/*
 * Copyright 2014 Red Hat Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 *
 * Authors: Ben Skeggs
 */
#include "outp.h"
#include "dp.h"
#include "ior.h"

#include <subdev/bios.h>
#include <subdev/bios/dcb.h>
#include <subdev/i2c.h>

void
nvkm_outp_route(struct nvkm_disp *disp)
{
        struct nvkm_outp *outp;
        struct nvkm_ior *ior;

        list_for_each_entry(ior, &disp->ior, head) {
                if ((outp = ior->arm.outp) && ior->arm.outp != ior->asy.outp) {
                        OUTP_DBG(outp, "release %s", ior->name);
                        if (ior->func->route.set)
                                ior->func->route.set(outp, NULL);
                        ior->arm.outp = NULL;
                }
        }

        list_for_each_entry(ior, &disp->ior, head) {
                if ((outp = ior->asy.outp)) {
                        OUTP_DBG(outp, "acquire %s", ior->name);
                        if (ior->asy.outp != ior->arm.outp) {
                                if (ior->func->route.set)
                                        ior->func->route.set(outp, ior);
                                ior->arm.outp = ior->asy.outp;
                        }
                }
        }
}

static enum nvkm_ior_proto
nvkm_outp_xlat(struct nvkm_outp *outp, enum nvkm_ior_type *type)
{
        switch (outp->info.location) {
        case 0:
                switch (outp->info.type) {
                case DCB_OUTPUT_ANALOG: *type = DAC; return  CRT;
                case DCB_OUTPUT_TV    : *type = DAC; return   TV;
                case DCB_OUTPUT_TMDS  : *type = SOR; return TMDS;
                case DCB_OUTPUT_LVDS  : *type = SOR; return LVDS;
                case DCB_OUTPUT_DP    : *type = SOR; return   DP;
                default:
                        break;
                }
                break;
        case 1:
                switch (outp->info.type) {
                case DCB_OUTPUT_TMDS: *type = PIOR; return TMDS;
                case DCB_OUTPUT_DP  : *type = PIOR; return TMDS; /* not a bug */
                default:
                        break;
                }
                break;
        default:
                break;
        }
        WARN_ON(1);
        return UNKNOWN;
}

void
nvkm_outp_release(struct nvkm_outp *outp, u8 user)
{
        struct nvkm_ior *ior = outp->ior;
        OUTP_TRACE(outp, "release %02x &= %02x %p", outp->acquired, ~user, ior);
        if (ior) {
                outp->acquired &= ~user;
                if (!outp->acquired) {
                        if (outp->func->release && outp->ior)
                                outp->func->release(outp);
                        outp->ior->asy.outp = NULL;
                        outp->ior = NULL;
                }
        }
}

static inline int
nvkm_outp_acquire_ior(struct nvkm_outp *outp, u8 user, struct nvkm_ior *ior)
{
        outp->ior = ior;
        outp->ior->asy.outp = outp;
        outp->ior->asy.link = outp->info.sorconf.link;
        outp->acquired |= user;
        return 0;
}

static inline int
nvkm_outp_acquire_hda(struct nvkm_outp *outp, enum nvkm_ior_type type,
                      u8 user, bool hda)
{
        struct nvkm_ior *ior;

        /* Failing that, a completely unused OR is the next best thing. */
        list_for_each_entry(ior, &outp->disp->ior, head) {
                if (!ior->identity && !!ior->func->hda.hpd == hda &&
                    !ior->asy.outp && ior->type == type && !ior->arm.outp &&
                    (ior->func->route.set || ior->id == __ffs(outp->info.or)))
                        return nvkm_outp_acquire_ior(outp, user, ior);
        }

        /* Last resort is to assign an OR that's already active on HW,
         * but will be released during the next modeset.
         */
        list_for_each_entry(ior, &outp->disp->ior, head) {
                if (!ior->identity && !!ior->func->hda.hpd == hda &&
                    !ior->asy.outp && ior->type == type &&
                    (ior->func->route.set || ior->id == __ffs(outp->info.or)))
                        return nvkm_outp_acquire_ior(outp, user, ior);
        }

        return -ENOSPC;
}

int
nvkm_outp_acquire(struct nvkm_outp *outp, u8 user, bool hda)
{
        struct nvkm_ior *ior = outp->ior;
        enum nvkm_ior_proto proto;
        enum nvkm_ior_type type;

        OUTP_TRACE(outp, "acquire %02x |= %02x %p", outp->acquired, user, ior);
        if (ior) {
                outp->acquired |= user;
                return 0;
        }

        /* Lookup a compatible, and unused, OR to assign to the device. */
        proto = nvkm_outp_xlat(outp, &type);
        if (proto == UNKNOWN)
                return -ENOSYS;

        /* Deal with panels requiring identity-mapped SOR assignment. */
        if (outp->identity) {
                ior = nvkm_ior_find(outp->disp, SOR, ffs(outp->info.or) - 1);
                if (WARN_ON(!ior))
                        return -ENOSPC;
                return nvkm_outp_acquire_ior(outp, user, ior);
        }

        /* First preference is to reuse the OR that is currently armed
         * on HW, if any, in order to prevent unnecessary switching.
         */
        list_for_each_entry(ior, &outp->disp->ior, head) {
                if (!ior->identity && !ior->asy.outp && ior->arm.outp == outp) {
                        /*XXX: For various complicated reasons, we can't outright switch
                         *     the boot-time OR on the first modeset without some fairly
                         *     invasive changes.
                         *
                         *     The systems that were fixed by modifying the OR selection
                         *     code to account for HDA support shouldn't regress here as
                         *     the HDA-enabled ORs match the relevant output's pad macro
                         *     index, and the firmware seems to select an OR this way.
                         *
                         *     This warning is to make it obvious if that proves wrong.
                         */
                        WARN_ON(hda && !ior->func->hda.hpd);
                        return nvkm_outp_acquire_ior(outp, user, ior);
                }
        }

        /* If we don't need HDA, first try to acquire an OR that doesn't
         * support it to leave free the ones that do.
         */
        if (!hda) {
                if (!nvkm_outp_acquire_hda(outp, type, user, false))
                        return 0;

                /* Use a HDA-supporting SOR anyway. */
                return nvkm_outp_acquire_hda(outp, type, user, true);
        }

        /* We want HDA, try to acquire an OR that supports it. */
        if (!nvkm_outp_acquire_hda(outp, type, user, true))
                return 0;

        /* There weren't any free ORs that support HDA, grab one that
         * doesn't and at least allow display to work still.
         */
        return nvkm_outp_acquire_hda(outp, type, user, false);
}

void
nvkm_outp_fini(struct nvkm_outp *outp)
{
        if (outp->func->fini)
                outp->func->fini(outp);
}

static void
nvkm_outp_init_route(struct nvkm_outp *outp)
{
        struct nvkm_disp *disp = outp->disp;
        enum nvkm_ior_proto proto;
        enum nvkm_ior_type type;
        struct nvkm_ior *ior;
        int id, link;

        /* Find any OR from the class that is able to support this device. */
        proto = nvkm_outp_xlat(outp, &type);
        if (proto == UNKNOWN)
                return;

        ior = nvkm_ior_find(disp, type, -1);
        if (!ior) {
                WARN_ON(1);
                return;
        }

        /* Determine the specific OR, if any, this device is attached to. */
        if (ior->func->route.get) {
                id = ior->func->route.get(outp, &link);
                if (id < 0) {
                        OUTP_DBG(outp, "no route");
                        return;
                }
        } else {
                /* Prior to DCB 4.1, this is hardwired like so. */
                id   = ffs(outp->info.or) - 1;
                link = (ior->type == SOR) ? outp->info.sorconf.link : 0;
        }

        ior = nvkm_ior_find(disp, type, id);
        if (!ior) {
                WARN_ON(1);
                return;
        }

        /* Determine if the OR is already configured for this device. */
        ior->func->state(ior, &ior->arm);
        if (!ior->arm.head || ior->arm.proto != proto) {
                OUTP_DBG(outp, "no heads (%x %d %d)", ior->arm.head,
                         ior->arm.proto, proto);

                /* The EFI GOP driver on Ampere can leave unused DP links routed,
                 * which we don't expect.  The DisableLT IED script *should* get
                 * us back to where we need to be.
                 */
                if (ior->func->route.get && !ior->arm.head && outp->info.type == DCB_OUTPUT_DP)
                        nvkm_dp_disable(outp, ior);

                return;
        }

        OUTP_DBG(outp, "on %s link %x", ior->name, ior->arm.link);
        ior->arm.outp = outp;
}

void
nvkm_outp_init(struct nvkm_outp *outp)
{
        nvkm_outp_init_route(outp);
        if (outp->func->init)
                outp->func->init(outp);
}

void
nvkm_outp_del(struct nvkm_outp **poutp)
{
        struct nvkm_outp *outp = *poutp;
        if (outp && !WARN_ON(!outp->func)) {
                if (outp->func->dtor)
                        *poutp = outp->func->dtor(outp);
                kfree(*poutp);
                *poutp = NULL;
        }
}

int
nvkm_outp_ctor(const struct nvkm_outp_func *func, struct nvkm_disp *disp,
               int index, struct dcb_output *dcbE, struct nvkm_outp *outp)
{
        struct nvkm_i2c *i2c = disp->engine.subdev.device->i2c;
        enum nvkm_ior_proto proto;
        enum nvkm_ior_type type;

        outp->func = func;
        outp->disp = disp;
        outp->index = index;
        outp->info = *dcbE;
        outp->i2c = nvkm_i2c_bus_find(i2c, dcbE->i2c_index);

        OUTP_DBG(outp, "type %02x loc %d or %d link %d con %x "
                       "edid %x bus %d head %x",
                 outp->info.type, outp->info.location, outp->info.or,
                 outp->info.type >= 2 ? outp->info.sorconf.link : 0,
                 outp->info.connector, outp->info.i2c_index,
                 outp->info.bus, outp->info.heads);

        /* Cull output paths we can't map to an output resource. */
        proto = nvkm_outp_xlat(outp, &type);
        if (proto == UNKNOWN)
                return -ENODEV;

        return 0;
}

static const struct nvkm_outp_func
nvkm_outp = {
};

int
nvkm_outp_new(struct nvkm_disp *disp, int index, struct dcb_output *dcbE,
              struct nvkm_outp **poutp)
{
        if (!(*poutp = kzalloc(sizeof(**poutp), GFP_KERNEL)))
                return -ENOMEM;
        return nvkm_outp_ctor(&nvkm_outp, disp, index, dcbE, *poutp);
}