root/drivers/irqchip/irq-uniphier-aidet.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Driver for UniPhier AIDET (ARM Interrupt Detector)
 *
 * Copyright (C) 2017 Socionext Inc.
 *   Author: Masahiro Yamada <yamada.masahiro@socionext.com>
 */

#include <linux/bitops.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/irqdomain.h>
#include <linux/kernel.h>
#include <linux/of.h>
#include <linux/of_irq.h>
#include <linux/platform_device.h>
#include <linux/spinlock.h>

#define UNIPHIER_AIDET_NR_IRQS          256

#define UNIPHIER_AIDET_DETCONF          0x04    /* inverter register base */

struct uniphier_aidet_priv {
        struct irq_domain *domain;
        void __iomem *reg_base;
        spinlock_t lock;
        u32 saved_vals[UNIPHIER_AIDET_NR_IRQS / 32];
};

static void uniphier_aidet_reg_update(struct uniphier_aidet_priv *priv,
                                      unsigned int reg, u32 mask, u32 val)
{
        unsigned long flags;
        u32 tmp;

        spin_lock_irqsave(&priv->lock, flags);
        tmp = readl_relaxed(priv->reg_base + reg);
        tmp &= ~mask;
        tmp |= mask & val;
        writel_relaxed(tmp, priv->reg_base + reg);
        spin_unlock_irqrestore(&priv->lock, flags);
}

static void uniphier_aidet_detconf_update(struct uniphier_aidet_priv *priv,
                                          unsigned long index, unsigned int val)
{
        unsigned int reg;
        u32 mask;

        reg = UNIPHIER_AIDET_DETCONF + index / 32 * 4;
        mask = BIT(index % 32);

        uniphier_aidet_reg_update(priv, reg, mask, val ? mask : 0);
}

static int uniphier_aidet_irq_set_type(struct irq_data *data, unsigned int type)
{
        struct uniphier_aidet_priv *priv = data->chip_data;
        unsigned int val;

        /* enable inverter for active low triggers */
        switch (type) {
        case IRQ_TYPE_EDGE_RISING:
        case IRQ_TYPE_LEVEL_HIGH:
                val = 0;
                break;
        case IRQ_TYPE_EDGE_FALLING:
                val = 1;
                type = IRQ_TYPE_EDGE_RISING;
                break;
        case IRQ_TYPE_LEVEL_LOW:
                val = 1;
                type = IRQ_TYPE_LEVEL_HIGH;
                break;
        default:
                return -EINVAL;
        }

        uniphier_aidet_detconf_update(priv, data->hwirq, val);

        return irq_chip_set_type_parent(data, type);
}

static struct irq_chip uniphier_aidet_irq_chip = {
        .name = "AIDET",
        .irq_mask = irq_chip_mask_parent,
        .irq_unmask = irq_chip_unmask_parent,
        .irq_eoi = irq_chip_eoi_parent,
        .irq_set_affinity = irq_chip_set_affinity_parent,
        .irq_set_type = uniphier_aidet_irq_set_type,
};

static int uniphier_aidet_domain_translate(struct irq_domain *domain,
                                           struct irq_fwspec *fwspec,
                                           unsigned long *out_hwirq,
                                           unsigned int *out_type)
{
        if (WARN_ON(fwspec->param_count < 2))
                return -EINVAL;

        *out_hwirq = fwspec->param[0];
        *out_type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;

        return 0;
}

static int uniphier_aidet_domain_alloc(struct irq_domain *domain,
                                       unsigned int virq, unsigned int nr_irqs,
                                       void *arg)
{
        struct irq_fwspec parent_fwspec;
        irq_hw_number_t hwirq;
        unsigned int type;
        int ret;

        if (nr_irqs != 1)
                return -EINVAL;

        ret = uniphier_aidet_domain_translate(domain, arg, &hwirq, &type);
        if (ret)
                return ret;

        switch (type) {
        case IRQ_TYPE_EDGE_RISING:
        case IRQ_TYPE_LEVEL_HIGH:
                break;
        case IRQ_TYPE_EDGE_FALLING:
                type = IRQ_TYPE_EDGE_RISING;
                break;
        case IRQ_TYPE_LEVEL_LOW:
                type = IRQ_TYPE_LEVEL_HIGH;
                break;
        default:
                return -EINVAL;
        }

        if (hwirq >= UNIPHIER_AIDET_NR_IRQS)
                return -ENXIO;

        ret = irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
                                            &uniphier_aidet_irq_chip,
                                            domain->host_data);
        if (ret)
                return ret;

        /* parent is GIC */
        parent_fwspec.fwnode = domain->parent->fwnode;
        parent_fwspec.param_count = 3;
        parent_fwspec.param[0] = 0;             /* SPI */
        parent_fwspec.param[1] = hwirq;
        parent_fwspec.param[2] = type;

        return irq_domain_alloc_irqs_parent(domain, virq, 1, &parent_fwspec);
}

static const struct irq_domain_ops uniphier_aidet_domain_ops = {
        .alloc = uniphier_aidet_domain_alloc,
        .free = irq_domain_free_irqs_common,
        .translate = uniphier_aidet_domain_translate,
};

static int uniphier_aidet_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct device_node *parent_np;
        struct irq_domain *parent_domain;
        struct uniphier_aidet_priv *priv;

        parent_np = of_irq_find_parent(dev->of_node);
        if (!parent_np)
                return -ENXIO;

        parent_domain = irq_find_host(parent_np);
        of_node_put(parent_np);
        if (!parent_domain)
                return -EPROBE_DEFER;

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

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

        spin_lock_init(&priv->lock);

        priv->domain = irq_domain_create_hierarchy(
                                        parent_domain, 0,
                                        UNIPHIER_AIDET_NR_IRQS,
                                        of_fwnode_handle(dev->of_node),
                                        &uniphier_aidet_domain_ops, priv);
        if (!priv->domain)
                return -ENOMEM;

        platform_set_drvdata(pdev, priv);

        return 0;
}

static int __maybe_unused uniphier_aidet_suspend(struct device *dev)
{
        struct uniphier_aidet_priv *priv = dev_get_drvdata(dev);
        int i;

        for (i = 0; i < ARRAY_SIZE(priv->saved_vals); i++)
                priv->saved_vals[i] = readl_relaxed(
                        priv->reg_base + UNIPHIER_AIDET_DETCONF + i * 4);

        return 0;
}

static int __maybe_unused uniphier_aidet_resume(struct device *dev)
{
        struct uniphier_aidet_priv *priv = dev_get_drvdata(dev);
        int i;

        for (i = 0; i < ARRAY_SIZE(priv->saved_vals); i++)
                writel_relaxed(priv->saved_vals[i],
                               priv->reg_base + UNIPHIER_AIDET_DETCONF + i * 4);

        return 0;
}

static const struct dev_pm_ops uniphier_aidet_pm_ops = {
        SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(uniphier_aidet_suspend,
                                      uniphier_aidet_resume)
};

static const struct of_device_id uniphier_aidet_match[] = {
        { .compatible = "socionext,uniphier-ld4-aidet" },
        { .compatible = "socionext,uniphier-pro4-aidet" },
        { .compatible = "socionext,uniphier-sld8-aidet" },
        { .compatible = "socionext,uniphier-pro5-aidet" },
        { .compatible = "socionext,uniphier-pxs2-aidet" },
        { .compatible = "socionext,uniphier-ld11-aidet" },
        { .compatible = "socionext,uniphier-ld20-aidet" },
        { .compatible = "socionext,uniphier-pxs3-aidet" },
        { .compatible = "socionext,uniphier-nx1-aidet" },
        { /* sentinel */ }
};

static struct platform_driver uniphier_aidet_driver = {
        .probe = uniphier_aidet_probe,
        .driver = {
                .name = "uniphier-aidet",
                .of_match_table = uniphier_aidet_match,
                .pm = &uniphier_aidet_pm_ops,
        },
};
builtin_platform_driver(uniphier_aidet_driver);