Re: [PATCH] usb: typec: tcpm: Support non-PD mode

[Kyle Tso <kyletso@google.com>]

On Fri, Jul 16, 2021 at 5:39 PM Kyle Tso <kyletso@google.com> wrote:
>
> tcpm.c could work well without PD capabilities. Do not block the probe
> if capabilities are not defined in fwnode and skip the PD power
> negotiation in the state machine.
>
> Signed-off-by: Kyle Tso <kyletso@google.com>
> ---

Hi, any comments about this patch?

thanks,
Kyle

>  drivers/usb/typec/tcpm/tcpm.c | 50 ++++++++++++++++++++---------------
>  1 file changed, 29 insertions(+), 21 deletions(-)
>
> diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
> index 5b22a1c931a9..a42de5e17d24 100644
> --- a/drivers/usb/typec/tcpm/tcpm.c
> +++ b/drivers/usb/typec/tcpm/tcpm.c
> @@ -3914,6 +3914,8 @@ static void run_state_machine(struct tcpm_port *port)
>                 if (port->ams == POWER_ROLE_SWAP ||
>                     port->ams == FAST_ROLE_SWAP)
>                         tcpm_ams_finish(port);
> +               if (!port->nr_src_pdo)
> +                       tcpm_set_state(port, SRC_READY, 0);
>                 port->upcoming_state = SRC_SEND_CAPABILITIES;
>                 tcpm_ams_start(port, POWER_NEGOTIATION);
>                 break;
> @@ -4161,7 +4163,10 @@ static void run_state_machine(struct tcpm_port *port)
>                                 current_lim = PD_P_SNK_STDBY_MW / 5;
>                         tcpm_set_current_limit(port, current_lim, 5000);
>                         tcpm_set_charge(port, true);
> -                       tcpm_set_state(port, SNK_WAIT_CAPABILITIES, 0);
> +                       if (!port->nr_snk_pdo)
> +                               tcpm_set_state(port, SNK_READY, 0);
> +                       else
> +                               tcpm_set_state(port, SNK_WAIT_CAPABILITIES, 0);
>                         break;
>                 }
>                 /*
> @@ -5939,15 +5944,17 @@ static int tcpm_fw_get_caps(struct tcpm_port *port,
>
>         /* Get source pdos */
>         ret = fwnode_property_count_u32(fwnode, "source-pdos");
> -       if (ret <= 0)
> -               return -EINVAL;
> +       if (ret < 0)
> +               ret = 0;
>
>         port->nr_src_pdo = min(ret, PDO_MAX_OBJECTS);
> -       ret = fwnode_property_read_u32_array(fwnode, "source-pdos",
> -                                            port->src_pdo, port->nr_src_pdo);
> -       if ((ret < 0) || tcpm_validate_caps(port, port->src_pdo,
> -                                           port->nr_src_pdo))
> -               return -EINVAL;
> +       if (port->nr_src_pdo) {
> +               ret = fwnode_property_read_u32_array(fwnode, "source-pdos",
> +                                                    port->src_pdo, port->nr_src_pdo);
> +               if ((ret < 0) || tcpm_validate_caps(port, port->src_pdo,
> +                                                   port->nr_src_pdo))
> +                       return -EINVAL;
> +       }
>
>         if (port->port_type == TYPEC_PORT_SRC)
>                 return 0;
> @@ -5963,19 +5970,21 @@ static int tcpm_fw_get_caps(struct tcpm_port *port,
>  sink:
>         /* Get sink pdos */
>         ret = fwnode_property_count_u32(fwnode, "sink-pdos");
> -       if (ret <= 0)
> -               return -EINVAL;
> +       if (ret < 0)
> +               ret = 0;
>
>         port->nr_snk_pdo = min(ret, PDO_MAX_OBJECTS);
> -       ret = fwnode_property_read_u32_array(fwnode, "sink-pdos",
> -                                            port->snk_pdo, port->nr_snk_pdo);
> -       if ((ret < 0) || tcpm_validate_caps(port, port->snk_pdo,
> -                                           port->nr_snk_pdo))
> -               return -EINVAL;
> +       if (port->nr_snk_pdo) {
> +               ret = fwnode_property_read_u32_array(fwnode, "sink-pdos",
> +                                                    port->snk_pdo, port->nr_snk_pdo);
> +               if ((ret < 0) || tcpm_validate_caps(port, port->snk_pdo,
> +                                                   port->nr_snk_pdo))
> +                       return -EINVAL;
>
> -       if (fwnode_property_read_u32(fwnode, "op-sink-microwatt", &mw) < 0)
> -               return -EINVAL;
> -       port->operating_snk_mw = mw / 1000;
> +               if (fwnode_property_read_u32(fwnode, "op-sink-microwatt", &mw) < 0)
> +                       return -EINVAL;
> +               port->operating_snk_mw = mw / 1000;
> +       }
>
>         port->self_powered = fwnode_property_read_bool(fwnode, "self-powered");
>
> @@ -6283,9 +6292,8 @@ struct tcpm_port *tcpm_register_port(struct device *dev, struct tcpc_dev *tcpc)
>         int err;
>
>         if (!dev || !tcpc ||
> -           !tcpc->get_vbus || !tcpc->set_cc || !tcpc->get_cc ||
> -           !tcpc->set_polarity || !tcpc->set_vconn || !tcpc->set_vbus ||
> -           !tcpc->set_pd_rx || !tcpc->set_roles || !tcpc->pd_transmit)
> +           !tcpc->get_vbus || !tcpc->set_cc || !tcpc->get_cc || !tcpc->set_polarity ||
> +           !tcpc->set_vconn || !tcpc->set_vbus || !tcpc->set_roles)
>                 return ERR_PTR(-EINVAL);
>
>         port = devm_kzalloc(dev, sizeof(*port), GFP_KERNEL);
> --
> 2.32.0.402.g57bb445576-goog
>