linux-kernel - Re: [PATCH v1 3/3] usb: typec: ucsi: Get PD revision for partner

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Date: Wed, 24 Jan 2024 10:48:57 -0800
From: Prashant Malani <pmalani@...omium.org>
To: Abhishek Pandit-Subedi <abhishekpandit@...gle.com>
Cc: Heikki Krogerus <heikki.krogerus@...ux.intel.com>, linux-usb@...r.kernel.org, 
	jthies@...gle.com, Abhishek Pandit-Subedi <abhishekpandit@...omium.org>, 
	Andy Shevchenko <andriy.shevchenko@...ux.intel.com>, Bjorn Andersson <andersson@...nel.org>, 
	Dmitry Baryshkov <dmitry.baryshkov@...aro.org>, Fabrice Gasnier <fabrice.gasnier@...s.st.com>, 
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>, Hans de Goede <hdegoede@...hat.com>, 
	Neil Armstrong <neil.armstrong@...aro.org>, Saranya Gopal <saranya.gopal@...el.com>, 
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH v1 3/3] usb: typec: ucsi: Get PD revision for partner

Hi Abhishek,

On Tue, Jan 23, 2024 at 2:30 PM Abhishek Pandit-Subedi
<abhishekpandit@...gle.com> wrote:
>
> From: Abhishek Pandit-Subedi <abhishekpandit@...omium.org>
>
> PD major revision for the port partner is described in
> GET_CONNECTOR_CAPABILITY and is only valid on UCSI 2.0 and newer. Update
> the pd_revision on the partner if the UCSI version is 2.0 or newer.
>
> Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@...omium.org>
> ---
> $ cat /sys/class/typec/port2-partner/usb_power_delivery_revision
> 3.0
>
>  drivers/usb/typec/ucsi/ucsi.c | 25 +++++++++++++++++++++++++
>  drivers/usb/typec/ucsi/ucsi.h |  3 +++
>  2 files changed, 28 insertions(+)
>
> diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
> index 4edf785d203b..8e0a512853ba 100644
> --- a/drivers/usb/typec/ucsi/ucsi.c
> +++ b/drivers/usb/typec/ucsi/ucsi.c
> @@ -782,6 +782,8 @@ static int ucsi_register_partner(struct ucsi_connector *con)
>         }
>
>         desc.usb_pd = pwr_opmode == UCSI_CONSTAT_PWR_OPMODE_PD;
> +       desc.pd_revision =
> +               UCSI_CONCAP_FLAG_PARTNER_PD_MAJOR_REV_AS_BCD(con->cap.flags);
>
>         partner = typec_register_partner(con->port, &desc);
>         if (IS_ERR(partner)) {
> @@ -856,6 +858,28 @@ static void ucsi_partner_change(struct ucsi_connector *con)
>                         con->num, u_role);
>  }
>
> +static int ucsi_check_connector_capability(struct ucsi_connector *con)
> +{
> +       u64 command;
> +       int ret;
> +
> +       if (!con->partner && !IS_MIN_VERSION_2_0(con->ucsi))

(Mentioned side-band but reproducing here for consistency)
This macro is unnecessary. It's just doing a comparison, which can be inlined
without any perceptible change in readability (actually, I'd argue adding the !
to an english idiom makes things *less* readable):

        if (!con->partner && con->ucsi->version < UCSI_VERSION_2_0)
               return 0;

Besides that, I think you want an || operator instead of the && operator, right?

> +               return 0;
> +
> +       command = UCSI_GET_CONNECTOR_CAPABILITY | UCSI_CONNECTOR_NUMBER(con->num);
> +       ret = ucsi_send_command(con->ucsi, command, &con->cap, sizeof(con->cap));
> +       if (ret < 0) {
> +               dev_err(con->ucsi->dev, "GET_CONNECTOR_CAPABILITY failed (%d)\n", ret);
> +               return ret;
> +       }
> +
> +       typec_partner_set_pd_revision(
> +               con->partner,
> +               UCSI_CONCAP_FLAG_PARTNER_PD_MAJOR_REV_AS_BCD(con->cap.flags));
> +
> +       return ret;
> +}
> +
>  static int ucsi_check_connection(struct ucsi_connector *con)
>  {
>         u8 prev_flags = con->status.flags;

Thanks,