Hi Arnaud,
Am Freitag, den 22.01.2016, 18:48 +0100 schrieb Arnaud Pouliquen:
From: Moise Gergaud moise.gergaud@st.com
Add helper function to compute HDMI CTS and N parameters. Implementation is based on HDMI 1.4b specification.
Signed-off-by: Arnaud Pouliquen arnaud.pouliquen@st.com
Reviewed-by: Philipp Zabel p.zabel@pengutronix.de Tested-by: Philipp Zabel p.zabel@pengutronix.de
drivers/video/hdmi.c | 222 +++++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/hdmi.h | 22 +++++ 2 files changed, 244 insertions(+)
diff --git a/drivers/video/hdmi.c b/drivers/video/hdmi.c index 1626892..be8b8ed 100644 --- a/drivers/video/hdmi.c +++ b/drivers/video/hdmi.c @@ -1242,3 +1242,225 @@ int hdmi_infoframe_unpack(union hdmi_infoframe *frame, void *buffer) return ret; } EXPORT_SYMBOL(hdmi_infoframe_unpack);
+/**
- audio clock regeneration (acr) parameters
- N and CTS computation are based on HDMI specification 1.4b
- */
+enum audio_rate {
- HDMI_AUDIO_N_CTS_32KHZ,
- HDMI_AUDIO_N_CTS_44_1KHZ,
- HDMI_AUDIO_N_CTS_48KHZ,
+};
+struct hdmi_audio_acr {
- unsigned int tmds_clk;
- struct hdmi_audio_n_cts n_cts;
+};
+static const struct hdmi_audio_acr hdmi_audio_standard_acr[3][12] = {
- { /*32 kHz*/
{ 25174825, { 4576, 28125, 0 } }, /* 25,20/1.001 MHz */{ 25200000, { 4096, 25200, 0 } }, /* 25.20 MHz */{ 27000000, { 4096, 27000, 0 } }, /* 27.00 MHz */{ 27027000, { 4096, 27027, 0 } }, /* 27.00*1.001 MHz */{ 54000000, { 4096, 54000, 0 } }, /* 54.00 MHz */{ 54054000, { 4096, 54054, 0 } }, /* 54.00*1.001 MHz */{ 74175824, { 11648, 210937, 50 } }, /* 74.25/1.001 MHz */{ 74250000, { 4096, 74250, 0 } }, /* 74.25 MHz */{ 148351648, { 11648, 421875, 0 } }, /* 148.50/1.001 MHz */{ 148500000, { 4096, 148500, 0 } }, /* 148.50 MHz */{ 296703296, { 5824, 421875, 0 } }, /* 297/1.001 MHz */
297/1.001 is about 296703296.7. Should this be rounded to 296703297 ?
regards Philipp