From: Xu Yang xu.yang_2@nxp.com
commit 5638b0dfb6921f69943c705383ff40fb64b987f2 upstream.
With the AMS and Collision Avoidance, tcpm often needs to change the CC's termination. When one CC line is sourcing Vconn, if we still change its termination, the voltage of the another CC line is likely to be fluctuant and unstable.
Therefore, we should verify whether a CC line is sourcing Vconn before changing its termination and only change the termination that is not a Vconn line. This can be done by reading the Vconn Present bit of POWER_ STATUS register. To determine the polarity, we can read the Plug Orientation bit of TCPC_CONTROL register. Since Vconn can only be sourced if Plug Orientation is set.
Fixes: 0908c5aca31e ("usb: typec: tcpm: AMS and Collision Avoidance") cc: stable@vger.kernel.org Reviewed-by: Guenter Roeck linux@roeck-us.net Acked-by: Heikki Krogerus heikki.krogerus@linux.intel.com Signed-off-by: Xu Yang xu.yang_2@nxp.com Link: https://lore.kernel.org/r/20220113092943.752372-1-xu.yang_2@nxp.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/usb/typec/tcpm/tcpci.c | 26 ++++++++++++++++++++++++++ drivers/usb/typec/tcpm/tcpci.h | 1 + 2 files changed, 27 insertions(+)
--- a/drivers/usb/typec/tcpm/tcpci.c +++ b/drivers/usb/typec/tcpm/tcpci.c @@ -75,9 +75,25 @@ static int tcpci_write16(struct tcpci *t static int tcpci_set_cc(struct tcpc_dev *tcpc, enum typec_cc_status cc) { struct tcpci *tcpci = tcpc_to_tcpci(tcpc); + bool vconn_pres; + enum typec_cc_polarity polarity = TYPEC_POLARITY_CC1; unsigned int reg; int ret;
+ ret = regmap_read(tcpci->regmap, TCPC_POWER_STATUS, ®); + if (ret < 0) + return ret; + + vconn_pres = !!(reg & TCPC_POWER_STATUS_VCONN_PRES); + if (vconn_pres) { + ret = regmap_read(tcpci->regmap, TCPC_TCPC_CTRL, ®); + if (ret < 0) + return ret; + + if (reg & TCPC_TCPC_CTRL_ORIENTATION) + polarity = TYPEC_POLARITY_CC2; + } + switch (cc) { case TYPEC_CC_RA: reg = (TCPC_ROLE_CTRL_CC_RA << TCPC_ROLE_CTRL_CC1_SHIFT) | @@ -112,6 +128,16 @@ static int tcpci_set_cc(struct tcpc_dev break; }
+ if (vconn_pres) { + if (polarity == TYPEC_POLARITY_CC2) { + reg &= ~(TCPC_ROLE_CTRL_CC1_MASK << TCPC_ROLE_CTRL_CC1_SHIFT); + reg |= (TCPC_ROLE_CTRL_CC_OPEN << TCPC_ROLE_CTRL_CC1_SHIFT); + } else { + reg &= ~(TCPC_ROLE_CTRL_CC2_MASK << TCPC_ROLE_CTRL_CC2_SHIFT); + reg |= (TCPC_ROLE_CTRL_CC_OPEN << TCPC_ROLE_CTRL_CC2_SHIFT); + } + } + ret = regmap_write(tcpci->regmap, TCPC_ROLE_CTRL, reg); if (ret < 0) return ret; --- a/drivers/usb/typec/tcpm/tcpci.h +++ b/drivers/usb/typec/tcpm/tcpci.h @@ -98,6 +98,7 @@ #define TCPC_POWER_STATUS_SOURCING_VBUS BIT(4) #define TCPC_POWER_STATUS_VBUS_DET BIT(3) #define TCPC_POWER_STATUS_VBUS_PRES BIT(2) +#define TCPC_POWER_STATUS_VCONN_PRES BIT(1) #define TCPC_POWER_STATUS_SINKING_VBUS BIT(0)
#define TCPC_FAULT_STATUS 0x1f