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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reset-brcmstb-rescal.c (2887B)

      1// SPDX-License-Identifier: GPL-2.0
      2/* Copyright (C) 2018-2020 Broadcom */
      3
      4#include <linux/device.h>
      5#include <linux/iopoll.h>
      6#include <linux/module.h>
      7#include <linux/of.h>
      8#include <linux/platform_device.h>
      9#include <linux/reset-controller.h>
     10
     11#define BRCM_RESCAL_START	0x0
     12#define  BRCM_RESCAL_START_BIT	BIT(0)
     13#define BRCM_RESCAL_CTRL	0x4
     14#define BRCM_RESCAL_STATUS	0x8
     15#define  BRCM_RESCAL_STATUS_BIT	BIT(0)
     16
     17struct brcm_rescal_reset {
     18	void __iomem *base;
     19	struct device *dev;
     20	struct reset_controller_dev rcdev;
     21};
     22
     23static int brcm_rescal_reset_set(struct reset_controller_dev *rcdev,
     24				 unsigned long id)
     25{
     26	struct brcm_rescal_reset *data =
     27		container_of(rcdev, struct brcm_rescal_reset, rcdev);
     28	void __iomem *base = data->base;
     29	u32 reg;
     30	int ret;
     31
     32	reg = readl(base + BRCM_RESCAL_START);
     33	writel(reg | BRCM_RESCAL_START_BIT, base + BRCM_RESCAL_START);
     34	reg = readl(base + BRCM_RESCAL_START);
     35	if (!(reg & BRCM_RESCAL_START_BIT)) {
     36		dev_err(data->dev, "failed to start SATA/PCIe rescal\n");
     37		return -EIO;
     38	}
     39
     40	ret = readl_poll_timeout(base + BRCM_RESCAL_STATUS, reg,
     41				 (reg & BRCM_RESCAL_STATUS_BIT), 100, 1000);
     42	if (ret) {
     43		dev_err(data->dev, "time out on SATA/PCIe rescal\n");
     44		return ret;
     45	}
     46
     47	reg = readl(base + BRCM_RESCAL_START);
     48	writel(reg & ~BRCM_RESCAL_START_BIT, base + BRCM_RESCAL_START);
     49
     50	dev_dbg(data->dev, "SATA/PCIe rescal success\n");
     51
     52	return 0;
     53}
     54
     55static int brcm_rescal_reset_xlate(struct reset_controller_dev *rcdev,
     56				   const struct of_phandle_args *reset_spec)
     57{
     58	/* This is needed if #reset-cells == 0. */
     59	return 0;
     60}
     61
     62static const struct reset_control_ops brcm_rescal_reset_ops = {
     63	.reset = brcm_rescal_reset_set,
     64};
     65
     66static int brcm_rescal_reset_probe(struct platform_device *pdev)
     67{
     68	struct brcm_rescal_reset *data;
     69	struct resource *res;
     70
     71	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
     72	if (!data)
     73		return -ENOMEM;
     74
     75	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
     76	data->base = devm_ioremap_resource(&pdev->dev, res);
     77	if (IS_ERR(data->base))
     78		return PTR_ERR(data->base);
     79
     80	data->rcdev.owner = THIS_MODULE;
     81	data->rcdev.nr_resets = 1;
     82	data->rcdev.ops = &brcm_rescal_reset_ops;
     83	data->rcdev.of_node = pdev->dev.of_node;
     84	data->rcdev.of_xlate = brcm_rescal_reset_xlate;
     85	data->dev = &pdev->dev;
     86
     87	return devm_reset_controller_register(&pdev->dev, &data->rcdev);
     88}
     89
     90static const struct of_device_id brcm_rescal_reset_of_match[] = {
     91	{ .compatible = "brcm,bcm7216-pcie-sata-rescal" },
     92	{ },
     93};
     94MODULE_DEVICE_TABLE(of, brcm_rescal_reset_of_match);
     95
     96static struct platform_driver brcm_rescal_reset_driver = {
     97	.probe = brcm_rescal_reset_probe,
     98	.driver = {
     99		.name	= "brcm-rescal-reset",
    100		.of_match_table	= brcm_rescal_reset_of_match,
    101	}
    102};
    103module_platform_driver(brcm_rescal_reset_driver);
    104
    105MODULE_AUTHOR("Broadcom");
    106MODULE_DESCRIPTION("Broadcom SATA/PCIe rescal reset controller");
    107MODULE_LICENSE("GPL v2");