[PATCH] dmaengine: dw-edma: Add Simple Mode Support

[Devendra K Verma <devverma@amd.com>]

The HDMA IP supports the simple mode (non-linked list).
In this mode the channel registers are configured to initiate
a single DMA data transfer. The channel can be configured in
simple mode via peripheral param of dma_slave_config param.

Signed-off-by: Devendra K Verma <devverma@amd.com>
---
 drivers/dma/dw-edma/dw-edma-core.c    | 10 +++++
 drivers/dma/dw-edma/dw-edma-core.h    |  2 +
 drivers/dma/dw-edma/dw-hdma-v0-core.c | 53 ++++++++++++++++++++++++++-
 include/linux/dma/edma.h              |  8 ++++
 4 files changed, 72 insertions(+), 1 deletion(-)

diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c
index c2b88cc99e5d..4dafd6554277 100644
--- a/drivers/dma/dw-edma/dw-edma-core.c
+++ b/drivers/dma/dw-edma/dw-edma-core.c
@@ -235,9 +235,19 @@ static int dw_edma_device_config(struct dma_chan *dchan,
 				 struct dma_slave_config *config)
 {
 	struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan);
+	struct dw_edma_peripheral_config *pconfig = config->peripheral_config;
+	unsigned long flags;
+
+	if (WARN_ON(config->peripheral_config &&
+		    config->peripheral_size != sizeof(*pconfig)))
+		return -EINVAL;
 
+	spin_lock_irqsave(&chan->vc.lock, flags);
 	memcpy(&chan->config, config, sizeof(*config));
+
+	chan->non_ll_en = pconfig ? pconfig->non_ll_en : false;
 	chan->configured = true;
+	spin_unlock_irqrestore(&chan->vc.lock, flags);
 
 	return 0;
 }
diff --git a/drivers/dma/dw-edma/dw-edma-core.h b/drivers/dma/dw-edma/dw-edma-core.h
index 71894b9e0b15..c0266976aa22 100644
--- a/drivers/dma/dw-edma/dw-edma-core.h
+++ b/drivers/dma/dw-edma/dw-edma-core.h
@@ -86,6 +86,8 @@ struct dw_edma_chan {
 	u8				configured;
 
 	struct dma_slave_config		config;
+
+	bool				non_ll_en;
 };
 
 struct dw_edma_irq {
diff --git a/drivers/dma/dw-edma/dw-hdma-v0-core.c b/drivers/dma/dw-edma/dw-hdma-v0-core.c
index e3f8db4fe909..3237c807a18e 100644
--- a/drivers/dma/dw-edma/dw-hdma-v0-core.c
+++ b/drivers/dma/dw-edma/dw-hdma-v0-core.c
@@ -225,7 +225,7 @@ static void dw_hdma_v0_sync_ll_data(struct dw_edma_chunk *chunk)
 		readl(chunk->ll_region.vaddr.io);
 }
 
-static void dw_hdma_v0_core_start(struct dw_edma_chunk *chunk, bool first)
+static void dw_hdma_v0_ll_start(struct dw_edma_chunk *chunk, bool first)
 {
 	struct dw_edma_chan *chan = chunk->chan;
 	struct dw_edma *dw = chan->dw;
@@ -263,6 +263,57 @@ static void dw_hdma_v0_core_start(struct dw_edma_chunk *chunk, bool first)
 	SET_CH_32(dw, chan->dir, chan->id, doorbell, HDMA_V0_DOORBELL_START);
 }
 
+static void dw_hdma_v0_non_ll_start(struct dw_edma_chunk *chunk)
+{
+	struct dw_edma_chan *chan = chunk->chan;
+	struct dw_edma *dw = chan->dw;
+	struct dw_edma_burst *child;
+	u32 val;
+
+	list_for_each_entry(child, &chunk->burst->list, list) {
+		SET_CH_32(dw, chan->dir, chan->id, ch_en, BIT(0));
+
+		/* Source address */
+		SET_CH_32(dw, chan->dir, chan->id, sar.lsb, lower_32_bits(child->sar));
+		SET_CH_32(dw, chan->dir, chan->id, sar.msb, upper_32_bits(child->sar));
+
+		/* Destination address */
+		SET_CH_32(dw, chan->dir, chan->id, dar.lsb, lower_32_bits(child->dar));
+		SET_CH_32(dw, chan->dir, chan->id, dar.msb, upper_32_bits(child->dar));
+
+		/* Transfer size */
+		SET_CH_32(dw, chan->dir, chan->id, transfer_size, child->sz);
+
+		/* Interrupt setup */
+		val = GET_CH_32(dw, chan->dir, chan->id, int_setup) |
+				HDMA_V0_STOP_INT_MASK | HDMA_V0_ABORT_INT_MASK |
+				HDMA_V0_LOCAL_STOP_INT_EN | HDMA_V0_LOCAL_ABORT_INT_EN;
+
+		if (!(dw->chip->flags & DW_EDMA_CHIP_LOCAL))
+			val |= HDMA_V0_REMOTE_STOP_INT_EN | HDMA_V0_REMOTE_ABORT_INT_EN;
+
+		SET_CH_32(dw, chan->dir, chan->id, int_setup, val);
+
+		/* Channel control setup */
+		val = GET_CH_32(dw, chan->dir, chan->id, control1);
+		val &= ~HDMA_V0_LINKLIST_EN;
+		SET_CH_32(dw, chan->dir, chan->id, control1, val);
+
+		/* Ring the doorbell */
+		SET_CH_32(dw, chan->dir, chan->id, doorbell, HDMA_V0_DOORBELL_START);
+	}
+}
+
+static void dw_hdma_v0_core_start(struct dw_edma_chunk *chunk, bool first)
+{
+	struct dw_edma_chan *chan = chunk->chan;
+
+	if (!chan->non_ll_en)
+		dw_hdma_v0_ll_start(chunk, first);
+	else
+		dw_hdma_v0_non_ll_start(chunk);
+}
+
 static void dw_hdma_v0_core_ch_config(struct dw_edma_chan *chan)
 {
 	struct dw_edma *dw = chan->dw;
diff --git a/include/linux/dma/edma.h b/include/linux/dma/edma.h
index 3080747689f6..82d808013a66 100644
--- a/include/linux/dma/edma.h
+++ b/include/linux/dma/edma.h
@@ -101,6 +101,14 @@ struct dw_edma_chip {
 	struct dw_edma		*dw;
 };
 
+/**
+ * struct dw_edma_peripheral_config - peripheral spicific configurations
+ * @non_ll_en:		 enable non-linked list mode of operations
+ */
+struct dw_edma_peripheral_config {
+	bool			non_ll_en;
+};
+
 /* Export to the platform drivers */
 #if IS_REACHABLE(CONFIG_DW_EDMA)
 int dw_edma_probe(struct dw_edma_chip *chip);
-- 
2.43.0