[PATCH 3/6] usb: xhci-mtk: add reference clock

From: Chunfeng Yun
Date: Wed Jan 18 2017 - 01:10:04 EST


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@xxxxxxxxxxxx>
---
drivers/usb/host/xhci-mtk.c | 15 +++++++++++++++
drivers/usb/host/xhci-mtk.h | 1 +
2 files changed, 16 insertions(+)

diff --git a/drivers/usb/host/xhci-mtk.c b/drivers/usb/host/xhci-mtk.c
index 1094ebd..4d75ac5 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 +559,12 @@ 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
--- 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