On 21 June 2016 at 22:50, Felipe Balbi <balbi@xxxxxxxxxx> wrote: > > Hi, > > Baolin Wang <baolin.wang@xxxxxxxxxx> writes: >>>> This patch introduces the usb charger driver based on usb gadget that >>>> makes an enhancement to a power driver. It works well in practice but >>>> that requires a system with suitable hardware. >>>> >>>> The basic conception of the usb charger is that, when one usb charger >>>> is added or removed by reporting from the usb gadget state change or >>>> the extcon device state change, the usb charger will report to power >>>> user to set the current limitation. >>>> >>>> The usb charger will register notifiees on the usb gadget or the extcon >>>> device to get notified the usb charger state. It also supplies the >>>> notification mechanism to userspace When the usb charger state is changed. >>>> >>>> Power user will register a notifiee on the usb charger to get notified >>>> by status changes from the usb charger. It will report to power user >>>> to set the current limitation when detecting the usb charger is added >>>> or removed from extcon device state or usb gadget state. >>>> >>>> This patch doesn't yet integrate with the gadget code, so some functions >>>> which rely on the 'gadget' are not completed, that will be implemented >>>> in the following patches. >>>> >>>> Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxx> >>>> Reviewed-by: Li Jun <jun.li@xxxxxxx> >>>> Tested-by: Li Jun <jun.li@xxxxxxx> >>>> --- >>>> drivers/usb/gadget/Kconfig | 7 + >>>> drivers/usb/gadget/udc/Makefile | 1 + >>>> drivers/usb/gadget/udc/charger.c | 770 ++++++++++++++++++++++++++++++++++++++ >>>> include/linux/usb/charger.h | 191 ++++++++++ >>>> include/uapi/linux/usb/charger.h | 31 ++ >>>> 5 files changed, 1000 insertions(+) >>>> create mode 100644 drivers/usb/gadget/udc/charger.c >>>> create mode 100644 include/linux/usb/charger.h >>>> create mode 100644 include/uapi/linux/usb/charger.h >>>> >>>> diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig >>>> index 2057add..89f4e9b 100644 >>>> --- a/drivers/usb/gadget/Kconfig >>>> +++ b/drivers/usb/gadget/Kconfig >>>> @@ -134,6 +134,13 @@ config U_SERIAL_CONSOLE >>>> help >>>> It supports the serial gadget can be used as a console. >>>> >>>> +config USB_CHARGER >>>> + bool "USB charger support" >>> >>> you didn't build test all possibilities, did you? >>> >>> I have a feeling this won't link if USB_GADGET=m. Can you test that? >> >> OK. >> >>> >>>> diff --git a/drivers/usb/gadget/udc/charger.c b/drivers/usb/gadget/udc/charger.c >>> [...] >>>> +struct class *usb_charger_class; >>> >>> We already have a UDC class, do we really, really need another class >>> here? >> >> We want to manage the usb charger devices by this class and one usb >> charger device is not equal with one usb device which managed by UDC > > Can you explain this statement? If charging is done via a USB peripheral > port, why don't we have a 1:1 mapping between charger and UDC? Sorry for confusing, but forget it, I plan to remove the device/class things as you suggested. > >> class, so can we use UDC class to manage charger devices? >> By the way, you also suggested to use the 'class' things instead of >> 'bus' in previous mail. > > true, I did say that. It seems clearer, however, that we don't need this > virtual device here. OK. > >>>> +subsys_initcall(usb_charger_class_init); >>> >>> this should always work as module_init(). Please make sure that's the >>> case. >> >> we should make sure the charger class has been allocated before user >> try to add a new gadget to the udc class. So it should be issued >> before 'module_init()' (many usb drivers are at module_init level). > > -EPROBE_DEFER? OK. But 'EPROBE_DEFER' is not needed if we remove the class things. -- Baolin.wang Best Regards -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
