[PATCH v3 2/5] soc: qcom: geni: Add support for gpi dma

[Vinod Koul <vkoul@xxxxxxxxxx>]

GPI DMA is one of the DMA modes supported on geni, this adds support to
enable that mode

Also do better documentation of the enum geni_se_xfer_mode.

Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx>
---
 drivers/soc/qcom/qcom-geni-se.c | 29 ++++++++++++++++++++++++++++-
 include/linux/qcom-geni-se.h    | 15 ++++++++++++++-
 2 files changed, 42 insertions(+), 2 deletions(-)

diff --git a/drivers/soc/qcom/qcom-geni-se.c b/drivers/soc/qcom/qcom-geni-se.c
index fe666ea0c487..7d649d2cf31e 100644
--- a/drivers/soc/qcom/qcom-geni-se.c
+++ b/drivers/soc/qcom/qcom-geni-se.c
@@ -321,6 +321,30 @@ static void geni_se_select_dma_mode(struct geni_se *se)
 		writel_relaxed(val, se->base + SE_GENI_DMA_MODE_EN);
 }
 
+static void geni_se_select_gpi_mode(struct geni_se *se)
+{
+	u32 val;
+
+	geni_se_irq_clear(se);
+
+	writel(0, se->base + SE_IRQ_EN);
+
+	val = readl(se->base + SE_GENI_S_IRQ_EN);
+	val &= ~S_CMD_DONE_EN;
+	writel(val, se->base + SE_GENI_S_IRQ_EN);
+
+	val = readl(se->base + SE_GENI_M_IRQ_EN);
+	val &= ~(M_CMD_DONE_EN | M_TX_FIFO_WATERMARK_EN |
+		 M_RX_FIFO_WATERMARK_EN | M_RX_FIFO_LAST_EN);
+	writel(val, se->base + SE_GENI_M_IRQ_EN);
+
+	writel(GENI_DMA_MODE_EN, se->base + SE_GENI_DMA_MODE_EN);
+
+	val = readl(se->base + SE_GSI_EVENT_EN);
+	val |= (DMA_RX_EVENT_EN | DMA_TX_EVENT_EN | GENI_M_EVENT_EN | GENI_S_EVENT_EN);
+	writel(val, se->base + SE_GSI_EVENT_EN);
+}
+
 /**
  * geni_se_select_mode() - Select the serial engine transfer mode
  * @se:		Pointer to the concerned serial engine.
@@ -328,7 +352,7 @@ static void geni_se_select_dma_mode(struct geni_se *se)
  */
 void geni_se_select_mode(struct geni_se *se, enum geni_se_xfer_mode mode)
 {
-	WARN_ON(mode != GENI_SE_FIFO && mode != GENI_SE_DMA);
+	WARN_ON(mode != GENI_SE_FIFO && mode != GENI_SE_DMA && mode != GENI_GPI_DMA);
 
 	switch (mode) {
 	case GENI_SE_FIFO:
@@ -337,6 +361,9 @@ void geni_se_select_mode(struct geni_se *se, enum geni_se_xfer_mode mode)
 	case GENI_SE_DMA:
 		geni_se_select_dma_mode(se);
 		break;
+	case GENI_GPI_DMA:
+		geni_se_select_gpi_mode(se);
+		break;
 	case GENI_SE_INVALID:
 	default:
 		break;
diff --git a/include/linux/qcom-geni-se.h b/include/linux/qcom-geni-se.h
index 5114e2144b17..f5672785c0c4 100644
--- a/include/linux/qcom-geni-se.h
+++ b/include/linux/qcom-geni-se.h
@@ -8,11 +8,24 @@
 
 #include <linux/interconnect.h>
 
-/* Transfer mode supported by GENI Serial Engines */
+/**
+ * enum geni_se_xfer_mode: Transfer modes supported by Serial Engines
+ *
+ * @GENI_SE_INVALID: Invalid mode
+ * @GENI_SE_FIFO: FIFO mode. Data is transferred with SE FIFO
+ * by programmed IO method
+ * @GENI_SE_DMA: Serial Engine DMA mode. Data is transferred
+ * with SE by DMAengine internal to SE
+ * @GENI_GPI_DMA: GPI DMA mode. Data is transferred using a DMAengine
+ * configured by a firmware residing on a GSI engine. This DMA name is
+ * interchangeably used as GSI or GPI which seem to imply the same DMAengine
+ */
+
 enum geni_se_xfer_mode {
 	GENI_SE_INVALID,
 	GENI_SE_FIFO,
 	GENI_SE_DMA,
+	GENI_GPI_DMA,
 };
 
 /* Protocols supported by GENI Serial Engines */
-- 
2.31.1