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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irq-ts4800.c (4091B)

      1/*
      2 * Multiplexed-IRQs driver for TS-4800's FPGA
      3 *
      4 * Copyright (c) 2015 - Savoir-faire Linux
      5 *
      6 * This file is licensed under the terms of the GNU General Public
      7 * License version 2. This program is licensed "as is" without any
      8 * warranty of any kind, whether express or implied.
      9 */
     10
     11#include <linux/interrupt.h>
     12#include <linux/io.h>
     13#include <linux/irq.h>
     14#include <linux/irqchip.h>
     15#include <linux/irqchip/chained_irq.h>
     16#include <linux/irqdomain.h>
     17#include <linux/module.h>
     18#include <linux/of.h>
     19#include <linux/of_address.h>
     20#include <linux/of_irq.h>
     21#include <linux/platform_device.h>
     22#include <linux/seq_file.h>
     23
     24#define IRQ_MASK        0x4
     25#define IRQ_STATUS      0x8
     26
     27struct ts4800_irq_data {
     28	void __iomem            *base;
     29	struct platform_device	*pdev;
     30	struct irq_domain       *domain;
     31};
     32
     33static void ts4800_irq_mask(struct irq_data *d)
     34{
     35	struct ts4800_irq_data *data = irq_data_get_irq_chip_data(d);
     36	u16 reg = readw(data->base + IRQ_MASK);
     37	u16 mask = 1 << d->hwirq;
     38
     39	writew(reg | mask, data->base + IRQ_MASK);
     40}
     41
     42static void ts4800_irq_unmask(struct irq_data *d)
     43{
     44	struct ts4800_irq_data *data = irq_data_get_irq_chip_data(d);
     45	u16 reg = readw(data->base + IRQ_MASK);
     46	u16 mask = 1 << d->hwirq;
     47
     48	writew(reg & ~mask, data->base + IRQ_MASK);
     49}
     50
     51static void ts4800_irq_print_chip(struct irq_data *d, struct seq_file *p)
     52{
     53	struct ts4800_irq_data *data = irq_data_get_irq_chip_data(d);
     54
     55	seq_printf(p, "%s", dev_name(&data->pdev->dev));
     56}
     57
     58static const struct irq_chip ts4800_chip = {
     59	.irq_mask	= ts4800_irq_mask,
     60	.irq_unmask	= ts4800_irq_unmask,
     61	.irq_print_chip	= ts4800_irq_print_chip,
     62};
     63
     64static int ts4800_irqdomain_map(struct irq_domain *d, unsigned int irq,
     65				irq_hw_number_t hwirq)
     66{
     67	struct ts4800_irq_data *data = d->host_data;
     68
     69	irq_set_chip_and_handler(irq, &ts4800_chip, handle_simple_irq);
     70	irq_set_chip_data(irq, data);
     71	irq_set_noprobe(irq);
     72
     73	return 0;
     74}
     75
     76static const struct irq_domain_ops ts4800_ic_ops = {
     77	.map = ts4800_irqdomain_map,
     78	.xlate = irq_domain_xlate_onecell,
     79};
     80
     81static void ts4800_ic_chained_handle_irq(struct irq_desc *desc)
     82{
     83	struct ts4800_irq_data *data = irq_desc_get_handler_data(desc);
     84	struct irq_chip *chip = irq_desc_get_chip(desc);
     85	u16 status = readw(data->base + IRQ_STATUS);
     86
     87	chained_irq_enter(chip, desc);
     88
     89	if (unlikely(status == 0)) {
     90		handle_bad_irq(desc);
     91		goto out;
     92	}
     93
     94	do {
     95		unsigned int bit = __ffs(status);
     96
     97		generic_handle_domain_irq(data->domain, bit);
     98		status &= ~(1 << bit);
     99	} while (status);
    100
    101out:
    102	chained_irq_exit(chip, desc);
    103}
    104
    105static int ts4800_ic_probe(struct platform_device *pdev)
    106{
    107	struct device_node *node = pdev->dev.of_node;
    108	struct ts4800_irq_data *data;
    109	int parent_irq;
    110
    111	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
    112	if (!data)
    113		return -ENOMEM;
    114
    115	data->pdev = pdev;
    116	data->base = devm_platform_ioremap_resource(pdev, 0);
    117	if (IS_ERR(data->base))
    118		return PTR_ERR(data->base);
    119
    120	writew(0xFFFF, data->base + IRQ_MASK);
    121
    122	parent_irq = irq_of_parse_and_map(node, 0);
    123	if (!parent_irq) {
    124		dev_err(&pdev->dev, "failed to get parent IRQ\n");
    125		return -EINVAL;
    126	}
    127
    128	data->domain = irq_domain_add_linear(node, 8, &ts4800_ic_ops, data);
    129	if (!data->domain) {
    130		dev_err(&pdev->dev, "cannot add IRQ domain\n");
    131		return -ENOMEM;
    132	}
    133
    134	irq_set_chained_handler_and_data(parent_irq,
    135					 ts4800_ic_chained_handle_irq, data);
    136
    137	platform_set_drvdata(pdev, data);
    138
    139	return 0;
    140}
    141
    142static int ts4800_ic_remove(struct platform_device *pdev)
    143{
    144	struct ts4800_irq_data *data = platform_get_drvdata(pdev);
    145
    146	irq_domain_remove(data->domain);
    147
    148	return 0;
    149}
    150
    151static const struct of_device_id ts4800_ic_of_match[] = {
    152	{ .compatible = "technologic,ts4800-irqc", },
    153	{},
    154};
    155MODULE_DEVICE_TABLE(of, ts4800_ic_of_match);
    156
    157static struct platform_driver ts4800_ic_driver = {
    158	.probe  = ts4800_ic_probe,
    159	.remove = ts4800_ic_remove,
    160	.driver = {
    161		.name = "ts4800-irqc",
    162		.of_match_table = ts4800_ic_of_match,
    163	},
    164};
    165module_platform_driver(ts4800_ic_driver);
    166
    167MODULE_AUTHOR("Damien Riegel <damien.riegel@savoirfairelinux.com>");
    168MODULE_LICENSE("GPL v2");
    169MODULE_ALIAS("platform:ts4800_irqc");