Allow customization of the low DPI clock

amadvance · Feb 17, 2017 · 847462a · 847462a
1 parent 79a9375
commit 847462a
Show file tree

Hide file tree

Showing 2 changed files with 10 additions and 5 deletions.
diff --git a/advance/linux/vfb.c b/advance/linux/vfb.c
@@ -70,6 +70,7 @@ enum fb_wait_enum {
 
 struct fb_option_struct {
 	unsigned hdmi_pclock_low;
+	unsigned dpi_pclock_low;
 };
 
 static struct fb_option_struct fb_option;
@@ -1014,7 +1015,7 @@ static int fb_raspberry_settiming(const adv_crtc* crtc, unsigned* size_x, unsign
 			 * Note that the Horizontal and Vertical clocks remain the same.
 			 */
 			unsigned factor = 0;
-			while (copy.pixelclock <= 31250000 + 50000) {
+			while (copy.pixelclock <= fb_option.dpi_pclock_low + 50000) {
 				++factor;
 				log_std(("video:fb: adjust DPI modeline to increase by factor %u / 4\n", factor));
 				copy.hde += crtc->hde / 4;
@@ -1973,13 +1974,15 @@ void fb_reg(adv_conf* context)
 	assert(!fb_is_active());
 
 	conf_int_register_default(context, "device_hdmi_pclock_low", 0);
+	conf_int_register_default(context, "device_dpi_pclock_low", 31250000);
 }
 
 adv_error fb_load(adv_conf* context)
 {
 	assert(!fb_is_active());
 
 	fb_option.hdmi_pclock_low = conf_int_get_default(context, "device_hdmi_pclock_low");
+	fb_option.dpi_pclock_low = conf_int_get_default(context, "device_dpi_pclock_low");
 
 	return 0;
 }

diff --git a/doc/advdev.d b/doc/advdev.d
@@ -765,20 +765,22 @@ Video Drivers Configuration
 		no - Disable the fast video mode change (default).
 
   fb Configuration Options
-    device_hdmi_pclock_low
+    device_hdmi/dpi_pclock_low
 	Set the minimum pclock frequency used to drive the display. If a lower
 	value is selected, transparently increases the video mode horizontal size
 	until it reaches the allowed pixel clock.
 
 	This option works only with Raspberry Pi, when using the FrameBuffer and
-	the HDMI video interface (and not the DPI interface).
+	the HDMI/DPI video interface.
 
 	The use of this option is discouraged, it's present only for testing.
 
-	device_hdmi_pclock_low PCLOCK
+	:device_hdmi_pclock_low PCLOCK
+	:device_dpi_pclock_low PCLOCK
 
 	Options:
-		PCLOCK - Pixel clock in Hz (default 0).
+		PCLOCK - Pixel clock in Hz (default 0 for HDMI,
+			and 31.25 MHz for DPI).
 
   vbeline Configuration Options
 	The following are the common video configuration options