[RFC PATCH 3/5] usb: gadget: re-import epautoconf.c from kernel v6.16-rc7
Jerome Forissier
jerome.forissier at linaro.org
Fri Nov 21 16:37:52 CET 2025
Replace drivers/usb/gadget/epautoconf.c with the one from the Linux
kernel. Fixes will come later.
Signed-off-by: Jerome Forissier <jerome.forissier at linaro.org>
---
drivers/usb/gadget/epautoconf.c | 291 +++++++++++++++-----------------
1 file changed, 132 insertions(+), 159 deletions(-)
diff --git a/drivers/usb/gadget/epautoconf.c b/drivers/usb/gadget/epautoconf.c
index 495460473e9a..30016b805bfd 100644
--- a/drivers/usb/gadget/epautoconf.c
+++ b/drivers/usb/gadget/epautoconf.c
@@ -3,170 +3,120 @@
* epautoconf.c -- endpoint autoconfiguration for usb gadget drivers
*
* Copyright (C) 2004 David Brownell
- *
- * Ported to U-Boot by: Thomas Smits <ts.smits at gmail.com> and
- * Remy Bohmer <linux at bohmer.net>
*/
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/device.h>
+
+#include <linux/ctype.h>
+#include <linux/string.h>
+
#include <linux/usb/ch9.h>
-#include <linux/errno.h>
#include <linux/usb/gadget.h>
-#include <asm/unaligned.h>
-#define isdigit(c) ('0' <= (c) && (c) <= '9')
-
-/* we must assign addresses for configurable endpoints (like net2280) */
-static unsigned epnum;
-
-/* #define MANY_ENDPOINTS */
-#ifdef MANY_ENDPOINTS
-/* more than 15 configurable endpoints */
-static unsigned in_epnum;
-#endif
-
-/*
- * This should work with endpoints from controller drivers sharing the
- * same endpoint naming convention. By example:
+/**
+ * usb_ep_autoconfig_ss() - choose an endpoint matching the ep
+ * descriptor and ep companion descriptor
+ * @gadget: The device to which the endpoint must belong.
+ * @desc: Endpoint descriptor, with endpoint direction and transfer mode
+ * initialized. For periodic transfers, the maximum packet
+ * size must also be initialized. This is modified on
+ * success.
+ * @ep_comp: Endpoint companion descriptor, with the required
+ * number of streams. Will be modified when the chosen EP
+ * supports a different number of streams.
+ *
+ * This routine replaces the usb_ep_autoconfig when needed
+ * superspeed enhancments. If such enhancemnets are required,
+ * the FD should call usb_ep_autoconfig_ss directly and provide
+ * the additional ep_comp parameter.
+ *
+ * By choosing an endpoint to use with the specified descriptor,
+ * this routine simplifies writing gadget drivers that work with
+ * multiple USB device controllers. The endpoint would be
+ * passed later to usb_ep_enable(), along with some descriptor.
+ *
+ * That second descriptor won't always be the same as the first one.
+ * For example, isochronous endpoints can be autoconfigured for high
+ * bandwidth, and then used in several lower bandwidth altsettings.
+ * Also, high and full speed descriptors will be different.
*
- * - ep1, ep2, ... address is fixed, not direction or type
- * - ep1in, ep2out, ... address and direction are fixed, not type
- * - ep1-bulk, ep2-bulk, ... address and type are fixed, not direction
- * - ep1in-bulk, ep2out-iso, ... all three are fixed
- * - ep-* ... no functionality restrictions
+ * Be sure to examine and test the results of autoconfiguration
+ * on your hardware. This code may not make the best choices
+ * about how to use the USB controller, and it can't know all
+ * the restrictions that may apply. Some combinations of driver
+ * and hardware won't be able to autoconfigure.
*
- * Type suffixes are "-bulk", "-iso", or "-int". Numbers are decimal.
- * Less common restrictions are implied by gadget_is_*().
+ * On success, this returns an claimed usb_ep, and modifies the endpoint
+ * descriptor bEndpointAddress. For bulk endpoints, the wMaxPacket value
+ * is initialized as if the endpoint were used at full speed and
+ * the bmAttribute field in the ep companion descriptor is
+ * updated with the assigned number of streams if it is
+ * different from the original value. To prevent the endpoint
+ * from being returned by a later autoconfig call, claims it by
+ * assigning ep->claimed to true.
*
- * NOTE: each endpoint is unidirectional, as specified by its USB
- * descriptor; and isn't specific to a configuration or altsetting.
+ * On failure, this returns a null endpoint descriptor.
*/
-static int ep_matches(
+struct usb_ep *usb_ep_autoconfig_ss(
struct usb_gadget *gadget,
- struct usb_ep *ep,
- struct usb_endpoint_descriptor *desc
+ struct usb_endpoint_descriptor *desc,
+ struct usb_ss_ep_comp_descriptor *ep_comp
)
{
- u8 type;
- const char *tmp;
- u16 max;
+ struct usb_ep *ep;
- /* endpoint already claimed? */
- if (NULL != ep->driver_data)
- return 0;
-
- /* only support ep0 for portable CONTROL traffic */
- type = desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK;
- if (USB_ENDPOINT_XFER_CONTROL == type)
- return 0;
-
- /* some other naming convention */
- if ('e' != ep->name[0])
- return 0;
-
- /* type-restriction: "-iso", "-bulk", or "-int".
- * direction-restriction: "in", "out".
- */
- if ('-' != ep->name[2]) {
- tmp = strrchr(ep->name, '-');
- if (tmp) {
- switch (type) {
- case USB_ENDPOINT_XFER_INT:
- /* bulk endpoints handle interrupt transfers,
- * except the toggle-quirky iso-synch kind
- */
- if ('s' == tmp[2]) /* == "-iso" */
- return 0;
- break;
- case USB_ENDPOINT_XFER_BULK:
- if ('b' != tmp[1]) /* != "-bulk" */
- return 0;
- break;
- case USB_ENDPOINT_XFER_ISOC:
- if ('s' != tmp[2]) /* != "-iso" */
- return 0;
- }
- } else {
- tmp = ep->name + strlen(ep->name);
- }
-
- /* direction-restriction: "..in-..", "out-.." */
- tmp--;
- if (!isdigit(*tmp)) {
- if (desc->bEndpointAddress & USB_DIR_IN) {
- if ('n' != *tmp)
- return 0;
- } else {
- if ('t' != *tmp)
- return 0;
- }
- }
+ if (gadget->ops->match_ep) {
+ ep = gadget->ops->match_ep(gadget, desc, ep_comp);
+ if (ep)
+ goto found_ep;
}
- /* endpoint maxpacket size is an input parameter, except for bulk
- * where it's an output parameter representing the full speed limit.
- * the usb spec fixes high speed bulk maxpacket at 512 bytes.
- */
- max = 0x7ff & le16_to_cpu(get_unaligned(&desc->wMaxPacketSize));
- switch (type) {
- case USB_ENDPOINT_XFER_INT:
- /* INT: limit 64 bytes full speed, 1024 high speed */
- if (!gadget->is_dualspeed && max > 64)
- return 0;
- /* FALLTHROUGH */
-
- case USB_ENDPOINT_XFER_ISOC:
- /* ISO: limit 1023 bytes full speed, 1024 high speed */
- if (ep->maxpacket < max)
- return 0;
- if (!gadget->is_dualspeed && max > 1023)
- return 0;
-
- /* BOTH: "high bandwidth" works only at high speed */
- if ((get_unaligned(&desc->wMaxPacketSize) &
- __constant_cpu_to_le16(3<<11))) {
- if (!gadget->is_dualspeed)
- return 0;
- /* configure your hardware with enough buffering!! */
- }
- break;
+ /* Second, look at endpoints until an unclaimed one looks usable */
+ list_for_each_entry (ep, &gadget->ep_list, ep_list) {
+ if (usb_gadget_ep_match_desc(gadget, ep, desc, ep_comp))
+ goto found_ep;
}
- /* MATCH!! */
+ /* Fail */
+ return NULL;
+found_ep:
+
+ /*
+ * If the protocol driver hasn't yet decided on wMaxPacketSize
+ * and wants to know the maximum possible, provide the info.
+ */
+ if (desc->wMaxPacketSize == 0)
+ desc->wMaxPacketSize = cpu_to_le16(ep->maxpacket_limit);
/* report address */
+ desc->bEndpointAddress &= USB_DIR_IN;
if (isdigit(ep->name[2])) {
- u8 num = dectoul(&ep->name[2], NULL);
+ u8 num = simple_strtoul(&ep->name[2], NULL, 10);
desc->bEndpointAddress |= num;
-#ifdef MANY_ENDPOINTS
} else if (desc->bEndpointAddress & USB_DIR_IN) {
- if (++in_epnum > 15)
- return 0;
- desc->bEndpointAddress = USB_DIR_IN | in_epnum;
-#endif
+ if (++gadget->in_epnum > 15)
+ return NULL;
+ desc->bEndpointAddress = USB_DIR_IN | gadget->in_epnum;
} else {
- if (++epnum > 15)
- return 0;
- desc->bEndpointAddress |= epnum;
+ if (++gadget->out_epnum > 15)
+ return NULL;
+ desc->bEndpointAddress |= gadget->out_epnum;
}
- /* report (variable) full speed bulk maxpacket */
- if (USB_ENDPOINT_XFER_BULK == type) {
- int size = ep->maxpacket;
-
- /* min() doesn't work on bitfields with gcc-3.5 */
- if (size > 64)
- size = 64;
- put_unaligned(cpu_to_le16(size), &desc->wMaxPacketSize);
- }
-
- if (gadget->ops->ep_conf)
- return gadget->ops->ep_conf(gadget, ep, desc);
-
- return 1;
+ ep->address = desc->bEndpointAddress;
+ ep->desc = NULL;
+ ep->comp_desc = NULL;
+ ep->claimed = true;
+ return ep;
}
+EXPORT_SYMBOL_GPL(usb_ep_autoconfig_ss);
/**
- * usb_ep_autoconfig - choose an endpoint matching the descriptor
+ * usb_ep_autoconfig() - choose an endpoint matching the
+ * descriptor
* @gadget: The device to which the endpoint must belong.
* @desc: Endpoint descriptor, with endpoint direction and transfer mode
* initialized. For periodic transfers, the maximum packet
@@ -187,11 +137,12 @@ static int ep_matches(
* USB controller, and it can't know all the restrictions that may apply.
* Some combinations of driver and hardware won't be able to autoconfigure.
*
- * On success, this returns an un-claimed usb_ep, and modifies the endpoint
+ * On success, this returns an claimed usb_ep, and modifies the endpoint
* descriptor bEndpointAddress. For bulk endpoints, the wMaxPacket value
- * is initialized as if the endpoint were used at full speed. To prevent
- * the endpoint from being returned by a later autoconfig call, claim it
- * by assigning ep->driver_data to some non-null value.
+ * is initialized as if the endpoint were used at full speed. Because of
+ * that the users must consider adjusting the autoconfigured descriptor.
+ * To prevent the endpoint from being returned by a later autoconfig call,
+ * claims it by assigning ep->claimed to true.
*
* On failure, this returns a null endpoint descriptor.
*/
@@ -200,23 +151,45 @@ struct usb_ep *usb_ep_autoconfig(
struct usb_endpoint_descriptor *desc
)
{
- struct usb_ep *ep;
+ struct usb_ep *ep;
+ u8 type;
- if (gadget->ops->match_ep) {
- ep = gadget->ops->match_ep(gadget, desc, NULL);
- if (ep && ep_matches(gadget, ep, desc))
- return ep;
- }
+ ep = usb_ep_autoconfig_ss(gadget, desc, NULL);
+ if (!ep)
+ return NULL;
+
+ type = usb_endpoint_type(desc);
+
+ /* report (variable) full speed bulk maxpacket */
+ if (type == USB_ENDPOINT_XFER_BULK) {
+ int size = ep->maxpacket_limit;
- /* Second, look at endpoints until an unclaimed one looks usable */
- list_for_each_entry(ep, &gadget->ep_list, ep_list) {
- if (ep_matches(gadget, ep, desc))
- return ep;
+ /* min() doesn't work on bitfields with gcc-3.5 */
+ if (size > 64)
+ size = 64;
+ desc->wMaxPacketSize = cpu_to_le16(size);
}
- /* Fail */
- return NULL;
+ return ep;
+}
+EXPORT_SYMBOL_GPL(usb_ep_autoconfig);
+
+/**
+ * usb_ep_autoconfig_release - releases endpoint and set it to initial state
+ * @ep: endpoint which should be released
+ *
+ * This function can be used during function bind for endpoints obtained
+ * from usb_ep_autoconfig(). It unclaims endpoint claimed by
+ * usb_ep_autoconfig() to make it available for other functions. Endpoint
+ * which was released is no longer valid and shouldn't be used in
+ * context of function which released it.
+ */
+void usb_ep_autoconfig_release(struct usb_ep *ep)
+{
+ ep->claimed = false;
+ ep->driver_data = NULL;
}
+EXPORT_SYMBOL_GPL(usb_ep_autoconfig_release);
/**
* usb_ep_autoconfig_reset - reset endpoint autoconfig state
@@ -224,18 +197,18 @@ struct usb_ep *usb_ep_autoconfig(
*
* Use this for devices where one configuration may need to assign
* endpoint resources very differently from the next one. It clears
- * state such as ep->driver_data and the record of assigned endpoints
+ * state such as ep->claimed and the record of assigned endpoints
* used by usb_ep_autoconfig().
*/
-void usb_ep_autoconfig_reset(struct usb_gadget *gadget)
+void usb_ep_autoconfig_reset (struct usb_gadget *gadget)
{
struct usb_ep *ep;
- list_for_each_entry(ep, &gadget->ep_list, ep_list) {
+ list_for_each_entry (ep, &gadget->ep_list, ep_list) {
+ ep->claimed = false;
ep->driver_data = NULL;
}
-#ifdef MANY_ENDPOINTS
- in_epnum = 0;
-#endif
- epnum = 0;
+ gadget->in_epnum = 0;
+ gadget->out_epnum = 0;
}
+EXPORT_SYMBOL_GPL(usb_ep_autoconfig_reset);
--
2.48.1
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