Hi, > -----Original Message----- > From: Guenter Roeck [mailto:groeck@xxxxxxxxxx] > Sent: Friday, September 30, 2016 12:37 AM > To: Jun Li <jun.li@xxxxxxx> > Cc: Guenter Roeck <groeck@xxxxxxxxxxxx>; Felipe Balbi > <felipe.balbi@xxxxxxxxxxxxxxx>; Chandra Sekhar Anagani > <chandra.sekhar.anagani@xxxxxxxxx>; Bruce Ashfield > <bruce.ashfield@xxxxxxxxxxxxx>; Bin Gao <bin.gao@xxxxxxxxx>; Pranav Tipnis > <pranav.tipnis@xxxxxxxxx>; Heikki Krogerus > <heikki.krogerus@xxxxxxxxxxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx; linux- > usb@xxxxxxxxxxxxxxx > Subject: Re: [RFC PATCH v3 1/2] usb: typec: USB Type-C Port Manager (tcpm) > > On Thu, Sep 29, 2016 at 7:35 AM, Jun Li <jun.li@xxxxxxx> wrote: > > Hi Guenter, > > > >> -----Original Message----- > >> From: linux-usb-owner@xxxxxxxxxxxxxxx [mailto:linux-usb- > >> owner@xxxxxxxxxxxxxxx] On Behalf Of Guenter Roeck > >> Sent: Wednesday, August 24, 2016 5:11 AM > >> To: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx> > >> Cc: Chandra Sekhar Anagani <chandra.sekhar.anagani@xxxxxxxxx>; Bruce > >> Ashfield <bruce.ashfield@xxxxxxxxxxxxx>; Bin Gao <bin.gao@xxxxxxxxx>; > >> Pranav Tipnis <pranav.tipnis@xxxxxxxxx>; Heikki Krogerus > >> <heikki.krogerus@xxxxxxxxxxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx; > >> linux- usb@xxxxxxxxxxxxxxx; Guenter Roeck <groeck@xxxxxxxxxxxx> > >> Subject: [RFC PATCH v3 1/2] usb: typec: USB Type-C Port Manager > >> (tcpm) > >> > >> This driver implements the USB Type-C Power Delivery state machine > >> for both source and sink ports. Alternate mode support is not fully > >> implemented. > >> > >> The driver attaches to the USB Type-C class code implemented in the > >> following patches. > >> > >> usb: typec: add driver for Intel Whiskey Cove PMIC USB Type-C PHY > >> usb: USB Type-C connector class > >> > >> This driver only implements the state machine. Lower level drivers > >> are responsible for > >> - Reporting VBUS status and activating VBUS > >> - Setting CC lines and providing CC line status > >> - Setting line polarity > >> - Activating and deactivating VCONN > >> - Setting the current limit > >> - Activating and deactivating PD message transfers > >> - Sending and receiving PD messages > >> > >> The driver provides both a functional API as well as callbacks for > >> lower level drivers. > >> > >> Signed-off-by: Guenter Roeck <groeck@xxxxxxxxxxxx> > >> --- > >> v3: > >> - Improve TCPM state machine resiliency if there are spurious CC line > >> changes > >> while the state machine is in a transient change (waiting for a > >> timeout) > >> - Update current limit after CC voltage level changes on a port which > >> is not > >> PD capable. > >> > >> v2: > >> - Only update polarity if setting it was successful > >> If setting the CC line polarity in the driver was not successful, > >> don't update the internal polarity state. > >> - All PD messages are little endian; convert to and from CPU endianness. > >> - Avoid comparisons against NULL. > >> - Use u8/u16/u32 instead of uint8_t/uint16_t/uint32_t consistently. > >> - Callbacks into tcpm need to be lockless to avoid timing problems > >> in low level drivers. > >> - Simplify callbacks; tcpm can request the current state of cc/vbus > >> when it is ready to use it. > >> > >> drivers/usb/typec/Kconfig | 7 + > >> drivers/usb/typec/Makefile | 1 + > >> drivers/usb/typec/tcpm.c | 3163 > >> ++++++++++++++++++++++++++++++++++++++++++++ > >> drivers/usb/typec/tcpm.h | 137 ++ > >> include/linux/usb/pd.h | 282 ++++ > >> include/linux/usb/pd_bdo.h | 31 + > >> include/linux/usb/pd_vdo.h | 412 ++++++ > >> 7 files changed, 4033 insertions(+) > >> create mode 100644 drivers/usb/typec/tcpm.c create mode 100644 > >> drivers/usb/typec/tcpm.h create mode 100644 include/linux/usb/pd.h > >> create mode 100644 include/linux/usb/pd_bdo.h create mode 100644 > >> include/linux/usb/pd_vdo.h > >> > > > > ... > > > >> + > >> +static void run_state_machine(struct tcpm_port *port) { > >> + int ret; > >> + > >> + port->enter_state = port->state; > >> + switch (port->state) { > >> + /* SRC states */ > >> + case SRC_UNATTACHED: > >> + tcpm_swap_complete(port, -ENOTCONN); > >> + tcpm_src_detach(port); > >> + tcpm_set_cc(port, TYPEC_CC_RP_DEF); > >> + if (port->typec_caps.type == TYPEC_PORT_DRP) > >> + tcpm_set_state(port, SNK_UNATTACHED, > >> + PD_T_DRP_SNK); > > > > With this and below, after disconnect, the DRP port state machine will > > be in infinite loop of state transition between SRC_UNATTACHED <--> > > SNK_UNATTACHED, correct? > > > > Only while disconnected. It tries to alternatively connect as source and > as sink (being configured as DRP). Once a CC line state change is reported > it will transition out. I have a newer version of the patch (not yet > published) which supports DRP toggling by the TCPC. With that enabled, > TCPM does not change states until a CC state change is reported. > Great, that way will be better, do you plan post your newer patch recently? Thanks Li Jun > Guenter > > > Li Jun > > ... > > > >> + /* SNK states */ > >> + case SNK_UNATTACHED: > >> + tcpm_swap_complete(port, -ENOTCONN); > >> + tcpm_snk_detach(port); > >> + tcpm_set_cc(port, TYPEC_CC_RD); > >> + if (port->typec_caps.type == TYPEC_PORT_DRP) > >> + tcpm_set_state(port, SRC_UNATTACHED, > PD_T_DRP_SRC); > >> + break; > >> ��.n��������+%������w��{.n�����{���)�� jg��� �����ݢj����G���� ���j:+v���w�m������w�������h�����٥
