[PATCH 04/12] drm: Add support for alternate clocks of 4k modes

Damien Lespiau
2013-08-13T23:17:20Z

Suggested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
---
drivers/gpu/drm/drm_edid.c | 68 ++++++++++++++++++++++++++++++++++++++++++----
1 file changed, 62 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 0faa08e..606335f 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -2409,6 +2409,54 @@ u8 drm_match_cea_mode(const struct drm_display_mode *to_match)
}
EXPORT_SYMBOL(drm_match_cea_mode);

+/*
+ * Calculate the alternate clock for HDMI modes (those from the HDMI vendor
+ * specific block).
+ *
+ * It's almost like cea_mode_alternate_clock(), we just need to add an
+ * exception for the VIC 4 mode (4096x2160@24Hz): no alternate clock for this
+ * one.
+ */
+static unsigned int
+hdmi_mode_alternate_clock(const struct drm_display_mode *hdmi_mode)
+{
+ if (hdmi_mode->vdisplay == 4096 && hdmi_mode->hdisplay == 2160)
+ return hdmi_mode->clock;
+
+ return cea_mode_alternate_clock(hdmi_mode);
+}
+
+/*
+ * drm_match_cea_mode - look for a HDMI mode matching given mode
+ * @to_match: display mode
+ *
+ * An HDMI mode is one defined in the HDMI vendor specific block.
+ *
+ * Returns the HDMI Video ID (VIC) of the mode or 0 if it isn't one.
+ */
+static u8 drm_match_hmdi_mode(const struct drm_display_mode *to_match)
+{
+ u8 mode;
+
+ if (!to_match->clock)
+ return 0;
+
+ for (mode = 0; mode < ARRAY_SIZE(edid_4k_modes); mode++) {
+ const struct drm_display_mode *hdmi_mode = &edid_4k_modes[mode];
+ unsigned int clock1, clock2;
+
+ /* Make sure to also match alternate clocks */
+ clock1 = hdmi_mode->clock;
+ clock2 = hdmi_mode_alternate_clock(hdmi_mode);
+
+ if ((KHZ2PICOS(to_match->clock) == KHZ2PICOS(clock1) ||
+ KHZ2PICOS(to_match->clock) == KHZ2PICOS(clock2)) &&
+ drm_mode_equal_no_clocks(to_match, hdmi_mode))
+ return mode + 1;
+ }
+ return 0;
+}
+
static int
add_alternate_cea_modes(struct drm_connector *connector, struct edid *edid)
{
@@ -2426,18 +2474,26 @@ add_alternate_cea_modes(struct drm_connector *connector, struct edid *edid)
* with the alternate clock for certain CEA modes.
*/
list_for_each_entry(mode, &connector->probed_modes, head) {
- const struct drm_display_mode *cea_mode;
+ const struct drm_display_mode *cea_mode = NULL;
struct drm_display_mode *newmode;
- u8 cea_mode_idx = drm_match_cea_mode(mode) - 1;
+ u8 mode_idx = drm_match_cea_mode(mode) - 1;
unsigned int clock1, clock2;

- if (cea_mode_idx >= ARRAY_SIZE(edid_cea_modes))
- continue;
+ if (mode_idx < ARRAY_SIZE(edid_cea_modes)) {
+ cea_mode = &edid_cea_modes[mode_idx];
+ clock2 = cea_mode_alternate_clock(cea_mode);
+ } else {
+ mode_idx = drm_match_hmdi_mode(mode) - 1;
+ if (mode_idx < ARRAY_SIZE(edid_4k_modes)) {
+ cea_mode = &edid_4k_modes[mode_idx];
+ clock2 = hdmi_mode_alternate_clock(cea_mode);
+ }
+ }

- cea_mode = &edid_cea_modes[cea_mode_idx];
+ if (!cea_mode)
+ continue;

clock1 = cea_mode->clock;
- clock2 = cea_mode_alternate_clock(cea_mode);

if (clock1 == clock2)
continue;
--
1.8.3.1

_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org