[PATCH -next 3/3] usb: xhci-mtk: make the reference clock optional

From: Chunfeng Yun
Date: Tue Feb 07 2017 - 01:14:39 EST


Make the reference clock optional for DTS backward compatibility
and ignore the error if it does not exist.

Signed-off-by: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx>
---
drivers/usb/host/xhci-mtk.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/host/xhci-mtk.c b/drivers/usb/host/xhci-mtk.c
index 4d75ac5..75bae8e 100644
--- a/drivers/usb/host/xhci-mtk.c
+++ b/drivers/usb/host/xhci-mtk.c
@@ -559,10 +559,17 @@ static int xhci_mtk_probe(struct platform_device *pdev)
return PTR_ERR(mtk->sys_clk);
}

+ /*
+ * reference clock is usually a "fixed-clock", make it optional
+ * for backward compatibility and ignore the error if it does
+ * not exist.
+ */
mtk->ref_clk = devm_clk_get(dev, "ref_ck");
if (IS_ERR(mtk->ref_clk)) {
- dev_err(dev, "fail to get ref_ck\n");
- return PTR_ERR(mtk->ref_clk);
+ if (PTR_ERR(mtk->ref_clk) == -EPROBE_DEFER)
+ return -EPROBE_DEFER;
+
+ mtk->ref_clk = NULL;
}

mtk->lpm_support = of_property_read_bool(node, "usb3-lpm-capable");
--
1.7.9.5