/*      $NetBSD: dmac.c,v 1.12 2014/03/31 11:25:49 martin Exp $ */

/*-
 * Copyright (c) 2001 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by UCHIYAMA Yasushi.
 *
 * 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: dmac.c,v 1.12 2014/03/31 11:25:49 martin Exp $");

#include "debug_playstation2.h"

#include <sys/param.h>
#include <sys/systm.h>

#include <mips/cache.h>

#include <playstation2/ee/eevar.h>
#include <playstation2/ee/dmacvar.h>
#include <playstation2/ee/dmacreg.h>
#include <playstation2/ee/gsvar.h>      /* debug monitor */

#include <playstation2/playstation2/interrupt.h>

#ifdef DEBUG
#define LEGAL_CHANNEL(x)        ((x) >= 0 && (x) <= 15)
#define STATIC
#else
#define STATIC  static
#endif

#define _DMAC_NINTR     10

STATIC vaddr_t __dmac_channel_base[_DMAC_NINTR] = {
        D0_REGBASE,
        D1_REGBASE,
        D2_REGBASE,
        D3_REGBASE,
        D4_REGBASE,
        D5_REGBASE,
        D6_REGBASE,
        D7_REGBASE,
        D8_REGBASE,
        D9_REGBASE
};

u_int32_t __dmac_enabled_channel;

STATIC int __dmac_initialized;
STATIC struct _ipl_dispatcher __dmac_dispatcher[_DMAC_NINTR];
STATIC struct _ipl_holder __dmac_ipl_holder[_IPL_N];
STATIC SLIST_HEAD(, _ipl_dispatcher) __dmac_dispatcher_head =
 SLIST_HEAD_INITIALIZER(__dmac_dispatcher_head);

void
dmac_init(void)
{
        int i;

        if (__dmac_initialized++)
                return;

        /* disable DMAC */
        _reg_write_4(D_ENABLEW_REG, D_ENABLE_SUSPEND);

        /* disable all interrupt */
        for (i = 0; i < _DMAC_NINTR; i++)
                dmac_intr_disable(i);

        for (i = 0; i < _IPL_N; i++)
                __dmac_ipl_holder[i].mask = 0xffffffff;

        if (_reg_read_4(D_STAT_REG) & D_STAT_SIM)
                _reg_write_4(D_STAT_REG, D_STAT_SIM);
        if (_reg_read_4(D_STAT_REG) & D_STAT_MEIM)
                _reg_write_4(D_STAT_REG, D_STAT_MEIM);

        /* clear all status */
        _reg_write_4(D_STAT_REG, _reg_read_4(D_STAT_REG) & D_STAT_CIS_MASK);

        /* enable DMAC */
        _reg_write_4(D_ENABLEW_REG, 0);
        _reg_write_4(D_CTRL_REG, D_CTRL_DMAE);
}

/*
 * Interrupt
 */
int
dmac_intr(u_int32_t mask)
{
        struct _ipl_dispatcher *dispatcher;
        u_int32_t r, dispatch, pending;

        r = _reg_read_4(D_STAT_REG);
        mask = D_STAT_CIM(mask);
        dispatch = r & ~mask & __dmac_enabled_channel;
        pending = r & mask & __dmac_enabled_channel;
#if 0
        __gsfb_print(2,
            "DMAC stat=%08x, mask=%08x, pend=%08x, disp=%08x enable=%08x\n",
            r, mask, pending, dispatch, __dmac_enabled_channel);
#endif
        if (dispatch == 0)
                return (pending == 0 ? 1 : 0);

        /* clear interrupt */
        _reg_write_4(D_STAT_REG, dispatch);
        
        /* dispatch interrupt handler */
        SLIST_FOREACH(dispatcher, &__dmac_dispatcher_head, link) {
                if (dispatcher->bit & dispatch) {
                        KDASSERT(dispatcher->func);
                        (*dispatcher->func)(dispatcher->arg);
                        dispatch &= ~dispatcher->bit;
                }
        }

        /* disable spurious interrupt source */
        if (dispatch) {
                int i, bit;
                for (i = 0, bit = 1; i < _DMAC_NINTR; i++, bit <<= 1) {
                        if (bit & dispatch) {
                                dmac_intr_disable(i);
                                printf("%s: spurious interrupt %d disabled.\n",
                                    __func__, i);
                        }
                }
        }


        return (pending == 0 ? 1 : 0);
}

void
dmac_intr_enable(enum dmac_channel ch)
{
        u_int32_t mask;

        KDASSERT(LEGAL_CHANNEL(ch));

        mask = D_STAT_CIM_BIT(ch);
        _reg_write_4(D_STAT_REG, (_reg_read_4(D_STAT_REG) & mask) ^ mask);
}

void
dmac_intr_disable(enum dmac_channel ch)
{
        KDASSERT(LEGAL_CHANNEL(ch));

        _reg_write_4(D_STAT_REG, _reg_read_4(D_STAT_REG) & D_STAT_CIM_BIT(ch));
}

void
dmac_update_mask(u_int32_t mask)
{
        u_int32_t cur_mask;

        mask = D_STAT_CIM(mask);
        cur_mask = _reg_read_4(D_STAT_REG);
        
        _reg_write_4(D_STAT_REG, ((cur_mask ^ ~mask) | (cur_mask & mask)) &
            D_STAT_CIM(__dmac_enabled_channel));
}

void *
dmac_intr_establish(enum dmac_channel ch, int ipl, int (*func)(void *),
    void *arg)
{
        struct _ipl_dispatcher *dispatcher = &__dmac_dispatcher[ch];
        struct _ipl_dispatcher *d;
        int i, s;

        KDASSERT(dispatcher->func == NULL);
        
        s = _intr_suspend();
        dispatcher->func = func;
        dispatcher->arg = arg;
        dispatcher->ipl = ipl;
        dispatcher->channel = ch;
        dispatcher->bit = D_STAT_CIS_BIT(ch);

        for (i = 0; i < _IPL_N; i++) {
                if (i < ipl)
                        __dmac_ipl_holder[i].mask &= ~D_STAT_CIM_BIT(ch);
                else
                        __dmac_ipl_holder[i].mask |= D_STAT_CIM_BIT(ch);
        }

        /* insert queue IPL order */
        if (SLIST_EMPTY(&__dmac_dispatcher_head)) {
                SLIST_INSERT_HEAD(&__dmac_dispatcher_head, dispatcher, link);
        } else {
                SLIST_FOREACH(d, &__dmac_dispatcher_head, link) {
                        if (SLIST_NEXT(d, link) == 0 ||
                            SLIST_NEXT(d, link)->ipl < ipl) {
                                SLIST_INSERT_AFTER(d, dispatcher, link);
                                break;
                        }
                }
        }

        md_ipl_register(IPL_DMAC, __dmac_ipl_holder);

        dmac_intr_enable(ch);
        __dmac_enabled_channel |= D_STAT_CIS_BIT(ch);

        _intr_resume(s);
        
        return ((void *)ch);
}

void
dmac_intr_disestablish(void *handle)
{
        int ch = (int)(handle);
        struct _ipl_dispatcher *dispatcher = &__dmac_dispatcher[ch];
        int i, s;

        s = _intr_suspend();

        dmac_intr_disable(ch);
        dispatcher->func = NULL;

        SLIST_REMOVE(&__dmac_dispatcher_head, dispatcher,
            _ipl_dispatcher, link);

        for (i = 0; i < _IPL_N; i++)
                __dmac_ipl_holder[i].mask |= D_STAT_CIM_BIT(ch);

        md_ipl_register(IPL_DMAC, __dmac_ipl_holder);
        __dmac_enabled_channel &= ~D_STAT_CIS_BIT(ch);

        _intr_resume(s);
}

/*
 * Start/Stop
 */
void
dmac_start_channel(enum dmac_channel ch)
{
        bus_addr_t chcr = D_CHCR_REG(__dmac_channel_base[ch]);
        u_int32_t r;
        int s;

        /* suspend all channels */
        s = _intr_suspend();
        r = _reg_read_4(D_ENABLER_REG);
        _reg_write_4(D_ENABLEW_REG, r | D_ENABLE_SUSPEND);

        /* access CHCR */
        _reg_write_4(chcr, (_reg_read_4(chcr) | D_CHCR_STR));

        /* start all channels */
        _reg_write_4(D_ENABLEW_REG, r & ~D_ENABLE_SUSPEND);
        _intr_resume(s);
}

void
dmac_stop_channel(enum dmac_channel ch)
{
        bus_addr_t chcr = D_CHCR_REG(__dmac_channel_base[ch]);
        u_int32_t r;
        int s;

        /* suspend all channels */
        s = _intr_suspend();
        r = _reg_read_4(D_ENABLER_REG);
        _reg_write_4(D_ENABLEW_REG, r | D_ENABLE_SUSPEND);

        /* access CHCR */
        _reg_write_4(chcr, (_reg_read_4(chcr) & ~D_CHCR_STR));

        /* resume all chanells */
        _reg_write_4(D_ENABLEW_REG, r);
        _intr_resume(s);
}

void
dmac_sync_buffer(void)
{

        mips_dcache_wbinv_all();
        __asm volatile("sync.l");
}

/*
 * Polling
 *   DMAC status connected to CPCOND[0].
 */
void
dmac_cpc_set(enum dmac_channel ch)
{
        u_int32_t r;

        r = _reg_read_4(D_PCR_REG);
        KDASSERT((D_PCR_CPC(r) & ~D_PCR_CPC_BIT(ch)) == 0);
        
        /* clear interrupt status */
        _reg_write_4(D_STAT_REG, D_STAT_CIS_BIT(ch));
        
        _reg_write_4(D_PCR_REG, r | D_PCR_CPC_BIT(ch));
}

void
dmac_cpc_clear(enum dmac_channel ch)
{

        _reg_write_4(D_PCR_REG, _reg_read_4(D_PCR_REG) & ~D_PCR_CPC_BIT(ch))
}

void
dmac_cpc_poll(void)
{
        __asm volatile(
                ".set noreorder;"
        "1:      nop;"
                "nop;"
                "nop;"
                "nop;"
                "nop;"
                "bc0f 1b;"
                " nop;"
                ".set reorder");
}

/* not recommended. use dmac_cpc_poll as possible */
void
dmac_bus_poll(enum dmac_channel ch)
{
        bus_addr_t chcr = D_CHCR_REG(__dmac_channel_base[ch]);

        while (_reg_read_4(chcr) & D_CHCR_STR)
                ;
}

/*
 * Misc
 */
void
dmac_chcr_write(enum dmac_channel ch, u_int32_t v)
{
        u_int32_t r;
        int s;

        /* suspend all channels */
        s = _intr_suspend();
        r = _reg_read_4(D_ENABLER_REG);
        _reg_write_4(D_ENABLEW_REG, r | D_ENABLE_SUSPEND);

        /* write CHCR reg */
        _reg_write_4(D_CHCR_REG(__dmac_channel_base[ch]), v);

        /* resume all chanells */
        _reg_write_4(D_ENABLEW_REG, r);
        _intr_resume(s);
}