Commit d463633d63e6 for kernel
commit d463633d63e6aa10384683bf39971a4b00780c56
Author: Miro Kropacek <miro.kropacek@gmail.com>
Date: Thu Aug 20 10:28:37 2026 +1200
fbdev: atafb: Add support for SuperVidel's SuperBlitter
The SuperVidel graphics FPGA includes a hardware blitter (bit block
transfer engine) operating within the SuperVidel DDR2 video RAM.
Two versions of this blitter exist. Later versions (>= 9) of the
SuperVidel firmware support an asynchronous command FIFO, older
versions must be polled for command completion.
Add hardware-accelerated copyarea, fillrect and imageblit fb
operations (falling back to the non-accelerated versions for
anything that exceeds blitter capabilities).
Signed-off-by: Miro Kropacek <miro.kropacek@gmail.com>
Reviewed-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Michael Schmitz <schmitzmic@gmail.com>
Link: https://lists.debian.org/debian-68k/2026/08/msg00000.html
Signed-off-by: Helge Deller <deller@gmx.de>
diff --git a/drivers/video/fbdev/atafb.c b/drivers/video/fbdev/atafb.c
index 388752130c24..5bca34c45cef 100644
--- a/drivers/video/fbdev/atafb.c
+++ b/drivers/video/fbdev/atafb.c
@@ -2303,6 +2303,185 @@ static int ext_detect(struct fb_info *info)
return 1;
}
+/* ------------------- SuperVidel SuperBlitter ---------------------- */
+
+/*
+ * Hardware blitter in the SuperVidel FPGA, operating within SV DDR2 RAM.
+ * FW revision >= 9 provides a command FIFO (async operation); older
+ * revisions are programmed directly with busy-polling.
+ */
+#define SVBLIT_REGS_PHYS 0x80010000
+#define SVBLIT_SRC1 0x58 /* bits 26:0 */
+#define SVBLIT_SRC2 0x5c
+#define SVBLIT_DST 0x60
+#define SVBLIT_COUNT 0x64 /* bytes per line - 1 */
+#define SVBLIT_SRC1_OFFSET 0x68 /* line start to next line start */
+#define SVBLIT_SRC2_OFFSET 0x6c
+#define SVBLIT_DST_OFFSET 0x70
+#define SVBLIT_MASK_AND_LINES 0x74 /* bits 11:0: number of lines */
+#define SVBLIT_CONTROL 0x78 /* bit 0: busy/start, bits 4:1: mode */
+#define SVBLIT_VERSION 0x7c /* bits 9:0: FW revision */
+#define SVBLIT_FIFO 0x80 /* wr: data; rd: bit 0 empty, bit 1 full */
+
+/*
+ * SuperBlitter bug: Instead of declared 2048 bytes, 2032 is the real maximum.
+ */
+#define SVBLIT_MAX_SPAN 2032
+
+static void __iomem *svblit_regs;
+static int svblit_fw;
+
+static inline u32 svblit_rd(unsigned int reg)
+{
+ return __raw_readl(svblit_regs + reg);
+}
+
+static inline void svblit_wr(unsigned int reg, u32 val)
+{
+ __raw_writel(val, svblit_regs + reg);
+}
+
+/* wait until all queued blits have finished */
+static void svblit_wait(void)
+{
+ if (svblit_fw >= 9)
+ /* FIFO empty flag = fewer than 9 longwords queued */
+ while (!(svblit_rd(SVBLIT_FIFO) & 1))
+ cpu_relax();
+ while (svblit_rd(SVBLIT_CONTROL) & 1)
+ cpu_relax();
+}
+
+/*
+ * FW >= 9 queues commands through the 512-longword FIFO: a command is
+ * 9 longwords (registers 0x58..0x78 in order), executed whenever >= 9
+ * words are queued and the blitter is idle. The full flag rises at
+ * >= 500 queued words, so below it there is always room for a whole
+ * command — one flag check per command prevents overflow (dropped
+ * words would desync the 9-word framing until an SV reinit, which is
+ * exactly what overflowing did before this guard existed). Older FW
+ * is programmed directly with busy-polling.
+ *
+ * The line byte count field is 11 bits but see SVBLIT_MAX_SPAN.
+ */
+static void svblit_copy(u32 src, u32 dst, u32 nbytes, u32 src_offset,
+ u32 dst_offset, u32 lines)
+{
+ while (nbytes) {
+ u32 chunk = min(nbytes, SVBLIT_MAX_SPAN);
+
+ if (svblit_fw >= 9) {
+ while (svblit_rd(SVBLIT_FIFO) & 2)
+ cpu_relax();
+ svblit_wr(SVBLIT_FIFO, src);
+ svblit_wr(SVBLIT_FIFO, 0);
+ svblit_wr(SVBLIT_FIFO, dst);
+ svblit_wr(SVBLIT_FIFO, chunk - 1);
+ svblit_wr(SVBLIT_FIFO, src_offset);
+ svblit_wr(SVBLIT_FIFO, 0);
+ svblit_wr(SVBLIT_FIFO, dst_offset);
+ svblit_wr(SVBLIT_FIFO, lines);
+ svblit_wr(SVBLIT_FIFO, 0x01);
+ } else {
+ while (svblit_rd(SVBLIT_CONTROL) & 1)
+ cpu_relax();
+ svblit_wr(SVBLIT_SRC1, src);
+ svblit_wr(SVBLIT_SRC2, 0);
+ svblit_wr(SVBLIT_DST, dst);
+ svblit_wr(SVBLIT_COUNT, chunk - 1);
+ svblit_wr(SVBLIT_SRC1_OFFSET, src_offset);
+ svblit_wr(SVBLIT_SRC2_OFFSET, 0);
+ svblit_wr(SVBLIT_DST_OFFSET, dst_offset);
+ svblit_wr(SVBLIT_MASK_AND_LINES, lines);
+ svblit_wr(SVBLIT_CONTROL, 0x01);
+ }
+
+ src += chunk;
+ dst += chunk;
+ nbytes -= chunk;
+ }
+}
+
+static int svblit_sync(struct fb_info *info)
+{
+ svblit_wait();
+ return 0;
+}
+
+static void svblit_copyarea(struct fb_info *info,
+ const struct fb_copyarea *area)
+{
+ u32 bytespp = info->var.bits_per_pixel / 8;
+ u32 pitch = info->fix.line_length;
+
+ /*
+ * The blitter walks lines in ascending order, so overlapping
+ * moves down/right would read already overwritten data. Those
+ * are rare for fbcon (scrolling backwards); leave them and
+ * oversized areas to the CPU.
+ */
+ if (area->height > 4095 ||
+ area->dy > area->sy ||
+ (area->dy == area->sy && area->dx > area->sx)) {
+ svblit_wait();
+ cfb_copyarea(info, area);
+ return;
+ }
+
+ svblit_copy(external_addr + area->sy * pitch + area->sx * bytespp,
+ external_addr + area->dy * pitch + area->dx * bytespp,
+ area->width * bytespp, pitch, pitch, area->height);
+ /* async: every CPU access to the fb goes through svblit_wait() */
+}
+
+static void svblit_fillrect(struct fb_info *info,
+ const struct fb_fillrect *rect)
+{
+ u32 bytespp = info->var.bits_per_pixel / 8;
+ u32 pitch = info->fix.line_length;
+ u8 *line;
+ u32 pix;
+
+ svblit_wait(); /* the CPU is about to touch the fb */
+
+ if (rect->rop != ROP_COPY || rect->height <= 1 ||
+ rect->height > 4096) {
+ cfb_fillrect(info, rect);
+ return;
+ }
+
+ pix = (info->fix.visual == FB_VISUAL_TRUECOLOR) ?
+ ((u32 *)info->pseudo_palette)[rect->color] : rect->color;
+
+ /* draw the first line with the CPU ... */
+ line = (u8 *)info->screen_base + rect->dy * pitch +
+ rect->dx * bytespp;
+ switch (bytespp) {
+ case 1:
+ memset(line, pix, rect->width);
+ break;
+ case 2:
+ memset16((u16 *)line, pix, rect->width);
+ break;
+ default:
+ memset32((u32 *)line, pix, rect->width);
+ break;
+ }
+
+ /* ... and let the blitter replicate it into the other lines */
+ svblit_copy(external_addr + rect->dy * pitch + rect->dx * bytespp,
+ external_addr + (rect->dy + 1) * pitch +
+ rect->dx * bytespp,
+ rect->width * bytespp, 0, pitch, rect->height - 1);
+}
+
+static void svblit_imageblit(struct fb_info *info,
+ const struct fb_image *image)
+{
+ svblit_wait(); /* CPU rendering must not race queued blits */
+ cfb_imageblit(info, image);
+}
+
#endif /* ATAFB_EXT */
/* ------ This is the same for most hardware types -------- */
@@ -3179,6 +3358,24 @@ static int __init atafb_probe(struct platform_device *pdev)
phys_screen_base = external_addr;
screen_len = external_len & PAGE_MASK;
memset (screen_base, 0, external_len);
+
+ /* framebuffer in SV RAM: enable the SuperBlitter */
+ if (external_addr >= 0xa0000000) {
+ svblit_regs = ioremap(SVBLIT_REGS_PHYS, 0x100);
+ if (svblit_regs) {
+ svblit_fw = svblit_rd(SVBLIT_VERSION) & 0x1ff;
+ atafb_ops.fb_fillrect = svblit_fillrect;
+ atafb_ops.fb_copyarea = svblit_copyarea;
+ atafb_ops.fb_imageblit = svblit_imageblit;
+ atafb_ops.fb_sync = svblit_sync;
+ fb_info->flags |= FBINFO_HWACCEL_COPYAREA |
+ FBINFO_HWACCEL_FILLRECT;
+ dev_info(&pdev->dev,
+ "SuperBlitter enabled, FW revision %d (%s)\n",
+ svblit_fw, svblit_fw >= 9 ?
+ "async FIFO" : "sync");
+ }
+ }
}
#endif /* ATAFB_EXT */