/*
 * 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/boost.h>
#include <subdev/bios/cstep.h>
#include <subdev/bios/perf.h>
#include <subdev/bios/vpstate.h>
#include <subdev/fb.h>
#include <subdev/therm.h>
#include <subdev/volt.h>

#include <core/option.h>

/******************************************************************************
 * misc
 *****************************************************************************/
static u32
nvkm_clk_adjust(struct nvkm_clk *clk, bool adjust,
                u8 pstate, u8 domain, u32 input)
{
        struct nvkm_bios *bios = clk->subdev.device->bios;
        struct nvbios_boostE boostE;
        u8  ver, hdr, cnt, len;
        u32 data;

        data = nvbios_boostEm(bios, pstate, &ver, &hdr, &cnt, &len, &boostE);
        if (data) {
                struct nvbios_boostS boostS;
                u8  idx = 0, sver, shdr;
                u32 subd;

                input = max(boostE.min, input);
                input = min(boostE.max, input);
                do {
                        sver = ver;
                        shdr = hdr;
                        subd = nvbios_boostSp(bios, idx++, data, &sver, &shdr,
                                              cnt, len, &boostS);
                        if (subd && boostS.domain == domain) {
                                if (adjust)
                                        input = input * boostS.percent / 100;
                                input = max(boostS.min, input);
                                input = min(boostS.max, input);
                                break;
                        }
                } while (subd);
        }

        return input;
}

/******************************************************************************
 * C-States
 *****************************************************************************/
static bool
nvkm_cstate_valid(struct nvkm_clk *clk, struct nvkm_cstate *cstate,
                  u32 max_volt, int temp)
{
        const struct nvkm_domain *domain = clk->domains;
        struct nvkm_volt *volt = clk->subdev.device->volt;
        int voltage;

        while (domain && domain->name != nv_clk_src_max) {
                if (domain->flags & NVKM_CLK_DOM_FLAG_VPSTATE) {
                        u32 freq = cstate->domain[domain->name];
                        switch (clk->boost_mode) {
                        case NVKM_CLK_BOOST_NONE:
                                if (clk->base_khz && freq > clk->base_khz)
                                        return false;
                                fallthrough;
                        case NVKM_CLK_BOOST_BIOS:
                                if (clk->boost_khz && freq > clk->boost_khz)
                                        return false;
                        }
                }
                domain++;
        }

        if (!volt)
                return true;

        voltage = nvkm_volt_map(volt, cstate->voltage, temp);
        if (voltage < 0)
                return false;
        return voltage <= min(max_volt, volt->max_uv);
}

static struct nvkm_cstate *
nvkm_cstate_find_best(struct nvkm_clk *clk, struct nvkm_pstate *pstate,
                      struct nvkm_cstate *cstate)
{
        struct nvkm_device *device = clk->subdev.device;
        struct nvkm_volt *volt = device->volt;
        int max_volt;

        if (!pstate || !cstate)
                return NULL;

        if (!volt)
                return cstate;

        max_volt = volt->max_uv;
        if (volt->max0_id != 0xff)
                max_volt = min(max_volt,
                               nvkm_volt_map(volt, volt->max0_id, clk->temp));
        if (volt->max1_id != 0xff)
                max_volt = min(max_volt,
                               nvkm_volt_map(volt, volt->max1_id, clk->temp));
        if (volt->max2_id != 0xff)
                max_volt = min(max_volt,
                               nvkm_volt_map(volt, volt->max2_id, clk->temp));

        list_for_each_entry_from_reverse(cstate, &pstate->list, head) {
                if (nvkm_cstate_valid(clk, cstate, max_volt, clk->temp))
                        break;
        }

        return cstate;
}

static struct nvkm_cstate *
nvkm_cstate_get(struct nvkm_clk *clk, struct nvkm_pstate *pstate, int cstatei)
{
        struct nvkm_cstate *cstate;
        if (cstatei == NVKM_CLK_CSTATE_HIGHEST)
                return list_last_entry(&pstate->list, typeof(*cstate), head);
        else {
                list_for_each_entry(cstate, &pstate->list, head) {
                        if (cstate->id == cstatei)
                                return cstate;
                }
        }
        return NULL;
}

static int
nvkm_cstate_prog(struct nvkm_clk *clk, struct nvkm_pstate *pstate, int cstatei)
{
        struct nvkm_subdev *subdev = &clk->subdev;
        struct nvkm_device *device = subdev->device;
        struct nvkm_therm *therm = device->therm;
        struct nvkm_volt *volt = device->volt;
        struct nvkm_cstate *cstate;
        int ret;

        if (!list_empty(&pstate->list)) {
                cstate = nvkm_cstate_get(clk, pstate, cstatei);
                cstate = nvkm_cstate_find_best(clk, pstate, cstate);
        } else {
                cstate = &pstate->base;
        }

        if (therm) {
                ret = nvkm_therm_cstate(therm, pstate->fanspeed, +1);
                if (ret && ret != -ENODEV) {
                        nvkm_error(subdev, "failed to raise fan speed: %d\n", ret);
                        return ret;
                }
        }

        if (volt) {
                ret = nvkm_volt_set_id(volt, cstate->voltage,
                                       pstate->base.voltage, clk->temp, +1);
                if (ret && ret != -ENODEV) {
                        nvkm_error(subdev, "failed to raise voltage: %d\n", ret);
                        return ret;
                }
        }

        ret = clk->func->calc(clk, cstate);
        if (ret == 0) {
                ret = clk->func->prog(clk);
                clk->func->tidy(clk);
        }

        if (volt) {
                ret = nvkm_volt_set_id(volt, cstate->voltage,
                                       pstate->base.voltage, clk->temp, -1);
                if (ret && ret != -ENODEV)
                        nvkm_error(subdev, "failed to lower voltage: %d\n", ret);
        }

        if (therm) {
                ret = nvkm_therm_cstate(therm, pstate->fanspeed, -1);
                if (ret && ret != -ENODEV)
                        nvkm_error(subdev, "failed to lower fan speed: %d\n", ret);
        }

        return ret;
}

static void
nvkm_cstate_del(struct nvkm_cstate *cstate)
{
        list_del(&cstate->head);
        kfree(cstate);
}

static int
nvkm_cstate_new(struct nvkm_clk *clk, int idx, struct nvkm_pstate *pstate)
{
        struct nvkm_bios *bios = clk->subdev.device->bios;
        struct nvkm_volt *volt = clk->subdev.device->volt;
        const struct nvkm_domain *domain = clk->domains;
        struct nvkm_cstate *cstate = NULL;
        struct nvbios_cstepX cstepX;
        u8  ver, hdr;
        u32 data;

        data = nvbios_cstepXp(bios, idx, &ver, &hdr, &cstepX);
        if (!data)
                return -ENOENT;

        if (volt && nvkm_volt_map_min(volt, cstepX.voltage) > volt->max_uv)
                return -EINVAL;

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

        *cstate = pstate->base;
        cstate->voltage = cstepX.voltage;
        cstate->id = idx;

        while (domain && domain->name != nv_clk_src_max) {
                if (domain->flags & NVKM_CLK_DOM_FLAG_CORE) {
                        u32 freq = nvkm_clk_adjust(clk, true, pstate->pstate,
                                                   domain->bios, cstepX.freq);
                        cstate->domain[domain->name] = freq;
                }
                domain++;
        }

        list_add(&cstate->head, &pstate->list);
        return 0;
}

/******************************************************************************
 * P-States
 *****************************************************************************/
static int
nvkm_pstate_prog(struct nvkm_clk *clk, int pstatei)
{
        struct nvkm_subdev *subdev = &clk->subdev;
        struct nvkm_fb *fb = subdev->device->fb;
        struct nvkm_pci *pci = subdev->device->pci;
        struct nvkm_pstate *pstate;
        int ret, idx = 0;

        list_for_each_entry(pstate, &clk->states, head) {
                if (idx++ == pstatei)
                        break;
        }

        nvkm_debug(subdev, "setting performance state %d\n", pstatei);
        clk->pstate = pstatei;

        nvkm_pcie_set_link(pci, pstate->pcie_speed, pstate->pcie_width);

        if (fb && fb->ram && fb->ram->func->calc) {
                struct nvkm_ram *ram = fb->ram;
                int khz = pstate->base.domain[nv_clk_src_mem];
                do {
                        ret = ram->func->calc(ram, khz);
                        if (ret == 0)
                                ret = ram->func->prog(ram);
                } while (ret > 0);
                ram->func->tidy(ram);
        }

        return nvkm_cstate_prog(clk, pstate, NVKM_CLK_CSTATE_HIGHEST);
}

static void
nvkm_pstate_work(struct work_struct *work)
{
        struct nvkm_clk *clk = container_of(work, typeof(*clk), work);
        struct nvkm_subdev *subdev = &clk->subdev;
        int pstate;

        if (!atomic_xchg(&clk->waiting, 0))
                return;
        clk->pwrsrc = power_supply_is_system_supplied();

        nvkm_trace(subdev, "P %d PWR %d U(AC) %d U(DC) %d A %d T %d°C D %d\n",
                   clk->pstate, clk->pwrsrc, clk->ustate_ac, clk->ustate_dc,
                   clk->astate, clk->temp, clk->dstate);

        pstate = clk->pwrsrc ? clk->ustate_ac : clk->ustate_dc;
        if (clk->state_nr && pstate != -1) {
                pstate = (pstate < 0) ? clk->astate : pstate;
                pstate = min(pstate, clk->state_nr - 1);
                pstate = max(pstate, clk->dstate);
        } else {
                pstate = clk->pstate = -1;
        }

        nvkm_trace(subdev, "-> %d\n", pstate);
        if (pstate != clk->pstate) {
                int ret = nvkm_pstate_prog(clk, pstate);
                if (ret) {
                        nvkm_error(subdev, "error setting pstate %d: %d\n",
                                   pstate, ret);
                }
        }

        wake_up_all(&clk->wait);
        nvkm_notify_get(&clk->pwrsrc_ntfy);
}

static int
nvkm_pstate_calc(struct nvkm_clk *clk, bool wait)
{
        atomic_set(&clk->waiting, 1);
        schedule_work(&clk->work);
        if (wait)
                wait_event(clk->wait, !atomic_read(&clk->waiting));
        return 0;
}

static void
nvkm_pstate_info(struct nvkm_clk *clk, struct nvkm_pstate *pstate)
{
        const struct nvkm_domain *clock = clk->domains - 1;
        struct nvkm_cstate *cstate;
        struct nvkm_subdev *subdev = &clk->subdev;
        char info[3][32] = { "", "", "" };
        char name[4] = "--";
        int i = -1;

        if (pstate->pstate != 0xff)
                snprintf(name, sizeof(name), "%02x", pstate->pstate);

        while ((++clock)->name != nv_clk_src_max) {
                u32 lo = pstate->base.domain[clock->name];
                u32 hi = lo;
                if (hi == 0)
                        continue;

                nvkm_debug(subdev, "%02x: %10d KHz\n", clock->name, lo);
                list_for_each_entry(cstate, &pstate->list, head) {
                        u32 freq = cstate->domain[clock->name];
                        lo = min(lo, freq);
                        hi = max(hi, freq);
                        nvkm_debug(subdev, "%10d KHz\n", freq);
                }

                if (clock->mname && ++i < ARRAY_SIZE(info)) {
                        lo /= clock->mdiv;
                        hi /= clock->mdiv;
                        if (lo == hi) {
                                snprintf(info[i], sizeof(info[i]), "%s %d MHz",
                                         clock->mname, lo);
                        } else {
                                snprintf(info[i], sizeof(info[i]),
                                         "%s %d-%d MHz", clock->mname, lo, hi);
                        }
                }
        }

        nvkm_debug(subdev, "%s: %s %s %s\n", name, info[0], info[1], info[2]);
}

static void
nvkm_pstate_del(struct nvkm_pstate *pstate)
{
        struct nvkm_cstate *cstate, *temp;

        list_for_each_entry_safe(cstate, temp, &pstate->list, head) {
                nvkm_cstate_del(cstate);
        }

        list_del(&pstate->head);
        kfree(pstate);
}

static int
nvkm_pstate_new(struct nvkm_clk *clk, int idx)
{
        struct nvkm_bios *bios = clk->subdev.device->bios;
        const struct nvkm_domain *domain = clk->domains - 1;
        struct nvkm_pstate *pstate;
        struct nvkm_cstate *cstate;
        struct nvbios_cstepE cstepE;
        struct nvbios_perfE perfE;
        u8  ver, hdr, cnt, len;
        u32 data;

        data = nvbios_perfEp(bios, idx, &ver, &hdr, &cnt, &len, &perfE);
        if (!data)
                return -EINVAL;
        if (perfE.pstate == 0xff)
                return 0;

        pstate = kzalloc(sizeof(*pstate), GFP_KERNEL);
        cstate = &pstate->base;
        if (!pstate)
                return -ENOMEM;

        INIT_LIST_HEAD(&pstate->list);

        pstate->pstate = perfE.pstate;
        pstate->fanspeed = perfE.fanspeed;
        pstate->pcie_speed = perfE.pcie_speed;
        pstate->pcie_width = perfE.pcie_width;
        cstate->voltage = perfE.voltage;
        cstate->domain[nv_clk_src_core] = perfE.core;
        cstate->domain[nv_clk_src_shader] = perfE.shader;
        cstate->domain[nv_clk_src_mem] = perfE.memory;
        cstate->domain[nv_clk_src_vdec] = perfE.vdec;
        cstate->domain[nv_clk_src_dom6] = perfE.disp;

        while (ver >= 0x40 && (++domain)->name != nv_clk_src_max) {
                struct nvbios_perfS perfS;
                u8  sver = ver, shdr = hdr;
                u32 perfSe = nvbios_perfSp(bios, data, domain->bios,
                                          &sver, &shdr, cnt, len, &perfS);
                if (perfSe == 0 || sver != 0x40)
                        continue;

                if (domain->flags & NVKM_CLK_DOM_FLAG_CORE) {
                        perfS.v40.freq = nvkm_clk_adjust(clk, false,
                                                         pstate->pstate,
                                                         domain->bios,
                                                         perfS.v40.freq);
                }

                cstate->domain[domain->name] = perfS.v40.freq;
        }

        data = nvbios_cstepEm(bios, pstate->pstate, &ver, &hdr, &cstepE);
        if (data) {
                int idx = cstepE.index;
                do {
                        nvkm_cstate_new(clk, idx, pstate);
                } while(idx--);
        }

        nvkm_pstate_info(clk, pstate);
        list_add_tail(&pstate->head, &clk->states);
        clk->state_nr++;
        return 0;
}

/******************************************************************************
 * Adjustment triggers
 *****************************************************************************/
static int
nvkm_clk_ustate_update(struct nvkm_clk *clk, int req)
{
        struct nvkm_pstate *pstate;
        int i = 0;

        if (!clk->allow_reclock)
                return -ENOSYS;

        if (req != -1 && req != -2) {
                list_for_each_entry(pstate, &clk->states, head) {
                        if (pstate->pstate == req)
                                break;
                        i++;
                }

                if (pstate->pstate != req)
                        return -EINVAL;
                req = i;
        }

        return req + 2;
}

static int
nvkm_clk_nstate(struct nvkm_clk *clk, const char *mode, int arglen)
{
        int ret = 1;

        if (clk->allow_reclock && !strncasecmpz(mode, "auto", arglen))
                return -2;

        if (strncasecmpz(mode, "disabled", arglen)) {
                char save = mode[arglen];
                long v;

                ((char *)mode)[arglen] = '\0';
                if (!kstrtol(mode, 0, &v)) {
                        ret = nvkm_clk_ustate_update(clk, v);
                        if (ret < 0)
                                ret = 1;
                }
                ((char *)mode)[arglen] = save;
        }

        return ret - 2;
}

int
nvkm_clk_ustate(struct nvkm_clk *clk, int req, int pwr)
{
        int ret = nvkm_clk_ustate_update(clk, req);
        if (ret >= 0) {
                if (ret -= 2, pwr) clk->ustate_ac = ret;
                else               clk->ustate_dc = ret;
                return nvkm_pstate_calc(clk, true);
        }
        return ret;
}

int
nvkm_clk_astate(struct nvkm_clk *clk, int req, int rel, bool wait)
{
        if (!rel) clk->astate  = req;
        if ( rel) clk->astate += rel;
        clk->astate = min(clk->astate, clk->state_nr - 1);
        clk->astate = max(clk->astate, 0);
        return nvkm_pstate_calc(clk, wait);
}

int
nvkm_clk_tstate(struct nvkm_clk *clk, u8 temp)
{
        if (clk->temp == temp)
                return 0;
        clk->temp = temp;
        return nvkm_pstate_calc(clk, false);
}

int
nvkm_clk_dstate(struct nvkm_clk *clk, int req, int rel)
{
        if (!rel) clk->dstate  = req;
        if ( rel) clk->dstate += rel;
        clk->dstate = min(clk->dstate, clk->state_nr - 1);
        clk->dstate = max(clk->dstate, 0);
        return nvkm_pstate_calc(clk, true);
}

static int
nvkm_clk_pwrsrc(struct nvkm_notify *notify)
{
        struct nvkm_clk *clk =
                container_of(notify, typeof(*clk), pwrsrc_ntfy);
        nvkm_pstate_calc(clk, false);
        return NVKM_NOTIFY_DROP;
}

/******************************************************************************
 * subdev base class implementation
 *****************************************************************************/

int
nvkm_clk_read(struct nvkm_clk *clk, enum nv_clk_src src)
{
        return clk->func->read(clk, src);
}

static int
nvkm_clk_fini(struct nvkm_subdev *subdev, bool suspend)
{
        struct nvkm_clk *clk = nvkm_clk(subdev);
        nvkm_notify_put(&clk->pwrsrc_ntfy);
        flush_work(&clk->work);
        if (clk->func->fini)
                clk->func->fini(clk);
        return 0;
}

static int
nvkm_clk_init(struct nvkm_subdev *subdev)
{
        struct nvkm_clk *clk = nvkm_clk(subdev);
        const struct nvkm_domain *clock = clk->domains;
        int ret;

        memset(&clk->bstate, 0x00, sizeof(clk->bstate));
        INIT_LIST_HEAD(&clk->bstate.list);
        clk->bstate.pstate = 0xff;

        while (clock->name != nv_clk_src_max) {
                ret = nvkm_clk_read(clk, clock->name);
                if (ret < 0) {
                        nvkm_error(subdev, "%02x freq unknown\n", clock->name);
                        return ret;
                }
                clk->bstate.base.domain[clock->name] = ret;
                clock++;
        }

        nvkm_pstate_info(clk, &clk->bstate);

        if (clk->func->init)
                return clk->func->init(clk);

        clk->astate = clk->state_nr - 1;
        clk->dstate = 0;
        clk->pstate = -1;
        clk->temp = 90; /* reasonable default value */
        nvkm_pstate_calc(clk, true);
        return 0;
}

static void *
nvkm_clk_dtor(struct nvkm_subdev *subdev)
{
        struct nvkm_clk *clk = nvkm_clk(subdev);
        struct nvkm_pstate *pstate, *temp;

        nvkm_notify_fini(&clk->pwrsrc_ntfy);

        /* Early return if the pstates have been provided statically */
        if (clk->func->pstates)
                return clk;

        list_for_each_entry_safe(pstate, temp, &clk->states, head) {
                nvkm_pstate_del(pstate);
        }

        return clk;
}

static const struct nvkm_subdev_func
nvkm_clk = {
        .dtor = nvkm_clk_dtor,
        .init = nvkm_clk_init,
        .fini = nvkm_clk_fini,
};

int
nvkm_clk_ctor(const struct nvkm_clk_func *func, struct nvkm_device *device,
              enum nvkm_subdev_type type, int inst, bool allow_reclock, struct nvkm_clk *clk)
{
        struct nvkm_subdev *subdev = &clk->subdev;
        struct nvkm_bios *bios = device->bios;
        int ret, idx, arglen;
        const char *mode;
        struct nvbios_vpstate_header h;

        nvkm_subdev_ctor(&nvkm_clk, device, type, inst, subdev);

        if (bios && !nvbios_vpstate_parse(bios, &h)) {
                struct nvbios_vpstate_entry base, boost;
                if (!nvbios_vpstate_entry(bios, &h, h.boost_id, &boost))
                        clk->boost_khz = boost.clock_mhz * 1000;
                if (!nvbios_vpstate_entry(bios, &h, h.base_id, &base))
                        clk->base_khz = base.clock_mhz * 1000;
        }

        clk->func = func;
        INIT_LIST_HEAD(&clk->states);
        clk->domains = func->domains;
        clk->ustate_ac = -1;
        clk->ustate_dc = -1;
        clk->allow_reclock = allow_reclock;

        INIT_WORK(&clk->work, nvkm_pstate_work);
        init_waitqueue_head(&clk->wait);
        atomic_set(&clk->waiting, 0);

        /* If no pstates are provided, try and fetch them from the BIOS */
        if (!func->pstates) {
                idx = 0;
                do {
                        ret = nvkm_pstate_new(clk, idx++);
                } while (ret == 0);
        } else {
                for (idx = 0; idx < func->nr_pstates; idx++)
                        list_add_tail(&func->pstates[idx].head, &clk->states);
                clk->state_nr = func->nr_pstates;
        }

        ret = nvkm_notify_init(NULL, &device->event, nvkm_clk_pwrsrc, true,
                               NULL, 0, 0, &clk->pwrsrc_ntfy);
        if (ret)
                return ret;

        mode = nvkm_stropt(device->cfgopt, "NvClkMode", &arglen);
        if (mode) {
                clk->ustate_ac = nvkm_clk_nstate(clk, mode, arglen);
                clk->ustate_dc = nvkm_clk_nstate(clk, mode, arglen);
        }

        mode = nvkm_stropt(device->cfgopt, "NvClkModeAC", &arglen);
        if (mode)
                clk->ustate_ac = nvkm_clk_nstate(clk, mode, arglen);

        mode = nvkm_stropt(device->cfgopt, "NvClkModeDC", &arglen);
        if (mode)
                clk->ustate_dc = nvkm_clk_nstate(clk, mode, arglen);

        clk->boost_mode = nvkm_longopt(device->cfgopt, "NvBoost",
                                       NVKM_CLK_BOOST_NONE);
        return 0;
}

int
nvkm_clk_new_(const struct nvkm_clk_func *func, struct nvkm_device *device,
              enum nvkm_subdev_type type, int inst, bool allow_reclock, struct nvkm_clk **pclk)
{
        if (!(*pclk = kzalloc(sizeof(**pclk), GFP_KERNEL)))
                return -ENOMEM;
        return nvkm_clk_ctor(func, device, type, inst, allow_reclock, *pclk);
}