1 files changed, 237 insertions, 51 deletions

diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c
index 75c0b8e904e5..fabff602065f 100644
--- a/drivers/dma/xilinx/xilinx_dma.c
+++ b/drivers/dma/xilinx/xilinx_dma.c
@@ -41,11 +41,12 @@
 #include <linux/io.h>
 #include <linux/iopoll.h>
 #include <linux/module.h>
-#include <linux/of_address.h>
+#include <linux/of.h>
 #include <linux/of_dma.h>
-#include <linux/of_platform.h>
 #include <linux/of_irq.h>
+#include <linux/platform_device.h>
 #include <linux/slab.h>
+#include <linux/string_choices.h>
 #include <linux/clk.h>
 #include <linux/io-64-nonatomic-lo-hi.h>
 
@@ -112,7 +113,9 @@
 
 /* Register Direct Mode Registers */
 #define XILINX_DMA_REG_VSIZE			0x0000
+#define XILINX_DMA_VSIZE_MASK			GENMASK(12, 0)
 #define XILINX_DMA_REG_HSIZE			0x0004
+#define XILINX_DMA_HSIZE_MASK			GENMASK(15, 0)
 
 #define XILINX_DMA_REG_FRMDLY_STRIDE		0x0008
 #define XILINX_DMA_FRMDLY_STRIDE_FRMDLY_SHIFT	24
@@ -173,12 +176,15 @@
 #define XILINX_DMA_MAX_TRANS_LEN_MAX	23
 #define XILINX_DMA_V2_MAX_TRANS_LEN_MAX	26
 #define XILINX_DMA_CR_COALESCE_MAX	GENMASK(23, 16)
+#define XILINX_DMA_CR_DELAY_MAX		GENMASK(31, 24)
 #define XILINX_DMA_CR_CYCLIC_BD_EN_MASK	BIT(4)
 #define XILINX_DMA_CR_COALESCE_SHIFT	16
+#define XILINX_DMA_CR_DELAY_SHIFT	24
 #define XILINX_DMA_BD_SOP		BIT(27)
 #define XILINX_DMA_BD_EOP		BIT(26)
+#define XILINX_DMA_BD_COMP_MASK		BIT(31)
 #define XILINX_DMA_COALESCE_MAX		255
-#define XILINX_DMA_NUM_DESCS		255
+#define XILINX_DMA_NUM_DESCS		512
 #define XILINX_DMA_NUM_APP_WORDS	5
 
 /* AXI CDMA Specific Registers/Offsets */
@@ -394,6 +400,7 @@ struct xilinx_dma_tx_descriptor {
  * @genlock: Support genlock mode
  * @err: Channel has errors
  * @idle: Check for channel idle
+ * @terminating: Check for channel being synchronized by user
  * @tasklet: Cleanup work after irq
  * @config: Device configuration info
  * @flush_on_fsync: Flush on Frame sync
@@ -409,6 +416,7 @@ struct xilinx_dma_tx_descriptor {
  * @stop_transfer: Differentiate b/w DMA IP's quiesce
  * @tdest: TDEST value for mcdma
  * @has_vflip: S2MM vertical flip
+ * @irq_delay: Interrupt delay timeout
  */
 struct xilinx_dma_chan {
 	struct xilinx_dma_device *xdev;
@@ -431,6 +439,7 @@ struct xilinx_dma_chan {
 	bool genlock;
 	bool err;
 	bool idle;
+	bool terminating;
 	struct tasklet_struct tasklet;
 	struct xilinx_vdma_config config;
 	bool flush_on_fsync;
@@ -446,6 +455,7 @@ struct xilinx_dma_chan {
 	int (*stop_transfer)(struct xilinx_dma_chan *chan);
 	u16 tdest;
 	bool has_vflip;
+	u8 irq_delay;
 };
 
 /**
@@ -491,6 +501,7 @@ struct xilinx_dma_config {
  * @s2mm_chan_id: DMA s2mm channel identifier
  * @mm2s_chan_id: DMA mm2s channel identifier
  * @max_buffer_len: Max buffer length
+ * @has_axistream_connected: AXI DMA connected to AXI Stream IP
  */
 struct xilinx_dma_device {
 	void __iomem *regs;
@@ -509,6 +520,7 @@ struct xilinx_dma_device {
 	u32 s2mm_chan_id;
 	u32 mm2s_chan_id;
 	u32 max_buffer_len;
+	bool has_axistream_connected;
 };
 
 /* Macros */
@@ -621,6 +633,29 @@ static inline void xilinx_aximcdma_buf(struct xilinx_dma_chan *chan,
 	}
 }
 
+/**
+ * xilinx_dma_get_metadata_ptr- Populate metadata pointer and payload length
+ * @tx: async transaction descriptor
+ * @payload_len: metadata payload length
+ * @max_len: metadata max length
+ * Return: The app field pointer.
+ */
+static void *xilinx_dma_get_metadata_ptr(struct dma_async_tx_descriptor *tx,
+					 size_t *payload_len, size_t *max_len)
+{
+	struct xilinx_dma_tx_descriptor *desc = to_dma_tx_descriptor(tx);
+	struct xilinx_axidma_tx_segment *seg;
+
+	*max_len = *payload_len = sizeof(u32) * XILINX_DMA_NUM_APP_WORDS;
+	seg = list_first_entry(&desc->segments,
+			       struct xilinx_axidma_tx_segment, node);
+	return seg->hw.app;
+}
+
+static struct dma_descriptor_metadata_ops xilinx_dma_metadata_ops = {
+	.get_ptr = xilinx_dma_get_metadata_ptr,
+};
+
 /* -----------------------------------------------------------------------------
  * Descriptors and segments alloc and free
  */
@@ -790,7 +825,7 @@ static void xilinx_vdma_free_tx_segment(struct xilinx_dma_chan *chan,
 }
 
 /**
- * xilinx_dma_tx_descriptor - Allocate transaction descriptor
+ * xilinx_dma_alloc_tx_descriptor - Allocate transaction descriptor
  * @chan: Driver specific DMA channel
  *
  * Return: The allocated descriptor on success and NULL on failure.
@@ -996,14 +1031,12 @@ static void xilinx_dma_chan_handle_cyclic(struct xilinx_dma_chan *chan,
 					  struct xilinx_dma_tx_descriptor *desc,
 					  unsigned long *flags)
 {
-	dma_async_tx_callback callback;
-	void *callback_param;
+	struct dmaengine_desc_callback cb;
 
-	callback = desc->async_tx.callback;
-	callback_param = desc->async_tx.callback_param;
-	if (callback) {
+	dmaengine_desc_get_callback(&desc->async_tx, &cb);
+	if (dmaengine_desc_callback_valid(&cb)) {
 		spin_unlock_irqrestore(&chan->lock, *flags);
-		callback(callback_param);
+		dmaengine_desc_callback_invoke(&cb, NULL);
 		spin_lock_irqsave(&chan->lock, *flags);
 	}
 }
@@ -1049,6 +1082,13 @@ static void xilinx_dma_chan_desc_cleanup(struct xilinx_dma_chan *chan)
 		/* Run any dependencies, then free the descriptor */
 		dma_run_dependencies(&desc->async_tx);
 		xilinx_dma_free_tx_descriptor(chan, desc);
+
+		/*
+		 * While we ran a callback the user called a terminate function,
+		 * which takes care of cleaning up any remaining descriptors
+		 */
+		if (chan->terminating)
+			break;
 	}
 
 	spin_unlock_irqrestore(&chan->lock, flags);
@@ -1365,16 +1405,18 @@ static void xilinx_vdma_start_transfer(struct xilinx_dma_chan *chan)
 
 	dma_ctrl_write(chan, XILINX_DMA_REG_DMACR, reg);
 
-	j = chan->desc_submitcount;
-	reg = dma_read(chan, XILINX_DMA_REG_PARK_PTR);
-	if (chan->direction == DMA_MEM_TO_DEV) {
-		reg &= ~XILINX_DMA_PARK_PTR_RD_REF_MASK;
-		reg |= j << XILINX_DMA_PARK_PTR_RD_REF_SHIFT;
-	} else {
-		reg &= ~XILINX_DMA_PARK_PTR_WR_REF_MASK;
-		reg |= j << XILINX_DMA_PARK_PTR_WR_REF_SHIFT;
+	if (config->park) {
+		j = chan->desc_submitcount;
+		reg = dma_read(chan, XILINX_DMA_REG_PARK_PTR);
+		if (chan->direction == DMA_MEM_TO_DEV) {
+			reg &= ~XILINX_DMA_PARK_PTR_RD_REF_MASK;
+			reg |= j << XILINX_DMA_PARK_PTR_RD_REF_SHIFT;
+		} else {
+			reg &= ~XILINX_DMA_PARK_PTR_WR_REF_MASK;
+			reg |= j << XILINX_DMA_PARK_PTR_WR_REF_SHIFT;
+		}
+		dma_write(chan, XILINX_DMA_REG_PARK_PTR, reg);
 	}
-	dma_write(chan, XILINX_DMA_REG_PARK_PTR, reg);
 
 	/* Start the hardware */
 	xilinx_dma_start(chan);
@@ -1411,8 +1453,7 @@ static void xilinx_vdma_start_transfer(struct xilinx_dma_chan *chan)
 
 	chan->desc_submitcount++;
 	chan->desc_pendingcount--;
-	list_del(&desc->node);
-	list_add_tail(&desc->node, &chan->active_list);
+	list_move_tail(&desc->node, &chan->active_list);
 	if (chan->desc_submitcount == chan->num_frms)
 		chan->desc_submitcount = 0;
 
@@ -1529,6 +1570,9 @@ static void xilinx_dma_start_transfer(struct xilinx_dma_chan *chan)
 	if (chan->has_sg)
 		xilinx_write(chan, XILINX_DMA_REG_CURDESC,
 			     head_desc->async_tx.phys);
+	reg  &= ~XILINX_DMA_CR_DELAY_MAX;
+	reg  |= chan->irq_delay << XILINX_DMA_CR_DELAY_SHIFT;
+	dma_ctrl_write(chan, XILINX_DMA_REG_DMACR, reg);
 
 	xilinx_dma_start(chan);
 
@@ -1650,6 +1694,19 @@ static void xilinx_dma_issue_pending(struct dma_chan *dchan)
 }
 
 /**
+ * xilinx_dma_device_config - Configure the DMA channel
+ * @dchan: DMA channel
+ * @config: channel configuration
+ *
+ * Return: 0 always.
+ */
+static int xilinx_dma_device_config(struct dma_chan *dchan,
+				    struct dma_slave_config *config)
+{
+	return 0;
+}
+
+/**
  * xilinx_dma_complete_descriptor - Mark the active descriptor as complete
  * @chan : xilinx DMA channel
  *
@@ -1664,6 +1721,14 @@ static void xilinx_dma_complete_descriptor(struct xilinx_dma_chan *chan)
 		return;
 
 	list_for_each_entry_safe(desc, next, &chan->active_list, node) {
+		if (chan->xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA) {
+			struct xilinx_axidma_tx_segment *seg;
+
+			seg = list_last_entry(&desc->segments,
+					      struct xilinx_axidma_tx_segment, node);
+			if (!(seg->hw.status & XILINX_DMA_BD_COMP_MASK) && chan->has_sg)
+				break;
+		}
 		if (chan->has_sg && chan->xdev->dma_config->dmatype !=
 		    XDMA_TYPE_VDMA)
 			desc->residue = xilinx_dma_get_residue(chan, desc);
@@ -1797,7 +1862,7 @@ static irqreturn_t xilinx_mcdma_irq_handler(int irq, void *data)
 		spin_unlock(&chan->lock);
 	}
 
-	tasklet_schedule(&chan->tasklet);
+	tasklet_hi_schedule(&chan->tasklet);
 	return IRQ_HANDLED;
 }
 
@@ -1845,15 +1910,8 @@ static irqreturn_t xilinx_dma_irq_handler(int irq, void *data)
 		}
 	}
 
-	if (status & XILINX_DMA_DMASR_DLY_CNT_IRQ) {
-		/*
-		 * Device takes too long to do the transfer when user requires
-		 * responsiveness.
-		 */
-		dev_dbg(chan->dev, "Inter-packet latency too long\n");
-	}
-
-	if (status & XILINX_DMA_DMASR_FRM_CNT_IRQ) {
+	if (status & (XILINX_DMA_DMASR_FRM_CNT_IRQ |
+		      XILINX_DMA_DMASR_DLY_CNT_IRQ)) {
 		spin_lock(&chan->lock);
 		xilinx_dma_complete_descriptor(chan);
 		chan->idle = true;
@@ -1965,6 +2023,8 @@ static dma_cookie_t xilinx_dma_tx_submit(struct dma_async_tx_descriptor *tx)
 	if (desc->cyclic)
 		chan->cyclic = true;
 
+	chan->terminating = false;
+
 	spin_unlock_irqrestore(&chan->lock, flags);
 
 	return cookie;
@@ -1995,6 +2055,10 @@ xilinx_vdma_dma_prep_interleaved(struct dma_chan *dchan,
 	if (!xt->numf || !xt->sgl[0].size)
 		return NULL;
 
+	if (xt->numf & ~XILINX_DMA_VSIZE_MASK ||
+	    xt->sgl[0].size & ~XILINX_DMA_HSIZE_MASK)
+		return NULL;
+
 	if (xt->frame_size != 1)
 		return NULL;
 
@@ -2109,6 +2173,99 @@ error:
 }
 
 /**
+ * xilinx_dma_prep_peripheral_dma_vec - prepare descriptors for a DMA_SLAVE
+ *	transaction from DMA vectors
+ * @dchan: DMA channel
+ * @vecs: Array of DMA vectors that should be transferred
+ * @nb: number of entries in @vecs
+ * @direction: DMA direction
+ * @flags: transfer ack flags
+ *
+ * Return: Async transaction descriptor on success and NULL on failure
+ */
+static struct dma_async_tx_descriptor *xilinx_dma_prep_peripheral_dma_vec(
+	struct dma_chan *dchan, const struct dma_vec *vecs, size_t nb,
+	enum dma_transfer_direction direction, unsigned long flags)
+{
+	struct xilinx_dma_chan *chan = to_xilinx_chan(dchan);
+	struct xilinx_dma_tx_descriptor *desc;
+	struct xilinx_axidma_tx_segment *segment, *head, *prev = NULL;
+	size_t copy;
+	size_t sg_used;
+	unsigned int i;
+
+	if (!is_slave_direction(direction) || direction != chan->direction)
+		return NULL;
+
+	desc = xilinx_dma_alloc_tx_descriptor(chan);
+	if (!desc)
+		return NULL;
+
+	dma_async_tx_descriptor_init(&desc->async_tx, &chan->common);
+	desc->async_tx.tx_submit = xilinx_dma_tx_submit;
+
+	/* Build transactions using information from DMA vectors */
+	for (i = 0; i < nb; i++) {
+		sg_used = 0;
+
+		/* Loop until the entire dma_vec entry is used */
+		while (sg_used < vecs[i].len) {
+			struct xilinx_axidma_desc_hw *hw;
+
+			/* Get a free segment */
+			segment = xilinx_axidma_alloc_tx_segment(chan);
+			if (!segment)
+				goto error;
+
+			/*
+			 * Calculate the maximum number of bytes to transfer,
+			 * making sure it is less than the hw limit
+			 */
+			copy = xilinx_dma_calc_copysize(chan, vecs[i].len,
+					sg_used);
+			hw = &segment->hw;
+
+			/* Fill in the descriptor */
+			xilinx_axidma_buf(chan, hw, vecs[i].addr, sg_used, 0);
+			hw->control = copy;
+
+			if (prev)
+				prev->hw.next_desc = segment->phys;
+
+			prev = segment;
+			sg_used += copy;
+
+			/*
+			 * Insert the segment into the descriptor segments
+			 * list.
+			 */
+			list_add_tail(&segment->node, &desc->segments);
+		}
+	}
+
+	head = list_first_entry(&desc->segments, struct xilinx_axidma_tx_segment, node);
+	desc->async_tx.phys = head->phys;
+
+	/* For the last DMA_MEM_TO_DEV transfer, set EOP */
+	if (chan->direction == DMA_MEM_TO_DEV) {
+		segment->hw.control |= XILINX_DMA_BD_SOP;
+		segment = list_last_entry(&desc->segments,
+					  struct xilinx_axidma_tx_segment,
+					  node);
+		segment->hw.control |= XILINX_DMA_BD_EOP;
+	}
+
+	if (chan->xdev->has_axistream_connected)
+		desc->async_tx.metadata_ops = &xilinx_dma_metadata_ops;
+
+	return &desc->async_tx;
+
+error:
+	xilinx_dma_free_tx_descriptor(chan, desc);
+	return NULL;
+}
+
+/**
  * xilinx_dma_prep_slave_sg - prepare descriptors for a DMA_SLAVE transaction
  * @dchan: DMA channel
  * @sgl: scatterlist to transfer to/from
@@ -2200,6 +2357,9 @@ static struct dma_async_tx_descriptor *xilinx_dma_prep_slave_sg(
 		segment->hw.control |= XILINX_DMA_BD_EOP;
 	}
 
+	if (chan->xdev->has_axistream_connected)
+		desc->async_tx.metadata_ops = &xilinx_dma_metadata_ops;
+
 	return &desc->async_tx;
 
 error:
@@ -2436,6 +2596,7 @@ static int xilinx_dma_terminate_all(struct dma_chan *dchan)
 
 	xilinx_dma_chan_reset(chan);
 	/* Remove and free all of the descriptors in the lists */
+	chan->terminating = true;
 	xilinx_dma_free_descriptors(chan);
 	chan->idle = true;
 
@@ -2461,7 +2622,7 @@ static void xilinx_dma_synchronize(struct dma_chan *dchan)
 }
 
 /**
- * xilinx_dma_channel_set_config - Configure VDMA channel
+ * xilinx_vdma_channel_set_config - Configure VDMA channel
  * Run-time configuration for Axi VDMA, supports:
  * . halt the channel
  * . configure interrupt coalescing and inter-packet delay threshold
@@ -2774,6 +2935,8 @@ static int xilinx_dma_chan_probe(struct xilinx_dma_device *xdev,
 	/* Retrieve the channel properties from the device tree */
 	has_dre = of_property_read_bool(node, "xlnx,include-dre");
 
+	of_property_read_u8(node, "xlnx,irq-delay", &chan->irq_delay);
+
 	chan->genlock = of_property_read_bool(node, "xlnx,genlock-mode");
 
 	err = of_property_read_u32(node, "xlnx,datawidth", &value);
@@ -2839,8 +3002,12 @@ static int xilinx_dma_chan_probe(struct xilinx_dma_device *xdev,
 		return -EINVAL;
 	}
 
+	xdev->common.directions |= chan->direction;
+
 	/* Request the interrupt */
-	chan->irq = irq_of_parse_and_map(node, chan->tdest);
+	chan->irq = of_irq_get(node, chan->tdest);
+	if (chan->irq < 0)
+		return dev_err_probe(xdev->dev, chan->irq, "failed to get irq\n");
 	err = request_irq(chan->irq, xdev->dma_config->irq_handler,
 			  IRQF_SHARED, "xilinx-dma-controller", chan);
 	if (err) {
@@ -2869,7 +3036,7 @@ static int xilinx_dma_chan_probe(struct xilinx_dma_device *xdev,
 			    XILINX_DMA_DMASR_SG_MASK)
 			chan->has_sg = true;
 		dev_dbg(chan->dev, "ch %d: SG %s\n", chan->id,
-			chan->has_sg ? "enabled" : "disabled");
+			str_enabled_disabled(chan->has_sg));
 	}
 
 	/* Initialize the tasklet */
@@ -2902,7 +3069,7 @@ static int xilinx_dma_chan_probe(struct xilinx_dma_device *xdev,
  * @xdev: Driver specific device structure
  * @node: Device node
  *
- * Return: 0 always.
+ * Return: '0' on success and failure value on error.
  */
 static int xilinx_dma_child_probe(struct xilinx_dma_device *xdev,
 				    struct device_node *node)
@@ -2914,8 +3081,11 @@ static int xilinx_dma_child_probe(struct xilinx_dma_device *xdev,
 	if (xdev->dma_config->dmatype == XDMA_TYPE_AXIMCDMA && ret < 0)
 		dev_warn(xdev->dev, "missing dma-channels property\n");
 
-	for (i = 0; i < nr_channels; i++)
-		xilinx_dma_chan_probe(xdev, node);
+	for (i = 0; i < nr_channels; i++) {
+		ret = xilinx_dma_chan_probe(xdev, node);
+		if (ret)
+			return ret;
+	}
 
 	return 0;
 }
@@ -3015,9 +3185,10 @@ static int xilinx_dma_probe(struct platform_device *pdev)
 
 	/* Request and map I/O memory */
 	xdev->regs = devm_platform_ioremap_resource(pdev, 0);
-	if (IS_ERR(xdev->regs))
-		return PTR_ERR(xdev->regs);
-
+	if (IS_ERR(xdev->regs)) {
+		err = PTR_ERR(xdev->regs);
+		goto disable_clks;
+	}
 	/* Retrieve the DMA engine properties from the device tree */
 	xdev->max_buffer_len = GENMASK(XILINX_DMA_MAX_TRANS_LEN_MAX - 1, 0);
 	xdev->s2mm_chan_id = xdev->dma_config->max_channels / 2;
@@ -3039,13 +3210,20 @@ static int xilinx_dma_probe(struct platform_device *pdev)
 		}
 	}
 
+	dma_set_max_seg_size(xdev->dev, xdev->max_buffer_len);
+
+	if (xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA) {
+		xdev->has_axistream_connected =
+			of_property_read_bool(node, "xlnx,axistream-connected");
+	}
+
 	if (xdev->dma_config->dmatype == XDMA_TYPE_VDMA) {
 		err = of_property_read_u32(node, "xlnx,num-fstores",
 					   &num_frames);
 		if (err < 0) {
 			dev_err(xdev->dev,
 				"missing xlnx,num-fstores property\n");
-			return err;
+			goto disable_clks;
 		}
 
 		err = of_property_read_u32(node, "xlnx,flush-fsync",
@@ -3064,8 +3242,16 @@ static int xilinx_dma_probe(struct platform_device *pdev)
 	else
 		xdev->ext_addr = false;
 
+	/* Set metadata mode */
+	if (xdev->has_axistream_connected)
+		xdev->common.desc_metadata_modes = DESC_METADATA_ENGINE;
+
 	/* Set the dma mask bits */
-	dma_set_mask(xdev->dev, DMA_BIT_MASK(addr_width));
+	err = dma_set_mask_and_coherent(xdev->dev, DMA_BIT_MASK(addr_width));
+	if (err < 0) {
+		dev_err(xdev->dev, "DMA mask error %d\n", err);
+		goto disable_clks;
+	}
 
 	/* Initialize the DMA engine */
 	xdev->common.dev = &pdev->dev;
@@ -3084,8 +3270,10 @@ static int xilinx_dma_probe(struct platform_device *pdev)
 	xdev->common.device_synchronize = xilinx_dma_synchronize;
 	xdev->common.device_tx_status = xilinx_dma_tx_status;
 	xdev->common.device_issue_pending = xilinx_dma_issue_pending;
+	xdev->common.device_config = xilinx_dma_device_config;
 	if (xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA) {
 		dma_cap_set(DMA_CYCLIC, xdev->common.cap_mask);
+		xdev->common.device_prep_peripheral_dma_vec = xilinx_dma_prep_peripheral_dma_vec;
 		xdev->common.device_prep_slave_sg = xilinx_dma_prep_slave_sg;
 		xdev->common.device_prep_dma_cyclic =
 					  xilinx_dma_prep_dma_cyclic;
@@ -3110,8 +3298,10 @@ static int xilinx_dma_probe(struct platform_device *pdev)
 	/* Initialize the channels */
 	for_each_child_of_node(node, child) {
 		err = xilinx_dma_child_probe(xdev, child);
-		if (err < 0)
-			goto disable_clks;
+		if (err < 0) {
+			of_node_put(child);
+			goto error;
+		}
 	}
 
 	if (xdev->dma_config->dmatype == XDMA_TYPE_VDMA) {
@@ -3146,12 +3336,12 @@ static int xilinx_dma_probe(struct platform_device *pdev)
 
 	return 0;
 
-disable_clks:
-	xdma_disable_allclks(xdev);
 error:
 	for (i = 0; i < xdev->dma_config->max_channels; i++)
 		if (xdev->chan[i])
 			xilinx_dma_chan_remove(xdev->chan[i]);
+disable_clks:
+	xdma_disable_allclks(xdev);
 
 	return err;
 }
@@ -3159,10 +3349,8 @@ error:
 /**
  * xilinx_dma_remove - Driver remove function
  * @pdev: Pointer to the platform_device structure
- *
- * Return: Always '0'
  */
-static int xilinx_dma_remove(struct platform_device *pdev)
+static void xilinx_dma_remove(struct platform_device *pdev)
 {
 	struct xilinx_dma_device *xdev = platform_get_drvdata(pdev);
 	int i;
@@ -3176,8 +3364,6 @@ static int xilinx_dma_remove(struct platform_device *pdev)
 			xilinx_dma_chan_remove(xdev->chan[i]);
 
 	xdma_disable_allclks(xdev);
-
-	return 0;
 }
 
 static struct platform_driver xilinx_vdma_driver = {