From f2adc4f8aaf272de9ac71dcb18d95ebe05fc3f94 Mon Sep 17 00:00:00 2001 From: Michal Nazarewicz Date: Wed, 16 Jun 2010 12:07:59 +0200 Subject: [PATCH] USB: gadget: composite: usb_string_ids_*() functions added usb_string_ids_tab() and usb_string_ids_n() functions added to the composite framework. The first accepts an array of usb_string object and for each registeres a string id and the second registeres a given number of ids and returns the first. This may simplify string ids registration since gadgets and composite functions won't have to call usb_string_id() several times and each time check for errer status -- all this will be done with a single call. Signed-off-by: Michal Nazarewicz Signed-off-by: Kyungmin Park Signed-off-by: Greg Kroah-Hartman --- drivers/usb/gadget/composite.c | 71 ++++++++++++++++++++++++++++++++-- include/linux/usb/composite.h | 4 ++ 2 files changed, 71 insertions(+), 4 deletions(-) diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c index 391d169f8d07..125167e17ce5 100644 --- a/drivers/usb/gadget/composite.c +++ b/drivers/usb/gadget/composite.c @@ -673,20 +673,83 @@ static int get_string(struct usb_composite_dev *cdev, * string IDs. Drivers for functions, configurations, or gadgets will * then store that ID in the appropriate descriptors and string table. * - * All string identifier should be allocated using this routine, to - * ensure that for example different functions don't wrongly assign - * different meanings to the same identifier. + * All string identifier should be allocated using this, + * @usb_string_ids_tab() or @usb_string_ids_n() routine, to ensure + * that for example different functions don't wrongly assign different + * meanings to the same identifier. */ int usb_string_id(struct usb_composite_dev *cdev) { if (cdev->next_string_id < 254) { - /* string id 0 is reserved */ + /* string id 0 is reserved by USB spec for list of + * supported languages */ + /* 255 reserved as well? -- mina86 */ cdev->next_string_id++; return cdev->next_string_id; } return -ENODEV; } +/** + * usb_string_ids() - allocate unused string IDs in batch + * @cdev: the device whose string descriptor IDs are being allocated + * @str: an array of usb_string objects to assign numbers to + * Context: single threaded during gadget setup + * + * @usb_string_ids() is called from bind() callbacks to allocate + * string IDs. Drivers for functions, configurations, or gadgets will + * then copy IDs from the string table to the appropriate descriptors + * and string table for other languages. + * + * All string identifier should be allocated using this, + * @usb_string_id() or @usb_string_ids_n() routine, to ensure that for + * example different functions don't wrongly assign different meanings + * to the same identifier. + */ +int usb_string_ids_tab(struct usb_composite_dev *cdev, struct usb_string *str) +{ + int next = cdev->next_string_id; + + for (; str->s; ++str) { + if (unlikely(next >= 254)) + return -ENODEV; + str->id = ++next; + } + + cdev->next_string_id = next; + + return 0; +} + +/** + * usb_string_ids_n() - allocate unused string IDs in batch + * @cdev: the device whose string descriptor IDs are being allocated + * @n: number of string IDs to allocate + * Context: single threaded during gadget setup + * + * Returns the first requested ID. This ID and next @n-1 IDs are now + * valid IDs. At least providind that @n is non zore because if it + * is, returns last requested ID which is now very useful information. + * + * @usb_string_ids_n() is called from bind() callbacks to allocate + * string IDs. Drivers for functions, configurations, or gadgets will + * then store that ID in the appropriate descriptors and string table. + * + * All string identifier should be allocated using this, + * @usb_string_id() or @usb_string_ids_n() routine, to ensure that for + * example different functions don't wrongly assign different meanings + * to the same identifier. + */ +int usb_string_ids_n(struct usb_composite_dev *c, unsigned n) +{ + unsigned next = c->next_string_id; + if (unlikely(n > 254 || (unsigned)next + n > 254)) + return -ENODEV; + c->next_string_id += n; + return next + 1; +} + + /*-------------------------------------------------------------------------*/ static void composite_setup_complete(struct usb_ep *ep, struct usb_request *req) diff --git a/include/linux/usb/composite.h b/include/linux/usb/composite.h index 139353efad34..f378075c839a 100644 --- a/include/linux/usb/composite.h +++ b/include/linux/usb/composite.h @@ -342,6 +342,10 @@ struct usb_composite_dev { }; extern int usb_string_id(struct usb_composite_dev *c); +extern int usb_string_ids_tab(struct usb_composite_dev *c, + struct usb_string *str); +extern int usb_string_ids_n(struct usb_composite_dev *c, unsigned n); + /* messaging utils */ #define DBG(d, fmt, args...) \ -- 2.20.1