root/drivers/irqchip/irq-renesas-rza1.c
// SPDX-License-Identifier: GPL-2.0
/*
 * Renesas RZ/A1 IRQC Driver
 *
 * Copyright (C) 2019 Glider bvba
 */

#include <linux/err.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/irqdomain.h>
#include <linux/irq.h>
#include <linux/module.h>
#include <linux/of_irq.h>
#include <linux/platform_device.h>
#include <linux/slab.h>

#include <dt-bindings/interrupt-controller/arm-gic.h>

#define IRQC_NUM_IRQ            8

#define ICR0                    0       /* Interrupt Control Register 0 */

#define ICR0_NMIL               BIT(15) /* NMI Input Level (0=low, 1=high) */
#define ICR0_NMIE               BIT(8)  /* Edge Select (0=falling, 1=rising) */
#define ICR0_NMIF               BIT(1)  /* NMI Interrupt Request */

#define ICR1                    2       /* Interrupt Control Register 1 */

#define ICR1_IRQS(n, sense)     ((sense) << ((n) * 2))  /* IRQ Sense Select */
#define ICR1_IRQS_LEVEL_LOW     0
#define ICR1_IRQS_EDGE_FALLING  1
#define ICR1_IRQS_EDGE_RISING   2
#define ICR1_IRQS_EDGE_BOTH     3
#define ICR1_IRQS_MASK(n)       ICR1_IRQS((n), 3)

#define IRQRR                   4       /* IRQ Interrupt Request Register */


struct rza1_irqc_priv {
        struct device *dev;
        void __iomem *base;
        struct irq_chip chip;
        struct irq_domain *irq_domain;
        struct of_phandle_args map[IRQC_NUM_IRQ];
};

static struct rza1_irqc_priv *irq_data_to_priv(struct irq_data *data)
{
        return data->domain->host_data;
}

static void rza1_irqc_eoi(struct irq_data *d)
{
        struct rza1_irqc_priv *priv = irq_data_to_priv(d);
        u16 bit = BIT(irqd_to_hwirq(d));
        u16 tmp;

        tmp = readw_relaxed(priv->base + IRQRR);
        if (tmp & bit)
                writew_relaxed(GENMASK(IRQC_NUM_IRQ - 1, 0) & ~bit,
                               priv->base + IRQRR);

        irq_chip_eoi_parent(d);
}

static int rza1_irqc_set_type(struct irq_data *d, unsigned int type)
{
        struct rza1_irqc_priv *priv = irq_data_to_priv(d);
        unsigned int hw_irq = irqd_to_hwirq(d);
        u16 sense, tmp;

        switch (type & IRQ_TYPE_SENSE_MASK) {
        case IRQ_TYPE_LEVEL_LOW:
                sense = ICR1_IRQS_LEVEL_LOW;
                break;

        case IRQ_TYPE_EDGE_FALLING:
                sense = ICR1_IRQS_EDGE_FALLING;
                break;

        case IRQ_TYPE_EDGE_RISING:
                sense = ICR1_IRQS_EDGE_RISING;
                break;

        case IRQ_TYPE_EDGE_BOTH:
                sense = ICR1_IRQS_EDGE_BOTH;
                break;

        default:
                return -EINVAL;
        }

        tmp = readw_relaxed(priv->base + ICR1);
        tmp &= ~ICR1_IRQS_MASK(hw_irq);
        tmp |= ICR1_IRQS(hw_irq, sense);
        writew_relaxed(tmp, priv->base + ICR1);
        return 0;
}

static int rza1_irqc_alloc(struct irq_domain *domain, unsigned int virq,
                           unsigned int nr_irqs, void *arg)
{
        struct rza1_irqc_priv *priv = domain->host_data;
        struct irq_fwspec *fwspec = arg;
        unsigned int hwirq = fwspec->param[0];
        struct irq_fwspec spec;
        unsigned int i;
        int ret;

        ret = irq_domain_set_hwirq_and_chip(domain, virq, hwirq, &priv->chip,
                                            priv);
        if (ret)
                return ret;

        spec.fwnode = &priv->dev->of_node->fwnode;
        spec.param_count = priv->map[hwirq].args_count;
        for (i = 0; i < spec.param_count; i++)
                spec.param[i] = priv->map[hwirq].args[i];

        return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, &spec);
}

static int rza1_irqc_translate(struct irq_domain *domain,
                               struct irq_fwspec *fwspec, unsigned long *hwirq,
                               unsigned int *type)
{
        if (fwspec->param_count != 2 || fwspec->param[0] >= IRQC_NUM_IRQ)
                return -EINVAL;

        *hwirq = fwspec->param[0];
        *type = fwspec->param[1];
        return 0;
}

static const struct irq_domain_ops rza1_irqc_domain_ops = {
        .alloc = rza1_irqc_alloc,
        .translate = rza1_irqc_translate,
};

static int rza1_irqc_parse_map(struct rza1_irqc_priv *priv,
                               struct device_node *gic_node)
{
        struct of_imap_parser imap_parser;
        struct device *dev = priv->dev;
        struct of_imap_item imap_item;
        struct device_node *ipar;
        unsigned int j;
        u32 i = 0;
        int ret;

        ret = of_imap_parser_init(&imap_parser, dev->of_node, &imap_item);
        if (ret)
                return ret;

        for_each_of_imap_item(&imap_parser, &imap_item) {
                /* Check interrupt number, ignore sense */
                if (imap_item.child_imap[0] != i) {
                        of_node_put(imap_item.parent_args.np);
                        return -EINVAL;
                }

                ipar  = imap_item.parent_args.np;
                if (ipar != gic_node) {
                        of_node_put(ipar);
                        return -EINVAL;
                }

                priv->map[i].args_count = imap_item.parent_args.args_count;
                for (j = 0; j < priv->map[i].args_count; j++)
                        priv->map[i].args[j] = imap_item.parent_args.args[j];

                i++;
        }

        return 0;
}

static int rza1_irqc_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct device_node *np = dev->of_node;
        struct irq_domain *parent = NULL;
        struct device_node *gic_node;
        struct rza1_irqc_priv *priv;
        int ret;

        priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
        if (!priv)
                return -ENOMEM;

        platform_set_drvdata(pdev, priv);
        priv->dev = dev;

        priv->base = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(priv->base))
                return PTR_ERR(priv->base);

        gic_node = of_irq_find_parent(np);
        if (gic_node)
                parent = irq_find_host(gic_node);

        if (!parent) {
                dev_err(dev, "cannot find parent domain\n");
                ret = -ENODEV;
                goto out_put_node;
        }

        ret = rza1_irqc_parse_map(priv, gic_node);
        if (ret) {
                dev_err(dev, "cannot parse %s: %d\n", "interrupt-map", ret);
                goto out_put_node;
        }

        priv->chip.name = "rza1-irqc";
        priv->chip.irq_mask = irq_chip_mask_parent;
        priv->chip.irq_unmask = irq_chip_unmask_parent;
        priv->chip.irq_eoi = rza1_irqc_eoi;
        priv->chip.irq_retrigger = irq_chip_retrigger_hierarchy;
        priv->chip.irq_set_type = rza1_irqc_set_type;
        priv->chip.flags = IRQCHIP_MASK_ON_SUSPEND | IRQCHIP_SKIP_SET_WAKE;

        priv->irq_domain = irq_domain_create_hierarchy(parent, 0, IRQC_NUM_IRQ, dev_fwnode(dev),
                                                       &rza1_irqc_domain_ops, priv);
        if (!priv->irq_domain) {
                dev_err(dev, "cannot initialize irq domain\n");
                ret = -ENOMEM;
        }

out_put_node:
        of_node_put(gic_node);
        return ret;
}

static void rza1_irqc_remove(struct platform_device *pdev)
{
        struct rza1_irqc_priv *priv = platform_get_drvdata(pdev);

        irq_domain_remove(priv->irq_domain);
}

static const struct of_device_id rza1_irqc_dt_ids[] = {
        { .compatible = "renesas,rza1-irqc" },
        {},
};
MODULE_DEVICE_TABLE(of, rza1_irqc_dt_ids);

static struct platform_driver rza1_irqc_device_driver = {
        .probe          = rza1_irqc_probe,
        .remove         = rza1_irqc_remove,
        .driver         = {
                .name           = "renesas_rza1_irqc",
                .of_match_table = rza1_irqc_dt_ids,
        }
};

static int __init rza1_irqc_init(void)
{
        return platform_driver_register(&rza1_irqc_device_driver);
}
postcore_initcall(rza1_irqc_init);

static void __exit rza1_irqc_exit(void)
{
        platform_driver_unregister(&rza1_irqc_device_driver);
}
module_exit(rza1_irqc_exit);

MODULE_AUTHOR("Geert Uytterhoeven <geert+renesas@glider.be>");
MODULE_DESCRIPTION("Renesas RZ/A1 IRQC Driver");