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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armada-37xx-xtal.c (2065B)


      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * Marvell Armada 37xx SoC xtal clocks
      4 *
      5 * Copyright (C) 2016 Marvell
      6 *
      7 * Gregory CLEMENT <gregory.clement@free-electrons.com>
      8 *
      9 */
     10
     11#include <linux/clk-provider.h>
     12#include <linux/mfd/syscon.h>
     13#include <linux/platform_device.h>
     14#include <linux/regmap.h>
     15
     16#define NB_GPIO1_LATCH	0x8
     17#define XTAL_MODE	    BIT(9)
     18
     19static int armada_3700_xtal_clock_probe(struct platform_device *pdev)
     20{
     21	struct device_node *np = pdev->dev.of_node;
     22	const char *xtal_name = "xtal";
     23	struct device_node *parent;
     24	struct regmap *regmap;
     25	struct clk_hw *xtal_hw;
     26	unsigned int rate;
     27	u32 reg;
     28	int ret;
     29
     30	xtal_hw = devm_kzalloc(&pdev->dev, sizeof(*xtal_hw), GFP_KERNEL);
     31	if (!xtal_hw)
     32		return -ENOMEM;
     33
     34	platform_set_drvdata(pdev, xtal_hw);
     35
     36	parent = np->parent;
     37	if (!parent) {
     38		dev_err(&pdev->dev, "no parent\n");
     39		return -ENODEV;
     40	}
     41
     42	regmap = syscon_node_to_regmap(parent);
     43	if (IS_ERR(regmap)) {
     44		dev_err(&pdev->dev, "cannot get regmap\n");
     45		return PTR_ERR(regmap);
     46	}
     47
     48	ret = regmap_read(regmap, NB_GPIO1_LATCH, &reg);
     49	if (ret) {
     50		dev_err(&pdev->dev, "cannot read from regmap\n");
     51		return ret;
     52	}
     53
     54	if (reg & XTAL_MODE)
     55		rate = 40000000;
     56	else
     57		rate = 25000000;
     58
     59	of_property_read_string_index(np, "clock-output-names", 0, &xtal_name);
     60	xtal_hw = clk_hw_register_fixed_rate(NULL, xtal_name, NULL, 0, rate);
     61	if (IS_ERR(xtal_hw))
     62		return PTR_ERR(xtal_hw);
     63	ret = of_clk_add_hw_provider(np, of_clk_hw_simple_get, xtal_hw);
     64
     65	return ret;
     66}
     67
     68static int armada_3700_xtal_clock_remove(struct platform_device *pdev)
     69{
     70	of_clk_del_provider(pdev->dev.of_node);
     71
     72	return 0;
     73}
     74
     75static const struct of_device_id armada_3700_xtal_clock_of_match[] = {
     76	{ .compatible = "marvell,armada-3700-xtal-clock", },
     77	{ }
     78};
     79
     80static struct platform_driver armada_3700_xtal_clock_driver = {
     81	.probe = armada_3700_xtal_clock_probe,
     82	.remove = armada_3700_xtal_clock_remove,
     83	.driver		= {
     84		.name	= "marvell-armada-3700-xtal-clock",
     85		.of_match_table = armada_3700_xtal_clock_of_match,
     86	},
     87};
     88
     89builtin_platform_driver(armada_3700_xtal_clock_driver);