From: Li Jun <b47624@xxxxxxxxxxxxx>
OTG in host mode call this function to poll peripheral if it wants to be host
role.
Signed-off-by: Li Jun <jun.li@xxxxxxxxxxxxx>
---
drivers/usb/common/usb-otg-fsm.c | 75 ++++++++++++++++++++++++++++++++++++++
include/linux/usb/otg-fsm.h | 10 +++++
2 files changed, 85 insertions(+)
diff --git a/drivers/usb/common/usb-otg-fsm.c b/drivers/usb/common/usb-otg-fsm.c
index 862eb04..1cd8995 100644
--- a/drivers/usb/common/usb-otg-fsm.c
+++ b/drivers/usb/common/usb-otg-fsm.c
@@ -367,3 +367,78 @@ int otg_statemachine(struct otg_fsm *fsm)
return state_changed;
}
EXPORT_SYMBOL_GPL(otg_statemachine);
+
+/*
+ * Called by host to poll if peripheral wants to be host
+ * Return value:
+ * - host request flag(1) if the device wants to be host;
+ * - host request flag(0) if the device keeps peripheral role;
+ * - 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->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) {
+ dev_err(&udev->dev, "Get one byte OTG status failed\n");
+ return -EIO;
+ }
+
+ if (host_req_flag == 0) {
+ /* Continue HNP polling */
+ otg_add_timer(fsm, HNP_POLLING);
+ return 0;
+ } else if (host_req_flag != HOST_REQUEST_FLAG) {
+ dev_err(&udev->dev, "host request flag is invalid\n");
+ return -EINVAL;
+ }
+
+ /* 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 -EINVAL;
+ }
+ fsm->otg->host->b_hnp_enable = 1;
+ }
+
+ fsm->a_bus_req = 0;
+ } else if (state == OTG_STATE_B_HOST) {
+ fsm->b_bus_req = 0;
+ }
+
+ return HOST_REQUEST_FLAG;
+}
+EXPORT_SYMBOL_GPL(otg_hnp_polling);
diff --git a/include/linux/usb/otg-fsm.h b/include/linux/usb/otg-fsm.h
index d1b3415..562f35b 100644
--- a/include/linux/usb/otg-fsm.h
+++ b/include/linux/usb/otg-fsm.h
@@ -40,6 +40,15 @@
#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,
@@ -243,5 +252,6 @@ static inline int otg_start_gadget(struct otg_fsm *fsm, int on)
}
int otg_statemachine(struct otg_fsm *fsm);
+int otg_hnp_polling(struct otg_fsm *fsm);
#endif /* __LINUX_USB_OTG_FSM_H */
--
1.7.9.5
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