From: Heikki Krogerus <heikki.krogerus@linux.intel.com>
To: Badhri Jagan Sridharan <badhri@google.com>
Cc: Rob Herring <robh@kernel.org>,
Krzysztof Kozlowski <krzk+dt@kernel.org>,
Conor Dooley <conor+dt@kernel.org>,
Sebastian Reichel <sre@kernel.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Amit Sunil Dhamne <amitsd@google.com>,
devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-pm@vger.kernel.org, linux-usb@vger.kernel.org
Subject: Re: [PATCH v1 3/3] tcpm: Implement sink support for PD SPR AVS negotiation
Date: Mon, 2 Mar 2026 13:55:29 +0100 [thread overview]
Message-ID: <aaWIwQvxrAf-v5ec@black.igk.intel.com> (raw)
In-Reply-To: <20260226055311.2591357-4-badhri@google.com>
On Thu, Feb 26, 2026 at 05:53:11AM +0000, Badhri Jagan Sridharan wrote:
> Add support to enable TCPM to negotiate with
> USB PD Standard Power Range Adjustable Voltage Supply (SPR AVS) when
> acting as a power sink.
>
> * Added support to the tcpm power supply properties, allowing userspace
> to enable and control the dynamic limits (voltage and current)
> specific to the SPR AVS contract.
> * Implemented tcpm_pd_select_spr_avs_apdo() to select the appropriate
> APDO and validate the requested voltage/current against both the
> Source and Sink capabilities.
> * Implemented tcpm_pd_build_spr_avs_request() to construct the
> Request Data Object (RDO) for SPR AVS.
> * Added SNK_NEGOTIATE_SPR_AVS_CAPABILITIES state to the state machine to
> handle negotiation for SPR AVS.
> * Updated the SNK_TRANSITION_SINK state to implement the SPR
> AVS-specific VBUS transition rules, including reducing current draw to
> PD_I_SNK_STBY_MA for large voltage changes, as required by USB PD spec.
>
> Log stub captured when enabling AVS:
> $ echo 3 > /sys/class/power_supply/tcpm-source-psy-1-0025/online
> $ cat /d/usb/tcpm-1-0025/log
> [ 358.895775] request to set AVS online
> [ 358.895792] AMS POWER_NEGOTIATION start
> [ 358.895806] state change SNK_READY -> AMS_START [rev3 POWER_NEGOTIATION]
> [ 358.895850] state change AMS_START -> SNK_NEGOTIATE_SPR_AVS_CAPABILITIES [rev3 POWER_NEGOTIATION]
> [ 358.895866] SPR AVS src_pdo_index:4 snk_pdo_index:2 req_op_curr_ma roundup:2200 req_out_volt_mv roundup:9000
> [ 358.895880] Requesting APDO SPR AVS 4: 9000 mV, 2200 mA
> [ 358.896405] set_auto_vbus_discharge_threshold mode:0 pps_active:n vbus:0 pps_apdo_min_volt:0 ret:0
> [ 358.896422] PD TX, header: 0x1a82
> [ 358.900158] PD TX complete, status: 0
> [ 358.900205] pending state change SNK_NEGOTIATE_SPR_AVS_CAPABILITIES -> HARD_RESET_SEND @ 60 ms [rev3 POWER_NEGOTIATION]
> [ 358.904832] PD RX, header: 0x1a3 [1]
> [ 358.904854] state change SNK_NEGOTIATE_SPR_AVS_CAPABILITIES -> SNK_TRANSITION_SINK [rev3 POWER_NEGOTIATION]
> [ 358.904888] pending state change SNK_TRANSITION_SINK -> HARD_RESET_SEND @ 700 ms [rev3 POWER_NEGOTIATION]
> [ 359.021530] PD RX, header: 0x3a6 [1]
> [ 359.021546] Setting voltage/current limit 9000 mV 2200 mA
> [ 359.023035] set_auto_vbus_discharge_threshold mode:3 pps_active:n vbus:9000 pps_apdo_min_volt:0 ret:0
> [ 359.023053] state change SNK_TRANSITION_SINK -> SNK_READY [rev3 POWER_NEGOTIATION]
> [ 359.023090] AMS POWER_NEGOTIATION finished
>
> $ cat /sys/class/power_supply/tcpm-source-psy-1-0025/online
> 3
>
> Log stub captured when increasing voltage:
> $ echo 9100000 > /sys/class/power_supply/tcpm-source-psy-1-0025/voltage_now
> $ cat /d/usb/tcpm-1-0025/log
>
> [ 632.116714] AMS POWER_NEGOTIATION start
> [ 632.116728] state change SNK_READY -> AMS_START [rev3 POWER_NEGOTIATION]
> [ 632.116779] state change AMS_START -> SNK_NEGOTIATE_SPR_AVS_CAPABILITIES [rev3 POWER_NEGOTIATION]
> [ 632.116798] SPR AVS src_pdo_index:4 snk_pdo_index:2 req_op_curr_ma roundup:2200 req_out_volt_mv roundup:9100
> [ 632.116811] Requesting APDO SPR AVS 4: 9100 mV, 2200 mA
> [ 632.117315] set_auto_vbus_discharge_threshold mode:0 pps_active:n vbus:0 pps_apdo_min_volt:0 ret:0
> [ 632.117328] PD TX, header: 0x1c82
> [ 632.121007] PD TX complete, status: 0
> [ 632.121052] pending state change SNK_NEGOTIATE_SPR_AVS_CAPABILITIES -> HARD_RESET_SEND @ 60 ms [rev3 POWER_NEGOTIATION]
> [ 632.124572] PD RX, header: 0x5a3 [1]
> [ 632.124594] state change SNK_NEGOTIATE_SPR_AVS_CAPABILITIES -> SNK_TRANSITION_SINK [rev3 POWER_NEGOTIATION]
> [ 632.124623] pending state change SNK_TRANSITION_SINK -> HARD_RESET_SEND @ 700 ms [rev3 POWER_NEGOTIATION]
> [ 632.149256] PD RX, header: 0x7a6 [1]
> [ 632.149271] Setting voltage/current limit 9100 mV 2200 mA
> [ 632.150770] set_auto_vbus_discharge_threshold mode:3 pps_active:n vbus:9100 pps_apdo_min_volt:0 ret:0
> [ 632.150787] state change SNK_TRANSITION_SINK -> SNK_READY [rev3 POWER_NEGOTIATION]
> [ 632.150823] AMS POWER_NEGOTIATION finished
>
> $ cat /sys/class/power_supply/tcpm-source-psy-1-0025/voltage_now
> 9100000
>
> Signed-off-by: Badhri Jagan Sridharan <badhri@google.com>
> Reviewed-by: Amit Sunil Dhamne <amitsd@google.com>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
--
heikki
prev parent reply other threads:[~2026-03-02 12:55 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-26 5:53 [PATCH v1 0/3] Add support for AVS in TCPM Badhri Jagan Sridharan
2026-02-26 5:53 ` [PATCH v1 1/3] dt-bindings: connector: Add SPR AVS Sink APDO definitions Badhri Jagan Sridharan
2026-03-06 0:58 ` Rob Herring (Arm)
2026-02-26 5:53 ` [PATCH v1 2/3] power: supply: Add PD SPR AVS support to USB type enum Badhri Jagan Sridharan
2026-03-09 15:22 ` Sebastian Reichel
2026-03-16 22:34 ` Badhri Jagan Sridharan
2026-02-26 5:53 ` [PATCH v1 3/3] tcpm: Implement sink support for PD SPR AVS negotiation Badhri Jagan Sridharan
2026-03-02 12:55 ` Heikki Krogerus [this message]
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