Re: [PATCH] USB and Driver Core patches for 2.6.10

Greg KH
2005-01-08T08:38:43Z

ChangeSet 1.1938.446.13, 2004/12/15 16:31:49-08:00, david-b@pacbell.net

[PATCH] USB: usb_dev->ep[] not usb_dev->epmaxpacket (1/15)

This starts updating the usbcore interface to use endpoints in places it
previously used pipes or other representations of the endpoint.

- add new arrays of "struct usb_host_endpoint" pointers, matching
current config and altsetting

- get rid of the two epmaxpacket[] arrays; they duplicate information
that's now readily accessible from the usb_host_endpoint.

- resolve a FIXME by removing a function that only existed because
the usb_host_endpoint wasn't readily accessible.

It also removes most of an old rant about pipes, trimming it down so
only the important bits remain.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

include/linux/usb.h | 73 ++++++++++++++++++++++++++--------------------------
1 files changed, 37 insertions(+), 36 deletions(-)

diff -Nru a/include/linux/usb.h b/include/linux/usb.h
--- a/include/linux/usb.h 2005-01-07 15:49:52 -08:00
+++ b/include/linux/usb.h 2005-01-07 15:49:52 -08:00
@@ -224,11 +224,6 @@
int extralen;
};

-// FIXME remove; exported only for drivers/usb/misc/auserwald.c
-// prefer usb_device->epnum[0..31]
-extern struct usb_endpoint_descriptor *
- usb_epnum_to_ep_desc(struct usb_device *dev, unsigned epnum);
-
int __usb_get_extra_descriptor(char *buffer, unsigned size,
unsigned char type, void **ptr);
#define usb_get_extra_descriptor(ifpoint,type,ptr)\
@@ -311,17 +306,19 @@
struct semaphore serialize;

unsigned int toggle[2]; /* one bit for each endpoint ([0] = IN, [1] = OUT) */
- int epmaxpacketin[16]; /* INput endpoint specific maximums */
- int epmaxpacketout[16]; /* OUTput endpoint specific maximums */

struct usb_device *parent; /* our hub, unless we're the root */
struct usb_bus *bus; /* Bus we're part of */
+ struct usb_host_endpoint ep0;

struct device dev; /* Generic device interface */

struct usb_device_descriptor descriptor;/* Descriptor */
struct usb_host_config *config; /* All of the configs */
+
struct usb_host_config *actconfig;/* the active configuration */
+ struct usb_host_endpoint *ep_in[16];
+ struct usb_host_endpoint *ep_out[16];

char **rawdescriptors; /* Raw descriptors for each config */

@@ -360,6 +357,8 @@

extern struct usb_device *usb_find_device(u16 vendor_id, u16 product_id);

+/*-------------------------------------------------------------------------*/
+
/* for drivers using iso endpoints */
extern int usb_get_current_frame_number (struct usb_device *usb_dev);

@@ -1040,55 +1039,35 @@
/* -------------------------------------------------------------------------- */

/*
- * Calling this entity a "pipe" is glorifying it. A USB pipe
- * is something embarrassingly simple: it basically consists
- * of the following information:
- * - device number (7 bits)
- * - endpoint number (4 bits)
- * - current Data0/1 state (1 bit) [Historical; now gone]
- * - direction (1 bit)
- * - speed (1 bit) [Historical and specific to USB 1.1; now gone.]
- * - max packet size (2 bits: 8, 16, 32 or 64) [Historical; now gone.]
- * - pipe type (2 bits: control, interrupt, bulk, isochronous)
- *
- * That's 18 bits. Really. Nothing more. And the USB people have
- * documented these eighteen bits as some kind of glorious
- * virtual data structure.
+ * For various legacy reasons, Linux has a small cookie that's paired with
+ * a struct usb_device to identify an endpoint queue. Queue characteristics
+ * are defined by the endpoint's descriptor. This cookie is called a "pipe",
+ * an unsigned int encoded as:
*
- * Let's not fall in that trap. We'll just encode it as a simple
- * unsigned int. The encoding is:
- *
- * - max size: bits 0-1 [Historical; now gone.]
* - direction: bit 7 (0 = Host-to-Device [Out],
* 1 = Device-to-Host [In] ...
* like endpoint bEndpointAddress)
- * - device: bits 8-14 ... bit positions known to uhci-hcd
+ * - device address: bits 8-14 ... bit positions known to uhci-hcd
* - endpoint: bits 15-18 ... bit positions known to uhci-hcd
- * - Data0/1: bit 19 [Historical; now gone. ]
- * - lowspeed: bit 26 [Historical; now gone. ]
* - pipe type: bits 30-31 (00 = isochronous, 01 = interrupt,
* 10 = control, 11 = bulk)
*
- * Why? Because it's arbitrary, and whatever encoding we select is really
- * up to us. This one happens to share a lot of bit positions with the UHCI
- * specification, so that much of the uhci driver can just mask the bits
- * appropriately.
+ * Given the device address and endpoint descriptor, pipes are redundant.
*/

/* NOTE: these are not the standard USB_ENDPOINT_XFER_* values!! */
+/* (yet ... they're the values used by usbfs) */
#define PIPE_ISOCHRONOUS 0
#define PIPE_INTERRUPT 1
#define PIPE_CONTROL 2
#define PIPE_BULK 3

-#define usb_maxpacket(dev, pipe, out) (out \
- ? (dev)->epmaxpacketout[usb_pipeendpoint(pipe)] \
- : (dev)->epmaxpacketin [usb_pipeendpoint(pipe)] )
-
#define usb_pipein(pipe) ((pipe) & USB_DIR_IN)
#define usb_pipeout(pipe) (!usb_pipein(pipe))
+
#define usb_pipedevice(pipe) (((pipe) >> 8) & 0x7f)
#define usb_pipeendpoint(pipe) (((pipe) >> 15) & 0xf)
+
#define usb_pipetype(pipe) (((pipe) >> 30) & 3)
#define usb_pipeisoc(pipe) (usb_pipetype((pipe)) == PIPE_ISOCHRONOUS)
#define usb_pipeint(pipe) (usb_pipetype((pipe)) == PIPE_INTERRUPT)
@@ -1115,6 +1094,28 @@
#define usb_rcvbulkpipe(dev,endpoint) ((PIPE_BULK << 30) | __create_pipe(dev,endpoint) | USB_DIR_IN)
#define usb_sndintpipe(dev,endpoint) ((PIPE_INTERRUPT << 30) | __create_pipe(dev,endpoint))
#define usb_rcvintpipe(dev,endpoint) ((PIPE_INTERRUPT << 30) | __create_pipe(dev,endpoint) | USB_DIR_IN)
+
+/*-------------------------------------------------------------------------*/
+
+static inline __u16
+usb_maxpacket(struct usb_device *udev, int pipe, int is_out)
+{
+ struct usb_host_endpoint *ep;
+ unsigned epnum = usb_pipeendpoint(pipe);
+
+ if (is_out) {
+ WARN_ON(usb_pipein(pipe));
+ ep = udev->ep_out[epnum];
+ } else {
+ WARN_ON(usb_pipeout(pipe));
+ ep = udev->ep_in[epnum];
+ }
+ if (!ep)
+ return 0;
+
+ /* NOTE: only 0x07ff bits are for packet size... */
+ return ep->desc.wMaxPacketSize;
+}

/* -------------------------------------------------------------------------- */