mtd: rawnand: sunxi: Add MDMA support

index 2a7ca3072f35..21c4ae93075a 100644
@@ -51,6 +51,7 @@
 #define NFC_REG_USER_DATA(x)	(0x0050 + ((x) * 4))
 #define NFC_REG_SPARE_AREA	0x00A0
 #define NFC_REG_PAT_ID		0x00A4
+#define NFC_REG_MDMA_ADDR	0x00C0
 #define NFC_REG_MDMA_CNT	0x00C4
 #define NFC_RAM0_BASE		0x0400
 #define NFC_RAM1_BASE		0x0800

@@ -207,13 +208,13 @@ static inline struct sunxi_nand_chip *to_sunxi_nand(struct nand_chip *nand)
  * NAND Controller capabilities structure: stores NAND controller capabilities
  * for distinction between compatible strings.
  *
- * @extra_mbus_conf:	Contrary to A10, A10s and A13, accessing internal RAM
+ * @has_mdma:		Use mbus dma mode, otherwise general dma
  *			through MBUS on A23/A33 needs extra configuration.
  * @reg_io_data:	I/O data register
  * @dma_maxburst:	DMA maxburst
  */
 struct sunxi_nfc_caps {
-	bool extra_mbus_conf;
+	bool has_mdma;
 	unsigned int reg_io_data;
 	unsigned int dma_maxburst;
 };

@@ -363,24 +364,34 @@ static int sunxi_nfc_dma_op_prepare(struct sunxi_nfc *nfc, const void *buf,
 	if (!ret)
 		return -ENOMEM;
 
-	dmad = dmaengine_prep_slave_sg(nfc->dmac, sg, 1, tdir, DMA_CTRL_ACK);
-	if (!dmad) {
-		ret = -EINVAL;
-		goto err_unmap_buf;
+	if (!nfc->caps->has_mdma) {
+		dmad = dmaengine_prep_slave_sg(nfc->dmac, sg, 1, tdir, DMA_CTRL_ACK);
+		if (!dmad) {
+			ret = -EINVAL;
+			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);
-	if (nfc->caps->extra_mbus_conf)
+
+	if (nfc->caps->has_mdma) {
+		writel(readl(nfc->regs + NFC_REG_CTL) & ~NFC_DMA_TYPE_NORMAL,
+		       nfc->regs + NFC_REG_CTL);
 		writel(chunksize * nchunks, nfc->regs + NFC_REG_MDMA_CNT);
+		writel(sg_dma_address(sg), nfc->regs + NFC_REG_MDMA_ADDR);
+	} else {
+		writel(readl(nfc->regs + NFC_REG_CTL) | NFC_DMA_TYPE_NORMAL,
+		       nfc->regs + NFC_REG_CTL);
 
-	dmat = dmaengine_submit(dmad);
+		dmat = dmaengine_submit(dmad);
 
-	ret = dma_submit_error(dmat);
-	if (ret)
-		goto err_clr_dma_flag;
+		ret = dma_submit_error(dmat);
+		if (ret)
+			goto err_clr_dma_flag;
+	}
 
 	return 0;
 

@@ -911,7 +922,7 @@ static int sunxi_nfc_hw_ecc_read_chunks_dma(struct nand_chip *nand, uint8_t *buf
 	unsigned int max_bitflips = 0;
 	int ret, i, raw_mode = 0;
 	struct scatterlist sg;
-	u32 status;
+	u32 status, wait;
 
 	ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
 	if (ret)

@@ -929,13 +940,18 @@ static int sunxi_nfc_hw_ecc_read_chunks_dma(struct nand_chip *nand, uint8_t *buf
 	writel((NAND_CMD_RNDOUTSTART << 16) | (NAND_CMD_RNDOUT << 8) |
 	       NAND_CMD_READSTART, nfc->regs + NFC_REG_RCMD_SET);
 
-	dma_async_issue_pending(nfc->dmac);
+	wait = NFC_CMD_INT_FLAG;
+
+	if (nfc->caps->has_mdma)
+		wait |= NFC_DMA_INT_FLAG;
+	else
+		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, false, 0);
-	if (ret)
+	ret = sunxi_nfc_wait_events(nfc, wait, false, 0);
+	if (ret && !nfc->caps->has_mdma)
 		dmaengine_terminate_all(nfc->dmac);
 
 	sunxi_nfc_randomizer_disable(nand);

@@ -1276,6 +1292,7 @@ static int sunxi_nfc_hw_ecc_write_page_dma(struct nand_chip *nand,
 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
 	struct nand_ecc_ctrl *ecc = &nand->ecc;
 	struct scatterlist sg;
+	u32 wait;
 	int ret, i;
 
 	sunxi_nfc_select_chip(nand, nand->cur_cs);

@@ -1304,14 +1321,19 @@ static int sunxi_nfc_hw_ecc_write_page_dma(struct nand_chip *nand,
 	writel((NAND_CMD_RNDIN << 8) | NAND_CMD_PAGEPROG,
 	       nfc->regs + NFC_REG_WCMD_SET);
 
-	dma_async_issue_pending(nfc->dmac);
+	wait = NFC_CMD_INT_FLAG;
+
+	if (nfc->caps->has_mdma)
+		wait |= NFC_DMA_INT_FLAG;
+	else
+		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, false, 0);
-	if (ret)
+	ret = sunxi_nfc_wait_events(nfc, wait, false, 0);
+	if (ret && !nfc->caps->has_mdma)
 		dmaengine_terminate_all(nfc->dmac);
 
 	sunxi_nfc_randomizer_disable(nand);

@@ -1695,7 +1717,7 @@ static int sunxi_nand_hw_ecc_ctrl_init(struct nand_chip *nand,
 	mtd_set_ooblayout(mtd, &sunxi_nand_ooblayout_ops);
 	ecc->priv = data;
 
-	if (nfc->dmac) {
+	if (nfc->dmac || nfc->caps->has_mdma) {
 		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;

@@ -2058,6 +2080,36 @@ static void sunxi_nand_chips_cleanup(struct sunxi_nfc *nfc)
 	}
 }
 
+static int sunxi_nfc_dma_init(struct sunxi_nfc *nfc, struct resource *r)
+{
+	int ret;
+
+	if (nfc->caps->has_mdma)
+		return 0;
+
+	nfc->dmac = dma_request_chan(nfc->dev, "rxtx");
+	if (IS_ERR(nfc->dmac)) {
+		ret = PTR_ERR(nfc->dmac);
+		if (ret == -EPROBE_DEFER)
+			return ret;
+
+		/* Ignore errors to fall back to PIO mode */
+		dev_warn(nfc->dev, "failed to request rxtx DMA channel: %d\n", ret);
+		nfc->dmac = NULL;
+	} else {
+		struct dma_slave_config dmac_cfg = { };
+
+		dmac_cfg.src_addr = r->start + nfc->caps->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 = nfc->caps->dma_maxburst;
+		dmac_cfg.dst_maxburst = nfc->caps->dma_maxburst;
+		dmaengine_slave_config(nfc->dmac, &dmac_cfg);
+	}
+	return 0;
+}
+
 static int sunxi_nfc_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;

@@ -2132,30 +2184,10 @@ static int sunxi_nfc_probe(struct platform_device *pdev)
 	if (ret)
 		goto out_ahb_reset_reassert;
 
-	nfc->dmac = dma_request_chan(dev, "rxtx");
-	if (IS_ERR(nfc->dmac)) {
-		ret = PTR_ERR(nfc->dmac);
-		if (ret == -EPROBE_DEFER)
-			goto out_ahb_reset_reassert;
-
-		/* Ignore errors to fall back to PIO mode */
-		dev_warn(dev, "failed to request rxtx DMA channel: %d\n", ret);
-		nfc->dmac = NULL;
-	} else {
-		struct dma_slave_config dmac_cfg = { };
+	ret = sunxi_nfc_dma_init(nfc, r);
 
-		dmac_cfg.src_addr = r->start + nfc->caps->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 = nfc->caps->dma_maxburst;
-		dmac_cfg.dst_maxburst = nfc->caps->dma_maxburst;
-		dmaengine_slave_config(nfc->dmac, &dmac_cfg);
-
-		if (nfc->caps->extra_mbus_conf)
-			writel(readl(nfc->regs + NFC_REG_CTL) |
-			       NFC_DMA_TYPE_NORMAL, nfc->regs + NFC_REG_CTL);
-	}
+	if (ret)
+		goto out_ahb_reset_reassert;
 
 	platform_set_drvdata(pdev, nfc);
 

@@ -2202,7 +2234,7 @@ static const struct sunxi_nfc_caps sunxi_nfc_a10_caps = {
 };
 
 static const struct sunxi_nfc_caps sunxi_nfc_a23_caps = {
-	.extra_mbus_conf = true,
+	.has_mdma = true,
 	.reg_io_data = NFC_REG_A23_IO_DATA,
 	.dma_maxburst = 8,
 };