lkml.org 
[lkml]   [2015]   [Apr]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [RFC][PATCH v2 04/13] usb: gadget: add usb_gadget_start/stop()
On 16/04/15 14:48, Peter Chen wrote:
> On Tue, Apr 14, 2015 at 01:41:51PM +0300, Roger Quadros wrote:
>> The OTG state machine needs a mechanism to start and
>> stop the gadget controller. Add usb_gadget_start()
>> and usb_gadget_stop().
>>
>> Signed-off-by: Roger Quadros <rogerq@ti.com>
>> ---
>> drivers/usb/gadget/udc/udc-core.c | 74 +++++++++++++++++++++++++++++++++++++++
>> include/linux/usb/gadget.h | 3 ++
>> 2 files changed, 77 insertions(+)
>>
>> diff --git a/drivers/usb/gadget/udc/udc-core.c b/drivers/usb/gadget/udc/udc-core.c
>> index 5a81cb0..3aa5dd5 100644
>> --- a/drivers/usb/gadget/udc/udc-core.c
>> +++ b/drivers/usb/gadget/udc/udc-core.c
>> @@ -187,6 +187,7 @@ EXPORT_SYMBOL_GPL(usb_gadget_udc_reset);
>> */
>> static inline int usb_gadget_udc_start(struct usb_udc *udc)
>> {
>> + dev_dbg(&udc->dev, "%s\n", __func__);
>> return udc->gadget->ops->udc_start(udc->gadget, udc->driver);
>> }
>>
>> @@ -204,10 +205,83 @@ static inline int usb_gadget_udc_start(struct usb_udc *udc)
>> */
>> static inline void usb_gadget_udc_stop(struct usb_udc *udc)
>> {
>> + dev_dbg(&udc->dev, "%s\n", __func__);
>> udc->gadget->ops->udc_stop(udc->gadget);
>> }
>>
>> /**
>> + * usb_gadget_start - start the usb gadget controller and connect to bus
>> + * @gadget: the gadget device to start
>> + *
>> + * This is external API for use by OTG core.
>> + *
>> + * Start the usb device controller and connect to bus (enable pull).
>> + */
>> +int usb_gadget_start(struct usb_gadget *gadget)
>> +{
>> + int ret;
>> + struct usb_udc *udc = NULL;
>> +
>> + dev_dbg(&gadget->dev, "%s\n", __func__);
>> + mutex_lock(&udc_lock);
>> + list_for_each_entry(udc, &udc_list, list)
>> + if (udc->gadget == gadget)
>> + goto found;
>> +
>> + dev_err(gadget->dev.parent, "%s: gadget not registered.\n",
>> + __func__);
>> + mutex_unlock(&udc_lock);
>> + return -EINVAL;
>> +
>> +found:
>> + ret = usb_gadget_udc_start(udc);
>> + if (ret)
>> + dev_err(&udc->dev, "USB Device Controller didn't start: %d\n",
>> + ret);
>> + else
>> + usb_gadget_connect(udc->gadget);
>
> OTG FSM manages its pullup/pulldown itself through its fsm->ops->loc_conn

That API usb_gadget_udc_start() is used by DRD (dual-role) FSM as well
and it doesn't use ops->loc_conn. So i'm wondering how to make this work for
both.

I could probably remove the pull up control from usb_gadget_start/stop()
and move it into the DRD FSM.

cheers,
-roger

>
>> +
>> + mutex_unlock(&udc_lock);
>> +
>> + return ret;
>> +}
>> +EXPORT_SYMBOL_GPL(usb_gadget_start);
>> +
>> +/**
>> + * usb_gadget_stop - disconnect from bus and stop the usb gadget
>> + * @gadget: The gadget device we want to stop
>> + *
>> + * This is external API for use by OTG core.
>> + *
>> + * Disconnect from the bus (disable pull) and stop the
>> + * gadget controller.
>> + */
>> +int usb_gadget_stop(struct usb_gadget *gadget)
>> +{
>> + struct usb_udc *udc = NULL;
>> +
>> + dev_dbg(&gadget->dev, "%s\n", __func__);
>> + mutex_lock(&udc_lock);
>> + list_for_each_entry(udc, &udc_list, list)
>> + if (udc->gadget == gadget)
>> + goto found;
>> +
>> + dev_err(gadget->dev.parent, "%s: gadget not registered.\n",
>> + __func__);
>> + mutex_unlock(&udc_lock);
>> + return -EINVAL;
>> +
>> +found:
>> + usb_gadget_disconnect(udc->gadget);
>> + udc->driver->disconnect(udc->gadget);
>> + usb_gadget_udc_stop(udc);
>> + mutex_unlock(&udc_lock);
>> +
>> + return 0;
>> +}
>> +EXPORT_SYMBOL_GPL(usb_gadget_stop);
>> +
>> +/**
>> * usb_udc_release - release the usb_udc struct
>> * @dev: the dev member within usb_udc
>> *
>> diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
>> index e2f00fd..7ada7e6 100644
>> --- a/include/linux/usb/gadget.h
>> +++ b/include/linux/usb/gadget.h
>> @@ -922,6 +922,9 @@ int usb_gadget_probe_driver(struct usb_gadget_driver *driver);
>> */
>> int usb_gadget_unregister_driver(struct usb_gadget_driver *driver);
>>
>> +int usb_gadget_start(struct usb_gadget *gadget);
>> +int usb_gadget_stop(struct usb_gadget *gadget);
>> +
>> extern int usb_add_gadget_udc_release(struct device *parent,
>> struct usb_gadget *gadget, void (*release)(struct device *dev));
>> extern int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget);
>> --
>> 2.1.0
>>
>



\
 
 \ /
  Last update: 2015-04-16 14:41    [W:0.074 / U:0.868 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site