btcx-risc.c

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/*

    btcx-risc.c

    bt848/bt878/cx2388x risc code generator.

    (c) 2000-03 Gerd Knorr <[email protected]> [SuSE Labs]

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

*/

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

#include "btcx-risc.h"

MODULE_DESCRIPTION("some code shared by bttv and cx88xx drivers");
MODULE_AUTHOR("Gerd Knorr");
MODULE_LICENSE("GPL");

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

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

static int memcnt;

void btcx_riscmem_free(struct pci_dev *pci,
               struct btcx_riscmem *risc)
{
    if (NULL == risc->cpu)
        return;
    if (debug) {
        memcnt--;
        printk("btcx: riscmem free [%d] dma=%lx\n",
               memcnt, (unsigned long)risc->dma);
    }
    pci_free_consistent(pci, 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 = pci_alloc_consistent(pci, size, &dma);
        if (NULL == cpu)
            return -ENOMEM;
        risc->cpu  = cpu;
        risc->dma  = dma;
        risc->size = size;
        if (debug) {
            memcnt++;
            printk("btcx: riscmem alloc [%d] dma=%lx cpu=%p size=%d\n",
                   memcnt, (unsigned long)dma, cpu, size);
        }
    }
    memset(risc->cpu,0,risc->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;
    if (debug)
        printk(KERN_DEBUG "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;
        if (debug)
            printk(KERN_DEBUG "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)
{
    struct v4l2_clip swap;
    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] = clips[j+1];
                clips[j+1] = swap;
                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 (debug) {
        printk(KERN_DEBUG "btcx: skips line %d-%d:",line,maxline);
        for (skip = 0; skip < *nskips; skip++) {
            printk(" %d-%d",skips[skip].start,skips[skip].end);
        }
        printk("\n");
    }
}

/* ---------------------------------------------------------- */

EXPORT_SYMBOL(btcx_riscmem_alloc);
EXPORT_SYMBOL(btcx_riscmem_free);

EXPORT_SYMBOL(btcx_screen_clips);
EXPORT_SYMBOL(btcx_align);
EXPORT_SYMBOL(btcx_sort_clips);
EXPORT_SYMBOL(btcx_calc_skips);

/*
 * Local variables:
 * c-basic-offset: 8
 * End:
 */