diff options
Diffstat (limited to 'drivers/usb/gadget/config.c')
| -rw-r--r-- | drivers/usb/gadget/config.c | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/drivers/usb/gadget/config.c b/drivers/usb/gadget/config.c new file mode 100644 index 000000000..256364d4b --- /dev/null +++ b/drivers/usb/gadget/config.c @@ -0,0 +1,213 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * usb/gadget/config.c -- simplify building config descriptors + * + * Copyright (C) 2003 David Brownell + */ + +#include <linux/errno.h> +#include <linux/slab.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/list.h> +#include <linux/string.h> +#include <linux/device.h> + +#include <linux/usb/ch9.h> +#include <linux/usb/gadget.h> +#include <linux/usb/composite.h> +#include <linux/usb/otg.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; +} +EXPORT_SYMBOL_GPL(usb_descriptor_fillbuf); + +/** + * usb_copy_descriptors - copy a vector of USB descriptors + * @src: null-terminated vector to copy + * Context: initialization code, which may sleep + * + * This makes a copy of a vector of USB descriptors. Its primary use + * is to support usb_function objects which can have multiple copies, + * each needing different descriptors. Functions may have static + * tables of descriptors, which are used as templates and customized + * with identifiers (for interfaces, strings, endpoints, and more) + * as needed by a given function instance. + */ +struct usb_descriptor_header ** +usb_copy_descriptors(struct usb_descriptor_header **src) +{ + struct usb_descriptor_header **tmp; + unsigned bytes; + unsigned n_desc; + void *mem; + struct usb_descriptor_header **ret; + + /* count descriptors and their sizes; then add vector size */ + for (bytes = 0, n_desc = 0, tmp = src; *tmp; tmp++, n_desc++) + bytes += (*tmp)->bLength; + bytes += (n_desc + 1) * sizeof(*tmp); + + mem = kmalloc(bytes, GFP_KERNEL); + if (!mem) + return NULL; + + /* fill in pointers starting at "tmp", + * to descriptors copied starting at "mem"; + * and return "ret" + */ + tmp = mem; + ret = mem; + mem += (n_desc + 1) * sizeof(*tmp); + while (*src) { + memcpy(mem, *src, (*src)->bLength); + *tmp = mem; + tmp++; + mem += (*src)->bLength; + src++; + } + *tmp = NULL; + + return ret; +} +EXPORT_SYMBOL_GPL(usb_copy_descriptors); + +int usb_assign_descriptors(struct usb_function *f, + struct usb_descriptor_header **fs, + struct usb_descriptor_header **hs, + struct usb_descriptor_header **ss, + struct usb_descriptor_header **ssp) +{ + /* super-speed-plus descriptor falls back to super-speed one, + * if such a descriptor was provided, thus avoiding a NULL + * pointer dereference if a 5gbps capable gadget is used with + * a 10gbps capable config (device port + cable + host port) + */ + if (!ssp) + ssp = ss; + + if (fs) { + f->fs_descriptors = usb_copy_descriptors(fs); + if (!f->fs_descriptors) + goto err; + } + if (hs) { + f->hs_descriptors = usb_copy_descriptors(hs); + if (!f->hs_descriptors) + goto err; + } + if (ss) { + f->ss_descriptors = usb_copy_descriptors(ss); + if (!f->ss_descriptors) + goto err; + } + if (ssp) { + f->ssp_descriptors = usb_copy_descriptors(ssp); + if (!f->ssp_descriptors) + goto err; + } + return 0; +err: + usb_free_all_descriptors(f); + return -ENOMEM; +} +EXPORT_SYMBOL_GPL(usb_assign_descriptors); + +void usb_free_all_descriptors(struct usb_function *f) +{ + usb_free_descriptors(f->fs_descriptors); + f->fs_descriptors = NULL; + usb_free_descriptors(f->hs_descriptors); + f->hs_descriptors = NULL; + usb_free_descriptors(f->ss_descriptors); + f->ss_descriptors = NULL; + usb_free_descriptors(f->ssp_descriptors); + f->ssp_descriptors = NULL; +} +EXPORT_SYMBOL_GPL(usb_free_all_descriptors); + +struct usb_descriptor_header *usb_otg_descriptor_alloc( + struct usb_gadget *gadget) +{ + struct usb_descriptor_header *otg_desc; + unsigned length = 0; + + if (gadget->otg_caps && (gadget->otg_caps->otg_rev >= 0x0200)) + length = sizeof(struct usb_otg20_descriptor); + else + length = sizeof(struct usb_otg_descriptor); + + otg_desc = kzalloc(length, GFP_KERNEL); + return otg_desc; +} +EXPORT_SYMBOL_GPL(usb_otg_descriptor_alloc); + +int usb_otg_descriptor_init(struct usb_gadget *gadget, + struct usb_descriptor_header *otg_desc) +{ + struct usb_otg_descriptor *otg1x_desc; + struct usb_otg20_descriptor *otg20_desc; + struct usb_otg_caps *otg_caps = gadget->otg_caps; + u8 otg_attributes = 0; + + if (!otg_desc) + return -EINVAL; + + if (otg_caps && otg_caps->otg_rev) { + if (otg_caps->hnp_support) + otg_attributes |= USB_OTG_HNP; + if (otg_caps->srp_support) + otg_attributes |= USB_OTG_SRP; + if (otg_caps->adp_support && (otg_caps->otg_rev >= 0x0200)) + otg_attributes |= USB_OTG_ADP; + } else { + otg_attributes = USB_OTG_SRP | USB_OTG_HNP; + } + + if (otg_caps && (otg_caps->otg_rev >= 0x0200)) { + otg20_desc = (struct usb_otg20_descriptor *)otg_desc; + otg20_desc->bLength = sizeof(struct usb_otg20_descriptor); + otg20_desc->bDescriptorType = USB_DT_OTG; + otg20_desc->bmAttributes = otg_attributes; + otg20_desc->bcdOTG = cpu_to_le16(otg_caps->otg_rev); + } else { + otg1x_desc = (struct usb_otg_descriptor *)otg_desc; + otg1x_desc->bLength = sizeof(struct usb_otg_descriptor); + otg1x_desc->bDescriptorType = USB_DT_OTG; + otg1x_desc->bmAttributes = otg_attributes; + } + + return 0; +} +EXPORT_SYMBOL_GPL(usb_otg_descriptor_init); |