons.com>
      6 *
      7 * Allwinner A31 AR100 clock driver
      8 */
      9
     10#include <linux/bitops.h>
     11#include <linux/clk-provider.h>
     12#include <linux/init.h>
     13#include <linux/of.h>
     14#include <linux/platform_device.h>
     15#include <linux/spinlock.h>
     16
     17#include "clk-factors.h"
     18
     19/*
     20 * sun6i_get_ar100_factors - Calculates factors p, m for AR100
     21 *
     22 * AR100 rate is calculated as follows
     23 * rate = (parent_rate >> p) / (m + 1);
     24 */
     25static void sun6i_get_ar100_factors(struct factors_request *req)
     26{
     27	unsigned long div;
     28	int shift;
     29
     30	/* clock only divides */
     31	if (req->rate > req->parent_rate)
     32		req->rate = req->parent_rate;
     33
     34	div = DIV_ROUND_UP(req->parent_rate, req->rate);
     35
     36	if (div < 32)
     37		shift = 0;
     38	else if (div >> 1 < 32)
     39		shift = 1;
     40	else if (div >> 2 < 32)
     41		shift = 2;
     42	else
     43		shift = 3;
     44
     45	div >>= shift;
     46
     47	if (div > 32)
     48		div = 32;
     49
     50	req->rate = (req->parent_rate >> shift) / div;
     51	req->m = div - 1;
     52	req->p = shift;
     53}
     54
     55static const struct clk_factors_config sun6i_ar100_config = {
     56	.mwidth = 5,
     57	.mshift = 8,
     58	.pwidth = 2,
     59	.pshift = 4,
     60};
     61
     62static const struct factors_data sun6i_ar100_data = {
     63	.mux = 16,
     64	.muxmask = GENMASK(1, 0),
     65	.table = &sun6i_ar100_config,
     66	.getter = sun6i_get_ar100_factors,
     67};
     68
     69static DEFINE_SPINLOCK(sun6i_ar100_lock);
     70
     71static int sun6i_a31_ar100_clk_probe(struct platform_device *pdev)
     72{
     73	struct device_node *np = pdev->dev.of_node;
     74	void __iomem *reg;
     75	struct clk *clk;
     76
     77	reg = devm_platform_ioremap_resource(pdev, 0);
     78	if (IS_ERR(reg))
     79		return PTR_ERR(reg);
     80
     81	clk = sunxi_factors_register(np, &sun6i_ar100_data, &sun6i_ar100_lock,
     82				     reg);
     83	if (!clk)
     84		return -ENOMEM;
     85
     86	platform_set_drvdata(pdev, clk);
     87
     88	return 0;
     89}
     90
     91static const struct of_device_id sun6i_a31_ar100_clk_dt_ids[] = {
     92	{ .compatible = "allwinner,sun6i-a31-ar100-clk" },
     93	{ /* sentinel */ }
     94};
     95
     96static struct platform_driver sun6i_a31_ar100_clk_driver = {
     97	.driver = {
     98		.name = "sun6i-a31-ar100-clk",
     99		.of_match_table = sun6i_a31_ar100_clk_dt_ids,
    100		.suppress_bind_attrs = true,
    101	},
    102	.probe = sun6i_a31_ar100_clk_probe,
    103};
    104builtin_platform_driver(sun6i_a31_ar100_clk_driver);