Re: [PATCH v2 03/12] usb: typec: tcpci: add cable_comm_capable attribute

[Heikki Krogerus <heikki.krogerus@linux.intel.com>]

On Thu, Dec 14, 2023 at 11:08:47PM +0000, RD Babiera wrote:
> Add cable_comm_capable to tcpci_data for tcpci drivers to indicate that
> the port tcpc is capable of communicating to cables over SOP. A
> corresponding tcpci callback tcpci_cable_comm_capable returns this value.
> The tcpm will primarily use this in later patches to determine if the port
> can transmit and receive SOP' messages.
> 
> Maxim based tcpci drivers are capable of SOP' communication, so the
> cable_comm_capable flag is set to true.
> 
> Signed-off-by: RD Babiera <rdbabiera@google.com>

Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>

> ---
> Changes since v1:
> * Moved tcpm_pd_receive changes to separate patch
> ---
>  drivers/usb/typec/tcpm/tcpci.c            | 8 ++++++++
>  drivers/usb/typec/tcpm/tcpci_maxim_core.c | 1 +
>  include/linux/usb/tcpci.h                 | 3 +++
>  include/linux/usb/tcpm.h                  | 4 ++++
>  4 files changed, 16 insertions(+)
> 
> diff --git a/drivers/usb/typec/tcpm/tcpci.c b/drivers/usb/typec/tcpm/tcpci.c
> index 0ee3e6e29bb1..1ededbcecc09 100644
> --- a/drivers/usb/typec/tcpm/tcpci.c
> +++ b/drivers/usb/typec/tcpm/tcpci.c
> @@ -584,6 +584,13 @@ static int tcpci_pd_transmit(struct tcpc_dev *tcpc, enum tcpm_transmit_type type
>  	return 0;
>  }
>  
> +static bool tcpci_cable_comm_capable(struct tcpc_dev *tcpc)
> +{
> +	struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
> +
> +	return tcpci->data->cable_comm_capable;
> +}
> +
>  static int tcpci_init(struct tcpc_dev *tcpc)
>  {
>  	struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
> @@ -793,6 +800,7 @@ struct tcpci *tcpci_register_port(struct device *dev, struct tcpci_data *data)
>  	tcpci->tcpc.enable_frs = tcpci_enable_frs;
>  	tcpci->tcpc.frs_sourcing_vbus = tcpci_frs_sourcing_vbus;
>  	tcpci->tcpc.set_partner_usb_comm_capable = tcpci_set_partner_usb_comm_capable;
> +	tcpci->tcpc.cable_comm_capable = tcpci_cable_comm_capable;
>  
>  	if (tcpci->data->check_contaminant)
>  		tcpci->tcpc.check_contaminant = tcpci_check_contaminant;
> diff --git a/drivers/usb/typec/tcpm/tcpci_maxim_core.c b/drivers/usb/typec/tcpm/tcpci_maxim_core.c
> index 7fb966fd639b..7b2d4e6e52a2 100644
> --- a/drivers/usb/typec/tcpm/tcpci_maxim_core.c
> +++ b/drivers/usb/typec/tcpm/tcpci_maxim_core.c
> @@ -478,6 +478,7 @@ static int max_tcpci_probe(struct i2c_client *client)
>  	chip->data.vbus_vsafe0v = true;
>  	chip->data.set_partner_usb_comm_capable = max_tcpci_set_partner_usb_comm_capable;
>  	chip->data.check_contaminant = max_tcpci_check_contaminant;
> +	chip->data.cable_comm_capable = true;
>  
>  	max_tcpci_init_regs(chip);
>  	chip->tcpci = tcpci_register_port(chip->dev, &chip->data);
> diff --git a/include/linux/usb/tcpci.h b/include/linux/usb/tcpci.h
> index 467e8045e9f8..1d0b849defd0 100644
> --- a/include/linux/usb/tcpci.h
> +++ b/include/linux/usb/tcpci.h
> @@ -198,12 +198,15 @@ struct tcpci;
>   *		Chip level drivers are expected to check for contaminant and call
>   *		tcpm_clean_port when the port is clean to put the port back into
>   *		toggling state.
> + * @cable_comm_capable
> + *		optional; Set when TCPC can communicate with cable plugs over SOP'
>   */
>  struct tcpci_data {
>  	struct regmap *regmap;
>  	unsigned char TX_BUF_BYTE_x_hidden:1;
>  	unsigned char auto_discharge_disconnect:1;
>  	unsigned char vbus_vsafe0v:1;
> +	unsigned char cable_comm_capable:1;
>  
>  	int (*init)(struct tcpci *tcpci, struct tcpci_data *data);
>  	int (*set_vconn)(struct tcpci *tcpci, struct tcpci_data *data,
> diff --git a/include/linux/usb/tcpm.h b/include/linux/usb/tcpm.h
> index 65fac5e1f317..430fa3ec69bb 100644
> --- a/include/linux/usb/tcpm.h
> +++ b/include/linux/usb/tcpm.h
> @@ -119,6 +119,9 @@ enum tcpm_transmit_type {
>   *		at the end of the deboumce period or when the port is still
>   *		toggling. Chip level drivers are expected to check for contaminant
>   *		and call tcpm_clean_port when the port is clean.
> + * @cable_comm_capable
> + *		Optional; Returns whether cable communication over SOP' is supported
> + *		by the tcpc
>   */
>  struct tcpc_dev {
>  	struct fwnode_handle *fwnode;
> @@ -154,6 +157,7 @@ struct tcpc_dev {
>  	bool (*is_vbus_vsafe0v)(struct tcpc_dev *dev);
>  	void (*set_partner_usb_comm_capable)(struct tcpc_dev *dev, bool enable);
>  	void (*check_contaminant)(struct tcpc_dev *dev);
> +	bool (*cable_comm_capable)(struct tcpc_dev *dev);
>  };
>  
>  struct tcpm_port;
> -- 
> 2.43.0.472.g3155946c3a-goog

-- 
heikki