/*
 * 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/bios.h>
#include <subdev/bios/vmap.h>
#include <subdev/bios/volt.h>

int
nvkm_volt_get(struct nvkm_volt *volt)
{
        int ret, i;

        if (volt->func->volt_get)
                return volt->func->volt_get(volt);

        ret = volt->func->vid_get(volt);
        if (ret >= 0) {
                for (i = 0; i < volt->vid_nr; i++) {
                        if (volt->vid[i].vid == ret)
                                return volt->vid[i].uv;
                }
                ret = -EINVAL;
        }
        return ret;
}

static int
nvkm_volt_set(struct nvkm_volt *volt, u32 uv)
{
        struct nvkm_subdev *subdev = &volt->subdev;
        int i, ret = -EINVAL;

        if (volt->func->volt_set)
                return volt->func->volt_set(volt, uv);

        for (i = 0; i < volt->vid_nr; i++) {
                if (volt->vid[i].uv == uv) {
                        ret = volt->func->vid_set(volt, volt->vid[i].vid);
                        nvkm_debug(subdev, "set %duv: %d\n", uv, ret);
                        break;
                }
        }
        return ret;
}

static int
nvkm_volt_map(struct nvkm_volt *volt, u8 id)
{
        struct nvkm_bios *bios = volt->subdev.device->bios;
        struct nvbios_vmap_entry info;
        u8  ver, len;
        u16 vmap;

        vmap = nvbios_vmap_entry_parse(bios, id, &ver, &len, &info);
        if (vmap) {
                if (info.link != 0xff) {
                        int ret = nvkm_volt_map(volt, info.link);
                        if (ret < 0)
                                return ret;
                        info.min += ret;
                }
                return info.min;
        }

        return id ? id * 10000 : -ENODEV;
}

int
nvkm_volt_set_id(struct nvkm_volt *volt, u8 id, int condition)
{
        int ret;

        if (volt->func->set_id)
                return volt->func->set_id(volt, id, condition);

        ret = nvkm_volt_map(volt, id);
        if (ret >= 0) {
                int prev = nvkm_volt_get(volt);
                if (!condition || prev < 0 ||
                    (condition < 0 && ret < prev) ||
                    (condition > 0 && ret > prev)) {
                        ret = nvkm_volt_set(volt, ret);
                } else {
                        ret = 0;
                }
        }
        return ret;
}

static void
nvkm_volt_parse_bios(struct nvkm_bios *bios, struct nvkm_volt *volt)
{
        struct nvbios_volt_entry ivid;
        struct nvbios_volt info;
        u8  ver, hdr, cnt, len;
        u16 data;
        int i;

        data = nvbios_volt_parse(bios, &ver, &hdr, &cnt, &len, &info);
        if (data && info.vidmask && info.base && info.step) {
                for (i = 0; i < info.vidmask + 1; i++) {
                        if (info.base >= info.min &&
                                info.base <= info.max) {
                                volt->vid[volt->vid_nr].uv = info.base;
                                volt->vid[volt->vid_nr].vid = i;
                                volt->vid_nr++;
                        }
                        info.base += info.step;
                }
                volt->vid_mask = info.vidmask;
        } else if (data && info.vidmask) {
                for (i = 0; i < cnt; i++) {
                        data = nvbios_volt_entry_parse(bios, i, &ver, &hdr,
                                                       &ivid);
                        if (data) {
                                volt->vid[volt->vid_nr].uv = ivid.voltage;
                                volt->vid[volt->vid_nr].vid = ivid.vid;
                                volt->vid_nr++;
                        }
                }
                volt->vid_mask = info.vidmask;
        }
}

static int
nvkm_volt_init(struct nvkm_subdev *subdev)
{
        struct nvkm_volt *volt = nvkm_volt(subdev);
        int ret = nvkm_volt_get(volt);
        if (ret < 0) {
                if (ret != -ENODEV)
                        nvkm_debug(subdev, "current voltage unknown\n");
                return 0;
        }
        nvkm_debug(subdev, "current voltage: %duv\n", ret);
        return 0;
}

static void *
nvkm_volt_dtor(struct nvkm_subdev *subdev)
{
        return nvkm_volt(subdev);
}

static const struct nvkm_subdev_func
nvkm_volt = {
        .dtor = nvkm_volt_dtor,
        .init = nvkm_volt_init,
};

void
nvkm_volt_ctor(const struct nvkm_volt_func *func, struct nvkm_device *device,
               int index, struct nvkm_volt *volt)
{
        struct nvkm_bios *bios = device->bios;
        int i;

        nvkm_subdev_ctor(&nvkm_volt, device, index, &volt->subdev);
        volt->func = func;

        /* Assuming the non-bios device should build the voltage table later */
        if (bios)
                nvkm_volt_parse_bios(bios, volt);

        if (volt->vid_nr) {
                for (i = 0; i < volt->vid_nr; i++) {
                        nvkm_debug(&volt->subdev, "VID %02x: %duv\n",
                                   volt->vid[i].vid, volt->vid[i].uv);
                }
        }
}

int
nvkm_volt_new_(const struct nvkm_volt_func *func, struct nvkm_device *device,
               int index, struct nvkm_volt **pvolt)
{
        if (!(*pvolt = kzalloc(sizeof(**pvolt), GFP_KERNEL)))
                return -ENOMEM;
        nvkm_volt_ctor(func, device, index, *pvolt);
        return 0;
}