vrfb.c

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/*
 * VRFB Rotation Engine
 *
 * Copyright (C) 2009 Nokia Corporation
 * Author: Tomi Valkeinen <[email protected]>
 *
 * This program 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 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.,
 * 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

/*#define DEBUG*/

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/io.h>
#include <linux/bitops.h>
#include <linux/mutex.h>

#include <plat/vrfb.h>
#include <plat/sdrc.h>

#ifdef DEBUG
#define DBG(format, ...) pr_debug("VRFB: " format, ## __VA_ARGS__)
#else
#define DBG(format, ...)
#endif

#define SMS_ROT_VIRT_BASE(context, rot) \
    (((context >= 4) ? 0xD0000000 : 0x70000000) \
     + (0x4000000 * (context)) \
     + (0x1000000 * (rot)))

#define OMAP_VRFB_SIZE          (2048 * 2048 * 4)

#define VRFB_PAGE_WIDTH_EXP 5 /* Assuming SDRAM pagesize= 1024 */
#define VRFB_PAGE_HEIGHT_EXP    5 /* 1024 = 2^5 * 2^5 */
#define VRFB_PAGE_WIDTH     (1 << VRFB_PAGE_WIDTH_EXP)
#define VRFB_PAGE_HEIGHT    (1 << VRFB_PAGE_HEIGHT_EXP)
#define SMS_IMAGEHEIGHT_OFFSET  16
#define SMS_IMAGEWIDTH_OFFSET   0
#define SMS_PH_OFFSET       8
#define SMS_PW_OFFSET       4
#define SMS_PS_OFFSET       0

#define VRFB_NUM_CTXS 12
/* bitmap of reserved contexts */
static unsigned long ctx_map;

static DEFINE_MUTEX(ctx_lock);

/*
 * Access to this happens from client drivers or the PM core after wake-up.
 * For the first case we require locking at the driver level, for the second
 * we don't need locking, since no drivers will run until after the wake-up
 * has finished.
 */
static struct {
    u32 physical_ba;
    u32 control;
    u32 size;
} vrfb_hw_context[VRFB_NUM_CTXS];

static inline void restore_hw_context(int ctx)
{
    omap2_sms_write_rot_control(vrfb_hw_context[ctx].control, ctx);
    omap2_sms_write_rot_size(vrfb_hw_context[ctx].size, ctx);
    omap2_sms_write_rot_physical_ba(vrfb_hw_context[ctx].physical_ba, ctx);
}

static u32 get_image_width_roundup(u16 width, u8 bytespp)
{
    unsigned long stride = width * bytespp;
    unsigned long ceil_pages_per_stride = (stride / VRFB_PAGE_WIDTH) +
        (stride % VRFB_PAGE_WIDTH != 0);

    return ceil_pages_per_stride * VRFB_PAGE_WIDTH / bytespp;
}

/*
 * This the extra space needed in the VRFB physical area for VRFB to safely wrap
 * any memory accesses to the invisible part of the virtual view to the physical
 * area.
 */
static inline u32 get_extra_physical_size(u16 image_width_roundup, u8 bytespp)
{
    return (OMAP_VRFB_LINE_LEN - image_width_roundup) * VRFB_PAGE_HEIGHT *
        bytespp;
}

void omap_vrfb_restore_context(void)
{
    int i;
    unsigned long map = ctx_map;

    for (i = ffs(map); i; i = ffs(map)) {
        /* i=1..32 */
        i--;
        map &= ~(1 << i);
        restore_hw_context(i);
    }
}

void omap_vrfb_adjust_size(u16 *width, u16 *height,
        u8 bytespp)
{
    *width = ALIGN(*width * bytespp, VRFB_PAGE_WIDTH) / bytespp;
    *height = ALIGN(*height, VRFB_PAGE_HEIGHT);
}
EXPORT_SYMBOL(omap_vrfb_adjust_size);

u32 omap_vrfb_min_phys_size(u16 width, u16 height, u8 bytespp)
{
    unsigned long image_width_roundup = get_image_width_roundup(width,
        bytespp);

    if (image_width_roundup > OMAP_VRFB_LINE_LEN)
        return 0;

    return (width * height * bytespp) + get_extra_physical_size(
        image_width_roundup, bytespp);
}
EXPORT_SYMBOL(omap_vrfb_min_phys_size);

u16 omap_vrfb_max_height(u32 phys_size, u16 width, u8 bytespp)
{
    unsigned long image_width_roundup = get_image_width_roundup(width,
        bytespp);
    unsigned long height;
    unsigned long extra;

    if (image_width_roundup > OMAP_VRFB_LINE_LEN)
        return 0;

    extra = get_extra_physical_size(image_width_roundup, bytespp);

    if (phys_size < extra)
        return 0;

    height = (phys_size - extra) / (width * bytespp);

    /* Virtual views provided by VRFB are limited to 2048x2048. */
    return min_t(unsigned long, height, 2048);
}
EXPORT_SYMBOL(omap_vrfb_max_height);

void omap_vrfb_setup(struct vrfb *vrfb, unsigned long paddr,
        u16 width, u16 height,
        unsigned bytespp, bool yuv_mode)
{
    unsigned pixel_size_exp;
    u16 vrfb_width;
    u16 vrfb_height;
    u8 ctx = vrfb->context;
    u32 size;
    u32 control;

    DBG("omapfb_set_vrfb(%d, %lx, %dx%d, %d, %d)\n", ctx, paddr,
            width, height, bytespp, yuv_mode);

    /* For YUV2 and UYVY modes VRFB needs to handle pixels a bit
     * differently. See TRM. */
    if (yuv_mode) {
        bytespp *= 2;
        width /= 2;
    }

    if (bytespp == 4)
        pixel_size_exp = 2;
    else if (bytespp == 2)
        pixel_size_exp = 1;
    else {
        BUG();
        return;
    }

    vrfb_width = ALIGN(width * bytespp, VRFB_PAGE_WIDTH) / bytespp;
    vrfb_height = ALIGN(height, VRFB_PAGE_HEIGHT);

    DBG("vrfb w %u, h %u bytespp %d\n", vrfb_width, vrfb_height, bytespp);

    size  = vrfb_width << SMS_IMAGEWIDTH_OFFSET;
    size |= vrfb_height << SMS_IMAGEHEIGHT_OFFSET;

    control  = pixel_size_exp << SMS_PS_OFFSET;
    control |= VRFB_PAGE_WIDTH_EXP  << SMS_PW_OFFSET;
    control |= VRFB_PAGE_HEIGHT_EXP << SMS_PH_OFFSET;

    vrfb_hw_context[ctx].physical_ba = paddr;
    vrfb_hw_context[ctx].size = size;
    vrfb_hw_context[ctx].control = control;

    omap2_sms_write_rot_physical_ba(paddr, ctx);
    omap2_sms_write_rot_size(size, ctx);
    omap2_sms_write_rot_control(control, ctx);

    DBG("vrfb offset pixels %d, %d\n",
            vrfb_width - width, vrfb_height - height);

    vrfb->xres = width;
    vrfb->yres = height;
    vrfb->xoffset = vrfb_width - width;
    vrfb->yoffset = vrfb_height - height;
    vrfb->bytespp = bytespp;
    vrfb->yuv_mode = yuv_mode;
}
EXPORT_SYMBOL(omap_vrfb_setup);

int omap_vrfb_map_angle(struct vrfb *vrfb, u16 height, u8 rot)
{
    unsigned long size = height * OMAP_VRFB_LINE_LEN * vrfb->bytespp;

    vrfb->vaddr[rot] = ioremap_wc(vrfb->paddr[rot], size);

    if (!vrfb->vaddr[rot]) {
        printk(KERN_ERR "vrfb: ioremap failed\n");
        return -ENOMEM;
    }

    DBG("ioremapped vrfb area %d of size %lu into %p\n", rot, size,
        vrfb->vaddr[rot]);

    return 0;
}
EXPORT_SYMBOL(omap_vrfb_map_angle);

void omap_vrfb_release_ctx(struct vrfb *vrfb)
{
    int rot;
    int ctx = vrfb->context;

    if (ctx == 0xff)
        return;

    DBG("release ctx %d\n", ctx);

    mutex_lock(&ctx_lock);

    BUG_ON(!(ctx_map & (1 << ctx)));

    clear_bit(ctx, &ctx_map);

    for (rot = 0; rot < 4; ++rot) {
        if (vrfb->paddr[rot]) {
            release_mem_region(vrfb->paddr[rot], OMAP_VRFB_SIZE);
            vrfb->paddr[rot] = 0;
        }
    }

    vrfb->context = 0xff;

    mutex_unlock(&ctx_lock);
}
EXPORT_SYMBOL(omap_vrfb_release_ctx);

int omap_vrfb_request_ctx(struct vrfb *vrfb)
{
    int rot;
    u32 paddr;
    u8 ctx;
    int r;

    DBG("request ctx\n");

    mutex_lock(&ctx_lock);

    for (ctx = 0; ctx < VRFB_NUM_CTXS; ++ctx)
        if ((ctx_map & (1 << ctx)) == 0)
            break;

    if (ctx == VRFB_NUM_CTXS) {
        pr_err("vrfb: no free contexts\n");
        r = -EBUSY;
        goto out;
    }

    DBG("found free ctx %d\n", ctx);

    set_bit(ctx, &ctx_map);

    memset(vrfb, 0, sizeof(*vrfb));

    vrfb->context = ctx;

    for (rot = 0; rot < 4; ++rot) {
        paddr = SMS_ROT_VIRT_BASE(ctx, rot);
        if (!request_mem_region(paddr, OMAP_VRFB_SIZE, "vrfb")) {
            pr_err("vrfb: failed to reserve VRFB "
                    "area for ctx %d, rotation %d\n",
                    ctx, rot * 90);
            omap_vrfb_release_ctx(vrfb);
            r = -ENOMEM;
            goto out;
        }

        vrfb->paddr[rot] = paddr;

        DBG("VRFB %d/%d: %lx\n", ctx, rot*90, vrfb->paddr[rot]);
    }

    r = 0;
out:
    mutex_unlock(&ctx_lock);
    return r;
}
EXPORT_SYMBOL(omap_vrfb_request_ctx);