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Message-ID: <CAPTae5+sAAj+j1Ob=Xy93rbs21SiSkKm0gHLmF0kxue_HoOGuQ@mail.gmail.com>
Date: Tue, 14 Oct 2025 21:11:22 -0700
From: Badhri Jagan Sridharan <badhri@...gle.com>
To: heikki.krogerus@...ux.intel.com, gregkh@...uxfoundation.org, 
	badhri@...gle.com
Cc: amitsd@...gle.com, kyletso@...gle.com, rdbabiera@...gle.com, 
	linux-kernel@...r.kernel.org, linux-usb@...r.kernel.org
Subject: Re: [PATCH v1 2/2] usb: typec: pd: Register SPR AVS caps with
 usb_power_delivery class

On Tue, Oct 14, 2025 at 9:06 PM Badhri Jagan Sridharan
<badhri@...gle.com> wrote:
>
> usb_power_delivery class will now display AVS cap as
> `spr_adjustable_voltage_supply`. `maximum_current_9V_to_15V` and
> `maximum_current_15V_to_20V` shows the corresponding current limits
> in mA. `peak_current` follows the same convention as fixed_supply
> where the value reported in the capabilities message is displayed
> as is.
>
> Sample output with an SPR AVS capable PD charger:
> $cat /sys/class/usb_power_delivery/pd1/source-capabilities/5:spr_adjustable_voltage_supply/maximum_current_9V_to_15V
> 4000mA
>
> $cat /sys/class/usb_power_delivery/pd1/source-capabilities/5:spr_adjustable_voltage_supply/maximum_current_15V_to_20V
> 3350mA
>
> $cat /sys/class/usb_power_delivery/pd1/source-capabilities/5:spr_adjustable_voltage_supply/peak_current
> 0
>
> Signed-off-by: Badhri Jagan Sridharan <badhri@...gle.com>
> ---
>  .../testing/sysfs-class-usb_power_delivery    | 28 ++++++
>  drivers/usb/typec/pd.c                        | 95 ++++++++++++++++++-
>  drivers/usb/typec/tcpm/tcpm.c                 |  2 +-
>  3 files changed, 119 insertions(+), 6 deletions(-)
>
> diff --git a/Documentation/ABI/testing/sysfs-class-usb_power_delivery b/Documentation/ABI/testing/sysfs-class-usb_power_delivery
> index 61d233c320ea..c754458a527e 100644
> --- a/Documentation/ABI/testing/sysfs-class-usb_power_delivery
> +++ b/Documentation/ABI/testing/sysfs-class-usb_power_delivery
> @@ -254,3 +254,31 @@ Contact:   Heikki Krogerus <heikki.krogerus@...ux.intel.com>
>  Description:
>                 The PPS Power Limited bit indicates whether or not the source
>                 supply will exceed the rated output power if requested.
> +
> +Standard Power Range (SPR) Adjustable Voltage Supplies
> +
> +What:          /sys/class/usb_power_delivery/.../<capability>/<position>:spr_adjustable_voltage_supply
> +Date:          Oct 2025
> +Contact:       Badhri Jagan Sridharan <badhri@...gle.com>
> +Description:
> +               Adjustable Voltage Supply (AVS) Augmented PDO (APDO).
> +
> +What:          /sys/class/usb_power_delivery/.../<capability>/<position>:spr_adjustable_voltage_supply/maximum_current_9V_to_15V
> +Date:          Oct 2025
> +Contact:       Badhri Jagan Sridharan <badhri@...gle.com>
> +Description:
> +               Maximum Current for 9V to 15V range in milliamperes.
> +
> +What:          /sys/class/usb_power_delivery/.../<capability>/<position>:spr_adjustable_voltage_supply/maximum_current_15V_to_20V
> +Date:          Oct 2025
> +Contact:       Badhri Jagan Sridharan <badhri@...gle.com>
> +Description:
> +               Maximum Current for greater than 15V till 20V range in
> +               milliamperes.
> +
> +What:          /sys/class/usb_power_delivery/.../<capability>/<position>:spr_adjustable_voltage_supply/peak_current
> +Date:          Oct 2025
> +Contact:       Badhri Jagan Sridharan <badhri@...gle.com>
> +Description:
> +               This file shows the value of the Adjustable Voltage Supply Peak Current
> +               Capability field.
> diff --git a/drivers/usb/typec/pd.c b/drivers/usb/typec/pd.c
> index d78c04a421bc..67f20b5ffdf4 100644
> --- a/drivers/usb/typec/pd.c
> +++ b/drivers/usb/typec/pd.c
> @@ -359,6 +359,84 @@ static const struct device_type sink_pps_type = {
>         .groups = sink_pps_groups,
>  };
>
> +/* -------------------------------------------------------------------------- */
> +/* Standard Power Range (SPR) Adjustable Voltage Supply (AVS) */
> +
> +static ssize_t
> +spr_avs_9v_to_15v_max_current_show(struct device *dev,
> +                                  struct device_attribute *attr, char *buf)
> +{
> +       return sysfs_emit(buf, "%umA\n",
> +                         pdo_spr_avs_apdo_9v_to_15v_max_current_ma(to_pdo(dev)->pdo));
> +}
> +
> +static ssize_t
> +spr_avs_15v_to_20v_max_current_show(struct device *dev,
> +                                   struct device_attribute *attr, char *buf)
> +{
> +       return sysfs_emit(buf, "%umA\n",
> +                         pdo_spr_avs_apdo_15v_to_20v_max_current_ma(to_pdo(dev)->pdo));
> +}
> +
> +static ssize_t
> +spr_avs_src_peak_current_show(struct device *dev,
> +                             struct device_attribute *attr, char *buf)
> +{
> +       return sysfs_emit(buf, "%u\n",
> +                         pdo_spr_avs_apdo_src_peak_current(to_pdo(dev)->pdo));
> +}
> +
> +static struct device_attribute spr_avs_9v_to_15v_max_current_attr = {
> +       .attr = {
> +               .name = "maximum_current_9V_to_15V",
> +               .mode = 0444,
> +       },
> +       .show = spr_avs_9v_to_15v_max_current_show,
> +};
> +
> +static struct device_attribute spr_avs_15v_to_20v_max_current_attr = {
> +       .attr = {
> +               .name = "maximum_current_15V_to_20V",
> +               .mode = 0444,
> +       },
> +       .show = spr_avs_15v_to_20v_max_current_show,
> +};
> +
> +static struct device_attribute spr_avs_src_peak_current_attr = {
> +       .attr = {
> +               .name = "peak_current",
> +               .mode = 0444,
> +       },
> +       .show = spr_avs_src_peak_current_show,
> +};
> +
> +static struct attribute *source_spr_avs_attrs[] = {
> +       &spr_avs_9v_to_15v_max_current_attr.attr,
> +       &spr_avs_15v_to_20v_max_current_attr.attr,
> +       &spr_avs_src_peak_current_attr.attr,
> +       NULL
> +};
> +ATTRIBUTE_GROUPS(source_spr_avs);
> +
> +static const struct device_type source_spr_avs_type = {
> +       .name = "pdo",
> +       .release = pdo_release,
> +       .groups = source_spr_avs_groups,
> +};
> +
> +static struct attribute *sink_spr_avs_attrs[] = {
> +       &spr_avs_9v_to_15v_max_current_attr.attr,
> +       &spr_avs_15v_to_20v_max_current_attr.attr,
> +       NULL
> +};
> +ATTRIBUTE_GROUPS(sink_spr_avs);
> +
> +static const struct device_type sink_spr_avs_type = {
> +       .name = "pdo",
> +       .release = pdo_release,
> +       .groups = sink_spr_avs_groups,
> +};
> +
>  /* -------------------------------------------------------------------------- */
>
>  static const char * const supply_name[] = {
> @@ -368,7 +446,8 @@ static const char * const supply_name[] = {
>  };
>
>  static const char * const apdo_supply_name[] = {
> -       [APDO_TYPE_PPS]  = "programmable_supply",
> +       [APDO_TYPE_PPS]      = "programmable_supply",
> +       [APDO_TYPE_SPR_AVS]  = "spr_adjustable_voltage_supply",
>  };
>
>  static const struct device_type *source_type[] = {
> @@ -378,7 +457,8 @@ static const struct device_type *source_type[] = {
>  };
>
>  static const struct device_type *source_apdo_type[] = {
> -       [APDO_TYPE_PPS]  = &source_pps_type,
> +       [APDO_TYPE_PPS]     = &source_pps_type,
> +       [APDO_TYPE_SPR_AVS] = &source_spr_avs_type,
>  };
>
>  static const struct device_type *sink_type[] = {
> @@ -388,7 +468,8 @@ static const struct device_type *sink_type[] = {
>  };
>
>  static const struct device_type *sink_apdo_type[] = {
> -       [APDO_TYPE_PPS]  = &sink_pps_type,
> +       [APDO_TYPE_PPS]     = &sink_pps_type,
> +       [APDO_TYPE_SPR_AVS] = &sink_spr_avs_type,
>  };
>
>  /* REVISIT: Export when EPR_*_Capabilities need to be supported. */
> @@ -407,8 +488,12 @@ static int add_pdo(struct usb_power_delivery_capabilities *cap, u32 pdo, int pos
>         p->object_position = position;
>
>         if (pdo_type(pdo) == PDO_TYPE_APDO) {
> -               /* FIXME: Only PPS supported for now! Skipping others. */
> -               if (pdo_apdo_type(pdo) > APDO_TYPE_PPS) {
> +               /*
> +                * FIXME: Only PPS, SPR_AVS supported for now!
> +                * Skipping others.
> +                */
> +               if (pdo_apdo_type(pdo) != APDO_TYPE_PPS &&
> +                   pdo_apdo_type(pdo) != APDO_TYPE_SPR_AVS) {
>                         dev_warn(&cap->dev, "Unknown APDO type. PDO 0x%08x\n", pdo);
>                         kfree(p);
>                         return 0;
> diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
> index 6e6c27df3c2e..c65aa8104950 100644
> --- a/drivers/usb/typec/tcpm/tcpm.c
> +++ b/drivers/usb/typec/tcpm/tcpm.c
> @@ -831,7 +831,7 @@ static void tcpm_log_source_caps(struct tcpm_port *port)
>                                 scnprintf(msg, sizeof(msg),
>                                           "EPR AVS %u-%u mV %u W peak_current: %u",
>                                           pdo_epr_avs_apdo_min_voltage_mv(pdo),
> -                                         pdo_epr_avs_apdo_min_voltage_mv(pdo),
> +                                         pdo_epr_avs_apdo_max_voltage_mv(pdo),

Hi all,

Apologies, kindly disregard the v1. I incorrectly squashed a fix.
Sending out v2.

Regards,
Badhri

>                                           pdo_epr_avs_apdo_pdp_w(pdo),
>                                           pdo_epr_avs_apdo_src_peak_current(pdo));
>                         else if (pdo_apdo_type(pdo) == APDO_TYPE_SPR_AVS)
> --
> 2.51.0.858.gf9c4a03a3a-goog
>

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