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

[Cheng-yi Chiang <cychiang@chromium.org>]

On Wed, Sep 4, 2019 at 2:08 AM Jernej Škrabec <jernej.skrabec@siol.net> wrote:
>
> Hi!
>
> Dne torek, 03. september 2019 ob 20:00:33 CEST je Neil Armstrong napisal(a):
> > Hi,
> >
> > Le 03/09/2019 à 11:53, Neil Armstrong a écrit :
> > > Hi,
> > >
> > > On 03/09/2019 07:51, Cheng-Yi Chiang wrote:
> > >> From: Yakir Yang <ykk@rock-chips.com>
> > >>
> > >> 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@rock-chips.com>
> > >> Signed-off-by: Cheng-Yi Chiang <cychiang@chromium.org>
> > >> ---
> > >>
> > >>  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/vide
> > o/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)
>
> For easier reading, here is similar, but annotated version: http://ix.io/1Ub6
> Check function bsp_hdmi_audio().
>
> Unless there is a special reason, you can just remove that check.
>

Thanks for the great reference.
I also see that I need to set the word length according to the desired
value passed by dw_hdmi_i2s_hw_params in dw-hdmi-i2s-audio.c.
Will fix in v2.

> Best regards,
> Jernej
>
> >
> > 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,
>
>
>
>