/*      $NetBSD: windermere.c,v 1.3 2021/08/07 16:18:48 thorpej Exp $   */
/*
 * Copyright (c) 2012 KIYOHARA Takashi
 * 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 AUTHOR ``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 AUTHOR 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: windermere.c,v 1.3 2021/08/07 16:18:48 thorpej Exp $");

#include "opt_com.h"

#define _INTR_PRIVATE

#include <sys/param.h>
#include <sys/bus.h>
#include <sys/device.h>
#include <sys/errno.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/timetc.h>
#include <sys/types.h>

#include <arm/mainbus/mainbus.h>
#include <arm/pic/picvar.h>

#include <machine/epoc32.h>
#include <machine/limits.h>

#include <epoc32/windermere/windermerereg.h>
#include <epoc32/windermere/windermerevar.h>

#include "locators.h"


static int windermere_match(device_t, cfdata_t, void *);
static void windermere_attach(device_t parent, device_t self, void *aux);

static int windermere_print(void *, const char *);
static int windermere_submatch(device_t, cfdata_t, const int *, void *);

static int windermere_find_pending_irqs(void);

static void windermere_pic_unblock_irqs(struct pic_softc *, size_t, uint32_t);
static void windermere_pic_block_irqs(struct pic_softc *, size_t, uint32_t);
static void windermere_pic_establish_irq(struct pic_softc *,
                                         struct intrsource *);

#define TC_READ(base, off)              (*((base) + (off)))
#define TC_WRITE(base, off, val)        (*((base) + (off)) = (val))
static void windermere_initclocks(void);
static int windermere_clockintr(void *);
static void windermere_tc_init(void);
static u_int windermere_get_timecount(struct timecounter *);

static void windermere_delay(unsigned int);

CFATTACH_DECL_NEW(windermere, 0,
    windermere_match, windermere_attach, NULL, NULL);

static const struct {
        const char *name;
        bus_addr_t offset;
        int irq;
} windermere_periphs[] = {
        { "wmlcd",      0x200, WINDERMERECF_IRQ_DEFAULT },
        { "wmcom",      0x600, 12 },
        { "wmcom",      0x700, 13 },
        { "wmrtc",      0xd00, 10 },
        { "wmpm",       WINDERMERECF_OFFSET_DEFAULT, WINDERMERECF_IRQ_DEFAULT },
        { "wmaudio",    WINDERMERECF_OFFSET_DEFAULT, WINDERMERECF_IRQ_DEFAULT },
        { "wmkbd",      0xe28, WINDERMERECF_IRQ_DEFAULT },
};

static struct pic_ops windermere_picops = {
        .pic_unblock_irqs = windermere_pic_unblock_irqs,
        .pic_block_irqs = windermere_pic_block_irqs,
        .pic_establish_irq = windermere_pic_establish_irq,
};
static struct pic_softc windermere_pic = {
        .pic_ops = &windermere_picops,
        .pic_maxsources = 16,
        .pic_name = "windermere",
};
static uint16_t pic_mask = 0x0000;

/* ARGSUSED */
static int
windermere_match(device_t parent, cfdata_t match, void *aux)
{

        return 1;
}

/* ARGSUSED */
static void
windermere_attach(device_t parent, device_t self, void *aux)
{
        struct mainbus_attach_args *maa = aux;
        struct windermere_attach_args aa;
        bus_space_handle_t ioh;
        int i;

        aprint_naive("\n");
        aprint_normal("\n");

        if (bus_space_map(maa->mb_iot, maa->mb_iobase, ARM7XX_INTRREG_SIZE, 0,
                                                                &ioh) != 0) {
                aprint_error_dev(self, "can't map registers\n");
                return;
        }

        pic_add(&windermere_pic, 0);
        soc_find_pending_irqs = windermere_find_pending_irqs;
        soc_initclocks = windermere_initclocks;
        soc_delay = windermere_delay;

        for (i = 0; i < __arraycount(windermere_periphs); i++) {
                aa.aa_name = windermere_periphs[i].name;
                aa.aa_iot = maa->mb_iot;
                aa.aa_ioh = &ioh;
                aa.aa_offset = windermere_periphs[i].offset;
                aa.aa_size = 0;
                aa.aa_irq = windermere_periphs[i].irq;

                config_found(self, &aa, windermere_print,
                    CFARGS(.submatch = windermere_submatch));
        }
}

static int
windermere_print(void *aux, const char *pnp)
{
        struct windermere_attach_args *aa = aux;

        if (pnp)
                aprint_normal("%s at %s", aa->aa_name, pnp);
        else {
                if (aa->aa_offset != WINDERMERECF_OFFSET_DEFAULT) {
                        aprint_normal(" offset 0x%04lx", aa->aa_offset);
                        if (aa->aa_size > 0)
                                aprint_normal("-0x%04lx",
                                    aa->aa_offset + aa->aa_size - 1);
                }
                if (aa->aa_irq != WINDERMERECF_IRQ_DEFAULT)
                        aprint_normal(" irq %d", aa->aa_irq);
        }

        return UNCONF;
}

/* ARGSUSED */
static int
windermere_submatch(device_t parent, cfdata_t cf, const int *ldesc, void *aux)
{
        struct windermere_attach_args *aa = aux;

        /*
         * special case. match *kbd@windermere.
         * Windermere helps implement to machine-dependent keyboard.
         */
        if (strcmp(aa->aa_name, "wmkbd") == 0 &&
            strcmp(cf->cf_name + strlen(cf->cf_name) - 3, "kbd") == 0)
                return config_match(parent, cf, aux);

        if (strcmp(cf->cf_name, aa->aa_name) != 0)
                return 0;
        return config_match(parent, cf, aux);
}


static int
windermere_find_pending_irqs(void)
{
        volatile uint32_t *intr =
            (uint32_t *)(ARM7XX_INTRREG_VBASE + WINDERMERE_INTR_OFFSET);
        uint16_t pending;

        pending = *(intr + INTSR);
        if (pending & ~pic_mask) {
                *(intr + INTENC) = pending & ~pic_mask;
                printf("stray interrupt pending: 0x%04x\n",
                    pending & ~pic_mask);
                pending &= pic_mask;
        }
        if (pending == 0)
                return 0;

        return pic_mark_pending_sources(&windermere_pic, 0, pending);
}

/* ARGSUSED */
static void
windermere_pic_unblock_irqs(struct pic_softc *pic, size_t irqbase,
                            uint32_t irq_mask)
{
        volatile uint32_t *intr =
            (uint32_t *)(ARM7XX_INTRREG_VBASE + WINDERMERE_INTR_OFFSET);

        *(intr + INTENS) = irq_mask;
        pic_mask |= irq_mask;
}

/* ARGSUSED */
static void
windermere_pic_block_irqs(struct pic_softc *pic, size_t irqbase,
                          uint32_t irq_mask)
{
        volatile uint32_t *intr =
            (uint32_t *)(ARM7XX_INTRREG_VBASE + WINDERMERE_INTR_OFFSET);

        *(intr + INTENC) = irq_mask;
        pic_mask &= ~irq_mask;
}

static void
windermere_pic_establish_irq(struct pic_softc *pic, struct intrsource *is)
{
        /* Nothing */
}

static void
windermere_initclocks(void)
{
        volatile uint32_t *tc1, *tc2;
        uint32_t ctrl;

        tc1 =
         (uint32_t *)(ARM7XX_INTRREG_VBASE + WINDERMERE_TC_OFFSET + TC1_OFFSET);
        tc2 =
         (uint32_t *)(ARM7XX_INTRREG_VBASE + WINDERMERE_TC_OFFSET + TC2_OFFSET);

        /* set clock to TC1 */ 
        ctrl = TC_READ(tc1, TC_CTRL);
        ctrl |= (CTRL_CLKSEL | CTRL_MODE | CTRL_ENABLE); /* select 512kHz */
        TC_WRITE(tc1, TC_CTRL, ctrl);
        TC_WRITE(tc1, TC_LOAD, 512 * 1000 / hz - 1);    /* 512kHz / hz - 1 */
        intr_establish(8, IPL_CLOCK, 0, windermere_clockintr, NULL);

        /* set delay counter */ 
        ctrl = TC_READ(tc2, TC_CTRL);
        ctrl |= (CTRL_CLKSEL | CTRL_MODE | CTRL_ENABLE); /* select 512kHz */
        TC_WRITE(tc2, TC_CTRL, ctrl);
        TC_WRITE(tc2, TC_LOAD, TC_MAX);

        windermere_tc_init();
}

static int
windermere_clockintr(void *arg)
{
        volatile uint32_t *tc1;

        tc1 =
         (uint32_t *)(ARM7XX_INTRREG_VBASE + WINDERMERE_TC_OFFSET + TC1_OFFSET);
        TC_WRITE(tc1, TC_EOI, EOI_EOI);

        hardclock(arg);

        return 1;
}

static void
windermere_tc_init(void)
{
        static struct timecounter windermere_tc = {
                .tc_get_timecount = windermere_get_timecount,
                .tc_counter_mask = TC_MASK,
                .tc_frequency = 512000,
                .tc_name = "windermere",
                .tc_quality = 100,
        };

        tc_init(&windermere_tc);
}

static u_int
windermere_get_timecount(struct timecounter *tc)
{
        volatile uint32_t *tc2;

        tc2 =
         (uint32_t *)(ARM7XX_INTRREG_VBASE + WINDERMERE_TC_OFFSET + TC2_OFFSET);

        return TC_READ(tc2, TC_VAL) ^ TC_MASK;  /* It is decremental counter */
}

static void
windermere_delay(unsigned int us)
{
        volatile uint32_t *tc2;
        int prev, now, remaining;

        tc2 =
         (uint32_t *)(ARM7XX_INTRREG_VBASE + WINDERMERE_TC_OFFSET + TC2_OFFSET);

        prev = TC_READ(tc2, TC_VAL) & TC_MASK;
        remaining = us * 512 / 1000 + 1;

        while (remaining > 0) {
                now = TC_READ(tc2, TC_VAL) & TC_MASK;
                if (now >= prev)
                        remaining -= (now - prev);
                else
                        remaining -= (USHRT_MAX - now + prev + 1);
                prev = now;
        }
}