From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752910AbcBHM0d (ORCPT ); Mon, 8 Feb 2016 07:26:33 -0500 Received: from mailout1.w1.samsung.com ([210.118.77.11]:46329 "EHLO mailout1.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751519AbcBHM0c (ORCPT ); Mon, 8 Feb 2016 07:26:32 -0500 X-AuditID: cbfec7f5-f79b16d000005389-e2-56b88975b9a1 From: Marek Szyprowski To: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Marek Szyprowski , Ruslan Bilovol , Bartlomiej Zolnierkiewicz , Vegard Nossum , Maxime Ripard , Greg Kroah-Hartman , Peter Chen , Felipe Balbi Subject: [PATCH v2] usb: gadget: provide interface for legacy gadgets to get UDC name Date: Mon, 08 Feb 2016 13:26:18 +0100 Message-id: <1454934378-2563-1-git-send-email-m.szyprowski@samsung.com> X-Mailer: git-send-email 1.9.2 In-reply-to: <56B87C8A.6090609@oracle.com> References: <56B87C8A.6090609@oracle.com> X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFlrHLMWRmVeSWpSXmKPExsVy+t/xq7qlnTvCDE4flbDYOGM9q8Wxtifs Fs2L17NZXN41h81i0bJWZou1R+6yW2zdtJfZ4tjsv0wWPTtPMFqcbVrD6sDl8WTTRUaPf4f7 mTx2zrrL7rFpVSebx/65a9g9Pj69xeLRt2UVo8fnTXIBHFFcNimpOZllqUX6dglcGfe3dTIV XFGpeL0zv4Fxp1wXIyeHhICJxO1335khbDGJC/fWs3UxcnEICSxllHiyaDFYQkigiUni6Gwf EJtNwFCi620XUBEHh4iAtUTfwSCQemaBj0wSHXMnMIHUCAuESyze18QOYrMIqEp8/v8ezOYV cJe4cWEzI8QyOYn/L1cwgczhFNCSWPBTA8QUEtCUWNwoMYGRdwEjwypG0dTS5ILipPRcI73i xNzi0rx0veT83E2MkFD8uoNx6TGrQ4wCHIxKPLwKbdvDhFgTy4orcw8xSnAwK4nw+jTsCBPi TUmsrEotyo8vKs1JLT7EKM3BoiTOO3PX+xAhgfTEktTs1NSC1CKYLBMHp1QD48VsGc/9ZlMX 6q6s9yr8X7LJo0djbTrzttKqXaeEzZdqVUt/vSjmd8tn3r0q5ZBPvzSU376p2qizVn5/+Zl9 F3d57p553ztoddiivlLlYsk1TXu6Itu3uZpl7lCbsHP/ykAfpzrD9y7Pdj8y/LVirli5wNWH az9taj7J+Ik9+WbAZkUb+ReW65RYijMSDbWYi4oTAYqSDwRBAgAA Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Since commit 855ed04a3758b205e84b269f92d26ab36ed8e2f7 ("usb: gadget: udc-core: independent registration of gadgets and gadget drivers") gadget drivers can not assume that UDC drivers are already available on their initialization. This broke the HACK, which was used in gadgetfs driver, to get UDC controller name. This patch removes this hack and replaces it by additional function in the UDC core (which is usefully only for legacy drivers, please don't use it in the new code). Reported-by: Vegard Nossum Signed-off-by: Marek Szyprowski --- changelog: v2: - properly report udc gagdet driver name instead of udc device name v1: https://lkml.org/lkml/2016/2/8/176 - initial version --- drivers/usb/gadget/legacy/inode.c | 29 ++--------------------------- drivers/usb/gadget/udc/udc-core.c | 33 +++++++++++++++++++++++++++++++++ include/linux/usb/gadget.h | 1 + 3 files changed, 36 insertions(+), 27 deletions(-) diff --git a/drivers/usb/gadget/legacy/inode.c b/drivers/usb/gadget/legacy/inode.c index 7e179f81d05c..7a62a2f7bc18 100644 --- a/drivers/usb/gadget/legacy/inode.c +++ b/drivers/usb/gadget/legacy/inode.c @@ -227,7 +227,7 @@ static void put_ep (struct ep_data *data) * implicitly, starting with the driver name and then endpoint names. */ -static const char *CHIP; +static char CHIP[32]; /*----------------------------------------------------------------------*/ @@ -1697,28 +1697,6 @@ static struct usb_gadget_driver gadgetfs_driver = { }; /*----------------------------------------------------------------------*/ - -static void gadgetfs_nop(struct usb_gadget *arg) { } - -static int gadgetfs_probe(struct usb_gadget *gadget, - struct usb_gadget_driver *driver) -{ - CHIP = gadget->name; - return -EISNAM; -} - -static struct usb_gadget_driver probe_driver = { - .max_speed = USB_SPEED_HIGH, - .bind = gadgetfs_probe, - .unbind = gadgetfs_nop, - .setup = (void *)gadgetfs_nop, - .disconnect = gadgetfs_nop, - .driver = { - .name = "nop", - }, -}; - - /* DEVICE INITIALIZATION * * fd = open ("/dev/gadget/$CHIP", O_RDWR) @@ -1968,10 +1946,7 @@ gadgetfs_fill_super (struct super_block *sb, void *opts, int silent) if (the_device) return -ESRCH; - /* fake probe to determine $CHIP */ - CHIP = NULL; - usb_gadget_probe_driver(&probe_driver); - if (!CHIP) + if (usb_get_gadget_udc_name(CHIP, sizeof(CHIP)) != 0) return -ENODEV; /* superblock */ diff --git a/drivers/usb/gadget/udc/udc-core.c b/drivers/usb/gadget/udc/udc-core.c index fd73a3ea07c2..4bde2e110e44 100644 --- a/drivers/usb/gadget/udc/udc-core.c +++ b/drivers/usb/gadget/udc/udc-core.c @@ -442,6 +442,39 @@ err1: EXPORT_SYMBOL_GPL(usb_add_gadget_udc_release); /** + * usb_get_gadget_udc_name - get the name of the first UDC controller + * @dst_name + * @len + * This functions returns the name of the first UDC controller in the system. + * Please note that this interface is usefull only for legacy drivers which + * assume that there is only one UDC controller in the system and they need to + * get its name before initialization. There is no guarantee that the UDC + * of the returned name will be still available, when gadget driver registers + * itself. + * + * Returns zero on success, negative errno otherwise. + */ +int usb_get_gadget_udc_name(char *dst_name, int len) +{ + struct usb_udc *udc; + int ret = -ENODEV; + + mutex_lock(&udc_lock); + list_for_each_entry(udc, &udc_list, list) { + const char *name = udc->gadget->name; + /* For now we take the first one */ + if (!udc->driver && strlen(name) + 1 <= len) { + strcpy(dst_name, name); + ret = 0; + break; + } + } + mutex_unlock(&udc_lock); + return ret; +} +EXPORT_SYMBOL_GPL(usb_get_gadget_udc_name); + +/** * usb_add_gadget_udc - adds a new gadget to the udc class driver list * @parent: the parent device to this udc. Usually the controller * driver's device. diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h index d82d0068872b..0a8f08302a34 100644 --- a/include/linux/usb/gadget.h +++ b/include/linux/usb/gadget.h @@ -1126,6 +1126,7 @@ 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 int usb_get_gadget_udc_name(char *dst_name, int len); /*-------------------------------------------------------------------------*/ -- 1.9.2