pci: xilinx: Enable MMIO region

The host bridge MMIO region is disabled by default due to which MMIO
accesses cause an exception. Fix it by setting the bridge enable bit.
This change is ported from the linux pcie-xilinx driver.

Signed-off-by: Mayuresh Chitale <mchitale@ventanamicro.com>
Reviewed-by: Michal Simek <michal.simek@amd.com>
Link: https://lore.kernel.org/r/20231116165103.140968-3-mchitale@ventanamicro.com
Signed-off-by: Michal Simek <michal.simek@amd.com>

diff --git a/drivers/pci/pcie_xilinx.c b/drivers/pci/pcie_xilinx.c
index fdc9b08..3db460b 100644 (file)
--- a/drivers/pci/pcie_xilinx.c
+++ b/drivers/pci/pcie_xilinx.c
@@ -24,6 +24,8 @@ struct xilinx_pcie {
 /* Register definitions */
 #define XILINX_PCIE_REG_PSCR           0x144
 #define XILINX_PCIE_REG_PSCR_LNKUP     BIT(11)
+#define XILINX_PCIE_REG_RPSC           0x148
+#define XILINX_PCIE_REG_RPSC_BEN       BIT(0)
 
 /**
  * pcie_xilinx_link_up() - Check whether the PCIe link is up
@@ -141,6 +143,7 @@ static int pcie_xilinx_of_to_plat(struct udevice *dev)
        struct xilinx_pcie *pcie = dev_get_priv(dev);
        fdt_addr_t addr;
        fdt_size_t size;
+       u32 rpsc;
 
        addr = dev_read_addr_size(dev, &size);
        if (addr == FDT_ADDR_T_NONE)
@@ -150,6 +153,11 @@ static int pcie_xilinx_of_to_plat(struct udevice *dev)
        if (IS_ERR(pcie->cfg_base))
                return PTR_ERR(pcie->cfg_base);
 
+       /* Enable the Bridge enable bit */
+       rpsc = __raw_readl(pcie->cfg_base + XILINX_PCIE_REG_RPSC);
+       rpsc |= XILINX_PCIE_REG_RPSC_BEN;
+       __raw_writel(rpsc, pcie->cfg_base + XILINX_PCIE_REG_RPSC);
+
        return 0;
 }