/*      $NetBSD: pic_openpic.c,v 1.20 2022/02/23 21:54:40 andvar Exp $ */

/*-
 * Copyright (c) 2007 Michael Lorenz
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: pic_openpic.c,v 1.20 2022/02/23 21:54:40 andvar Exp $");

#ifdef _KERNEL_OPT
#include "opt_multiprocessor.h"
#endif

#include <sys/param.h>
#include <sys/kmem.h>
#include <sys/kernel.h>

#include <uvm/uvm_extern.h>

#include <machine/pio.h>
#include <powerpc/openpic.h>

#include <powerpc/pic/picvar.h>

static void opic_enable_irq(struct pic_ops *, int, int);
static void opic_disable_irq(struct pic_ops *, int);
static void opic_establish_irq(struct pic_ops*, int, int, int);

struct pic_ops *
setup_openpic(void *addr, int passthrough)
{
        struct openpic_ops *opicops;
        struct pic_ops *pic;
        int irq;
        u_int x;

        openpic_base = addr;
        opicops = kmem_alloc(sizeof(*opicops), KM_SLEEP);
        pic = &opicops->pic;

        x = openpic_read(OPENPIC_FEATURE);
        if (((x & 0x07ff0000) >> 16) == 0)
                panic("setup_openpic() called on distributed openpic");
        
        aprint_normal("OpenPIC Version 1.%d: "
            "Supports %d CPUs and %d interrupt sources.\n",
            x & 0xff, ((x & 0x1f00) >> 8) + 1, ((x & 0x07ff0000) >> 16) + 1);

        pic->pic_numintrs = IPI_VECTOR + 1;
        pic->pic_cookie = addr;
        pic->pic_enable_irq = opic_enable_irq;
        pic->pic_reenable_irq = opic_enable_irq;
        pic->pic_disable_irq = opic_disable_irq;
        pic->pic_get_irq = opic_get_irq;
        pic->pic_ack_irq = opic_ack_irq;
        pic->pic_establish_irq = opic_establish_irq;
        pic->pic_finish_setup = opic_finish_setup;
        opicops->isu = NULL;
        opicops->nrofisus = 0; /* internal only */
        opicops->flags = 0; /* no flags (yet) */
        opicops->irq_per = NULL; /* internal ISU only */
        strcpy(pic->pic_name, "openpic");
        pic_add(pic);

        /*
         * the following sequence should make the same effects as openpic
         * controller reset by writing a one at the self-clearing
         * OPENPIC_CONFIG_RESET bit.  Please check the document of your
         * OpenPIC compliant interrupt controller and see whether #else
         * portion can work as described.
         */
#if 1
        openpic_set_priority(0, 15);

        for (irq = 0; irq < (pic->pic_numintrs - 1); irq++) {
                /* make sure to keep disabled */
                openpic_write(OPENPIC_SRC_VECTOR(irq), OPENPIC_IMASK);
                /* send all interrupts to CPU 0 */
                openpic_write(OPENPIC_IDEST(irq), 1 << 0);
        }

        x = openpic_read(OPENPIC_CONFIG);
        if (passthrough)
                x &= ~OPENPIC_CONFIG_8259_PASSTHRU_DISABLE;
        else 
                x |= OPENPIC_CONFIG_8259_PASSTHRU_DISABLE;
        openpic_write(OPENPIC_CONFIG, x);

        openpic_write(OPENPIC_SPURIOUS_VECTOR, 0xff);

        openpic_set_priority(0, 0);

        /* clear all pending interrupts */
        for (irq = 0; irq < pic->pic_numintrs; irq++) {
                openpic_read_irq(0);
                openpic_eoi(0);
        }
#else
        irq = 0;
        openpic_write(OPENPIC_CONFIG, OPENPIC_CONFIG_RESET);
        do {
                x = openpic_read(OPENPIC_CONFIG);
        } while (x & OPENPIC_CONFIG_RESET); /* S1C bit */
        if (passthrough)
                x &= ~OPENPIC_CONFIG_8259_PASSTHRU_DISABLE;
        else 
                x |= OPENPIC_CONFIG_8259_PASSTHRU_DISABLE;
        openpic_write(OPENPIC_CONFIG, x);
        openpic_set_priority(0, 0);
#endif

#if 0
        printf("timebase freq=%d\n", openpic_read(0x10f0));
#endif
        return pic;
}

static void
opic_establish_irq(struct pic_ops *pic, int irq, int type, int pri)
{
        int realpri = uimax(1, uimin(15, pri));
        uint32_t x;

        x = irq;
        x |= OPENPIC_IMASK;

        if (type == IST_EDGE_RISING || type == IST_LEVEL_HIGH)
                x |= OPENPIC_POLARITY_POSITIVE;
        else
                x |= OPENPIC_POLARITY_NEGATIVE;

        if (type == IST_EDGE_FALLING || type == IST_EDGE_RISING)
                x |= OPENPIC_SENSE_EDGE;
        else
                x |= OPENPIC_SENSE_LEVEL;

        x |= realpri << OPENPIC_PRIORITY_SHIFT;
#ifdef MULTIPROCESSOR
        if (irq < IPI_VECTOR)
#endif 
                openpic_write(OPENPIC_SRC_VECTOR(irq), x);

        aprint_debug("%s: setting IRQ %d to priority %d\n", __func__, irq,
            realpri);
}

static void
opic_enable_irq(struct pic_ops *pic, int irq, int type)
{
        u_int x;
#ifdef MULTIPROCESSOR
        if (irq == IPI_VECTOR) return;
#endif
        x = openpic_read(OPENPIC_SRC_VECTOR(irq));
        x &= ~OPENPIC_IMASK;
        openpic_write(OPENPIC_SRC_VECTOR(irq), x);
}

static void
opic_disable_irq(struct pic_ops *pic, int irq)
{
        u_int x;

#ifdef MULTIPROCESSOR
        if (irq == IPI_VECTOR) return;
#endif
        x = openpic_read(OPENPIC_SRC_VECTOR(irq));
        x |= OPENPIC_IMASK;
        openpic_write(OPENPIC_SRC_VECTOR(irq), x);
}