On Thu, Mar 19, 2015 at 11:11:20AM +0800, Li Jun wrote: > Adds HNP polling timer when transits to host state, the OTG status request > will be sent to peripheral after timeout, if host request flag is set, it will > switch to peripheral state, otherwise it will repeat HNP polling every 1.5s and > maintain the current session. Signed-off-by: Peter Chen <peter.chen@xxxxxxxxxxxxx> > > Signed-off-by: Li Jun <jun.li@xxxxxxxxxxxxx> > --- > drivers/usb/common/usb-otg-fsm.c | 92 ++++++++++++++++++++++++++++++++++++++ > include/linux/usb/otg-fsm.h | 13 ++++++ > 2 files changed, 105 insertions(+) > > diff --git a/drivers/usb/common/usb-otg-fsm.c b/drivers/usb/common/usb-otg-fsm.c > index 61d538a..6f0d40b 100644 > --- a/drivers/usb/common/usb-otg-fsm.c > +++ b/drivers/usb/common/usb-otg-fsm.c > @@ -78,6 +78,8 @@ static void otg_leave_state(struct otg_fsm *fsm, enum usb_otg_state old_state) > fsm->b_srp_done = 0; > break; > case OTG_STATE_B_PERIPHERAL: > + if (fsm->otg->gadget) > + fsm->otg->gadget->host_request_flag = 0; > break; > case OTG_STATE_B_WAIT_ACON: > otg_del_timer(fsm, B_ASE0_BRST); > @@ -107,6 +109,8 @@ static void otg_leave_state(struct otg_fsm *fsm, enum usb_otg_state old_state) > case OTG_STATE_A_PERIPHERAL: > otg_del_timer(fsm, A_BIDL_ADIS); > fsm->a_bidl_adis_tmout = 0; > + if (fsm->otg->gadget) > + fsm->otg->gadget->host_request_flag = 0; > break; > case OTG_STATE_A_WAIT_VFALL: > otg_del_timer(fsm, A_WAIT_VFALL); > @@ -120,6 +124,92 @@ static void otg_leave_state(struct otg_fsm *fsm, enum usb_otg_state old_state) > } > } > > +static void otg_hnp_polling_work(struct work_struct *work) > +{ > + struct otg_fsm *fsm = container_of(to_delayed_work(work), > + struct otg_fsm, hnp_polling_work); > + struct usb_device *udev; > + u8 host_req_flag; > + enum usb_otg_state state = fsm->otg->state; > + struct usb_otg_descriptor *desc = NULL; > + int retval; > + > + if (state != OTG_STATE_A_HOST && state != OTG_STATE_B_HOST) > + return; > + > + udev = usb_hub_find_child(fsm->otg->host->root_hub, 1); > + if (!udev) { > + dev_err(fsm->otg->host->controller, > + "no usb dev connected, can't start HNP polling\n"); > + return; > + } > + > + /* Check if it's a HNP capable OTG device */ > + retval = __usb_get_extra_descriptor(udev->rawdescriptors[0], > + le16_to_cpu(udev->config[0].desc.wTotalLength), > + USB_DT_OTG, (void **) &desc); > + if (retval || !(desc->bmAttributes & USB_OTG_HNP)) > + return; > + > + /* Get host request flag from connected USB device */ > + retval = usb_control_msg(udev, > + usb_rcvctrlpipe(udev, 0), > + USB_REQ_GET_STATUS, > + USB_DIR_IN | USB_RECIP_DEVICE, > + 0, > + OTG_STS_SELECTOR, > + &host_req_flag, > + 1, > + USB_CTRL_GET_TIMEOUT); > + if (retval != 1) { > + dev_err(&udev->dev, "Get one byte OTG status failed\n"); > + return; > + } > + > + if (host_req_flag == 0) { > + /* Continue HNP polling */ > + schedule_delayed_work(&fsm->hnp_polling_work, > + msecs_to_jiffies(T_HOST_REQ_POLL)); > + return; > + } else if (host_req_flag != HOST_REQUEST_FLAG) { > + dev_err(&udev->dev, "host request flag %d is invalid\n", > + host_req_flag); > + return; > + } > + > + /* Host request flag is set */ > + if (state == OTG_STATE_A_HOST) { > + /* Set b_hnp_enable */ > + if (!fsm->otg->host->b_hnp_enable) { > + retval = usb_control_msg(udev, > + usb_sndctrlpipe(udev, 0), > + USB_REQ_SET_FEATURE, 0, > + USB_DEVICE_B_HNP_ENABLE, > + 0, NULL, 0, > + USB_CTRL_SET_TIMEOUT); > + if (retval < 0) { > + dev_err(&udev->dev, > + "can't enable HNP %d\n", retval); > + return; > + } > + fsm->otg->host->b_hnp_enable = 1; > + } > + > + fsm->a_bus_req = 0; > + } else if (state == OTG_STATE_B_HOST) { > + fsm->b_bus_req = 0; > + } > + > + otg_statemachine(fsm); > +} > + > +static void otg_start_hnp_polling(struct otg_fsm *fsm) > +{ > + INIT_DELAYED_WORK(&fsm->hnp_polling_work, otg_hnp_polling_work); > + schedule_delayed_work(&fsm->hnp_polling_work, > + msecs_to_jiffies(T_HOST_REQ_POLL)); > +} > + > /* Called when entering a state */ > static int otg_set_state(struct otg_fsm *fsm, enum usb_otg_state new_state) > { > @@ -169,6 +259,7 @@ static int otg_set_state(struct otg_fsm *fsm, enum usb_otg_state new_state) > otg_set_protocol(fsm, PROTO_HOST); > usb_bus_start_enum(fsm->otg->host, > fsm->otg->host->otg_port); > + otg_start_hnp_polling(fsm); > break; > case OTG_STATE_A_IDLE: > otg_drv_vbus(fsm, 0); > @@ -203,6 +294,7 @@ static int otg_set_state(struct otg_fsm *fsm, enum usb_otg_state new_state) > */ > if (!fsm->a_bus_req || fsm->a_suspend_req_inf) > otg_add_timer(fsm, A_WAIT_ENUM); > + otg_start_hnp_polling(fsm); > break; > case OTG_STATE_A_SUSPEND: > otg_drv_vbus(fsm, 1); > diff --git a/include/linux/usb/otg-fsm.h b/include/linux/usb/otg-fsm.h > index f728f18..2bea252 100644 > --- a/include/linux/usb/otg-fsm.h > +++ b/include/linux/usb/otg-fsm.h > @@ -40,6 +40,18 @@ > #define PROTO_HOST (1) > #define PROTO_GADGET (2) > > +#define OTG_STS_SELECTOR 0xF000 /* OTG status selector, according to > + * OTG and EH 2.0 Chapter 6.2.3 > + * Table:6-4 > + */ > + > +#define HOST_REQUEST_FLAG 1 /* Host request flag, according to > + * OTG and EH 2.0 Charpter 6.2.3 > + * Table:6-5 > + */ > + > +#define T_HOST_REQ_POLL (1500) /* 1500ms, HNP polling interval */ > + > enum otg_fsm_timer { > /* Standard OTG timers */ > A_WAIT_VRISE, > @@ -119,6 +131,7 @@ struct otg_fsm { > /* Current usb protocol used: 0:undefine; 1:host; 2:client */ > int protocol; > struct mutex lock; > + struct delayed_work hnp_polling_work; > }; > > struct otg_fsm_ops { > -- > 1.7.9.5 > -- Best Regards, Peter Chen -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html