On Thu, 2017-01-19 at 13:22 +0100, Matthias Brugger wrote:
>
> On 18/01/17 07:08, Chunfeng Yun wrote:
> > 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/mtu3/mtu3.h | 1 +
> > drivers/usb/mtu3/mtu3_plat.c | 21 +++++++++++++++++++--
> > 2 files changed, 20 insertions(+), 2 deletions(-)
[...]
> > @@ -154,6 +162,7 @@ static int ssusb_rscs_init(struct ssusb_mtk *ssusb)
> > static void ssusb_rscs_exit(struct ssusb_mtk *ssusb)
> > {
> > clk_disable_unprepare(ssusb->sys_clk);
> > + clk_disable_unprepare(ssusb->ref_clk);
> > regulator_disable(ssusb->vusb33);
> > ssusb_phy_power_off(ssusb);
> > ssusb_phy_exit(ssusb);
> > @@ -216,6 +225,12 @@ static int get_ssusb_rscs(struct platform_device *pdev, struct ssusb_mtk *ssusb)
> > return PTR_ERR(ssusb->sys_clk);
> > }
> >
> > + ssusb->ref_clk = devm_clk_get(dev, "ref_ck");
> > + if (IS_ERR(ssusb->ref_clk)) {
> > + dev_err(dev, "failed to get ref clock\n");
> > + return PTR_ERR(ssusb->ref_clk);
> > + }
> > +
>
> That would break older dts bindings, right?
Yes, So I send a new patch for the related dts. Maybe it's not a
problem, only one dts file need be updated currently.
> ref_ck must be optional for the code.
I tend to make it be optional for the dts, but not for the code.
There are some "fixed-clock" which can be treated as dummy ones, and if
a clock is really optional, we can use one fixed-clock in dts, and keep
the code simple.
In fact, the reference clock is essential for usb controller.
>
> Regards,
> Matthias
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
