ASoC: SOF: Intel: mtl: add get_stream_position support

Get HDaudio link position for current stream delay calculation
from hda registers.
Signed-off-by: Rander Wang <rander.wang@intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
Link: https://lore.kernel.org/r/20230202132954.26773-9-peter.ujfalusi@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/sof/intel/mtl.c

@@ -581,6 +581,18 @@ static int mtl_dsp_disable_interrupts(struct snd_sof_dev *sdev)
 	return mtl_enable_interrupts(sdev, false);
 }
 
+static u64 mtl_dsp_get_stream_hda_link_position(struct snd_sof_dev *sdev,
+						struct snd_soc_component *component,
+						struct snd_pcm_substream *substream)
+{
+	struct hdac_stream *hstream = substream->runtime->private_data;
+	u32 llp_l, llp_u;
+
+	llp_l = snd_sof_dsp_read(sdev, HDA_DSP_HDA_BAR, MTL_PPLCLLPL(hstream->index));
+	llp_u = snd_sof_dsp_read(sdev, HDA_DSP_HDA_BAR, MTL_PPLCLLPU(hstream->index));
+	return ((u64)llp_u << 32) | llp_l;
+}
+
 /* Meteorlake ops */
 struct snd_sof_dsp_ops sof_mtl_ops;
 EXPORT_SYMBOL_NS(sof_mtl_ops, SND_SOC_SOF_INTEL_HDA_COMMON);
@@ -619,6 +631,8 @@ int sof_mtl_ops_init(struct snd_sof_dev *sdev)
 	/* dsp core get/put */
 	/* TODO: add core_get and core_put */
 
+	sof_mtl_ops.get_stream_position = mtl_dsp_get_stream_hda_link_position;
+
 	sdev->private = devm_kzalloc(sdev->dev, sizeof(struct sof_ipc4_fw_data), GFP_KERNEL);
 	if (!sdev->private)
 		return -ENOMEM;

sound/soc/sof/intel/mtl.h

@@ -6,6 +6,12 @@
  * Copyright(c) 2020-2022 Intel Corporation. All rights reserved.
  */
 
+/* HDA Registers */
+#define MTL_PPLCLLPL_BASE		0x948
+#define MTL_PPLCLLPU_STRIDE		0x10
+#define MTL_PPLCLLPL(x)			(MTL_PPLCLLPL_BASE + (x) * MTL_PPLCLLPU_STRIDE)
+#define MTL_PPLCLLPU(x)			(MTL_PPLCLLPL_BASE + 0x4 + (x) * MTL_PPLCLLPU_STRIDE)
+
 /* DSP Registers */
 #define MTL_HFDSSCS			0x1000
 #define MTL_HFDSSCS_SPA_MASK		BIT(16)