/*
 * tiler-geom.c
 *
 * TILER geometry functions for TI TILER hardware block.
 *
 * Author: Lajos Molnar <molnar@ti.com>
 *
 * Copyright (C) 2009-2010 Texas Instruments, Inc.
 *
 * This package is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * THIS PACKAGE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#include <linux/module.h>
#include "_tiler.h"

/* bits representing the same slot in DMM-TILER hw-block */
#define SLOT_WIDTH_BITS		6
#define SLOT_HEIGHT_BITS	6

/* bits reserved to describe coordinates in DMM-TILER hw-block */
#define CONT_WIDTH_BITS		14
#define CONT_HEIGHT_BITS	13

static struct tiler_geom geom[TILER_FORMATS] = {
	{
		.x_shft = 0,
		.y_shft = 0,
	},
	{
		.x_shft = 0,
		.y_shft = 1,
	},
	{
		.x_shft = 1,
		.y_shft = 1,
	},
	{
		.x_shft = SLOT_WIDTH_BITS,
		.y_shft = SLOT_HEIGHT_BITS,
	},
};

/* tiler space addressing bitfields */
#define MASK_XY_FLIP		(1 << 31)
#define MASK_Y_INVERT		(1 << 30)
#define MASK_X_INVERT		(1 << 29)
#define SHIFT_ACC_MODE		27
#define MASK_ACC_MODE		3

/* calculated constants */
#define TILER_PAGE		(1 << (SLOT_WIDTH_BITS + SLOT_HEIGHT_BITS))
#define TILER_WIDTH		(1 << (CONT_WIDTH_BITS - SLOT_WIDTH_BITS))
#define TILER_HEIGHT		(1 << (CONT_HEIGHT_BITS - SLOT_HEIGHT_BITS))

#define VIEW_SIZE		(1u << (CONT_WIDTH_BITS + CONT_HEIGHT_BITS))
#define VIEW_MASK		(VIEW_SIZE - 1u)

#define MASK(bits) ((1 << (bits)) - 1)

#define TILER_FMT(x)	((enum tiler_fmt) \
		((x >> SHIFT_ACC_MODE) & MASK_ACC_MODE))

#define MASK_VIEW		(MASK_X_INVERT | MASK_Y_INVERT | MASK_XY_FLIP)

/* location of the various tiler views in physical address space */
#define TILVIEW_8BIT	0x60000000u
#define TILVIEW_16BIT	(TILVIEW_8BIT  + VIEW_SIZE)
#define TILVIEW_32BIT	(TILVIEW_16BIT + VIEW_SIZE)
#define TILVIEW_PAGE	(TILVIEW_32BIT + VIEW_SIZE)
#define TILVIEW_END	(TILVIEW_PAGE  + VIEW_SIZE)

/* create tsptr by adding view orientation and access mode */
#define TIL_ADDR(x, orient, a)\
	((u32) (x) | (orient) | ((a) << SHIFT_ACC_MODE))

bool is_tiler_addr(u32 phys)
{
	return phys >= TILVIEW_8BIT && phys < TILVIEW_END;
}
EXPORT_SYMBOL(is_tiler_addr);

u32 tiler_bpp(const struct tiler_block_t *b)
{
	enum tiler_fmt fmt = tiler_fmt(b->phys);
	BUG_ON(fmt == TILFMT_INVALID);

	return geom[fmt].bpp_m;
}
EXPORT_SYMBOL(tiler_bpp);

/* return the stride of a tiler-block in tiler space */
static inline s32 tiler_stride(u32 tsptr)
{
	enum tiler_fmt fmt = TILER_FMT(tsptr);

	if (fmt == TILFMT_PAGE)
		return 0;
	else if (tsptr & MASK_XY_FLIP)
		return 1 << (CONT_HEIGHT_BITS + geom[fmt].x_shft);
	else
		return 1 << (CONT_WIDTH_BITS + geom[fmt].y_shft);
}

u32 tiler_pstride(const struct tiler_block_t *b)
{
	enum tiler_fmt fmt = tiler_fmt(b->phys);
	BUG_ON(fmt == TILFMT_INVALID);

	/* return the virtual stride for page mode */
	if (fmt == TILFMT_PAGE)
		return tiler_vstride(b);

	return tiler_stride(b->phys & ~MASK_VIEW);
}
EXPORT_SYMBOL(tiler_pstride);

enum tiler_fmt tiler_fmt(u32 phys)
{
	if (!is_tiler_addr(phys))
		return TILFMT_INVALID;

	return TILER_FMT(phys);
}
EXPORT_SYMBOL(tiler_fmt);

/* returns the tiler geometry information for a format */
static const struct tiler_geom *get_geom(enum tiler_fmt fmt)
{
	if (fmt >= TILFMT_MIN && fmt <= TILFMT_MAX)
		return geom + fmt;
	return NULL;
}

/**
 * Returns the natural x and y coordinates for a pixel in tiler space address.
 * That is, the coordinates for the same pixel in the natural (non-rotated,
 * non-mirrored) view. This allows to uniquely identify a tiler pixel in any
 * view orientation.
 */
static void tiler_get_natural_xy(u32 tsptr, u32 *x, u32 *y)
{
	u32 x_bits, y_bits, offset;
	enum tiler_fmt fmt;

	fmt = TILER_FMT(tsptr);

	x_bits = CONT_WIDTH_BITS - geom[fmt].x_shft;
	y_bits = CONT_HEIGHT_BITS - geom[fmt].y_shft;
	offset = (tsptr & VIEW_MASK) >> (geom[fmt].x_shft + geom[fmt].y_shft);

	/* separate coordinate bitfields based on view orientation */
	if (tsptr & MASK_XY_FLIP) {
		*x = offset >> y_bits;
		*y = offset & MASK(y_bits);
	} else {
		*x = offset & MASK(x_bits);
		*y = offset >> x_bits;
	}

	/* account for mirroring */
	if (tsptr & MASK_X_INVERT)
		*x ^= MASK(x_bits);
	if (tsptr & MASK_Y_INVERT)
		*y ^= MASK(y_bits);
}

/* calculate the tiler space address of a pixel in a view orientation */
static u32 tiler_get_address(u32 orient, enum tiler_fmt fmt, u32 x, u32 y)
{
	u32 x_bits, y_bits, tmp, x_mask, y_mask, alignment;

	x_bits = CONT_WIDTH_BITS - geom[fmt].x_shft;
	y_bits = CONT_HEIGHT_BITS - geom[fmt].y_shft;
	alignment = geom[fmt].x_shft + geom[fmt].y_shft;

	/* validate coordinate */
	x_mask = MASK(x_bits);
	y_mask = MASK(y_bits);
	if (x < 0 || x > x_mask || y < 0 || y > y_mask)
		return 0;

	/* account for mirroring */
	if (orient & MASK_X_INVERT)
		x ^= x_mask;
	if (orient & MASK_Y_INVERT)
		y ^= y_mask;

	/* get coordinate address */
	if (orient & MASK_XY_FLIP)
		tmp = ((x << y_bits) + y);
	else
		tmp = ((y << x_bits) + x);

	return TIL_ADDR((tmp << alignment), orient, fmt);
}

void tilview_create(struct tiler_view_t *view, u32 phys, u32 width, u32 height)
{
	BUG_ON(!is_tiler_addr(phys));

	view->tsptr = phys & ~MASK_VIEW;
	view->bpp = geom[TILER_FMT(phys)].bpp_m;
	view->width = width;
	view->height = height;
	view->h_inc = view->bpp;
	view->v_inc = tiler_stride(view->tsptr);
}
EXPORT_SYMBOL(tilview_create);

void tilview_get(struct tiler_view_t *view, struct tiler_block_t *blk)
{
	view->tsptr = blk->phys & ~MASK_VIEW;
	view->bpp = tiler_bpp(blk);
	view->width = blk->width;
	view->height = blk->height;
	view->h_inc = view->bpp;
	view->v_inc = tiler_stride(view->tsptr);
}
EXPORT_SYMBOL(tilview_get);

s32 tilview_crop(struct tiler_view_t *view, u32 left, u32 top, u32 width,
								u32 height)
{
	/* check for valid crop */
	if (left + width < left || left + width > view->width ||
	    top + height < top || top + height > view->height)
		return -EINVAL;

	view->tsptr += left * view->h_inc + top * view->v_inc;
	view->width = width;
	view->height = height;
	return 0;
}
EXPORT_SYMBOL(tilview_crop);

/* calculate tilerspace address and stride after view orientation change */
static void reorient(struct tiler_view_t *view, u32 orient)
{
	u32 x, y;

	tiler_get_natural_xy(view->tsptr, &x, &y);
	view->tsptr = tiler_get_address(orient,
					TILER_FMT(view->tsptr), x, y);
	view->v_inc = tiler_stride(view->tsptr);
}

s32 tilview_rotate(struct tiler_view_t *view, s32 rotation)
{
	u32 orient;

	if (rotation % 90)
		return -EINVAL;

	/* normalize rotation to quarters */
	rotation = (rotation / 90) & 3;
	if (!rotation)
		return 0; /* nothing to do */

	/* PAGE mode view cannot be rotated */
	if (TILER_FMT(view->tsptr) == TILFMT_PAGE)
		return -EPERM;

	/*
	 * first adjust top-left corner. NOTE: it rotates counter-clockwise:
	 * 0 < 3
	 * v   ^
	 * 1 > 2
	 */
	if (rotation < 3)
		view->tsptr += (view->height - 1) * view->v_inc;
	if (rotation > 1)
		view->tsptr += (view->width - 1) * view->h_inc;

	/* then rotate view itself */
	orient = view->tsptr & MASK_VIEW;

	/* rotate first 2 quarters */
	if (rotation & 2) {
		orient ^= MASK_X_INVERT;
		orient ^= MASK_Y_INVERT;
	}

	/* rotate last quarter */
	if (rotation & 1) {
		orient ^= (orient & MASK_XY_FLIP) ?
			MASK_X_INVERT : MASK_Y_INVERT;

		/* swap x & y */
		orient ^= MASK_XY_FLIP;
		swap(view->height, view->width);
	}

	/* finally reorient view */
	reorient(view, orient);
	return 0;
}
EXPORT_SYMBOL(tilview_rotate);

s32 tilview_flip(struct tiler_view_t *view, bool flip_x, bool flip_y)
{
	u32 orient;
	orient = view->tsptr & MASK_VIEW;

	if (!flip_x && !flip_y)
		return 0; /* nothing to do */

	/* PAGE mode view cannot be flipped */
	if (TILER_FMT(view->tsptr) == TILFMT_PAGE)
		return -EPERM;

	/* adjust top-left corner */
	if (flip_x)
		view->tsptr += (view->width - 1) * view->h_inc;
	if (flip_y)
		view->tsptr += (view->height - 1) * view->v_inc;

	/* flip view orientation */
	if (orient & MASK_XY_FLIP)
		swap(flip_x, flip_y);

	if (flip_x)
		orient ^= MASK_X_INVERT;
	if (flip_y)
		orient ^= MASK_Y_INVERT;

	/* finally reorient view */
	reorient(view, orient);
	return 0;
}
EXPORT_SYMBOL(tilview_flip);

/* return the alias address for a coordinate */
static inline u32 alias_address(enum tiler_fmt fmt, u32 x, u32 y)
{
	return tiler_get_address(0, fmt, x, y) + TILVIEW_8BIT;
}

/* get the coordinates for an alias address */
static inline void alias_xy(u32 ssptr, u32 *x, u32 *y)
{
	tiler_get_natural_xy(ssptr & ~MASK_VIEW, x, y);
}

/* initialize shared geometric data */
void tiler_geom_init(struct tiler_ops *tiler)
{
	struct tiler_geom *g;

	tiler->xy = alias_xy;
	tiler->addr = alias_address;
	tiler->geom = get_geom;

	tiler->page   = TILER_PAGE;
	tiler->width  = TILER_WIDTH;
	tiler->height = TILER_HEIGHT;

	/* calculate geometry */
	for (g = geom; g < geom + TILER_FORMATS; g++) {
		g->bpp_m = g->bpp = 1 << (g->x_shft + g->y_shft);
		g->slot_w = 1 << (SLOT_WIDTH_BITS - g->x_shft);
		g->slot_h = 1 << (SLOT_HEIGHT_BITS - g->y_shft);
	}

	/* set bpp_m = 1 for page mode as most applications deal in byte data */
	geom[TILFMT_PAGE].bpp_m = 1;
}