On Tue, Aug 30, 2022 at 10:55 AM Guenter Roeck <linux@xxxxxxxxxxxx> wrote: > > On Fri, Aug 26, 2022 at 01:40:01AM -0700, Badhri Jagan Sridharan wrote: > > Maxim TCPC has additional ADCs and low current(1ua) current source > > to measure the impedance of CC and SBU pins. When tcpm invokes > > the check_contaminant callback, Maxim TCPC measures the impedance > > of the CC & SBU pins and when the impedance measured is less than > > 1MOhm, it is assumed that USB-C port is contaminated. CC comparators > > are also checked to differentiate between presence of sink and > > contaminant. Once USB-C is deemed to be contaminated, MAXIM TCPC > > has additional hardware to disable normal DRP toggling cycle and > > enable 1ua on CC pins once every 2.4secs/4.8secs. Maxim TCPC > > interrupts AP once the impedance on the CC pin is above the > > 1MOhm threshold. The Maxim tcpc driver then signals TCPM_PORT_CLEAN > > to restart toggling. > > > > Signed-off-by: Badhri Jagan Sridharan <badhri@xxxxxxxxxx> > > --- > > drivers/usb/typec/tcpm/Makefile | 2 +- > > drivers/usb/typec/tcpm/maxim_contaminant.c | 338 +++++++++++++++++++++ > > drivers/usb/typec/tcpm/tcpci_maxim.c | 34 ++- > > drivers/usb/typec/tcpm/tcpci_maxim.h | 68 +++++ > > 4 files changed, 429 insertions(+), 13 deletions(-) > > create mode 100644 drivers/usb/typec/tcpm/maxim_contaminant.c > > create mode 100644 drivers/usb/typec/tcpm/tcpci_maxim.h > > > > diff --git a/drivers/usb/typec/tcpm/Makefile b/drivers/usb/typec/tcpm/Makefile > > index 906d9dced8e7..81e4e9421fa0 100644 > > --- a/drivers/usb/typec/tcpm/Makefile > > +++ b/drivers/usb/typec/tcpm/Makefile > > @@ -7,4 +7,4 @@ obj-$(CONFIG_TYPEC_TCPCI) += tcpci.o > > obj-$(CONFIG_TYPEC_RT1711H) += tcpci_rt1711h.o > > obj-$(CONFIG_TYPEC_MT6360) += tcpci_mt6360.o > > obj-$(CONFIG_TYPEC_TCPCI_MT6370) += tcpci_mt6370.o > > -obj-$(CONFIG_TYPEC_TCPCI_MAXIM) += tcpci_maxim.o > > +obj-$(CONFIG_TYPEC_TCPCI_MAXIM) += tcpci_maxim.o maxim_contaminant.o > > This creates two separate modules, which doesn't really add any value. > I would suggest to adjust the file names and create a single module > named tcpci_maxim instead. Renaming tcpci_maxim.c to, say, > tcpci_maxim_core.c and > > obj-$(CONFIG_TYPEC_TCPCI_MAXIM) += tcpci_maxim.o > tcpci_maxim-y := tcpci_maxim_core.o maxim_contaminant.o > > should do. This would also avoid the need for exporting symbols > from tcpci_maxim.c. Thanks Guenter ! Done. Just sent out "[PATCH v2 3/3] usb: typec: maxim_contaminant: Implement check_contaminant callback". > > Thanks, > Guenter
