From: Hyun Kwon hyun.kwon@xilinx.com
commit de0a01f5296651d3a539f2d23d0db8f359483696 upstream.
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/ee6997a08fab582b1c6de05f8be184f3fe8d5357.162461810... Fixes: ab597d35ef11 ("PCI: xilinx-nwl: Add support for Xilinx NWL PCIe Host Controller") 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 Signed-off-by: Lorenzo Pieralisi lorenzo.pieralisi@arm.com Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/pci/controller/pcie-xilinx-nwl.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)
--- 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 root_busno; struct nwl_msi msi; struct irq_domain *legacy_irq_domain; + struct clk *clk; raw_spinlock_t leg_mask_lock; };
@@ -839,6 +841,16 @@ static int nwl_pcie_probe(struct platfor 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");