[PATCH v2 4/5] PCI: imx6: add PCIe embedded DMA support

[Frank Li <Frank.Li@nxp.com>]

Add support for the DMA controller in the DesignWare PCIe core

The DMA can transfer data to any remote address location
regardless PCI address space size.

Prepare struct dw_edma_chip() and call dw_edma_probe()

Signed-off-by: Frank Li <Frank.Li@nxp.com>
---

This patch depended on some ep enable patch for imx.

Change from v1 to v2
- rework commit message
- align dw_edma_chip change

 drivers/pci/controller/dwc/pci-imx6.c | 51 +++++++++++++++++++++++++++
 1 file changed, 51 insertions(+)

diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index efa8b81711090..7dc55986c947d 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -38,6 +38,7 @@
 #include "../../pci.h"
 
 #include "pcie-designware.h"
+#include "linux/dma/edma.h"
 
 #define IMX8MQ_PCIE_LINK_CAP_REG_OFFSET		0x7c
 #define IMX8MQ_PCIE_LINK_CAP_L1EL_64US		GENMASK(18, 17)
@@ -164,6 +165,8 @@ struct imx6_pcie {
 	const struct imx6_pcie_drvdata *drvdata;
 	struct regulator	*epdev_on;
 	struct phy		*phy;
+
+	struct dw_edma_chip	dma_chip;
 };
 
 /* Parameters for the waiting for PCIe PHY PLL to lock on i.MX7 */
@@ -2031,6 +2034,51 @@ static const struct dw_pcie_ep_ops pcie_ep_ops = {
 	.get_features = imx_pcie_ep_get_features,
 };
 
+static int imx_dma_irq_vector(struct device *dev, unsigned int nr)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+
+	return platform_get_irq_byname(pdev, "dma");
+}
+
+static struct dw_edma_core_ops dma_ops = {
+	.irq_vector = imx_dma_irq_vector,
+};
+
+static int imx_add_pcie_dma(struct imx6_pcie *imx6_pcie)
+{
+	unsigned int pcie_dma_offset;
+	struct dw_pcie *pci = imx6_pcie->pci;
+	struct device *dev = pci->dev;
+	struct dw_edma_chip *dma = &imx6_pcie->dma_chip;
+	int i = 0;
+	int sz = PAGE_SIZE;
+
+	pcie_dma_offset = 0x970;
+
+	dma->dev = dev;
+
+	dma->reg_base = pci->dbi_base + pcie_dma_offset;
+
+	dma->ops = &dma_ops;
+	dma->nr_irqs = 1;
+
+	dma->flags = DW_EDMA_CHIP_NO_MSI | DW_EDMA_CHIP_REG32BIT | DW_EDMA_CHIP_LOCAL_EP;
+
+	dma->ll_wr_cnt = dma->ll_rd_cnt=1;
+	dma->ll_region_wr[0].sz = sz;
+	dma->ll_region_wr[0].vaddr = dmam_alloc_coherent(dev, sz,
+							 &dma->ll_region_wr[i].paddr,
+							 GFP_KERNEL);
+
+	dma->ll_region_rd[0].sz = sz;
+	dma->ll_region_rd[0].vaddr = dmam_alloc_coherent(dev, sz,
+							 &dma->ll_region_rd[i].paddr,
+							 GFP_KERNEL);
+
+	return dw_edma_probe(dma);
+}
+
 static int imx_add_pcie_ep(struct imx6_pcie *imx6_pcie,
 					struct platform_device *pdev)
 {
@@ -2694,6 +2742,9 @@ static int imx6_pcie_probe(struct platform_device *pdev)
 		goto err_ret;
 	}
 
+	if (imx_add_pcie_dma(imx6_pcie))
+		dev_info(dev, "pci edma probe failure\n");
+
 	return 0;
 
 err_ret:
-- 
2.24.0.rc1