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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <74446713-15a1-4706-b3c7-801724467575@oss.qualcomm.com>
Date: Mon, 6 Oct 2025 12:08:22 +0200
From: Konrad Dybcio <konrad.dybcio@....qualcomm.com>
To: Neil Armstrong <neil.armstrong@...aro.org>, Vinod Koul
 <vkoul@...nel.org>,
        Kishon Vijay Abraham I <kishon@...nel.org>,
        Rob Herring <robh@...nel.org>,
        Krzysztof Kozlowski <krzk+dt@...nel.org>,
        Conor Dooley <conor+dt@...nel.org>,
        Bjorn Andersson <andersson@...nel.org>,
        Konrad Dybcio <konradybcio@...nel.org>
Cc: Xilin Wu <sophon@...xa.com>, linux-arm-msm@...r.kernel.org,
        linux-phy@...ts.infradead.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v4 2/3] phy: qcom: qmp-combo: get the USB3 & DisplayPort
 lanes mapping from DT

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@...aro.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

> +	{ 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:

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