PCI: dwc: ep: Call dw_pcie_ep_init_registers() API directly from all glue drivers

Currently, dw_pcie_ep_init_registers() API is directly called by the glue
drivers requiring active refclk from host. But for the other drivers, it is
getting called implicitly by dw_pcie_ep_init(). This is due to the fact
that this API initializes DWC EP specific registers and that requires an
active refclk (either from host or generated locally by endpoint itsef).

But, this causes a discrepancy among the glue drivers. So to avoid this
confusion, let's call this API directly from all glue drivers irrespective
of refclk dependency. Only difference here is that the drivers requiring
refclk from host will call this API only after the refclk is received and
other drivers without refclk dependency will call this API right after
dw_pcie_ep_init().

With this change, the check for 'core_init_notifier' flag can now be
dropped from dw_pcie_ep_init() API. This will also allow us to remove the
'core_init_notifier' flag completely in the later commits.

Link: https://lore.kernel.org/linux-pci/20240327-pci-dbi-rework-v12-7-082625472414@linaro.org
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Niklas Cassel <cassel@kernel.org>
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>

1 files changed, 11 insertions, 1 deletions

diff --git a/drivers/pci/controller/dwc/pcie-rcar-gen4.c b/drivers/pci/controller/dwc/pcie-rcar-gen4.c
index de4bdfaecab3..e155a905fb4f 100644
--- a/drivers/pci/controller/dwc/pcie-rcar-gen4.c
+++ b/drivers/pci/controller/dwc/pcie-rcar-gen4.c
@@ -416,6 +416,7 @@ static const struct dw_pcie_ep_ops pcie_ep_ops = {
 static int rcar_gen4_add_dw_pcie_ep(struct rcar_gen4_pcie *rcar)
 {
 	struct dw_pcie_ep *ep = &rcar->dw.ep;
+	struct device *dev = rcar->dw.dev;
 	int ret;
 
 	if (!IS_ENABLED(CONFIG_PCIE_RCAR_GEN4_EP))
@@ -424,8 +425,17 @@ static int rcar_gen4_add_dw_pcie_ep(struct rcar_gen4_pcie *rcar)
 	ep->ops = &pcie_ep_ops;
 
 	ret = dw_pcie_ep_init(ep);
-	if (ret)
+	if (ret) {
 		rcar_gen4_pcie_ep_deinit(rcar);
+		return ret;
+	}
+
+	ret = dw_pcie_ep_init_registers(ep);
+	if (ret) {
+		dev_err(dev, "Failed to initialize DWC endpoint registers\n");
+		dw_pcie_ep_deinit(ep);
+		rcar_gen4_pcie_ep_deinit(rcar);
+	}
 
 	return ret;
 }