usb: xhci-mtk: add reference clock

usually, the reference clock comes from 26M oscillator directly,
but some SoCs are not, add it for compatibility.

Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/host/xhci-mtk.c b/drivers/usb/host/xhci-mtk.c
index bac961c..b30806a 100644 (file)
--- a/drivers/usb/host/xhci-mtk.c
+++ b/drivers/usb/host/xhci-mtk.c
@@ -212,6 +212,12 @@ static int xhci_mtk_clks_enable(struct xhci_hcd_mtk *mtk)
 {
        int ret;
 
+       ret = clk_prepare_enable(mtk->ref_clk);
+       if (ret) {
+               dev_err(mtk->dev, "failed to enable ref_clk\n");
+               goto ref_clk_err;
+       }
+
        ret = clk_prepare_enable(mtk->sys_clk);
        if (ret) {
                dev_err(mtk->dev, "failed to enable sys_clk\n");
@@ -238,6 +244,8 @@ usb_p1_err:
 usb_p0_err:
        clk_disable_unprepare(mtk->sys_clk);
 sys_clk_err:
+       clk_disable_unprepare(mtk->ref_clk);
+ref_clk_err:
        return -EINVAL;
 }
 
@@ -248,6 +256,7 @@ static void xhci_mtk_clks_disable(struct xhci_hcd_mtk *mtk)
                clk_disable_unprepare(mtk->wk_deb_p0);
        }
        clk_disable_unprepare(mtk->sys_clk);
+       clk_disable_unprepare(mtk->ref_clk);
 }
 
 /* only clocks can be turn off for ip-sleep wakeup mode */
@@ -550,6 +559,12 @@ static int xhci_mtk_probe(struct platform_device *pdev)
                return PTR_ERR(mtk->sys_clk);
        }
 
+       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);
+       }
+
        mtk->lpm_support = of_property_read_bool(node, "usb3-lpm-capable");
 
        ret = usb_wakeup_of_property_parse(mtk, node);

diff --git a/drivers/usb/host/xhci-mtk.h b/drivers/usb/host/xhci-mtk.h
index 2845c49..3aa5e1d 100644 (file)
--- a/drivers/usb/host/xhci-mtk.h
+++ b/drivers/usb/host/xhci-mtk.h
@@ -124,6 +124,7 @@ struct xhci_hcd_mtk {
        struct regulator *vusb33;
        struct regulator *vbus;
        struct clk *sys_clk;    /* sys and mac clock */
+       struct clk *ref_clk;
        struct clk *wk_deb_p0;  /* port0's wakeup debounce clock */
        struct clk *wk_deb_p1;
        struct regmap *pericfg;