[PATCH v2 4/4] PCI: j721e: Add support to provide refclk to PCIe connector

Kishon Vijay Abraham I
2021-01-04T12:43:08Z

Add support to provide refclk to PCIe connector.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
---
drivers/pci/controller/cadence/pci-j721e.c | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)

diff --git a/drivers/pci/controller/cadence/pci-j721e.c b/drivers/pci/controller/cadence/pci-j721e.c
index dac1ac8a7615..2e73729c7388 100644
--- 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;
@@ -310,6 +312,7 @@ 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;
@@ -408,6 +411,20 @@ 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)) {
+ dev_err(dev, "failed to get pcie_refclk\n");
+ ret = PTR_ERR(clk);
+ 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
@@ -476,6 +493,7 @@ 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);
--
2.17.1