ASoC: SOF: Add DMIC token for unmute gain ramp time

The settling time of DMIC DC level is both platform and used
microphone model specific. The unmute gain ramp is used to conceal
most of the large DC level seen in beginning of capture. This patch
adds into the DMIC DAI IPC struct a new field called unmute_ramp_time
and a new token SOF_TKN_INTEL_DMIC_UNMUTE_RAMP_TIME. The value is the
ramp length in milliseconds (ms).

The ABI minor version is incremented for this backwards compatible
change.
Signed-off-by: Seppo Ingalsuo <seppo.ingalsuo@linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

include/sound/sof/dai-intel.h

@@ -167,9 +167,10 @@ struct sof_ipc_dai_dmic_params {
 
 	uint32_t wake_up_time;      /**< Time from clock start to data (us) */
 	uint32_t min_clock_on_time; /**< Min. time that clk is kept on (us) */
+	uint32_t unmute_ramp_time;  /**< Length of logarithmic gain ramp (ms) */
 
 	/* reserved for future use */
-	uint32_t reserved[6];
+	uint32_t reserved[5];
 
 	/**< variable number of pdm controller config */
 	struct sof_ipc_dai_dmic_pdm_ctrl pdm[0];

include/uapi/sound/sof/abi.h

@@ -26,7 +26,7 @@
 
 /* SOF ABI version major, minor and patch numbers */
 #define SOF_ABI_MAJOR 3
-#define SOF_ABI_MINOR 7
+#define SOF_ABI_MINOR 8
 #define SOF_ABI_PATCH 0
 
 /* SOF ABI version number. Format within 32bit word is MMmmmppp */

include/uapi/sound/sof/tokens.h

@@ -85,6 +85,7 @@
 #define SOF_TKN_INTEL_DMIC_NUM_PDM_ACTIVE	605
 #define SOF_TKN_INTEL_DMIC_SAMPLE_RATE		608
 #define SOF_TKN_INTEL_DMIC_FIFO_WORD_LENGTH	609
+#define SOF_TKN_INTEL_DMIC_UNMUTE_RAMP_TIME_MS  610
 
 /* DMIC PDM */
 #define SOF_TKN_INTEL_DMIC_PDM_CTRL_ID		700

sound/soc/sof/topology.c

@@ -779,6 +779,10 @@ static const struct sof_topology_token dmic_tokens[] = {
 	{SOF_TKN_INTEL_DMIC_FIFO_WORD_LENGTH,
 		SND_SOC_TPLG_TUPLE_TYPE_SHORT, get_token_u16,
 		offsetof(struct sof_ipc_dai_dmic_params, fifo_bits), 0},
+	{SOF_TKN_INTEL_DMIC_UNMUTE_RAMP_TIME_MS,
+		SND_SOC_TPLG_TUPLE_TYPE_WORD, get_token_u32,
+		offsetof(struct sof_ipc_dai_dmic_params, unmute_ramp_time), 0},
+
 };
 
 /*