ASoC: SOF: core/Intel: Handle pause supported token

Merge series from Peter Ujfalusi <[e-mail]>:

A new set of tokens have been added to SOF topology to indicate that the pause
operation is supported or not on the given PCM device.
Pause is an optional feature that depends on pipeline, topology and modules
used by the PCM.

Add a pause_supported flag to snd_sof_pcm_stream and use this flag in Intel
platform code to keep the pause support enabled or to disable it.

include/uapi/sound/sof/tokens.h

···
 /* Stream */
 #define SOF_TKN_STREAM_PLAYBACK_COMPATIBLE_D0I3	1200
 #define SOF_TKN_STREAM_CAPTURE_COMPATIBLE_D0I3	1201
+#define SOF_TKN_STREAM_PLAYBACK_PAUSE_SUPPORTED	1202
+#define SOF_TKN_STREAM_CAPTURE_PAUSE_SUPPORTED	1203
 
 /* Led control for mute switches */
 #define SOF_TKN_MUTE_LED_USE			1300

sound/soc/sof/intel/hda-pcm.c

···
 module_param_named(disable_rewinds, hda_disable_rewinds, bool, 0444);
 MODULE_PARM_DESC(disable_rewinds, "SOF HDA disable rewinds");
 
+static int hda_force_pause_support = -1;
+module_param_named(force_pause_support, hda_force_pause_support, int, 0444);
+MODULE_PARM_DESC(force_pause_support,
+		 "Pause support: -1: Use default, 0: Disable, 1: Enable (default -1)");
+
 u32 hda_dsp_get_mult_div(struct snd_sof_dev *sdev, int rate)
 {
 	switch (rate) {
···
 	 * pause push/release to be disabled
 	 */
 	if (hda_always_enable_dmi_l1 && direction == SNDRV_PCM_STREAM_CAPTURE)
+		runtime->hw.info &= ~SNDRV_PCM_INFO_PAUSE;
+
+	/*
+	 * Do not advertise the PAUSE support if it is forced to be disabled via
+	 * module parameter or if the pause_supported is false for the PCM
+	 * device
+	 */
+	if (hda_force_pause_support == 0 ||
+	    (hda_force_pause_support == -1 &&
+	     !spcm->stream[substream->stream].pause_supported))
 		runtime->hw.info &= ~SNDRV_PCM_INFO_PAUSE;
 
 	if (hda_always_enable_dmi_l1 ||

sound/soc/sof/sof-audio.h

···
 	struct work_struct period_elapsed_work;
 	struct snd_soc_dapm_widget_list *list; /* list of connected DAPM widgets */
 	bool d0i3_compatible; /* DSP can be in D0I3 when this pcm is opened */
+	bool pause_supported; /* PCM device supports PAUSE operation */
 	unsigned int dsp_max_burst_size_in_ms; /* The maximum size of the host DMA burst in ms */
 	/*
 	 * flag to indicate that the DSP pipelines should be kept

sound/soc/sof/topology.c

···
 		offsetof(struct snd_sof_pcm, stream[0].d0i3_compatible)},
 	{SOF_TKN_STREAM_CAPTURE_COMPATIBLE_D0I3, SND_SOC_TPLG_TUPLE_TYPE_BOOL, get_token_u16,
 		offsetof(struct snd_sof_pcm, stream[1].d0i3_compatible)},
+	{SOF_TKN_STREAM_PLAYBACK_PAUSE_SUPPORTED, SND_SOC_TPLG_TUPLE_TYPE_BOOL, get_token_u16,
+		offsetof(struct snd_sof_pcm, stream[0].pause_supported)},
+	{SOF_TKN_STREAM_CAPTURE_PAUSE_SUPPORTED, SND_SOC_TPLG_TUPLE_TYPE_BOOL, get_token_u16,
+		offsetof(struct snd_sof_pcm, stream[1].pause_supported)},
 };
 
 /* Leds */