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@xxxxxxxxxxxxxx> > --- > 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) > _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
