From 3301c215a2bb94b5a0afcb444bbe9bf2a395a65d Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Fri, 21 Aug 2020 10:55:44 +0800 Subject: [PATCH] USB: UDC: Expand device model API interface The routines used by the UDC core to interface with the kernel's device model, namely usb_add_gadget_udc(), usb_add_gadget_udc_release(), and usb_del_gadget_udc(), provide access to only a subset of the device model's full API. They include functionality equivalent to device_register() and device_unregister() for gadgets, but they omit device_initialize(), device_add(), device_del(), get_device(), and put_device(). This patch expands the UDC API by adding usb_initialize_gadget(), usb_add_gadget(), usb_del_gadget(), usb_get_gadget(), and usb_put_gadget() to fill in the gap. It rewrites the existing routines to call the new ones. CC: Anton Vasilyev CC: Evgeny Novikov CC: Benjamin Herrenschmidt Reviewed-by: Greg Kroah-Hartman Signed-off-by: Alan Stern Signed-off-by: Peter Chen Signed-off-by: Felipe Balbi --- drivers/usb/gadget/udc/core.c | 78 ++++++++++++++++++++++++++++++++++--------- include/linux/usb/gadget.h | 27 +++++++++++---- 2 files changed, 84 insertions(+), 21 deletions(-) diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c index 4f82bcd3..2b6770d 100644 --- a/drivers/usb/gadget/udc/core.c +++ b/drivers/usb/gadget/udc/core.c @@ -1164,21 +1164,18 @@ static int check_pending_gadget_drivers(struct usb_udc *udc) } /** - * usb_add_gadget_udc_release - adds a new gadget to the udc class driver list + * usb_initialize_gadget - initialize a gadget and its embedded struct device * @parent: the parent device to this udc. Usually the controller driver's * device. - * @gadget: the gadget to be added to the list. + * @gadget: the gadget to be initialized. * @release: a gadget release function. * * Returns zero on success, negative errno otherwise. * Calls the gadget release function in the latter case. */ -int usb_add_gadget_udc_release(struct device *parent, struct usb_gadget *gadget, +void usb_initialize_gadget(struct device *parent, struct usb_gadget *gadget, void (*release)(struct device *dev)) { - struct usb_udc *udc; - int ret = -ENOMEM; - dev_set_name(&gadget->dev, "gadget"); INIT_WORK(&gadget->work, usb_gadget_state_work); gadget->dev.parent = parent; @@ -1189,17 +1186,32 @@ int usb_add_gadget_udc_release(struct device *parent, struct usb_gadget *gadget, gadget->dev.release = usb_udc_nop_release; device_initialize(&gadget->dev); +} +EXPORT_SYMBOL_GPL(usb_initialize_gadget); + +/** + * usb_add_gadget - adds a new gadget to the udc class driver list + * @gadget: the gadget to be added to the list. + * + * Returns zero on success, negative errno otherwise. + * Does not do a final usb_put_gadget() if an error occurs. + */ +int usb_add_gadget(struct usb_gadget *gadget) +{ + struct usb_udc *udc; + int ret = -ENOMEM; udc = kzalloc(sizeof(*udc), GFP_KERNEL); if (!udc) - goto err_put_gadget; + goto error; device_initialize(&udc->dev); udc->dev.release = usb_udc_release; udc->dev.class = udc_class; udc->dev.groups = usb_udc_attr_groups; - udc->dev.parent = parent; - ret = dev_set_name(&udc->dev, "%s", kobject_name(&parent->kobj)); + udc->dev.parent = gadget->dev.parent; + ret = dev_set_name(&udc->dev, "%s", + kobject_name(&gadget->dev.parent->kobj)); if (ret) goto err_put_udc; @@ -1242,8 +1254,30 @@ int usb_add_gadget_udc_release(struct device *parent, struct usb_gadget *gadget, err_put_udc: put_device(&udc->dev); - err_put_gadget: - put_device(&gadget->dev); + error: + return ret; +} +EXPORT_SYMBOL_GPL(usb_add_gadget); + +/** + * usb_add_gadget_udc_release - adds a new gadget to the udc class driver list + * @parent: the parent device to this udc. Usually the controller driver's + * device. + * @gadget: the gadget to be added to the list. + * @release: a gadget release function. + * + * Returns zero on success, negative errno otherwise. + * Calls the gadget release function in the latter case. + */ +int usb_add_gadget_udc_release(struct device *parent, struct usb_gadget *gadget, + void (*release)(struct device *dev)) +{ + int ret; + + usb_initialize_gadget(parent, gadget, release); + ret = usb_add_gadget(gadget); + if (ret) + usb_put_gadget(gadget); return ret; } EXPORT_SYMBOL_GPL(usb_add_gadget_udc_release); @@ -1311,13 +1345,14 @@ static void usb_gadget_remove_driver(struct usb_udc *udc) } /** - * usb_del_gadget_udc - deletes @udc from udc_list + * usb_del_gadget - deletes @udc from udc_list * @gadget: the gadget to be removed. * - * This, will call usb_gadget_unregister_driver() if + * This will call usb_gadget_unregister_driver() if * the @udc is still busy. + * It will not do a final usb_put_gadget(). */ -void usb_del_gadget_udc(struct usb_gadget *gadget) +void usb_del_gadget(struct usb_gadget *gadget) { struct usb_udc *udc = gadget->udc; @@ -1340,7 +1375,20 @@ void usb_del_gadget_udc(struct usb_gadget *gadget) kobject_uevent(&udc->dev.kobj, KOBJ_REMOVE); flush_work(&gadget->work); device_unregister(&udc->dev); - device_unregister(&gadget->dev); + device_del(&gadget->dev); +} +EXPORT_SYMBOL_GPL(usb_del_gadget); + +/** + * usb_del_gadget_udc - deletes @udc from udc_list + * @gadget: the gadget to be removed. + * + * Calls usb_del_gadget() and does a final usb_put_gadget(). + */ +void usb_del_gadget_udc(struct usb_gadget *gadget) +{ + usb_del_gadget(gadget); + usb_put_gadget(gadget); memset(&gadget->dev, 0x00, sizeof(gadget->dev)); } EXPORT_SYMBOL_GPL(usb_del_gadget_udc); diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h index 52ce1f6..e7351d6 100644 --- a/include/linux/usb/gadget.h +++ b/include/linux/usb/gadget.h @@ -436,6 +436,7 @@ struct usb_gadget { }; #define work_to_gadget(w) (container_of((w), struct usb_gadget, work)) +/* Interface to the device model */ static inline void set_gadget_data(struct usb_gadget *gadget, void *data) { dev_set_drvdata(&gadget->dev, data); } static inline void *get_gadget_data(struct usb_gadget *gadget) @@ -444,6 +445,26 @@ static inline struct usb_gadget *dev_to_usb_gadget(struct device *dev) { return container_of(dev, struct usb_gadget, dev); } +static inline struct usb_gadget *usb_get_gadget(struct usb_gadget *gadget) +{ + get_device(&gadget->dev); + return gadget; +} +static inline void usb_put_gadget(struct usb_gadget *gadget) +{ + put_device(&gadget->dev); +} +extern void usb_initialize_gadget(struct device *parent, + struct usb_gadget *gadget, void (*release)(struct device *dev)); +extern int usb_add_gadget(struct usb_gadget *gadget); +extern void usb_del_gadget(struct usb_gadget *gadget); + +/* Legacy device-model interface */ +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); +extern void usb_del_gadget_udc(struct usb_gadget *gadget); +extern char *usb_get_gadget_udc_name(void); /* iterates the non-control endpoints; 'tmp' is a struct usb_ep pointer */ #define gadget_for_each_ep(tmp, gadget) \ @@ -735,12 +756,6 @@ int usb_gadget_probe_driver(struct usb_gadget_driver *driver); */ int usb_gadget_unregister_driver(struct usb_gadget_driver *driver); -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); -extern void usb_del_gadget_udc(struct usb_gadget *gadget); -extern char *usb_get_gadget_udc_name(void); - /*-------------------------------------------------------------------------*/ /* utility to simplify dealing with string descriptors */ -- 2.7.4