ALSA: hdac: Add support for hda DMA Resume capability

Skylake sports new capability of DMA resume, DRSM where we can
resume the DMA. This capability is defined by presence of
AZX_DRSM_CAP_ID.

If this capability is present, we use this capability.
So we add:

snd_hdac_ext_stream_drsm_enable() - DMA resume caps
snd_hdac_ext_stream_set_dpibr() - set the DMA position
snd_hdac_ext_stream_set_lpib() - set the lpib

Signed-off-by: Jeeja KP <jeeja.kp@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Mark Brown <broonie@kernel.org>

2 files changed, 77 insertions, 0 deletions

diff --git a/sound/hda/ext/hdac_ext_controller.c b/sound/hda/ext/hdac_ext_controller.c
index 63215b17247c..556267e75591 100644
--- a/sound/hda/ext/hdac_ext_controller.c
+++ b/sound/hda/ext/hdac_ext_controller.c
@@ -77,6 +77,12 @@ int snd_hdac_ext_bus_parse_capabilities(struct hdac_ext_bus *ebus)
 			ebus->spbcap = bus->remap_addr + offset;
 			break;
 
+		case AZX_DRSM_CAP_ID:
+			/* DMA resume  capability found, handler function */
+			dev_dbg(bus->dev, "Found DRSM capability\n");
+			ebus->drsmcap = bus->remap_addr + offset;
+			break;
+
 		default:
 			dev_dbg(bus->dev, "Unknown capability %d\n", cur_cap);
 			break;
diff --git a/sound/hda/ext/hdac_ext_stream.c b/sound/hda/ext/hdac_ext_stream.c
index cb89ec7c8147..8f30e8836818 100644
--- a/sound/hda/ext/hdac_ext_stream.c
+++ b/sound/hda/ext/hdac_ext_stream.c
@@ -59,6 +59,10 @@ void snd_hdac_ext_stream_init(struct hdac_ext_bus *ebus,
 					AZX_SPB_MAXFIFO;
 	}
 
+	if (ebus->drsmcap)
+		stream->dpibr_addr = ebus->drsmcap + AZX_DRSM_BASE +
+					AZX_DRSM_INTERVAL * idx;
+
 	stream->decoupled = false;
 	snd_hdac_stream_init(bus, &stream->hstream, idx, direction, tag);
 }
@@ -497,3 +501,70 @@ void snd_hdac_ext_stop_streams(struct hdac_ext_bus *ebus)
 	}
 }
 EXPORT_SYMBOL_GPL(snd_hdac_ext_stop_streams);
+
+/**
+ * snd_hdac_ext_stream_drsm_enable - enable DMA resume for a stream
+ * @ebus: HD-audio ext core bus
+ * @enable: flag to enable/disable DRSM
+ * @index: stream index for which DRSM need to be enabled
+ */
+void snd_hdac_ext_stream_drsm_enable(struct hdac_ext_bus *ebus,
+				bool enable, int index)
+{
+	u32 mask = 0;
+	u32 register_mask = 0;
+	struct hdac_bus *bus = &ebus->bus;
+
+	if (!ebus->drsmcap) {
+		dev_err(bus->dev, "Address of DRSM capability is NULL");
+		return;
+	}
+
+	mask |= (1 << index);
+
+	register_mask = readl(ebus->drsmcap + AZX_REG_SPB_SPBFCCTL);
+
+	mask |= register_mask;
+
+	if (enable)
+		snd_hdac_updatel(ebus->drsmcap, AZX_REG_DRSM_CTL, 0, mask);
+	else
+		snd_hdac_updatel(ebus->drsmcap, AZX_REG_DRSM_CTL, mask, 0);
+}
+EXPORT_SYMBOL_GPL(snd_hdac_ext_stream_drsm_enable);
+
+/**
+ * snd_hdac_ext_stream_set_dpibr - sets the dpibr value of a stream
+ * @ebus: HD-audio ext core bus
+ * @stream: hdac_ext_stream
+ * @value: dpib value to set
+ */
+int snd_hdac_ext_stream_set_dpibr(struct hdac_ext_bus *ebus,
+				 struct hdac_ext_stream *stream, u32 value)
+{
+	struct hdac_bus *bus = &ebus->bus;
+
+	if (!ebus->drsmcap) {
+		dev_err(bus->dev, "Address of DRSM capability is NULL");
+		return -EINVAL;
+	}
+
+	writel(value, stream->dpibr_addr);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_hdac_ext_stream_set_dpibr);
+
+/**
+ * snd_hdac_ext_stream_set_lpib - sets the lpib value of a stream
+ * @ebus: HD-audio ext core bus
+ * @stream: hdac_ext_stream
+ * @value: lpib value to set
+ */
+int snd_hdac_ext_stream_set_lpib(struct hdac_ext_stream *stream, u32 value)
+{
+	snd_hdac_stream_writel(&stream->hstream, SD_LPIB, value);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_hdac_ext_stream_set_lpib);