On 20-11-14 00:12:46, Wesley Cheng wrote:
> Add a specific composite reset API to differentiate between disconnect and
> reset events. This is needed for adjusting the current draw accordingly
> based on the USB battery charging specification. The device is only allowed
> to draw the 500/900 mA (HS/SS) while in the CONFIGURED state, and only 100 mA
> in the connected and UNCONFIGURED state.
>
> Signed-off-by: Wesley Cheng <wcheng@xxxxxxxxxxxxxx>
Reviewed-by: Peter Chen <peter.chen@xxxxxxx>
Peter
> ---
> drivers/usb/gadget/composite.c | 21 +++++++++++++++++++--
> include/linux/usb/composite.h | 2 ++
> 2 files changed, 21 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
> index 05b176c82cc5..a41f7fe4b518 100644
> --- a/drivers/usb/gadget/composite.c
> +++ b/drivers/usb/gadget/composite.c
> @@ -2036,7 +2036,7 @@ composite_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
> return value;
> }
>
> -void composite_disconnect(struct usb_gadget *gadget)
> +static void __composite_disconnect(struct usb_gadget *gadget)
> {
> struct usb_composite_dev *cdev = get_gadget_data(gadget);
> unsigned long flags;
> @@ -2053,6 +2053,23 @@ void composite_disconnect(struct usb_gadget *gadget)
> spin_unlock_irqrestore(&cdev->lock, flags);
> }
>
> +void composite_disconnect(struct usb_gadget *gadget)
> +{
> + usb_gadget_vbus_draw(gadget, 0);
> + __composite_disconnect(gadget);
> +}
> +
> +void composite_reset(struct usb_gadget *gadget)
> +{
> + /*
> + * Section 1.4.13 Standard Downstream Port of the USB battery charging
> + * specification v1.2 states that a device connected on a SDP shall only
> + * draw at max 100mA while in a connected, but unconfigured state.
> + */
> + usb_gadget_vbus_draw(gadget, 100);
> + __composite_disconnect(gadget);
> +}
> +
> /*-------------------------------------------------------------------------*/
>
> static ssize_t suspended_show(struct device *dev, struct device_attribute *attr,
> @@ -2373,7 +2390,7 @@ static const struct usb_gadget_driver composite_driver_template = {
> .unbind = composite_unbind,
>
> .setup = composite_setup,
> - .reset = composite_disconnect,
> + .reset = composite_reset,
> .disconnect = composite_disconnect,
>
> .suspend = composite_suspend,
> diff --git a/include/linux/usb/composite.h b/include/linux/usb/composite.h
> index 2040696d75b6..0d8a71471512 100644
> --- a/include/linux/usb/composite.h
> +++ b/include/linux/usb/composite.h
> @@ -525,6 +525,8 @@ extern struct usb_string *usb_gstrings_attach(struct usb_composite_dev *cdev,
> extern int usb_string_ids_n(struct usb_composite_dev *c, unsigned n);
>
> extern void composite_disconnect(struct usb_gadget *gadget);
> +extern void composite_reset(struct usb_gadget *gadget);
> +
> extern int composite_setup(struct usb_gadget *gadget,
> const struct usb_ctrlrequest *ctrl);
> extern void composite_suspend(struct usb_gadget *gadget);
> --
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project
>
--
Thanks,
Peter Chen
