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[096/120] MIPS: PS2: FB: fb_set_par() high-definition television support

Message ID 95af9f78f8336db3170ae66218af33e3ccfaea50.1567326213.git.noring@nocrew.org (mailing list archive)
State RFC
Headers show
Series Linux for the PlayStation 2 | expand

Commit Message

Fredrik Noring Sept. 1, 2019, 4:30 p.m. UTC
Some of the numeric register field constants come from fixed DTV video
modes made by Sony[1]. The main complication is that these values are
the basis to compute arbitrary top, bottom, left and right display
margin (border) settings. This is useful to for example precisely
center the image for a given analogue video display.

The HDTV modes are designed to work with component video cables and the
PS2 HDMI adapter based on the Macro Silicon MS9282 chip.

The MAGV and MAGH fields for vertical and horizontal magnification in
the DISPLAY registers could be used to emulate SDTV resolution video
modes such as 320x200 that was popular with many 8-bit and 16-bit
computers, but that is left for a future extension.

References:

[1] "GS User's Manual", version 6.0, Sony Computer Entertainment Inc.,
    p. 84.

Signed-off-by: Fredrik Noring <noring@nocrew.org>
---
 drivers/video/fbdev/ps2fb.c | 86 ++++++++++++++++++++++++++++++++++++-
 1 file changed, 85 insertions(+), 1 deletion(-)
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Patch

diff --git a/drivers/video/fbdev/ps2fb.c b/drivers/video/fbdev/ps2fb.c
index 3fb31719459c..f9061ccc5755 100644
--- a/drivers/video/fbdev/ps2fb.c
+++ b/drivers/video/fbdev/ps2fb.c
@@ -554,10 +554,94 @@  static struct gs_sync_param vm_to_sp_sdtv(const struct fb_videomode *vm)
 	};
 }
 
+/**
+ * vm_to_sp_hdtv - high-definition television video synch parameters
+ * @vm: video mode object to compute synchronisation parameters for
+ * @sg: Graphics Synthesizer SMODE1 register video clock fields
+ *
+ * Some of the numeric register field constants come from fixed DTV video
+ * modes made by Sony. The main complication is that these values are the
+ * basis to compute arbitrary top, bottom, left and right display margin
+ * (border) settings. This is useful to for example precisely center the
+ * image for a given analogue video display.
+ *
+ * The HDTV modes are designed to work with component video cables and the
+ * PS2 HDMI adapter based on the Macro Silicon MS9282 chip.
+ *
+ * The MAGV and MAGH fields for vertical and horizontal magnification in the
+ * DISPLAY registers could be used to emulate SDTV resolution video modes such
+ * as 320x200 that was popular with many 8-bit and 16-bit computers, but that
+ * is left for a future extension.
+ *
+ * Return: Graphics Synthesizer HDTV video mode synchronisation parameters
+ */
+static struct gs_sync_param vm_to_sp_hdtv(
+	const struct fb_videomode *vm, const struct gs_synch_gen sg)
+{
+	const u32 spml  = sg.spml;
+	const u32 t1248 = sg.t1248;
+	const u32 lc    = sg.lc;
+	const u32 rc    = sg.rc;
+	const u32 vc    = vm->yres <= 576 ? 1 : 0;
+	const u32 hadj  = spml / 2;
+	const u32 vhp   = (vm->vmode & FB_VMODE_INTERLACED) ? 0 : 1;
+	const u32 hb    = vm->xres * spml * 3 / 5;
+
+	return (struct gs_sync_param) {
+		.smode1 = {
+			.vhp    = vhp, .vcksel = vc, .slck2 =     1, .nvck = 1,
+			.clksel =   1, .pevs   =  0, .pehs  =     0, .pvs  = 0,
+			.phs    =   0, .gcont  =  0, .spml  =  spml, .pck2 = 0,
+			.xpck   =   0, .sint   =  1, .prst  =     0, .ex   = 0,
+			.cmod   =   0, .slck   =  0, .t1248 = t1248,
+			.lc     =  lc, .rc     = rc
+		},
+		.smode2 = {
+			.intm = (vm->vmode & FB_VMODE_INTERLACED) ? 1 : 0
+		},
+		.srfsh = {
+			.rfsh = gs_rfsh_from_synch_gen(sg)
+		},
+		.synch1 = {
+			.hs   = vm->hsync_len * spml,
+			.hsvs = (vm->left_margin + vm->xres +
+				 vm->right_margin - vm->hsync_len) * spml / 2,
+			.hseq = vm->hsync_len * spml,
+			.hbp  = vm->left_margin * spml - hadj,
+			.hfp  = vm->right_margin * spml + hadj
+		},
+		.synch2 = {
+			.hb = hb,
+			.hf = vm->xres * spml - hb
+		},
+		.syncv = {
+			.vs   = vm->vsync_len,
+			.vdp  = vm->yres,
+			.vbpe = 0,
+			.vbp  = vm->upper_margin,
+			.vfpe = 0,
+			.vfp  = vm->lower_margin
+		},
+		.display = {
+			.dh   = vm->yres - 1,
+			.dw   = vm->xres * spml - 1,
+			.magv = 0,
+			.magh = spml - 1,
+			.dy   = vm->vsync_len + vm->upper_margin - 1,
+			.dx   = (vm->hsync_len + vm->left_margin) * spml - 1 - hadj
+		}
+	};
+}
+
 static struct gs_sync_param vm_to_sp_for_synch_gen(
 	const struct fb_videomode *vm, const struct gs_synch_gen sg)
 {
-	struct gs_sync_param sp = vm_to_sp_sdtv(vm);
+	const bool bc = vm->sync & FB_SYNC_BROADCAST;
+	const bool il = vm->vmode & FB_VMODE_INTERLACED;
+	struct gs_sync_param sp =
+		vm->yres <= 288 &&       bc ? vm_to_sp_sdtv(vm) :
+		vm->yres <= 576 && il && bc ? vm_to_sp_sdtv(vm) :
+					      vm_to_sp_hdtv(vm, sg);
 
 	sp.smode1.gcont = gs_gcont_ycrcb;
 	sp.smode1.sint = 1;