Re: [PATCH v17 3/4] usb: gadget: Integrate with the usb gadget supporting for usb charger

From: Baolin Wang
Date: Tue Oct 11 2016 - 00:08:06 EST


Hi Baolu,

On 11 October 2016 at 11:06, Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx> wrote:
> Hi,
>
> On 10/10/2016 02:22 PM, Baolin Wang wrote:
>> When the usb gadget supporting for usb charger is ready, the usb charger
>> can implement the usb_charger_plug_by_gadget() function, usb_charger_exit()
>> function and dev_to_uchger() function by getting 'struct usb_charger' from
>> 'struct gadget'.
>>
>> 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/udc/charger.c | 97 +++++++++++++++++++++++++++++++++++++-
>> 1 file changed, 95 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/usb/gadget/udc/charger.c b/drivers/usb/gadget/udc/charger.c
>> index 16dc477..691cd75 100644
>> --- a/drivers/usb/gadget/udc/charger.c
>> +++ b/drivers/usb/gadget/udc/charger.c
>> @@ -38,7 +38,9 @@ static DEFINE_MUTEX(charger_lock);
>>
>> static struct usb_charger *dev_to_uchger(struct device *dev)
>> {
>> - return NULL;
>> + struct usb_gadget *gadget = container_of(dev, struct usb_gadget, dev);
>> +
>> + return gadget->charger;
>> }
>>
>> /*
>> @@ -308,6 +310,18 @@ static int __usb_charger_set_cur_limit_by_type(struct usb_charger *uchger,
>> int usb_charger_set_cur_limit_by_gadget(struct usb_gadget *gadget,
>> unsigned int cur_limit)
>> {
>> + struct usb_charger *uchger = gadget->charger;
>> + int ret;
>> +
>> + if (!uchger)
>> + return -EINVAL;
>> +
>> + ret = __usb_charger_set_cur_limit_by_type(uchger, uchger->type,
>> + cur_limit);
>> + if (ret)
>> + return ret;
>> +
>> + schedule_work(&uchger->work);
>> return 0;
>> }
>> EXPORT_SYMBOL_GPL(usb_charger_set_cur_limit_by_gadget);
>> @@ -625,11 +639,67 @@ static int usb_charger_plug_by_extcon(struct notifier_block *nb,
>> int usb_charger_plug_by_gadget(struct usb_gadget *gadget,
>> unsigned long state)
>> {
>> + struct usb_charger *uchger = gadget->charger;
>> + enum usb_charger_state uchger_state;
>> +
>> + if (WARN(!uchger, "charger can not be NULL"))
>> + return -EINVAL;
>> +
>> + /*
>> + * Report event to power to setting the current limitation
>> + * for this usb charger when one usb charger state is changed
>> + * with detecting by usb gadget state.
>> + */
>> + if (uchger->old_gadget_state != state) {
>> + uchger->old_gadget_state = state;
>> +
>> + if (state >= USB_STATE_ATTACHED) {
>> + uchger_state = USB_CHARGER_PRESENT;
>> + } else if (state == USB_STATE_NOTATTACHED) {
>> + mutex_lock(&uchger->lock);
>> +
>> + /*
>> + * Need check the charger type to make sure the usb
>> + * cable is removed, in case it just changes the usb
>> + * function with configfs.
>> + */
>> + uchger->type = __usb_charger_get_type(uchger);
>> + if (uchger->type != UNKNOWN_TYPE) {
>> + mutex_unlock(&uchger->lock);
>> + return 0;
>> + }
>> +
>> + mutex_unlock(&uchger->lock);
>> + uchger_state = USB_CHARGER_REMOVE;
>> + } else {
>> + uchger_state = USB_CHARGER_DEFAULT;
>> + }
>> +
>> + usb_charger_notify_state(uchger, uchger_state);
>> + }
>> +
>> return 0;
>> }
>> EXPORT_SYMBOL_GPL(usb_charger_plug_by_gadget);
>>
>> /*
>> + * usb_charger_unregister() - Unregister a usb charger.
>> + * @uchger - the usb charger to be unregistered.
>> + */
>> +static int usb_charger_unregister(struct usb_charger *uchger)
>> +{
>> + ida_simple_remove(&usb_charger_ida, uchger->id);
>> + sysfs_remove_groups(&uchger->gadget->dev.kobj, usb_charger_groups);
>> +
>> + mutex_lock(&charger_lock);
>> + list_del(&uchger->list);
>> + mutex_unlock(&charger_lock);
>> +
>> + kfree(uchger);
>
> Any reasons you want to put kfree() here? You allocated the memory
> in usb_charger_init(). Isn't usb_charger_exit() a better place?

The usb_charger_exit() will issue usb_charger_unregister() and we need
use the usb_charger structure in usb_charger_unregister() to
unregister the usb charger.

>
> Best regards,
> Lu Baolu
>
>> + return 0;
>> +}
>> +
>> +/*
>> * usb_charger_register() - Register a new usb charger.
>> * @uchger - the new usb charger instance.
>> */
>> @@ -740,6 +810,7 @@ int usb_charger_init(struct usb_gadget *ugadget)
>> }
>>
>> uchger->gadget = ugadget;
>> + ugadget->charger = uchger;
>> uchger->old_gadget_state = USB_STATE_NOTATTACHED;
>>
>> /* Register a new usb charger */
>> @@ -777,7 +848,29 @@ fail_extcon:
>>
>> int usb_charger_exit(struct usb_gadget *ugadget)
>> {
>> - return 0;
>> + struct usb_charger *uchger = ugadget->charger;
>> +
>> + if (!uchger)
>> + return -EINVAL;
>> +
>> + ugadget->charger = NULL;
>> + extcon_unregister_notifier(uchger->extcon_dev,
>> + EXTCON_USB,
>> + &uchger->extcon_nb.nb);
>> + extcon_unregister_notifier(uchger->extcon_dev,
>> + EXTCON_CHG_USB_SDP,
>> + &uchger->extcon_type_nb.nb);
>> + extcon_unregister_notifier(uchger->extcon_dev,
>> + EXTCON_CHG_USB_CDP,
>> + &uchger->extcon_type_nb.nb);
>> + extcon_unregister_notifier(uchger->extcon_dev,
>> + EXTCON_CHG_USB_DCP,
>> + &uchger->extcon_type_nb.nb);
>> + extcon_unregister_notifier(uchger->extcon_dev,
>> + EXTCON_CHG_USB_ACA,
>> + &uchger->extcon_type_nb.nb);
>> +
>> + return usb_charger_unregister(uchger);
>> }
>>
>> MODULE_AUTHOR("Baolin Wang <baolin.wang@xxxxxxxxxx>");
>



--
Baolin.wang
Best Regards