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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apcs-msm8916.c (3673B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * Qualcomm APCS clock controller driver
      4 *
      5 * Copyright (c) 2017, Linaro Limited
      6 * Author: Georgi Djakov <georgi.djakov@linaro.org>
      7 */
      8
      9#include <linux/clk.h>
     10#include <linux/clk-provider.h>
     11#include <linux/kernel.h>
     12#include <linux/module.h>
     13#include <linux/slab.h>
     14#include <linux/platform_device.h>
     15#include <linux/regmap.h>
     16
     17#include "clk-regmap.h"
     18#include "clk-regmap-mux-div.h"
     19
     20static const u32 gpll0_a53cc_map[] = { 4, 5 };
     21
     22static const struct clk_parent_data pdata[] = {
     23	{ .fw_name = "aux", .name = "gpll0_vote", },
     24	{ .fw_name = "pll", .name = "a53pll", },
     25};
     26
     27/*
     28 * We use the notifier function for switching to a temporary safe configuration
     29 * (mux and divider), while the A53 PLL is reconfigured.
     30 */
     31static int a53cc_notifier_cb(struct notifier_block *nb, unsigned long event,
     32			     void *data)
     33{
     34	int ret = 0;
     35	struct clk_regmap_mux_div *md = container_of(nb,
     36						     struct clk_regmap_mux_div,
     37						     clk_nb);
     38	if (event == PRE_RATE_CHANGE)
     39		/* set the mux and divider to safe frequency (400mhz) */
     40		ret = mux_div_set_src_div(md, 4, 3);
     41
     42	return notifier_from_errno(ret);
     43}
     44
     45static int qcom_apcs_msm8916_clk_probe(struct platform_device *pdev)
     46{
     47	struct device *dev = &pdev->dev;
     48	struct device *parent = dev->parent;
     49	struct device_node *np = parent->of_node;
     50	struct clk_regmap_mux_div *a53cc;
     51	struct regmap *regmap;
     52	struct clk_init_data init = { };
     53	int ret = -ENODEV;
     54
     55	regmap = dev_get_regmap(parent, NULL);
     56	if (!regmap) {
     57		dev_err(dev, "failed to get regmap: %d\n", ret);
     58		return ret;
     59	}
     60
     61	a53cc = devm_kzalloc(dev, sizeof(*a53cc), GFP_KERNEL);
     62	if (!a53cc)
     63		return -ENOMEM;
     64
     65	/* Use an unique name by appending parent's @unit-address */
     66	init.name = devm_kasprintf(dev, GFP_KERNEL, "a53mux%s",
     67				   strchrnul(np->full_name, '@'));
     68	if (!init.name)
     69		return -ENOMEM;
     70
     71	init.parent_data = pdata;
     72	init.num_parents = ARRAY_SIZE(pdata);
     73	init.ops = &clk_regmap_mux_div_ops;
     74	init.flags = CLK_IS_CRITICAL | CLK_SET_RATE_PARENT;
     75
     76	a53cc->clkr.hw.init = &init;
     77	a53cc->clkr.regmap = regmap;
     78	a53cc->reg_offset = 0x50;
     79	a53cc->hid_width = 5;
     80	a53cc->hid_shift = 0;
     81	a53cc->src_width = 3;
     82	a53cc->src_shift = 8;
     83	a53cc->parent_map = gpll0_a53cc_map;
     84
     85	a53cc->pclk = devm_clk_get(parent, NULL);
     86	if (IS_ERR(a53cc->pclk)) {
     87		ret = PTR_ERR(a53cc->pclk);
     88		if (ret != -EPROBE_DEFER)
     89			dev_err(dev, "failed to get clk: %d\n", ret);
     90		return ret;
     91	}
     92
     93	a53cc->clk_nb.notifier_call = a53cc_notifier_cb;
     94	ret = clk_notifier_register(a53cc->pclk, &a53cc->clk_nb);
     95	if (ret) {
     96		dev_err(dev, "failed to register clock notifier: %d\n", ret);
     97		return ret;
     98	}
     99
    100	ret = devm_clk_register_regmap(dev, &a53cc->clkr);
    101	if (ret) {
    102		dev_err(dev, "failed to register regmap clock: %d\n", ret);
    103		goto err;
    104	}
    105
    106	ret = devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get,
    107					  &a53cc->clkr.hw);
    108	if (ret) {
    109		dev_err(dev, "failed to add clock provider: %d\n", ret);
    110		goto err;
    111	}
    112
    113	platform_set_drvdata(pdev, a53cc);
    114
    115	return 0;
    116
    117err:
    118	clk_notifier_unregister(a53cc->pclk, &a53cc->clk_nb);
    119	return ret;
    120}
    121
    122static int qcom_apcs_msm8916_clk_remove(struct platform_device *pdev)
    123{
    124	struct clk_regmap_mux_div *a53cc = platform_get_drvdata(pdev);
    125
    126	clk_notifier_unregister(a53cc->pclk, &a53cc->clk_nb);
    127
    128	return 0;
    129}
    130
    131static struct platform_driver qcom_apcs_msm8916_clk_driver = {
    132	.probe = qcom_apcs_msm8916_clk_probe,
    133	.remove = qcom_apcs_msm8916_clk_remove,
    134	.driver = {
    135		.name = "qcom-apcs-msm8916-clk",
    136	},
    137};
    138module_platform_driver(qcom_apcs_msm8916_clk_driver);
    139
    140MODULE_AUTHOR("Georgi Djakov <georgi.djakov@linaro.org>");
    141MODULE_LICENSE("GPL v2");
    142MODULE_DESCRIPTION("Qualcomm MSM8916 APCS clock driver");