PCI: keystone: Add start_link()/stop_link() dw_pcie_ops

Add start_link()/stop_link() dw_pcie_ops and invoke ks_pcie_start_link()
directly from host_init. start_link()/stop_link() ops are required for
adding EP mode support.
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

drivers/pci/controller/dwc/pci-keystone.c

@@ -460,18 +460,33 @@ static int ks_pcie_link_up(struct dw_pcie *pci)
 	return (val == PORT_LOGIC_LTSSM_STATE_L0);
 }
 
-static void ks_pcie_initiate_link_train(struct keystone_pcie *ks_pcie)
+static void ks_pcie_stop_link(struct dw_pcie *pci)
 {
+	struct keystone_pcie *ks_pcie = to_keystone_pcie(pci);
 	u32 val;
 
 	/* Disable Link training */
 	val = ks_pcie_app_readl(ks_pcie, CMD_STATUS);
 	val &= ~LTSSM_EN_VAL;
 	ks_pcie_app_writel(ks_pcie, CMD_STATUS, LTSSM_EN_VAL | val);
+}
+
+static int ks_pcie_start_link(struct dw_pcie *pci)
+{
+	struct keystone_pcie *ks_pcie = to_keystone_pcie(pci);
+	struct device *dev = pci->dev;
+	u32 val;
+
+	if (dw_pcie_link_up(pci)) {
+		dev_dbg(dev, "link is already up\n");
+		return 0;
+	}
 
 	/* Initiate Link Training */
 	val = ks_pcie_app_readl(ks_pcie, CMD_STATUS);
 	ks_pcie_app_writel(ks_pcie, CMD_STATUS, LTSSM_EN_VAL | val);
+
+	return 0;
 }
 
 /**
@@ -556,26 +571,6 @@ static void ks_pcie_quirk(struct pci_dev *dev)
 }
 DECLARE_PCI_FIXUP_ENABLE(PCI_ANY_ID, PCI_ANY_ID, ks_pcie_quirk);
 
-static int ks_pcie_establish_link(struct keystone_pcie *ks_pcie)
-{
-	struct dw_pcie *pci = ks_pcie->pci;
-	struct device *dev = pci->dev;
-
-	if (dw_pcie_link_up(pci)) {
-		dev_info(dev, "Link already up\n");
-		return 0;
-	}
-
-	ks_pcie_initiate_link_train(ks_pcie);
-
-	/* check if the link is up or not */
-	if (!dw_pcie_wait_for_link(pci))
-		return 0;
-
-	dev_err(dev, "phy link never came up\n");
-	return -ETIMEDOUT;
-}
-
 static void ks_pcie_msi_irq_handler(struct irq_desc *desc)
 {
 	unsigned int irq = desc->irq_data.hwirq;
@@ -813,7 +808,7 @@ static int __init ks_pcie_host_init(struct pcie_port *pp)
 
 	dw_pcie_setup_rc(pp);
 
-	ks_pcie_establish_link(ks_pcie);
+	ks_pcie_stop_link(pci);
 	ks_pcie_setup_rc_app_regs(ks_pcie);
 	ks_pcie_setup_interrupts(ks_pcie);
 	writew(PCI_IO_RANGE_TYPE_32 | (PCI_IO_RANGE_TYPE_32 << 8),
@@ -830,6 +825,9 @@ static int __init ks_pcie_host_init(struct pcie_port *pp)
 	hook_fault_code(17, ks_pcie_fault, SIGBUS, 0,
 			"Asynchronous external abort");
 
+	ks_pcie_start_link(pci);
+	dw_pcie_wait_for_link(pci);
+
 	return 0;
 }
 
@@ -892,6 +890,8 @@ static const struct of_device_id ks_pcie_of_match[] = {
 };
 
 static const struct dw_pcie_ops ks_pcie_dw_pcie_ops = {
+	.start_link = ks_pcie_start_link,
+	.stop_link = ks_pcie_stop_link,
 	.link_up = ks_pcie_link_up,
 };