dmaengine: fsl-edma: support edma memcpy

Add memcpy in edma. The edma has the capability to transfer data by
software trigger so that it could be used for memory copy. Enable
MEMCPY for edma driver and it could be test directly by dmatest.

Signed-off-by: Joy Zou <joy.zou@nxp.com>
Link: https://lore.kernel.org/r/20211026090025.2777292-1-joy.zou@nxp.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/fsl-edma-common.c

@@ -348,6 +348,7 @@ static void fsl_edma_set_tcd_regs(struct fsl_edma_chan *fsl_chan,
 	struct fsl_edma_engine *edma = fsl_chan->edma;
 	struct edma_regs *regs = &fsl_chan->edma->regs;
 	u32 ch = fsl_chan->vchan.chan.chan_id;
+	u16 csr = 0;
 
 	/*
 	 * TCD parameters are stored in struct fsl_edma_hw_tcd in little
@@ -373,6 +374,12 @@ static void fsl_edma_set_tcd_regs(struct fsl_edma_chan *fsl_chan,
 	edma_writel(edma, (s32)tcd->dlast_sga,
 			&regs->tcd[ch].dlast_sga);
 
+	if (fsl_chan->is_sw) {
+		csr = le16_to_cpu(tcd->csr);
+		csr |= EDMA_TCD_CSR_START;
+		tcd->csr = cpu_to_le16(csr);
+	}
+
 	edma_writew(edma, (s16)tcd->csr, &regs->tcd[ch].csr);
 }
 
@@ -587,6 +594,29 @@ struct dma_async_tx_descriptor *fsl_edma_prep_slave_sg(
 }
 EXPORT_SYMBOL_GPL(fsl_edma_prep_slave_sg);
 
+struct dma_async_tx_descriptor *fsl_edma_prep_memcpy(struct dma_chan *chan,
+						     dma_addr_t dma_dst, dma_addr_t dma_src,
+						     size_t len, unsigned long flags)
+{
+	struct fsl_edma_chan *fsl_chan = to_fsl_edma_chan(chan);
+	struct fsl_edma_desc *fsl_desc;
+
+	fsl_desc = fsl_edma_alloc_desc(fsl_chan, 1);
+	if (!fsl_desc)
+		return NULL;
+	fsl_desc->iscyclic = false;
+
+	fsl_chan->is_sw = true;
+
+	/* To match with copy_align and max_seg_size so 1 tcd is enough */
+	fsl_edma_fill_tcd(fsl_desc->tcd[0].vtcd, dma_src, dma_dst,
+			EDMA_TCD_ATTR_SSIZE_32BYTE | EDMA_TCD_ATTR_DSIZE_32BYTE,
+			32, len, 0, 1, 1, 32, 0, true, true, false);
+
+	return vchan_tx_prep(&fsl_chan->vchan, &fsl_desc->vdesc, flags);
+}
+EXPORT_SYMBOL_GPL(fsl_edma_prep_memcpy);
+
 void fsl_edma_xfer_desc(struct fsl_edma_chan *fsl_chan)
 {
 	struct virt_dma_desc *vdesc;
@@ -654,6 +684,7 @@ void fsl_edma_free_chan_resources(struct dma_chan *chan)
 	vchan_dma_desc_free_list(&fsl_chan->vchan, &head);
 	dma_pool_destroy(fsl_chan->tcd_pool);
 	fsl_chan->tcd_pool = NULL;
+	fsl_chan->is_sw = false;
 }
 EXPORT_SYMBOL_GPL(fsl_edma_free_chan_resources);
 

drivers/dma/fsl-edma-common.h

@@ -121,6 +121,7 @@ struct fsl_edma_chan {
 	struct fsl_edma_desc		*edesc;
 	struct dma_slave_config		cfg;
 	u32				attr;
+	bool                            is_sw;
 	struct dma_pool			*tcd_pool;
 	dma_addr_t			dma_dev_addr;
 	u32				dma_dev_size;
@@ -240,6 +241,9 @@ struct dma_async_tx_descriptor *fsl_edma_prep_slave_sg(
 		struct dma_chan *chan, struct scatterlist *sgl,
 		unsigned int sg_len, enum dma_transfer_direction direction,
 		unsigned long flags, void *context);
+struct dma_async_tx_descriptor *fsl_edma_prep_memcpy(
+		struct dma_chan *chan, dma_addr_t dma_dst, dma_addr_t dma_src,
+		size_t len, unsigned long flags);
 void fsl_edma_xfer_desc(struct fsl_edma_chan *fsl_chan);
 void fsl_edma_issue_pending(struct dma_chan *chan);
 int fsl_edma_alloc_chan_resources(struct dma_chan *chan);

drivers/dma/fsl-edma.c

@@ -17,6 +17,7 @@
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
 #include <linux/of_dma.h>
+#include <linux/dma-mapping.h>
 
 #include "fsl-edma-common.h"
 
@@ -372,6 +373,7 @@ static int fsl_edma_probe(struct platform_device *pdev)
 	dma_cap_set(DMA_PRIVATE, fsl_edma->dma_dev.cap_mask);
 	dma_cap_set(DMA_SLAVE, fsl_edma->dma_dev.cap_mask);
 	dma_cap_set(DMA_CYCLIC, fsl_edma->dma_dev.cap_mask);
+	dma_cap_set(DMA_MEMCPY, fsl_edma->dma_dev.cap_mask);
 
 	fsl_edma->dma_dev.dev = &pdev->dev;
 	fsl_edma->dma_dev.device_alloc_chan_resources
@@ -381,6 +383,7 @@ static int fsl_edma_probe(struct platform_device *pdev)
 	fsl_edma->dma_dev.device_tx_status = fsl_edma_tx_status;
 	fsl_edma->dma_dev.device_prep_slave_sg = fsl_edma_prep_slave_sg;
 	fsl_edma->dma_dev.device_prep_dma_cyclic = fsl_edma_prep_dma_cyclic;
+	fsl_edma->dma_dev.device_prep_dma_memcpy = fsl_edma_prep_memcpy;
 	fsl_edma->dma_dev.device_config = fsl_edma_slave_config;
 	fsl_edma->dma_dev.device_pause = fsl_edma_pause;
 	fsl_edma->dma_dev.device_resume = fsl_edma_resume;
@@ -392,6 +395,10 @@ static int fsl_edma_probe(struct platform_device *pdev)
 	fsl_edma->dma_dev.dst_addr_widths = FSL_EDMA_BUSWIDTHS;
 	fsl_edma->dma_dev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
 
+	fsl_edma->dma_dev.copy_align = DMAENGINE_ALIGN_32_BYTES;
+	/* Per worst case 'nbytes = 1' take CITER as the max_seg_size */
+	dma_set_max_seg_size(fsl_edma->dma_dev.dev, 0x3fff);
+
 	platform_set_drvdata(pdev, fsl_edma);
 
 	ret = dma_async_device_register(&fsl_edma->dma_dev);