ASoC: Intel: Skylake: Add deep buffer support

With this patch, the dma buffer size is fetched from topology binary. This
buffer size is applicable for gateway copier modules.

Now that we can configure DSP dma buffer size, the device can support deep
buffer playback. DSP fetches large buffer and can result fewer wakes,
which helps in power reduction.

Signed-off-by: Ramesh Babu <ramesh.babu@intel.com>
Signed-off-by: Subhransu S. Prusty <subhransu.s.prusty@intel.com>
Acked-By: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

include/uapi/sound/snd_sst_tokens.h

@@ -161,6 +161,8 @@
  *
  * %SKL_TKL_U32_D0I3_CAPS:	Specifies the D0i3 capability for module
  *
+ * %SKL_TKN_U32_DMA_BUF_SIZE:	DMA buffer size in millisec
+ *
  * module_id and loadable flags dont have tokens as these values will be
  * read from the DSP FW manifest
  */
@@ -215,7 +217,8 @@ enum SKL_TKNS {
 	SKL_TKN_U32_PMODE,
 	SKL_TKL_U32_D0I3_CAPS, /* Typo added at v4.10 */
 	SKL_TKN_U32_D0I3_CAPS = SKL_TKL_U32_D0I3_CAPS,
-	SKL_TKN_MAX = SKL_TKN_U32_D0I3_CAPS,
+	SKL_TKN_U32_DMA_BUF_SIZE,
+	SKL_TKN_MAX = SKL_TKN_U32_DMA_BUF_SIZE,
 };
 
 #endif

sound/soc/intel/skylake/skl-topology.c

@@ -2212,6 +2212,10 @@ static int skl_tplg_get_token(struct device *dev,
 
 		break;
 
+	case SKL_TKN_U32_DMA_BUF_SIZE:
+		mconfig->dma_buffer_size = tkn_elem->value;
+		break;
+
 	case SKL_TKN_U8_IN_PIN_TYPE:
 	case SKL_TKN_U8_OUT_PIN_TYPE:
 	case SKL_TKN_U8_CONN_TYPE:

sound/soc/intel/skylake/skl-topology.h

@@ -321,6 +321,7 @@ struct skl_module_cfg {
 	u32 vbus_id;
 	u32 mem_pages;
 	enum d0i3_capability d0i3_caps;
+	u32 dma_buffer_size; /* in milli seconds */
 	struct skl_module_pin *m_in_pin;
 	struct skl_module_pin *m_out_pin;
 	enum skl_module_type m_type;