Re: [PATCH v3 2/3] phy: qcom-qmp-combo: Add config for SM6350

["Luca Weiss" <luca.weiss@fairphone.com>]

Hi Johan,

On Wed Dec 28, 2022 at 3:17 PM CET, Johan Hovold wrote:
> Luca, Vinod,
>
> On Wed, Nov 30, 2022 at 09:14:28AM +0100, Luca Weiss wrote:
> > Add the tables and config for the combo phy found on SM6350.
> > 
> > Signed-off-by: Luca Weiss <luca.weiss@fairphone.com>
> > ---
> > Changes since v2:
> > * Drop dp_txa/dp_txb changes, not required
> > * Fix dp_dp_phy offset
> > 
> >  drivers/phy/qualcomm/phy-qcom-qmp-combo.c | 126 ++++++++++++++++++++++
> >  1 file changed, 126 insertions(+)
> > 
> > diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-combo.c b/drivers/phy/qualcomm/phy-qcom-qmp-combo.c
> > index 77052c66cf70..6ac0c68269dc 100644
> > --- a/drivers/phy/qualcomm/phy-qcom-qmp-combo.c
> > +++ b/drivers/phy/qualcomm/phy-qcom-qmp-combo.c
>
> > @@ -975,6 +1039,19 @@ static const char * const sc7180_usb3phy_reset_l[] = {
> >  	"phy",
> >  };
> >  
> > +static const struct qmp_combo_offsets qmp_combo_offsets_v3 = {
> > +	.com		= 0x0000,
> > +	.txa		= 0x1200,
> > +	.rxa		= 0x1400,
> > +	.txb		= 0x1600,
> > +	.rxb		= 0x1800,
> > +	.usb3_serdes	= 0x1000,
> > +	.usb3_pcs_misc	= 0x1a00,
> > +	.usb3_pcs	= 0x1c00,
> > +	.dp_serdes	= 0x1000,
>
> I would have expected this to be 0x2000 as that's what the older
> platforms have been using for the dp serdes table so far. Without access
> to any documentation it's hard to tell whether everyone's just been
> cargo-culting all along or if there's actually something there at offset
> 0x2000.

From what I saw comparing downstream code vs mainline 0x1000 should be
correct.

From https://gerrit-public.fairphone.software/plugins/gitiles/kernel/msm-4.19/+/refs/heads/kernel/11/fp4/include/dt-bindings/phy/qcom,lagoon-qmp-usb3.h#38

USB3_DP_QSERDES_COM_BIAS_EN_CLKBUFLR_EN (downstream 0x1034) =
  QSERDES_V3_COM_BIAS_EN_CLKBUFLR_EN (mainline 0x034)

USB3_DP_QSERDES_COM_CP_CTRL_MODE0 (downstream 0x1060) =
  QSERDES_V3_COM_CP_CTRL_MODE0 (mainline 0x060)

These defines downstream are used in qcom,qmp-phy-init-seq
(lagoon-usb.dtsi) which super abbreviated gets used like this:

lagoon-usb.dtsi:
    reg = <0x88e8000 0x3000>;
    reg-names = "qmp_phy_base";
    qcom,qmp-phy-init-seq = <...>;

drivers/usb/phy/phy-msm-ssusb-qmp.c
    res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
                        "qmp_phy_base");
    phy->base = devm_ioremap_nocache(dev, res->start, resource_size(res));

    of_property_read_u32_array(dev->of_node,
            "qcom,qmp-phy-init-seq",
            phy->qmp_phy_init_seq,
            phy->init_seq_len);

    reg = (struct qmp_reg_val *)phy->qmp_phy_init_seq;

    while (reg->offset != -1) {
        writel_relaxed(reg->val, phy->base + reg->offset);

I don't see anywhere where an extra 0x1000 should come from. But perhaps
I'm missing something. The reg address is the same downstream and
mainline also.

>
> Vinod, could you shed some light on this as presumably you have access
> to some documentation?

That would be useful :)

Regards
Luca

>
> > +	.dp_dp_phy	= 0x2a00,
> > +};
>
> Johan