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authorRicardo Neri <ricardo.neri@ti.com>2012-03-23 22:49:02 +0100
committerTomi Valkeinen <tomi.valkeinen@ti.com>2012-05-11 14:17:08 +0200
commit25a653597ee63119a477e9bdeb6b41bd7cd56140 (patch)
treedef05373310514afb1ce680ed741c52c54baf134 /drivers
parentOMAPDSS: HDMI: Relocate N/CTS calculation (diff)
downloadlinux-25a653597ee63119a477e9bdeb6b41bd7cd56140.tar.xz
linux-25a653597ee63119a477e9bdeb6b41bd7cd56140.zip
OMAPDSS: HDMI: Add support for more audio sample rates in N/CTS calculation
Add support for more sample rates when calculating N and CTS. This covers all the audio sample rates that an HDMI source is allowed to transmit according to the HDMI 1.4a specification. Also, reorganize the logic for the calculation when using deep color. Signed-off-by: Ricardo Neri <ricardo.neri@ti.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/video/omap2/dss/hdmi.c88
1 files changed, 74 insertions, 14 deletions
diff --git a/drivers/video/omap2/dss/hdmi.c b/drivers/video/omap2/dss/hdmi.c
index 0cdb11976091..09fdbf8714ea 100644
--- a/drivers/video/omap2/dss/hdmi.c
+++ b/drivers/video/omap2/dss/hdmi.c
@@ -558,6 +558,7 @@ static void hdmi_put_clocks(void)
int hdmi_compute_acr(u32 sample_freq, u32 *n, u32 *cts)
{
u32 deep_color;
+ bool deep_color_correct = false;
u32 pclk = hdmi.ip_data.cfg.timings.pixel_clock;
if (n == NULL || cts == NULL)
@@ -566,29 +567,88 @@ int hdmi_compute_acr(u32 sample_freq, u32 *n, u32 *cts)
/* TODO: When implemented, query deep color mode here. */
deep_color = 100;
+ /*
+ * When using deep color, the default N value (as in the HDMI
+ * specification) yields to an non-integer CTS. Hence, we
+ * modify it while keeping the restrictions described in
+ * section 7.2.1 of the HDMI 1.4a specification.
+ */
switch (sample_freq) {
case 32000:
- if ((deep_color == 125) && ((pclk == 54054) ||
- (pclk == 74250)))
- *n = 8192;
- else
- *n = 4096;
+ case 48000:
+ case 96000:
+ case 192000:
+ if (deep_color == 125)
+ if (pclk == 27027 || pclk == 74250)
+ deep_color_correct = true;
+ if (deep_color == 150)
+ if (pclk == 27027)
+ deep_color_correct = true;
break;
case 44100:
- *n = 6272;
- break;
- case 48000:
- if ((deep_color == 125) && ((pclk == 54054) ||
- (pclk == 74250)))
- *n = 8192;
- else
- *n = 6144;
+ case 88200:
+ case 176400:
+ if (deep_color == 125)
+ if (pclk == 27027)
+ deep_color_correct = true;
break;
default:
- *n = 0;
return -EINVAL;
}
+ if (deep_color_correct) {
+ switch (sample_freq) {
+ case 32000:
+ *n = 8192;
+ break;
+ case 44100:
+ *n = 12544;
+ break;
+ case 48000:
+ *n = 8192;
+ break;
+ case 88200:
+ *n = 25088;
+ break;
+ case 96000:
+ *n = 16384;
+ break;
+ case 176400:
+ *n = 50176;
+ break;
+ case 192000:
+ *n = 32768;
+ break;
+ default:
+ return -EINVAL;
+ }
+ } else {
+ switch (sample_freq) {
+ case 32000:
+ *n = 4096;
+ break;
+ case 44100:
+ *n = 6272;
+ break;
+ case 48000:
+ *n = 6144;
+ break;
+ case 88200:
+ *n = 12544;
+ break;
+ case 96000:
+ *n = 12288;
+ break;
+ case 176400:
+ *n = 25088;
+ break;
+ case 192000:
+ *n = 24576;
+ break;
+ default:
+ return -EINVAL;
+ }
+ }
/* Calculate CTS. See HDMI 1.3a or 1.4a specifications */
*cts = pclk * (*n / 128) * deep_color / (sample_freq / 10);