[PATCH v2 02/19] dmaengine: dw-edma: Add dw_edma_core_ll_clear() to clear LL control-word

[Koichiro Den]

Add a core operation for clearing the control word of one linked-list
entry. A later patch uses the operation to invalidate stale CB when
resetting a circular LL ring.

No functional change.

Signed-off-by: Koichiro Den <den@xxxxxxxxxxxxx>
---
Changes in v2:
  - Split the provider operation from "Clear LL data entries on reset".

 drivers/dma/dw-edma/dw-edma-core.h    |  6 ++++++
 drivers/dma/dw-edma/dw-edma-v0-core.c | 16 ++++++++++++++++
 drivers/dma/dw-edma/dw-hdma-v0-core.c | 16 ++++++++++++++++
 3 files changed, 38 insertions(+)

diff --git a/drivers/dma/dw-edma/dw-edma-core.h b/drivers/dma/dw-edma/dw-edma-core.h
index e50fa7965778..089f913fd247 100644
--- a/drivers/dma/dw-edma/dw-edma-core.h
+++ b/drivers/dma/dw-edma/dw-edma-core.h
@@ -138,6 +138,7 @@ struct dw_edma_core_ops {
 	void (*ll_data)(struct dw_edma_chan *chan, struct dw_edma_burst *burst,
 			u32 idx, bool cb, bool irq);
 	void (*ll_link)(struct dw_edma_chan *chan, u32 idx, bool cb, u64 addr);
+	void (*ll_clear)(struct dw_edma_chan *chan, u32 idx);
 	int (*ll_cur_idx)(struct dw_edma_chan *chan);
 	void (*ch_doorbell)(struct dw_edma_chan *chan);
 	void (*ch_enable)(struct dw_edma_chan *chan);
@@ -255,6 +256,11 @@ dw_edma_core_ll_link(struct dw_edma_chan *chan, u32 idx, bool cb, u64 addr)
 	chan->dw->core->ll_link(chan, idx, cb, addr);
 }
 
+static inline void dw_edma_core_ll_clear(struct dw_edma_chan *chan, u32 idx)
+{
+	chan->dw->core->ll_clear(chan, idx);
+}
+
 static inline void dw_edma_core_ch_doorbell(struct dw_edma_chan *chan)
 {
 	chan->dw->core->ch_doorbell(chan);
diff --git a/drivers/dma/dw-edma/dw-edma-v0-core.c b/drivers/dma/dw-edma/dw-edma-v0-core.c
index ba84811234e1..c31fff095b4f 100644
--- a/drivers/dma/dw-edma/dw-edma-v0-core.c
+++ b/drivers/dma/dw-edma/dw-edma-v0-core.c
@@ -605,6 +605,21 @@ dw_edma_v0_core_ll_link(struct dw_edma_chan *chan, u32 idx, bool cb, u64 addr)
 	dw_edma_v0_write_ll_link(chan, idx, control, addr);
 }
 
+static void dw_edma_v0_core_ll_clear(struct dw_edma_chan *chan, u32 idx)
+{
+	ptrdiff_t ofs = idx * sizeof(struct dw_edma_v0_lli);
+
+	if (chan->dw->chip->flags & DW_EDMA_CHIP_LOCAL) {
+		struct dw_edma_v0_lli *lli = chan->ll_region.vaddr.mem + ofs;
+
+		lli->control = 0;
+	} else {
+		struct dw_edma_v0_lli __iomem *lli = chan->ll_region.vaddr.io + ofs;
+
+		writel(0, &lli->control);
+	}
+}
+
 static void dw_edma_v0_core_ch_doorbell(struct dw_edma_chan *chan)
 {
 	struct dw_edma *dw = chan->dw;
@@ -668,6 +683,7 @@ static const struct dw_edma_core_ops dw_edma_v0_core = {
 	.handle_int = dw_edma_v0_core_handle_int,
 	.ll_data = dw_edma_v0_core_ll_data,
 	.ll_link = dw_edma_v0_core_ll_link,
+	.ll_clear = dw_edma_v0_core_ll_clear,
 	.ll_cur_idx = dw_edma_v0_core_ll_cur_idx,
 	.ch_doorbell = dw_edma_v0_core_ch_doorbell,
 	.ch_enable = dw_edma_v0_core_ch_enable,
diff --git a/drivers/dma/dw-edma/dw-hdma-v0-core.c b/drivers/dma/dw-edma/dw-hdma-v0-core.c
index 2fc7f8e85b43..b2d35f0b7b6d 100644
--- a/drivers/dma/dw-edma/dw-hdma-v0-core.c
+++ b/drivers/dma/dw-edma/dw-hdma-v0-core.c
@@ -374,6 +374,21 @@ dw_hdma_v0_core_ll_link(struct dw_edma_chan *chan, u32 idx, bool cb, u64 addr)
 	dw_hdma_v0_write_ll_link(chan, idx, control, addr);
 }
 
+static void dw_hdma_v0_core_ll_clear(struct dw_edma_chan *chan, u32 idx)
+{
+	ptrdiff_t ofs = idx * sizeof(struct dw_hdma_v0_lli);
+
+	if (chan->dw->chip->flags & DW_EDMA_CHIP_LOCAL) {
+		struct dw_hdma_v0_lli *lli = chan->ll_region.vaddr.mem + ofs;
+
+		lli->control = 0;
+	} else {
+		struct dw_hdma_v0_lli __iomem *lli = chan->ll_region.vaddr.io + ofs;
+
+		writel(0, &lli->control);
+	}
+}
+
 static void dw_hdma_v0_core_ch_doorbell(struct dw_edma_chan *chan)
 {
 	struct dw_edma *dw = chan->dw;
@@ -424,6 +439,7 @@ static const struct dw_edma_core_ops dw_hdma_v0_core = {
 	.non_ll_start = dw_hdma_v0_core_non_ll_start,
 	.ll_data = dw_hdma_v0_core_ll_data,
 	.ll_link = dw_hdma_v0_core_ll_link,
+	.ll_clear = dw_hdma_v0_core_ll_clear,
 	.ll_cur_idx = dw_hdma_v0_core_ll_cur_idx,
 	.ch_doorbell = dw_hdma_v0_core_ch_doorbell,
 	.ch_enable = dw_hdma_v0_core_ch_enable,
-- 
2.51.0