/*
 * 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_ON(1);
	}

	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);
}