diff --git a/drivers/pci/controller/pcie-rockchip-ep.c b/drivers/pci/controller/pcie-rockchip-ep.c
index 24ee1df17a49d..5a4279591f790 100644
--- a/drivers/pci/controller/pcie-rockchip-ep.c
+++ b/drivers/pci/controller/pcie-rockchip-ep.c
@@ -238,6 +238,28 @@ static inline u32 rockchip_ob_region(phys_addr_t addr)
 	return (addr >> ilog2(SZ_1M)) & 0x1f;
 }
 
+static u64 rockchip_pcie_ep_align_addr(struct pci_epc *epc, u64 pci_addr,
+				       size_t *pci_size, size_t *addr_offset)
+{
+	struct rockchip_pcie_ep *ep = epc_get_drvdata(epc);
+	size_t size = *pci_size;
+	u64 offset, mask;
+	int num_bits;
+
+	num_bits = rockchip_pcie_ep_ob_atu_num_bits(&ep->rockchip,
+						    pci_addr, size);
+	mask = (1ULL << num_bits) - 1;
+
+	offset = pci_addr & mask;
+	if (size + offset > SZ_1M)
+		size = SZ_1M - offset;
+
+	*pci_size = ALIGN(offset + size, ROCKCHIP_PCIE_AT_SIZE_ALIGN);
+	*addr_offset = offset;
+
+	return pci_addr & ~mask;
+}
+
 static int rockchip_pcie_ep_map_addr(struct pci_epc *epc, u8 fn, u8 vfn,
 				     phys_addr_t addr, u64 pci_addr,
 				     size_t size)
@@ -461,6 +483,7 @@ static const struct pci_epc_ops rockchip_pcie_epc_ops = {
 	.write_header	= rockchip_pcie_ep_write_header,
 	.set_bar	= rockchip_pcie_ep_set_bar,
 	.clear_bar	= rockchip_pcie_ep_clear_bar,
+	.align_addr	= rockchip_pcie_ep_align_addr,
 	.map_addr	= rockchip_pcie_ep_map_addr,
 	.unmap_addr	= rockchip_pcie_ep_unmap_addr,
 	.set_msi	= rockchip_pcie_ep_set_msi,
diff --git a/drivers/pci/controller/pcie-rockchip.h b/drivers/pci/controller/pcie-rockchip.h
index 02368ce9bd548..30398156095f9 100644
--- a/drivers/pci/controller/pcie-rockchip.h
+++ b/drivers/pci/controller/pcie-rockchip.h
@@ -241,6 +241,11 @@
 #define   ROCKCHIP_PCIE_EP_MSIX_CAP_CP_MASK		GENMASK(15, 8)
 #define ROCKCHIP_PCIE_EP_DUMMY_IRQ_ADDR				0x1
 #define ROCKCHIP_PCIE_EP_PCI_LEGACY_IRQ_ADDR		0x3
+
+#define ROCKCHIP_PCIE_AT_MIN_NUM_BITS	8
+#define ROCKCHIP_PCIE_AT_MAX_NUM_BITS	20
+#define ROCKCHIP_PCIE_AT_SIZE_ALIGN	(1UL << ROCKCHIP_PCIE_AT_MIN_NUM_BITS)
+
 #define ROCKCHIP_PCIE_EP_FUNC_BASE(fn) \
 	(PCIE_EP_PF_CONFIG_REGS_BASE + (((fn) << 12) & GENMASK(19, 12)))
 #define ROCKCHIP_PCIE_EP_VIRT_FUNC_BASE(fn) \