usually, the reference clock comes from 26M oscillator directly,
but some SoCs are not, add it for compatibility.
Signed-off-by: Chunfeng Yun <chunfeng....@mediatek.com>
---
drivers/usb/host/xhci-mtk.c | 22 ++++++++++++++++++++++
drivers/usb/host/xhci-mtk.h | 1 +
2 files changed, 23 insertions(+)
diff --git a/drivers/usb/host/xhci-mtk.c b/drivers/usb/host/xhci-mtk.c
index 1094ebd..75bae8e 100644
--- 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 @@ static int xhci_mtk_clks_enable(struct xhci_hcd_mtk *mtk)
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 +559,19 @@ 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)) {
+ 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");
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
--- 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;
--
1.7.9.5
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