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

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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 10 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
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  1. 147
      common/usb.c

147
common/usb.c
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@ -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 */

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