PCI: j721e: Add support to provide refclk to PCIe connector

Add support to provide refclk to PCIe connector.

Link: https://lore.kernel.org/r/20210308063550.6227-5-kishon@ti.com
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

diff --git a/drivers/pci/controller/cadence/pci-j721e.c b/drivers/pci/controller/cadence/pci-j721e.c
index 849f1e4..9c102ef 100644 (file)
--- a/drivers/pci/controller/cadence/pci-j721e.c
+++ b/drivers/pci/controller/cadence/pci-j721e.c
@@ -6,6 +6,7 @@
  * Author: Kishon Vijay Abraham I <kishon@ti.com>
  */
 
+#include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/gpio/consumer.h>
 #include <linux/io.h>
@@ -50,6 +51,7 @@ enum link_status {
 
 struct j721e_pcie {
        struct device           *dev;
+       struct clk              *refclk;
        u32                     mode;
        u32                     num_lanes;
        struct cdns_pcie        *cdns_pcie;
@@ -312,6 +314,7 @@ static int j721e_pcie_probe(struct platform_device *pdev)
        struct cdns_pcie_ep *ep;
        struct gpio_desc *gpiod;
        void __iomem *base;
+       struct clk *clk;
        u32 num_lanes;
        u32 mode;
        int ret;
@@ -411,6 +414,20 @@ static int j721e_pcie_probe(struct platform_device *pdev)
                        goto err_get_sync;
                }
 
+               clk = devm_clk_get_optional(dev, "pcie_refclk");
+               if (IS_ERR(clk)) {
+                       ret = PTR_ERR(clk);
+                       dev_err(dev, "failed to get pcie_refclk\n");
+                       goto err_pcie_setup;
+               }
+
+               ret = clk_prepare_enable(clk);
+               if (ret) {
+                       dev_err(dev, "failed to enable pcie_refclk\n");
+                       goto err_get_sync;
+               }
+               pcie->refclk = clk;
+
                /*
                 * "Power Sequencing and Reset Signal Timings" table in
                 * PCI EXPRESS CARD ELECTROMECHANICAL SPECIFICATION, REV. 3.0
@@ -425,8 +442,10 @@ static int j721e_pcie_probe(struct platform_device *pdev)
                }
 
                ret = cdns_pcie_host_setup(rc);
-               if (ret < 0)
+               if (ret < 0) {
+                       clk_disable_unprepare(pcie->refclk);
                        goto err_pcie_setup;
+               }
 
                break;
        case PCI_MODE_EP:
@@ -479,6 +498,7 @@ static int j721e_pcie_remove(struct platform_device *pdev)
        struct cdns_pcie *cdns_pcie = pcie->cdns_pcie;
        struct device *dev = &pdev->dev;
 
+       clk_disable_unprepare(pcie->refclk);
        cdns_pcie_disable_phy(cdns_pcie);
        pm_runtime_put(dev);
        pm_runtime_disable(dev);