On Mon, Feb 01, 2021 at 04:30:59PM -0800, Badhri Jagan Sridharan wrote:
> The USB Communications Capable bit indicates if port
> partner is capable of communication over the USB data lines
> (e.g. D+/- or SS Tx/Rx). Notify the status of the bit to low
> level drivers to perform chip specific operation.
> For instance, low level driver enables USB switches on D+/D-
> lines to set up data path when the bit is set.
>
> Refactored from patch initially authored by
> Kyle Tso <kyletso@xxxxxxxxxx>
>
> Signed-off-by: Badhri Jagan Sridharan <badhri@xxxxxxxxxx>
Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>
> ---
> Changes since V1:
> - Removed partner_usb_comm_capable flag.
> - Fixed capable flag for SNK_NEGOTIATE_CAPABILITIES.
> ---
> drivers/usb/typec/tcpm/tcpm.c | 13 +++++++++++++
> include/linux/usb/tcpm.h | 5 +++++
> 2 files changed, 18 insertions(+)
>
> diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
> index 0afd8ef692e8..997a1a56c161 100644
> --- a/drivers/usb/typec/tcpm/tcpm.c
> +++ b/drivers/usb/typec/tcpm/tcpm.c
> @@ -3429,6 +3429,14 @@ static void tcpm_unregister_altmodes(struct tcpm_port *port)
> memset(modep, 0, sizeof(*modep));
> }
>
> +static void tcpm_set_partner_usb_comm_capable(struct tcpm_port *port, bool capable)
> +{
> + tcpm_log(port, "Setting usb_comm capable %s", capable ? "true" : "false");
> +
> + if (port->tcpc->set_partner_usb_comm_capable)
> + port->tcpc->set_partner_usb_comm_capable(port->tcpc, capable);
> +}
> +
> static void tcpm_reset_port(struct tcpm_port *port)
> {
> int ret;
> @@ -3445,6 +3453,7 @@ static void tcpm_reset_port(struct tcpm_port *port)
> port->attached = false;
> port->pd_capable = false;
> port->pps_data.supported = false;
> + tcpm_set_partner_usb_comm_capable(port, false);
>
> /*
> * First Rx ID should be 0; set this to a sentinel of -1 so that
> @@ -3785,6 +3794,8 @@ static void run_state_machine(struct tcpm_port *port)
> }
> } else {
> tcpm_pd_send_control(port, PD_CTRL_ACCEPT);
> + tcpm_set_partner_usb_comm_capable(port,
> + !!(port->sink_request & RDO_USB_COMM));
> tcpm_set_state(port, SRC_TRANSITION_SUPPLY,
> PD_T_SRC_TRANSITION);
> }
> @@ -4004,6 +4015,8 @@ static void run_state_machine(struct tcpm_port *port)
> break;
> case SNK_NEGOTIATE_CAPABILITIES:
> port->pd_capable = true;
> + tcpm_set_partner_usb_comm_capable(port,
> + !!(port->source_caps[0] & PDO_FIXED_USB_COMM));
> port->hard_reset_count = 0;
> ret = tcpm_pd_send_request(port);
> if (ret < 0) {
> diff --git a/include/linux/usb/tcpm.h b/include/linux/usb/tcpm.h
> index 3af99f85e8b9..42fcfbe10590 100644
> --- a/include/linux/usb/tcpm.h
> +++ b/include/linux/usb/tcpm.h
> @@ -108,6 +108,10 @@ enum tcpm_transmit_type {
> * is supported by TCPC, set this callback for TCPM to query
> * whether vbus is at VSAFE0V when needed.
> * Returns true when vbus is at VSAFE0V, false otherwise.
> + * @set_partner_usb_comm_capable:
> + * Optional; The USB Communications Capable bit indicates if port
> + * partner is capable of communication over the USB data lines
> + * (e.g. D+/- or SS Tx/Rx). Called to notify the status of the bit.
> */
> struct tcpc_dev {
> struct fwnode_handle *fwnode;
> @@ -139,6 +143,7 @@ struct tcpc_dev {
> int (*set_auto_vbus_discharge_threshold)(struct tcpc_dev *dev, enum typec_pwr_opmode mode,
> bool pps_active, u32 requested_vbus_voltage);
> bool (*is_vbus_vsafe0v)(struct tcpc_dev *dev);
> + void (*set_partner_usb_comm_capable)(struct tcpc_dev *dev, bool enable);
> };
>
> struct tcpm_port;
> --
> 2.30.0.365.g02bc693789-goog
>
