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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arm-integrator-lm.c (3204B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * ARM Integrator Logical Module bus driver
      4 * Copyright (C) 2020 Linaro Ltd.
      5 * Author: Linus Walleij <linus.walleij@linaro.org>
      6 *
      7 * See the device tree bindings for this block for more details on the
      8 * hardware.
      9 */
     10
     11#include <linux/module.h>
     12#include <linux/err.h>
     13#include <linux/io.h>
     14#include <linux/of.h>
     15#include <linux/of_address.h>
     16#include <linux/of_platform.h>
     17#include <linux/init.h>
     18#include <linux/slab.h>
     19#include <linux/platform_device.h>
     20#include <linux/bitops.h>
     21#include <linux/mfd/syscon.h>
     22#include <linux/regmap.h>
     23
     24/* All information about the connected logic modules are in here */
     25#define INTEGRATOR_SC_DEC_OFFSET	0x10
     26
     27/* Base address for the expansion modules */
     28#define INTEGRATOR_AP_EXP_BASE		0xc0000000
     29#define INTEGRATOR_AP_EXP_STRIDE	0x10000000
     30
     31static int integrator_lm_populate(int num, struct device *dev)
     32{
     33	struct device_node *np = dev->of_node;
     34	struct device_node *child;
     35	u32 base;
     36	int ret;
     37
     38	base = INTEGRATOR_AP_EXP_BASE + (num * INTEGRATOR_AP_EXP_STRIDE);
     39
     40	/* Walk over the child nodes and see what chipselects we use */
     41	for_each_available_child_of_node(np, child) {
     42		struct resource res;
     43
     44		ret = of_address_to_resource(child, 0, &res);
     45		if (ret) {
     46			dev_info(dev, "no valid address on child\n");
     47			continue;
     48		}
     49
     50		/* First populate the syscon then any devices */
     51		if (res.start == base) {
     52			dev_info(dev, "populate module @0x%08x from DT\n",
     53				 base);
     54			ret = of_platform_default_populate(child, NULL, dev);
     55			if (ret) {
     56				dev_err(dev, "failed to populate module\n");
     57				of_node_put(child);
     58				return ret;
     59			}
     60		}
     61	}
     62
     63	return 0;
     64}
     65
     66static const struct of_device_id integrator_ap_syscon_match[] = {
     67	{ .compatible = "arm,integrator-ap-syscon"},
     68	{ },
     69};
     70
     71static int integrator_ap_lm_probe(struct platform_device *pdev)
     72{
     73	struct device *dev = &pdev->dev;
     74	struct device_node *syscon;
     75	static struct regmap *map;
     76	u32 val;
     77	int ret;
     78	int i;
     79
     80	/* Look up the system controller */
     81	syscon = of_find_matching_node(NULL, integrator_ap_syscon_match);
     82	if (!syscon) {
     83		dev_err(dev,
     84			"could not find Integrator/AP system controller\n");
     85		return -ENODEV;
     86	}
     87	map = syscon_node_to_regmap(syscon);
     88	if (IS_ERR(map)) {
     89		dev_err(dev,
     90			"could not find Integrator/AP system controller\n");
     91		return PTR_ERR(map);
     92	}
     93
     94	ret = regmap_read(map, INTEGRATOR_SC_DEC_OFFSET, &val);
     95	if (ret) {
     96		dev_err(dev, "could not read from Integrator/AP syscon\n");
     97		return ret;
     98	}
     99
    100	/* Loop over the connected modules */
    101	for (i = 0; i < 4; i++) {
    102		if (!(val & BIT(4 + i)))
    103			continue;
    104
    105		dev_info(dev, "detected module in slot %d\n", i);
    106		ret = integrator_lm_populate(i, dev);
    107		if (ret)
    108			return ret;
    109	}
    110
    111	return 0;
    112}
    113
    114static const struct of_device_id integrator_ap_lm_match[] = {
    115	{ .compatible = "arm,integrator-ap-lm"},
    116	{ },
    117};
    118
    119static struct platform_driver integrator_ap_lm_driver = {
    120	.probe = integrator_ap_lm_probe,
    121	.driver = {
    122		.name = "integratorap-lm",
    123		.of_match_table = integrator_ap_lm_match,
    124	},
    125};
    126module_platform_driver(integrator_ap_lm_driver);
    127MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");
    128MODULE_DESCRIPTION("Integrator AP Logical Module driver");
    129MODULE_LICENSE("GPL v2");