/*      $NetBSD: px.c,v 1.41 2019/11/10 21:16:37 chs Exp $      */

/*-
 * Copyright (c) 1999, 2000, 2001 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Andrew Doran.
 *
 * 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.
 */

/*
 * Driver for DEC PixelStamp graphics adapters (PMAG-C).
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: px.c,v 1.41 2019/11/10 21:16:37 chs Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/device.h>
#include <sys/malloc.h>
#include <sys/callout.h>

#include <uvm/uvm.h>    /* XXX uvm_pageboot_alloc */

#if defined(pmax)
#include <mips/cpuregs.h>
#elif defined(alpha)
#include <alpha/alpha_cpu.h>
#endif

#include <machine/autoconf.h>
#include <sys/cpu.h>
#include <sys/bus.h>

#include <dev/cons.h>

#include <dev/wscons/wsconsio.h>
#include <dev/wscons/wsdisplayvar.h>

#include <dev/ic/bt459reg.h>

#include <dev/tc/tcvar.h>
#include <dev/tc/sticreg.h>
#include <dev/tc/sticio.h>
#include <dev/tc/sticvar.h>

#define PX_STIC_POLL_OFFSET     0x000000        /* STIC DMA poll space */
#define PX_STAMP_OFFSET         0x0c0000        /* pixelstamp space on STIC */
#define PX_STIC_OFFSET          0x180000        /* STIC registers */
#define PX_VDAC_OFFSET          0x200000        /* VDAC registers (bt459) */
#define PX_VDAC_RESET_OFFSET    0x300000        /* VDAC reset register */
#define PX_ROM_OFFSET           0x300000        /* ROM code */

#define PX_BUF_COUNT            16
#define PX_BUF_INC(x)           ((x + 1) & (PX_BUF_COUNT - 1))

/*
 * We need enough aligned memory to hold:
 *
 * - Xserver communication area (4096 bytes)
 * - 16 packet buffers (4096 bytes each)
 * - 2 image buffers (5120 bytes each)
 *
 */
#define PX_BUF_SIZE             \
    (STIC_PACKET_SIZE * PX_BUF_COUNT + STIC_IMGBUF_SIZE*2 + STIC_XCOMM_SIZE)
#define PX_BUF_ALIGN            32768

#define PXF_QUEUE       0x01

static void     px_attach(device_t, device_t, void *);
static void     px_init(struct stic_info *, int);
static int      px_ioctl(struct stic_info *, u_long, void *, int,
                         struct lwp *);
static int      px_match(device_t, cfdata_t, void *);

static int      px_intr(void *);
static uint32_t *px_pbuf_get(struct stic_info *);
static int      px_pbuf_post(struct stic_info *, uint32_t *);

void    px_cnattach(tc_addr_t);

struct px_softc {
        device_t px_dev;
        struct  stic_info *px_si;
        volatile uint32_t       *px_qpoll[PX_BUF_COUNT];
};

CFATTACH_DECL_NEW(px, sizeof(struct px_softc),
    px_match, px_attach, NULL, NULL);

static int
px_match(device_t parent, cfdata_t match, void *aux)
{
        struct tc_attach_args *ta;

        ta = aux;

        return (strncmp("PMAG-CA ", ta->ta_modname, TC_ROM_LLEN) == 0);
}

static void
px_attach(device_t parent, device_t self, void *aux)
{
        struct stic_info *si;
        struct tc_attach_args *ta;
        struct px_softc *px;
        int console, i;
        u_long v;

        px = device_private(self);
        ta = aux;

        px->px_dev = self;

        if (ta->ta_addr == stic_consinfo.si_slotbase) {
                si = &stic_consinfo;
                console = 1;
        } else {
                if (stic_consinfo.si_slotbase == 0)
                        si = &stic_consinfo;
                else {
                        si = malloc(sizeof(*si), M_DEVBUF, M_WAITOK | M_ZERO);
                }
                si->si_slotbase = ta->ta_addr;
                px_init(si, 0);
                console = 0;
        }

        px->px_si = si;
        si->si_dv = self;
        tc_intr_establish(parent, ta->ta_cookie, IPL_TTY, px_intr, si);

        printf(": 8 plane, %dx%d stamp\n", si->si_stampw, si->si_stamph);

        for (i = 0; i < PX_BUF_COUNT; i++) {
                v = i * STIC_PACKET_SIZE +
                    si->si_buf_phys + STIC_XCOMM_SIZE;
                v = ((v & 0xffff8000) << 3) | (v & 0x7fff);
                px->px_qpoll[i] = (volatile uint32_t *)
                    ((char *)si->si_slotbase + (v >> 9));
        }

        stic_attach(self, si, console);
}

void
px_cnattach(tc_addr_t addr)
{
        struct stic_info *si;

        si = &stic_consinfo;
        si->si_slotbase = addr;
        px_init(si, 1);
        stic_cnattach(si);
}

static void
px_init(struct stic_info *si, int bootstrap)
{
        struct pglist pglist;
        char *kva, *bva;
        paddr_t bpa;

        kva = (void *)si->si_slotbase;

        /*
         * Allocate memory for the packet buffers.  It must be located below
         * 8MB, since the STIC can't access outside that region.  Also, due
         * to the holes in STIC address space, each buffer mustn't cross a
         * 32kB boundary.
         */
        if (bootstrap) {
                /*
                 * UVM won't be initialised at this point, so grab memory
                 * directly from vm_physmem[].
                 */
                bva = (char *)uvm_pageboot_alloc(PX_BUF_SIZE + PX_BUF_ALIGN);
                bpa = (STIC_KSEG_TO_PHYS(bva) + PX_BUF_ALIGN - 1) &
                    ~(PX_BUF_ALIGN - 1);
                if (bpa + PX_BUF_SIZE > 8192*1024)
                        panic("px_init: allocation out of bounds");
        } else {
                if (uvm_pglistalloc(PX_BUF_SIZE, 0, 8192*1024, PX_BUF_ALIGN,
                    0, &pglist, 1, 0) != 0)
                        panic("px_init: allocation failure");
                bpa = VM_PAGE_TO_PHYS(TAILQ_FIRST(&pglist));
        }

        si->si_vdac = (uint32_t *)(kva + PX_VDAC_OFFSET);
        si->si_vdac_reset = (uint32_t *)(kva + PX_VDAC_RESET_OFFSET);
        si->si_stic = (volatile struct stic_regs *)(kva + PX_STIC_OFFSET);
        si->si_stamp = (uint32_t *)(kva + PX_STAMP_OFFSET);
        si->si_buf = (uint32_t *)TC_PHYS_TO_UNCACHED(bpa);
        si->si_buf_phys = bpa;
        si->si_buf_size = PX_BUF_SIZE;
        si->si_disptype = WSDISPLAY_TYPE_PX;
        si->si_depth = 8;
        si->si_sxc = (volatile struct stic_xcomm *)si->si_buf;

        si->si_pbuf_get = px_pbuf_get;
        si->si_pbuf_post = px_pbuf_post;
        si->si_ioctl = px_ioctl;

        memset(si->si_buf, 0, PX_BUF_SIZE);

        stic_init(si);
}

static int
px_intr(void *cookie)
{
        volatile struct stic_regs *sr;
        volatile struct stic_xcomm *sxc;
        struct stic_info *si;
        struct px_softc *px;
        int state;

        si = cookie;
        px = device_private(si->si_dv);
        sr = si->si_stic;
        state = sr->sr_ipdvint;
        sxc = si->si_sxc;

        /*
         * Vertical-retrace condition.
         *
         * Clear the flag and flush out any waiting VDAC updates.  We do
         * this at retrace time to avoid producing `shearing' and other
         * nasty artifacts.
         */
        if ((state & STIC_INT_V) != 0) {
                sr->sr_ipdvint = STIC_INT_V_WE | STIC_INT_V_EN;
                tc_wmb();
                stic_flush(si);
        }

        /*
         * Error condition.
         *
         * Simply clear the flag and report the error.
         */
        if ((state & STIC_INT_E) != 0) {
                aprint_error_dev(px->px_dev, "error intr, %x %x %x %x %x",
                    sr->sr_ipdvint, sr->sr_sticsr, sr->sr_buscsr,
                    sr->sr_busadr, sr->sr_busdat);
                sr->sr_ipdvint = STIC_INT_E_WE | STIC_INT_E_EN;
                tc_wmb();
        }

        /*
         * Check for queue stalls.
         */
        if (sxc->sxc_tail != sxc->sxc_head && !sxc->sxc_busy)
                state |= STIC_INT_P;

        /*
         * Packet-done condition.
         *
         * If packet queueing is enabled, clear the condition, and increment
         * the tail (submitted) pointer.
         */
        if ((si->si_hwflags & PXF_QUEUE) != 0 && (state & STIC_INT_P) != 0) {
                sr->sr_ipdvint = STIC_INT_P_WE | STIC_INT_P_EN;
                tc_wmb();

                if (sxc->sxc_tail != sxc->sxc_head) {
                        sxc->sxc_done[sxc->sxc_tail] = 0;
                        sxc->sxc_tail = PX_BUF_INC(sxc->sxc_tail);
                }

                if (sxc->sxc_tail != sxc->sxc_head) {
                        if (*px->px_qpoll[sxc->sxc_tail] != STAMP_OK) {
                                sxc->sxc_nreject++;
                                sxc->sxc_busy = 0;
                        } else
                                sxc->sxc_busy = 1;
                } else
                        sxc->sxc_busy = 0;
        }

        if ((si->si_hwflags & PXF_QUEUE) != 0 && (state & STIC_INT_P_EN) == 0)
                printf("px_intr: STIC_INT_P_EN == 0\n");

        return (1);
}

static uint32_t *
px_pbuf_get(struct stic_info *si)
{
        u_long off;

        si->si_pbuf_select ^= STIC_PACKET_SIZE;
        off = si->si_pbuf_select + STIC_XCOMM_SIZE;
        return ((uint32_t *)((char *)si->si_buf + off));
}

static int
px_pbuf_post(struct stic_info *si, uint32_t *buf)
{
        volatile uint32_t *poll, junk;
        volatile struct stic_regs *sr;
        u_long v;
        int c;

        sr = si->si_stic;

        /* Get address of poll register for this buffer. */
        v = (u_long)STIC_KSEG_TO_PHYS(buf);
        v = ((v & 0xffff8000) << 3) | (v & 0x7fff);
        poll = (volatile uint32_t *)((char *)si->si_slotbase + (v >> 9));

        /*
         * Read the poll register and make sure the stamp wants to accept
         * our packet.  This read will initiate the DMA.  Don't wait for
         * ever, just in case something's wrong.
         */
        tc_mb();

        for (c = STAMP_RETRIES; c != 0; c--) {
                if ((sr->sr_ipdvint & STIC_INT_P) != 0) {
                        sr->sr_ipdvint = STIC_INT_P_WE;
                        tc_wmb();
                        junk = *poll;
                        __USE(junk);
                        return (0);
                }
                DELAY(STAMP_DELAY);
        }

        /* STIC has lost the plot, punish it. */
        stic_reset(si);
        return (-1);
}

static int
px_ioctl(struct stic_info *si, u_long cmd, void *data, int flag,
         struct lwp *l)
{
        volatile struct stic_xcomm *sxc;
        volatile struct stic_regs *sr;
        struct stic_xinfo *sxi;
        int rv, s;

        sr = si->si_stic;

        switch (cmd) {
        case STICIO_STARTQ:
                if (si->si_dispmode != WSDISPLAYIO_MODE_MAPPED ||
                    (si->si_hwflags & PXF_QUEUE) != 0) {
                        rv = EBUSY;
                        break;
                }

                sxc = si->si_sxc;
                memset((void *)__UNVOLATILE(sxc->sxc_done), 0,
                        sizeof(sxc->sxc_done));
                sxc->sxc_head = 0;
                sxc->sxc_tail = 0;
                sxc->sxc_nreject = 0;
                sxc->sxc_nstall = 0;

                s = spltty();
                si->si_hwflags |= PXF_QUEUE;
                sr->sr_ipdvint = STIC_INT_P_WE | STIC_INT_P_EN;
                tc_wmb();
                splx(s);

                rv = 0;
                break;

        case STICIO_STOPQ:
                s = spltty();
                si->si_hwflags &= ~PXF_QUEUE;
                sr->sr_ipdvint = STIC_INT_P_WE | STIC_INT_P;
                tc_wmb();
                splx(s);
                rv = 0;
                break;

        case STICIO_GXINFO:
                sxi = (struct stic_xinfo *)data;
                sxi->sxi_unit = si->si_unit;
                sxi->sxi_stampw = si->si_stampw;
                sxi->sxi_stamph = si->si_stamph;
                sxi->sxi_buf_size = si->si_buf_size;
                sxi->sxi_buf_phys = (u_int)si->si_buf_phys;
                sxi->sxi_buf_pktoff = STIC_XCOMM_SIZE;
                sxi->sxi_buf_pktcnt = PX_BUF_COUNT;
                sxi->sxi_buf_imgoff =
                    STIC_XCOMM_SIZE + STIC_PACKET_SIZE * PX_BUF_COUNT;
                rv = 0;
                break;

        default:
                rv = EPASSTHROUGH;
                break;
        }

        return (rv);
}