/*
 * Copyright 2012 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
 */
#define gf100_clk(p) container_of((p), struct gf100_clk, base)
#include "priv.h"
#include "pll.h"

#include <subdev/bios.h>
#include <subdev/bios/pll.h>
#include <subdev/timer.h>

struct gf100_clk_info {
        u32 freq;
        u32 ssel;
        u32 mdiv;
        u32 dsrc;
        u32 ddiv;
        u32 coef;
};

struct gf100_clk {
        struct nvkm_clk base;
        struct gf100_clk_info eng[16];
};

static u32 read_div(struct gf100_clk *, int, u32, u32);

static u32
read_vco(struct gf100_clk *clk, u32 dsrc)
{
        struct nvkm_device *device = clk->base.subdev.device;
        u32 ssrc = nvkm_rd32(device, dsrc);
        if (!(ssrc & 0x00000100))
                return nvkm_clk_read(&clk->base, nv_clk_src_sppll0);
        return nvkm_clk_read(&clk->base, nv_clk_src_sppll1);
}

static u32
read_pll(struct gf100_clk *clk, u32 pll)
{
        struct nvkm_device *device = clk->base.subdev.device;
        u32 ctrl = nvkm_rd32(device, pll + 0x00);
        u32 coef = nvkm_rd32(device, pll + 0x04);
        u32 P = (coef & 0x003f0000) >> 16;
        u32 N = (coef & 0x0000ff00) >> 8;
        u32 M = (coef & 0x000000ff) >> 0;
        u32 sclk;

        if (!(ctrl & 0x00000001))
                return 0;

        switch (pll) {
        case 0x00e800:
        case 0x00e820:
                sclk = device->crystal;
                P = 1;
                break;
        case 0x132000:
                sclk = nvkm_clk_read(&clk->base, nv_clk_src_mpllsrc);
                break;
        case 0x132020:
                sclk = nvkm_clk_read(&clk->base, nv_clk_src_mpllsrcref);
                break;
        case 0x137000:
        case 0x137020:
        case 0x137040:
        case 0x1370e0:
                sclk = read_div(clk, (pll & 0xff) / 0x20, 0x137120, 0x137140);
                break;
        default:
                return 0;
        }

        return sclk * N / M / P;
}

static u32
read_div(struct gf100_clk *clk, int doff, u32 dsrc, u32 dctl)
{
        struct nvkm_device *device = clk->base.subdev.device;
        u32 ssrc = nvkm_rd32(device, dsrc + (doff * 4));
        u32 sctl = nvkm_rd32(device, dctl + (doff * 4));

        switch (ssrc & 0x00000003) {
        case 0:
                if ((ssrc & 0x00030000) != 0x00030000)
                        return device->crystal;
                return 108000;
        case 2:
                return 100000;
        case 3:
                if (sctl & 0x80000000) {
                        u32 sclk = read_vco(clk, dsrc + (doff * 4));
                        u32 sdiv = (sctl & 0x0000003f) + 2;
                        return (sclk * 2) / sdiv;
                }

                return read_vco(clk, dsrc + (doff * 4));
        default:
                return 0;
        }
}

static u32
read_clk(struct gf100_clk *clk, int idx)
{
        struct nvkm_device *device = clk->base.subdev.device;
        u32 sctl = nvkm_rd32(device, 0x137250 + (idx * 4));
        u32 ssel = nvkm_rd32(device, 0x137100);
        u32 sclk, sdiv;

        if (ssel & (1 << idx)) {
                if (idx < 7)
                        sclk = read_pll(clk, 0x137000 + (idx * 0x20));
                else
                        sclk = read_pll(clk, 0x1370e0);
                sdiv = ((sctl & 0x00003f00) >> 8) + 2;
        } else {
                sclk = read_div(clk, idx, 0x137160, 0x1371d0);
                sdiv = ((sctl & 0x0000003f) >> 0) + 2;
        }

        if (sctl & 0x80000000)
                return (sclk * 2) / sdiv;

        return sclk;
}

static int
gf100_clk_read(struct nvkm_clk *base, enum nv_clk_src src)
{
        struct gf100_clk *clk = gf100_clk(base);
        struct nvkm_subdev *subdev = &clk->base.subdev;
        struct nvkm_device *device = subdev->device;

        switch (src) {
        case nv_clk_src_crystal:
                return device->crystal;
        case nv_clk_src_href:
                return 100000;
        case nv_clk_src_sppll0:
                return read_pll(clk, 0x00e800);
        case nv_clk_src_sppll1:
                return read_pll(clk, 0x00e820);

        case nv_clk_src_mpllsrcref:
                return read_div(clk, 0, 0x137320, 0x137330);
        case nv_clk_src_mpllsrc:
                return read_pll(clk, 0x132020);
        case nv_clk_src_mpll:
                return read_pll(clk, 0x132000);
        case nv_clk_src_mdiv:
                return read_div(clk, 0, 0x137300, 0x137310);
        case nv_clk_src_mem:
                if (nvkm_rd32(device, 0x1373f0) & 0x00000002)
                        return nvkm_clk_read(&clk->base, nv_clk_src_mpll);
                return nvkm_clk_read(&clk->base, nv_clk_src_mdiv);

        case nv_clk_src_gpc:
                return read_clk(clk, 0x00);
        case nv_clk_src_rop:
                return read_clk(clk, 0x01);
        case nv_clk_src_hubk07:
                return read_clk(clk, 0x02);
        case nv_clk_src_hubk06:
                return read_clk(clk, 0x07);
        case nv_clk_src_hubk01:
                return read_clk(clk, 0x08);
        case nv_clk_src_copy:
                return read_clk(clk, 0x09);
        case nv_clk_src_pmu:
                return read_clk(clk, 0x0c);
        case nv_clk_src_vdec:
                return read_clk(clk, 0x0e);
        default:
                nvkm_error(subdev, "invalid clock source %d\n", src);
                return -EINVAL;
        }
}

static u32
calc_div(struct gf100_clk *clk, int idx, u32 ref, u32 freq, u32 *ddiv)
{
        u32 div = min((ref * 2) / freq, (u32)65);
        if (div < 2)
                div = 2;

        *ddiv = div - 2;
        return (ref * 2) / div;
}

static u32
calc_src(struct gf100_clk *clk, int idx, u32 freq, u32 *dsrc, u32 *ddiv)
{
        u32 sclk;

        /* use one of the fixed frequencies if possible */
        *ddiv = 0x00000000;
        switch (freq) {
        case  27000:
        case 108000:
                *dsrc = 0x00000000;
                if (freq == 108000)
                        *dsrc |= 0x00030000;
                return freq;
        case 100000:
                *dsrc = 0x00000002;
                return freq;
        default:
                *dsrc = 0x00000003;
                break;
        }

        /* otherwise, calculate the closest divider */
        sclk = read_vco(clk, 0x137160 + (idx * 4));
        if (idx < 7)
                sclk = calc_div(clk, idx, sclk, freq, ddiv);
        return sclk;
}

static u32
calc_pll(struct gf100_clk *clk, int idx, u32 freq, u32 *coef)
{
        struct nvkm_subdev *subdev = &clk->base.subdev;
        struct nvkm_bios *bios = subdev->device->bios;
        struct nvbios_pll limits;
        int N, M, P, ret;

        ret = nvbios_pll_parse(bios, 0x137000 + (idx * 0x20), &limits);
        if (ret)
                return 0;

        limits.refclk = read_div(clk, idx, 0x137120, 0x137140);
        if (!limits.refclk)
                return 0;

        ret = gt215_pll_calc(subdev, &limits, freq, &N, NULL, &M, &P);
        if (ret <= 0)
                return 0;

        *coef = (P << 16) | (N << 8) | M;
        return ret;
}

static int
calc_clk(struct gf100_clk *clk, struct nvkm_cstate *cstate, int idx, int dom)
{
        struct gf100_clk_info *info = &clk->eng[idx];
        u32 freq = cstate->domain[dom];
        u32 src0, div0, div1D, div1P = 0;
        u32 clk0, clk1 = 0;

        /* invalid clock domain */
        if (!freq)
                return 0;

        /* first possible path, using only dividers */
        clk0 = calc_src(clk, idx, freq, &src0, &div0);
        clk0 = calc_div(clk, idx, clk0, freq, &div1D);

        /* see if we can get any closer using PLLs */
        if (clk0 != freq && (0x00004387 & (1 << idx))) {
                if (idx <= 7)
                        clk1 = calc_pll(clk, idx, freq, &info->coef);
                else
                        clk1 = cstate->domain[nv_clk_src_hubk06];
                clk1 = calc_div(clk, idx, clk1, freq, &div1P);
        }

        /* select the method which gets closest to target freq */
        if (abs((int)freq - clk0) <= abs((int)freq - clk1)) {
                info->dsrc = src0;
                if (div0) {
                        info->ddiv |= 0x80000000;
                        info->ddiv |= div0 << 8;
                        info->ddiv |= div0;
                }
                if (div1D) {
                        info->mdiv |= 0x80000000;
                        info->mdiv |= div1D;
                }
                info->ssel = info->coef = 0;
                info->freq = clk0;
        } else {
                if (div1P) {
                        info->mdiv |= 0x80000000;
                        info->mdiv |= div1P << 8;
                }
                info->ssel = (1 << idx);
                info->freq = clk1;
        }

        return 0;
}

static int
gf100_clk_calc(struct nvkm_clk *base, struct nvkm_cstate *cstate)
{
        struct gf100_clk *clk = gf100_clk(base);
        int ret;

        if ((ret = calc_clk(clk, cstate, 0x00, nv_clk_src_gpc)) ||
            (ret = calc_clk(clk, cstate, 0x01, nv_clk_src_rop)) ||
            (ret = calc_clk(clk, cstate, 0x02, nv_clk_src_hubk07)) ||
            (ret = calc_clk(clk, cstate, 0x07, nv_clk_src_hubk06)) ||
            (ret = calc_clk(clk, cstate, 0x08, nv_clk_src_hubk01)) ||
            (ret = calc_clk(clk, cstate, 0x09, nv_clk_src_copy)) ||
            (ret = calc_clk(clk, cstate, 0x0c, nv_clk_src_pmu)) ||
            (ret = calc_clk(clk, cstate, 0x0e, nv_clk_src_vdec)))
                return ret;

        return 0;
}

static void
gf100_clk_prog_0(struct gf100_clk *clk, int idx)
{
        struct gf100_clk_info *info = &clk->eng[idx];
        struct nvkm_device *device = clk->base.subdev.device;
        if (idx < 7 && !info->ssel) {
                nvkm_mask(device, 0x1371d0 + (idx * 0x04), 0x80003f3f, info->ddiv);
                nvkm_wr32(device, 0x137160 + (idx * 0x04), info->dsrc);
        }
}

static void
gf100_clk_prog_1(struct gf100_clk *clk, int idx)
{
        struct nvkm_device *device = clk->base.subdev.device;
        nvkm_mask(device, 0x137100, (1 << idx), 0x00000000);
        nvkm_msec(device, 2000,
                if (!(nvkm_rd32(device, 0x137100) & (1 << idx)))
                        break;
        );
}

static void
gf100_clk_prog_2(struct gf100_clk *clk, int idx)
{
        struct gf100_clk_info *info = &clk->eng[idx];
        struct nvkm_device *device = clk->base.subdev.device;
        const u32 addr = 0x137000 + (idx * 0x20);
        if (idx <= 7) {
                nvkm_mask(device, addr + 0x00, 0x00000004, 0x00000000);
                nvkm_mask(device, addr + 0x00, 0x00000001, 0x00000000);
                if (info->coef) {
                        nvkm_wr32(device, addr + 0x04, info->coef);
                        nvkm_mask(device, addr + 0x00, 0x00000001, 0x00000001);
                        nvkm_msec(device, 2000,
                                if (nvkm_rd32(device, addr + 0x00) & 0x00020000)
                                        break;
                        );
                        nvkm_mask(device, addr + 0x00, 0x00020004, 0x00000004);
                }
        }
}

static void
gf100_clk_prog_3(struct gf100_clk *clk, int idx)
{
        struct gf100_clk_info *info = &clk->eng[idx];
        struct nvkm_device *device = clk->base.subdev.device;
        if (info->ssel) {
                nvkm_mask(device, 0x137100, (1 << idx), info->ssel);
                nvkm_msec(device, 2000,
                        u32 tmp = nvkm_rd32(device, 0x137100) & (1 << idx);
                        if (tmp == info->ssel)
                                break;
                );
        }
}

static void
gf100_clk_prog_4(struct gf100_clk *clk, int idx)
{
        struct gf100_clk_info *info = &clk->eng[idx];
        struct nvkm_device *device = clk->base.subdev.device;
        nvkm_mask(device, 0x137250 + (idx * 0x04), 0x00003f3f, info->mdiv);
}

static int
gf100_clk_prog(struct nvkm_clk *base)
{
        struct gf100_clk *clk = gf100_clk(base);
        struct {
                void (*exec)(struct gf100_clk *, int);
        } stage[] = {
                { gf100_clk_prog_0 }, /* div programming */
                { gf100_clk_prog_1 }, /* select div mode */
                { gf100_clk_prog_2 }, /* (maybe) program pll */
                { gf100_clk_prog_3 }, /* (maybe) select pll mode */
                { gf100_clk_prog_4 }, /* final divider */
        };
        int i, j;

        for (i = 0; i < ARRAY_SIZE(stage); i++) {
                for (j = 0; j < ARRAY_SIZE(clk->eng); j++) {
                        if (!clk->eng[j].freq)
                                continue;
                        stage[i].exec(clk, j);
                }
        }

        return 0;
}

static void
gf100_clk_tidy(struct nvkm_clk *base)
{
        struct gf100_clk *clk = gf100_clk(base);
        memset(clk->eng, 0x00, sizeof(clk->eng));
}

static const struct nvkm_clk_func
gf100_clk = {
        .read = gf100_clk_read,
        .calc = gf100_clk_calc,
        .prog = gf100_clk_prog,
        .tidy = gf100_clk_tidy,
        .domains = {
                { nv_clk_src_crystal, 0xff },
                { nv_clk_src_href   , 0xff },
                { nv_clk_src_hubk06 , 0x00 },
                { nv_clk_src_hubk01 , 0x01 },
                { nv_clk_src_copy   , 0x02 },
                { nv_clk_src_gpc    , 0x03, 0, "core", 2000 },
                { nv_clk_src_rop    , 0x04 },
                { nv_clk_src_mem    , 0x05, 0, "memory", 1000 },
                { nv_clk_src_vdec   , 0x06 },
                { nv_clk_src_pmu    , 0x0a },
                { nv_clk_src_hubk07 , 0x0b },
                { nv_clk_src_max }
        }
};

int
gf100_clk_new(struct nvkm_device *device, int index, struct nvkm_clk **pclk)
{
        struct gf100_clk *clk;

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

        return nvkm_clk_ctor(&gf100_clk, device, index, false, &clk->base);
}