Module Name: src
Committed By: jmcneill
Date: Mon Nov 4 09:38:39 UTC 2019
Modified Files:
src/sys/arch/arm/ti: ti_lcdc.c
Log Message:
Select closest rate to desired pixel clock
To generate a diff of this commit:
cvs rdiff -u -r1.2 -r1.3 src/sys/arch/arm/ti/ti_lcdc.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/arch/arm/ti/ti_lcdc.c
diff -u src/sys/arch/arm/ti/ti_lcdc.c:1.2 src/sys/arch/arm/ti/ti_lcdc.c:1.3
--- src/sys/arch/arm/ti/ti_lcdc.c:1.2 Sun Nov 3 23:31:49 2019
+++ src/sys/arch/arm/ti/ti_lcdc.c Mon Nov 4 09:38:38 2019
@@ -1,4 +1,4 @@
-/* $NetBSD: ti_lcdc.c,v 1.2 2019/11/03 23:31:49 jmcneill Exp $ */
+/* $NetBSD: ti_lcdc.c,v 1.3 2019/11/04 09:38:38 jmcneill Exp $ */
/*-
* Copyright (c) 2019 Jared D. McNeill <jmcne...@invisible.ca>
@@ -27,7 +27,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: ti_lcdc.c,v 1.2 2019/11/03 23:31:49 jmcneill Exp $");
+__KERNEL_RCSID(0, "$NetBSD: ti_lcdc.c,v 1.3 2019/11/04 09:38:38 jmcneill Exp $");
#include <sys/param.h>
#include <sys/bus.h>
@@ -159,8 +159,8 @@ tilcdc_mode_set(struct drm_crtc *crtc, s
{
struct tilcdc_crtc *mixer_crtc = to_tilcdc_crtc(crtc);
struct tilcdc_softc * const sc = mixer_crtc->sc;
+ int clk_div, div, diff, best_diff;
uint32_t val;
- u_int clk_div;
const u_int hspw = adjusted_mode->crtc_hsync_end - adjusted_mode->crtc_hsync_start;
const u_int hbp = adjusted_mode->crtc_htotal - adjusted_mode->crtc_hsync_end;
@@ -170,9 +170,16 @@ tilcdc_mode_set(struct drm_crtc *crtc, s
const u_int vfp = adjusted_mode->crtc_vsync_start - adjusted_mode->crtc_vdisplay;
const u_int rate = clk_get_rate(sc->sc_clk);
- for (clk_div = 2; clk_div < 255; clk_div++) {
- if (rate / clk_div <= (int)adjusted_mode->crtc_clock * 1000)
- break;
+
+ clk_div = 255;
+ best_diff = -1;
+ for (div = 2; div < 255; div++) {
+ const int pixel_clock = (rate / div) / 1000;
+ diff = abs(adjusted_mode->crtc_clock - pixel_clock);
+ if (best_diff == -1 || diff < best_diff) {
+ best_diff = diff;
+ clk_div = div;
+ }
}
if (clk_div == 255) {
device_printf(sc->sc_dev, "couldn't configure pixel clock (%u)\n",
