* [PATCH v3 2/5] fbdev: Give atafb proper parent
2026-08-19 22:28 [PATCH v3 0/5] m68k SuperVidel patches Michael Schmitz
@ 2026-08-19 22:28 ` Michael Schmitz
2026-08-19 22:28 ` [PATCH v3 3/5] fbdev: Add support for further video bit depths on atafb:external Michael Schmitz
2026-08-19 22:28 ` [PATCH v3 4/5] fbdev: Add support for SuperVidel's SuperBlitter Michael Schmitz
2 siblings, 0 replies; 4+ messages in thread
From: Michael Schmitz @ 2026-08-19 22:28 UTC (permalink / raw)
To: linux-m68k, geert; +Cc: schmitzmic, Miro Kropacek, linux-fbdev
From: Miro Kropacek <miro.kropacek@gmail.com>
The atafb fb device registers no parent, causing a missing symlink
(/sys/class/graphics/fb0/device). Xorg fbdevhw driver looks for that
symlink when scanning for devices, so add a parent node for atafb.
The proper way to do that is use of framebuffer_alloc(), which
requries refactoring atafb to move from static fb_info to allocation
of fb_info by framebuffer_alloc().
About the only location where a fb_info pointer cannot be passed
is monspec setup in atafb_setup(). Store static monspecs there
and copy into place after framebuffer_alloc().
Pass fb_info everywhere it's needed (detect, decode_var and
do_fb_set_var functions), and remove the static fb_info struct.
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
---
Changes in v3:
- fbdev: refactor atafb fb_info use to allow use of framebuffer_alloc()
(Thomas Zimmermann)
---
drivers/video/fbdev/atafb.c | 174 +++++++++++++++++++-----------------
1 file changed, 92 insertions(+), 82 deletions(-)
diff --git a/drivers/video/fbdev/atafb.c b/drivers/video/fbdev/atafb.c
index b8ed1c537293..a9be06ded5c9 100644
--- a/drivers/video/fbdev/atafb.c
+++ b/drivers/video/fbdev/atafb.c
@@ -158,14 +158,6 @@ static int DontCalcRes = 0;
#define VMO_PREMASK 0x0c
#endif
-static struct fb_info fb_info = {
- .fix = {
- .id = "Atari ",
- .visual = FB_VISUAL_PSEUDOCOLOR,
- .accel = FB_ACCEL_NONE,
- }
-};
-
static void *screen_base; /* base address of screen */
static unsigned long phys_screen_base; /* (only for Overscan) */
@@ -175,6 +167,12 @@ static int current_par_valid;
static int mono_moni;
+/* monspecs passed by user */
+
+static __u32 mcap_hmin; /* hfreq lower limit (Hz) */
+static __u32 mcap_hmax; /* hfreq upper limit (Hz) */
+static __u16 mcap_vmin; /* vfreq lower limit (Hz) */
+static __u16 mcap_vmax; /* vfreq upper limit (Hz) */
#ifdef ATAFB_EXT
@@ -299,7 +297,7 @@ static int *MV300_reg = MV300_reg_8bit;
/* ++roman: This structure abstracts from the underlying hardware (ST(e),
* TT, or Falcon.
*
- * int (*detect)(void)
+ * int (*detect)(*fb_info)
* This function should detect the current video mode settings and
* store them in atafb_predefined[0] for later reference by the
* user. Return the index+1 of an equivalent predefined mode or 0
@@ -311,7 +309,7 @@ static int *MV300_reg = MV300_reg_8bit;
* values in the 'par' structure.
* !!! Obsolete, perhaps !!!
*
- * int (*decode_var)(struct fb_var_screeninfo *var,
+ * int (*decode_var)(struct fb_info *info, struct fb_var_screeninfo *var,
* struct atafb_par *par)
* Get the video params out of 'var'. If a value doesn't fit, round
* it up, if it's too big, return EINVAL.
@@ -345,10 +343,10 @@ static int *MV300_reg = MV300_reg_8bit;
*/
static struct fb_hwswitch {
- int (*detect)(void);
+ int (*detect)(struct fb_info *info);
int (*encode_fix)(struct fb_fix_screeninfo *fix,
struct atafb_par *par);
- int (*decode_var)(struct fb_var_screeninfo *var,
+ int (*decode_var)(struct fb_info *info, struct fb_var_screeninfo *var,
struct atafb_par *par);
int (*encode_var)(struct fb_var_screeninfo *var,
struct atafb_par *par);
@@ -576,7 +574,7 @@ static int tt_encode_fix(struct fb_fix_screeninfo *fix, struct atafb_par *par)
return 0;
}
-static int tt_decode_var(struct fb_var_screeninfo *var, struct atafb_par *par)
+static int tt_decode_var(struct fb_info *info, struct fb_var_screeninfo *var, struct atafb_par *par)
{
int xres = var->xres;
int yres = var->yres;
@@ -782,7 +780,7 @@ static int tt_setcolreg(unsigned int regno, unsigned int red,
return 0;
}
-static int tt_detect(void)
+static int tt_detect(struct fb_info *info)
{
struct atafb_par par;
@@ -877,7 +875,7 @@ static int falcon_encode_fix(struct fb_fix_screeninfo *fix,
return 0;
}
-static int falcon_decode_var(struct fb_var_screeninfo *var,
+static int falcon_decode_var(struct fb_info *info, struct fb_var_screeninfo *var,
struct atafb_par *par)
{
int bpp = var->bits_per_pixel;
@@ -1069,13 +1067,13 @@ static int falcon_decode_var(struct fb_var_screeninfo *var,
/* Choose master pixelclock depending on hor. timing */
plen = 1 * xstretch;
if ((plen * xres + f25.right + f25.hsync + f25.left) *
- fb_info.monspecs.hfmin < f25.f)
+ info->monspecs.hfmin < f25.f)
pclock = &f25;
else if ((plen * xres + f32.right + f32.hsync +
- f32.left) * fb_info.monspecs.hfmin < f32.f)
+ f32.left) * info->monspecs.hfmin < f32.f)
pclock = &f32;
else if ((plen * xres + fext.right + fext.hsync +
- fext.left) * fb_info.monspecs.hfmin < fext.f &&
+ fext.left) * info->monspecs.hfmin < fext.f &&
fext.f)
pclock = &fext;
else
@@ -1245,14 +1243,14 @@ static int falcon_decode_var(struct fb_var_screeninfo *var,
/* check hor. frequency */
hfreq = pclock->f / ((par->HHT + 2) * prescale * 2);
- if (hfreq > fb_info.monspecs.hfmax && mon_type != F_MON_VGA) {
+ if (hfreq > info->monspecs.hfmax && mon_type != F_MON_VGA) {
/* ++guenther: ^^^^^^^^^^^^^^^^^^^ can't remember why I did this */
/* Too high -> enlarge margin */
left_margin += 1;
right_margin += 1;
goto again;
}
- if (hfreq > fb_info.monspecs.hfmax || hfreq < fb_info.monspecs.hfmin)
+ if (hfreq > info->monspecs.hfmax || hfreq < info->monspecs.hfmin)
return -EINVAL;
/* Vxx-registers */
@@ -1283,50 +1281,50 @@ static int falcon_decode_var(struct fb_var_screeninfo *var,
/* V-frequency check, hope I didn't create any loop here. */
/* Interlace and doubleline are mutually exclusive. */
vfreq = (hfreq * 2) / (par->VFT + 1);
- if (vfreq > fb_info.monspecs.vfmax && !doubleline && !interlace) {
+ if (vfreq > info->monspecs.vfmax && !doubleline && !interlace) {
/* Too high -> try again with doubleline */
doubleline = 1;
goto again;
- } else if (vfreq < fb_info.monspecs.vfmin && !interlace && !doubleline) {
+ } else if (vfreq < info->monspecs.vfmin && !interlace && !doubleline) {
/* Too low -> try again with interlace */
interlace = 1;
goto again;
- } else if (vfreq < fb_info.monspecs.vfmin && doubleline) {
+ } else if (vfreq < info->monspecs.vfmin && doubleline) {
/* Doubleline too low -> clear doubleline and enlarge margins */
int lines;
doubleline = 0;
for (lines = 0;
(hfreq * 2) / (par->VFT + 1 + 4 * lines - 2 * yres) >
- fb_info.monspecs.vfmax;
+ info->monspecs.vfmax;
lines++)
;
upper_margin += lines;
lower_margin += lines;
goto again;
- } else if (vfreq > fb_info.monspecs.vfmax && doubleline) {
+ } else if (vfreq > info->monspecs.vfmax && doubleline) {
/* Doubleline too high -> enlarge margins */
int lines;
for (lines = 0;
(hfreq * 2) / (par->VFT + 1 + 4 * lines) >
- fb_info.monspecs.vfmax;
+ info->monspecs.vfmax;
lines += 2)
;
upper_margin += lines;
lower_margin += lines;
goto again;
- } else if (vfreq > fb_info.monspecs.vfmax && interlace) {
+ } else if (vfreq > info->monspecs.vfmax && interlace) {
/* Interlace, too high -> enlarge margins */
int lines;
for (lines = 0;
(hfreq * 2) / (par->VFT + 1 + 4 * lines) >
- fb_info.monspecs.vfmax;
+ info->monspecs.vfmax;
lines++)
;
upper_margin += lines;
lower_margin += lines;
goto again;
- } else if (vfreq < fb_info.monspecs.vfmin ||
- vfreq > fb_info.monspecs.vfmax)
+ } else if (vfreq < info->monspecs.vfmin ||
+ vfreq > info->monspecs.vfmax)
return -EINVAL;
set_screen_base:
@@ -1720,7 +1718,7 @@ static int falcon_blank(int blank_mode)
return 0;
}
-static int falcon_detect(void)
+static int falcon_detect(struct fb_info *info)
{
struct atafb_par par;
unsigned char fhw;
@@ -1732,18 +1730,18 @@ static int falcon_detect(void)
f030_bus_width = fhw << 6 & 0x80;
switch (mon_type) {
case F_MON_SM:
- fb_info.monspecs.vfmin = 70;
- fb_info.monspecs.vfmax = 72;
- fb_info.monspecs.hfmin = 35713;
- fb_info.monspecs.hfmax = 35715;
+ info->monspecs.vfmin = 70;
+ info->monspecs.vfmax = 72;
+ info->monspecs.hfmin = 35713;
+ info->monspecs.hfmax = 35715;
break;
case F_MON_SC:
case F_MON_TV:
/* PAL...NTSC */
- fb_info.monspecs.vfmin = 49; /* not 50, since TOS defaults to 49.9x Hz */
- fb_info.monspecs.vfmax = 60;
- fb_info.monspecs.hfmin = 15620;
- fb_info.monspecs.hfmax = 15755;
+ info->monspecs.vfmin = 49; /* not 50, since TOS defaults to 49.9x Hz */
+ info->monspecs.vfmax = 60;
+ info->monspecs.hfmin = 15620;
+ info->monspecs.hfmax = 15755;
break;
}
/* initialize hsync-len */
@@ -1795,7 +1793,7 @@ static int stste_encode_fix(struct fb_fix_screeninfo *fix,
return 0;
}
-static int stste_decode_var(struct fb_var_screeninfo *var,
+static int stste_decode_var(struct fb_info *info, struct fb_var_screeninfo *var,
struct atafb_par *par)
{
int xres = var->xres;
@@ -1971,7 +1969,7 @@ static int stste_setcolreg(unsigned int regno, unsigned int red,
return 0;
}
-static int stste_detect(void)
+static int stste_detect(struct fb_info *info)
{
struct atafb_par par;
@@ -2112,7 +2110,8 @@ static int ext_encode_fix(struct fb_fix_screeninfo *fix, struct atafb_par *par)
return 0;
}
-static int ext_decode_var(struct fb_var_screeninfo *var, struct atafb_par *par)
+static int ext_decode_var(struct fb_info *info, struct fb_var_screeninfo *var,
+ struct atafb_par *par)
{
struct fb_var_screeninfo *myvar = &atafb_predefined[0];
@@ -2226,7 +2225,7 @@ static int ext_setcolreg(unsigned int regno, unsigned int red,
}
}
-static int ext_detect(void)
+static int ext_detect(struct fb_info *info)
{
struct fb_var_screeninfo *myvar = &atafb_predefined[0];
struct atafb_par dummy_par;
@@ -2344,12 +2343,12 @@ static void ata_set_par(struct atafb_par *par)
/* used for hardware scrolling */
-static int do_fb_set_var(struct fb_var_screeninfo *var, int isactive)
+static int do_fb_set_var(struct fb_info *info, struct fb_var_screeninfo *var, int isactive)
{
int err, activate;
struct atafb_par par;
- err = fbhw->decode_var(var, &par);
+ err = fbhw->decode_var(info, var, &par);
if (err)
return err;
activate = var->activate;
@@ -2368,7 +2367,7 @@ static int atafb_get_fix(struct fb_fix_screeninfo *fix, struct fb_info *info)
struct atafb_par par;
int err;
// Get fix directly (case con == -1 before)??
- err = fbhw->decode_var(&info->var, &par);
+ err = fbhw->decode_var(info, &info->var, &par);
if (err)
return err;
memset(fix, 0, sizeof(struct fb_fix_screeninfo));
@@ -2635,7 +2634,7 @@ static int atafb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
/* Validate wanted screen parameters */
// if ((err = ata_decode_var(var, &par)))
- err = fbhw->decode_var(var, &par);
+ err = fbhw->decode_var(info, var, &par);
if (err)
return err;
@@ -2651,7 +2650,7 @@ static int atafb_set_par(struct fb_info *info)
struct atafb_par *par = info->par;
/* Decode wanted screen parameters */
- fbhw->decode_var(&info->var, par);
+ fbhw->decode_var(info, &info->var, par);
mutex_lock(&info->mm_lock);
fbhw->encode_fix(&info->fix, par);
mutex_unlock(&info->mm_lock);
@@ -2677,7 +2676,7 @@ static struct fb_ops atafb_ops = {
__FB_DEFAULT_IOMEM_OPS_MMAP,
};
-static void check_default_par(int detected_mode)
+static void check_default_par(struct fb_info *info, int detected_mode)
{
char default_name[10];
int i;
@@ -2688,14 +2687,14 @@ static void check_default_par(int detected_mode)
if (default_par) {
var = atafb_predefined[default_par - 1];
var.activate = FB_ACTIVATE_TEST;
- if (do_fb_set_var(&var, 1))
+ if (do_fb_set_var(info, &var, 1))
default_par = 0; /* failed */
}
/* Next is the autodetected one */
if (!default_par) {
var = atafb_predefined[detected_mode - 1]; /* autodetect */
var.activate = FB_ACTIVATE_TEST;
- if (!do_fb_set_var(&var, 1))
+ if (!do_fb_set_var(info, &var, 1))
default_par = detected_mode;
}
/* If that also failed, try some default modes... */
@@ -2708,7 +2707,7 @@ static void check_default_par(int detected_mode)
panic("can't set default video mode");
var = atafb_predefined[default_par - 1];
var.activate = FB_ACTIVATE_TEST;
- if (!do_fb_set_var(&var,1))
+ if (!do_fb_set_var(info, &var, 1))
break; /* ok */
}
}
@@ -2901,10 +2900,10 @@ static void __init atafb_setup_mcap(char *spec)
if (hmax <= 0 || hmax <= hmin)
return;
- fb_info.monspecs.vfmin = vmin;
- fb_info.monspecs.vfmax = vmax;
- fb_info.monspecs.hfmin = hmin;
- fb_info.monspecs.hfmax = hmax;
+ mcap_vmin = vmin;
+ mcap_vmax = vmax;
+ mcap_hmin = hmin;
+ mcap_hmax = hmax;
}
#endif /* ATAFB_FALCON */
@@ -2991,12 +2990,19 @@ static int __init atafb_probe(struct platform_device *pdev)
unsigned int defmode = 0;
unsigned long mem_req;
char *option = NULL;
+ struct fb_info *fb_info;
if (fb_get_options("atafb", &option))
return -ENODEV;
atafb_setup(option);
dev_dbg(&pdev->dev, "%s: start\n", __func__);
+ fb_info = framebuffer_alloc(sizeof(struct atafb_par), &pdev->dev);
+
+ strscpy(fb_info->fix.id, "Atari ");
+ fb_info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
+ fb_info->fix.accel = FB_ACCEL_NONE;
+
do {
#ifdef ATAFB_EXT
if (external_addr) {
@@ -3052,15 +3058,20 @@ static int __init atafb_probe(struct platform_device *pdev)
/* Multisync monitor capabilities */
/* Atari-TOS defaults if no boot option present */
- if (fb_info.monspecs.hfmin == 0) {
- fb_info.monspecs.hfmin = 31000;
- fb_info.monspecs.hfmax = 32000;
- fb_info.monspecs.vfmin = 58;
- fb_info.monspecs.vfmax = 62;
+ if (mcap_hmin == 0) {
+ fb_info->monspecs.hfmin = 31000;
+ fb_info->monspecs.hfmax = 32000;
+ fb_info->monspecs.vfmin = 58;
+ fb_info->monspecs.vfmax = 62;
+ } else {
+ fb_info->monspecs.vfmin = mcap_vmin;
+ fb_info->monspecs.vfmax = mcap_vmax;
+ fb_info->monspecs.hfmin = mcap_hmin;
+ fb_info->monspecs.hfmax = mcap_hmax;
}
- detected_mode = fbhw->detect();
- check_default_par(detected_mode);
+ detected_mode = fbhw->detect(fb_info);
+ check_default_par(fb_info, detected_mode);
#ifdef ATAFB_EXT
if (!external_addr) {
#endif /* ATAFB_EXT */
@@ -3100,43 +3111,42 @@ static int __init atafb_probe(struct platform_device *pdev)
}
#endif /* ATAFB_EXT */
-// strcpy(fb_info.mode->name, "Atari Builtin ");
- fb_info.fbops = &atafb_ops;
+// strcpy(fb_info->mode->name, "Atari Builtin ");
+ fb_info->fbops = &atafb_ops;
// try to set default (detected; requested) var
- do_fb_set_var(&atafb_predefined[default_par - 1], 1);
+ do_fb_set_var(fb_info, &atafb_predefined[default_par - 1], 1);
// reads hw state into current par, which may not be sane yet
ata_get_par(¤t_par);
- fb_info.par = ¤t_par;
+ fb_info->par = ¤t_par;
// tries to read from HW which may not be initialized yet
// so set sane var first, then call atafb_set_par
- atafb_get_var(&fb_info.var, &fb_info);
+ atafb_get_var(&(fb_info->var), fb_info);
#ifdef ATAFB_FALCON
- fb_info.pseudo_palette = current_par.hw.falcon.pseudo_palette;
+ fb_info->pseudo_palette = current_par.hw.falcon.pseudo_palette;
#endif
- if (!fb_find_mode(&fb_info.var, &fb_info, mode_option, atafb_modedb,
+ if (!fb_find_mode(&(fb_info->var), fb_info, mode_option, atafb_modedb,
NUM_TOTAL_MODES, &atafb_modedb[defmode],
- fb_info.var.bits_per_pixel)) {
+ fb_info->var.bits_per_pixel)) {
return -EINVAL;
}
fb_videomode_to_modelist(atafb_modedb, NUM_TOTAL_MODES,
- &fb_info.modelist);
-
- atafb_set_disp(&fb_info);
+ &(fb_info->modelist));
- fb_alloc_cmap(&(fb_info.cmap), 1 << fb_info.var.bits_per_pixel, 0);
+ atafb_set_disp(fb_info);
+ fb_alloc_cmap(&(fb_info->cmap), 1 << fb_info->var.bits_per_pixel, 0);
- dev_info(&pdev->dev, "Determined %dx%d, depth %d\n", fb_info.var.xres,
- fb_info.var.yres, fb_info.var.bits_per_pixel);
- if ((fb_info.var.xres != fb_info.var.xres_virtual) ||
- (fb_info.var.yres != fb_info.var.yres_virtual))
+ dev_info(&pdev->dev, "Determined %dx%d, depth %d\n", fb_info->var.xres,
+ fb_info->var.yres, fb_info->var.bits_per_pixel);
+ if ((fb_info->var.xres != fb_info->var.xres_virtual) ||
+ (fb_info->var.yres != fb_info->var.yres_virtual))
dev_info(&pdev->dev, " virtual %dx%d\n",
- fb_info.var.xres_virtual, fb_info.var.yres_virtual);
+ fb_info->var.xres_virtual, fb_info->var.yres_virtual);
- if (register_framebuffer(&fb_info) < 0) {
+ if (register_framebuffer(fb_info) < 0) {
#ifdef ATAFB_EXT
if (external_addr) {
iounmap(external_screen_base);
@@ -3150,7 +3160,7 @@ static int __init atafb_probe(struct platform_device *pdev)
return -EINVAL;
}
- fb_info(&fb_info, "frame buffer device, using %dK of video memory\n",
+ fb_info(fb_info, "frame buffer device, using %dK of video memory\n",
screen_len >> 10);
/* TODO: This driver cannot be unloaded yet */
--
2.17.1
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH v3 3/5] fbdev: Add support for further video bit depths on atafb:external
2026-08-19 22:28 [PATCH v3 0/5] m68k SuperVidel patches Michael Schmitz
2026-08-19 22:28 ` [PATCH v3 2/5] fbdev: Give atafb proper parent Michael Schmitz
@ 2026-08-19 22:28 ` Michael Schmitz
2026-08-19 22:28 ` [PATCH v3 4/5] fbdev: Add support for SuperVidel's SuperBlitter Michael Schmitz
2 siblings, 0 replies; 4+ messages in thread
From: Michael Schmitz @ 2026-08-19 22:28 UTC (permalink / raw)
To: linux-m68k, geert; +Cc: schmitzmic, Miro Kropacek, linux-fbdev
[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain; charset=y, Size: 6007 bytes --]
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
---
Changes in v3:
- adapt patch to fb_info -> *fb_info rewrite (in patch 2)
---
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 a9be06ded5c9..1a245141560b 100644
--- a/drivers/video/fbdev/atafb.c
+++ b/drivers/video/fbdev/atafb.c
@@ -2079,8 +2079,12 @@ 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) {
@@ -2158,6 +2162,35 @@ 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;
@@ -2192,6 +2225,38 @@ 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;
@@ -2421,7 +2486,9 @@ 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;
}
@@ -2462,7 +2529,9 @@ 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;
}
@@ -2516,7 +2585,9 @@ 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;
}
@@ -2752,7 +2823,7 @@ 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, ";");
@@ -3137,7 +3208,11 @@ 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,
fb_info->var.yres, fb_info->var.bits_per_pixel);
--
2.17.1
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH v3 4/5] fbdev: Add support for SuperVidel's SuperBlitter
2026-08-19 22:28 [PATCH v3 0/5] m68k SuperVidel patches Michael Schmitz
2026-08-19 22:28 ` [PATCH v3 2/5] fbdev: Give atafb proper parent Michael Schmitz
2026-08-19 22:28 ` [PATCH v3 3/5] fbdev: Add support for further video bit depths on atafb:external Michael Schmitz
@ 2026-08-19 22:28 ` Michael Schmitz
2 siblings, 0 replies; 4+ messages in thread
From: Michael Schmitz @ 2026-08-19 22:28 UTC (permalink / raw)
To: linux-m68k, geert; +Cc: schmitzmic, Miro Kropacek, linux-fbdev
[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain; charset=y, Size: 7686 bytes --]
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
---
Changes in v3:
- adapt patch to fb_info -> *fb_info rewrite (in patch 2)
---
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 1a245141560b..1e5724d99b39 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 */
--
2.17.1
^ permalink raw reply related [flat|nested] 4+ messages in thread