// SPDX-License-Identifier: GPL-2.0-or-later
/*

    btcx-risc.c

    bt848/bt878/cx2388x risc code generator.

    (c) 2000-03 Gerd Knorr <kraxel@bytesex.org> [SuSE Labs]


*/

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/interrupt.h>
#include <linux/videodev2.h>
#include <linux/pgtable.h>
#include <asm/page.h>

#include "btcx-risc.h"

static unsigned int btcx_debug;
module_param(btcx_debug, int, 0644);
MODULE_PARM_DESC(btcx_debug,"debug messages, default is 0 (no)");

#define dprintk(fmt, arg...) do {				\
	if (btcx_debug)						\
		printk(KERN_DEBUG pr_fmt("%s: " fmt),		\
		       __func__, ##arg);			\
} while (0)


/* ---------------------------------------------------------- */
/* allocate/free risc memory                                  */

static int memcnt;

void btcx_riscmem_free(struct pci_dev *pci,
		       struct btcx_riscmem *risc)
{
	if (NULL == risc->cpu)
		return;

	memcnt--;
	dprintk("btcx: riscmem free [%d] dma=%lx\n",
		memcnt, (unsigned long)risc->dma);

	dma_free_coherent(&pci->dev, risc->size, risc->cpu, risc->dma);
	memset(risc,0,sizeof(*risc));
}

int btcx_riscmem_alloc(struct pci_dev *pci,
		       struct btcx_riscmem *risc,
		       unsigned int size)
{
	__le32 *cpu;
	dma_addr_t dma = 0;

	if (NULL != risc->cpu && risc->size < size)
		btcx_riscmem_free(pci,risc);
	if (NULL == risc->cpu) {
		cpu = dma_alloc_coherent(&pci->dev, size, &dma, GFP_KERNEL);
		if (NULL == cpu)
			return -ENOMEM;
		risc->cpu  = cpu;
		risc->dma  = dma;
		risc->size = size;

		memcnt++;
		dprintk("btcx: riscmem alloc [%d] dma=%lx cpu=%p size=%d\n",
			memcnt, (unsigned long)dma, cpu, size);
	}
	return 0;
}

/* ---------------------------------------------------------- */
/* screen overlay helpers                                     */

int
btcx_screen_clips(int swidth, int sheight, struct v4l2_rect *win,
		  struct v4l2_clip *clips, unsigned int n)
{
	if (win->left < 0) {
		/* left */
		clips[n].c.left = 0;
		clips[n].c.top = 0;
		clips[n].c.width  = -win->left;
		clips[n].c.height = win->height;
		n++;
	}
	if (win->left + win->width > swidth) {
		/* right */
		clips[n].c.left   = swidth - win->left;
		clips[n].c.top    = 0;
		clips[n].c.width  = win->width - clips[n].c.left;
		clips[n].c.height = win->height;
		n++;
	}
	if (win->top < 0) {
		/* top */
		clips[n].c.left = 0;
		clips[n].c.top = 0;
		clips[n].c.width  = win->width;
		clips[n].c.height = -win->top;
		n++;
	}
	if (win->top + win->height > sheight) {
		/* bottom */
		clips[n].c.left = 0;
		clips[n].c.top = sheight - win->top;
		clips[n].c.width  = win->width;
		clips[n].c.height = win->height - clips[n].c.top;
		n++;
	}
	return n;
}

int
btcx_align(struct v4l2_rect *win, struct v4l2_clip *clips, unsigned int n, int mask)
{
	s32 nx,nw,dx;
	unsigned int i;

	/* fixup window */
	nx = (win->left + mask) & ~mask;
	nw = (win->width) & ~mask;
	if (nx + nw > win->left + win->width)
		nw -= mask+1;
	dx = nx - win->left;
	win->left  = nx;
	win->width = nw;
	dprintk("btcx: window align %dx%d+%d+%d [dx=%d]\n",
	       win->width, win->height, win->left, win->top, dx);

	/* fixup clips */
	for (i = 0; i < n; i++) {
		nx = (clips[i].c.left-dx) & ~mask;
		nw = (clips[i].c.width) & ~mask;
		if (nx + nw < clips[i].c.left-dx + clips[i].c.width)
			nw += mask+1;
		clips[i].c.left  = nx;
		clips[i].c.width = nw;
		dprintk("btcx:   clip align %dx%d+%d+%d\n",
		       clips[i].c.width, clips[i].c.height,
		       clips[i].c.left, clips[i].c.top);
	}
	return 0;
}

void
btcx_sort_clips(struct v4l2_clip *clips, unsigned int nclips)
{
	int i,j,n;

	if (nclips < 2)
		return;
	for (i = nclips-2; i >= 0; i--) {
		for (n = 0, j = 0; j <= i; j++) {
			if (clips[j].c.left > clips[j+1].c.left) {
				swap(clips[j], clips[j + 1]);
				n++;
			}
		}
		if (0 == n)
			break;
	}
}

void
btcx_calc_skips(int line, int width, int *maxy,
		struct btcx_skiplist *skips, unsigned int *nskips,
		const struct v4l2_clip *clips, unsigned int nclips)
{
	unsigned int clip,skip;
	int end, maxline;

	skip=0;
	maxline = 9999;
	for (clip = 0; clip < nclips; clip++) {

		/* sanity checks */
		if (clips[clip].c.left + clips[clip].c.width <= 0)
			continue;
		if (clips[clip].c.left > (signed)width)
			break;

		/* vertical range */
		if (line > clips[clip].c.top+clips[clip].c.height-1)
			continue;
		if (line < clips[clip].c.top) {
			if (maxline > clips[clip].c.top-1)
				maxline = clips[clip].c.top-1;
			continue;
		}
		if (maxline > clips[clip].c.top+clips[clip].c.height-1)
			maxline = clips[clip].c.top+clips[clip].c.height-1;

		/* horizontal range */
		if (0 == skip || clips[clip].c.left > skips[skip-1].end) {
			/* new one */
			skips[skip].start = clips[clip].c.left;
			if (skips[skip].start < 0)
				skips[skip].start = 0;
			skips[skip].end = clips[clip].c.left + clips[clip].c.width;
			if (skips[skip].end > width)
				skips[skip].end = width;
			skip++;
		} else {
			/* overlaps -- expand last one */
			end = clips[clip].c.left + clips[clip].c.width;
			if (skips[skip-1].end < end)
				skips[skip-1].end = end;
			if (skips[skip-1].end > width)
				skips[skip-1].end = width;
		}
	}
	*nskips = skip;
	*maxy = maxline;

	if (btcx_debug) {
		dprintk("btcx: skips line %d-%d:", line, maxline);
		for (skip = 0; skip < *nskips; skip++) {
			pr_cont(" %d-%d", skips[skip].start, skips[skip].end);
		}
		pr_cont("\n");
	}
}