| Message ID | 20240108191620.987785-19-rdbabiera@google.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | e03f6fef5ea885f80dc6c7339a7f8aea1b0a609f |
| Headers | show |
| Series | usb: typec: add SOP' support to the tcpm and alt mode drivers | expand |
On Mon, Jan 08, 2024 at 07:16:18PM +0000, RD Babiera wrote: > Add negotiated revision and tx/rx message ids to tcpm_port specific to > SOP'. tx_sop_type is added to the tcpm_port to determine whether the > current constructed message will be sent over SOP or SOP' if not > sent immediately. > > tcpm_pd_rx_handler updates the received message ids. SOP* messages are not > processed afterwards. The handler also calls tcpm_can_communicate_sop_prime > to determine if a SOP' message is directed towards the port, and drops SOP' > messages it should not respond to. > > tcpm_can_communicate_sop_prime is added as a helper to determine whether > the port is capable of communicating over SOP' at a given moment. Being > the Vconn source is a requirement in Power Delivery 3.0 but only a > recommendation in Power Delviery 2.0. Because the port should ensure that > the cable is powered before communication, always enforce the port is the > Vconn source regardless of revision. > > Signed-off-by: RD Babiera <rdbabiera@google.com> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> > --- > Changes since v2: > * Fixed style errors, switch statements with TCPC_TX_SOP now combine > with default case. > --- > drivers/usb/typec/tcpm/tcpm.c | 145 +++++++++++++++++++++++++++++++--- > 1 file changed, 134 insertions(+), 11 deletions(-) > > diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c > index ff0fcf560c88..d2ca85c8fec6 100644 > --- a/drivers/usb/typec/tcpm/tcpm.c > +++ b/drivers/usb/typec/tcpm/tcpm.c > @@ -505,6 +505,35 @@ struct tcpm_port { > * transitions. > */ > bool potential_contaminant; > + > + /* SOP* Related Fields */ > + /* > + * tx_sop_type determines which SOP* a message is being sent on. > + * For messages that are queued and not sent immediately such as in > + * tcpm_queue_message or messages that send after state changes, > + * the tx_sop_type is set accordingly. > + */ > + enum tcpm_transmit_type tx_sop_type; > + /* > + * Prior to discovering the port partner's Specification Revision, the > + * Vconn source and cable plug will use the lower of their two revisions. > + * > + * When the port partner's Specification Revision is discovered, the following > + * rules are put in place. > + * 1. If the cable revision (1) is lower than the revision negotiated > + * between the port and partner (2), the port and partner will communicate > + * on revision (2), but the port and cable will communicate on revision (1). > + * 2. If the cable revision (1) is higher than the revision negotiated > + * between the port and partner (2), the port and partner will communicate > + * on revision (2), and the port and cable will communicate on revision (2) > + * as well. > + */ > + unsigned int negotiated_rev_prime; > + /* > + * Each SOP* type must maintain their own tx and rx message IDs > + */ > + unsigned int message_id_prime; > + unsigned int rx_msgid_prime; > #ifdef CONFIG_DEBUG_FS > struct dentry *dentry; > struct mutex logbuffer_lock; /* log buffer access lock */ > @@ -894,19 +923,30 @@ static void tcpm_ams_finish(struct tcpm_port *port) > } > > static int tcpm_pd_transmit(struct tcpm_port *port, > - enum tcpm_transmit_type type, > + enum tcpm_transmit_type tx_sop_type, > const struct pd_message *msg) > { > unsigned long timeout; > int ret; > + unsigned int negotiated_rev; > + > + switch (tx_sop_type) { > + case TCPC_TX_SOP_PRIME: > + negotiated_rev = port->negotiated_rev_prime; > + break; > + case TCPC_TX_SOP: > + default: > + negotiated_rev = port->negotiated_rev; > + break; > + } > > if (msg) > tcpm_log(port, "PD TX, header: %#x", le16_to_cpu(msg->header)); > else > - tcpm_log(port, "PD TX, type: %#x", type); > + tcpm_log(port, "PD TX, type: %#x", tx_sop_type); > > reinit_completion(&port->tx_complete); > - ret = port->tcpc->pd_transmit(port->tcpc, type, msg, port->negotiated_rev); > + ret = port->tcpc->pd_transmit(port->tcpc, tx_sop_type, msg, negotiated_rev); > if (ret < 0) > return ret; > > @@ -919,7 +959,17 @@ static int tcpm_pd_transmit(struct tcpm_port *port, > > switch (port->tx_status) { > case TCPC_TX_SUCCESS: > - port->message_id = (port->message_id + 1) & PD_HEADER_ID_MASK; > + switch (tx_sop_type) { > + case TCPC_TX_SOP_PRIME: > + port->message_id_prime = (port->message_id_prime + 1) & > + PD_HEADER_ID_MASK; > + break; > + case TCPC_TX_SOP: > + default: > + port->message_id = (port->message_id + 1) & > + PD_HEADER_ID_MASK; > + break; > + } > /* > * USB PD rev 2.0, 8.3.2.2.1: > * USB PD rev 3.0, 8.3.2.1.3: > @@ -1604,6 +1654,57 @@ static void tcpm_register_partner_altmodes(struct tcpm_port *port) > > #define supports_modal(port) PD_IDH_MODAL_SUPP((port)->partner_ident.id_header) > > +/* > + * Helper to determine whether the port is capable of SOP' communication at the > + * current point in time. > + */ > +static bool tcpm_can_communicate_sop_prime(struct tcpm_port *port) > +{ > + /* Check to see if tcpc supports SOP' communication */ > + if (!port->tcpc->cable_comm_capable || !port->tcpc->cable_comm_capable(port->tcpc)) > + return false; > + /* > + * Power Delivery 2.0 Section 6.3.11 > + * Before communicating with a Cable Plug a Port Should ensure that it > + * is the Vconn Source and that the Cable Plugs are powered by > + * performing a Vconn swap if necessary. Since it cannot be guaranteed > + * that the present Vconn Source is supplying Vconn, the only means to > + * ensure that the Cable Plugs are powered is for a Port wishing to > + * communicate with a Cable Plug is to become the Vconn Source. > + * > + * Power Delivery 3.0 Section 6.3.11 > + * Before communicating with a Cable Plug a Port Shall ensure that it > + * is the Vconn source. > + */ > + if (port->vconn_role != TYPEC_SOURCE) > + return false; > + /* > + * Power Delivery 2.0 Section 2.4.4 > + * When no Contract or an Implicit Contract is in place the Source can > + * communicate with a Cable Plug using SOP' packets in order to discover > + * its characteristics. > + * > + * Power Delivery 3.0 Section 2.4.4 > + * When no Contract or an Implicit Contract is in place only the Source > + * port that is supplying Vconn is allowed to send packets to a Cable > + * Plug and is allowed to respond to packets from the Cable Plug. > + */ > + if (!port->explicit_contract) > + return port->pwr_role == TYPEC_SOURCE; > + if (port->negotiated_rev == PD_REV30) > + return true; > + /* > + * Power Delivery 2.0 Section 2.4.4 > + * > + * When an Explicit Contract is in place the DFP (either the Source or > + * the Sink) can communicate with the Cable Plug(s) using SOP’/SOP” > + * Packets (see Figure 2-3). > + */ > + if (port->negotiated_rev == PD_REV20) > + return port->data_role == TYPEC_HOST; > + return false; > +} > + > static int tcpm_pd_svdm(struct tcpm_port *port, struct typec_altmode *adev, > const u32 *p, int cnt, u32 *response, > enum adev_actions *adev_action) > @@ -2989,14 +3090,18 @@ static void tcpm_pd_rx_handler(struct kthread_work *work) > tcpm_log(port, "PD RX, header: %#x [%d]", le16_to_cpu(msg->header), > port->attached); > > - /* Ignore SOP' for now */ > - if (rx_sop_type == TCPC_TX_SOP_PRIME) > - goto done; > - > if (port->attached) { > enum pd_ctrl_msg_type type = pd_header_type_le(msg->header); > unsigned int msgid = pd_header_msgid_le(msg->header); > > + /* > + * Drop SOP' messages if cannot receive via > + * tcpm_can_communicate_sop_prime > + */ > + if (rx_sop_type == TCPC_TX_SOP_PRIME && > + !tcpm_can_communicate_sop_prime(port)) > + goto done; > + > /* > * USB PD standard, 6.6.1.2: > * "... if MessageID value in a received Message is the > @@ -3006,16 +3111,27 @@ static void tcpm_pd_rx_handler(struct kthread_work *work) > * Message). Note: this shall not apply to the Soft_Reset > * Message which always has a MessageID value of zero." > */ > - if (msgid == port->rx_msgid && type != PD_CTRL_SOFT_RESET) > + switch (rx_sop_type) { > + case TCPC_TX_SOP_PRIME: > + if (msgid == port->rx_msgid_prime) > + goto done; > + port->rx_msgid_prime = msgid; > + /* Ignore SOP' for now */ > goto done; > - port->rx_msgid = msgid; > + case TCPC_TX_SOP: > + default: > + if (msgid == port->rx_msgid && type != PD_CTRL_SOFT_RESET) > + goto done; > + port->rx_msgid = msgid; > + break; > + } > > /* > * If both ends believe to be DFP/host, we have a data role > * mismatch. > */ > if (!!(le16_to_cpu(msg->header) & PD_HEADER_DATA_ROLE) == > - (port->data_role == TYPEC_HOST)) { > + (port->data_role == TYPEC_HOST) && rx_sop_type == TCPC_TX_SOP) { > tcpm_log(port, > "Data role mismatch, initiating error recovery"); > tcpm_set_state(port, ERROR_RECOVERY, 0); > @@ -3720,6 +3836,7 @@ static void tcpm_reset_port(struct tcpm_port *port) > * we can check tcpm_pd_rx_handler() if we had seen it before. > */ > port->rx_msgid = -1; > + port->rx_msgid_prime = -1; > > port->tcpc->set_pd_rx(port->tcpc, false); > tcpm_init_vbus(port); /* also disables charging */ > @@ -4034,8 +4151,11 @@ static void run_state_machine(struct tcpm_port *port) > port->pwr_opmode = TYPEC_PWR_MODE_USB; > port->caps_count = 0; > port->negotiated_rev = PD_MAX_REV; > + port->negotiated_rev_prime = PD_MAX_REV; > port->message_id = 0; > + port->message_id_prime = 0; > port->rx_msgid = -1; > + port->rx_msgid_prime = -1; > port->explicit_contract = false; > /* SNK -> SRC POWER/FAST_ROLE_SWAP finished */ > if (port->ams == POWER_ROLE_SWAP || > @@ -4275,8 +4395,11 @@ static void run_state_machine(struct tcpm_port *port) > typec_set_pwr_opmode(port->typec_port, opmode); > port->pwr_opmode = TYPEC_PWR_MODE_USB; > port->negotiated_rev = PD_MAX_REV; > + port->negotiated_rev_prime = PD_MAX_REV; > port->message_id = 0; > + port->message_id_prime = 0; > port->rx_msgid = -1; > + port->rx_msgid_prime = -1; > port->explicit_contract = false; > > if (port->ams == POWER_ROLE_SWAP || > -- > 2.43.0.472.g3155946c3a-goog
diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c index ff0fcf560c88..d2ca85c8fec6 100644 --- a/drivers/usb/typec/tcpm/tcpm.c +++ b/drivers/usb/typec/tcpm/tcpm.c @@ -505,6 +505,35 @@ struct tcpm_port { * transitions. */ bool potential_contaminant; + + /* SOP* Related Fields */ + /* + * tx_sop_type determines which SOP* a message is being sent on. + * For messages that are queued and not sent immediately such as in + * tcpm_queue_message or messages that send after state changes, + * the tx_sop_type is set accordingly. + */ + enum tcpm_transmit_type tx_sop_type; + /* + * Prior to discovering the port partner's Specification Revision, the + * Vconn source and cable plug will use the lower of their two revisions. + * + * When the port partner's Specification Revision is discovered, the following + * rules are put in place. + * 1. If the cable revision (1) is lower than the revision negotiated + * between the port and partner (2), the port and partner will communicate + * on revision (2), but the port and cable will communicate on revision (1). + * 2. If the cable revision (1) is higher than the revision negotiated + * between the port and partner (2), the port and partner will communicate + * on revision (2), and the port and cable will communicate on revision (2) + * as well. + */ + unsigned int negotiated_rev_prime; + /* + * Each SOP* type must maintain their own tx and rx message IDs + */ + unsigned int message_id_prime; + unsigned int rx_msgid_prime; #ifdef CONFIG_DEBUG_FS struct dentry *dentry; struct mutex logbuffer_lock; /* log buffer access lock */ @@ -894,19 +923,30 @@ static void tcpm_ams_finish(struct tcpm_port *port) } static int tcpm_pd_transmit(struct tcpm_port *port, - enum tcpm_transmit_type type, + enum tcpm_transmit_type tx_sop_type, const struct pd_message *msg) { unsigned long timeout; int ret; + unsigned int negotiated_rev; + + switch (tx_sop_type) { + case TCPC_TX_SOP_PRIME: + negotiated_rev = port->negotiated_rev_prime; + break; + case TCPC_TX_SOP: + default: + negotiated_rev = port->negotiated_rev; + break; + } if (msg) tcpm_log(port, "PD TX, header: %#x", le16_to_cpu(msg->header)); else - tcpm_log(port, "PD TX, type: %#x", type); + tcpm_log(port, "PD TX, type: %#x", tx_sop_type); reinit_completion(&port->tx_complete); - ret = port->tcpc->pd_transmit(port->tcpc, type, msg, port->negotiated_rev); + ret = port->tcpc->pd_transmit(port->tcpc, tx_sop_type, msg, negotiated_rev); if (ret < 0) return ret; @@ -919,7 +959,17 @@ static int tcpm_pd_transmit(struct tcpm_port *port, switch (port->tx_status) { case TCPC_TX_SUCCESS: - port->message_id = (port->message_id + 1) & PD_HEADER_ID_MASK; + switch (tx_sop_type) { + case TCPC_TX_SOP_PRIME: + port->message_id_prime = (port->message_id_prime + 1) & + PD_HEADER_ID_MASK; + break; + case TCPC_TX_SOP: + default: + port->message_id = (port->message_id + 1) & + PD_HEADER_ID_MASK; + break; + } /* * USB PD rev 2.0, 8.3.2.2.1: * USB PD rev 3.0, 8.3.2.1.3: @@ -1604,6 +1654,57 @@ static void tcpm_register_partner_altmodes(struct tcpm_port *port) #define supports_modal(port) PD_IDH_MODAL_SUPP((port)->partner_ident.id_header) +/* + * Helper to determine whether the port is capable of SOP' communication at the + * current point in time. + */ +static bool tcpm_can_communicate_sop_prime(struct tcpm_port *port) +{ + /* Check to see if tcpc supports SOP' communication */ + if (!port->tcpc->cable_comm_capable || !port->tcpc->cable_comm_capable(port->tcpc)) + return false; + /* + * Power Delivery 2.0 Section 6.3.11 + * Before communicating with a Cable Plug a Port Should ensure that it + * is the Vconn Source and that the Cable Plugs are powered by + * performing a Vconn swap if necessary. Since it cannot be guaranteed + * that the present Vconn Source is supplying Vconn, the only means to + * ensure that the Cable Plugs are powered is for a Port wishing to + * communicate with a Cable Plug is to become the Vconn Source. + * + * Power Delivery 3.0 Section 6.3.11 + * Before communicating with a Cable Plug a Port Shall ensure that it + * is the Vconn source. + */ + if (port->vconn_role != TYPEC_SOURCE) + return false; + /* + * Power Delivery 2.0 Section 2.4.4 + * When no Contract or an Implicit Contract is in place the Source can + * communicate with a Cable Plug using SOP' packets in order to discover + * its characteristics. + * + * Power Delivery 3.0 Section 2.4.4 + * When no Contract or an Implicit Contract is in place only the Source + * port that is supplying Vconn is allowed to send packets to a Cable + * Plug and is allowed to respond to packets from the Cable Plug. + */ + if (!port->explicit_contract) + return port->pwr_role == TYPEC_SOURCE; + if (port->negotiated_rev == PD_REV30) + return true; + /* + * Power Delivery 2.0 Section 2.4.4 + * + * When an Explicit Contract is in place the DFP (either the Source or + * the Sink) can communicate with the Cable Plug(s) using SOP’/SOP” + * Packets (see Figure 2-3). + */ + if (port->negotiated_rev == PD_REV20) + return port->data_role == TYPEC_HOST; + return false; +} + static int tcpm_pd_svdm(struct tcpm_port *port, struct typec_altmode *adev, const u32 *p, int cnt, u32 *response, enum adev_actions *adev_action) @@ -2989,14 +3090,18 @@ static void tcpm_pd_rx_handler(struct kthread_work *work) tcpm_log(port, "PD RX, header: %#x [%d]", le16_to_cpu(msg->header), port->attached); - /* Ignore SOP' for now */ - if (rx_sop_type == TCPC_TX_SOP_PRIME) - goto done; - if (port->attached) { enum pd_ctrl_msg_type type = pd_header_type_le(msg->header); unsigned int msgid = pd_header_msgid_le(msg->header); + /* + * Drop SOP' messages if cannot receive via + * tcpm_can_communicate_sop_prime + */ + if (rx_sop_type == TCPC_TX_SOP_PRIME && + !tcpm_can_communicate_sop_prime(port)) + goto done; + /* * USB PD standard, 6.6.1.2: * "... if MessageID value in a received Message is the @@ -3006,16 +3111,27 @@ static void tcpm_pd_rx_handler(struct kthread_work *work) * Message). Note: this shall not apply to the Soft_Reset * Message which always has a MessageID value of zero." */ - if (msgid == port->rx_msgid && type != PD_CTRL_SOFT_RESET) + switch (rx_sop_type) { + case TCPC_TX_SOP_PRIME: + if (msgid == port->rx_msgid_prime) + goto done; + port->rx_msgid_prime = msgid; + /* Ignore SOP' for now */ goto done; - port->rx_msgid = msgid; + case TCPC_TX_SOP: + default: + if (msgid == port->rx_msgid && type != PD_CTRL_SOFT_RESET) + goto done; + port->rx_msgid = msgid; + break; + } /* * If both ends believe to be DFP/host, we have a data role * mismatch. */ if (!!(le16_to_cpu(msg->header) & PD_HEADER_DATA_ROLE) == - (port->data_role == TYPEC_HOST)) { + (port->data_role == TYPEC_HOST) && rx_sop_type == TCPC_TX_SOP) { tcpm_log(port, "Data role mismatch, initiating error recovery"); tcpm_set_state(port, ERROR_RECOVERY, 0); @@ -3720,6 +3836,7 @@ static void tcpm_reset_port(struct tcpm_port *port) * we can check tcpm_pd_rx_handler() if we had seen it before. */ port->rx_msgid = -1; + port->rx_msgid_prime = -1; port->tcpc->set_pd_rx(port->tcpc, false); tcpm_init_vbus(port); /* also disables charging */ @@ -4034,8 +4151,11 @@ static void run_state_machine(struct tcpm_port *port) port->pwr_opmode = TYPEC_PWR_MODE_USB; port->caps_count = 0; port->negotiated_rev = PD_MAX_REV; + port->negotiated_rev_prime = PD_MAX_REV; port->message_id = 0; + port->message_id_prime = 0; port->rx_msgid = -1; + port->rx_msgid_prime = -1; port->explicit_contract = false; /* SNK -> SRC POWER/FAST_ROLE_SWAP finished */ if (port->ams == POWER_ROLE_SWAP || @@ -4275,8 +4395,11 @@ static void run_state_machine(struct tcpm_port *port) typec_set_pwr_opmode(port->typec_port, opmode); port->pwr_opmode = TYPEC_PWR_MODE_USB; port->negotiated_rev = PD_MAX_REV; + port->negotiated_rev_prime = PD_MAX_REV; port->message_id = 0; + port->message_id_prime = 0; port->rx_msgid = -1; + port->rx_msgid_prime = -1; port->explicit_contract = false; if (port->ams == POWER_ROLE_SWAP ||
Add negotiated revision and tx/rx message ids to tcpm_port specific to SOP'. tx_sop_type is added to the tcpm_port to determine whether the current constructed message will be sent over SOP or SOP' if not sent immediately. tcpm_pd_rx_handler updates the received message ids. SOP* messages are not processed afterwards. The handler also calls tcpm_can_communicate_sop_prime to determine if a SOP' message is directed towards the port, and drops SOP' messages it should not respond to. tcpm_can_communicate_sop_prime is added as a helper to determine whether the port is capable of communicating over SOP' at a given moment. Being the Vconn source is a requirement in Power Delivery 3.0 but only a recommendation in Power Delviery 2.0. Because the port should ensure that the cable is powered before communication, always enforce the port is the Vconn source regardless of revision. Signed-off-by: RD Babiera <rdbabiera@google.com> --- Changes since v2: * Fixed style errors, switch statements with TCPC_TX_SOP now combine with default case. --- drivers/usb/typec/tcpm/tcpm.c | 145 +++++++++++++++++++++++++++++++--- 1 file changed, 134 insertions(+), 11 deletions(-)