* [PATCH v2 3/5] fbdev: Add support for further video bit depths on atafb:external
[not found] <20260816073752.16656-1-schmitzmic@gmail.com>
2026-08-16 7:37 ` [PATCH v2 2/5] fbdev: Give atafb proper parent Michael Schmitz
@ 2026-08-16 7:37 ` Michael Schmitz
2026-08-16 7:37 ` [PATCH v2 4/5] fbdev: Add support for SuperVidel's SuperBlitter Michael Schmitz
2 siblings, 0 replies; 3+ messages in thread
From: Michael Schmitz @ 2026-08-16 7:37 UTC (permalink / raw)
To: linux-m68k, geert; +Cc: schmitzmic, Miro Kropacek, linux-fbdev
From: Miro Kropacek <miro.kropacek@gmail.com>
Supervidel offers additional video bit depths (8-bit chunky, 16-bit
RGB565 (also on the originaln Videl) and ARGB888.
Add code to support these bit depths.
Signed-off-by: Miro Kropacek <miro.kropacek@gmail.com>
Reviewed-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Michael Schmitz <schmitzmic@gmail.com>
Cc: <linux-fbdev@vger.kernel.org>
Link: https://lists.debian.org/debian-68k/2026/08/msg00000.html
---
drivers/video/fbdev/atafb.c | 89 ++++++++++++++++++++++++++++++++++---
1 file changed, 82 insertions(+), 7 deletions(-)
diff --git a/drivers/video/fbdev/atafb.c b/drivers/video/fbdev/atafb.c
index 3d540803dc2b..50853d7a08e3 100644
--- a/drivers/video/fbdev/atafb.c
+++ b/drivers/video/fbdev/atafb.c
@@ -2081,8 +2081,12 @@ static int ext_encode_fix(struct fb_fix_screeninfo *fix, struct atafb_par *par)
external_pmode == FB_TYPE_PACKED_PIXELS) ?
FB_VISUAL_MONO10 : FB_VISUAL_MONO01;
} else {
- /* Use STATIC if we don't know how to access color registers */
- int visual = external_vgaiobase ?
+ /* Use STATIC if we don't know how to access color registers;
+ * SuperVidel 8bpp chunky (fb in SV RAM) uses the Falcon palette
+ */
+ int visual = (external_vgaiobase ||
+ (external_depth == 8 &&
+ external_addr >= 0xa0000000)) ?
FB_VISUAL_PSEUDOCOLOR :
FB_VISUAL_STATIC_PSEUDOCOLOR;
switch (external_pmode) {
@@ -2159,6 +2163,35 @@ static int ext_encode_var(struct fb_var_screeninfo *var, struct atafb_par *par)
var->transp.offset = 0;
var->transp.length = 0;
var->transp.msb_right = 0;
+ if (external_pmode == -1 && external_depth == 16) {
+ /* RGB565 truecolor (e.g. SuperVidel native mode) */
+ var->red.offset = 11;
+ var->red.length = 5;
+ var->green.offset = 5;
+ var->green.length = 6;
+ var->blue.offset = 0;
+ var->blue.length = 5;
+ } else if (external_pmode == -1 && external_depth == 32) {
+ /* ARGB8888 truecolor (e.g. SuperVidel native mode) */
+ var->red.offset = 16;
+ var->red.length = 8;
+ var->green.offset = 8;
+ var->green.length = 8;
+ var->blue.offset = 0;
+ var->blue.length = 8;
+ var->transp.offset = 24;
+ var->transp.length = 8;
+ } else if (external_pmode == FB_TYPE_PACKED_PIXELS &&
+ external_depth == 8 && external_addr >= 0xa0000000) {
+ /* SuperVidel 8bpp chunky: palette has 8 bits per channel.
+ * Without this, fb_get_color_depth() sees length 0 and
+ * fbcon falls back to its 2-color palette — the console
+ * text (color 7) stays black on black.
+ */
+ var->red.length = 8;
+ var->green.length = 8;
+ var->blue.length = 8;
+ }
var->yres_virtual = var->yres;
var->xoffset = 0;
var->yoffset = 0;
@@ -2193,6 +2226,38 @@ static int ext_setcolreg(unsigned int regno, unsigned int red,
{
unsigned char colmask = (1 << external_bitspercol) - 1;
+ if (external_pmode == -1 && external_depth == 16) {
+ /* truecolor: only the pseudo palette for fbcon is needed */
+ if (regno > 15)
+ return 1;
+ ((u32 *)info->pseudo_palette)[regno] = (red & 0xf800) |
+ ((green & 0xfc00) >> 5) |
+ ((blue & 0xf800) >> 11);
+ return 0;
+ }
+ if (external_pmode == -1 && external_depth == 32) {
+ /* ARGB8888, alpha forced opaque */
+ if (regno > 15)
+ return 1;
+ ((u32 *)info->pseudo_palette)[regno] = 0xff000000 |
+ ((red & 0xff00) << 8) |
+ (green & 0xff00) |
+ ((blue & 0xff00) >> 8);
+ return 0;
+ }
+ if (external_pmode == FB_TYPE_PACKED_PIXELS && external_depth == 8 &&
+ external_addr >= 0xa0000000) {
+ /* SuperVidel native 8bpp chunky scans out via the Falcon
+ * palette registers, honoring all 8 bits per channel
+ */
+ if (regno > 255)
+ return 1;
+ f030_col[regno] = ((red & 0xff00) << 16) |
+ ((green & 0xff00) << 8) |
+ ((blue & 0xff00) >> 8);
+ return 0;
+ }
+
if (!external_vgaiobase)
return 1;
@@ -2422,7 +2487,9 @@ static void atafb_fillrect(struct fb_info *info, const struct fb_fillrect *rect)
return;
#ifdef ATAFB_FALCON
- if (info->var.bits_per_pixel == 16) {
+ /* chunky modes (Falcon hicolor, external packed/truecolor) */
+ if (info->fix.type == FB_TYPE_PACKED_PIXELS &&
+ info->var.bits_per_pixel > 1) {
cfb_fillrect(info, rect);
return;
}
@@ -2463,7 +2530,9 @@ static void atafb_copyarea(struct fb_info *info, const struct fb_copyarea *area)
int rev_copy = 0;
#ifdef ATAFB_FALCON
- if (info->var.bits_per_pixel == 16) {
+ /* chunky modes (Falcon hicolor, external packed/truecolor) */
+ if (info->fix.type == FB_TYPE_PACKED_PIXELS &&
+ info->var.bits_per_pixel > 1) {
cfb_copyarea(info, area);
return;
}
@@ -2517,7 +2586,9 @@ static void atafb_imageblit(struct fb_info *info, const struct fb_image *image)
u32 dx, dy, width, height, pitch;
#ifdef ATAFB_FALCON
- if (info->var.bits_per_pixel == 16) {
+ /* chunky modes (Falcon hicolor, external packed/truecolor) */
+ if (info->fix.type == FB_TYPE_PACKED_PIXELS &&
+ info->var.bits_per_pixel > 1) {
cfb_imageblit(info, image);
return;
}
@@ -2753,7 +2824,7 @@ static void __init atafb_setup_ext(char *spec)
return;
depth = simple_strtoul(p, NULL, 10);
if (depth != 1 && depth != 2 && depth != 4 && depth != 8 &&
- depth != 16 && depth != 24)
+ depth != 16 && depth != 24 && depth != 32)
return;
p = strsep(&spec, ";");
@@ -3131,7 +3202,11 @@ static int __init atafb_probe(struct platform_device *pdev)
atafb_set_disp(&fb_info);
- fb_alloc_cmap(&(fb_info.cmap), 1 << fb_info.var.bits_per_pixel, 0);
+ /* truecolor visuals only need the 16-entry console palette; this
+ * also avoids 1 << 32 overflowing at 32bpp
+ */
+ fb_alloc_cmap(&(fb_info.cmap), fb_info.var.bits_per_pixel > 8 ?
+ 16 : 1 << fb_info.var.bits_per_pixel, 0);
dev_info(&pdev->dev, "Determined %dx%d, depth %d\n", fb_info.var.xres,
--
2.17.1
^ permalink raw reply related [flat|nested] 3+ messages in thread* [PATCH v2 4/5] fbdev: Add support for SuperVidel's SuperBlitter
[not found] <20260816073752.16656-1-schmitzmic@gmail.com>
2026-08-16 7:37 ` [PATCH v2 2/5] fbdev: Give atafb proper parent Michael Schmitz
2026-08-16 7:37 ` [PATCH v2 3/5] fbdev: Add support for further video bit depths on atafb:external Michael Schmitz
@ 2026-08-16 7:37 ` Michael Schmitz
2 siblings, 0 replies; 3+ messages in thread
From: Michael Schmitz @ 2026-08-16 7:37 UTC (permalink / raw)
To: linux-m68k, geert; +Cc: schmitzmic, Miro Kropacek, linux-fbdev
From: Miro Kropacek <miro.kropacek@gmail.com>
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>
Cc: <linux-fbdev@vger.kernel.org>
Link: https://lists.debian.org/debian-68k/2026/08/msg00000.html
---
drivers/video/fbdev/atafb.c | 197 ++++++++++++++++++++++++++++++++++++
1 file changed, 197 insertions(+)
diff --git a/drivers/video/fbdev/atafb.c b/drivers/video/fbdev/atafb.c
index 50853d7a08e3..dc2d4154e1b6 100644
--- a/drivers/video/fbdev/atafb.c
+++ b/drivers/video/fbdev/atafb.c
@@ -2304,6 +2304,185 @@ static int ext_detect(void)
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 -------- */
@@ -3168,6 +3347,24 @@ 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 */
--
2.17.1
^ permalink raw reply related [flat|nested] 3+ messages in thread