root/drivers/irqchip/irq-clps711x.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  CLPS711X IRQ driver
 *
 *  Copyright (C) 2013 Alexander Shiyan <shc_work@mail.ru>
 */

#include <linux/io.h>
#include <linux/irq.h>
#include <linux/irqchip.h>
#include <linux/irqdomain.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/slab.h>

#include <asm/exception.h>
#include <asm/mach/irq.h>

#define CLPS711X_INTSR1 (0x0240)
#define CLPS711X_INTMR1 (0x0280)
#define CLPS711X_BLEOI  (0x0600)
#define CLPS711X_MCEOI  (0x0640)
#define CLPS711X_TEOI   (0x0680)
#define CLPS711X_TC1EOI (0x06c0)
#define CLPS711X_TC2EOI (0x0700)
#define CLPS711X_RTCEOI (0x0740)
#define CLPS711X_UMSEOI (0x0780)
#define CLPS711X_COEOI  (0x07c0)
#define CLPS711X_INTSR2 (0x1240)
#define CLPS711X_INTMR2 (0x1280)
#define CLPS711X_SRXEOF (0x1600)
#define CLPS711X_KBDEOI (0x1700)
#define CLPS711X_INTSR3 (0x2240)
#define CLPS711X_INTMR3 (0x2280)

static const struct {
#define CLPS711X_FLAG_EN        (1 << 0)
#define CLPS711X_FLAG_FIQ       (1 << 1)
        unsigned int    flags;
        phys_addr_t     eoi;
} clps711x_irqs[] = {
        [1]     = { CLPS711X_FLAG_FIQ, CLPS711X_BLEOI, },
        [3]     = { CLPS711X_FLAG_FIQ, CLPS711X_MCEOI, },
        [4]     = { CLPS711X_FLAG_EN, CLPS711X_COEOI, },
        [5]     = { CLPS711X_FLAG_EN, },
        [6]     = { CLPS711X_FLAG_EN, },
        [7]     = { CLPS711X_FLAG_EN, },
        [8]     = { CLPS711X_FLAG_EN, CLPS711X_TC1EOI, },
        [9]     = { CLPS711X_FLAG_EN, CLPS711X_TC2EOI, },
        [10]    = { CLPS711X_FLAG_EN, CLPS711X_RTCEOI, },
        [11]    = { CLPS711X_FLAG_EN, CLPS711X_TEOI, },
        [12]    = { CLPS711X_FLAG_EN, },
        [13]    = { CLPS711X_FLAG_EN, },
        [14]    = { CLPS711X_FLAG_EN, CLPS711X_UMSEOI, },
        [15]    = { CLPS711X_FLAG_EN, CLPS711X_SRXEOF, },
        [16]    = { CLPS711X_FLAG_EN, CLPS711X_KBDEOI, },
        [17]    = { CLPS711X_FLAG_EN, },
        [18]    = { CLPS711X_FLAG_EN, },
        [28]    = { CLPS711X_FLAG_EN, },
        [29]    = { CLPS711X_FLAG_EN, },
        [32]    = { CLPS711X_FLAG_FIQ, },
};

static struct {
        void __iomem            *base;
        void __iomem            *intmr[3];
        void __iomem            *intsr[3];
        struct irq_domain       *domain;
        struct irq_domain_ops   ops;
} *clps711x_intc;

static void __exception_irq_entry clps711x_irqh(struct pt_regs *regs)
{
        u32 irqstat;

        do {
                irqstat = readw_relaxed(clps711x_intc->intmr[0]) &
                          readw_relaxed(clps711x_intc->intsr[0]);
                if (irqstat)
                        generic_handle_domain_irq(clps711x_intc->domain,
                                                  fls(irqstat) - 1);

                irqstat = readw_relaxed(clps711x_intc->intmr[1]) &
                          readw_relaxed(clps711x_intc->intsr[1]);
                if (irqstat)
                        generic_handle_domain_irq(clps711x_intc->domain,
                                                  fls(irqstat) - 1 + 16);
        } while (irqstat);
}

static void clps711x_intc_eoi(struct irq_data *d)
{
        irq_hw_number_t hwirq = irqd_to_hwirq(d);

        writel_relaxed(0, clps711x_intc->base + clps711x_irqs[hwirq].eoi);
}

static void clps711x_intc_mask(struct irq_data *d)
{
        irq_hw_number_t hwirq = irqd_to_hwirq(d);
        void __iomem *intmr = clps711x_intc->intmr[hwirq / 16];
        u32 tmp;

        tmp = readl_relaxed(intmr);
        tmp &= ~(1 << (hwirq % 16));
        writel_relaxed(tmp, intmr);
}

static void clps711x_intc_unmask(struct irq_data *d)
{
        irq_hw_number_t hwirq = irqd_to_hwirq(d);
        void __iomem *intmr = clps711x_intc->intmr[hwirq / 16];
        u32 tmp;

        tmp = readl_relaxed(intmr);
        tmp |= 1 << (hwirq % 16);
        writel_relaxed(tmp, intmr);
}

static struct irq_chip clps711x_intc_chip = {
        .name           = "clps711x-intc",
        .irq_eoi        = clps711x_intc_eoi,
        .irq_mask       = clps711x_intc_mask,
        .irq_unmask     = clps711x_intc_unmask,
};

static int __init clps711x_intc_irq_map(struct irq_domain *h, unsigned int virq,
                                        irq_hw_number_t hw)
{
        irq_flow_handler_t handler = handle_level_irq;
        unsigned int flags = 0;

        if (!clps711x_irqs[hw].flags)
                return 0;

        if (clps711x_irqs[hw].flags & CLPS711X_FLAG_FIQ) {
                handler = handle_bad_irq;
                flags |= IRQ_NOAUTOEN;
        } else if (clps711x_irqs[hw].eoi) {
                handler = handle_fasteoi_irq;
        }

        /* Clear down pending interrupt */
        if (clps711x_irqs[hw].eoi)
                writel_relaxed(0, clps711x_intc->base + clps711x_irqs[hw].eoi);

        irq_set_chip_and_handler(virq, &clps711x_intc_chip, handler);
        irq_modify_status(virq, IRQ_NOPROBE, flags);

        return 0;
}

static int __init _clps711x_intc_init(struct device_node *np,
                                      phys_addr_t base, resource_size_t size)
{
        int err;

        clps711x_intc = kzalloc_obj(*clps711x_intc);
        if (!clps711x_intc)
                return -ENOMEM;

        clps711x_intc->base = ioremap(base, size);
        if (!clps711x_intc->base) {
                err = -ENOMEM;
                goto out_kfree;
        }

        clps711x_intc->intsr[0] = clps711x_intc->base + CLPS711X_INTSR1;
        clps711x_intc->intmr[0] = clps711x_intc->base + CLPS711X_INTMR1;
        clps711x_intc->intsr[1] = clps711x_intc->base + CLPS711X_INTSR2;
        clps711x_intc->intmr[1] = clps711x_intc->base + CLPS711X_INTMR2;
        clps711x_intc->intsr[2] = clps711x_intc->base + CLPS711X_INTSR3;
        clps711x_intc->intmr[2] = clps711x_intc->base + CLPS711X_INTMR3;

        /* Mask all interrupts */
        writel_relaxed(0, clps711x_intc->intmr[0]);
        writel_relaxed(0, clps711x_intc->intmr[1]);
        writel_relaxed(0, clps711x_intc->intmr[2]);

        err = irq_alloc_descs(-1, 0, ARRAY_SIZE(clps711x_irqs), numa_node_id());
        if (err < 0)
                goto out_iounmap;

        clps711x_intc->ops.map = clps711x_intc_irq_map;
        clps711x_intc->ops.xlate = irq_domain_xlate_onecell;
        clps711x_intc->domain =
                irq_domain_create_legacy(of_fwnode_handle(np), ARRAY_SIZE(clps711x_irqs), 0, 0,
                                         &clps711x_intc->ops, NULL);
        if (!clps711x_intc->domain) {
                err = -ENOMEM;
                goto out_irqfree;
        }

        irq_set_default_domain(clps711x_intc->domain);
        set_handle_irq(clps711x_irqh);

#ifdef CONFIG_FIQ
        init_FIQ(0);
#endif

        return 0;

out_irqfree:
        irq_free_descs(0, ARRAY_SIZE(clps711x_irqs));

out_iounmap:
        iounmap(clps711x_intc->base);

out_kfree:
        kfree(clps711x_intc);

        return err;
}

static int __init clps711x_intc_init_dt(struct device_node *np,
                                        struct device_node *parent)
{
        struct resource res;
        int err;

        err = of_address_to_resource(np, 0, &res);
        if (err)
                return err;

        return _clps711x_intc_init(np, res.start, resource_size(&res));
}
IRQCHIP_DECLARE(clps711x, "cirrus,ep7209-intc", clps711x_intc_init_dt);