/*
 * 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
 */
#include "nv50.h"
#include "pll.h"
#include "seq.h"

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

static u32
read_div(struct nv50_clk *clk)
{
        struct nvkm_device *device = clk->base.subdev.device;
        switch (device->chipset) {
        case 0x50: /* it exists, but only has bit 31, not the dividers.. */
        case 0x84:
        case 0x86:
        case 0x98:
        case 0xa0:
                return nvkm_rd32(device, 0x004700);
        case 0x92:
        case 0x94:
        case 0x96:
                return nvkm_rd32(device, 0x004800);
        default:
                return 0x00000000;
        }
}

static u32
read_pll_src(struct nv50_clk *clk, u32 base)
{
        struct nvkm_subdev *subdev = &clk->base.subdev;
        struct nvkm_device *device = subdev->device;
        u32 coef, ref = nvkm_clk_read(&clk->base, nv_clk_src_crystal);
        u32 rsel = nvkm_rd32(device, 0x00e18c);
        int P, N, M, id;

        switch (device->chipset) {
        case 0x50:
        case 0xa0:
                switch (base) {
                case 0x4020:
                case 0x4028: id = !!(rsel & 0x00000004); break;
                case 0x4008: id = !!(rsel & 0x00000008); break;
                case 0x4030: id = 0; break;
                default:
                        nvkm_error(subdev, "ref: bad pll %06x\n", base);
                        return 0;
                }

                coef = nvkm_rd32(device, 0x00e81c + (id * 0x0c));
                ref *=  (coef & 0x01000000) ? 2 : 4;
                P    =  (coef & 0x00070000) >> 16;
                N    = ((coef & 0x0000ff00) >> 8) + 1;
                M    = ((coef & 0x000000ff) >> 0) + 1;
                break;
        case 0x84:
        case 0x86:
        case 0x92:
                coef = nvkm_rd32(device, 0x00e81c);
                P    = (coef & 0x00070000) >> 16;
                N    = (coef & 0x0000ff00) >> 8;
                M    = (coef & 0x000000ff) >> 0;
                break;
        case 0x94:
        case 0x96:
        case 0x98:
                rsel = nvkm_rd32(device, 0x00c050);
                switch (base) {
                case 0x4020: rsel = (rsel & 0x00000003) >> 0; break;
                case 0x4008: rsel = (rsel & 0x0000000c) >> 2; break;
                case 0x4028: rsel = (rsel & 0x00001800) >> 11; break;
                case 0x4030: rsel = 3; break;
                default:
                        nvkm_error(subdev, "ref: bad pll %06x\n", base);
                        return 0;
                }

                switch (rsel) {
                case 0: id = 1; break;
                case 1: return nvkm_clk_read(&clk->base, nv_clk_src_crystal);
                case 2: return nvkm_clk_read(&clk->base, nv_clk_src_href);
                case 3: id = 0; break;
                }

                coef =  nvkm_rd32(device, 0x00e81c + (id * 0x28));
                P    = (nvkm_rd32(device, 0x00e824 + (id * 0x28)) >> 16) & 7;
                P   += (coef & 0x00070000) >> 16;
                N    = (coef & 0x0000ff00) >> 8;
                M    = (coef & 0x000000ff) >> 0;
                break;
        default:
                BUG();
        }

        if (M)
                return (ref * N / M) >> P;

        return 0;
}

static u32
read_pll_ref(struct nv50_clk *clk, u32 base)
{
        struct nvkm_subdev *subdev = &clk->base.subdev;
        struct nvkm_device *device = subdev->device;
        u32 src, mast = nvkm_rd32(device, 0x00c040);

        switch (base) {
        case 0x004028:
                src = !!(mast & 0x00200000);
                break;
        case 0x004020:
                src = !!(mast & 0x00400000);
                break;
        case 0x004008:
                src = !!(mast & 0x00010000);
                break;
        case 0x004030:
                src = !!(mast & 0x02000000);
                break;
        case 0x00e810:
                return nvkm_clk_read(&clk->base, nv_clk_src_crystal);
        default:
                nvkm_error(subdev, "bad pll %06x\n", base);
                return 0;
        }

        if (src)
                return nvkm_clk_read(&clk->base, nv_clk_src_href);

        return read_pll_src(clk, base);
}

static u32
read_pll(struct nv50_clk *clk, u32 base)
{
        struct nvkm_device *device = clk->base.subdev.device;
        u32 mast = nvkm_rd32(device, 0x00c040);
        u32 ctrl = nvkm_rd32(device, base + 0);
        u32 coef = nvkm_rd32(device, base + 4);
        u32 ref = read_pll_ref(clk, base);
        u32 freq = 0;
        int N1, N2, M1, M2;

        if (base == 0x004028 && (mast & 0x00100000)) {
                /* wtf, appears to only disable post-divider on gt200 */
                if (device->chipset != 0xa0)
                        return nvkm_clk_read(&clk->base, nv_clk_src_dom6);
        }

        N2 = (coef & 0xff000000) >> 24;
        M2 = (coef & 0x00ff0000) >> 16;
        N1 = (coef & 0x0000ff00) >> 8;
        M1 = (coef & 0x000000ff);
        if ((ctrl & 0x80000000) && M1) {
                freq = ref * N1 / M1;
                if ((ctrl & 0x40000100) == 0x40000000) {
                        if (M2)
                                freq = freq * N2 / M2;
                        else
                                freq = 0;
                }
        }

        return freq;
}

int
nv50_clk_read(struct nvkm_clk *base, enum nv_clk_src src)
{
        struct nv50_clk *clk = nv50_clk(base);
        struct nvkm_subdev *subdev = &clk->base.subdev;
        struct nvkm_device *device = subdev->device;
        u32 mast = nvkm_rd32(device, 0x00c040);
        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_hclk:
                return div_u64((u64)nvkm_clk_read(&clk->base, nv_clk_src_href) * 27778, 10000);
        case nv_clk_src_hclkm3:
                return nvkm_clk_read(&clk->base, nv_clk_src_hclk) * 3;
        case nv_clk_src_hclkm3d2:
                return nvkm_clk_read(&clk->base, nv_clk_src_hclk) * 3 / 2;
        case nv_clk_src_host:
                switch (mast & 0x30000000) {
                case 0x00000000: return nvkm_clk_read(&clk->base, nv_clk_src_href);
                case 0x10000000: break;
                case 0x20000000: /* !0x50 */
                case 0x30000000: return nvkm_clk_read(&clk->base, nv_clk_src_hclk);
                }
                break;
        case nv_clk_src_core:
                if (!(mast & 0x00100000))
                        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 nvkm_clk_read(&clk->base, nv_clk_src_dom6);
                case 0x00000002: return read_pll(clk, 0x004020) >> P;
                case 0x00000003: return read_pll(clk, 0x004028) >> P;
                }
                break;
        case nv_clk_src_shader:
                P = (nvkm_rd32(device, 0x004020) & 0x00070000) >> 16;
                switch (mast & 0x00000030) {
                case 0x00000000:
                        if (mast & 0x00000080)
                                return nvkm_clk_read(&clk->base, nv_clk_src_host) >> 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:
                P = (nvkm_rd32(device, 0x004008) & 0x00070000) >> 16;
                if (nvkm_rd32(device, 0x004008) & 0x00000200) {
                        switch (mast & 0x0000c000) {
                        case 0x00000000:
                                return nvkm_clk_read(&clk->base, nv_clk_src_crystal) >> P;
                        case 0x00008000:
                        case 0x0000c000:
                                return nvkm_clk_read(&clk->base, nv_clk_src_href) >> P;
                        }
                } else {
                        return read_pll(clk, 0x004008) >> P;
                }
                break;
        case nv_clk_src_vdec:
                P = (read_div(clk) & 0x00000700) >> 8;
                switch (device->chipset) {
                case 0x84:
                case 0x86:
                case 0x92:
                case 0x94:
                case 0x96:
                case 0xa0:
                        switch (mast & 0x00000c00) {
                        case 0x00000000:
                                if (device->chipset == 0xa0) /* wtf?? */
                                        return nvkm_clk_read(&clk->base, nv_clk_src_core) >> P;
                                return nvkm_clk_read(&clk->base, nv_clk_src_crystal) >> P;
                        case 0x00000400:
                                return 0;
                        case 0x00000800:
                                if (mast & 0x01000000)
                                        return read_pll(clk, 0x004028) >> P;
                                return read_pll(clk, 0x004030) >> P;
                        case 0x00000c00:
                                return nvkm_clk_read(&clk->base, nv_clk_src_core) >> P;
                        }
                        break;
                case 0x98:
                        switch (mast & 0x00000c00) {
                        case 0x00000000:
                                return nvkm_clk_read(&clk->base, nv_clk_src_core) >> P;
                        case 0x00000400:
                                return 0;
                        case 0x00000800:
                                return nvkm_clk_read(&clk->base, nv_clk_src_hclkm3d2) >> P;
                        case 0x00000c00:
                                return nvkm_clk_read(&clk->base, nv_clk_src_mem) >> P;
                        }
                        break;
                }
                break;
        case nv_clk_src_dom6:
                switch (device->chipset) {
                case 0x50:
                case 0xa0:
                        return read_pll(clk, 0x00e810) >> 2;
                case 0x84:
                case 0x86:
                case 0x92:
                case 0x94:
                case 0x96:
                case 0x98:
                        P = (read_div(clk) & 0x00000007) >> 0;
                        switch (mast & 0x0c000000) {
                        case 0x00000000: return nvkm_clk_read(&clk->base, nv_clk_src_href);
                        case 0x04000000: break;
                        case 0x08000000: return nvkm_clk_read(&clk->base, nv_clk_src_hclk);
                        case 0x0c000000:
                                return nvkm_clk_read(&clk->base, nv_clk_src_hclkm3) >> P;
                        }
                        break;
                default:
                        break;
                }
        default:
                break;
        }

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

static u32
calc_pll(struct nv50_clk *clk, u32 reg, u32 idx, 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 = read_pll_ref(clk, reg);
        if (!pll.refclk)
                return 0;

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

static inline u32
calc_div(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 inline u32
clk_same(u32 a, u32 b)
{
        return ((a / 1000) == (b / 1000));
}

int
nv50_clk_calc(struct nvkm_clk *base, struct nvkm_cstate *cstate)
{
        struct nv50_clk *clk = nv50_clk(base);
        struct nv50_clk_hwsq *hwsq = &clk->hwsq;
        struct nvkm_subdev *subdev = &clk->base.subdev;
        struct nvkm_device *device = subdev->device;
        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];
        const int dom6 = cstate->domain[nv_clk_src_dom6];
        u32 mastm = 0, mastv = 0;
        u32 divsm = 0, divsv = 0;
        int N, M, P1, P2;
        int freq, out;

        /* prepare a hwsq script from which we'll perform the reclock */
        out = clk_init(hwsq, subdev);
        if (out)
                return out;

        clk_wr32(hwsq, fifo, 0x00000001); /* block fifo */
        clk_nsec(hwsq, 8000);
        clk_setf(hwsq, 0x10, 0x00); /* disable fb */
        clk_wait(hwsq, 0x00, 0x01); /* wait for fb disabled */

        /* vdec: avoid modifying xpll until we know exactly how the other
         * clock domains work, i suspect at least some of them can also be
         * tied to xpll...
         */
        if (vdec) {
                /* see how close we can get using nvclk as a source */
                freq = calc_div(core, vdec, &P1);

                /* see how close we can get using xpll/hclk as a source */
                if (device->chipset != 0x98)
                        out = read_pll(clk, 0x004030);
                else
                        out = nvkm_clk_read(&clk->base, nv_clk_src_hclkm3d2);
                out = calc_div(out, vdec, &P2);

                /* select whichever gets us closest */
                if (abs(vdec - freq) <= abs(vdec - out)) {
                        if (device->chipset != 0x98)
                                mastv |= 0x00000c00;
                        divsv |= P1 << 8;
                } else {
                        mastv |= 0x00000800;
                        divsv |= P2 << 8;
                }

                mastm |= 0x00000c00;
                divsm |= 0x00000700;
        }

        /* dom6: nfi what this is, but we're limited to various combinations
         * of the host clock frequency
         */
        if (dom6) {
                if (clk_same(dom6, nvkm_clk_read(&clk->base, nv_clk_src_href))) {
                        mastv |= 0x00000000;
                } else
                if (clk_same(dom6, nvkm_clk_read(&clk->base, nv_clk_src_hclk))) {
                        mastv |= 0x08000000;
                } else {
                        freq = nvkm_clk_read(&clk->base, nv_clk_src_hclk) * 3;
                        calc_div(freq, dom6, &P1);

                        mastv |= 0x0c000000;
                        divsv |= P1;
                }

                mastm |= 0x0c000000;
                divsm |= 0x00000007;
        }

        /* vdec/dom6: switch to "safe" clocks temporarily, update dividers
         * and then switch to target clocks
         */
        clk_mask(hwsq, mast, mastm, 0x00000000);
        clk_mask(hwsq, divs, divsm, divsv);
        clk_mask(hwsq, mast, mastm, mastv);

        /* core/shader: disconnect nvclk/sclk from their PLLs (nvclk to dom6,
         * sclk to hclk) before reprogramming
         */
        if (device->chipset < 0x92)
                clk_mask(hwsq, mast, 0x001000b0, 0x00100080);
        else
                clk_mask(hwsq, mast, 0x000000b3, 0x00000081);

        /* core: for the moment at least, always use nvpll */
        freq = calc_pll(clk, 0x4028, core, &N, &M, &P1);
        if (freq == 0)
                return -ERANGE;

        clk_mask(hwsq, nvpll[0], 0xc03f0100,
                                 0x80000000 | (P1 << 19) | (P1 << 16));
        clk_mask(hwsq, nvpll[1], 0x0000ffff, (N << 8) | M);

        /* shader: tie to nvclk if possible, otherwise use spll.  have to be
         * very careful that the shader clock is at least twice the core, or
         * some chipsets will be very unhappy.  i expect most or all of these
         * cases will be handled by tying to nvclk, but it's possible there's
         * corners
         */
        if (P1-- && shader == (core << 1)) {
                clk_mask(hwsq, spll[0], 0xc03f0100, (P1 << 19) | (P1 << 16));
                clk_mask(hwsq, mast, 0x00100033, 0x00000023);
        } else {
                freq = calc_pll(clk, 0x4020, shader, &N, &M, &P1);
                if (freq == 0)
                        return -ERANGE;

                clk_mask(hwsq, spll[0], 0xc03f0100,
                                        0x80000000 | (P1 << 19) | (P1 << 16));
                clk_mask(hwsq, spll[1], 0x0000ffff, (N << 8) | M);
                clk_mask(hwsq, mast, 0x00100033, 0x00000033);
        }

        /* restore normal operation */
        clk_setf(hwsq, 0x10, 0x01); /* enable fb */
        clk_wait(hwsq, 0x00, 0x00); /* wait for fb enabled */
        clk_wr32(hwsq, fifo, 0x00000000); /* un-block fifo */
        return 0;
}

int
nv50_clk_prog(struct nvkm_clk *base)
{
        struct nv50_clk *clk = nv50_clk(base);
        return clk_exec(&clk->hwsq, true);
}

void
nv50_clk_tidy(struct nvkm_clk *base)
{
        struct nv50_clk *clk = nv50_clk(base);
        clk_exec(&clk->hwsq, false);
}

int
nv50_clk_new_(const struct nvkm_clk_func *func, struct nvkm_device *device,
              int index, bool allow_reclock, struct nvkm_clk **pclk)
{
        struct nv50_clk *clk;
        int ret;

        if (!(clk = kzalloc(sizeof(*clk), GFP_KERNEL)))
                return -ENOMEM;
        ret = nvkm_clk_ctor(func, device, index, allow_reclock, &clk->base);
        *pclk = &clk->base;
        if (ret)
                return ret;

        clk->hwsq.r_fifo = hwsq_reg(0x002504);
        clk->hwsq.r_spll[0] = hwsq_reg(0x004020);
        clk->hwsq.r_spll[1] = hwsq_reg(0x004024);
        clk->hwsq.r_nvpll[0] = hwsq_reg(0x004028);
        clk->hwsq.r_nvpll[1] = hwsq_reg(0x00402c);
        switch (device->chipset) {
        case 0x92:
        case 0x94:
        case 0x96:
                clk->hwsq.r_divs = hwsq_reg(0x004800);
                break;
        default:
                clk->hwsq.r_divs = hwsq_reg(0x004700);
                break;
        }
        clk->hwsq.r_mast = hwsq_reg(0x00c040);
        return 0;
}

static const struct nvkm_clk_func
nv50_clk = {
        .read = nv50_clk_read,
        .calc = nv50_clk_calc,
        .prog = nv50_clk_prog,
        .tidy = nv50_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_mem    , 0xff, 0, "memory", 1000 },
                { nv_clk_src_max }
        }
};

int
nv50_clk_new(struct nvkm_device *device, int index, struct nvkm_clk **pclk)
{
        return nv50_clk_new_(&nv50_clk, device, index, false, pclk);
}