On Thu, Dec 14, 2023 at 11:08:51PM +0000, RD Babiera wrote:
> Add attempt_vconn_swap_discovery callback to determine whether the TCPM
> should perform a Vconn swap following Discover Identity on SOP. The tcpci
> will return false unless chip level drivers implement the callback.
>
> Maxim based TCPCs will return true unless the last connection resulted in
> a Vconn Over Current Fault, which may be the result of the Vconn swap. In
> addition to the port resetting, the TCPCI will veto the next Vconn swap
> from occurring.
>
> Signed-off-by: RD Babiera <rdbabiera@xxxxxxxxxx>
Reviewed-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
> ---
> drivers/usb/typec/tcpm/tcpci.c | 11 +++++++++++
> drivers/usb/typec/tcpm/tcpci_maxim.h | 1 +
> drivers/usb/typec/tcpm/tcpci_maxim_core.c | 17 ++++++++++++++++-
> include/linux/usb/tcpci.h | 9 +++++++++
> include/linux/usb/tcpm.h | 9 +++++++++
> 5 files changed, 46 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/usb/typec/tcpm/tcpci.c b/drivers/usb/typec/tcpm/tcpci.c
> index 8ea4ed159a13..40c7b6224c74 100644
> --- a/drivers/usb/typec/tcpm/tcpci.c
> +++ b/drivers/usb/typec/tcpm/tcpci.c
> @@ -594,6 +594,16 @@ static bool tcpci_cable_comm_capable(struct tcpc_dev *tcpc)
> return tcpci->data->cable_comm_capable;
> }
>
> +static bool tcpci_attempt_vconn_swap_discovery(struct tcpc_dev *tcpc)
> +{
> + struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
> +
> + if (tcpci->data->attempt_vconn_swap_discovery)
> + return tcpci->data->attempt_vconn_swap_discovery(tcpci, tcpci->data);
> +
> + return false;
> +}
> +
> static int tcpci_init(struct tcpc_dev *tcpc)
> {
> struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
> @@ -804,6 +814,7 @@ struct tcpci *tcpci_register_port(struct device *dev, struct tcpci_data *data)
> 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;
> + tcpci->tcpc.attempt_vconn_swap_discovery = tcpci_attempt_vconn_swap_discovery;
>
> if (tcpci->data->check_contaminant)
> tcpci->tcpc.check_contaminant = tcpci_check_contaminant;
> diff --git a/drivers/usb/typec/tcpm/tcpci_maxim.h b/drivers/usb/typec/tcpm/tcpci_maxim.h
> index 2c1c4d161b0d..78ff3b73ee7e 100644
> --- a/drivers/usb/typec/tcpm/tcpci_maxim.h
> +++ b/drivers/usb/typec/tcpm/tcpci_maxim.h
> @@ -62,6 +62,7 @@ struct max_tcpci_chip {
> struct i2c_client *client;
> struct tcpm_port *port;
> enum contamiant_state contaminant_state;
> + bool veto_vconn_swap;
> };
>
> static inline int max_tcpci_read16(struct max_tcpci_chip *chip, unsigned int reg, u16 *val)
> diff --git a/drivers/usb/typec/tcpm/tcpci_maxim_core.c b/drivers/usb/typec/tcpm/tcpci_maxim_core.c
> index f9f838df43f7..eec3bcec119c 100644
> --- a/drivers/usb/typec/tcpm/tcpci_maxim_core.c
> +++ b/drivers/usb/typec/tcpm/tcpci_maxim_core.c
> @@ -323,8 +323,10 @@ static irqreturn_t _max_tcpci_irq(struct max_tcpci_chip *chip, u16 status)
> if (ret < 0)
> return ret;
>
> - if (reg_status & TCPC_FAULT_STATUS_VCONN_OC)
> + if (reg_status & TCPC_FAULT_STATUS_VCONN_OC) {
> + chip->veto_vconn_swap = true;
> tcpm_port_error_recovery(chip->port);
> + }
> }
>
> if (status & TCPC_ALERT_EXTND) {
> @@ -458,6 +460,18 @@ static void max_tcpci_check_contaminant(struct tcpci *tcpci, struct tcpci_data *
> tcpm_port_clean(chip->port);
> }
>
> +static bool max_tcpci_attempt_vconn_swap_discovery(struct tcpci *tcpci, struct tcpci_data *tdata)
> +{
> + struct max_tcpci_chip *chip = tdata_to_max_tcpci(tdata);
> +
> + if (chip->veto_vconn_swap) {
> + chip->veto_vconn_swap = false;
> + return false;
> + }
> +
> + return true;
> +}
> +
> static int max_tcpci_probe(struct i2c_client *client)
> {
> int ret;
> @@ -493,6 +507,7 @@ static int max_tcpci_probe(struct i2c_client *client)
> 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;
> + chip->data.attempt_vconn_swap_discovery = max_tcpci_attempt_vconn_swap_discovery;
>
> 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 9ed6d62c9c5f..47a86b8a4a50 100644
> --- a/include/linux/usb/tcpci.h
> +++ b/include/linux/usb/tcpci.h
> @@ -201,6 +201,14 @@ struct tcpci;
> * toggling state.
> * @cable_comm_capable
> * optional; Set when TCPC can communicate with cable plugs over SOP'
> + * @attempt_vconn_swap_discovery:
> + * Optional; The callback is called by the TCPM when the result of
> + * a Discover Identity request indicates that the port partner is
> + * a receptacle capable of modal operation. Chip level TCPCI drivers
> + * can implement their own policy to determine if and when a Vconn
> + * swap following Discover Identity on SOP' occurs.
> + * Return true when the TCPM is allowed to request a Vconn swap
> + * after Discovery Identity on SOP.
> */
> struct tcpci_data {
> struct regmap *regmap;
> @@ -219,6 +227,7 @@ struct tcpci_data {
> void (*set_partner_usb_comm_capable)(struct tcpci *tcpci, struct tcpci_data *data,
> bool capable);
> void (*check_contaminant)(struct tcpci *tcpci, struct tcpci_data *data);
> + bool (*attempt_vconn_swap_discovery)(struct tcpci *tcpci, struct tcpci_data *data);
> };
>
> struct tcpci *tcpci_register_port(struct device *dev, struct tcpci_data *data);
> diff --git a/include/linux/usb/tcpm.h b/include/linux/usb/tcpm.h
> index 41d1ac9c8bbf..6671427f7eeb 100644
> --- a/include/linux/usb/tcpm.h
> +++ b/include/linux/usb/tcpm.h
> @@ -122,6 +122,14 @@ enum tcpm_transmit_type {
> * @cable_comm_capable
> * Optional; Returns whether cable communication over SOP' is supported
> * by the tcpc
> + * @attempt_vconn_swap_discovery:
> + * Optional; The callback is called by the TCPM when the result of
> + * a Discover Identity request indicates that the port partner is
> + * a receptacle capable of modal operation. Chip level TCPCI drivers
> + * can implement their own policy to determine if and when a Vconn
> + * swap following Discover Identity on SOP' occurs.
> + * Return true when the TCPM is allowed to request a Vconn swap
> + * after Discovery Identity on SOP.
> */
> struct tcpc_dev {
> struct fwnode_handle *fwnode;
> @@ -158,6 +166,7 @@ struct tcpc_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);
> + bool (*attempt_vconn_swap_discovery)(struct tcpc_dev *dev);
> };
>
> struct tcpm_port;
> --
> 2.43.0.472.g3155946c3a-goog
--
heikki
