[PATCH v2] pci: xilinx: Enable MMIO region

[Mayuresh Chitale <mchitale@ventanamicro.com>]

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>
---
Changes in v2:
====
Add Reviewed-by Tag.

 drivers/pci/pcie_xilinx.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/pci/pcie_xilinx.c b/drivers/pci/pcie_xilinx.c
index c1f5bbbb1b..7052d6dac8 100644
--- a/drivers/pci/pcie_xilinx.c
+++ b/drivers/pci/pcie_xilinx.c
@@ -23,6 +23,8 @@ 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
@@ -140,6 +142,7 @@ 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)
@@ -147,6 +150,11 @@ static int pcie_xilinx_of_to_plat(struct udevice *dev)
 
 	pcie->cfg_base = devm_ioremap(dev, addr, size);
 
+	/* 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;
 }
 
-- 
2.34.1