Re: [PATCH] drm: bridge/dw_hdmi: add audio sample channel status setting

From: Neil Armstrong
Date: Tue Sep 03 2019 - 14:00:43 EST


Hi,

Le 03/09/2019 Ã 11:53, Neil Armstrong a Ãcrit :
> Hi,
>
> On 03/09/2019 07:51, Cheng-Yi Chiang wrote:
>> From: Yakir Yang <ykk@xxxxxxxxxxxxxx>
>>
>> When transmitting IEC60985 linear PCM audio, we configure the
>> Audio Sample Channel Status information of all the channel
>> status bits in the IEC60958 frame.
>> Refer to 60958-3 page 10 for frequency, original frequency, and
>> wordlength setting.
>>
>> This fix the issue that audio does not come out on some monitors
>> (e.g. LG 22CV241)
>>
>> Signed-off-by: Yakir Yang <ykk@xxxxxxxxxxxxxx>
>> Signed-off-by: Cheng-Yi Chiang <cychiang@xxxxxxxxxxxx>
>> ---
>> drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 59 +++++++++++++++++++++++
>> drivers/gpu/drm/bridge/synopsys/dw-hdmi.h | 20 ++++++++
>> 2 files changed, 79 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
>> index bd65d0479683..34d46e25d610 100644
>> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
>> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
>> @@ -582,6 +582,63 @@ static unsigned int hdmi_compute_n(unsigned int freq, unsigned long pixel_clk)
>> return n;
>> }
>>
>> +static void hdmi_set_schnl(struct dw_hdmi *hdmi)
>> +{
>> + u8 aud_schnl_samplerate;
>> + u8 aud_schnl_8;
>> +
>> + /* These registers are on RK3288 using version 2.0a. */
>> + if (hdmi->version != 0x200a)
>> + return;
>
> Are these limited to the 2.0a version *in* RK3288, or 2.0a version on all
> SoCs ?

After investigations, Amlogic sets these registers on their 2.0a version
aswell, and Jernej (added in Cc) reported me Allwinner sets them on their
< 2.0a and > 2.0a IPs versions.

Can you check on the Rockchip IP versions in RK3399 ?

For reference, the HDMI 1.4a IP version allwinner setups is:
https://github.com/Allwinner-Homlet/H3-BSP4.4-linux/blob/master/drivers/video/fbdev/sunxi/disp2/hdmi/hdmi_bsp_sun8iw7.c#L531-L539
(registers a "scrambled" but a custom bit can reset to the original mapping,
0x1066 ... 0x106f)

Neil

>
>> +
>> + switch (hdmi->sample_rate) {
>> + case 32000:
>> + aud_schnl_samplerate = HDMI_FC_AUDSCHNLS7_SMPRATE_32K;
>> + break;
>> + case 44100:
>> + aud_schnl_samplerate = HDMI_FC_AUDSCHNLS7_SMPRATE_44K1;
>> + break;
>> + case 48000:
>> + aud_schnl_samplerate = HDMI_FC_AUDSCHNLS7_SMPRATE_48K;
>> + break;
>> + case 88200:
>> + aud_schnl_samplerate = HDMI_FC_AUDSCHNLS7_SMPRATE_88K2;
>> + break;
>> + case 96000:
>> + aud_schnl_samplerate = HDMI_FC_AUDSCHNLS7_SMPRATE_96K;
>> + break;
>> + case 176400:
>> + aud_schnl_samplerate = HDMI_FC_AUDSCHNLS7_SMPRATE_176K4;
>> + break;
>> + case 192000:
>> + aud_schnl_samplerate = HDMI_FC_AUDSCHNLS7_SMPRATE_192K;
>> + break;
>> + case 768000:
>> + aud_schnl_samplerate = HDMI_FC_AUDSCHNLS7_SMPRATE_768K;
>> + break;
>> + default:
>> + dev_warn(hdmi->dev, "Unsupported audio sample rate (%u)\n",
>> + hdmi->sample_rate);
>> + return;
>> + }
>> +
>> + /* set channel status register */
>> + hdmi_modb(hdmi, aud_schnl_samplerate, HDMI_FC_AUDSCHNLS7_SMPRATE_MASK,
>> + HDMI_FC_AUDSCHNLS7);
>> +
>> + /*
>> + * Set original frequency to be the same as frequency.
>> + * Use one-complement value as stated in IEC60958-3 page 13.
>> + */
>> + aud_schnl_8 = (~aud_schnl_samplerate) <<
>> + HDMI_FC_AUDSCHNLS8_ORIGSAMPFREQ_OFFSET;
>> +
>> + /* This means word length is 16 bit. Refer to IEC60958-3 page 12. */
>> + aud_schnl_8 |= 2 << HDMI_FC_AUDSCHNLS8_WORDLEGNTH_OFFSET;
>> +
>> + hdmi_writeb(hdmi, aud_schnl_8, HDMI_FC_AUDSCHNLS8);
>> +}
>> +
>> static void hdmi_set_clk_regenerator(struct dw_hdmi *hdmi,
>> unsigned long pixel_clk, unsigned int sample_rate)
>> {
>> @@ -620,6 +677,8 @@ static void hdmi_set_clk_regenerator(struct dw_hdmi *hdmi,
>> hdmi->audio_cts = cts;
>> hdmi_set_cts_n(hdmi, cts, hdmi->audio_enable ? n : 0);
>> spin_unlock_irq(&hdmi->audio_lock);
>> +
>> + hdmi_set_schnl(hdmi);
>> }
>>
>> static void hdmi_init_clk_regenerator(struct dw_hdmi *hdmi)
>> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.h b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.h
>> index 6988f12d89d9..619ebc1c8354 100644
>> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.h
>> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.h
>> @@ -158,6 +158,17 @@
>> #define HDMI_FC_SPDDEVICEINF 0x1062
>> #define HDMI_FC_AUDSCONF 0x1063
>> #define HDMI_FC_AUDSSTAT 0x1064
>> +#define HDMI_FC_AUDSV 0x1065
>> +#define HDMI_FC_AUDSU 0x1066
>> +#define HDMI_FC_AUDSCHNLS0 0x1067
>> +#define HDMI_FC_AUDSCHNLS1 0x1068
>> +#define HDMI_FC_AUDSCHNLS2 0x1069
>> +#define HDMI_FC_AUDSCHNLS3 0x106a
>> +#define HDMI_FC_AUDSCHNLS4 0x106b
>> +#define HDMI_FC_AUDSCHNLS5 0x106c
>> +#define HDMI_FC_AUDSCHNLS6 0x106d
>> +#define HDMI_FC_AUDSCHNLS7 0x106e
>> +#define HDMI_FC_AUDSCHNLS8 0x106f
>> #define HDMI_FC_DATACH0FILL 0x1070
>> #define HDMI_FC_DATACH1FILL 0x1071
>> #define HDMI_FC_DATACH2FILL 0x1072
>> @@ -706,6 +717,15 @@ enum {
>> /* HDMI_FC_AUDSCHNLS7 field values */
>> HDMI_FC_AUDSCHNLS7_ACCURACY_OFFSET = 4,
>> HDMI_FC_AUDSCHNLS7_ACCURACY_MASK = 0x30,
>> + HDMI_FC_AUDSCHNLS7_SMPRATE_MASK = 0x0f,
>> + HDMI_FC_AUDSCHNLS7_SMPRATE_192K = 0xe,
>> + HDMI_FC_AUDSCHNLS7_SMPRATE_176K4 = 0xc,
>> + HDMI_FC_AUDSCHNLS7_SMPRATE_96K = 0xa,
>> + HDMI_FC_AUDSCHNLS7_SMPRATE_768K = 0x9,
>> + HDMI_FC_AUDSCHNLS7_SMPRATE_88K2 = 0x8,
>> + HDMI_FC_AUDSCHNLS7_SMPRATE_32K = 0x3,
>> + HDMI_FC_AUDSCHNLS7_SMPRATE_48K = 0x2,
>> + HDMI_FC_AUDSCHNLS7_SMPRATE_44K1 = 0x0,
>>
>> /* HDMI_FC_AUDSCHNLS8 field values */
>> HDMI_FC_AUDSCHNLS8_ORIGSAMPFREQ_MASK = 0xf0,
>>
>