From: Li Jun <b47624@xxxxxxxxxxxxx>
This patch adds OTG status selector request sending function, can be used
to poll peripheral if it wants to be host after OTG port is in host state.
Signed-off-by: Li Jun <b47624@xxxxxxxxxxxxx>
---
drivers/usb/common/usb-otg-fsm.c | 55 ++++++++++++++++++++++++++++++++++++++
include/linux/usb/otg-fsm.h | 9 +++++++
2 files changed, 64 insertions(+)
diff --git a/drivers/usb/common/usb-otg-fsm.c b/drivers/usb/common/usb-otg-fsm.c
index 141c8d7..384cdaf 100644
--- a/drivers/usb/common/usb-otg-fsm.c
+++ b/drivers/usb/common/usb-otg-fsm.c
@@ -366,3 +366,58 @@ int otg_statemachine(struct otg_fsm *fsm)
return state_changed;
}
EXPORT_SYMBOL_GPL(otg_statemachine);
+
+/*
+ * Called by host to poll peripheral if it wants to be host after OTG port
+ * is in host state.
+ * return host request flag if success, otherwise error code.
+ */
+int otg_hnp_polling(struct otg_fsm *fsm)
+{
+ struct usb_device *udev;
+ u8 host_req_flag;
+ int retval;
+ enum usb_otg_state state = fsm->otg->phy->state;
+
+ if (state != OTG_STATE_A_HOST && state != OTG_STATE_B_HOST)
+ return -EINVAL;
+
+ 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 -ENODEV;
+ }
+
+ /* 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) {
+ if (host_req_flag == HOST_REQUEST_FLAG) {
+ if (state == OTG_STATE_A_HOST)
+ fsm->a_bus_req = 0;
+ else if (state == OTG_STATE_B_HOST)
+ fsm->b_bus_req = 0;
+ retval = HOST_REQUEST_FLAG;
+ } else if (host_req_flag == 0) {
+ /* Continue polling */
+ otg_add_timer(fsm, HNP_POLLING);
+ retval = 0;
+ } else {
+ dev_err(&udev->dev, "host request flag is invalid\n");
+ retval = -EINVAL;
+ }
+ } else {
+ dev_err(&udev->dev, "Get one byte OTG status failed\n");
+ retval = -EIO;
+ }
+ return retval;
+}
+EXPORT_SYMBOL_GPL(otg_hnp_polling);
diff --git a/include/linux/usb/otg-fsm.h b/include/linux/usb/otg-fsm.h
index c1da7c5..6d3514f 100644
--- a/include/linux/usb/otg-fsm.h
+++ b/include/linux/usb/otg-fsm.h
@@ -40,6 +40,14 @@
#define PROTO_HOST (1)
#define PROTO_GADGET (2)
+#define OTG_STS_SELECTOR 0xF000 /* OTG status selector, according to
+ * OTG and EH 2.0 Charpter 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
+ */
enum otg_fsm_timer {
/* Standard OTG timers */
A_WAIT_VRISE,
@@ -240,6 +248,7 @@ static inline int otg_start_gadget(struct otg_fsm *fsm, int on)
return fsm->ops->start_gadget(fsm, on);
}
+int otg_hnp_polling(struct otg_fsm *fsm);
int otg_statemachine(struct otg_fsm *fsm);
#endif /* __LINUX_USB_OTG_FSM_H */
--
1.7.9.5
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