/*
 * 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 "dp.h"
#include "conn.h"
#include "head.h"
#include "ior.h"

#include <subdev/bios.h>
#include <subdev/bios/init.h>
#include <subdev/gpio.h>
#include <subdev/i2c.h>

#include <nvif/event.h>

/* IED scripts are no longer used by UEFI/RM from Ampere, but have been updated for
 * the x86 option ROM.  However, the relevant VBIOS table versions weren't modified,
 * so we're unable to detect this in a nice way.
 */
#define AMPERE_IED_HACK(disp) ((disp)->engine.subdev.device->card_type >= GA100)

struct lt_state {
        struct nvkm_dp *dp;
        u8  stat[6];
        u8  conf[4];
        bool pc2;
        u8  pc2stat;
        u8  pc2conf[2];
};

static int
nvkm_dp_train_sense(struct lt_state *lt, bool pc, u32 delay)
{
        struct nvkm_dp *dp = lt->dp;
        int ret;

        if (dp->dpcd[DPCD_RC0E_AUX_RD_INTERVAL])
                mdelay(dp->dpcd[DPCD_RC0E_AUX_RD_INTERVAL] * 4);
        else
                udelay(delay);

        ret = nvkm_rdaux(dp->aux, DPCD_LS02, lt->stat, 6);
        if (ret)
                return ret;

        if (pc) {
                ret = nvkm_rdaux(dp->aux, DPCD_LS0C, &lt->pc2stat, 1);
                if (ret)
                        lt->pc2stat = 0x00;
                OUTP_TRACE(&dp->outp, "status %6ph pc2 %02x",
                           lt->stat, lt->pc2stat);
        } else {
                OUTP_TRACE(&dp->outp, "status %6ph", lt->stat);
        }

        return 0;
}

static int
nvkm_dp_train_drive(struct lt_state *lt, bool pc)
{
        struct nvkm_dp *dp = lt->dp;
        struct nvkm_ior *ior = dp->outp.ior;
        struct nvkm_bios *bios = ior->disp->engine.subdev.device->bios;
        struct nvbios_dpout info;
        struct nvbios_dpcfg ocfg;
        u8  ver, hdr, cnt, len;
        u32 data;
        int ret, i;

        for (i = 0; i < ior->dp.nr; i++) {
                u8 lane = (lt->stat[4 + (i >> 1)] >> ((i & 1) * 4)) & 0xf;
                u8 lpc2 = (lt->pc2stat >> (i * 2)) & 0x3;
                u8 lpre = (lane & 0x0c) >> 2;
                u8 lvsw = (lane & 0x03) >> 0;
                u8 hivs = 3 - lpre;
                u8 hipe = 3;
                u8 hipc = 3;

                if (lpc2 >= hipc)
                        lpc2 = hipc | DPCD_LC0F_LANE0_MAX_POST_CURSOR2_REACHED;
                if (lpre >= hipe) {
                        lpre = hipe | DPCD_LC03_MAX_SWING_REACHED; /* yes. */
                        lvsw = hivs = 3 - (lpre & 3);
                } else
                if (lvsw >= hivs) {
                        lvsw = hivs | DPCD_LC03_MAX_SWING_REACHED;
                }

                lt->conf[i] = (lpre << 3) | lvsw;
                lt->pc2conf[i >> 1] |= lpc2 << ((i & 1) * 4);

                OUTP_TRACE(&dp->outp, "config lane %d %02x %02x",
                           i, lt->conf[i], lpc2);

                data = nvbios_dpout_match(bios, dp->outp.info.hasht,
                                                dp->outp.info.hashm,
                                          &ver, &hdr, &cnt, &len, &info);
                if (!data)
                        continue;

                data = nvbios_dpcfg_match(bios, data, lpc2 & 3, lvsw & 3,
                                          lpre & 3, &ver, &hdr, &cnt, &len,
                                          &ocfg);
                if (!data)
                        continue;

                ior->func->dp.drive(ior, i, ocfg.pc, ocfg.dc,
                                            ocfg.pe, ocfg.tx_pu);
        }

        ret = nvkm_wraux(dp->aux, DPCD_LC03(0), lt->conf, 4);
        if (ret)
                return ret;

        if (pc) {
                ret = nvkm_wraux(dp->aux, DPCD_LC0F, lt->pc2conf, 2);
                if (ret)
                        return ret;
        }

        return 0;
}

static void
nvkm_dp_train_pattern(struct lt_state *lt, u8 pattern)
{
        struct nvkm_dp *dp = lt->dp;
        u8 sink_tp;

        OUTP_TRACE(&dp->outp, "training pattern %d", pattern);
        dp->outp.ior->func->dp.pattern(dp->outp.ior, pattern);

        nvkm_rdaux(dp->aux, DPCD_LC02, &sink_tp, 1);
        sink_tp &= ~DPCD_LC02_TRAINING_PATTERN_SET;
        sink_tp |= pattern;
        nvkm_wraux(dp->aux, DPCD_LC02, &sink_tp, 1);
}

static int
nvkm_dp_train_eq(struct lt_state *lt)
{
        bool eq_done = false, cr_done = true;
        int tries = 0, i;

        if (lt->dp->dpcd[DPCD_RC02] & DPCD_RC02_TPS3_SUPPORTED)
                nvkm_dp_train_pattern(lt, 3);
        else
                nvkm_dp_train_pattern(lt, 2);

        do {
                if ((tries &&
                    nvkm_dp_train_drive(lt, lt->pc2)) ||
                    nvkm_dp_train_sense(lt, lt->pc2, 400))
                        break;

                eq_done = !!(lt->stat[2] & DPCD_LS04_INTERLANE_ALIGN_DONE);
                for (i = 0; i < lt->dp->outp.ior->dp.nr && eq_done; i++) {
                        u8 lane = (lt->stat[i >> 1] >> ((i & 1) * 4)) & 0xf;
                        if (!(lane & DPCD_LS02_LANE0_CR_DONE))
                                cr_done = false;
                        if (!(lane & DPCD_LS02_LANE0_CHANNEL_EQ_DONE) ||
                            !(lane & DPCD_LS02_LANE0_SYMBOL_LOCKED))
                                eq_done = false;
                }
        } while (!eq_done && cr_done && ++tries <= 5);

        return eq_done ? 0 : -1;
}

static int
nvkm_dp_train_cr(struct lt_state *lt)
{
        bool cr_done = false, abort = false;
        int voltage = lt->conf[0] & DPCD_LC03_VOLTAGE_SWING_SET;
        int tries = 0, i;

        nvkm_dp_train_pattern(lt, 1);

        do {
                if (nvkm_dp_train_drive(lt, false) ||
                    nvkm_dp_train_sense(lt, false, 100))
                        break;

                cr_done = true;
                for (i = 0; i < lt->dp->outp.ior->dp.nr; i++) {
                        u8 lane = (lt->stat[i >> 1] >> ((i & 1) * 4)) & 0xf;
                        if (!(lane & DPCD_LS02_LANE0_CR_DONE)) {
                                cr_done = false;
                                if (lt->conf[i] & DPCD_LC03_MAX_SWING_REACHED)
                                        abort = true;
                                break;
                        }
                }

                if ((lt->conf[0] & DPCD_LC03_VOLTAGE_SWING_SET) != voltage) {
                        voltage = lt->conf[0] & DPCD_LC03_VOLTAGE_SWING_SET;
                        tries = 0;
                }
        } while (!cr_done && !abort && ++tries < 5);

        return cr_done ? 0 : -1;
}

static int
nvkm_dp_train_links(struct nvkm_dp *dp)
{
        struct nvkm_ior *ior = dp->outp.ior;
        struct nvkm_disp *disp = dp->outp.disp;
        struct nvkm_subdev *subdev = &disp->engine.subdev;
        struct nvkm_bios *bios = subdev->device->bios;
        struct lt_state lt = {
                .dp = dp,
        };
        u32 lnkcmp;
        u8 sink[2];
        int ret;

        OUTP_DBG(&dp->outp, "training %d x %d MB/s",
                 ior->dp.nr, ior->dp.bw * 27);

        /* Intersect misc. capabilities of the OR and sink. */
        if (disp->engine.subdev.device->chipset < 0xd0)
                dp->dpcd[DPCD_RC02] &= ~DPCD_RC02_TPS3_SUPPORTED;
        lt.pc2 = dp->dpcd[DPCD_RC02] & DPCD_RC02_TPS3_SUPPORTED;

        if (AMPERE_IED_HACK(disp) && (lnkcmp = lt.dp->info.script[0])) {
                /* Execute BeforeLinkTraining script from DP Info table. */
                while (ior->dp.bw < nvbios_rd08(bios, lnkcmp))
                        lnkcmp += 3;
                lnkcmp = nvbios_rd16(bios, lnkcmp + 1);

                nvbios_init(&dp->outp.disp->engine.subdev, lnkcmp,
                        init.outp = &dp->outp.info;
                        init.or   = ior->id;
                        init.link = ior->asy.link;
                );
        }

        /* Set desired link configuration on the source. */
        if ((lnkcmp = lt.dp->info.lnkcmp)) {
                if (dp->version < 0x30) {
                        while ((ior->dp.bw * 2700) < nvbios_rd16(bios, lnkcmp))
                                lnkcmp += 4;
                        lnkcmp = nvbios_rd16(bios, lnkcmp + 2);
                } else {
                        while (ior->dp.bw < nvbios_rd08(bios, lnkcmp))
                                lnkcmp += 3;
                        lnkcmp = nvbios_rd16(bios, lnkcmp + 1);
                }

                nvbios_init(subdev, lnkcmp,
                        init.outp = &dp->outp.info;
                        init.or   = ior->id;
                        init.link = ior->asy.link;
                );
        }

        ret = ior->func->dp.links(ior, dp->aux);
        if (ret) {
                if (ret < 0) {
                        OUTP_ERR(&dp->outp, "train failed with %d", ret);
                        return ret;
                }
                return 0;
        }

        ior->func->dp.power(ior, ior->dp.nr);

        /* Set desired link configuration on the sink. */
        sink[0] = ior->dp.bw;
        sink[1] = ior->dp.nr;
        if (ior->dp.ef)
                sink[1] |= DPCD_LC01_ENHANCED_FRAME_EN;

        ret = nvkm_wraux(dp->aux, DPCD_LC00_LINK_BW_SET, sink, 2);
        if (ret)
                return ret;

        /* Attempt to train the link in this configuration. */
        memset(lt.stat, 0x00, sizeof(lt.stat));
        ret = nvkm_dp_train_cr(&lt);
        if (ret == 0)
                ret = nvkm_dp_train_eq(&lt);
        nvkm_dp_train_pattern(&lt, 0);
        return ret;
}

static void
nvkm_dp_train_fini(struct nvkm_dp *dp)
{
        /* Execute AfterLinkTraining script from DP Info table. */
        nvbios_init(&dp->outp.disp->engine.subdev, dp->info.script[1],
                init.outp = &dp->outp.info;
                init.or   = dp->outp.ior->id;
                init.link = dp->outp.ior->asy.link;
        );
}

static void
nvkm_dp_train_init(struct nvkm_dp *dp)
{
        /* Execute EnableSpread/DisableSpread script from DP Info table. */
        if (dp->dpcd[DPCD_RC03] & DPCD_RC03_MAX_DOWNSPREAD) {
                nvbios_init(&dp->outp.disp->engine.subdev, dp->info.script[2],
                        init.outp = &dp->outp.info;
                        init.or   = dp->outp.ior->id;
                        init.link = dp->outp.ior->asy.link;
                );
        } else {
                nvbios_init(&dp->outp.disp->engine.subdev, dp->info.script[3],
                        init.outp = &dp->outp.info;
                        init.or   = dp->outp.ior->id;
                        init.link = dp->outp.ior->asy.link;
                );
        }

        if (!AMPERE_IED_HACK(dp->outp.disp)) {
                /* Execute BeforeLinkTraining script from DP Info table. */
                nvbios_init(&dp->outp.disp->engine.subdev, dp->info.script[0],
                        init.outp = &dp->outp.info;
                        init.or   = dp->outp.ior->id;
                        init.link = dp->outp.ior->asy.link;
                );
        }
}

static const struct dp_rates {
        u32 rate;
        u8  bw;
        u8  nr;
} nvkm_dp_rates[] = {
        { 2160000, 0x14, 4 },
        { 1080000, 0x0a, 4 },
        { 1080000, 0x14, 2 },
        {  648000, 0x06, 4 },
        {  540000, 0x0a, 2 },
        {  540000, 0x14, 1 },
        {  324000, 0x06, 2 },
        {  270000, 0x0a, 1 },
        {  162000, 0x06, 1 },
        {}
};

static int
nvkm_dp_train(struct nvkm_dp *dp, u32 dataKBps)
{
        struct nvkm_ior *ior = dp->outp.ior;
        const u8 sink_nr = dp->dpcd[DPCD_RC02] & DPCD_RC02_MAX_LANE_COUNT;
        const u8 sink_bw = dp->dpcd[DPCD_RC01_MAX_LINK_RATE];
        const u8 outp_nr = dp->outp.info.dpconf.link_nr;
        const u8 outp_bw = dp->outp.info.dpconf.link_bw;
        const struct dp_rates *failsafe = NULL, *cfg;
        int ret = -EINVAL;
        u8  pwr;

        /* Find the lowest configuration of the OR that can support
         * the required link rate.
         *
         * We will refuse to program the OR to lower rates, even if
         * link training fails at higher rates (or even if the sink
         * can't support the rate at all, though the DD is supposed
         * to prevent such situations from happening).
         *
         * Attempting to do so can cause the entire display to hang,
         * and it's better to have a failed modeset than that.
         */
        for (cfg = nvkm_dp_rates; cfg->rate; cfg++) {
                if (cfg->nr <= outp_nr && cfg->bw <= outp_bw) {
                        /* Try to respect sink limits too when selecting
                         * lowest link configuration.
                         */
                        if (!failsafe ||
                            (cfg->nr <= sink_nr && cfg->bw <= sink_bw))
                                failsafe = cfg;
                }

                if (failsafe && cfg[1].rate < dataKBps)
                        break;
        }

        if (WARN_ON(!failsafe))
                return ret;

        /* Ensure sink is not in a low-power state. */
        if (!nvkm_rdaux(dp->aux, DPCD_SC00, &pwr, 1)) {
                if ((pwr & DPCD_SC00_SET_POWER) != DPCD_SC00_SET_POWER_D0) {
                        pwr &= ~DPCD_SC00_SET_POWER;
                        pwr |=  DPCD_SC00_SET_POWER_D0;
                        nvkm_wraux(dp->aux, DPCD_SC00, &pwr, 1);
                }
        }

        /* Link training. */
        OUTP_DBG(&dp->outp, "training (min: %d x %d MB/s)",
                 failsafe->nr, failsafe->bw * 27);
        nvkm_dp_train_init(dp);
        for (cfg = nvkm_dp_rates; ret < 0 && cfg <= failsafe; cfg++) {
                /* Skip configurations not supported by both OR and sink. */
                if ((cfg->nr > outp_nr || cfg->bw > outp_bw ||
                     cfg->nr > sink_nr || cfg->bw > sink_bw)) {
                        if (cfg != failsafe)
                                continue;
                        OUTP_ERR(&dp->outp, "link rate unsupported by sink");
                }
                ior->dp.mst = dp->lt.mst;
                ior->dp.ef = dp->dpcd[DPCD_RC02] & DPCD_RC02_ENHANCED_FRAME_CAP;
                ior->dp.bw = cfg->bw;
                ior->dp.nr = cfg->nr;

                /* Program selected link configuration. */
                ret = nvkm_dp_train_links(dp);
        }
        nvkm_dp_train_fini(dp);
        if (ret < 0)
                OUTP_ERR(&dp->outp, "training failed");
        else
                OUTP_DBG(&dp->outp, "training done");
        atomic_set(&dp->lt.done, 1);
        return ret;
}

void
nvkm_dp_disable(struct nvkm_outp *outp, struct nvkm_ior *ior)
{
        struct nvkm_dp *dp = nvkm_dp(outp);

        /* Execute DisableLT script from DP Info Table. */
        nvbios_init(&ior->disp->engine.subdev, dp->info.script[4],
                init.outp = &dp->outp.info;
                init.or   = ior->id;
                init.link = ior->arm.link;
        );
}

static void
nvkm_dp_release(struct nvkm_outp *outp)
{
        struct nvkm_dp *dp = nvkm_dp(outp);

        /* Prevent link from being retrained if sink sends an IRQ. */
        atomic_set(&dp->lt.done, 0);
        dp->outp.ior->dp.nr = 0;
}

static int
nvkm_dp_acquire(struct nvkm_outp *outp)
{
        struct nvkm_dp *dp = nvkm_dp(outp);
        struct nvkm_ior *ior = dp->outp.ior;
        struct nvkm_head *head;
        bool retrain = true;
        u32 datakbps = 0;
        u32 dataKBps;
        u32 linkKBps;
        u8  stat[3];
        int ret, i;

        mutex_lock(&dp->mutex);

        /* Check that link configuration meets current requirements. */
        list_for_each_entry(head, &outp->disp->head, head) {
                if (ior->asy.head & (1 << head->id)) {
                        u32 khz = (head->asy.hz >> ior->asy.rgdiv) / 1000;
                        datakbps += khz * head->asy.or.depth;
                }
        }

        linkKBps = ior->dp.bw * 27000 * ior->dp.nr;
        dataKBps = DIV_ROUND_UP(datakbps, 8);
        OUTP_DBG(&dp->outp, "data %d KB/s link %d KB/s mst %d->%d",
                 dataKBps, linkKBps, ior->dp.mst, dp->lt.mst);
        if (linkKBps < dataKBps || ior->dp.mst != dp->lt.mst) {
                OUTP_DBG(&dp->outp, "link requirements changed");
                goto done;
        }

        /* Check that link is still trained. */
        ret = nvkm_rdaux(dp->aux, DPCD_LS02, stat, 3);
        if (ret) {
                OUTP_DBG(&dp->outp,
                         "failed to read link status, assuming no sink");
                goto done;
        }

        if (stat[2] & DPCD_LS04_INTERLANE_ALIGN_DONE) {
                for (i = 0; i < ior->dp.nr; i++) {
                        u8 lane = (stat[i >> 1] >> ((i & 1) * 4)) & 0x0f;
                        if (!(lane & DPCD_LS02_LANE0_CR_DONE) ||
                            !(lane & DPCD_LS02_LANE0_CHANNEL_EQ_DONE) ||
                            !(lane & DPCD_LS02_LANE0_SYMBOL_LOCKED)) {
                                OUTP_DBG(&dp->outp,
                                         "lane %d not equalised", lane);
                                goto done;
                        }
                }
                retrain = false;
        } else {
                OUTP_DBG(&dp->outp, "no inter-lane alignment");
        }

done:
        if (retrain || !atomic_read(&dp->lt.done))
                ret = nvkm_dp_train(dp, dataKBps);
        mutex_unlock(&dp->mutex);
        return ret;
}

static bool
nvkm_dp_enable(struct nvkm_dp *dp, bool enable)
{
        struct nvkm_i2c_aux *aux = dp->aux;

        if (enable) {
                if (!dp->present) {
                        OUTP_DBG(&dp->outp, "aux power -> always");
                        nvkm_i2c_aux_monitor(aux, true);
                        dp->present = true;
                }

                if (!nvkm_rdaux(aux, DPCD_RC00_DPCD_REV, dp->dpcd,
                                sizeof(dp->dpcd)))
                        return true;
        }

        if (dp->present) {
                OUTP_DBG(&dp->outp, "aux power -> demand");
                nvkm_i2c_aux_monitor(aux, false);
                dp->present = false;
        }

        atomic_set(&dp->lt.done, 0);
        return false;
}

static int
nvkm_dp_hpd(struct nvkm_notify *notify)
{
        const struct nvkm_i2c_ntfy_rep *line = notify->data;
        struct nvkm_dp *dp = container_of(notify, typeof(*dp), hpd);
        struct nvkm_conn *conn = dp->outp.conn;
        struct nvkm_disp *disp = dp->outp.disp;
        struct nvif_notify_conn_rep_v0 rep = {};

        OUTP_DBG(&dp->outp, "HPD: %d", line->mask);
        if (line->mask & NVKM_I2C_IRQ) {
                if (atomic_read(&dp->lt.done))
                        dp->outp.func->acquire(&dp->outp);
                rep.mask |= NVIF_NOTIFY_CONN_V0_IRQ;
        } else {
                nvkm_dp_enable(dp, true);
        }

        if (line->mask & NVKM_I2C_UNPLUG)
                rep.mask |= NVIF_NOTIFY_CONN_V0_UNPLUG;
        if (line->mask & NVKM_I2C_PLUG)
                rep.mask |= NVIF_NOTIFY_CONN_V0_PLUG;

        nvkm_event_send(&disp->hpd, rep.mask, conn->index, &rep, sizeof(rep));
        return NVKM_NOTIFY_KEEP;
}

static void
nvkm_dp_fini(struct nvkm_outp *outp)
{
        struct nvkm_dp *dp = nvkm_dp(outp);
        nvkm_notify_put(&dp->hpd);
        nvkm_dp_enable(dp, false);
}

static void
nvkm_dp_init(struct nvkm_outp *outp)
{
        struct nvkm_gpio *gpio = outp->disp->engine.subdev.device->gpio;
        struct nvkm_dp *dp = nvkm_dp(outp);

        nvkm_notify_put(&dp->outp.conn->hpd);

        /* eDP panels need powering on by us (if the VBIOS doesn't default it
         * to on) before doing any AUX channel transactions.  LVDS panel power
         * is handled by the SOR itself, and not required for LVDS DDC.
         */
        if (dp->outp.conn->info.type == DCB_CONNECTOR_eDP) {
                int power = nvkm_gpio_get(gpio, 0, DCB_GPIO_PANEL_POWER, 0xff);
                if (power == 0)
                        nvkm_gpio_set(gpio, 0, DCB_GPIO_PANEL_POWER, 0xff, 1);

                /* We delay here unconditionally, even if already powered,
                 * because some laptop panels having a significant resume
                 * delay before the panel begins responding.
                 *
                 * This is likely a bit of a hack, but no better idea for
                 * handling this at the moment.
                 */
                msleep(300);

                /* If the eDP panel can't be detected, we need to restore
                 * the panel power GPIO to avoid breaking another output.
                 */
                if (!nvkm_dp_enable(dp, true) && power == 0)
                        nvkm_gpio_set(gpio, 0, DCB_GPIO_PANEL_POWER, 0xff, 0);
        } else {
                nvkm_dp_enable(dp, true);
        }

        nvkm_notify_get(&dp->hpd);
}

static void *
nvkm_dp_dtor(struct nvkm_outp *outp)
{
        struct nvkm_dp *dp = nvkm_dp(outp);
        nvkm_notify_fini(&dp->hpd);
        return dp;
}

static const struct nvkm_outp_func
nvkm_dp_func = {
        .dtor = nvkm_dp_dtor,
        .init = nvkm_dp_init,
        .fini = nvkm_dp_fini,
        .acquire = nvkm_dp_acquire,
        .release = nvkm_dp_release,
        .disable = nvkm_dp_disable,
};

static int
nvkm_dp_ctor(struct nvkm_disp *disp, int index, struct dcb_output *dcbE,
             struct nvkm_i2c_aux *aux, struct nvkm_dp *dp)
{
        struct nvkm_device *device = disp->engine.subdev.device;
        struct nvkm_bios *bios = device->bios;
        struct nvkm_i2c *i2c = device->i2c;
        u8  hdr, cnt, len;
        u32 data;
        int ret;

        ret = nvkm_outp_ctor(&nvkm_dp_func, disp, index, dcbE, &dp->outp);
        if (ret)
                return ret;

        dp->aux = aux;
        if (!dp->aux) {
                OUTP_ERR(&dp->outp, "no aux");
                return -EINVAL;
        }

        /* bios data is not optional */
        data = nvbios_dpout_match(bios, dp->outp.info.hasht,
                                  dp->outp.info.hashm, &dp->version,
                                  &hdr, &cnt, &len, &dp->info);
        if (!data) {
                OUTP_ERR(&dp->outp, "no bios dp data");
                return -EINVAL;
        }

        OUTP_DBG(&dp->outp, "bios dp %02x %02x %02x %02x",
                 dp->version, hdr, cnt, len);

        /* hotplug detect, replaces gpio-based mechanism with aux events */
        ret = nvkm_notify_init(NULL, &i2c->event, nvkm_dp_hpd, true,
                               &(struct nvkm_i2c_ntfy_req) {
                                .mask = NVKM_I2C_PLUG | NVKM_I2C_UNPLUG |
                                        NVKM_I2C_IRQ,
                                .port = dp->aux->id,
                               },
                               sizeof(struct nvkm_i2c_ntfy_req),
                               sizeof(struct nvkm_i2c_ntfy_rep),
                               &dp->hpd);
        if (ret) {
                OUTP_ERR(&dp->outp, "error monitoring aux hpd: %d", ret);
                return ret;
        }

        mutex_init(&dp->mutex);
        atomic_set(&dp->lt.done, 0);
        return 0;
}

int
nvkm_dp_new(struct nvkm_disp *disp, int index, struct dcb_output *dcbE,
            struct nvkm_outp **poutp)
{
        struct nvkm_i2c *i2c = disp->engine.subdev.device->i2c;
        struct nvkm_i2c_aux *aux;
        struct nvkm_dp *dp;

        if (dcbE->location == 0)
                aux = nvkm_i2c_aux_find(i2c, NVKM_I2C_AUX_CCB(dcbE->i2c_index));
        else
                aux = nvkm_i2c_aux_find(i2c, NVKM_I2C_AUX_EXT(dcbE->extdev));

        if (!(dp = kzalloc(sizeof(*dp), GFP_KERNEL)))
                return -ENOMEM;
        *poutp = &dp->outp;

        return nvkm_dp_ctor(disp, index, dcbE, aux, dp);
}