/*
 * 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 mcp77_clk(p) container_of((p), struct mcp77_clk, base)
#include "gt215.h"
#include "pll.h"

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

struct mcp77_clk {
        struct nvkm_clk base;
        enum nv_clk_src csrc, ssrc, vsrc;
        u32 cctrl, sctrl;
        u32 ccoef, scoef;
        u32 cpost, spost;
        u32 vdiv;
};

static u32
read_div(struct mcp77_clk *clk)
{
        struct nvkm_device *device = clk->base.subdev.device;
        return nvkm_rd32(device, 0x004600);
}

static u32
read_pll(struct mcp77_clk *clk, u32 base)
{
        struct nvkm_device *device = clk->base.subdev.device;
        u32 ctrl = nvkm_rd32(device, base + 0);
        u32 coef = nvkm_rd32(device, base + 4);
        u32 ref = nvkm_clk_read(&clk->base, nv_clk_src_href);
        u32 post_div = 0;
        u32 clock = 0;
        int N1, M1;

        switch (base){
        case 0x4020:
                post_div = 1 << ((nvkm_rd32(device, 0x4070) & 0x000f0000) >> 16);
                break;
        case 0x4028:
                post_div = (nvkm_rd32(device, 0x4040) & 0x000f0000) >> 16;
                break;
        default:
                break;
        }

        N1 = (coef & 0x0000ff00) >> 8;
        M1 = (coef & 0x000000ff);
        if ((ctrl & 0x80000000) && M1) {
                clock = ref * N1 / M1;
                clock = clock / post_div;
        }

        return clock;
}

static int
mcp77_clk_read(struct nvkm_clk *base, enum nv_clk_src src)
{
        struct mcp77_clk *clk = mcp77_clk(base);
        struct nvkm_subdev *subdev = &clk->base.subdev;
        struct nvkm_device *device = subdev->device;
        u32 mast = nvkm_rd32(device, 0x00c054);
        u32 P = 0;

        switch (src) {
        case nv_clk_src_crystal:
                return device->crystal;
        case nv_clk_src_href:
                return 100000; /* PCIE reference clock */
        case nv_clk_src_hclkm4:
                return nvkm_clk_read(&clk->base, nv_clk_src_href) * 4;
        case nv_clk_src_hclkm2d3:
                return nvkm_clk_read(&clk->base, nv_clk_src_href) * 2 / 3;
        case nv_clk_src_host:
                switch (mast & 0x000c0000) {
                case 0x00000000: return nvkm_clk_read(&clk->base, nv_clk_src_hclkm2d3);
                case 0x00040000: break;
                case 0x00080000: return nvkm_clk_read(&clk->base, nv_clk_src_hclkm4);
                case 0x000c0000: return nvkm_clk_read(&clk->base, nv_clk_src_cclk);
                }
                break;
        case nv_clk_src_core:
                P = (nvkm_rd32(device, 0x004028) & 0x00070000) >> 16;

                switch (mast & 0x00000003) {
                case 0x00000000: return nvkm_clk_read(&clk->base, nv_clk_src_crystal) >> P;
                case 0x00000001: return 0;
                case 0x00000002: return nvkm_clk_read(&clk->base, nv_clk_src_hclkm4) >> P;
                case 0x00000003: return read_pll(clk, 0x004028) >> P;
                }
                break;
        case nv_clk_src_cclk:
                if ((mast & 0x03000000) != 0x03000000)
                        return nvkm_clk_read(&clk->base, nv_clk_src_core);

                if ((mast & 0x00000200) == 0x00000000)
                        return nvkm_clk_read(&clk->base, nv_clk_src_core);

                switch (mast & 0x00000c00) {
                case 0x00000000: return nvkm_clk_read(&clk->base, nv_clk_src_href);
                case 0x00000400: return nvkm_clk_read(&clk->base, nv_clk_src_hclkm4);
                case 0x00000800: return nvkm_clk_read(&clk->base, nv_clk_src_hclkm2d3);
                default: return 0;
                }
        case nv_clk_src_shader:
                P = (nvkm_rd32(device, 0x004020) & 0x00070000) >> 16;
                switch (mast & 0x00000030) {
                case 0x00000000:
                        if (mast & 0x00000040)
                                return nvkm_clk_read(&clk->base, nv_clk_src_href) >> P;
                        return nvkm_clk_read(&clk->base, nv_clk_src_crystal) >> P;
                case 0x00000010: break;
                case 0x00000020: return read_pll(clk, 0x004028) >> P;
                case 0x00000030: return read_pll(clk, 0x004020) >> P;
                }
                break;
        case nv_clk_src_mem:
                return 0;
        case nv_clk_src_vdec:
                P = (read_div(clk) & 0x00000700) >> 8;

                switch (mast & 0x00400000) {
                case 0x00400000:
                        return nvkm_clk_read(&clk->base, nv_clk_src_core) >> P;
                default:
                        return 500000 >> P;
                }
                break;
        default:
                break;
        }

        nvkm_debug(subdev, "unknown clock source %d %08x\n", src, mast);
        return 0;
}

static u32
calc_pll(struct mcp77_clk *clk, u32 reg,
         u32 clock, int *N, int *M, int *P)
{
        struct nvkm_subdev *subdev = &clk->base.subdev;
        struct nvbios_pll pll;
        int ret;

        ret = nvbios_pll_parse(subdev->device->bios, reg, &pll);
        if (ret)
                return 0;

        pll.vco2.max_freq = 0;
        pll.refclk = nvkm_clk_read(&clk->base, nv_clk_src_href);
        if (!pll.refclk)
                return 0;

        return nv04_pll_calc(subdev, &pll, clock, N, M, NULL, NULL, P);
}

static inline u32
calc_P(u32 src, u32 target, int *div)
{
        u32 clk0 = src, clk1 = src;
        for (*div = 0; *div <= 7; (*div)++) {
                if (clk0 <= target) {
                        clk1 = clk0 << (*div ? 1 : 0);
                        break;
                }
                clk0 >>= 1;
        }

        if (target - clk0 <= clk1 - target)
                return clk0;
        (*div)--;
        return clk1;
}

static int
mcp77_clk_calc(struct nvkm_clk *base, struct nvkm_cstate *cstate)
{
        struct mcp77_clk *clk = mcp77_clk(base);
        const int shader = cstate->domain[nv_clk_src_shader];
        const int core = cstate->domain[nv_clk_src_core];
        const int vdec = cstate->domain[nv_clk_src_vdec];
        struct nvkm_subdev *subdev = &clk->base.subdev;
        u32 out = 0, clock = 0;
        int N, M, P1, P2 = 0;
        int divs = 0;

        /* cclk: find suitable source, disable PLL if we can */
        if (core < nvkm_clk_read(&clk->base, nv_clk_src_hclkm4))
                out = calc_P(nvkm_clk_read(&clk->base, nv_clk_src_hclkm4), core, &divs);

        /* Calculate clock * 2, so shader clock can use it too */
        clock = calc_pll(clk, 0x4028, (core << 1), &N, &M, &P1);

        if (abs(core - out) <= abs(core - (clock >> 1))) {
                clk->csrc = nv_clk_src_hclkm4;
                clk->cctrl = divs << 16;
        } else {
                /* NVCTRL is actually used _after_ NVPOST, and after what we
                 * call NVPLL. To make matters worse, NVPOST is an integer
                 * divider instead of a right-shift number. */
                if(P1 > 2) {
                        P2 = P1 - 2;
                        P1 = 2;
                }

                clk->csrc = nv_clk_src_core;
                clk->ccoef = (N << 8) | M;

                clk->cctrl = (P2 + 1) << 16;
                clk->cpost = (1 << P1) << 16;
        }

        /* sclk: nvpll + divisor, href or spll */
        out = 0;
        if (shader == nvkm_clk_read(&clk->base, nv_clk_src_href)) {
                clk->ssrc = nv_clk_src_href;
        } else {
                clock = calc_pll(clk, 0x4020, shader, &N, &M, &P1);
                if (clk->csrc == nv_clk_src_core)
                        out = calc_P((core << 1), shader, &divs);

                if (abs(shader - out) <=
                    abs(shader - clock) &&
                   (divs + P2) <= 7) {
                        clk->ssrc = nv_clk_src_core;
                        clk->sctrl = (divs + P2) << 16;
                } else {
                        clk->ssrc = nv_clk_src_shader;
                        clk->scoef = (N << 8) | M;
                        clk->sctrl = P1 << 16;
                }
        }

        /* vclk */
        out = calc_P(core, vdec, &divs);
        clock = calc_P(500000, vdec, &P1);
        if(abs(vdec - out) <= abs(vdec - clock)) {
                clk->vsrc = nv_clk_src_cclk;
                clk->vdiv = divs << 16;
        } else {
                clk->vsrc = nv_clk_src_vdec;
                clk->vdiv = P1 << 16;
        }

        /* Print strategy! */
        nvkm_debug(subdev, "nvpll: %08x %08x %08x\n",
                   clk->ccoef, clk->cpost, clk->cctrl);
        nvkm_debug(subdev, " spll: %08x %08x %08x\n",
                   clk->scoef, clk->spost, clk->sctrl);
        nvkm_debug(subdev, " vdiv: %08x\n", clk->vdiv);
        if (clk->csrc == nv_clk_src_hclkm4)
                nvkm_debug(subdev, "core: hrefm4\n");
        else
                nvkm_debug(subdev, "core: nvpll\n");

        if (clk->ssrc == nv_clk_src_hclkm4)
                nvkm_debug(subdev, "shader: hrefm4\n");
        else if (clk->ssrc == nv_clk_src_core)
                nvkm_debug(subdev, "shader: nvpll\n");
        else
                nvkm_debug(subdev, "shader: spll\n");

        if (clk->vsrc == nv_clk_src_hclkm4)
                nvkm_debug(subdev, "vdec: 500MHz\n");
        else
                nvkm_debug(subdev, "vdec: core\n");

        return 0;
}

static int
mcp77_clk_prog(struct nvkm_clk *base)
{
        struct mcp77_clk *clk = mcp77_clk(base);
        struct nvkm_subdev *subdev = &clk->base.subdev;
        struct nvkm_device *device = subdev->device;
        u32 pllmask = 0, mast;
        unsigned long flags;
        unsigned long *f = &flags;
        int ret = 0;

        ret = gt215_clk_pre(&clk->base, f);
        if (ret)
                goto out;

        /* First switch to safe clocks: href */
        mast = nvkm_mask(device, 0xc054, 0x03400e70, 0x03400640);
        mast &= ~0x00400e73;
        mast |= 0x03000000;

        switch (clk->csrc) {
        case nv_clk_src_hclkm4:
                nvkm_mask(device, 0x4028, 0x00070000, clk->cctrl);
                mast |= 0x00000002;
                break;
        case nv_clk_src_core:
                nvkm_wr32(device, 0x402c, clk->ccoef);
                nvkm_wr32(device, 0x4028, 0x80000000 | clk->cctrl);
                nvkm_wr32(device, 0x4040, clk->cpost);
                pllmask |= (0x3 << 8);
                mast |= 0x00000003;
                break;
        default:
                nvkm_warn(subdev, "Reclocking failed: unknown core clock\n");
                goto resume;
        }

        switch (clk->ssrc) {
        case nv_clk_src_href:
                nvkm_mask(device, 0x4020, 0x00070000, 0x00000000);
                /* mast |= 0x00000000; */
                break;
        case nv_clk_src_core:
                nvkm_mask(device, 0x4020, 0x00070000, clk->sctrl);
                mast |= 0x00000020;
                break;
        case nv_clk_src_shader:
                nvkm_wr32(device, 0x4024, clk->scoef);
                nvkm_wr32(device, 0x4020, 0x80000000 | clk->sctrl);
                nvkm_wr32(device, 0x4070, clk->spost);
                pllmask |= (0x3 << 12);
                mast |= 0x00000030;
                break;
        default:
                nvkm_warn(subdev, "Reclocking failed: unknown sclk clock\n");
                goto resume;
        }

        if (nvkm_msec(device, 2000,
                u32 tmp = nvkm_rd32(device, 0x004080) & pllmask;
                if (tmp == pllmask)
                        break;
        ) < 0)
                goto resume;

        switch (clk->vsrc) {
        case nv_clk_src_cclk:
                mast |= 0x00400000;
                fallthrough;
        default:
                nvkm_wr32(device, 0x4600, clk->vdiv);
        }

        nvkm_wr32(device, 0xc054, mast);

resume:
        /* Disable some PLLs and dividers when unused */
        if (clk->csrc != nv_clk_src_core) {
                nvkm_wr32(device, 0x4040, 0x00000000);
                nvkm_mask(device, 0x4028, 0x80000000, 0x00000000);
        }

        if (clk->ssrc != nv_clk_src_shader) {
                nvkm_wr32(device, 0x4070, 0x00000000);
                nvkm_mask(device, 0x4020, 0x80000000, 0x00000000);
        }

out:
        if (ret == -EBUSY)
                f = NULL;

        gt215_clk_post(&clk->base, f);
        return ret;
}

static void
mcp77_clk_tidy(struct nvkm_clk *base)
{
}

static const struct nvkm_clk_func
mcp77_clk = {
        .read = mcp77_clk_read,
        .calc = mcp77_clk_calc,
        .prog = mcp77_clk_prog,
        .tidy = mcp77_clk_tidy,
        .domains = {
                { nv_clk_src_crystal, 0xff },
                { nv_clk_src_href   , 0xff },
                { nv_clk_src_core   , 0xff, 0, "core", 1000 },
                { nv_clk_src_shader , 0xff, 0, "shader", 1000 },
                { nv_clk_src_vdec   , 0xff, 0, "vdec", 1000 },
                { nv_clk_src_max }
        }
};

int
mcp77_clk_new(struct nvkm_device *device, enum nvkm_subdev_type type, int inst,
              struct nvkm_clk **pclk)
{
        struct mcp77_clk *clk;

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

        return nvkm_clk_ctor(&mcp77_clk, device, type, inst, true, &clk->base);
}