/*
 * Copyright 2011 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 "mxms.h"

#include <core/option.h>
#include <subdev/bios.h>
#include <subdev/bios/mxm.h>
#include <subdev/i2c.h>

static bool
mxm_shadow_rom_fetch(struct nvkm_i2c_bus *bus, u8 addr,
                     u8 offset, u8 size, u8 *data)
{
        struct i2c_msg msgs[] = {
                { .addr = addr, .flags = 0, .len = 1, .buf = &offset },
                { .addr = addr, .flags = I2C_M_RD, .len = size, .buf = data, },
        };

        return i2c_transfer(&bus->i2c, msgs, 2) == 2;
}

static bool
mxm_shadow_rom(struct nvkm_mxm *mxm, u8 version)
{
        struct nvkm_device *device = mxm->subdev.device;
        struct nvkm_bios *bios = device->bios;
        struct nvkm_i2c *i2c = device->i2c;
        struct nvkm_i2c_bus *bus = NULL;
        u8 i2cidx, mxms[6], addr, size;

        i2cidx = mxm_ddc_map(bios, 1 /* LVDS_DDC */) & 0x0f;
        if (i2cidx < 0x0f)
                bus = nvkm_i2c_bus_find(i2c, i2cidx);
        if (!bus)
                return false;

        addr = 0x54;
        if (!mxm_shadow_rom_fetch(bus, addr, 0, 6, mxms)) {
                addr = 0x56;
                if (!mxm_shadow_rom_fetch(bus, addr, 0, 6, mxms))
                        return false;
        }

        mxm->mxms = mxms;
        size = mxms_headerlen(mxm) + mxms_structlen(mxm);
        mxm->mxms = kmalloc(size, GFP_KERNEL);

        if (mxm->mxms &&
            mxm_shadow_rom_fetch(bus, addr, 0, size, mxm->mxms))
                return true;

        kfree(mxm->mxms);
        mxm->mxms = NULL;
        return false;
}

#if defined(CONFIG_ACPI)
static bool
mxm_shadow_dsm(struct nvkm_mxm *mxm, u8 version)
{
        struct nvkm_subdev *subdev = &mxm->subdev;
        struct nvkm_device *device = subdev->device;
        static guid_t muid =
                GUID_INIT(0x4004A400, 0x917D, 0x4CF2,
                          0xB8, 0x9C, 0x79, 0xB6, 0x2F, 0xD5, 0x56, 0x65);
        u32 mxms_args[] = { 0x00000000 };
        union acpi_object argv4 = {
                .buffer.type = ACPI_TYPE_BUFFER,
                .buffer.length = sizeof(mxms_args),
                .buffer.pointer = (char *)mxms_args,
        };
        union acpi_object *obj;
        acpi_handle handle;
        int rev;

        handle = ACPI_HANDLE(device->dev);
        if (!handle)
                return false;

        /*
         * spec says this can be zero to mean "highest revision", but
         * of course there's at least one bios out there which fails
         * unless you pass in exactly the version it supports..
         */
        rev = (version & 0xf0) << 4 | (version & 0x0f);
        obj = acpi_evaluate_dsm(handle, &muid, rev, 0x00000010, &argv4);
        if (!obj) {
                nvkm_debug(subdev, "DSM MXMS failed\n");
                return false;
        }

        if (obj->type == ACPI_TYPE_BUFFER) {
                mxm->mxms = kmemdup(obj->buffer.pointer,
                                         obj->buffer.length, GFP_KERNEL);
        } else if (obj->type == ACPI_TYPE_INTEGER) {
                nvkm_debug(subdev, "DSM MXMS returned 0x%llx\n",
                           obj->integer.value);
        }

        ACPI_FREE(obj);
        return mxm->mxms != NULL;
}
#endif

#if defined(CONFIG_ACPI_WMI) || defined(CONFIG_ACPI_WMI_MODULE)

#define WMI_WMMX_GUID "F6CB5C3C-9CAE-4EBD-B577-931EA32A2CC0"

static u8
wmi_wmmx_mxmi(struct nvkm_mxm *mxm, u8 version)
{
        struct nvkm_subdev *subdev = &mxm->subdev;
        u32 mxmi_args[] = { 0x494D584D /* MXMI */, version, 0 };
        struct acpi_buffer args = { sizeof(mxmi_args), mxmi_args };
        struct acpi_buffer retn = { ACPI_ALLOCATE_BUFFER, NULL };
        union acpi_object *obj;
        acpi_status status;

        status = wmi_evaluate_method(WMI_WMMX_GUID, 0, 0, &args, &retn);
        if (ACPI_FAILURE(status)) {
                nvkm_debug(subdev, "WMMX MXMI returned %d\n", status);
                return 0x00;
        }

        obj = retn.pointer;
        if (obj->type == ACPI_TYPE_INTEGER) {
                version = obj->integer.value;
                nvkm_debug(subdev, "WMMX MXMI version %d.%d\n",
                           (version >> 4), version & 0x0f);
        } else {
                version = 0;
                nvkm_debug(subdev, "WMMX MXMI returned non-integer\n");
        }

        kfree(obj);
        return version;
}

static bool
mxm_shadow_wmi(struct nvkm_mxm *mxm, u8 version)
{
        struct nvkm_subdev *subdev = &mxm->subdev;
        u32 mxms_args[] = { 0x534D584D /* MXMS */, version, 0 };
        struct acpi_buffer args = { sizeof(mxms_args), mxms_args };
        struct acpi_buffer retn = { ACPI_ALLOCATE_BUFFER, NULL };
        union acpi_object *obj;
        acpi_status status;

        if (!wmi_has_guid(WMI_WMMX_GUID)) {
                nvkm_debug(subdev, "WMMX GUID not found\n");
                return false;
        }

        mxms_args[1] = wmi_wmmx_mxmi(mxm, 0x00);
        if (!mxms_args[1])
                mxms_args[1] = wmi_wmmx_mxmi(mxm, version);
        if (!mxms_args[1])
                return false;

        status = wmi_evaluate_method(WMI_WMMX_GUID, 0, 0, &args, &retn);
        if (ACPI_FAILURE(status)) {
                nvkm_debug(subdev, "WMMX MXMS returned %d\n", status);
                return false;
        }

        obj = retn.pointer;
        if (obj->type == ACPI_TYPE_BUFFER) {
                mxm->mxms = kmemdup(obj->buffer.pointer,
                                    obj->buffer.length, GFP_KERNEL);
        }

        kfree(obj);
        return mxm->mxms != NULL;
}
#endif

static struct mxm_shadow_h {
        const char *name;
        bool (*exec)(struct nvkm_mxm *, u8 version);
} _mxm_shadow[] = {
        { "ROM", mxm_shadow_rom },
#if defined(CONFIG_ACPI)
        { "DSM", mxm_shadow_dsm },
#endif
#if defined(CONFIG_ACPI_WMI) || defined(CONFIG_ACPI_WMI_MODULE)
        { "WMI", mxm_shadow_wmi },
#endif
        {}
};

static int
mxm_shadow(struct nvkm_mxm *mxm, u8 version)
{
        struct mxm_shadow_h *shadow = _mxm_shadow;
        do {
                nvkm_debug(&mxm->subdev, "checking %s\n", shadow->name);
                if (shadow->exec(mxm, version)) {
                        if (mxms_valid(mxm))
                                return 0;
                        kfree(mxm->mxms);
                        mxm->mxms = NULL;
                }
        } while ((++shadow)->name);
        return -ENOENT;
}

static const struct nvkm_subdev_func
nvkm_mxm = {
};

int
nvkm_mxm_new_(struct nvkm_device *device, enum nvkm_subdev_type type, int inst,
              struct nvkm_mxm **pmxm)
{
        struct nvkm_bios *bios = device->bios;
        struct nvkm_mxm *mxm;
        u8  ver, len;
        u16 data;

        if (!(mxm = *pmxm = kzalloc(sizeof(*mxm), GFP_KERNEL)))
                return -ENOMEM;

        nvkm_subdev_ctor(&nvkm_mxm, device, type, inst, &mxm->subdev);

        data = mxm_table(bios, &ver, &len);
        if (!data || !(ver = nvbios_rd08(bios, data))) {
                nvkm_debug(&mxm->subdev, "no VBIOS data, nothing to do\n");
                return 0;
        }

        nvkm_info(&mxm->subdev, "BIOS version %d.%d\n", ver >> 4, ver & 0x0f);
        nvkm_debug(&mxm->subdev, "module flags: %02x\n",
                   nvbios_rd08(bios, data + 0x01));
        nvkm_debug(&mxm->subdev, "config flags: %02x\n",
                   nvbios_rd08(bios, data + 0x02));

        if (mxm_shadow(mxm, ver)) {
                nvkm_warn(&mxm->subdev, "failed to locate valid SIS\n");
#if 0
                /* we should, perhaps, fall back to some kind of limited
                 * mode here if the x86 vbios hasn't already done the
                 * work for us (so we prevent loading with completely
                 * whacked vbios tables).
                 */
                return -EINVAL;
#else
                return 0;
#endif
        }

        nvkm_debug(&mxm->subdev, "MXMS Version %d.%d\n",
                   mxms_version(mxm) >> 8, mxms_version(mxm) & 0xff);
        mxms_foreach(mxm, 0, NULL, NULL);

        if (nvkm_boolopt(device->cfgopt, "NvMXMDCB", true))
                mxm->action |= MXM_SANITISE_DCB;
        return 0;
}