diff options
Diffstat (limited to 'drivers/usb/gadget/config.c')
| -rw-r--r-- | drivers/usb/gadget/config.c | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/drivers/usb/gadget/config.c b/drivers/usb/gadget/config.c new file mode 100644 index 0000000000..cf22629b97 --- /dev/null +++ b/drivers/usb/gadget/config.c @@ -0,0 +1,119 @@ +/* + * usb/gadget/config.c -- simplify building config descriptors + * + * Copyright (C) 2003 David Brownell + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Ported to U-boot by: Thomas Smits <ts.smits@gmail.com> and + * Remy Bohmer <linux@bohmer.net> + */ + +#include <common.h> +#include <asm/errno.h> +#include <linux/list.h> +#include <linux/string.h> + +#include <linux/usb/ch9.h> +#include <linux/usb/gadget.h> + + +/** + * usb_descriptor_fillbuf - fill buffer with descriptors + * @buf: Buffer to be filled + * @buflen: Size of buf + * @src: Array of descriptor pointers, terminated by null pointer. + * + * Copies descriptors into the buffer, returning the length or a + * negative error code if they can't all be copied. Useful when + * assembling descriptors for an associated set of interfaces used + * as part of configuring a composite device; or in other cases where + * sets of descriptors need to be marshaled. + */ +int +usb_descriptor_fillbuf(void *buf, unsigned buflen, + const struct usb_descriptor_header **src) +{ + u8 *dest = buf; + + if (!src) + return -EINVAL; + + /* fill buffer from src[] until null descriptor ptr */ + for (; NULL != *src; src++) { + unsigned len = (*src)->bLength; + + if (len > buflen) + return -EINVAL; + memcpy(dest, *src, len); + buflen -= len; + dest += len; + } + return dest - (u8 *)buf; +} + + +/** + * usb_gadget_config_buf - builts a complete configuration descriptor + * @config: Header for the descriptor, including characteristics such + * as power requirements and number of interfaces. + * @desc: Null-terminated vector of pointers to the descriptors (interface, + * endpoint, etc) defining all functions in this device configuration. + * @buf: Buffer for the resulting configuration descriptor. + * @length: Length of buffer. If this is not big enough to hold the + * entire configuration descriptor, an error code will be returned. + * + * This copies descriptors into the response buffer, building a descriptor + * for that configuration. It returns the buffer length or a negative + * status code. The config.wTotalLength field is set to match the length + * of the result, but other descriptor fields (including power usage and + * interface count) must be set by the caller. + * + * Gadget drivers could use this when constructing a config descriptor + * in response to USB_REQ_GET_DESCRIPTOR. They will need to patch the + * resulting bDescriptorType value if USB_DT_OTHER_SPEED_CONFIG is needed. + */ +int usb_gadget_config_buf( + const struct usb_config_descriptor *config, + void *buf, + unsigned length, + const struct usb_descriptor_header **desc +) +{ + struct usb_config_descriptor *cp = buf; + int len; + + /* config descriptor first */ + if (length < USB_DT_CONFIG_SIZE || !desc) + return -EINVAL; + *cp = *config; + + /* then interface/endpoint/class/vendor/... */ + len = usb_descriptor_fillbuf(USB_DT_CONFIG_SIZE + (u8 *)buf, + length - USB_DT_CONFIG_SIZE, desc); + if (len < 0) + return len; + len += USB_DT_CONFIG_SIZE; + if (len > 0xffff) + return -EINVAL; + + /* patch up the config descriptor */ + cp->bLength = USB_DT_CONFIG_SIZE; + cp->bDescriptorType = USB_DT_CONFIG; + cp->wTotalLength = cpu_to_le16(len); + cp->bmAttributes |= USB_CONFIG_ATT_ONE; + return len; +} + |