/*
 * Copyright 2013 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 "priv.h"

#include <subdev/timer.h>

void
nvkm_pmu_pgob(struct nvkm_pmu *pmu, bool enable)
{
        if (pmu && pmu->func->pgob)
                pmu->func->pgob(pmu, enable);
}

int
nvkm_pmu_send(struct nvkm_pmu *pmu, u32 reply[2],
              u32 process, u32 message, u32 data0, u32 data1)
{
        struct nvkm_subdev *subdev = &pmu->subdev;
        struct nvkm_device *device = subdev->device;
        u32 addr;

        /* wait for a free slot in the fifo */
        addr  = nvkm_rd32(device, 0x10a4a0);
        if (nvkm_msec(device, 2000,
                u32 tmp = nvkm_rd32(device, 0x10a4b0);
                if (tmp != (addr ^ 8))
                        break;
        ) < 0)
                return -EBUSY;

        /* we currently only support a single process at a time waiting
         * on a synchronous reply, take the PMU mutex and tell the
         * receive handler what we're waiting for
         */
        if (reply) {
                mutex_lock(&subdev->mutex);
                pmu->recv.message = message;
                pmu->recv.process = process;
        }

        /* acquire data segment access */
        do {
                nvkm_wr32(device, 0x10a580, 0x00000001);
        } while (nvkm_rd32(device, 0x10a580) != 0x00000001);

        /* write the packet */
        nvkm_wr32(device, 0x10a1c0, 0x01000000 | (((addr & 0x07) << 4) +
                                pmu->send.base));
        nvkm_wr32(device, 0x10a1c4, process);
        nvkm_wr32(device, 0x10a1c4, message);
        nvkm_wr32(device, 0x10a1c4, data0);
        nvkm_wr32(device, 0x10a1c4, data1);
        nvkm_wr32(device, 0x10a4a0, (addr + 1) & 0x0f);

        /* release data segment access */
        nvkm_wr32(device, 0x10a580, 0x00000000);

        /* wait for reply, if requested */
        if (reply) {
                wait_event(pmu->recv.wait, (pmu->recv.process == 0));
                reply[0] = pmu->recv.data[0];
                reply[1] = pmu->recv.data[1];
                mutex_unlock(&subdev->mutex);
        }

        return 0;
}

static void
nvkm_pmu_recv(struct work_struct *work)
{
        struct nvkm_pmu *pmu = container_of(work, struct nvkm_pmu, recv.work);
        struct nvkm_subdev *subdev = &pmu->subdev;
        struct nvkm_device *device = subdev->device;
        u32 process, message, data0, data1;

        /* nothing to do if GET == PUT */
        u32 addr =  nvkm_rd32(device, 0x10a4cc);
        if (addr == nvkm_rd32(device, 0x10a4c8))
                return;

        /* acquire data segment access */
        do {
                nvkm_wr32(device, 0x10a580, 0x00000002);
        } while (nvkm_rd32(device, 0x10a580) != 0x00000002);

        /* read the packet */
        nvkm_wr32(device, 0x10a1c0, 0x02000000 | (((addr & 0x07) << 4) +
                                pmu->recv.base));
        process = nvkm_rd32(device, 0x10a1c4);
        message = nvkm_rd32(device, 0x10a1c4);
        data0   = nvkm_rd32(device, 0x10a1c4);
        data1   = nvkm_rd32(device, 0x10a1c4);
        nvkm_wr32(device, 0x10a4cc, (addr + 1) & 0x0f);

        /* release data segment access */
        nvkm_wr32(device, 0x10a580, 0x00000000);

        /* wake process if it's waiting on a synchronous reply */
        if (pmu->recv.process) {
                if (process == pmu->recv.process &&
                    message == pmu->recv.message) {
                        pmu->recv.data[0] = data0;
                        pmu->recv.data[1] = data1;
                        pmu->recv.process = 0;
                        wake_up(&pmu->recv.wait);
                        return;
                }
        }

        /* right now there's no other expected responses from the engine,
         * so assume that any unexpected message is an error.
         */
        nvkm_warn(subdev, "%c%c%c%c %08x %08x %08x %08x\n",
                  (char)((process & 0x000000ff) >>  0),
                  (char)((process & 0x0000ff00) >>  8),
                  (char)((process & 0x00ff0000) >> 16),
                  (char)((process & 0xff000000) >> 24),
                  process, message, data0, data1);
}

static void
nvkm_pmu_intr(struct nvkm_subdev *subdev)
{
        struct nvkm_pmu *pmu = nvkm_pmu(subdev);
        struct nvkm_device *device = pmu->subdev.device;
        u32 disp = nvkm_rd32(device, 0x10a01c);
        u32 intr = nvkm_rd32(device, 0x10a008) & disp & ~(disp >> 16);

        if (intr & 0x00000020) {
                u32 stat = nvkm_rd32(device, 0x10a16c);
                if (stat & 0x80000000) {
                        nvkm_error(subdev, "UAS fault at %06x addr %08x\n",
                                   stat & 0x00ffffff,
                                   nvkm_rd32(device, 0x10a168));
                        nvkm_wr32(device, 0x10a16c, 0x00000000);
                        intr &= ~0x00000020;
                }
        }

        if (intr & 0x00000040) {
                schedule_work(&pmu->recv.work);
                nvkm_wr32(device, 0x10a004, 0x00000040);
                intr &= ~0x00000040;
        }

        if (intr & 0x00000080) {
                nvkm_info(subdev, "wr32 %06x %08x\n",
                          nvkm_rd32(device, 0x10a7a0),
                          nvkm_rd32(device, 0x10a7a4));
                nvkm_wr32(device, 0x10a004, 0x00000080);
                intr &= ~0x00000080;
        }

        if (intr) {
                nvkm_error(subdev, "intr %08x\n", intr);
                nvkm_wr32(device, 0x10a004, intr);
        }
}

static int
nvkm_pmu_fini(struct nvkm_subdev *subdev, bool suspend)
{
        struct nvkm_pmu *pmu = nvkm_pmu(subdev);
        struct nvkm_device *device = pmu->subdev.device;

        nvkm_wr32(device, 0x10a014, 0x00000060);
        flush_work(&pmu->recv.work);
        return 0;
}

static int
nvkm_pmu_init(struct nvkm_subdev *subdev)
{
        struct nvkm_pmu *pmu = nvkm_pmu(subdev);
        struct nvkm_device *device = pmu->subdev.device;
        int i;

        /* prevent previous ucode from running, wait for idle, reset */
        nvkm_wr32(device, 0x10a014, 0x0000ffff); /* INTR_EN_CLR = ALL */
        nvkm_msec(device, 2000,
                if (!nvkm_rd32(device, 0x10a04c))
                        break;
        );
        nvkm_mask(device, 0x000200, 0x00002000, 0x00000000);
        nvkm_mask(device, 0x000200, 0x00002000, 0x00002000);
        nvkm_rd32(device, 0x000200);
        nvkm_msec(device, 2000,
                if (!(nvkm_rd32(device, 0x10a10c) & 0x00000006))
                        break;
        );

        /* upload data segment */
        nvkm_wr32(device, 0x10a1c0, 0x01000000);
        for (i = 0; i < pmu->func->data.size / 4; i++)
                nvkm_wr32(device, 0x10a1c4, pmu->func->data.data[i]);

        /* upload code segment */
        nvkm_wr32(device, 0x10a180, 0x01000000);
        for (i = 0; i < pmu->func->code.size / 4; i++) {
                if ((i & 0x3f) == 0)
                        nvkm_wr32(device, 0x10a188, i >> 6);
                nvkm_wr32(device, 0x10a184, pmu->func->code.data[i]);
        }

        /* start it running */
        nvkm_wr32(device, 0x10a10c, 0x00000000);
        nvkm_wr32(device, 0x10a104, 0x00000000);
        nvkm_wr32(device, 0x10a100, 0x00000002);

        /* wait for valid host->pmu ring configuration */
        if (nvkm_msec(device, 2000,
                if (nvkm_rd32(device, 0x10a4d0))
                        break;
        ) < 0)
                return -EBUSY;
        pmu->send.base = nvkm_rd32(device, 0x10a4d0) & 0x0000ffff;
        pmu->send.size = nvkm_rd32(device, 0x10a4d0) >> 16;

        /* wait for valid pmu->host ring configuration */
        if (nvkm_msec(device, 2000,
                if (nvkm_rd32(device, 0x10a4dc))
                        break;
        ) < 0)
                return -EBUSY;
        pmu->recv.base = nvkm_rd32(device, 0x10a4dc) & 0x0000ffff;
        pmu->recv.size = nvkm_rd32(device, 0x10a4dc) >> 16;

        nvkm_wr32(device, 0x10a010, 0x000000e0);
        return 0;
}

static void *
nvkm_pmu_dtor(struct nvkm_subdev *subdev)
{
        return nvkm_pmu(subdev);
}

static const struct nvkm_subdev_func
nvkm_pmu = {
        .dtor = nvkm_pmu_dtor,
        .init = nvkm_pmu_init,
        .fini = nvkm_pmu_fini,
        .intr = nvkm_pmu_intr,
};

int
nvkm_pmu_new_(const struct nvkm_pmu_func *func, struct nvkm_device *device,
              int index, struct nvkm_pmu **ppmu)
{
        struct nvkm_pmu *pmu;
        if (!(pmu = *ppmu = kzalloc(sizeof(*pmu), GFP_KERNEL)))
                return -ENOMEM;
        nvkm_subdev_ctor(&nvkm_pmu, device, index, 0, &pmu->subdev);
        pmu->func = func;
        INIT_WORK(&pmu->recv.work, nvkm_pmu_recv);
        init_waitqueue_head(&pmu->recv.wait);
        return 0;
}