[PATCH v1 3/6] ALSA: hda/tegra: Update scratch reg. communication

From: Mohan Kumar
Date: Wed Feb 09 2022 - 00:16:49 EST


Tegra234 chip scratch register communication between audio
and hdmi driver differs slightly in the way it triggers the
interrupt compared to legacy chips. Interrupt is triggered
by writing non-zero values to verb 0xF80 instead of 31st bit
of scratch register.

DP MST support changed the NID to be used for scratch register
read/write from audio function group NID to Converter widget NID.

Signed-off-by: Mohan Kumar <mkumard@xxxxxxxxxx>
---
include/sound/hda_codec.h | 4 +++
sound/pci/hda/patch_hdmi.c | 61 ++++++++++++++++++++++++++++----------
2 files changed, 49 insertions(+), 16 deletions(-)

diff --git a/include/sound/hda_codec.h b/include/sound/hda_codec.h
index 82d9daa17851..c1c19dd4c423 100644
--- a/include/sound/hda_codec.h
+++ b/include/sound/hda_codec.h
@@ -240,6 +240,10 @@ struct hda_codec {
unsigned int single_adc_amp:1; /* adc in-amp takes no index
* (e.g. CX20549 codec)
*/
+ unsigned int hdmi_intr_trig_ctrl:1; /* hdmi interrupt trigger
+ * control flag
+ * (e.g. Nvidia codecs)
+ */
unsigned int no_sticky_stream:1; /* no sticky-PCM stream assignment */
unsigned int pins_shutup:1; /* pins are shut up */
unsigned int no_trigger_sense:1; /* don't trigger at pin-sensing */
diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c
index 879f886d2406..f0e87e39c53e 100644
--- a/sound/pci/hda/patch_hdmi.c
+++ b/sound/pci/hda/patch_hdmi.c
@@ -3721,8 +3721,11 @@ static int patch_nvhdmi_legacy(struct hda_codec *codec)
* +-----------------------------------|
*
* Note that for the trigger bit to take effect it needs to change value
- * (i.e. it needs to be toggled).
+ * (i.e. it needs to be toggled). The trigger bit is not applicable from
+ * TEGRA234 chip onwards, as new verb id 0xf80 will be used for interrupt
+ * trigger to hdmi.
*/
+#define NVIDIA_SET_HOST_INTR 0xf80
#define NVIDIA_GET_SCRATCH0 0xfa6
#define NVIDIA_SET_SCRATCH0_BYTE0 0xfa7
#define NVIDIA_SET_SCRATCH0_BYTE1 0xfa8
@@ -3741,25 +3744,37 @@ static int patch_nvhdmi_legacy(struct hda_codec *codec)
* The format parameter is the HDA audio format (see AC_FMT_*). If set to 0,
* the format is invalidated so that the HDMI codec can be disabled.
*/
-static void tegra_hdmi_set_format(struct hda_codec *codec, unsigned int format)
+static void tegra_hdmi_set_format(struct hda_codec *codec,
+ hda_nid_t cvt_nid,
+ unsigned int format)
{
unsigned int value;
+ unsigned int nid = NVIDIA_AFG_NID;
+
+ /*
+ * Tegra HDA codec design from TEGRA234 chip onwards support DP MST.
+ * This resulted in moving scratch registers from audio function
+ * group to converter widget context. So CVT NID should be used for
+ * scratch register read/write for DP MST supported Tegra HDA codec.
+ */
+ if (codec->dp_mst)
+ nid = cvt_nid;

/* bits [31:30] contain the trigger and valid bits */
- value = snd_hda_codec_read(codec, NVIDIA_AFG_NID, 0,
+ value = snd_hda_codec_read(codec, nid, 0,
NVIDIA_GET_SCRATCH0, 0);
value = (value >> 24) & 0xff;

/* bits [15:0] are used to store the HDA format */
- snd_hda_codec_write(codec, NVIDIA_AFG_NID, 0,
+ snd_hda_codec_write(codec, nid, 0,
NVIDIA_SET_SCRATCH0_BYTE0,
(format >> 0) & 0xff);
- snd_hda_codec_write(codec, NVIDIA_AFG_NID, 0,
+ snd_hda_codec_write(codec, nid, 0,
NVIDIA_SET_SCRATCH0_BYTE1,
(format >> 8) & 0xff);

/* bits [16:24] are unused */
- snd_hda_codec_write(codec, NVIDIA_AFG_NID, 0,
+ snd_hda_codec_write(codec, nid, 0,
NVIDIA_SET_SCRATCH0_BYTE2, 0);

/*
@@ -3771,15 +3786,28 @@ static void tegra_hdmi_set_format(struct hda_codec *codec, unsigned int format)
else
value |= NVIDIA_SCRATCH_VALID;

- /*
- * Whenever the trigger bit is toggled, an interrupt is raised in the
- * HDMI codec. The HDMI driver will use that as trigger to update its
- * configuration.
- */
- value ^= NVIDIA_SCRATCH_TRIGGER;
+ if (codec->hdmi_intr_trig_ctrl) {
+ /*
+ * For Tegra HDA Codec design from TEGRA234 onwards, the
+ * Interrupt to hdmi driver is triggered by writing
+ * non-zero values to verb 0xF80 instead of 31st bit of
+ * scratch register.
+ */
+ snd_hda_codec_write(codec, nid, 0,
+ NVIDIA_SET_SCRATCH0_BYTE3, value);
+ snd_hda_codec_write(codec, nid, 0,
+ NVIDIA_SET_HOST_INTR, 0x1);
+ } else {
+ /*
+ * Whenever the 31st trigger bit is toggled, an interrupt is raised
+ * in the HDMI codec. The HDMI driver will use that as trigger
+ * to update its configuration.
+ */
+ value ^= NVIDIA_SCRATCH_TRIGGER;

- snd_hda_codec_write(codec, NVIDIA_AFG_NID, 0,
- NVIDIA_SET_SCRATCH0_BYTE3, value);
+ snd_hda_codec_write(codec, nid, 0,
+ NVIDIA_SET_SCRATCH0_BYTE3, value);
+ }
}

static int tegra_hdmi_pcm_prepare(struct hda_pcm_stream *hinfo,
@@ -3796,7 +3824,7 @@ static int tegra_hdmi_pcm_prepare(struct hda_pcm_stream *hinfo,
return err;

/* notify the HDMI codec of the format change */
- tegra_hdmi_set_format(codec, format);
+ tegra_hdmi_set_format(codec, hinfo->nid, format);

return 0;
}
@@ -3806,7 +3834,7 @@ static int tegra_hdmi_pcm_cleanup(struct hda_pcm_stream *hinfo,
struct snd_pcm_substream *substream)
{
/* invalidate the format in the HDMI codec */
- tegra_hdmi_set_format(codec, 0);
+ tegra_hdmi_set_format(codec, hinfo->nid, 0);

return generic_hdmi_playback_pcm_cleanup(hinfo, codec, substream);
}
@@ -3903,6 +3931,7 @@ static int patch_tegra234_hdmi(struct hda_codec *codec)

codec->dp_mst = true;
codec->mst_no_extra_pcms = true;
+ codec->hdmi_intr_trig_ctrl = true;
spec = codec->spec;
spec->dyn_pin_out = true;
spec->dyn_pcm_assign = true;
--
2.17.1