Hello, As there is no more feedback on this patch, should i suppose that I need to abandon it? I can integrate it in my driver... but as, N and CTS calculation is not platform dependent, this would make sense to add it in a generic part. (Example of another platform that could use it: https://patchwork.kernel.org/patch/8887341) Thanks and regards Arnaud On 04/28/2016 02:13 PM, Arnaud Pouliquen wrote: > Add linux-fbdev diffusion list in loop for patch-set review. > > On 04/21/2016 05:29 PM, Arnaud POULIQUEN wrote: >> Add helper functions to compute HDMI CTS and N parameters. >> Implementation is based on HDMI 1.4b specification. >> >> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@xxxxxx> >> Acked-by: Benjamin Gaignard <benjamin.gaignard@xxxxxxxxxx> >> Acked-by: Vincent ABRIOU <vincent.abriou@xxxxxx> >> --- >> drivers/video/hdmi.c | 208 +++++++++++++++++++++++++++++++++++++++++++++++++++ >> include/linux/hdmi.h | 24 ++++++ >> 2 files changed, 232 insertions(+) >> >> diff --git a/drivers/video/hdmi.c b/drivers/video/hdmi.c >> index 1626892..5d124ef 100644 >> --- a/drivers/video/hdmi.c >> +++ b/drivers/video/hdmi.c >> @@ -1242,3 +1242,211 @@ 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 hdmi_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][13] = { >> + [HDMI_AUDIO_N_CTS_32KHZ] = { >> + /* N and CTS values for 32 kHz rate*/ >> + { 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 (truncated)*/ >> + { 296703297, { 5824, 421875, 0 } }, /* 297/1.001 MHz (rounded)*/ >> + { 297000000, { 3072, 222750, 0 } }, /* 297 MHz */ >> + }, >> + [HDMI_AUDIO_N_CTS_44_1KHZ] = { >> + /* N and CTS values for 44.1 kHz, 88.2 kHz and 176.4 kHz rates*/ >> + { 25174825, { 7007, 31250, 0 } }, /* 25.20/1.001 MHz */ >> + { 25200000, { 6272, 28000, 0 } }, /* 25.20 MHz */ >> + { 27000000, { 6272, 30000, 0 } }, /* 27.00 MHz */ >> + { 27027000, { 6272, 30030, 0 } }, /* 27.00*1.001 MHz */ >> + { 54000000, { 6272, 60000, 0 } }, /* 54.00 MHz */ >> + { 54054000, { 6272, 60060, 0 } }, /* 54.00*1.001 MHz */ >> + { 74175824, { 17836, 234375, 0 } }, /* 74.25/1.001 MHz */ >> + { 74250000, { 6272, 82500, 0 } }, /* 74.25 MHz */ >> + { 148351648, { 8918, 234375, 0 } }, /* 148.50/1.001 MHz */ >> + { 148500000, { 6272, 165000, 0 } }, /* 148.50 MHz */ >> + { 296703296, { 4459, 234375, 0 } }, /* 297/1.001 MHz (truncated) */ >> + { 296703297, { 4459, 234375, 0 } }, /* 297/1.001 MHz (rounded) */ >> + { 297000000, { 4704, 247500, 0 } }, /* 297 MHz */ >> + }, >> + [HDMI_AUDIO_N_CTS_48KHZ] = { >> + /* N and CTS values for 48 kHz, 96 kHz and 192 kHz rates*/ >> + { 25174825, { 6864, 28125, 0 } }, /* 25.20/1.001 MHz */ >> + { 25200000, { 6144, 25200, 0 } }, /* 25.20 MHz */ >> + { 27000000, { 6144, 27000, 0 } }, /* 27.00 MHz */ >> + { 27027000, { 6144, 27027, 0 } }, /* 27.00*1.001 MHz */ >> + { 54000000, { 6144, 54000, 0 } }, /* 54.00 MHz */ >> + { 54054000, { 6144, 54054, 0 } }, /* 54.00*1.001 MHz */ >> + { 74175824, { 11648, 140625, 0 } }, /* 74.25/1.001 MHz */ >> + { 74250000, { 6144, 74250, 0 } }, /* 74.25 MHz */ >> + { 148351648, { 5824, 140625, 0 } }, /* 148.50/1.001 MHz */ >> + { 148500000, { 6144, 148500, 0 } }, /* 148.50 MHz */ >> + { 296703296, { 5824, 281250, 0 } }, /* 297/1.001 MHz (truncated) */ >> + { 296703297, { 5824, 281250, 0 } }, /* 297/1.001 MHz (rounded) */ >> + { 297000000, { 5120, 247500, 0 } }, /* 297 MHz */ >> + } >> +}; >> + >> +/** >> + * hdmi_audio_get_coherent_n_cts() - compute N and CTS parameters for coherent >> + * clocks. Coherent clock means that audio and TMDS clocks have the same >> + * source (no drifts between clocks). >> + * >> + * @audio_fs: audio frame clock frequency in Hz >> + * @tmds_clk: HDMI TMDS clock frequency in Hz >> + * @n_cts: N and CTS parameter returned to user >> + * >> + * Values computed are based on table described in HDMI specification 1.4b >> + * >> + * Returns 0 on success or a negative error code on failure. >> + */ >> +int hdmi_audio_get_coherent_n_cts(unsigned int audio_fs, >> + unsigned int tmds_clk, >> + struct hdmi_audio_n_cts *n_cts) >> +{ >> + int audio_freq_id, i; >> + int rate_coeff = 1; >> + u64 val, min; >> + const struct hdmi_audio_acr *acr_table; >> + const struct hdmi_audio_n_cts *predef_n_cts = NULL; >> + >> + switch (audio_fs) { >> + case 32000: >> + audio_freq_id = HDMI_AUDIO_N_CTS_32KHZ; >> + n_cts->n = 4096; >> + break; >> + case 44100: >> + audio_freq_id = HDMI_AUDIO_N_CTS_44_1KHZ; >> + n_cts->n = 6272; >> + break; >> + case 48000: >> + audio_freq_id = HDMI_AUDIO_N_CTS_48KHZ; >> + n_cts->n = 6144; >> + break; >> + case 88200: >> + audio_freq_id = HDMI_AUDIO_N_CTS_44_1KHZ; >> + rate_coeff = 2; >> + n_cts->n = 6272 * 2; >> + break; >> + case 96000: >> + audio_freq_id = HDMI_AUDIO_N_CTS_48KHZ; >> + rate_coeff = 2; >> + n_cts->n = 6144 * 2; >> + break; >> + case 176400: >> + audio_freq_id = HDMI_AUDIO_N_CTS_44_1KHZ; >> + rate_coeff = 4; >> + n_cts->n = 6272 * 4; >> + break; >> + case 192000: >> + audio_freq_id = HDMI_AUDIO_N_CTS_48KHZ; >> + rate_coeff = 4; >> + n_cts->n = 6144 * 4; >> + break; >> + default: >> + return -EINVAL; >> + } >> + >> + acr_table = hdmi_audio_standard_acr[audio_freq_id]; >> + for (i = 0; i < ARRAY_SIZE(hdmi_audio_standard_acr[0]); i++) { >> + if (tmds_clk == acr_table[i].tmds_clk) { >> + predef_n_cts = &acr_table[i].n_cts; >> + n_cts->n = predef_n_cts->n * rate_coeff; >> + n_cts->cts = predef_n_cts->cts; >> + n_cts->cts_1_ratio = predef_n_cts->cts_1_ratio; >> + return 0; >> + } >> + } >> + >> + /* >> + * Pre-defined frequency not found. Compute CTS using formula: >> + * CTS = (Ftdms_clk * N) / (128 * audio_fs) >> + */ >> + val = (u64)tmds_clk * n_cts->n; >> + n_cts->cts = div64_u64(val, 128UL * audio_fs); >> + >> + n_cts->cts_1_ratio = 0; >> + min = (u64)n_cts->cts * 128UL * audio_fs; >> + if (min < val) { >> + /* >> + * Non-accurate value for CTS >> + * compute ratio, needed by user to alternate in ACR >> + * between CTS and CTS + 1 value. >> + */ >> + n_cts->cts_1_ratio = ((u32)(val - min)) * 100 / >> + (128 * audio_fs); >> + } >> + >> + return 0; >> +} >> +EXPORT_SYMBOL(hdmi_audio_get_coherent_n_cts); >> + >> +/** >> + * hdmi_audio_get_non_coherent_n() - get N parameter for non-coherent >> + * clocks. None-coherent clocks means that audio and TMDS clocks have not the >> + * same source (drifts between clocks). In this case assumption is that CTS is >> + * automatically calculated by hardware. >> + * >> + * @audio_fs: audio frame clock frequency in Hz >> + * >> + * Values computed are based on table described in HDMI specification 1.4b >> + * >> + * Returns n value. >> + */ >> +int hdmi_audio_get_non_coherent_n(unsigned int audio_fs) >> +{ >> + unsigned int n; >> + >> + switch (audio_fs) { >> + case 32000: >> + n = 4096; >> + break; >> + case 44100: >> + n = 6272; >> + break; >> + case 48000: >> + n = 6144; >> + break; >> + case 88200: >> + n = 6272 * 2; >> + break; >> + case 96000: >> + n = 6144 * 2; >> + break; >> + case 176400: >> + n = 6272 * 4; >> + break; >> + case 192000: >> + n = 6144 * 4; >> + break; >> + default: >> + /* Not pre-defined, recommended value: 128 * fs / 1000 */ >> + n = (audio_fs * 128) / 1000; >> + } >> + >> + return n; >> +} >> +EXPORT_SYMBOL(hdmi_audio_get_non_coherent_n); >> + >> diff --git a/include/linux/hdmi.h b/include/linux/hdmi.h >> index e974420..088d09f8 100644 >> --- a/include/linux/hdmi.h >> +++ b/include/linux/hdmi.h >> @@ -333,4 +333,28 @@ int hdmi_infoframe_unpack(union hdmi_infoframe *frame, void *buffer); >> void hdmi_infoframe_log(const char *level, struct device *dev, >> union hdmi_infoframe *frame); >> >> +/** >> + * struct hdmi_audio_n_cts - n and cts parameter for ACR packets >> + * @n: N parameter >> + * @cts: CTS parameter >> + * @cts_1_ratio: ratio from 0 to 99 to alternate "CTS" and "CTS + 1" values >> + * ratio = 0: CTS parameter is accurate, no need to alternate with "CTS + 1" >> + * value >> + * ratio = x: Need to alternate with ACR "CTS + 1" value x percent of the time >> + * to generate accurate audio clock >> + * as exemple: if cts_1_ratio = 30: to have an accurate value, user >> + * should transfer CTS value 70% of the time and (CTS+1) value 30% of the time >> + */ >> +struct hdmi_audio_n_cts { >> + unsigned int n; >> + unsigned int cts; >> + unsigned int cts_1_ratio; >> +}; >> + >> +int hdmi_audio_get_coherent_n_cts(unsigned int audio_fs, >> + unsigned int tmds_clk, >> + struct hdmi_audio_n_cts *n_cts); >> + >> +int hdmi_audio_get_non_coherent_n(unsigned int audio_fs); >> + >> #endif /* _DRM_HDMI_H */ >> _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
