Hello Philipp,
FYI, i'm currently finalizing a new version of the helper function with minor updates ( typo and code optimization), i should send it tomorrow.
Regards Arnaud
On 04/20/2016 11:00 AM, Philipp Zabel wrote:
Use the hdmi helper function [1] to calculate N and CTS.
[1] https://patchwork.kernel.org/patch/8091531/ ("video: hdmi: add helper function for N and CTS")
Signed-off-by: Philipp Zabel p.zabel@pengutronix.de
drivers/gpu/drm/mediatek/mtk_hdmi.c | 85 +++++++++---------------------------- 1 file changed, 21 insertions(+), 64 deletions(-)
diff --git a/drivers/gpu/drm/mediatek/mtk_hdmi.c b/drivers/gpu/drm/mediatek/mtk_hdmi.c index 06e3811..da6edef 100644 --- a/drivers/gpu/drm/mediatek/mtk_hdmi.c +++ b/drivers/gpu/drm/mediatek/mtk_hdmi.c @@ -656,65 +656,6 @@ static const struct hdmi_acr_n hdmi_rec_n_table[] = { { 0, { 4096, 6272, 6144 } }, /* all other TMDS clocks */ };
-/**
- hdmi_recommended_n() - Return N value recommended by HDMI specification
- @freq: audio sample rate in Hz
- @clock: rounded TMDS clock in kHz
- */
-static unsigned int hdmi_recommended_n(unsigned int freq, unsigned int clock) -{
- const struct hdmi_acr_n *recommended;
- unsigned int i;
- for (i = 0; i < ARRAY_SIZE(hdmi_rec_n_table) - 1; i++) {
if (clock == hdmi_rec_n_table[i].clock)break;- }
- recommended = hdmi_rec_n_table + i;
- switch (freq) {
- case 32000:
return recommended->n[0];- case 44100:
return recommended->n[1];- case 48000:
return recommended->n[2];- case 88200:
return recommended->n[1] * 2;- case 96000:
return recommended->n[2] * 2;- case 176400:
return recommended->n[1] * 4;- case 192000:
return recommended->n[2] * 4;- default:
return (128 * freq) / 1000;- }
-}
-static unsigned int hdmi_mode_clock_to_hz(unsigned int clock) -{
- switch (clock) {
- case 25175:
return 25174825; /* 25.2/1.001 MHz */- case 74176:
return 74175824; /* 74.25/1.001 MHz */- case 148352:
return 148351648; /* 148.5/1.001 MHz */- case 296703:
return 296703297; /* 297/1.001 MHz */- default:
return clock * 1000;- }
-}
-static unsigned int hdmi_expected_cts(unsigned int audio_sample_rate,
unsigned int tmds_clock, unsigned int n)-{
- return DIV_ROUND_CLOSEST_ULL((u64)hdmi_mode_clock_to_hz(tmds_clock) * n,
128 * audio_sample_rate);-}
static void do_hdmi_hw_aud_set_ncts(struct mtk_hdmi *hdmi, unsigned int n, unsigned int cts) { @@ -739,21 +680,37 @@ static void do_hdmi_hw_aud_set_ncts(struct mtk_hdmi *hdmi, unsigned int n, mtk_hdmi_write(hdmi, GRL_NCTS, val[i]); }
+static unsigned int hdmi_mode_clock_to_hz(unsigned int clock) +{
- switch (clock) {
- case 25175:
return 25174825; /* 25.2/1.001 MHz */- case 74176:
return 74175824; /* 74.25/1.001 MHz */- case 148352:
return 148351648; /* 148.5/1.001 MHz */- case 296703:
return 296703296; /* 297/1.001 MHz */- default:
return clock * 1000;- }
+}
static void mtk_hdmi_hw_aud_set_ncts(struct mtk_hdmi *hdmi, unsigned int sample_rate, unsigned int clock) {
- unsigned int n, cts;
- struct hdmi_audio_n_cts n_cts;
- n = hdmi_recommended_n(sample_rate, clock);
- cts = hdmi_expected_cts(sample_rate, clock, n);
hdmi_audio_get_coherent_n_cts(sample_rate, hdmi_mode_clock_to_hz(clock),
&n_cts);dev_dbg(hdmi->dev, "%s: sample_rate=%u, clock=%d, cts=%u, n=%u\n",
__func__, sample_rate, clock, n, cts);
__func__, sample_rate, clock, n_cts.cts, n_cts.n);mtk_hdmi_mask(hdmi, DUMMY_304, AUDIO_I2S_NCTS_SEL_64, AUDIO_I2S_NCTS_SEL);
- do_hdmi_hw_aud_set_ncts(hdmi, n, cts);
- do_hdmi_hw_aud_set_ncts(hdmi, n_cts.n, n_cts.cts);
}
static u8 mtk_hdmi_aud_get_chnl_count(enum hdmi_aud_channel_type channel_type)