From 4d79e367185dc8e3f83525a38b77e36fac69a85e Mon Sep 17 00:00:00 2001 From: Michal Simek Date: Fri, 25 Jun 2021 12:48:22 +0200 Subject: [PATCH 1/2] dt-bindings: pci: xilinx-nwl: Document optional clock property Clock property hasn't been documented in binding document but it is used for quite a long time where clock was specified by commit 9c8a47b484ed ("arm64: dts: xilinx: Add the clock nodes for zynqmp"). Link: https://lore.kernel.org/r/67aa2c189337181bb2d7721fb616db5640587d2a.1624618100.git.michal.simek@xilinx.com Signed-off-by: Michal Simek Signed-off-by: Lorenzo Pieralisi Acked-by: Rob Herring --- Documentation/devicetree/bindings/pci/xilinx-nwl-pcie.txt | 1 + 1 file changed, 1 insertion(+) diff --git a/Documentation/devicetree/bindings/pci/xilinx-nwl-pcie.txt b/Documentation/devicetree/bindings/pci/xilinx-nwl-pcie.txt index 2d677e90a7e29..f56f8c58c5d94 100644 --- a/Documentation/devicetree/bindings/pci/xilinx-nwl-pcie.txt +++ b/Documentation/devicetree/bindings/pci/xilinx-nwl-pcie.txt @@ -35,6 +35,7 @@ Required properties: Optional properties: - dma-coherent: present if DMA operations are coherent +- clocks: Input clock specifier. Refer to common clock bindings Example: ++++++++ From de0a01f5296651d3a539f2d23d0db8f359483696 Mon Sep 17 00:00:00 2001 From: Hyun Kwon Date: Fri, 25 Jun 2021 12:48:23 +0200 Subject: [PATCH 2/2] PCI: xilinx-nwl: Enable the clock through CCF Enable PCIe reference clock. There is no remove function that's why this should be enough for simple operation. Normally this clock is enabled by default by firmware but there are usecases where this clock should be enabled by driver itself. It is also good that PCIe clock is recorded in a clock framework. Link: https://lore.kernel.org/r/ee6997a08fab582b1c6de05f8be184f3fe8d5357.1624618100.git.michal.simek@xilinx.com Fixes: ab597d35ef11 ("PCI: xilinx-nwl: Add support for Xilinx NWL PCIe Host Controller") Signed-off-by: Hyun Kwon Signed-off-by: Bharat Kumar Gogada Signed-off-by: Michal Simek Signed-off-by: Lorenzo Pieralisi Cc: stable@vger.kernel.org --- drivers/pci/controller/pcie-xilinx-nwl.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/drivers/pci/controller/pcie-xilinx-nwl.c b/drivers/pci/controller/pcie-xilinx-nwl.c index 8689311c5ef66..1c3d5b87ef20e 100644 --- a/drivers/pci/controller/pcie-xilinx-nwl.c +++ b/drivers/pci/controller/pcie-xilinx-nwl.c @@ -6,6 +6,7 @@ * (C) Copyright 2014 - 2015, Xilinx, Inc. */ +#include #include #include #include @@ -169,6 +170,7 @@ struct nwl_pcie { u8 last_busno; struct nwl_msi msi; struct irq_domain *legacy_irq_domain; + struct clk *clk; raw_spinlock_t leg_mask_lock; }; @@ -823,6 +825,16 @@ static int nwl_pcie_probe(struct platform_device *pdev) return err; } + pcie->clk = devm_clk_get(dev, NULL); + if (IS_ERR(pcie->clk)) + return PTR_ERR(pcie->clk); + + err = clk_prepare_enable(pcie->clk); + if (err) { + dev_err(dev, "can't enable PCIe ref clock\n"); + return err; + } + err = nwl_pcie_bridge_init(pcie); if (err) { dev_err(dev, "HW Initialization failed\n");