[PATCH v4 2/3] phy: qcom: qmp-combo: get the USB3 & DisplayPort lanes mapping from DT

Dmitry Baryshkov dmitry.baryshkov at oss.qualcomm.com
Mon Oct 6 03:35:08 PDT 2025


On Mon, Oct 06, 2025 at 12:08:22PM +0200, Konrad Dybcio wrote:
> On 9/30/25 9:39 AM, Neil Armstrong wrote:
> > The QMP USB3/DP Combo PHY hosts an USB3 phy and a DP PHY on top
> > of a combo glue to route either lanes to the 4 shared physical lanes.
> > 
> > The routing of the lanes can be:
> > - 2 DP + 2 USB3
> > - 4 DP
> > - 2 USB3
> > 
> > Get the lanes mapping from DT and stop registering the USB-C
> > muxes in favor of a static mode and orientation detemined
> > by the lanes mapping.
> > 
> > This allows supporting boards with direct connection of USB3 and
> > DisplayPort lanes to the QMP Combo PHY lanes, not using the
> > USB-C Altmode feature.
> > 
> > Signed-off-by: Neil Armstrong <neil.armstrong at linaro.org>
> > ---
> 
> [...]
> 
> > +struct qmp_combo_lane_mapping {
> > +	unsigned int lanes_count;
> 
> "num_lanes"?
> 
> > +	enum typec_orientation orientation;
> > +	u32 lanes[4];
> > +};
> > +
> > +static const struct qmp_combo_lane_mapping usb3_data_lanes[] = {
> > +	{ 2, TYPEC_ORIENTATION_NORMAL, { 1, 0 }},
> > +	{ 2, TYPEC_ORIENTATION_REVERSE, { 2, 3 }},
> > +};
> > +
> > +static const struct qmp_combo_lane_mapping dp_data_lanes[] = {
> > +	{ 1, TYPEC_ORIENTATION_NORMAL, { 0 }},
> > +	{ 1, TYPEC_ORIENTATION_REVERSE, { 3 }},
> 
> This is not corroborated by your bindings change ^
> 
> I'm also frankly not sure whether it's pin 2 or 3 that 1-lane-DP
> would be TXd on

If we follow the standard, it should be 3 (RX2, TX2, TX1, RX1)

> 
> > +	{ 2, TYPEC_ORIENTATION_NORMAL, { 3, 2 }},
> > +	{ 2, TYPEC_ORIENTATION_REVERSE, { 0, 1 }},
> > +	{ 4, TYPEC_ORIENTATION_NORMAL, { 3, 2, 1, 0 }},
> > +	{ 4, TYPEC_ORIENTATION_REVERSE, { 0, 1, 2, 3 }},
> 
> Would it be too cheesy to check orientation based like:

That won't catch weird errors like {0, 2, 1, 3}.

> 
> static bool qmpphy_mapping_orient_flipped(u32 *data_lanes)
> {
> 	return data_lanes[0] == 0;
> }
> 
> ?
> 
> > -	ret = qmp_combo_typec_register(qmp);
> > -	if (ret)
> > -		goto err_node_put;
> > +	qmp->qmpphy_mode = QMPPHY_MODE_USB3DP;
> > +
> > +	if (of_find_property(dev->of_node, "mode-switch", NULL) ||
> > +	    of_find_property(dev->of_node, "orientation-switch", NULL)) {
> 
> of_property_present()
> 
> Konrad

-- 
With best wishes
Dmitry



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