From: Hyun Kwon hyun.kwon@xilinx.com

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.

Fixes: ab597d35ef11 ("PCI: xilinx-nwl: Add support for Xilinx NWL PCIe Host Controller") Cc: stable@vger.kernel.org Signed-off-by: Hyun Kwon hyun.kwon@xilinx.com Signed-off-by: Bharat Kumar Gogada bharat.kumar.gogada@xilinx.com Signed-off-by: Michal Simek michal.simek@xilinx.com ---

Changes in v3: - use PCIe instead of pcie - add stable cc - update commit message - reported by Krzysztof

Changes in v2: - Update commit message - reported by Krzysztof - Check return value from clk_prepare_enable() - reported by Krzysztof

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 8689311c5ef6..1c3d5b87ef20 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 <linux/clk.h> #include <linux/delay.h> #include <linux/interrupt.h> #include <linux/irq.h> @@ -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");