1 files changed, 174 insertions, 13 deletions

diff --git a/drivers/dma/xilinx/xdma.c b/drivers/dma/xilinx/xdma.c
index e0bfd129d563..84a88029226f 100644
--- a/drivers/dma/xilinx/xdma.c
+++ b/drivers/dma/xilinx/xdma.c
@@ -83,6 +83,9 @@ struct xdma_chan {
  * @dblk_num: Number of hardware descriptor blocks
  * @desc_num: Number of hardware descriptors
  * @completed_desc_num: Completed hardware descriptors
+ * @cyclic: Cyclic transfer vs. scatter-gather
+ * @periods: Number of periods in the cyclic transfer
+ * @period_size: Size of a period in bytes in cyclic transfers
  */
 struct xdma_desc {
 	struct virt_dma_desc		vdesc;
@@ -93,6 +96,9 @@ struct xdma_desc {
 	u32				dblk_num;
 	u32				desc_num;
 	u32				completed_desc_num;
+	bool				cyclic;
+	u32				periods;
+	u32				period_size;
 };
 
 #define XDMA_DEV_STATUS_REG_DMA		BIT(0)
@@ -137,10 +143,10 @@ static inline void *xdma_blk_last_desc(struct xdma_desc_block *block)
 }
 
 /**
- * xdma_link_desc_blocks - Link descriptor blocks for DMA transfer
+ * xdma_link_sg_desc_blocks - Link SG descriptor blocks for DMA transfer
  * @sw_desc: Tx descriptor pointer
  */
-static void xdma_link_desc_blocks(struct xdma_desc *sw_desc)
+static void xdma_link_sg_desc_blocks(struct xdma_desc *sw_desc)
 {
 	struct xdma_desc_block *block;
 	u32 last_blk_desc, desc_control;
@@ -174,6 +180,25 @@ static void xdma_link_desc_blocks(struct xdma_desc *sw_desc)
 	desc->control = cpu_to_le32(XDMA_DESC_CONTROL_LAST);
 }
 
+/**
+ * xdma_link_cyclic_desc_blocks - Link cyclic descriptor blocks for DMA transfer
+ * @sw_desc: Tx descriptor pointer
+ */
+static void xdma_link_cyclic_desc_blocks(struct xdma_desc *sw_desc)
+{
+	struct xdma_desc_block *block;
+	struct xdma_hw_desc *desc;
+	int i;
+
+	block = sw_desc->desc_blocks;
+	for (i = 0; i < sw_desc->desc_num - 1; i++) {
+		desc = block->virt_addr + i * XDMA_DESC_SIZE;
+		desc->next_desc = cpu_to_le64(block->dma_addr + ((i + 1) * XDMA_DESC_SIZE));
+	}
+	desc = block->virt_addr + i * XDMA_DESC_SIZE;
+	desc->next_desc = cpu_to_le64(block->dma_addr);
+}
+
 static inline struct xdma_chan *to_xdma_chan(struct dma_chan *chan)
 {
 	return container_of(chan, struct xdma_chan, vchan.chan);
@@ -231,14 +256,16 @@ static void xdma_free_desc(struct virt_dma_desc *vdesc)
  * xdma_alloc_desc - Allocate descriptor
  * @chan: DMA channel pointer
  * @desc_num: Number of hardware descriptors
+ * @cyclic: Whether this is a cyclic transfer
  */
 static struct xdma_desc *
-xdma_alloc_desc(struct xdma_chan *chan, u32 desc_num)
+xdma_alloc_desc(struct xdma_chan *chan, u32 desc_num, bool cyclic)
 {
 	struct xdma_desc *sw_desc;
 	struct xdma_hw_desc *desc;
 	dma_addr_t dma_addr;
 	u32 dblk_num;
+	u32 control;
 	void *addr;
 	int i, j;
 
@@ -248,12 +275,18 @@ xdma_alloc_desc(struct xdma_chan *chan, u32 desc_num)
 
 	sw_desc->chan = chan;
 	sw_desc->desc_num = desc_num;
+	sw_desc->cyclic = cyclic;
 	dblk_num = DIV_ROUND_UP(desc_num, XDMA_DESC_ADJACENT);
 	sw_desc->desc_blocks = kcalloc(dblk_num, sizeof(*sw_desc->desc_blocks),
 				       GFP_NOWAIT);
 	if (!sw_desc->desc_blocks)
 		goto failed;
 
+	if (cyclic)
+		control = XDMA_DESC_CONTROL_CYCLIC;
+	else
+		control = XDMA_DESC_CONTROL(1, 0);
+
 	sw_desc->dblk_num = dblk_num;
 	for (i = 0; i < sw_desc->dblk_num; i++) {
 		addr = dma_pool_alloc(chan->desc_pool, GFP_NOWAIT, &dma_addr);
@@ -263,10 +296,13 @@ xdma_alloc_desc(struct xdma_chan *chan, u32 desc_num)
 		sw_desc->desc_blocks[i].virt_addr = addr;
 		sw_desc->desc_blocks[i].dma_addr = dma_addr;
 		for (j = 0, desc = addr; j < XDMA_DESC_ADJACENT; j++)
-			desc[j].control = cpu_to_le32(XDMA_DESC_CONTROL(1, 0));
+			desc[j].control = cpu_to_le32(control);
 	}
 
-	xdma_link_desc_blocks(sw_desc);
+	if (cyclic)
+		xdma_link_cyclic_desc_blocks(sw_desc);
+	else
+		xdma_link_sg_desc_blocks(sw_desc);
 
 	return sw_desc;
 
@@ -466,7 +502,7 @@ xdma_prep_device_sg(struct dma_chan *chan, struct scatterlist *sgl,
 	for_each_sg(sgl, sg, sg_len, i)
 		desc_num += DIV_ROUND_UP(sg_dma_len(sg), XDMA_DESC_BLEN_MAX);
 
-	sw_desc = xdma_alloc_desc(xdma_chan, desc_num);
+	sw_desc = xdma_alloc_desc(xdma_chan, desc_num, false);
 	if (!sw_desc)
 		return NULL;
 	sw_desc->dir = dir;
@@ -522,6 +558,81 @@ failed:
 }
 
 /**
+ * xdma_prep_dma_cyclic - prepare for cyclic DMA transactions
+ * @chan: DMA channel pointer
+ * @address: Device DMA address to access
+ * @size: Total length to transfer
+ * @period_size: Period size to use for each transfer
+ * @dir: Transfer direction
+ * @flags: Transfer ack flags
+ */
+static struct dma_async_tx_descriptor *
+xdma_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t address,
+		     size_t size, size_t period_size,
+		     enum dma_transfer_direction dir,
+		     unsigned long flags)
+{
+	struct xdma_chan *xdma_chan = to_xdma_chan(chan);
+	struct xdma_device *xdev = xdma_chan->xdev_hdl;
+	unsigned int periods = size / period_size;
+	struct dma_async_tx_descriptor *tx_desc;
+	struct xdma_desc_block *dblk;
+	struct xdma_hw_desc *desc;
+	struct xdma_desc *sw_desc;
+	unsigned int i;
+
+	/*
+	 * Simplify the whole logic by preventing an abnormally high number of
+	 * periods and periods size.
+	 */
+	if (period_size > XDMA_DESC_BLEN_MAX) {
+		xdma_err(xdev, "period size limited to %lu bytes\n", XDMA_DESC_BLEN_MAX);
+		return NULL;
+	}
+
+	if (periods > XDMA_DESC_ADJACENT) {
+		xdma_err(xdev, "number of periods limited to %u\n", XDMA_DESC_ADJACENT);
+		return NULL;
+	}
+
+	sw_desc = xdma_alloc_desc(xdma_chan, periods, true);
+	if (!sw_desc)
+		return NULL;
+
+	sw_desc->periods = periods;
+	sw_desc->period_size = period_size;
+	sw_desc->dir = dir;
+
+	dblk = sw_desc->desc_blocks;
+	desc = dblk->virt_addr;
+
+	/* fill hardware descriptor */
+	for (i = 0; i < periods; i++) {
+		desc->bytes = cpu_to_le32(period_size);
+		if (dir == DMA_MEM_TO_DEV) {
+			desc->src_addr = cpu_to_le64(address + i * period_size);
+			desc->dst_addr = cpu_to_le64(xdma_chan->cfg.dst_addr);
+		} else {
+			desc->src_addr = cpu_to_le64(xdma_chan->cfg.src_addr);
+			desc->dst_addr = cpu_to_le64(address + i * period_size);
+		}
+
+		desc++;
+	}
+
+	tx_desc = vchan_tx_prep(&xdma_chan->vchan, &sw_desc->vdesc, flags);
+	if (!tx_desc)
+		goto failed;
+
+	return tx_desc;
+
+failed:
+	xdma_free_desc(&sw_desc->vdesc);
+
+	return NULL;
+}
+
+/**
  * xdma_device_config - Configure the DMA channel
  * @chan: DMA channel
  * @cfg: channel configuration
@@ -577,6 +688,41 @@ static int xdma_alloc_chan_resources(struct dma_chan *chan)
 	return 0;
 }
 
+static enum dma_status xdma_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
+				      struct dma_tx_state *state)
+{
+	struct xdma_chan *xdma_chan = to_xdma_chan(chan);
+	struct xdma_desc *desc = NULL;
+	struct virt_dma_desc *vd;
+	enum dma_status ret;
+	unsigned long flags;
+	unsigned int period_idx;
+	u32 residue = 0;
+
+	ret = dma_cookie_status(chan, cookie, state);
+	if (ret == DMA_COMPLETE)
+		return ret;
+
+	spin_lock_irqsave(&xdma_chan->vchan.lock, flags);
+
+	vd = vchan_find_desc(&xdma_chan->vchan, cookie);
+	if (vd)
+		desc = to_xdma_desc(vd);
+	if (!desc || !desc->cyclic) {
+		spin_unlock_irqrestore(&xdma_chan->vchan.lock, flags);
+		return ret;
+	}
+
+	period_idx = desc->completed_desc_num % desc->periods;
+	residue = (desc->periods - period_idx) * desc->period_size;
+
+	spin_unlock_irqrestore(&xdma_chan->vchan.lock, flags);
+
+	dma_set_residue(state, residue);
+
+	return ret;
+}
+
 /**
  * xdma_channel_isr - XDMA channel interrupt handler
  * @irq: IRQ number
@@ -590,6 +736,7 @@ static irqreturn_t xdma_channel_isr(int irq, void *dev_id)
 	struct virt_dma_desc *vd;
 	struct xdma_desc *desc;
 	int ret;
+	u32 st;
 
 	spin_lock(&xchan->vchan.lock);
 
@@ -608,6 +755,19 @@ static irqreturn_t xdma_channel_isr(int irq, void *dev_id)
 		goto out;
 
 	desc->completed_desc_num += complete_desc_num;
+
+	if (desc->cyclic) {
+		ret = regmap_read(xdev->rmap, xchan->base + XDMA_CHAN_STATUS,
+				  &st);
+		if (ret)
+			goto out;
+
+		regmap_write(xdev->rmap, xchan->base + XDMA_CHAN_STATUS, st);
+
+		vchan_cyclic_callback(vd);
+		goto out;
+	}
+
 	/*
 	 * if all data blocks are transferred, remove and complete the request
 	 */
@@ -621,7 +781,7 @@ static irqreturn_t xdma_channel_isr(int irq, void *dev_id)
 	    complete_desc_num != XDMA_DESC_BLOCK_NUM * XDMA_DESC_ADJACENT)
 		goto out;
 
-	/* transfer the rest of data */
+	/* transfer the rest of data (SG only) */
 	xdma_xfer_start(xchan);
 
 out:
@@ -841,7 +1001,7 @@ EXPORT_SYMBOL(xdma_get_user_irq);
  * xdma_remove - Driver remove function
  * @pdev: Pointer to the platform_device structure
  */
-static int xdma_remove(struct platform_device *pdev)
+static void xdma_remove(struct platform_device *pdev)
 {
 	struct xdma_device *xdev = platform_get_drvdata(pdev);
 
@@ -850,8 +1010,6 @@ static int xdma_remove(struct platform_device *pdev)
 
 	if (xdev->status & XDMA_DEV_STATUS_REG_DMA)
 		dma_async_device_unregister(&xdev->dma_dev);
-
-	return 0;
 }
 
 /**
@@ -885,7 +1043,7 @@ static int xdma_probe(struct platform_device *pdev)
 		goto failed;
 	}
 	xdev->irq_start = res->start;
-	xdev->irq_num = res->end - res->start + 1;
+	xdev->irq_num = resource_size(res);
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!res) {
@@ -921,17 +1079,20 @@ static int xdma_probe(struct platform_device *pdev)
 
 	dma_cap_set(DMA_SLAVE, xdev->dma_dev.cap_mask);
 	dma_cap_set(DMA_PRIVATE, xdev->dma_dev.cap_mask);
+	dma_cap_set(DMA_CYCLIC, xdev->dma_dev.cap_mask);
 
 	xdev->dma_dev.dev = &pdev->dev;
+	xdev->dma_dev.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
 	xdev->dma_dev.device_free_chan_resources = xdma_free_chan_resources;
 	xdev->dma_dev.device_alloc_chan_resources = xdma_alloc_chan_resources;
-	xdev->dma_dev.device_tx_status = dma_cookie_status;
+	xdev->dma_dev.device_tx_status = xdma_tx_status;
 	xdev->dma_dev.device_prep_slave_sg = xdma_prep_device_sg;
 	xdev->dma_dev.device_config = xdma_device_config;
 	xdev->dma_dev.device_issue_pending = xdma_issue_pending;
 	xdev->dma_dev.filter.map = pdata->device_map;
 	xdev->dma_dev.filter.mapcnt = pdata->device_map_cnt;
 	xdev->dma_dev.filter.fn = xdma_filter_fn;
+	xdev->dma_dev.device_prep_dma_cyclic = xdma_prep_dma_cyclic;
 
 	ret = dma_async_device_register(&xdev->dma_dev);
 	if (ret) {
@@ -966,7 +1127,7 @@ static struct platform_driver xdma_driver = {
 	},
 	.id_table	= xdma_id_table,
 	.probe		= xdma_probe,
-	.remove		= xdma_remove,
+	.remove_new	= xdma_remove,
 };
 
 module_platform_driver(xdma_driver);