The latest eDMA IP development implements a Vendor-Specific Extended
Capability that contains the eDMA BAR, offset, map format, and the
number of read/write channels available.

Signed-off-by: Gustavo Pimentel <gustavo.pimen...@synopsys.com>
---
 drivers/dma/dw-edma/dw-edma-core.c |  20 ++++---
 drivers/dma/dw-edma/dw-edma-pcie.c | 116 ++++++++++++++++++++++++++++---------
 2 files changed, 101 insertions(+), 35 deletions(-)

diff --git a/drivers/dma/dw-edma/dw-edma-core.c 
b/drivers/dma/dw-edma/dw-edma-core.c
index 08d71da..18a2878 100644
--- a/drivers/dma/dw-edma/dw-edma-core.c
+++ b/drivers/dma/dw-edma/dw-edma-core.c
@@ -863,15 +863,19 @@ int dw_edma_probe(struct dw_edma_chip *chip)
 
        raw_spin_lock_init(&dw->lock);
 
-       /* Find out how many write channels are supported by hardware */
-       dw->wr_ch_cnt = dw_edma_v0_core_ch_count(dw, EDMA_DIR_WRITE);
-       if (!dw->wr_ch_cnt)
-               return -EINVAL;
+       if (!dw->wr_ch_cnt) {
+               /* Find out how many write channels are supported by hardware */
+               dw->wr_ch_cnt = dw_edma_v0_core_ch_count(dw, EDMA_DIR_WRITE);
+               if (!dw->wr_ch_cnt)
+                       return -EINVAL;
+       }
 
-       /* Find out how many read channels are supported by hardware */
-       dw->rd_ch_cnt = dw_edma_v0_core_ch_count(dw, EDMA_DIR_READ);
-       if (!dw->rd_ch_cnt)
-               return -EINVAL;
+       if (!dw->rd_ch_cnt) {
+               /* Find out how many read channels are supported by hardware */
+               dw->rd_ch_cnt = dw_edma_v0_core_ch_count(dw, EDMA_DIR_READ);
+               if (!dw->rd_ch_cnt)
+                       return -EINVAL;
+       }
 
        dev_vdbg(dev, "Channels:\twrite=%d, read=%d\n",
                 dw->wr_ch_cnt, dw->rd_ch_cnt);
diff --git a/drivers/dma/dw-edma/dw-edma-pcie.c 
b/drivers/dma/dw-edma/dw-edma-pcie.c
index c130549..eb6f8b3 100644
--- a/drivers/dma/dw-edma/dw-edma-pcie.c
+++ b/drivers/dma/dw-edma/dw-edma-pcie.c
@@ -13,9 +13,16 @@
 #include <linux/dma/edma.h>
 #include <linux/pci-epf.h>
 #include <linux/msi.h>
+#include <linux/bitfield.h>
 
 #include "dw-edma-core.h"
 
+#define DW_PCIE_VSEC_DMA_ID                    0x6
+#define DW_PCIE_VSEC_DMA_BAR                   GENMASK(10, 8)
+#define DW_PCIE_VSEC_DMA_MAP                   GENMASK(2, 0)
+#define DW_PCIE_VSEC_DMA_RD_CH                 GENMASK(25, 16)
+#define DW_PCIE_VSEC_DMA_WR_CH                 GENMASK(9, 0)
+
 struct dw_edma_pcie_data {
        /* eDMA registers location */
        enum pci_barno                  rg_bar;
@@ -32,6 +39,8 @@ struct dw_edma_pcie_data {
        /* Other */
        enum dw_edma_map_format         mf;
        u8                              irqs;
+       u16                             rd_ch_cnt;
+       u16                             wr_ch_cnt;
 };
 
 static const struct dw_edma_pcie_data snps_edda_data = {
@@ -50,6 +59,8 @@ static const struct dw_edma_pcie_data snps_edda_data = {
        /* Other */
        .mf                             = EDMA_MF_EDMA_UNROLL,
        .irqs                           = 1,
+       .rd_ch_cnt                      = 0,
+       .wr_ch_cnt                      = 0,
 };
 
 static int dw_edma_pcie_irq_vector(struct device *dev, unsigned int nr)
@@ -61,10 +72,51 @@ static const struct dw_edma_core_ops dw_edma_pcie_core_ops 
= {
        .irq_vector = dw_edma_pcie_irq_vector,
 };
 
+static void dw_edma_pcie_get_vsec_dma_data(struct pci_dev *pdev,
+                                          struct dw_edma_pcie_data *pdata)
+{
+       u32 val, map;
+       u16 vsec;
+       u64 off;
+
+       vsec = pci_find_vsec_capability(pdev, PCI_VENDOR_ID_SYNOPSYS,
+                                       DW_PCIE_VSEC_DMA_ID);
+       if (!vsec)
+               return;
+
+       pci_read_config_dword(pdev, vsec + PCI_VNDR_HEADER, &val);
+       if (PCI_VNDR_HEADER_REV(val) != 0x00 ||
+           PCI_VNDR_HEADER_LEN(val) != 0x18)
+               return;
+
+       pci_dbg(pdev, "Detected PCIe Vendor-Specific Extended Capability 
DMA\n");
+       pci_read_config_dword(pdev, vsec + 0x8, &val);
+       map = FIELD_GET(DW_PCIE_VSEC_DMA_MAP, val);
+       if (map != EDMA_MF_EDMA_LEGACY &&
+           map != EDMA_MF_EDMA_UNROLL &&
+           map != EDMA_MF_HDMA_COMPAT)
+               return;
+
+       pdata->mf = map;
+       pdata->rg_bar = FIELD_GET(DW_PCIE_VSEC_DMA_BAR, val);
+
+       pci_read_config_dword(pdev, vsec + 0xc, &val);
+       pdata->rd_ch_cnt = FIELD_GET(DW_PCIE_VSEC_DMA_RD_CH, val);
+       pdata->wr_ch_cnt = FIELD_GET(DW_PCIE_VSEC_DMA_WR_CH, val);
+
+       pci_read_config_dword(pdev, vsec + 0x14, &val);
+       off = val;
+       pci_read_config_dword(pdev, vsec + 0x10, &val);
+       off <<= 32;
+       off |= val;
+       pdata->rg_off = off;
+}
+
 static int dw_edma_pcie_probe(struct pci_dev *pdev,
                              const struct pci_device_id *pid)
 {
-       const struct dw_edma_pcie_data *pdata = (void *)pid->driver_data;
+       struct dw_edma_pcie_data *pdata = (void *)pid->driver_data;
+       struct dw_edma_pcie_data vsec_data;
        struct device *dev = &pdev->dev;
        struct dw_edma_chip *chip;
        struct dw_edma *dw;
@@ -77,10 +129,18 @@ static int dw_edma_pcie_probe(struct pci_dev *pdev,
                return err;
        }
 
+       memcpy(&vsec_data, pdata, sizeof(struct dw_edma_pcie_data));
+
+       /*
+        * Tries to find if exists a PCIe Vendor-Specific Extended Capability
+        * for the DMA, if one exists, then reconfigures it.
+        */
+       dw_edma_pcie_get_vsec_dma_data(pdev, &vsec_data);
+
        /* Mapping PCI BAR regions */
-       err = pcim_iomap_regions(pdev, BIT(pdata->rg_bar) |
-                                      BIT(pdata->ll_bar) |
-                                      BIT(pdata->dt_bar),
+       err = pcim_iomap_regions(pdev, BIT(vsec_data.rg_bar) |
+                                      BIT(vsec_data.ll_bar) |
+                                      BIT(vsec_data.dt_bar),
                                 pci_name(pdev));
        if (err) {
                pci_err(pdev, "eDMA BAR I/O remapping failed\n");
@@ -123,7 +183,7 @@ static int dw_edma_pcie_probe(struct pci_dev *pdev,
                return -ENOMEM;
 
        /* IRQs allocation */
-       nr_irqs = pci_alloc_irq_vectors(pdev, 1, pdata->irqs,
+       nr_irqs = pci_alloc_irq_vectors(pdev, 1, vsec_data.irqs,
                                        PCI_IRQ_MSI | PCI_IRQ_MSIX);
        if (nr_irqs < 1) {
                pci_err(pdev, "fail to alloc IRQ vector (number of IRQs=%u)\n",
@@ -137,27 +197,29 @@ static int dw_edma_pcie_probe(struct pci_dev *pdev,
        chip->id = pdev->devfn;
        chip->irq = pdev->irq;
 
-       dw->rg_region.vaddr = pcim_iomap_table(pdev)[pdata->rg_bar];
-       dw->rg_region.vaddr += pdata->rg_off;
-       dw->rg_region.paddr = pdev->resource[pdata->rg_bar].start;
-       dw->rg_region.paddr += pdata->rg_off;
-       dw->rg_region.sz = pdata->rg_sz;
-
-       dw->ll_region.vaddr = pcim_iomap_table(pdev)[pdata->ll_bar];
-       dw->ll_region.vaddr += pdata->ll_off;
-       dw->ll_region.paddr = pdev->resource[pdata->ll_bar].start;
-       dw->ll_region.paddr += pdata->ll_off;
-       dw->ll_region.sz = pdata->ll_sz;
-
-       dw->dt_region.vaddr = pcim_iomap_table(pdev)[pdata->dt_bar];
-       dw->dt_region.vaddr += pdata->dt_off;
-       dw->dt_region.paddr = pdev->resource[pdata->dt_bar].start;
-       dw->dt_region.paddr += pdata->dt_off;
-       dw->dt_region.sz = pdata->dt_sz;
-
-       dw->mf = pdata->mf;
+       dw->rg_region.vaddr = pcim_iomap_table(pdev)[vsec_data.rg_bar];
+       dw->rg_region.vaddr += vsec_data.rg_off;
+       dw->rg_region.paddr = pdev->resource[vsec_data.rg_bar].start;
+       dw->rg_region.paddr += vsec_data.rg_off;
+       dw->rg_region.sz = vsec_data.rg_sz;
+
+       dw->ll_region.vaddr = pcim_iomap_table(pdev)[vsec_data.ll_bar];
+       dw->ll_region.vaddr += vsec_data.ll_off;
+       dw->ll_region.paddr = pdev->resource[vsec_data.ll_bar].start;
+       dw->ll_region.paddr += vsec_data.ll_off;
+       dw->ll_region.sz = vsec_data.ll_sz;
+
+       dw->dt_region.vaddr = pcim_iomap_table(pdev)[vsec_data.dt_bar];
+       dw->dt_region.vaddr += vsec_data.dt_off;
+       dw->dt_region.paddr = pdev->resource[vsec_data.dt_bar].start;
+       dw->dt_region.paddr += vsec_data.dt_off;
+       dw->dt_region.sz = vsec_data.dt_sz;
+
+       dw->mf = vsec_data.mf;
        dw->nr_irqs = nr_irqs;
        dw->ops = &dw_edma_pcie_core_ops;
+       dw->rd_ch_cnt = vsec_data.rd_ch_cnt;
+       dw->wr_ch_cnt = vsec_data.wr_ch_cnt;
 
        /* Debug info */
        if (dw->mf == EDMA_MF_EDMA_LEGACY)
@@ -170,15 +232,15 @@ static int dw_edma_pcie_probe(struct pci_dev *pdev,
                pci_dbg(pdev, "Version:\tUnknown (0x%x)\n", dw->mf);
 
        pci_dbg(pdev, "Registers:\tBAR=%u, off=0x%.8lx, sz=0x%zx bytes, 
addr(v=%p, p=%pa)\n",
-               pdata->rg_bar, pdata->rg_off, pdata->rg_sz,
+               vsec_data.rg_bar, vsec_data.rg_off, vsec_data.rg_sz,
                dw->rg_region.vaddr, &dw->rg_region.paddr);
 
        pci_dbg(pdev, "L. List:\tBAR=%u, off=0x%.8lx, sz=0x%zx bytes, 
addr(v=%p, p=%pa)\n",
-               pdata->ll_bar, pdata->ll_off, pdata->ll_sz,
+               vsec_data.ll_bar, vsec_data.ll_off, vsec_data.ll_sz,
                dw->ll_region.vaddr, &dw->ll_region.paddr);
 
        pci_dbg(pdev, "Data:\tBAR=%u, off=0x%.8lx, sz=0x%zx bytes, addr(v=%p, 
p=%pa)\n",
-               pdata->dt_bar, pdata->dt_off, pdata->dt_sz,
+               vsec_data.dt_bar, vsec_data.dt_off, vsec_data.dt_sz,
                dw->dt_region.vaddr, &dw->dt_region.paddr);
 
        pci_dbg(pdev, "Nr. IRQs:\t%u\n", dw->nr_irqs);
-- 
2.7.4

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