On Wed, May 28, 2014 at 03:08:19PM +0800, Li Jun wrote:
> 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.
You may just need to mention adding hnp polling API, and the usage of this
API.
>
> 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.
> + */
In fact, it has three return value.
> +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
>
--
Best Regards,
Peter Chen
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