root/drivers/video/fbdev/wmt_ge_rops.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 *  linux/drivers/video/wmt_ge_rops.c
 *
 *  Accelerators for raster operations using WonderMedia Graphics Engine
 *
 *  Copyright (C) 2010 Alexey Charkov <alchark@gmail.com>
 */

#include <linux/export.h>
#include <linux/module.h>
#include <linux/fb.h>
#include <linux/io.h>
#include <linux/platform_device.h>

#include "wmt_ge_rops.h"

#define GE_COMMAND_OFF          0x00
#define GE_DEPTH_OFF            0x04
#define GE_HIGHCOLOR_OFF        0x08
#define GE_ROPCODE_OFF          0x14
#define GE_FIRE_OFF             0x18
#define GE_SRCBASE_OFF          0x20
#define GE_SRCDISPW_OFF         0x24
#define GE_SRCDISPH_OFF         0x28
#define GE_SRCAREAX_OFF         0x2c
#define GE_SRCAREAY_OFF         0x30
#define GE_SRCAREAW_OFF         0x34
#define GE_SRCAREAH_OFF         0x38
#define GE_DESTBASE_OFF         0x3c
#define GE_DESTDISPW_OFF        0x40
#define GE_DESTDISPH_OFF        0x44
#define GE_DESTAREAX_OFF        0x48
#define GE_DESTAREAY_OFF        0x4c
#define GE_DESTAREAW_OFF        0x50
#define GE_DESTAREAH_OFF        0x54
#define GE_PAT0C_OFF            0x88    /* Pattern 0 color */
#define GE_ENABLE_OFF           0xec
#define GE_INTEN_OFF            0xf0
#define GE_STATUS_OFF           0xf8

static void __iomem *regbase;

/* from the spec it seems more like depth than bits per pixel */
static inline unsigned long pixel_to_pat(u32 depth, u32 pixel, struct fb_info *p)
{
        switch (depth) {
        case 1:
                return ~0ul*pixel;
        case 2:
                return ~0ul/3*pixel;
        case 4:
                return ~0ul/15*pixel;
        case 8:
                return ~0ul/255*pixel;
        case 12:
        case 15:
        case 16:
                return ~0ul/0xffff*pixel;
        case 18:
        case 24:
                return 0x1000001ul*pixel;
        case 32:
                return pixel;
        default:
                fb_warn_once(p, "%s: unsupported pixelformat %d\n", __func__, depth);
                return 0;
        }
}

void wmt_ge_fillrect(struct fb_info *p, const struct fb_fillrect *rect)
{
        unsigned long fg, pat;

        if (p->state != FBINFO_STATE_RUNNING)
                return;

        if (p->fix.visual == FB_VISUAL_TRUECOLOR ||
            p->fix.visual == FB_VISUAL_DIRECTCOLOR)
                fg = ((u32 *) (p->pseudo_palette))[rect->color];
        else
                fg = rect->color;

        pat = pixel_to_pat(p->var.bits_per_pixel, fg, p);

        if (p->fbops->fb_sync)
                p->fbops->fb_sync(p);

        writel(p->var.bits_per_pixel == 32 ? 3 :
              (p->var.bits_per_pixel == 8 ? 0 : 1), regbase + GE_DEPTH_OFF);
        writel(p->var.bits_per_pixel == 15 ? 1 : 0, regbase + GE_HIGHCOLOR_OFF);
        writel(p->fix.smem_start, regbase + GE_DESTBASE_OFF);
        writel(p->var.xres_virtual - 1, regbase + GE_DESTDISPW_OFF);
        writel(p->var.yres_virtual - 1, regbase + GE_DESTDISPH_OFF);
        writel(rect->dx, regbase + GE_DESTAREAX_OFF);
        writel(rect->dy, regbase + GE_DESTAREAY_OFF);
        writel(rect->width - 1, regbase + GE_DESTAREAW_OFF);
        writel(rect->height - 1, regbase + GE_DESTAREAH_OFF);

        writel(pat, regbase + GE_PAT0C_OFF);
        writel(1, regbase + GE_COMMAND_OFF);
        writel(rect->rop == ROP_XOR ? 0x5a : 0xf0, regbase + GE_ROPCODE_OFF);
        writel(1, regbase + GE_FIRE_OFF);
}
EXPORT_SYMBOL_GPL(wmt_ge_fillrect);

void wmt_ge_copyarea(struct fb_info *p, const struct fb_copyarea *area)
{
        if (p->state != FBINFO_STATE_RUNNING)
                return;

        if (p->fbops->fb_sync)
                p->fbops->fb_sync(p);

        writel(p->var.bits_per_pixel > 16 ? 3 :
              (p->var.bits_per_pixel > 8 ? 1 : 0), regbase + GE_DEPTH_OFF);

        writel(p->fix.smem_start, regbase + GE_SRCBASE_OFF);
        writel(p->var.xres_virtual - 1, regbase + GE_SRCDISPW_OFF);
        writel(p->var.yres_virtual - 1, regbase + GE_SRCDISPH_OFF);
        writel(area->sx, regbase + GE_SRCAREAX_OFF);
        writel(area->sy, regbase + GE_SRCAREAY_OFF);
        writel(area->width - 1, regbase + GE_SRCAREAW_OFF);
        writel(area->height - 1, regbase + GE_SRCAREAH_OFF);

        writel(p->fix.smem_start, regbase + GE_DESTBASE_OFF);
        writel(p->var.xres_virtual - 1, regbase + GE_DESTDISPW_OFF);
        writel(p->var.yres_virtual - 1, regbase + GE_DESTDISPH_OFF);
        writel(area->dx, regbase + GE_DESTAREAX_OFF);
        writel(area->dy, regbase + GE_DESTAREAY_OFF);
        writel(area->width - 1, regbase + GE_DESTAREAW_OFF);
        writel(area->height - 1, regbase + GE_DESTAREAH_OFF);

        writel(0xcc, regbase + GE_ROPCODE_OFF);
        writel(1, regbase + GE_COMMAND_OFF);
        writel(1, regbase + GE_FIRE_OFF);
}
EXPORT_SYMBOL_GPL(wmt_ge_copyarea);

int wmt_ge_sync(struct fb_info *p)
{
        int loops = 5000000;
        while ((readl(regbase + GE_STATUS_OFF) & 4) && --loops)
                cpu_relax();
        return loops > 0 ? 0 : -EBUSY;
}
EXPORT_SYMBOL_GPL(wmt_ge_sync);

static int wmt_ge_rops_probe(struct platform_device *pdev)
{
        struct resource *res;

        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (res == NULL) {
                dev_err(&pdev->dev, "no I/O memory resource defined\n");
                return -ENODEV;
        }

        /* Only one ROP engine is presently supported. */
        if (unlikely(regbase)) {
                WARN_ON(1);
                return -EBUSY;
        }

        regbase = ioremap(res->start, resource_size(res));
        if (regbase == NULL) {
                dev_err(&pdev->dev, "failed to map I/O memory\n");
                return -EBUSY;
        }

        writel(1, regbase + GE_ENABLE_OFF);
        printk(KERN_INFO "Enabled support for WMT GE raster acceleration\n");

        return 0;
}

static void wmt_ge_rops_remove(struct platform_device *pdev)
{
        iounmap(regbase);
}

static const struct of_device_id wmt_dt_ids[] = {
        { .compatible = "wm,prizm-ge-rops", },
        { /* sentinel */ }
};

static struct platform_driver wmt_ge_rops_driver = {
        .probe          = wmt_ge_rops_probe,
        .remove         = wmt_ge_rops_remove,
        .driver         = {
                .name   = "wmt_ge_rops",
                .of_match_table = wmt_dt_ids,
        },
};

module_platform_driver(wmt_ge_rops_driver);

MODULE_AUTHOR("Alexey Charkov <alchark@gmail.com>");
MODULE_DESCRIPTION("Accelerators for raster operations using "
                   "WonderMedia Graphics Engine");
MODULE_DEVICE_TABLE(of, wmt_dt_ids);