[PATCH v4 3/7] PCI: cadence: HPA: Add post-link delay

The Cadence HPA (High Performance Architecture IP) specific link setup
function cdns_pcie_hpa_host_link_setup() waits for the link to come up
but does not implement the required 100 ms delay after link training
completes for speeds > 5.0 GT/s (PCIe r6.0 sec 6.6.1).

Add a call to pci_host_common_link_train_delay() immediately after the
link is confirmed to be up, using the max_link_speed field. Also, in the
HPA host setup function, read the device tree property "max-link-speed"
to initialize max_link_speed if not already set by a glue driver.

This ensures compliance for HPA-based platforms.

Signed-off-by: Hans Zhang <[email protected]>
---
 drivers/pci/controller/cadence/pcie-cadence-host-hpa.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/pci/controller/cadence/pcie-cadence-host-hpa.c b/drivers/pci/controller/cadence/pcie-cadence-host-hpa.c
index 0f540bed58e8..8ef58ed01daa 100644
--- a/drivers/pci/controller/cadence/pcie-cadence-host-hpa.c
+++ b/drivers/pci/controller/cadence/pcie-cadence-host-hpa.c
@@ -15,6 +15,8 @@
 
 #include "pcie-cadence.h"
 #include "pcie-cadence-host-common.h"
+#include "../pci-host-common.h"
+#include "../../pci.h"
 
 static u8 bar_aperture_mask[] = {
 	[RP_BAR0] = 0x3F,
@@ -304,6 +306,8 @@ int cdns_pcie_hpa_host_link_setup(struct cdns_pcie_rc *rc)
 	ret = cdns_pcie_host_wait_for_link(pcie, cdns_pcie_hpa_link_up);
 	if (ret)
 		dev_dbg(dev, "PCIe link never came up\n");
+	else
+		pci_host_common_link_train_delay(pcie->max_link_speed);
 
 	return ret;
 }
@@ -313,6 +317,7 @@ int cdns_pcie_hpa_host_setup(struct cdns_pcie_rc *rc)
 {
 	struct device *dev = rc->pcie.dev;
 	struct platform_device *pdev = to_platform_device(dev);
+	struct device_node *np = dev->of_node;
 	struct pci_host_bridge *bridge;
 	enum   cdns_pcie_rp_bar bar;
 	struct cdns_pcie *pcie;
@@ -343,6 +348,9 @@ int cdns_pcie_hpa_host_setup(struct cdns_pcie_rc *rc)
 		rc->cfg_res = res;
 	}
 
+	if (pcie->max_link_speed < 1)
+		pcie->max_link_speed = of_pci_get_max_link_speed(np);
+
 	/* Put EROM Bar aperture to 0 */
 	cdns_pcie_hpa_writel(pcie, REG_BANK_IP_CFG_CTRL_REG, CDNS_PCIE_EROM, 0x0);
 
-- 
2.43.0