PCI: cadence: Extract link setup sequence from cdns_pcie_host_setup()

The function cdns_pcie_host_setup() mixes probe structure and link setup.

The link setup must be done during the resume sequence. So extract it from
cdns_pcie_host_setup() and create a dedicated function.

Link: https://lore.kernel.org/linux-pci/20240102-j7200-pcie-s2r-v7-1-a2f9156da6c3@bootlin.com
Signed-off-by: Thomas Richard <thomas.richard@bootlin.com>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Reviewed-by: Siddharth Vadapalli <s-vadapalli@ti.com>

Author: thom24

drivers/pci/controller/cadence/pcie-cadence-host.c

@@ -497,6 +497,30 @@ static int cdns_pcie_host_init(struct device *dev,
 	return cdns_pcie_host_init_address_translation(rc);
 }
 
+int cdns_pcie_host_link_setup(struct cdns_pcie_rc *rc)
+{
+	struct cdns_pcie *pcie = &rc->pcie;
+	struct device *dev = rc->pcie.dev;
+	int ret;
+
+	if (rc->quirk_detect_quiet_flag)
+		cdns_pcie_detect_quiet_min_delay_set(&rc->pcie);
+
+	cdns_pcie_host_enable_ptm_response(pcie);
+
+	ret = cdns_pcie_start_link(pcie);
+	if (ret) {
+		dev_err(dev, "Failed to start link\n");
+		return ret;
+	}
+
+	ret = cdns_pcie_host_start_link(rc);
+	if (ret)
+		dev_dbg(dev, "PCIe link never came up\n");
+
+	return 0;
+}
+
 int cdns_pcie_host_setup(struct cdns_pcie_rc *rc)
 {
 	struct device *dev = rc->pcie.dev;
@@ -533,20 +557,9 @@ int cdns_pcie_host_setup(struct cdns_pcie_rc *rc)
 		return PTR_ERR(rc->cfg_base);
 	rc->cfg_res = res;
 
-	if (rc->quirk_detect_quiet_flag)
-		cdns_pcie_detect_quiet_min_delay_set(&rc->pcie);
-
-	cdns_pcie_host_enable_ptm_response(pcie);
-
-	ret = cdns_pcie_start_link(pcie);
-	if (ret) {
-		dev_err(dev, "Failed to start link\n");
-		return ret;
-	}
-
-	ret = cdns_pcie_host_start_link(rc);
+	ret = cdns_pcie_host_link_setup(rc);
 	if (ret)
-		dev_dbg(dev, "PCIe link never came up\n");
+		return ret;
 
 	for (bar = RP_BAR0; bar <= RP_NO_BAR; bar++)
 		rc->avail_ib_bar[bar] = true;

drivers/pci/controller/cadence/pcie-cadence.h

@@ -521,10 +521,16 @@ static inline bool cdns_pcie_link_up(struct cdns_pcie *pcie)
 }
 
 #ifdef CONFIG_PCIE_CADENCE_HOST
+int cdns_pcie_host_link_setup(struct cdns_pcie_rc *rc);
 int cdns_pcie_host_setup(struct cdns_pcie_rc *rc);
 void __iomem *cdns_pci_map_bus(struct pci_bus *bus, unsigned int devfn,
 			       int where);
 #else
+static inline int cdns_pcie_host_link_setup(struct cdns_pcie_rc *rc)
+{
+	return 0;
+}
+
 static inline int cdns_pcie_host_setup(struct cdns_pcie_rc *rc)
 {
 	return 0;