/*
 * Copyright 2015 Karol Herbst <nouveau@karolherbst.de>
 *
 * 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: Karol Herbst <nouveau@karolherbst.de>
 */
#include "priv.h"

static int
gk104_pcie_version_supported(struct nvkm_pci *pci)
{
        return (nvkm_rd32(pci->subdev.device, 0x8c1c0) & 0x4) == 0x4 ? 2 : 1;
}

static void
gk104_pcie_set_cap_speed(struct nvkm_pci *pci, enum nvkm_pcie_speed speed)
{
        struct nvkm_device *device = pci->subdev.device;

        switch (speed) {
        case NVKM_PCIE_SPEED_2_5:
                gf100_pcie_set_cap_speed(pci, false);
                nvkm_mask(device, 0x8c1c0, 0x30000, 0x10000);
                break;
        case NVKM_PCIE_SPEED_5_0:
                gf100_pcie_set_cap_speed(pci, true);
                nvkm_mask(device, 0x8c1c0, 0x30000, 0x20000);
                break;
        case NVKM_PCIE_SPEED_8_0:
                gf100_pcie_set_cap_speed(pci, true);
                nvkm_mask(device, 0x8c1c0, 0x30000, 0x30000);
                break;
        }
}

static enum nvkm_pcie_speed
gk104_pcie_cap_speed(struct nvkm_pci *pci)
{
        int speed = gf100_pcie_cap_speed(pci);

        if (speed == 0)
                return NVKM_PCIE_SPEED_2_5;

        if (speed >= 1) {
                int speed2 = nvkm_rd32(pci->subdev.device, 0x8c1c0) & 0x30000;
                switch (speed2) {
                case 0x00000:
                case 0x10000:
                        return NVKM_PCIE_SPEED_2_5;
                case 0x20000:
                        return NVKM_PCIE_SPEED_5_0;
                case 0x30000:
                        return NVKM_PCIE_SPEED_8_0;
                }
        }

        return -EINVAL;
}

static void
gk104_pcie_set_lnkctl_speed(struct nvkm_pci *pci, enum nvkm_pcie_speed speed)
{
        u8 reg_v = 0;
        switch (speed) {
        case NVKM_PCIE_SPEED_2_5:
                reg_v = 1;
                break;
        case NVKM_PCIE_SPEED_5_0:
                reg_v = 2;
                break;
        case NVKM_PCIE_SPEED_8_0:
                reg_v = 3;
                break;
        }
        nvkm_pci_mask(pci, 0xa8, 0x3, reg_v);
}

static enum nvkm_pcie_speed
gk104_pcie_lnkctl_speed(struct nvkm_pci *pci)
{
        u8 reg_v = nvkm_pci_rd32(pci, 0xa8) & 0x3;
        switch (reg_v) {
        case 0:
        case 1:
                return NVKM_PCIE_SPEED_2_5;
        case 2:
                return NVKM_PCIE_SPEED_5_0;
        case 3:
                return NVKM_PCIE_SPEED_8_0;
        }
        return -1;
}

static enum nvkm_pcie_speed
gk104_pcie_max_speed(struct nvkm_pci *pci)
{
        u32 max_speed = nvkm_rd32(pci->subdev.device, 0x8c1c0) & 0x300000;
        switch (max_speed) {
        case 0x000000:
                return NVKM_PCIE_SPEED_8_0;
        case 0x100000:
                return NVKM_PCIE_SPEED_5_0;
        case 0x200000:
                return NVKM_PCIE_SPEED_2_5;
        }
        return NVKM_PCIE_SPEED_2_5;
}

static void
gk104_pcie_set_link_speed(struct nvkm_pci *pci, enum nvkm_pcie_speed speed)
{
        struct nvkm_device *device = pci->subdev.device;
        u32 mask_value;

        switch (speed) {
        case NVKM_PCIE_SPEED_8_0:
                mask_value = 0x00000;
                break;
        case NVKM_PCIE_SPEED_5_0:
                mask_value = 0x40000;
                break;
        case NVKM_PCIE_SPEED_2_5:
        default:
                mask_value = 0x80000;
                break;
        }

        nvkm_mask(device, 0x8c040, 0xc0000, mask_value);
        nvkm_mask(device, 0x8c040, 0x1, 0x1);
}

static int
gk104_pcie_init(struct nvkm_pci * pci)
{
        enum nvkm_pcie_speed lnkctl_speed, max_speed, cap_speed;
        struct nvkm_subdev *subdev = &pci->subdev;

        if (gf100_pcie_version(pci) < 2)
                return 0;

        lnkctl_speed = gk104_pcie_lnkctl_speed(pci);
        max_speed = gk104_pcie_max_speed(pci);
        cap_speed = gk104_pcie_cap_speed(pci);

        if (cap_speed != max_speed) {
                nvkm_trace(subdev, "adjusting cap to max speed\n");
                gk104_pcie_set_cap_speed(pci, max_speed);
                cap_speed = gk104_pcie_cap_speed(pci);
                if (cap_speed != max_speed)
                        nvkm_warn(subdev, "failed to adjust cap speed\n");
        }

        if (lnkctl_speed != max_speed) {
                nvkm_debug(subdev, "adjusting lnkctl to max speed\n");
                gk104_pcie_set_lnkctl_speed(pci, max_speed);
                lnkctl_speed = gk104_pcie_lnkctl_speed(pci);
                if (lnkctl_speed != max_speed)
                        nvkm_error(subdev, "failed to adjust lnkctl speed\n");
        }

        return 0;
}

static int
gk104_pcie_set_link(struct nvkm_pci *pci, enum nvkm_pcie_speed speed, u8 width)
{
        struct nvkm_subdev *subdev = &pci->subdev;
        enum nvkm_pcie_speed lnk_ctl_speed = gk104_pcie_lnkctl_speed(pci);
        enum nvkm_pcie_speed lnk_cap_speed = gk104_pcie_cap_speed(pci);

        if (speed > lnk_cap_speed) {
                speed = lnk_cap_speed;
                nvkm_warn(subdev, "dropping requested speed due too low cap"
                          " speed\n");
        }

        if (speed > lnk_ctl_speed) {
                speed = lnk_ctl_speed;
                nvkm_warn(subdev, "dropping requested speed due too low"
                          " lnkctl speed\n");
        }

        gk104_pcie_set_link_speed(pci, speed);
        return 0;
}


static const struct nvkm_pci_func
gk104_pci_func = {
        .cfg = { .addr = 0x088000, .size = 0x1000 },

        .init = g84_pci_init,
        .msi_rearm = nv40_pci_msi_rearm,

        .pcie.init = gk104_pcie_init,
        .pcie.set_link = gk104_pcie_set_link,

        .pcie.max_speed = gk104_pcie_max_speed,
        .pcie.cur_speed = g84_pcie_cur_speed,

        .pcie.set_version = gf100_pcie_set_version,
        .pcie.version = gf100_pcie_version,
        .pcie.version_supported = gk104_pcie_version_supported,
};

int
gk104_pci_new(struct nvkm_device *device, enum nvkm_subdev_type type, int inst,
              struct nvkm_pci **ppci)
{
        return nvkm_pci_new_(&gk104_pci_func, device, type, inst, ppci);
}