diff options
| author | Badhri Jagan Sridharan <badhri@google.com> | 2020-10-28 23:31:35 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-11-18 12:57:49 +0100 |
| commit | f321a02caebdd0c56e167610cda2fa148cd96e8b (patch) | |
| tree | 767b926ec993ea0ae3f449e43a2ef4593d594697 /include/linux | |
| parent | 2fc58b36e919902ae2f17531783d8debadcc2a27 (diff) | |
usb: typec: tcpm: Implement enabling Auto Discharge disconnect support
TCPCI spec allows TCPC hardware to autonomously discharge the vbus
capacitance upon disconnect. The expectation is that the TCPM enables
AutoDischargeDisconnect while entering SNK/SRC_ATTACHED states. Hardware
then automously discharges vbus when the vbus falls below a certain
threshold i.e. VBUS_SINK_DISCONNECT_THRESHOLD.
Apart from enabling the vbus discharge circuit, AutoDischargeDisconnect
is also used a flag to move TCPCI based TCPC implementations into
Attached.Snk/Attached.Src state as mentioned in
Figure 4-15. TCPC State Diagram before a Connection of the
USB Type-C Port Controller Interface Specification.
In such TCPC implementations, setting AutoDischargeDisconnect would
prevent TCPC into entering "Connection_Invalid" state as well.
Signed-off-by: Badhri Jagan Sridharan <badhri@google.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20201029063138.1429760-8-badhri@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/usb/tcpm.h | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/include/linux/usb/tcpm.h b/include/linux/usb/tcpm.h index 7303f518ba49..e68aaa12886f 100644 --- a/include/linux/usb/tcpm.h +++ b/include/linux/usb/tcpm.h @@ -86,6 +86,18 @@ enum tcpm_transmit_type { * @frs_sourcing_vbus: * Optional; Called to notify that vbus is now being sourced. * Low level drivers can perform chip specific operations, if any. + * @enable_auto_vbus_discharge: + * Optional; TCPCI spec based TCPC implementations can optionally + * support hardware to autonomously dischrge vbus upon disconnecting + * as sink or source. TCPM signals TCPC to enable the mechanism upon + * entering connected state and signals disabling upon disconnect. + * @set_auto_vbus_discharge_threshold: + * Mandatory when enable_auto_vbus_discharge is implemented. TCPM + * calls this function to allow lower levels drivers to program the + * vbus threshold voltage below which the vbus discharge circuit + * will be turned on. requested_vbus_voltage is set to 0 when vbus + * is going to disappear knowingly i.e. during PR_SWAP and + * HARD_RESET etc. */ struct tcpc_dev { struct fwnode_handle *fwnode; @@ -113,6 +125,9 @@ struct tcpc_dev { int (*set_bist_data)(struct tcpc_dev *dev, bool on); int (*enable_frs)(struct tcpc_dev *dev, bool enable); void (*frs_sourcing_vbus)(struct tcpc_dev *dev); + int (*enable_auto_vbus_discharge)(struct tcpc_dev *dev, bool enable); + int (*set_auto_vbus_discharge_threshold)(struct tcpc_dev *dev, enum typec_pwr_opmode mode, + bool pps_active, u32 requested_vbus_voltage); }; struct tcpm_port; |