mtd: nand: sunxi: add support for DMA operations

index a71905c..f6ea0fb 100644
@@ -776,6 +776,92 @@ static inline void sunxi_nfc_user_data_to_buf(u32 user_data, u8 *buf)
 	buf[3] = user_data >> 24;
 }
 
+static inline u32 sunxi_nfc_buf_to_user_data(const u8 *buf)
+{
+	return buf[0] | (buf[1] << 8) | (buf[2] << 16) | (buf[3] << 24);
+}
+
+static void sunxi_nfc_hw_ecc_get_prot_oob_bytes(struct mtd_info *mtd, u8 *oob,
+						int step, bool bbm, int page)
+{
+	struct nand_chip *nand = mtd_to_nand(mtd);
+	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
+
+	sunxi_nfc_user_data_to_buf(readl(nfc->regs + NFC_REG_USER_DATA(step)),
+				   oob);
+
+	/* De-randomize the Bad Block Marker. */
+	if (bbm && (nand->options & NAND_NEED_SCRAMBLING))
+		sunxi_nfc_randomize_bbm(mtd, page, oob);
+}
+
+static void sunxi_nfc_hw_ecc_set_prot_oob_bytes(struct mtd_info *mtd,
+						const u8 *oob, int step,
+						bool bbm, int page)
+{
+	struct nand_chip *nand = mtd_to_nand(mtd);
+	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
+	u8 user_data[4];
+
+	/* Randomize the Bad Block Marker. */
+	if (bbm && (nand->options & NAND_NEED_SCRAMBLING)) {
+		memcpy(user_data, oob, sizeof(user_data));
+		sunxi_nfc_randomize_bbm(mtd, page, user_data);
+		oob = user_data;
+	}
+
+	writel(sunxi_nfc_buf_to_user_data(oob),
+	       nfc->regs + NFC_REG_USER_DATA(step));
+}
+
+static void sunxi_nfc_hw_ecc_update_stats(struct mtd_info *mtd,
+					  unsigned int *max_bitflips, int ret)
+{
+	if (ret < 0) {
+		mtd->ecc_stats.failed++;
+	} else {
+		mtd->ecc_stats.corrected += ret;
+		*max_bitflips = max_t(unsigned int, *max_bitflips, ret);
+	}
+}
+
+static int sunxi_nfc_hw_ecc_correct(struct mtd_info *mtd, u8 *data, u8 *oob,
+				    int step, u32 status, bool *erased)
+{
+	struct nand_chip *nand = mtd_to_nand(mtd);
+	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
+	struct nand_ecc_ctrl *ecc = &nand->ecc;
+	u32 tmp;
+
+	*erased = false;
+
+	if (status & NFC_ECC_ERR(step))
+		return -EBADMSG;
+
+	if (status & NFC_ECC_PAT_FOUND(step)) {
+		u8 pattern;
+
+		if (unlikely(!(readl(nfc->regs + NFC_REG_PAT_ID) & 0x1))) {
+			pattern = 0x0;
+		} else {
+			pattern = 0xff;
+			*erased = true;
+		}
+
+		if (data)
+			memset(data, pattern, ecc->size);
+
+		if (oob)
+			memset(oob, pattern, ecc->bytes + 4);
+
+		return 0;
+	}
+
+	tmp = readl(nfc->regs + NFC_REG_ECC_ERR_CNT(step));
+
+	return NFC_ECC_ERR_CNT(step, tmp);
+}
+
 static int sunxi_nfc_hw_ecc_read_chunk(struct mtd_info *mtd,
 				       u8 *data, int data_off,
 				       u8 *oob, int oob_off,

@@ -787,7 +873,7 @@ static int sunxi_nfc_hw_ecc_read_chunk(struct mtd_info *mtd,
 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
 	struct nand_ecc_ctrl *ecc = &nand->ecc;
 	int raw_mode = 0;
-	u32 status;
+	bool erased;
 	int ret;
 
 	if (*cur_off != data_off)

@@ -813,27 +899,13 @@ static int sunxi_nfc_hw_ecc_read_chunk(struct mtd_info *mtd,
 
 	*cur_off = oob_off + ecc->bytes + 4;
 
-	status = readl(nfc->regs + NFC_REG_ECC_ST);
-	if (status & NFC_ECC_PAT_FOUND(0)) {
-		u8 pattern = 0xff;
-
-		if (unlikely(!(readl(nfc->regs + NFC_REG_PAT_ID) & 0x1)))
-			pattern = 0x0;
-
-		memset(data, pattern, ecc->size);
-		memset(oob, pattern, ecc->bytes + 4);
-
+	ret = sunxi_nfc_hw_ecc_correct(mtd, data, oob, 0,
+				       readl(nfc->regs + NFC_REG_ECC_ST),
+				       &erased);
+	if (erased)
 		return 1;
-	}
-
-	ret = NFC_ECC_ERR_CNT(0, readl(nfc->regs + NFC_REG_ECC_ERR_CNT(0)));
-
-	memcpy_fromio(data, nfc->regs + NFC_RAM0_BASE, ecc->size);
 
-	nand->cmdfunc(mtd, NAND_CMD_RNDOUT, oob_off, -1);
-	sunxi_nfc_randomizer_read_buf(mtd, oob, ecc->bytes + 4, true, page);
-
-	if (status & NFC_ECC_ERR(0)) {
+	if (ret < 0) {
 		/*
 		 * Re-read the data with the randomizer disabled to identify
 		 * bitflips in erased pages.

@@ -841,35 +913,32 @@ static int sunxi_nfc_hw_ecc_read_chunk(struct mtd_info *mtd,
 		if (nand->options & NAND_NEED_SCRAMBLING) {
 			nand->cmdfunc(mtd, NAND_CMD_RNDOUT, data_off, -1);
 			nand->read_buf(mtd, data, ecc->size);
-			nand->cmdfunc(mtd, NAND_CMD_RNDOUT, oob_off, -1);
-			nand->read_buf(mtd, oob, ecc->bytes + 4);
+		} else {
+			memcpy_fromio(data, nfc->regs + NFC_RAM0_BASE,
+				      ecc->size);
 		}
 
+		nand->cmdfunc(mtd, NAND_CMD_RNDOUT, oob_off, -1);
+		nand->read_buf(mtd, oob, ecc->bytes + 4);
+
 		ret = nand_check_erased_ecc_chunk(data,	ecc->size,
 						  oob, ecc->bytes + 4,
 						  NULL, 0, ecc->strength);
 		if (ret >= 0)
 			raw_mode = 1;
 	} else {
-		/*
-		 * The engine protects 4 bytes of OOB data per chunk.
-		 * Retrieve the corrected OOB bytes.
-		 */
-		sunxi_nfc_user_data_to_buf(readl(nfc->regs + NFC_REG_USER_DATA(0)),
-					   oob);
+		memcpy_fromio(data, nfc->regs + NFC_RAM0_BASE, ecc->size);
 
-		/* De-randomize the Bad Block Marker. */
-		if (bbm && nand->options & NAND_NEED_SCRAMBLING)
-			sunxi_nfc_randomize_bbm(mtd, page, oob);
-	}
+		nand->cmdfunc(mtd, NAND_CMD_RNDOUT, oob_off, -1);
+		sunxi_nfc_randomizer_read_buf(mtd, oob, ecc->bytes + 4,
+					      true, page);
 
-	if (ret < 0) {
-		mtd->ecc_stats.failed++;
-	} else {
-		mtd->ecc_stats.corrected += ret;
-		*max_bitflips = max_t(unsigned int, *max_bitflips, ret);
+		sunxi_nfc_hw_ecc_get_prot_oob_bytes(mtd, oob, 0,
+						    bbm, page);
 	}
 
+	sunxi_nfc_hw_ecc_update_stats(mtd, max_bitflips, ret);
+
 	return raw_mode;
 }
 

@@ -898,11 +967,6 @@ static void sunxi_nfc_hw_ecc_read_extra_oob(struct mtd_info *mtd,
 	*cur_off = mtd->oobsize + mtd->writesize;
 }
 
-static inline u32 sunxi_nfc_buf_to_user_data(const u8 *buf)
-{
-	return buf[0] | (buf[1] << 8) | (buf[2] << 16) | (buf[3] << 24);
-}
-
 static int sunxi_nfc_hw_ecc_write_chunk(struct mtd_info *mtd,
 					const u8 *data, int data_off,
 					const u8 *oob, int oob_off,

@@ -919,19 +983,6 @@ static int sunxi_nfc_hw_ecc_write_chunk(struct mtd_info *mtd,
 
 	sunxi_nfc_randomizer_write_buf(mtd, data, ecc->size, false, page);
 
-	/* Fill OOB data in */
-	if ((nand->options & NAND_NEED_SCRAMBLING) && bbm) {
-		u8 user_data[4];
-
-		memcpy(user_data, oob, 4);
-		sunxi_nfc_randomize_bbm(mtd, page, user_data);
-		writel(sunxi_nfc_buf_to_user_data(user_data),
-		       nfc->regs + NFC_REG_USER_DATA(0));
-	} else {
-		writel(sunxi_nfc_buf_to_user_data(oob),
-		       nfc->regs + NFC_REG_USER_DATA(0));
-	}
-
 	if (data_off + ecc->size != oob_off)
 		nand->cmdfunc(mtd, NAND_CMD_RNDIN, oob_off, -1);
 

@@ -940,6 +991,8 @@ static int sunxi_nfc_hw_ecc_write_chunk(struct mtd_info *mtd,
 		return ret;
 
 	sunxi_nfc_randomizer_enable(mtd);
+	sunxi_nfc_hw_ecc_set_prot_oob_bytes(mtd, oob, 0, bbm, page);
+
 	writel(NFC_DATA_TRANS | NFC_DATA_SWAP_METHOD |
 	       NFC_ACCESS_DIR | NFC_ECC_OP,
 	       nfc->regs + NFC_REG_CMD);

index f6ea0fb..3e7b919 100644
@@ -867,7 +867,7 @@ static int sunxi_nfc_hw_ecc_read_chunk(struct mtd_info *mtd,
 				       u8 *oob, int oob_off,
 				       int *cur_off,
 				       unsigned int *max_bitflips,
-				       bool bbm, int page)
+				       bool bbm, bool oob_required, int page)
 {
 	struct nand_chip *nand = mtd_to_nand(mtd);
 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);

@@ -899,7 +899,7 @@ static int sunxi_nfc_hw_ecc_read_chunk(struct mtd_info *mtd,
 
 	*cur_off = oob_off + ecc->bytes + 4;
 
-	ret = sunxi_nfc_hw_ecc_correct(mtd, data, oob, 0,
+	ret = sunxi_nfc_hw_ecc_correct(mtd, data, oob_required ? oob : NULL, 0,
 				       readl(nfc->regs + NFC_REG_ECC_ST),
 				       &erased);
 	if (erased)

@@ -929,12 +929,14 @@ static int sunxi_nfc_hw_ecc_read_chunk(struct mtd_info *mtd,
 	} else {
 		memcpy_fromio(data, nfc->regs + NFC_RAM0_BASE, ecc->size);
 
-		nand->cmdfunc(mtd, NAND_CMD_RNDOUT, oob_off, -1);
-		sunxi_nfc_randomizer_read_buf(mtd, oob, ecc->bytes + 4,
-					      true, page);
+		if (oob_required) {
+			nand->cmdfunc(mtd, NAND_CMD_RNDOUT, oob_off, -1);
+			sunxi_nfc_randomizer_read_buf(mtd, oob, ecc->bytes + 4,
+						      true, page);
 
-		sunxi_nfc_hw_ecc_get_prot_oob_bytes(mtd, oob, 0,
-						    bbm, page);
+			sunxi_nfc_hw_ecc_get_prot_oob_bytes(mtd, oob, 0,
+							    bbm, page);
+		}
 	}
 
 	sunxi_nfc_hw_ecc_update_stats(mtd, max_bitflips, ret);

@@ -1048,7 +1050,7 @@ static int sunxi_nfc_hw_ecc_read_page(struct mtd_info *mtd,
 		ret = sunxi_nfc_hw_ecc_read_chunk(mtd, data, data_off, oob,
 						  oob_off + mtd->writesize,
 						  &cur_off, &max_bitflips,
-						  !i, page);
+						  !i, oob_required, page);
 		if (ret < 0)
 			return ret;
 		else if (ret)

@@ -1086,8 +1088,8 @@ static int sunxi_nfc_hw_ecc_read_subpage(struct mtd_info *mtd,
 		ret = sunxi_nfc_hw_ecc_read_chunk(mtd, data, data_off,
 						  oob,
 						  oob_off + mtd->writesize,
-						  &cur_off, &max_bitflips,
-						  !i, page);
+						  &cur_off, &max_bitflips, !i,
+						  false, page);
 		if (ret < 0)
 			return ret;
 	}

@@ -1149,7 +1151,9 @@ static int sunxi_nfc_hw_syndrome_ecc_read_page(struct mtd_info *mtd,
 
 		ret = sunxi_nfc_hw_ecc_read_chunk(mtd, data, data_off, oob,
 						  oob_off, &cur_off,
-						  &max_bitflips, !i, page);
+						  &max_bitflips, !i,
+						  oob_required,
+						  page);
 		if (ret < 0)
 			return ret;
 		else if (ret)

index 3e7b919..6d6b166 100644
@@ -956,7 +956,7 @@ static void sunxi_nfc_hw_ecc_read_extra_oob(struct mtd_info *mtd,
 	if (len <= 0)
 		return;
 
-	if (*cur_off != offset)
+	if (!cur_off || *cur_off != offset)
 		nand->cmdfunc(mtd, NAND_CMD_RNDOUT,
 			      offset + mtd->writesize, -1);
 

@@ -966,7 +966,8 @@ static void sunxi_nfc_hw_ecc_read_extra_oob(struct mtd_info *mtd,
 		sunxi_nfc_randomizer_read_buf(mtd, oob + offset, len,
 					      false, page);
 
-	*cur_off = mtd->oobsize + mtd->writesize;
+	if (cur_off)
+		*cur_off = mtd->oobsize + mtd->writesize;
 }
 
 static int sunxi_nfc_hw_ecc_write_chunk(struct mtd_info *mtd,

@@ -1021,13 +1022,14 @@ static void sunxi_nfc_hw_ecc_write_extra_oob(struct mtd_info *mtd,
 	if (len <= 0)
 		return;
 
-	if (*cur_off != offset)
+	if (!cur_off || *cur_off != offset)
 		nand->cmdfunc(mtd, NAND_CMD_RNDIN,
 			      offset + mtd->writesize, -1);
 
 	sunxi_nfc_randomizer_write_buf(mtd, oob + offset, len, false, page);
 
-	*cur_off = mtd->oobsize + mtd->writesize;
+	if (cur_off)
+		*cur_off = mtd->oobsize + mtd->writesize;
 }
 
 static int sunxi_nfc_hw_ecc_read_page(struct mtd_info *mtd,

index 556ec1e..4a75362 100644
@@ -41,6 +41,27 @@ struct sg_table {
 	unsigned int orig_nents;	/* original size of list */
 };
 
+/**
+ * struct sg_constraints - SG constraints structure
+ *
+ * @max_chunk_len: maximum chunk buffer length. Each SG entry has to be smaller
+ *		   than this value. Zero means no constraint.
+ * @required_alignment: minimum alignment. Is used for both size and pointer
+ *			alignment. If this constraint is not met, the function
+ *			should return -EINVAL.
+ * @preferred_alignment: preferred alignment. Mainly used to optimize
+ *			 throughput when the DMA engine performs better when
+ *			 doing aligned accesses.
+ *
+ * This structure is here to help sg_alloc_table_from_buf() create the optimal
+ * SG list based on DMA engine constraints.
+ */
+struct sg_constraints {
+	size_t max_chunk_len;
+	size_t required_alignment;
+	size_t preferred_alignment;
+};
+
 /*
  * Notes on SG table design.
  *

@@ -265,6 +286,9 @@ int sg_alloc_table_from_pages(struct sg_table *sgt,
 	struct page **pages, unsigned int n_pages,
 	unsigned long offset, unsigned long size,
 	gfp_t gfp_mask);
+int sg_alloc_table_from_buf(struct sg_table *sgt, const void *buf, size_t len,
+			    const struct sg_constraints *constraints,
+			    gfp_t gfp_mask);
 
 size_t sg_copy_buffer(struct scatterlist *sgl, unsigned int nents, void *buf,
 		      size_t buflen, off_t skip, bool to_buffer);

167 lines not on this page · raw message

index 3096251..3c368f0 100644
@@ -1253,6 +1253,72 @@ void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size)
 }
 EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to);
 
+#ifdef CONFIG_HAS_DMA
+/**
+ * mtd_map_buf - create an SG table and prepare it for DMA operations
+ *
+ * @mtd: mtd device description object pointer
+ * @dev: device handling the DMA operation
+ * @buf: buf used to create the SG table
+ * @len: length of buf
+ * @constraints: optional constraints to take into account when creating
+ *		 the SG table. Can be NULL if no specific constraints
+ *		 are required.
+ * @dir: direction of the DMA operation
+ *
+ * This function should be used when an MTD driver wants to do DMA operations
+ * on a buffer passed by the MTD layer. This functions takes care of
+ * vmallocated buffer constraints, and return and sg_table that you can safely
+ * use.
+ */
+int mtd_map_buf(struct mtd_info *mtd, struct device *dev,
+		struct sg_table *sgt, const void *buf, size_t len,
+		const struct sg_constraints *constraints,
+		enum dma_data_direction dir)
+{
+	int ret;
+
+	ret = sg_alloc_table_from_buf(sgt, buf, len, constraints, GFP_KERNEL);
+	if (ret)
+		return ret;
+
+	ret = dma_map_sg(dev, sgt->sgl, sgt->nents, dir);
+	if (!ret)
+		ret = -ENOMEM;
+
+	if (ret < 0) {
+		sg_free_table(sgt);
+		return ret;
+	}
+
+	sgt->nents = ret;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(mtd_map_buf);
+
+/**
+ * mtd_map_buf - unmap an SG table and release its resources
+ *
+ * @mtd: mtd device description object pointer
+ * @dev: device handling the DMA operation
+ * @sgt: SG table
+ * @dir: direction of the DMA operation
+ *
+ * This function unmaps a previously mapped SG table and release SG table
+ * resources. Should be called when your DMA operation is done.
+ */
+void mtd_unmap_buf(struct mtd_info *mtd, struct device *dev,
+		   struct sg_table *sgt, enum dma_data_direction dir)
+{
+	if (sgt->orig_nents) {
+		dma_unmap_sg(dev, sgt->sgl, sgt->orig_nents, dir);
+		sg_free_table(sgt);
+	}
+}
+EXPORT_SYMBOL_GPL(mtd_unmap_buf);
+#endif /* !CONFIG_HAS_DMA */
+
 #ifdef CONFIG_PROC_FS
 
 /*====================================================================*/

index 7712721..15cff85 100644
@@ -24,6 +24,7 @@
 #include <linux/uio.h>
 #include <linux/notifier.h>
 #include <linux/device.h>
+#include <linux/dma-mapping.h>
 
 #include <mtd/mtd-abi.h>
 

@@ -410,6 +411,30 @@ extern void register_mtd_user (struct mtd_notifier *new);
 extern int unregister_mtd_user (struct mtd_notifier *old);
 void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size);
 
+#ifdef CONFIG_HAS_DMA
+int mtd_map_buf(struct mtd_info *mtd, struct device *dev,
+		struct sg_table *sgt, const void *buf, size_t len,
+		const struct sg_constraints *constraints,
+		enum dma_data_direction dir);
+void mtd_unmap_buf(struct mtd_info *mtd, struct device *dev,
+		   struct sg_table *sgt, enum dma_data_direction dir);
+#else
+static inline int mtd_map_buf(struct mtd_info *mtd, struct device *dev,
+			      struct sg_table *sgt, const void *buf,
+			      size_t len,
+			      const struct sg_constraints *constraints
+			      enum dma_data_direction dir)
+{
+	return -ENOTSUPP;
+}
+
+static void mtd_unmap_buf(struct mtd_info *mtd, struct device *dev,
+			  struct sg_table *sgt, enum dma_data_direction dir)
+{
+	return -ENOTSUPP;
+}
+#endif
+
 void mtd_erase_callback(struct erase_info *instr);
 
 static inline int mtd_is_bitflip(int err) {

index 6d6b166..1029f28 100644
@@ -154,6 +154,7 @@
 
 /* define bit use in NFC_ECC_ST */
 #define NFC_ECC_ERR(x)		BIT(x)
+#define NFC_ECC_ERR_MSK		GENMASK(15, 0)
 #define NFC_ECC_PAT_FOUND(x)	BIT(x + 16)
 #define NFC_ECC_ERR_CNT(b, x)	(((x) >> (((b) % 4) * 8)) & 0xff)
 

@@ -277,6 +278,7 @@ struct sunxi_nfc {
 	unsigned long clk_rate;
 	struct list_head chips;
 	struct completion complete;
+	struct dma_chan *dmac;
 };
 
 static inline struct sunxi_nfc *to_sunxi_nfc(struct nand_hw_control *ctrl)

@@ -369,6 +371,68 @@ static int sunxi_nfc_rst(struct sunxi_nfc *nfc)
 	return ret;
 }
 
+static int sunxi_nfc_dma_op_prepare(struct mtd_info *mtd, const void *buf,
+				    int chunksize, int nchunks,
+				    enum dma_data_direction ddir,
+				    struct sg_table *sgt)
+{
+	struct nand_chip *nand = mtd_to_nand(mtd);
+	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
+	struct dma_async_tx_descriptor *dmad;
+	enum dma_transfer_direction tdir;
+	dma_cookie_t dmat;
+	int ret;
+
+	if (ddir == DMA_FROM_DEVICE)
+		tdir = DMA_DEV_TO_MEM;
+	else
+		tdir = DMA_MEM_TO_DEV;
+
+	ret = mtd_map_buf(mtd, nfc->dev, sgt, buf, nchunks * chunksize,
+			  NULL, ddir);
+	if (ret)
+		return ret;
+
+	dmad = dmaengine_prep_slave_sg(nfc->dmac, sgt->sgl, sgt->nents,
+				       tdir, DMA_CTRL_ACK);
+	if (IS_ERR(dmad)) {
+		ret = PTR_ERR(dmad);
+		goto err_unmap_buf;
+	}
+
+	writel(readl(nfc->regs + NFC_REG_CTL) | NFC_RAM_METHOD,
+	       nfc->regs + NFC_REG_CTL);
+	writel(nchunks, nfc->regs + NFC_REG_SECTOR_NUM);
+	writel(chunksize, nfc->regs + NFC_REG_CNT);
+	dmat = dmaengine_submit(dmad);
+
+	ret = dma_submit_error(dmat);
+	if (ret)
+		goto err_clr_dma_flag;
+
+	return 0;
+
+err_clr_dma_flag:
+	writel(readl(nfc->regs + NFC_REG_CTL) & ~NFC_RAM_METHOD,
+	       nfc->regs + NFC_REG_CTL);
+
+err_unmap_buf:
+	mtd_unmap_buf(mtd, nfc->dev, sgt, ddir);
+	return ret;
+}
+
+static void sunxi_nfc_dma_op_cleanup(struct mtd_info *mtd,
+				     enum dma_data_direction ddir,
+				     struct sg_table *sgt)
+{
+	struct nand_chip *nand = mtd_to_nand(mtd);
+	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
+
+	mtd_unmap_buf(mtd, nfc->dev, sgt, ddir);
+	writel(readl(nfc->regs + NFC_REG_CTL) & ~NFC_RAM_METHOD,
+	       nfc->regs + NFC_REG_CTL);
+}
+
 static int sunxi_nfc_dev_ready(struct mtd_info *mtd)
 {
 	struct nand_chip *nand = mtd_to_nand(mtd);

@@ -970,6 +1034,128 @@ static void sunxi_nfc_hw_ecc_read_extra_oob(struct mtd_info *mtd,
 		*cur_off = mtd->oobsize + mtd->writesize;
 }
 
+static int sunxi_nfc_hw_ecc_read_chunks_dma(struct mtd_info *mtd, uint8_t *buf,
+					    int oob_required, int page,
+					    int nchunks)
+{
+	struct nand_chip *nand = mtd_to_nand(mtd);
+	bool randomized = nand->options & NAND_NEED_SCRAMBLING;
+	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
+	struct nand_ecc_ctrl *ecc = &nand->ecc;
+	unsigned int max_bitflips = 0;
+	int ret, i, raw_mode = 0;
+	struct sg_table sgt;
+	u32 status;
+
+	ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
+	if (ret)
+		return ret;
+
+	ret = sunxi_nfc_dma_op_prepare(mtd, buf, ecc->size, nchunks,
+				       DMA_FROM_DEVICE, &sgt);
+	if (ret)
+		return ret;
+
+	sunxi_nfc_hw_ecc_enable(mtd);
+	sunxi_nfc_randomizer_config(mtd, page, false);
+	sunxi_nfc_randomizer_enable(mtd);
+
+	writel((NAND_CMD_RNDOUTSTART << 16) | (NAND_CMD_RNDOUT << 8) |
+	       NAND_CMD_READSTART, nfc->regs + NFC_REG_RCMD_SET);
+
+	dma_async_issue_pending(nfc->dmac);
+
+	writel(NFC_PAGE_OP | NFC_DATA_SWAP_METHOD | NFC_DATA_TRANS,
+	       nfc->regs + NFC_REG_CMD);
+
+	ret = sunxi_nfc_wait_events(nfc, NFC_CMD_INT_FLAG, true, 0);
+	if (ret)
+		dmaengine_terminate_all(nfc->dmac);
+
+	sunxi_nfc_randomizer_disable(mtd);
+	sunxi_nfc_hw_ecc_disable(mtd);
+
+	sunxi_nfc_dma_op_cleanup(mtd, DMA_FROM_DEVICE, &sgt);
+
+	if (ret)
+		return ret;
+
+	status = readl(nfc->regs + NFC_REG_ECC_ST);
+
+	for (i = 0; i < nchunks; i++) {
+		int data_off = i * ecc->size;
+		int oob_off = i * (ecc->bytes + 4);
+		u8 *data = buf + data_off;
+		u8 *oob = nand->oob_poi + oob_off;
+		bool erased;
+
+		ret = sunxi_nfc_hw_ecc_correct(mtd, randomized ? data : NULL,
+					       oob_required ? oob : NULL,
+					       i, status, &erased);
+
+		/* ECC errors are handled in the second loop. */
+		if (ret < 0)
+			continue;
+
+		if (oob_required && !erased) {
+			/* TODO: use DMA to retrieve OOB */
+			nand->cmdfunc(mtd, NAND_CMD_RNDOUT, oob_off, -1);
+			nand->read_buf(mtd, oob, ecc->bytes + 4);
+
+			sunxi_nfc_hw_ecc_get_prot_oob_bytes(mtd, oob, i,
+							    !i, page);
+		}
+
+		if (erased)
+			raw_mode = 1;
+
+		sunxi_nfc_hw_ecc_update_stats(mtd, &max_bitflips, ret);
+	}
+
+	if (status & NFC_ECC_ERR_MSK) {
+		for (i = 0; i < nchunks; i++) {
+			int data_off = i * ecc->size;
+			int oob_off = i * (ecc->bytes + 4);
+			u8 *data = buf + data_off;
+			u8 *oob = nand->oob_poi + oob_off;
+
+			if (!(status & NFC_ECC_ERR(i)))
+				continue;
+
+			/*
+			 * Re-read the data with the randomizer disabled to
+			 * identify bitflips in erased pages.
+			 */
+			if (randomized) {
+				/* TODO: use DMA to read page in raw mode */
+				nand->cmdfunc(mtd, NAND_CMD_RNDOUT,
+					      data_off, -1);
+				nand->read_buf(mtd, data, ecc->size);
+			}
+
+			/* TODO: use DMA to retrieve OOB */
+			nand->cmdfunc(mtd, NAND_CMD_RNDOUT, oob_off, -1);
+			nand->read_buf(mtd, oob, ecc->bytes + 4);
+
+			ret = nand_check_erased_ecc_chunk(data,	ecc->size,
+							  oob, ecc->bytes + 4,
+							  NULL, 0,
+							  ecc->strength);
+			if (ret >= 0)
+				raw_mode = 1;
+
+			sunxi_nfc_hw_ecc_update_stats(mtd, &max_bitflips, ret);
+		}
+	}
+
+	if (oob_required)
+		sunxi_nfc_hw_ecc_read_extra_oob(mtd, nand->oob_poi,
+						NULL, !raw_mode,
+						page);
+
+	return max_bitflips;
+}
+
 static int sunxi_nfc_hw_ecc_write_chunk(struct mtd_info *mtd,
 					const u8 *data, int data_off,
 					const u8 *oob, int oob_off,

@@ -1068,6 +1254,23 @@ static int sunxi_nfc_hw_ecc_read_page(struct mtd_info *mtd,
 	return max_bitflips;
 }
 
+static int sunxi_nfc_hw_ecc_read_page_dma(struct mtd_info *mtd,
+					  struct nand_chip *chip, u8 *buf,
+					  int oob_required, int page)
+{
+	int ret;
+
+	ret = sunxi_nfc_hw_ecc_read_chunks_dma(mtd, buf, oob_required, page,
+					       chip->ecc.steps);
+	if (ret >= 0)
+		return ret;
+
+	/* Fallback to PIO mode */
+	chip->cmdfunc(mtd, NAND_CMD_RNDOUT, 0, -1);
+
+	return sunxi_nfc_hw_ecc_read_page(mtd, chip, buf, oob_required, page);
+}
+
 static int sunxi_nfc_hw_ecc_read_subpage(struct mtd_info *mtd,
 					 struct nand_chip *chip,
 					 u32 data_offs, u32 readlen,

@@ -1101,6 +1304,25 @@ static int sunxi_nfc_hw_ecc_read_subpage(struct mtd_info *mtd,
 	return max_bitflips;
 }
 
+static int sunxi_nfc_hw_ecc_read_subpage_dma(struct mtd_info *mtd,
+					     struct nand_chip *chip,
+					     u32 data_offs, u32 readlen,
+					     u8 *buf, int page)
+{
+	int nchunks = DIV_ROUND_UP(data_offs + readlen, chip->ecc.size);
+	int ret;
+
+	ret = sunxi_nfc_hw_ecc_read_chunks_dma(mtd, buf, false, page, nchunks);
+	if (ret >= 0)
+		return ret;
+
+	/* Fallback to PIO mode */
+	chip->cmdfunc(mtd, NAND_CMD_RNDOUT, 0, -1);
+
+	return sunxi_nfc_hw_ecc_read_subpage(mtd, chip, data_offs, readlen,
+					     buf, page);
+}
+
 static int sunxi_nfc_hw_ecc_write_page(struct mtd_info *mtd,
 				       struct nand_chip *chip,
 				       const uint8_t *buf, int oob_required,

@@ -1133,6 +1355,69 @@ static int sunxi_nfc_hw_ecc_write_page(struct mtd_info *mtd,
 	return 0;
 }
 
+static int sunxi_nfc_hw_ecc_write_page_dma(struct mtd_info *mtd,
+					   struct nand_chip *chip,
+					   const u8 *buf,
+					   int oob_required,
+					   int page)
+{
+	struct nand_chip *nand = mtd_to_nand(mtd);
+	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
+	struct nand_ecc_ctrl *ecc = &nand->ecc;
+	struct sg_table sgt;
+	int ret, i;
+
+	ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
+	if (ret)
+		return ret;
+
+	ret = sunxi_nfc_dma_op_prepare(mtd, buf, ecc->size, ecc->steps,
+				       DMA_TO_DEVICE, &sgt);
+	if (ret)
+		goto pio_fallback;
+
+	for (i = 0; i < ecc->steps; i++) {
+		const u8 *oob = nand->oob_poi + (i * (ecc->bytes + 4));
+
+		sunxi_nfc_hw_ecc_set_prot_oob_bytes(mtd, oob, i, !i, page);
+	}
+
+	sunxi_nfc_hw_ecc_enable(mtd);
+	sunxi_nfc_randomizer_config(mtd, page, false);
+	sunxi_nfc_randomizer_enable(mtd);
+
+	writel((NAND_CMD_RNDIN << 8) | NAND_CMD_PAGEPROG,
+	       nfc->regs + NFC_REG_RCMD_SET);
+
+	dma_async_issue_pending(nfc->dmac);
+
+	writel(NFC_PAGE_OP | NFC_DATA_SWAP_METHOD |
+	       NFC_DATA_TRANS | NFC_ACCESS_DIR,
+	       nfc->regs + NFC_REG_CMD);
+
+	ret = sunxi_nfc_wait_events(nfc, NFC_CMD_INT_FLAG, true, 0);
+	if (ret)
+		dmaengine_terminate_all(nfc->dmac);
+
+	sunxi_nfc_randomizer_disable(mtd);
+	sunxi_nfc_hw_ecc_disable(mtd);
+
+	sunxi_nfc_dma_op_cleanup(mtd, DMA_TO_DEVICE, &sgt);
+
+	if (ret)
+		return ret;
+
+	if (oob_required || (chip->options & NAND_NEED_SCRAMBLING))
+		/* TODO: use DMA to transfer extra OOB bytes ? */
+		sunxi_nfc_hw_ecc_write_extra_oob(mtd, chip->oob_poi,
+						 NULL, page);
+
+	return 0;
+
+pio_fallback:
+	return sunxi_nfc_hw_ecc_write_page(mtd, chip, buf, oob_required, page);
+}
+
 static int sunxi_nfc_hw_syndrome_ecc_read_page(struct mtd_info *mtd,
 					       struct nand_chip *chip,
 					       uint8_t *buf, int oob_required,

@@ -1506,6 +1791,9 @@ static int sunxi_nand_hw_ecc_ctrl_init(struct mtd_info *mtd,
 				       struct nand_ecc_ctrl *ecc,
 				       struct device_node *np)
 {
+	struct nand_chip *nand = mtd_to_nand(mtd);
+	struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand);
+	struct sunxi_nfc *nfc = to_sunxi_nfc(sunxi_nand->nand.controller);
 	struct nand_ecclayout *layout;
 	int nsectors;
 	int i, j;

@@ -1515,11 +1803,19 @@ static int sunxi_nand_hw_ecc_ctrl_init(struct mtd_info *mtd,
 	if (ret)
 		return ret;
 
-	ecc->read_page = sunxi_nfc_hw_ecc_read_page;
-	ecc->write_page = sunxi_nfc_hw_ecc_write_page;
+	if (nfc->dmac) {
+		ecc->read_page = sunxi_nfc_hw_ecc_read_page_dma;
+		ecc->read_subpage = sunxi_nfc_hw_ecc_read_subpage_dma;
+		ecc->write_page = sunxi_nfc_hw_ecc_write_page_dma;
+	} else {
+		ecc->read_page = sunxi_nfc_hw_ecc_read_page;
+		ecc->read_subpage = sunxi_nfc_hw_ecc_read_subpage;
+		ecc->write_page = sunxi_nfc_hw_ecc_write_page;
+	}
+
+	/* TODO: support DMA for raw accesses */
 	ecc->read_oob_raw = nand_read_oob_std;
 	ecc->write_oob_raw = nand_write_oob_std;
-	ecc->read_subpage = sunxi_nfc_hw_ecc_read_subpage;
 	layout = ecc->layout;
 	nsectors = mtd->writesize / ecc->size;
 

@@ -1893,16 +2189,34 @@ static int sunxi_nfc_probe(struct platform_device *pdev)
 	if (ret)
 		goto out_mod_clk_unprepare;
 
+	nfc->dmac = dma_request_slave_channel(dev, "rxtx");
+	if (nfc->dmac) {
+		struct dma_slave_config dmac_cfg = { };
+
+		dmac_cfg.src_addr = r->start + NFC_REG_IO_DATA;
+		dmac_cfg.dst_addr = dmac_cfg.src_addr;
+		dmac_cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+		dmac_cfg.dst_addr_width = dmac_cfg.src_addr_width;
+		dmac_cfg.src_maxburst = 4;
+		dmac_cfg.dst_maxburst = 4;
+		dmaengine_slave_config(nfc->dmac, &dmac_cfg);
+	} else {
+		dev_warn(dev, "failed to request rxtx DMA channel\n");
+	}
+
 	platform_set_drvdata(pdev, nfc);
 
 	ret = sunxi_nand_chips_init(dev, nfc);
 	if (ret) {
 		dev_err(dev, "failed to init nand chips\n");
-		goto out_mod_clk_unprepare;
+		goto out_release_dmac;
 	}
 
 	return 0;
 
+out_release_dmac:
+	if (nfc->dmac)
+		dma_release_channel(nfc->dmac);
 out_mod_clk_unprepare:
 	clk_disable_unprepare(nfc->mod_clk);
 out_ahb_clk_unprepare:

@@ -1916,6 +2230,8 @@ static int sunxi_nfc_remove(struct platform_device *pdev)
 	struct sunxi_nfc *nfc = platform_get_drvdata(pdev);
 
 	sunxi_nand_chips_cleanup(nfc);
+	if (nfc->dmac)
+		dma_release_channel(nfc->dmac);
 	clk_disable_unprepare(nfc->mod_clk);
 	clk_disable_unprepare(nfc->ahb_clk);