From de53c25447117eae6b3f8952f663f08a09e0dbb7 Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Sun, 23 Dec 2012 21:10:00 +0100 Subject: [PATCH] usb: gadget: add some infracture to register/unregister functions MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit This patch provides an infrastructure to register & unregister a USB function. This allows to turn a function into a module and avoid the '#include "f_.*.c"' magic and we get a clear API / cut between the bare gadget and its functions. The concept is simple: Each function defines the DECLARE_USB_FUNCTION_INIT macro whith an unique name of the function and two allocation functions. - one to create an "instance". The instance holds the current configuration set. In case there are two usb_configudations with one function there will be one instance and two usb_functions - one to create an "function" from the instance. The name of the instance is used to automaticaly load the module if it the instance is not yet available. The usb_function callbacks are slightly modified and extended: - usb_get_function() creates a struct usb_function inclunding all pointers (bind, unbind,…). It uses the "instance" to map its configuration. So we can have _two_ struct usb_function, one for each usb_configuration. - ->unbind() Since the struct usb_function was not allocated in ->bind() it should not kfree()d here. This function should only reverse what happens in ->bind() that is request cleanup and the cleanup of allocated descriptors. - ->free_func() a simple kfree() of the struct usb_function Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Felipe Balbi --- drivers/usb/gadget/Makefile | 2 +- drivers/usb/gadget/composite.c | 47 +++++++++++++++++++----------- include/linux/usb/composite.h | 52 ++++++++++++++++++++++++++++++++++ 3 files changed, 83 insertions(+), 18 deletions(-) diff --git a/drivers/usb/gadget/Makefile b/drivers/usb/gadget/Makefile index 8b4acfd92aa3..fef41f5d6e8d 100644 --- a/drivers/usb/gadget/Makefile +++ b/drivers/usb/gadget/Makefile @@ -6,7 +6,7 @@ ccflags-$(CONFIG_USB_GADGET_DEBUG) := -DDEBUG obj-$(CONFIG_USB_GADGET) += udc-core.o obj-$(CONFIG_USB_LIBCOMPOSITE) += libcomposite.o libcomposite-y := usbstring.o config.o epautoconf.o -libcomposite-y += composite.o +libcomposite-y += composite.o functions.o obj-$(CONFIG_USB_DUMMY_HCD) += dummy_hcd.o obj-$(CONFIG_USB_NET2272) += net2272.o obj-$(CONFIG_USB_NET2280) += net2280.o diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c index 9db000013f5d..4aa0e4652228 100644 --- a/drivers/usb/gadget/composite.c +++ b/drivers/usb/gadget/composite.c @@ -683,6 +683,31 @@ done: return result; } +int usb_add_config_only(struct usb_composite_dev *cdev, + struct usb_configuration *config) +{ + struct usb_configuration *c; + + if (!config->bConfigurationValue) + return -EINVAL; + + /* Prevent duplicate configuration identifiers */ + list_for_each_entry(c, &cdev->configs, list) { + if (c->bConfigurationValue == config->bConfigurationValue) + return -EBUSY; + } + + config->cdev = cdev; + list_add_tail(&config->list, &cdev->configs); + + INIT_LIST_HEAD(&config->functions); + config->next_interface_id = 0; + memset(config->interface, 0, sizeof(config->interface)); + + return 0; +} +EXPORT_SYMBOL_GPL(usb_add_config_only); + /** * usb_add_config() - add a configuration to a device. * @cdev: wraps the USB gadget @@ -703,30 +728,18 @@ int usb_add_config(struct usb_composite_dev *cdev, int (*bind)(struct usb_configuration *)) { int status = -EINVAL; - struct usb_configuration *c; + + if (!bind) + goto done; DBG(cdev, "adding config #%u '%s'/%p\n", config->bConfigurationValue, config->label, config); - if (!config->bConfigurationValue || !bind) + status = usb_add_config_only(cdev, config); + if (status) goto done; - /* Prevent duplicate configuration identifiers */ - list_for_each_entry(c, &cdev->configs, list) { - if (c->bConfigurationValue == config->bConfigurationValue) { - status = -EBUSY; - goto done; - } - } - - config->cdev = cdev; - list_add_tail(&config->list, &cdev->configs); - - INIT_LIST_HEAD(&config->functions); - config->next_interface_id = 0; - memset(config->interface, 0, sizeof(config->interface)); - status = bind(config); if (status < 0) { while (!list_empty(&config->functions)) { diff --git a/include/linux/usb/composite.h b/include/linux/usb/composite.h index dc512c9432d7..3834e3330b23 100644 --- a/include/linux/usb/composite.h +++ b/include/linux/usb/composite.h @@ -77,6 +77,8 @@ struct usb_configuration; * in interface or class descriptors; endpoints; I/O buffers; and so on. * @unbind: Reverses @bind; called as a side effect of unregistering the * driver which added this function. + * @free_func: free the struct usb_function. + * @mod: (internal) points to the module that created this structure. * @set_alt: (REQUIRED) Reconfigures altsettings; function drivers may * initialize usb_ep.driver data at this time (when it is used). * Note that setting an interface to its current altsetting resets @@ -116,6 +118,7 @@ struct usb_configuration; * two or more distinct instances within the same configuration, providing * several independent logical data links to a USB host. */ + struct usb_function { const char *name; struct usb_gadget_strings **strings; @@ -136,6 +139,8 @@ struct usb_function { struct usb_function *); void (*unbind)(struct usb_configuration *, struct usb_function *); + void (*free_func)(struct usb_function *f); + struct module *mod; /* runtime state management */ int (*set_alt)(struct usb_function *, @@ -432,6 +437,53 @@ static inline u16 get_default_bcdDevice(void) return bcdDevice; } +struct usb_function_driver { + const char *name; + struct module *mod; + struct list_head list; + struct usb_function_instance *(*alloc_inst)(void); + struct usb_function *(*alloc_func)(struct usb_function_instance *inst); +}; + +struct usb_function_instance { + struct usb_function_driver *fd; + void (*free_func_inst)(struct usb_function_instance *inst); +}; + +void usb_function_unregister(struct usb_function_driver *f); +int usb_function_register(struct usb_function_driver *newf); +void usb_put_function_instance(struct usb_function_instance *fi); +void usb_put_function(struct usb_function *f); +struct usb_function_instance *usb_get_function_instance(const char *name); +struct usb_function *usb_get_function(struct usb_function_instance *fi); + +struct usb_configuration *usb_get_config(struct usb_composite_dev *cdev, + int val); +int usb_add_config_only(struct usb_composite_dev *cdev, + struct usb_configuration *config); + +#define DECLARE_USB_FUNCTION(_name, _inst_alloc, _func_alloc) \ + static struct usb_function_driver _name ## usb_func = { \ + .name = __stringify(_name), \ + .mod = THIS_MODULE, \ + .alloc_inst = _inst_alloc, \ + .alloc_func = _func_alloc, \ + }; \ + MODULE_ALIAS("usbfunc:"__stringify(_name)); + +#define DECLARE_USB_FUNCTION_INIT(_name, _inst_alloc, _func_alloc) \ + DECLARE_USB_FUNCTION(_name, _inst_alloc, _func_alloc) \ + static int __init _name ## mod_init(void) \ + { \ + return usb_function_register(&_name ## usb_func); \ + } \ + static void __exit _name ## mod_exit(void) \ + { \ + usb_function_unregister(&_name ## usb_func); \ + } \ + module_init(_name ## mod_init); \ + module_exit(_name ## mod_exit) + /* messaging utils */ #define DBG(d, fmt, args...) \ dev_dbg(&(d)->gadget->dev , fmt , ## args) -- 2.20.1