dmaengine: qcom_hidma: introduce memset support

HIDMA HW supports memset operation in addition to memcpy.
Since the memset API is present on the kernel now, bring the
memset feature into life.

The descriptor format is the same for both memcpy and memset.
Type of the descriptor is 4 when memset is requested.
The lowest 8 bits of the source DMA argument is used as a
fill pattern.

Signed-off-by: Sinan Kaya <[e-mail]>
Signed-off-by: Vinod Koul <[e-mail]>

drivers/dma/qcom/hidma.c

···
 		return NULL;
 
 	hidma_ll_set_transfer_params(mdma->lldev, mdesc->tre_ch,
-				     src, dest, len, flags);
+				     src, dest, len, flags,
+				     HIDMA_TRE_MEMCPY);
+
+	/* Place descriptor in prepared list */
+	spin_lock_irqsave(&mchan->lock, irqflags);
+	list_add_tail(&mdesc->node, &mchan->prepared);
+	spin_unlock_irqrestore(&mchan->lock, irqflags);
+
+	return &mdesc->desc;
+}
+
+static struct dma_async_tx_descriptor *
+hidma_prep_dma_memset(struct dma_chan *dmach, dma_addr_t dest, int value,
+		size_t len, unsigned long flags)
+{
+	struct hidma_chan *mchan = to_hidma_chan(dmach);
+	struct hidma_desc *mdesc = NULL;
+	struct hidma_dev *mdma = mchan->dmadev;
+	unsigned long irqflags;
+
+	/* Get free descriptor */
+	spin_lock_irqsave(&mchan->lock, irqflags);
+	if (!list_empty(&mchan->free)) {
+		mdesc = list_first_entry(&mchan->free, struct hidma_desc, node);
+		list_del(&mdesc->node);
+	}
+	spin_unlock_irqrestore(&mchan->lock, irqflags);
+
+	if (!mdesc)
+		return NULL;
+
+	hidma_ll_set_transfer_params(mdma->lldev, mdesc->tre_ch,
+				     value, dest, len, flags,
+				     HIDMA_TRE_MEMSET);
 
 	/* Place descriptor in prepared list */
 	spin_lock_irqsave(&mchan->lock, irqflags);
···
 	pm_runtime_get_sync(dmadev->ddev.dev);
 
 	dma_cap_set(DMA_MEMCPY, dmadev->ddev.cap_mask);
+	dma_cap_set(DMA_MEMSET, dmadev->ddev.cap_mask);
 	if (WARN_ON(!pdev->dev.dma_mask)) {
 		rc = -ENXIO;
 		goto dmafree;
···
 	dmadev->dev_trca = trca;
 	dmadev->trca_resource = trca_resource;
 	dmadev->ddev.device_prep_dma_memcpy = hidma_prep_dma_memcpy;
+	dmadev->ddev.device_prep_dma_memset = hidma_prep_dma_memset;
 	dmadev->ddev.device_alloc_chan_resources = hidma_alloc_chan_resources;
 	dmadev->ddev.device_free_chan_resources = hidma_free_chan_resources;
 	dmadev->ddev.device_tx_status = hidma_tx_status;

drivers/dma/qcom/hidma.h

···
 #define HIDMA_TRE_DEST_LOW_IDX		4
 #define HIDMA_TRE_DEST_HI_IDX		5
 
+enum tre_type {
+	HIDMA_TRE_MEMCPY = 3,
+	HIDMA_TRE_MEMSET = 4,
+};
+
 struct hidma_tre {
 	atomic_t allocated;		/* if this channel is allocated	    */
 	bool queued;			/* flag whether this is pending     */
···
 int hidma_ll_disable(struct hidma_lldev *lldev);
 int hidma_ll_enable(struct hidma_lldev *llhndl);
 void hidma_ll_set_transfer_params(struct hidma_lldev *llhndl, u32 tre_ch,
-	dma_addr_t src, dma_addr_t dest, u32 len, u32 flags);
+	dma_addr_t src, dma_addr_t dest, u32 len, u32 flags, u32 txntype);
 void hidma_ll_setup_irq(struct hidma_lldev *lldev, bool msi);
 int hidma_ll_setup(struct hidma_lldev *lldev);
 struct hidma_lldev *hidma_ll_init(struct device *dev, u32 max_channels,

drivers/dma/qcom/hidma_ll.c

···
 	HIDMA_CH_STOPPED = 4,
 };
 
-enum tre_type {
-	HIDMA_TRE_MEMCPY = 3,
-};
-
 enum err_code {
 	HIDMA_EVRE_STATUS_COMPLETE = 1,
 	HIDMA_EVRE_STATUS_ERROR = 4,
···
 	tre->err_info = 0;
 	tre->lldev = lldev;
 	tre_local = &tre->tre_local[0];
-	tre_local[HIDMA_TRE_CFG_IDX] = HIDMA_TRE_MEMCPY;
-	tre_local[HIDMA_TRE_CFG_IDX] |= (lldev->chidx & 0xFF) << 8;
+	tre_local[HIDMA_TRE_CFG_IDX] = (lldev->chidx & 0xFF) << 8;
 	tre_local[HIDMA_TRE_CFG_IDX] |= BIT(16);	/* set IEOB */
 	*tre_ch = i;
 	if (callback)
···
 
 void hidma_ll_set_transfer_params(struct hidma_lldev *lldev, u32 tre_ch,
 				  dma_addr_t src, dma_addr_t dest, u32 len,
-				  u32 flags)
+				  u32 flags, u32 txntype)
 {
 	struct hidma_tre *tre;
 	u32 *tre_local;
···
 	}
 
 	tre_local = &tre->tre_local[0];
+	tre_local[HIDMA_TRE_CFG_IDX] &= ~GENMASK(7, 0);
+	tre_local[HIDMA_TRE_CFG_IDX] |= txntype;
 	tre_local[HIDMA_TRE_LEN_IDX] = len;
 	tre_local[HIDMA_TRE_SRC_LOW_IDX] = lower_32_bits(src);
 	tre_local[HIDMA_TRE_SRC_HI_IDX] = upper_32_bits(src);