dm: usb: Move descriptor setup code into its own function
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>
This commit is contained in:
Simon Glass
parent
862e75c0db
commit
128fcac087
147
common/usb.c
147
common/usb.c
@ -897,34 +897,11 @@ int usb_legacy_port_reset(struct usb_device *hub, int portnr)
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return 0;
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}
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/*
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* By the time we get here, the device has gotten a new device ID
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* and is in the default state. We need to identify the thing and
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* get the ball rolling..
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*
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* Returns 0 for success, != 0 for error.
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*/
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int usb_new_device(struct usb_device *dev)
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static int usb_setup_descriptor(struct usb_device *dev, bool do_read)
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{
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int addr, err;
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int tmp;
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__maybe_unused struct usb_device_descriptor *desc;
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ALLOC_CACHE_ALIGN_BUFFER(unsigned char, tmpbuf, USB_BUFSIZ);
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/*
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* Allocate usb 3.0 device context.
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* USB 3.0 (xHCI) protocol tries to allocate device slot
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* and related data structures first. This call does that.
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* Refer to sec 4.3.2 in xHCI spec rev1.0
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*/
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if (usb_alloc_device(dev)) {
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printf("Cannot allocate device context to get SLOT_ID\n");
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return -EINVAL;
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}
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/* We still haven't set the Address yet */
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addr = dev->devnum;
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dev->devnum = 0;
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/*
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* This is a Windows scheme of initialization sequence, with double
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* reset of the device (Linux uses the same sequence)
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@ -940,55 +917,46 @@ int usb_new_device(struct usb_device *dev)
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* the maxpacket size is 8 or 16 the device may be waiting to transmit
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* some more, or keeps on retransmitting the 8 byte header. */
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desc = (struct usb_device_descriptor *)tmpbuf;
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dev->descriptor.bMaxPacketSize0 = 64; /* Start off at 64 bytes */
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/* Default to 64 byte max packet size */
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dev->maxpacketsize = PACKET_SIZE_64;
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dev->epmaxpacketin[0] = 64;
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dev->epmaxpacketout[0] = 64;
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/*
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* XHCI needs to issue a Address device command to setup
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* proper device context structures, before it can interact
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* with the device. So a get_descriptor will fail before any
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* of that is done for XHCI unlike EHCI.
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*/
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#ifndef CONFIG_USB_XHCI
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struct usb_device_descriptor *desc;
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if (do_read) {
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int err;
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desc = (struct usb_device_descriptor *)tmpbuf;
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err = usb_get_descriptor(dev, USB_DT_DEVICE, 0, desc, 64);
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/*
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* Validate we've received only at least 8 bytes, not that we've
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* received the entire descriptor. The reasoning is:
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* - The code only uses fields in the first 8 bytes, so that's all we
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* need to have fetched at this stage.
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* - The smallest maxpacket size is 8 bytes. Before we know the actual
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* maxpacket the device uses, the USB controller may only accept a
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* single packet. Consequently we are only guaranteed to receive 1
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* packet (at least 8 bytes) even in a non-error case.
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*
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* At least the DWC2 controller needs to be programmed with the number
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* of packets in addition to the number of bytes. A request for 64
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* bytes of data with the maxpacket guessed as 64 (above) yields a
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* request for 1 packet.
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*/
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if (err < 8) {
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debug("usb_new_device: usb_get_descriptor() failed\n");
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return -EIO;
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err = usb_get_descriptor(dev, USB_DT_DEVICE, 0, desc, 64);
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/*
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* Validate we've received only at least 8 bytes, not that we've
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* received the entire descriptor. The reasoning is:
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* - The code only uses fields in the first 8 bytes, so that's all we
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* need to have fetched at this stage.
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* - The smallest maxpacket size is 8 bytes. Before we know the actual
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* maxpacket the device uses, the USB controller may only accept a
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* single packet. Consequently we are only guaranteed to receive 1
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* packet (at least 8 bytes) even in a non-error case.
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*
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* At least the DWC2 controller needs to be programmed with the number
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* of packets in addition to the number of bytes. A request for 64
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* bytes of data with the maxpacket guessed as 64 (above) yields a
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* request for 1 packet.
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*/
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if (err < 8) {
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if (err < 0) {
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printf("unable to get device descriptor (error=%d)\n",
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err);
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return err;
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} else {
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printf("USB device descriptor short read (expected %i, got %i)\n",
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(int)sizeof(dev->descriptor), err);
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return -EIO;
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}
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}
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memcpy(&dev->descriptor, tmpbuf, sizeof(dev->descriptor));
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}
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dev->descriptor.bMaxPacketSize0 = desc->bMaxPacketSize0;
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/*
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* Fetch the device class, driver can use this info
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* to differentiate between HUB and DEVICE.
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*/
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dev->descriptor.bDeviceClass = desc->bDeviceClass;
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#endif
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err = usb_legacy_port_reset(dev->parent, dev->portnr);
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if (err)
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return err;
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dev->epmaxpacketin[0] = dev->descriptor.bMaxPacketSize0;
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dev->epmaxpacketout[0] = dev->descriptor.bMaxPacketSize0;
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switch (dev->descriptor.bMaxPacketSize0) {
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@ -1008,6 +976,55 @@ int usb_new_device(struct usb_device *dev)
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printf("usb_new_device: invalid max packet size\n");
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return -EIO;
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}
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return 0;
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}
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/*
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* By the time we get here, the device has gotten a new device ID
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* and is in the default state. We need to identify the thing and
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* get the ball rolling..
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*
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* Returns 0 for success, != 0 for error.
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*/
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int usb_new_device(struct usb_device *dev)
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{
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bool do_read = true;
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int addr, err;
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int tmp;
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ALLOC_CACHE_ALIGN_BUFFER(unsigned char, tmpbuf, USB_BUFSIZ);
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/*
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* Allocate usb 3.0 device context.
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* USB 3.0 (xHCI) protocol tries to allocate device slot
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* and related data structures first. This call does that.
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* Refer to sec 4.3.2 in xHCI spec rev1.0
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*/
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if (usb_alloc_device(dev)) {
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printf("Cannot allocate device context to get SLOT_ID\n");
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return -1;
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}
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/* We still haven't set the Address yet */
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addr = dev->devnum;
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dev->devnum = 0;
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/*
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* XHCI needs to issue a Address device command to setup
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* proper device context structures, before it can interact
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* with the device. So a get_descriptor will fail before any
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* of that is done for XHCI unlike EHCI.
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*/
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#ifdef CONFIG_USB_XHCI
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do_read = false;
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#endif
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err = usb_setup_descriptor(dev, do_read);
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if (err)
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return err;
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err = usb_legacy_port_reset(dev->parent, dev->portnr);
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if (err)
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return err;
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dev->devnum = addr;
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err = usb_set_address(dev); /* set address */
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