Re: [RFC v3 5/7] phy: qcom: phy-qcom-snps-eusb2: Add support for eUSB2 repeater

From: Abel Vesa
Date: Tue Feb 07 2023 - 02:11:18 EST


On 23-02-03 19:19:22, Vinod Koul wrote:
> On 02-02-23, 15:38, Abel Vesa wrote:
> > From: Neil Armstrong <neil.armstrong@xxxxxxxxxx>
> >
> > For USB 2.0 compliance, eUSB2 needs a repeater. The PHY needs to
> > initialize and reset it. So add repeater support
> >
> > Co-developed-by: Abel Vesa <abel.vesa@xxxxxxxxxx>
> > Signed-off-by: Abel Vesa <abel.vesa@xxxxxxxxxx>
> > Signed-off-by: Neil Armstrong <neil.armstrong@xxxxxxxxxx>
> > ---
> > drivers/phy/qualcomm/phy-qcom-snps-eusb2.c | 18 +++++++++++++++++-
> > 1 file changed, 17 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/phy/qualcomm/phy-qcom-snps-eusb2.c b/drivers/phy/qualcomm/phy-qcom-snps-eusb2.c
> > index 23ec162cc3bd..8d972d49732b 100644
> > --- a/drivers/phy/qualcomm/phy-qcom-snps-eusb2.c
> > +++ b/drivers/phy/qualcomm/phy-qcom-snps-eusb2.c
> > @@ -128,6 +128,8 @@ struct qcom_snps_eusb2_hsphy {
> > struct regulator_bulk_data vregs[EUSB2_NUM_VREGS];
> >
> > enum phy_mode mode;
> > +
> > + struct phy *repeater;
> > };
> >
> > static int qcom_snps_eusb2_hsphy_set_mode(struct phy *p, enum phy_mode mode, int submode)
> > @@ -136,7 +138,7 @@ static int qcom_snps_eusb2_hsphy_set_mode(struct phy *p, enum phy_mode mode, int
> >
> > phy->mode = mode;
> >
> > - return 0;
> > + return phy_set_mode_ext(phy->repeater, mode, submode);
> > }
> >
> > static void qcom_snps_eusb2_hsphy_write_mask(void __iomem *base, u32 offset,
> > @@ -235,6 +237,12 @@ static int qcom_snps_eusb2_hsphy_init(struct phy *p)
> > if (ret)
> > return ret;
> >
> > + ret = phy_init(phy->repeater);
> > + if (ret) {
> > + dev_err(&p->dev, "repeater init failed. %d\n", ret);
> > + goto disable_vreg;
> > + }
> > +
> > ret = clk_prepare_enable(phy->ref_clk);
> > if (ret) {
> > dev_err(&p->dev, "failed to enable ref clock, %d\n", ret);
> > @@ -342,6 +350,8 @@ static int qcom_snps_eusb2_hsphy_exit(struct phy *p)
> >
> > regulator_bulk_disable(ARRAY_SIZE(phy->vregs), phy->vregs);
> >
> > + phy_exit(phy->repeater);
> > +
> > return 0;
> > }
> >
> > @@ -386,6 +396,12 @@ static int qcom_snps_eusb2_hsphy_probe(struct platform_device *pdev)
> > if (ret)
> > return dev_err_probe(dev, ret,
> > "failed to get regulator supplies\n");
> > +
> > + phy->repeater = devm_phy_get(dev, "eusb2-repeater");
> > + if (IS_ERR(phy->repeater))
> > + return dev_err_probe(dev, PTR_ERR(phy->repeater),
> > + "failed to get repeater\n");
>
> That implies repeater is assumed to be there for all designs, how about
> older devices, they may not have a repeater?

Well, no other (older) platform has eUSB2 support, IIRC.

And the eUSB2 can't be used as USB 2.0 without the repeater.

>
> > +
> > generic_phy = devm_phy_create(dev, NULL, &qcom_snps_eusb2_hsphy_ops);
> > if (IS_ERR(generic_phy)) {
> > dev_err(dev, "failed to create phy %d\n", ret);
> > --
> > 2.34.1
>
> --
> ~Vinod