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-vexpress-osc.c (2805B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 *
      4 * Copyright (C) 2012 ARM Limited
      5 */
      6
      7#include <linux/clkdev.h>
      8#include <linux/clk-provider.h>
      9#include <linux/err.h>
     10#include <linux/module.h>
     11#include <linux/of.h>
     12#include <linux/platform_device.h>
     13#include <linux/slab.h>
     14#include <linux/vexpress.h>
     15
     16struct vexpress_osc {
     17	struct regmap *reg;
     18	struct clk_hw hw;
     19	unsigned long rate_min;
     20	unsigned long rate_max;
     21};
     22
     23#define to_vexpress_osc(osc) container_of(osc, struct vexpress_osc, hw)
     24
     25static unsigned long vexpress_osc_recalc_rate(struct clk_hw *hw,
     26		unsigned long parent_rate)
     27{
     28	struct vexpress_osc *osc = to_vexpress_osc(hw);
     29	u32 rate;
     30
     31	regmap_read(osc->reg, 0, &rate);
     32
     33	return rate;
     34}
     35
     36static long vexpress_osc_round_rate(struct clk_hw *hw, unsigned long rate,
     37		unsigned long *parent_rate)
     38{
     39	struct vexpress_osc *osc = to_vexpress_osc(hw);
     40
     41	if (osc->rate_min && rate < osc->rate_min)
     42		rate = osc->rate_min;
     43
     44	if (osc->rate_max && rate > osc->rate_max)
     45		rate = osc->rate_max;
     46
     47	return rate;
     48}
     49
     50static int vexpress_osc_set_rate(struct clk_hw *hw, unsigned long rate,
     51		unsigned long parent_rate)
     52{
     53	struct vexpress_osc *osc = to_vexpress_osc(hw);
     54
     55	return regmap_write(osc->reg, 0, rate);
     56}
     57
     58static const struct clk_ops vexpress_osc_ops = {
     59	.recalc_rate = vexpress_osc_recalc_rate,
     60	.round_rate = vexpress_osc_round_rate,
     61	.set_rate = vexpress_osc_set_rate,
     62};
     63
     64
     65static int vexpress_osc_probe(struct platform_device *pdev)
     66{
     67	struct clk_init_data init;
     68	struct vexpress_osc *osc;
     69	u32 range[2];
     70	int ret;
     71
     72	osc = devm_kzalloc(&pdev->dev, sizeof(*osc), GFP_KERNEL);
     73	if (!osc)
     74		return -ENOMEM;
     75
     76	osc->reg = devm_regmap_init_vexpress_config(&pdev->dev);
     77	if (IS_ERR(osc->reg))
     78		return PTR_ERR(osc->reg);
     79
     80	if (of_property_read_u32_array(pdev->dev.of_node, "freq-range", range,
     81			ARRAY_SIZE(range)) == 0) {
     82		osc->rate_min = range[0];
     83		osc->rate_max = range[1];
     84	}
     85
     86	if (of_property_read_string(pdev->dev.of_node, "clock-output-names",
     87			&init.name) != 0)
     88		init.name = dev_name(&pdev->dev);
     89
     90	init.ops = &vexpress_osc_ops;
     91	init.flags = 0;
     92	init.num_parents = 0;
     93
     94	osc->hw.init = &init;
     95
     96	ret = devm_clk_hw_register(&pdev->dev, &osc->hw);
     97	if (ret < 0)
     98		return ret;
     99
    100	devm_of_clk_add_hw_provider(&pdev->dev, of_clk_hw_simple_get, &osc->hw);
    101	clk_hw_set_rate_range(&osc->hw, osc->rate_min, osc->rate_max);
    102
    103	dev_dbg(&pdev->dev, "Registered clock '%s'\n", init.name);
    104
    105	return 0;
    106}
    107
    108static const struct of_device_id vexpress_osc_of_match[] = {
    109	{ .compatible = "arm,vexpress-osc", },
    110	{}
    111};
    112MODULE_DEVICE_TABLE(of, vexpress_osc_of_match);
    113
    114static struct platform_driver vexpress_osc_driver = {
    115	.driver	= {
    116		.name = "vexpress-osc",
    117		.of_match_table = vexpress_osc_of_match,
    118	},
    119	.probe = vexpress_osc_probe,
    120};
    121module_platform_driver(vexpress_osc_driver);
    122MODULE_LICENSE("GPL v2");