Whitebox
/
u-boot
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

dm: usb: Move descriptor setup code into its own function

Browse Source 
usb_new_device() is far too long and does far too much. As a first step, move
the code that does initial setup and reads a descriptor into its own function
called usb_setup_descriptor().

For XHCI the init order is different - we set up the device but don't
actually read the descriptor until after we set an address. Support this
option as a parameter to usb_setup_descriptor().

Avoid changing this torturous code more than necessary to make it easy to
review.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Marek Vasut <marex@denx.de>
master
Simon Glass 9 years ago
parent 862e75c0db
commit 128fcac087
1 changed files with 82 additions and 65 deletions
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Show Stats Download Patch File Download Diff File
  1. 147
      common/usb.c

147
common/usb.c
Unescape View File

@ -897,35 +897,12 @@ int usb_legacy_port_reset(struct usb_device *hub, int portnr)
return 0;
}
/*
* By the time we get here, the device has gotten a new device ID
* and is in the default state. We need to identify the thing and
* get the ball rolling..
*
* Returns 0 for success, != 0 for error.
*/
int usb_new_device(struct usb_device *dev)
static int usb_setup_descriptor(struct usb_device *dev, bool do_read)
{
int addr, err;
int tmp;
__maybe_unused struct usb_device_descriptor *desc;
ALLOC_CACHE_ALIGN_BUFFER(unsigned char, tmpbuf, USB_BUFSIZ);
/*
* Allocate usb 3.0 device context.
* USB 3.0 (xHCI) protocol tries to allocate device slot
* and related data structures first. This call does that.
* Refer to sec 4.3.2 in xHCI spec rev1.0
*/
if (usb_alloc_device(dev)) {
printf("Cannot allocate device context to get SLOT_ID\n");
return -EINVAL;
}
/* We still haven't set the Address yet */
addr = dev->devnum;
dev->devnum = 0;
/*
* This is a Windows scheme of initialization sequence, with double
* reset of the device (Linux uses the same sequence)
* Some equipment is said to work only with such init sequence; this
@ -940,55 +917,46 @@ int usb_new_device(struct usb_device *dev)
* the maxpacket size is 8 or 16 the device may be waiting to transmit
* some more, or keeps on retransmitting the 8 byte header. */
desc = (struct usb_device_descriptor *)tmpbuf;
dev->descriptor.bMaxPacketSize0 = 64; /* Start off at 64 bytes */
/* Default to 64 byte max packet size */
dev->maxpacketsize = PACKET_SIZE_64;
dev->epmaxpacketin[0] = 64;
dev->epmaxpacketout[0] = 64;
/*
* XHCI needs to issue a Address device command to setup
* proper device context structures, before it can interact
* with the device. So a get_descriptor will fail before any
* of that is done for XHCI unlike EHCI.
*/
#ifndef CONFIG_USB_XHCI
struct usb_device_descriptor *desc;
if (do_read) {
int err;
desc = (struct usb_device_descriptor *)tmpbuf;
err = usb_get_descriptor(dev, USB_DT_DEVICE, 0, desc, 64);
/*
* Validate we've received only at least 8 bytes, not that we've
* received the entire descriptor. The reasoning is:
* - The code only uses fields in the first 8 bytes, so that's all we
* need to have fetched at this stage.
* - The smallest maxpacket size is 8 bytes. Before we know the actual
* maxpacket the device uses, the USB controller may only accept a
* single packet. Consequently we are only guaranteed to receive 1
* packet (at least 8 bytes) even in a non-error case.
*
* At least the DWC2 controller needs to be programmed with the number
* of packets in addition to the number of bytes. A request for 64
* bytes of data with the maxpacket guessed as 64 (above) yields a
* request for 1 packet.
*/
if (err < 8) {
debug("usb_new_device: usb_get_descriptor() failed\n");
return -EIO;
err = usb_get_descriptor(dev, USB_DT_DEVICE, 0, desc, 64);
/*
* Validate we've received only at least 8 bytes, not that we've
* received the entire descriptor. The reasoning is:
* - The code only uses fields in the first 8 bytes, so that's all we
* need to have fetched at this stage.
* - The smallest maxpacket size is 8 bytes. Before we know the actual
* maxpacket the device uses, the USB controller may only accept a
* single packet. Consequently we are only guaranteed to receive 1
* packet (at least 8 bytes) even in a non-error case.
*
* At least the DWC2 controller needs to be programmed with the number
* of packets in addition to the number of bytes. A request for 64
* bytes of data with the maxpacket guessed as 64 (above) yields a
* request for 1 packet.
*/
if (err < 8) {
if (err < 0) {
printf("unable to get device descriptor (error=%d)\n",
err);
return err;
} else {
printf("USB device descriptor short read (expected %i, got %i)\n",
(int)sizeof(dev->descriptor), err);
return -EIO;
}
}
memcpy(&dev->descriptor, tmpbuf, sizeof(dev->descriptor));
}
dev->descriptor.bMaxPacketSize0 = desc->bMaxPacketSize0;
/*
* Fetch the device class, driver can use this info
* to differentiate between HUB and DEVICE.
*/
dev->descriptor.bDeviceClass = desc->bDeviceClass;
#endif
err = usb_legacy_port_reset(dev->parent, dev->portnr);
if (err)
return err;
dev->epmaxpacketin[0] = dev->descriptor.bMaxPacketSize0;
dev->epmaxpacketout[0] = dev->descriptor.bMaxPacketSize0;
switch (dev->descriptor.bMaxPacketSize0) {
@ -1008,6 +976,55 @@ int usb_new_device(struct usb_device *dev)
printf("usb_new_device: invalid max packet size\n");
return -EIO;
}
return 0;
}
/*
* By the time we get here, the device has gotten a new device ID
* and is in the default state. We need to identify the thing and
* get the ball rolling..
*
* Returns 0 for success, != 0 for error.
*/
int usb_new_device(struct usb_device *dev)
{
bool do_read = true;
int addr, err;
int tmp;
ALLOC_CACHE_ALIGN_BUFFER(unsigned char, tmpbuf, USB_BUFSIZ);
/*
* Allocate usb 3.0 device context.
* USB 3.0 (xHCI) protocol tries to allocate device slot
* and related data structures first. This call does that.
* Refer to sec 4.3.2 in xHCI spec rev1.0
*/
if (usb_alloc_device(dev)) {
printf("Cannot allocate device context to get SLOT_ID\n");
return -1;
}
/* We still haven't set the Address yet */
addr = dev->devnum;
dev->devnum = 0;
/*
* XHCI needs to issue a Address device command to setup
* proper device context structures, before it can interact
* with the device. So a get_descriptor will fail before any
* of that is done for XHCI unlike EHCI.
*/
#ifdef CONFIG_USB_XHCI
do_read = false;
#endif
err = usb_setup_descriptor(dev, do_read);
if (err)
return err;
err = usb_legacy_port_reset(dev->parent, dev->portnr);
if (err)
return err;
dev->devnum = addr;
err = usb_set_address(dev); /* set address */

Write Preview
Loading…
Cancel
Save