Add qemu 2.4.0
[kvmfornfv.git] / qemu / roms / u-boot / drivers / usb / gadget / mpc8xx_udc.c
diff --git a/qemu/roms/u-boot/drivers/usb/gadget/mpc8xx_udc.c b/qemu/roms/u-boot/drivers/usb/gadget/mpc8xx_udc.c
new file mode 100644 (file)
index 0000000..7f72972
--- /dev/null
@@ -0,0 +1,1386 @@
+/*
+ * Copyright (C) 2006 by Bryan O'Donoghue, CodeHermit
+ * bodonoghue@CodeHermit.ie
+ *
+ * References
+ * DasUBoot/drivers/usb/gadget/omap1510_udc.c, for design and implementation
+ * ideas.
+ *
+ * SPDX-License-Identifier:    GPL-2.0+
+ */
+
+/*
+ * Notes :
+ * 1.  #define __SIMULATE_ERROR__ to inject a CRC error into every 2nd TX
+ *             packet to force the USB re-transmit protocol.
+ *
+ * 2.  #define __DEBUG_UDC__ to switch on debug tracing to serial console
+ *     be careful that tracing doesn't create Hiesen-bugs with respect to
+ *     response timeouts to control requests.
+ *
+ * 3.  This driver should be able to support any higher level driver that
+ *     that wants to do either of the two standard UDC implementations
+ *     Control-Bulk-Interrupt or  Bulk-IN/Bulk-Out standards. Hence
+ *     gserial and cdc_acm should work with this code.
+ *
+ * 4.  NAK events never actually get raised at all, the documentation
+ *     is just wrong !
+ *
+ * 5.  For some reason, cbd_datlen is *always* +2 the value it should be.
+ *     this means that having an RX cbd of 16 bytes is not possible, since
+ *     the same size is reported for 14 bytes received as 16 bytes received
+ *     until we can find out why this happens, RX cbds must be limited to 8
+ *     bytes. TODO: check errata for this behaviour.
+ *
+ * 6.  Right now this code doesn't support properly powering up with the USB
+ *     cable attached to the USB host my development board the Adder87x doesn't
+ *     have a pull-up fitted to allow this, so it is necessary to power the
+ *     board and *then* attached the USB cable to the host. However somebody
+ *     with a different design in their board may be able to keep the cable
+ *     constantly connected and simply enable/disable a pull-up  re
+ *     figure 31.1 in MPC885RM.pdf instead of having to power up the board and
+ *     then attach the cable !
+ *
+ */
+#include <common.h>
+#include <config.h>
+#include <commproc.h>
+#include <usbdevice.h>
+#include <usb/mpc8xx_udc.h>
+#include <usb/udc.h>
+
+#include "ep0.h"
+
+DECLARE_GLOBAL_DATA_PTR;
+
+#define ERR(fmt, args...)\
+       serial_printf("ERROR : [%s] %s:%d: "fmt,\
+                               __FILE__,__FUNCTION__,__LINE__, ##args)
+#ifdef __DEBUG_UDC__
+#define DBG(fmt,args...)\
+               serial_printf("[%s] %s:%d: "fmt,\
+                               __FILE__,__FUNCTION__,__LINE__, ##args)
+#else
+#define DBG(fmt,args...)
+#endif
+
+/* Static Data */
+#ifdef __SIMULATE_ERROR__
+static char err_poison_test = 0;
+#endif
+static struct mpc8xx_ep ep_ref[MAX_ENDPOINTS];
+static u32 address_base = STATE_NOT_READY;
+static mpc8xx_udc_state_t udc_state = 0;
+static struct usb_device_instance *udc_device = 0;
+static volatile usb_epb_t *endpoints[MAX_ENDPOINTS];
+static volatile cbd_t *tx_cbd[TX_RING_SIZE];
+static volatile cbd_t *rx_cbd[RX_RING_SIZE];
+static volatile immap_t *immr = 0;
+static volatile cpm8xx_t *cp = 0;
+static volatile usb_pram_t *usb_paramp = 0;
+static volatile usb_t *usbp = 0;
+static int rx_ct = 0;
+static int tx_ct = 0;
+
+/* Static Function Declarations */
+static void mpc8xx_udc_state_transition_up (usb_device_state_t initial,
+                                           usb_device_state_t final);
+static void mpc8xx_udc_state_transition_down (usb_device_state_t initial,
+                                             usb_device_state_t final);
+static void mpc8xx_udc_stall (unsigned int ep);
+static void mpc8xx_udc_flush_tx_fifo (int epid);
+static void mpc8xx_udc_flush_rx_fifo (void);
+static void mpc8xx_udc_clear_rxbd (volatile cbd_t * rx_cbdp);
+static void mpc8xx_udc_init_tx (struct usb_endpoint_instance *epi,
+                               struct urb *tx_urb);
+static void mpc8xx_udc_dump_request (struct usb_device_request *request);
+static void mpc8xx_udc_clock_init (volatile immap_t * immr,
+                                  volatile cpm8xx_t * cp);
+static int mpc8xx_udc_ep_tx (struct usb_endpoint_instance *epi);
+static int mpc8xx_udc_epn_rx (unsigned int epid, volatile cbd_t * rx_cbdp);
+static void mpc8xx_udc_ep0_rx (volatile cbd_t * rx_cbdp);
+static void mpc8xx_udc_cbd_init (void);
+static void mpc8xx_udc_endpoint_init (void);
+static void mpc8xx_udc_cbd_attach (int ep, uchar tx_size, uchar rx_size);
+static u32 mpc8xx_udc_alloc (u32 data_size, u32 alignment);
+static int mpc8xx_udc_ep0_rx_setup (volatile cbd_t * rx_cbdp);
+static void mpc8xx_udc_set_nak (unsigned int ep);
+static short mpc8xx_udc_handle_txerr (void);
+static void mpc8xx_udc_advance_rx (volatile cbd_t ** rx_cbdp, int epid);
+
+/******************************************************************************
+                              Global Linkage
+ *****************************************************************************/
+
+/* udc_init
+ *
+ * Do initial bus gluing
+ */
+int udc_init (void)
+{
+       /* Init various pointers */
+       immr = (immap_t *) CONFIG_SYS_IMMR;
+       cp = (cpm8xx_t *) & (immr->im_cpm);
+       usb_paramp = (usb_pram_t *) & (cp->cp_dparam[PROFF_USB]);
+       usbp = (usb_t *) & (cp->cp_scc[0]);
+
+       memset (ep_ref, 0x00, (sizeof (struct mpc8xx_ep) * MAX_ENDPOINTS));
+
+       udc_device = 0;
+       udc_state = STATE_NOT_READY;
+
+       usbp->usmod = 0x00;
+       usbp->uscom = 0;
+
+       /* Set USB Frame #0, Respond at Address & Get a clock source  */
+       usbp->usaddr = 0x00;
+       mpc8xx_udc_clock_init (immr, cp);
+
+       /* PA15, PA14 as perhiperal USBRXD and USBOE */
+       immr->im_ioport.iop_padir &= ~0x0003;
+       immr->im_ioport.iop_papar |= 0x0003;
+
+       /* PC11/PC10 as peripheral USBRXP USBRXN */
+       immr->im_ioport.iop_pcso |= 0x0030;
+
+       /* PC7/PC6 as perhiperal USBTXP and USBTXN */
+       immr->im_ioport.iop_pcdir |= 0x0300;
+       immr->im_ioport.iop_pcpar |= 0x0300;
+
+       /* Set the base address */
+       address_base = (u32) (cp->cp_dpmem + CPM_USB_BASE);
+
+       /* Initialise endpoints and circular buffers */
+       mpc8xx_udc_endpoint_init ();
+       mpc8xx_udc_cbd_init ();
+
+       /* Assign allocated Dual Port Endpoint descriptors */
+       usb_paramp->ep0ptr = (u32) endpoints[0];
+       usb_paramp->ep1ptr = (u32) endpoints[1];
+       usb_paramp->ep2ptr = (u32) endpoints[2];
+       usb_paramp->ep3ptr = (u32) endpoints[3];
+       usb_paramp->frame_n = 0;
+
+       DBG ("ep0ptr=0x%08x ep1ptr=0x%08x ep2ptr=0x%08x ep3ptr=0x%08x\n",
+            usb_paramp->ep0ptr, usb_paramp->ep1ptr, usb_paramp->ep2ptr,
+            usb_paramp->ep3ptr);
+
+       return 0;
+}
+
+/* udc_irq
+ *
+ * Poll for whatever events may have occured
+ */
+void udc_irq (void)
+{
+       int epid = 0;
+       volatile cbd_t *rx_cbdp = 0;
+       volatile cbd_t *rx_cbdp_base = 0;
+
+       if (udc_state != STATE_READY) {
+               return;
+       }
+
+       if (usbp->usber & USB_E_BSY) {
+               /* This shouldn't happen. If it does then it's a bug ! */
+               usbp->usber |= USB_E_BSY;
+               mpc8xx_udc_flush_rx_fifo ();
+       }
+
+       /* Scan all RX/Bidirectional Endpoints for RX data. */
+       for (epid = 0; epid < MAX_ENDPOINTS; epid++) {
+               if (!ep_ref[epid].prx) {
+                       continue;
+               }
+               rx_cbdp = rx_cbdp_base = ep_ref[epid].prx;
+
+               do {
+                       if (!(rx_cbdp->cbd_sc & RX_BD_E)) {
+
+                               if (rx_cbdp->cbd_sc & 0x1F) {
+                                       /* Corrupt data discard it.
+                                        * Controller has NAK'd this packet.
+                                        */
+                                       mpc8xx_udc_clear_rxbd (rx_cbdp);
+
+                               } else {
+                                       if (!epid) {
+                                               mpc8xx_udc_ep0_rx (rx_cbdp);
+
+                                       } else {
+                                               /* Process data */
+                                               mpc8xx_udc_set_nak (epid);
+                                               mpc8xx_udc_epn_rx (epid, rx_cbdp);
+                                               mpc8xx_udc_clear_rxbd (rx_cbdp);
+                                       }
+                               }
+
+                               /* Advance RX CBD pointer */
+                               mpc8xx_udc_advance_rx (&rx_cbdp, epid);
+                               ep_ref[epid].prx = rx_cbdp;
+                       } else {
+                               /* Advance RX CBD pointer */
+                               mpc8xx_udc_advance_rx (&rx_cbdp, epid);
+                       }
+
+               } while (rx_cbdp != rx_cbdp_base);
+       }
+
+       /* Handle TX events as appropiate, the correct place to do this is
+        * in a tx routine. Perhaps TX on epn was pre-empted by ep0
+        */
+
+       if (usbp->usber & USB_E_TXB) {
+               usbp->usber |= USB_E_TXB;
+       }
+
+       if (usbp->usber & (USB_TX_ERRMASK)) {
+               mpc8xx_udc_handle_txerr ();
+       }
+
+       /* Switch to the default state, respond at the default address */
+       if (usbp->usber & USB_E_RESET) {
+               usbp->usber |= USB_E_RESET;
+               usbp->usaddr = 0x00;
+               udc_device->device_state = STATE_DEFAULT;
+       }
+
+       /* if(usbp->usber&USB_E_IDLE){
+          We could suspend here !
+          usbp->usber|=USB_E_IDLE;
+          DBG("idle state change\n");
+          }
+          if(usbp->usbs){
+          We could resume here when IDLE is deasserted !
+          Not worth doing, so long as we are self powered though.
+          }
+       */
+
+       return;
+}
+
+/* udc_endpoint_write
+ *
+ * Write some data to an endpoint
+ */
+int udc_endpoint_write (struct usb_endpoint_instance *epi)
+{
+       int ep = 0;
+       short epid = 1, unnak = 0, ret = 0;
+
+       if (udc_state != STATE_READY) {
+               ERR ("invalid udc_state != STATE_READY!\n");
+               return -1;
+       }
+
+       if (!udc_device || !epi) {
+               return -1;
+       }
+
+       if (udc_device->device_state != STATE_CONFIGURED) {
+               return -1;
+       }
+
+       ep = epi->endpoint_address & 0x03;
+       if (ep >= MAX_ENDPOINTS) {
+               return -1;
+       }
+
+       /* Set NAK for all RX endpoints during TX */
+       for (epid = 1; epid < MAX_ENDPOINTS; epid++) {
+
+               /* Don't set NAK on DATA IN/CONTROL endpoints */
+               if (ep_ref[epid].sc & USB_DIR_IN) {
+                       continue;
+               }
+
+               if (!(usbp->usep[epid] & (USEP_THS_NAK | USEP_RHS_NAK))) {
+                       unnak |= 1 << epid;
+               }
+
+               mpc8xx_udc_set_nak (epid);
+       }
+
+       mpc8xx_udc_init_tx (&udc_device->bus->endpoint_array[ep],
+                           epi->tx_urb);
+       ret = mpc8xx_udc_ep_tx (&udc_device->bus->endpoint_array[ep]);
+
+       /* Remove temporary NAK */
+       for (epid = 1; epid < MAX_ENDPOINTS; epid++) {
+               if (unnak & (1 << epid)) {
+                       udc_unset_nak (epid);
+               }
+       }
+
+       return ret;
+}
+
+/* mpc8xx_udc_assign_urb
+ *
+ * Associate a given urb to an endpoint TX or RX transmit/receive buffers
+ */
+static int mpc8xx_udc_assign_urb (int ep, char direction)
+{
+       struct usb_endpoint_instance *epi = 0;
+
+       if (ep >= MAX_ENDPOINTS) {
+               goto err;
+       }
+       epi = &udc_device->bus->endpoint_array[ep];
+       if (!epi) {
+               goto err;
+       }
+
+       if (!ep_ref[ep].urb) {
+               ep_ref[ep].urb = usbd_alloc_urb (udc_device, udc_device->bus->endpoint_array);
+               if (!ep_ref[ep].urb) {
+                       goto err;
+               }
+       } else {
+               ep_ref[ep].urb->actual_length = 0;
+       }
+
+       switch (direction) {
+       case USB_DIR_IN:
+               epi->tx_urb = ep_ref[ep].urb;
+               break;
+       case USB_DIR_OUT:
+               epi->rcv_urb = ep_ref[ep].urb;
+               break;
+       default:
+               goto err;
+       }
+       return 0;
+
+      err:
+       udc_state = STATE_ERROR;
+       return -1;
+}
+
+/* udc_setup_ep
+ *
+ * Associate U-Boot software endpoints to mpc8xx endpoint parameter ram
+ * Isochronous endpoints aren't yet supported!
+ */
+void udc_setup_ep (struct usb_device_instance *device, unsigned int ep,
+                  struct usb_endpoint_instance *epi)
+{
+       uchar direction = 0;
+       int ep_attrib = 0;
+
+       if (epi && (ep < MAX_ENDPOINTS)) {
+
+               if (ep == 0) {
+                       if (epi->rcv_attributes != USB_ENDPOINT_XFER_CONTROL
+                           || epi->tx_attributes !=
+                           USB_ENDPOINT_XFER_CONTROL) {
+
+                               /* ep0 must be a control endpoint */
+                               udc_state = STATE_ERROR;
+                               return;
+
+                       }
+                       if (!(ep_ref[ep].sc & EP_ATTACHED)) {
+                               mpc8xx_udc_cbd_attach (ep, epi->tx_packetSize,
+                                                      epi->rcv_packetSize);
+                       }
+                       usbp->usep[ep] = 0x0000;
+                       return;
+               }
+
+               if ((epi->endpoint_address & USB_ENDPOINT_DIR_MASK)
+                   == USB_DIR_IN) {
+
+                       direction = 1;
+                       ep_attrib = epi->tx_attributes;
+                       epi->rcv_packetSize = 0;
+                       ep_ref[ep].sc |= USB_DIR_IN;
+               } else {
+
+                       direction = 0;
+                       ep_attrib = epi->rcv_attributes;
+                       epi->tx_packetSize = 0;
+                       ep_ref[ep].sc &= ~USB_DIR_IN;
+               }
+
+               if (mpc8xx_udc_assign_urb (ep, epi->endpoint_address
+                                          & USB_ENDPOINT_DIR_MASK)) {
+                       return;
+               }
+
+               switch (ep_attrib) {
+               case USB_ENDPOINT_XFER_CONTROL:
+                       if (!(ep_ref[ep].sc & EP_ATTACHED)) {
+                               mpc8xx_udc_cbd_attach (ep,
+                                                      epi->tx_packetSize,
+                                                      epi->rcv_packetSize);
+                       }
+                       usbp->usep[ep] = ep << 12;
+                       epi->rcv_urb = epi->tx_urb = ep_ref[ep].urb;
+
+                       break;
+               case USB_ENDPOINT_XFER_BULK:
+               case USB_ENDPOINT_XFER_INT:
+                       if (!(ep_ref[ep].sc & EP_ATTACHED)) {
+                               if (direction) {
+                                       mpc8xx_udc_cbd_attach (ep,
+                                                              epi->tx_packetSize,
+                                                              0);
+                               } else {
+                                       mpc8xx_udc_cbd_attach (ep,
+                                                              0,
+                                                              epi->rcv_packetSize);
+                               }
+                       }
+                       usbp->usep[ep] = (ep << 12) | ((ep_attrib) << 8);
+
+                       break;
+               case USB_ENDPOINT_XFER_ISOC:
+               default:
+                       serial_printf ("Error endpoint attrib %d>3\n", ep_attrib);
+                       udc_state = STATE_ERROR;
+                       break;
+               }
+       }
+
+}
+
+/* udc_connect
+ *
+ * Move state, switch on the USB
+ */
+void udc_connect (void)
+{
+       /* Enable pull-up resistor on D+
+        * TODO: fit a pull-up resistor to drive SE0 for > 2.5us
+        */
+
+       if (udc_state != STATE_ERROR) {
+               udc_state = STATE_READY;
+               usbp->usmod |= USMOD_EN;
+       }
+}
+
+/* udc_disconnect
+ *
+ * Disconnect is not used but, is included for completeness
+ */
+void udc_disconnect (void)
+{
+       /* Disable pull-up resistor on D-
+        * TODO: fix a pullup resistor to control this
+        */
+
+       if (udc_state != STATE_ERROR) {
+               udc_state = STATE_NOT_READY;
+       }
+       usbp->usmod &= ~USMOD_EN;
+}
+
+/* udc_enable
+ *
+ * Grab an EP0 URB, register interest in a subset of USB events
+ */
+void udc_enable (struct usb_device_instance *device)
+{
+       if (udc_state == STATE_ERROR) {
+               return;
+       }
+
+       udc_device = device;
+
+       if (!ep_ref[0].urb) {
+               ep_ref[0].urb = usbd_alloc_urb (device, device->bus->endpoint_array);
+       }
+
+       /* Register interest in all events except SOF, enable transceiver */
+       usbp->usber = 0x03FF;
+       usbp->usbmr = 0x02F7;
+
+       return;
+}
+
+/* udc_disable
+ *
+ * disable the currently hooked device
+ */
+void udc_disable (void)
+{
+       int i = 0;
+
+       if (udc_state == STATE_ERROR) {
+               DBG ("Won't disable UDC. udc_state==STATE_ERROR !\n");
+               return;
+       }
+
+       udc_device = 0;
+
+       for (; i < MAX_ENDPOINTS; i++) {
+               if (ep_ref[i].urb) {
+                       usbd_dealloc_urb (ep_ref[i].urb);
+                       ep_ref[i].urb = 0;
+               }
+       }
+
+       usbp->usbmr = 0x00;
+       usbp->usmod = ~USMOD_EN;
+       udc_state = STATE_NOT_READY;
+}
+
+/* udc_startup_events
+ *
+ * Enable the specified device
+ */
+void udc_startup_events (struct usb_device_instance *device)
+{
+       udc_enable (device);
+       if (udc_state == STATE_READY) {
+               usbd_device_event_irq (device, DEVICE_CREATE, 0);
+       }
+}
+
+/* udc_set_nak
+ *
+ * Allow upper layers to signal lower layers should not accept more RX data
+ *
+ */
+void udc_set_nak (int epid)
+{
+       if (epid) {
+               mpc8xx_udc_set_nak (epid);
+       }
+}
+
+/* udc_unset_nak
+ *
+ * Suspend sending of NAK tokens for DATA OUT tokens on a given endpoint.
+ * Switch off NAKing on this endpoint to accept more data output from host.
+ *
+ */
+void udc_unset_nak (int epid)
+{
+       if (epid > MAX_ENDPOINTS) {
+               return;
+       }
+
+       if (usbp->usep[epid] & (USEP_THS_NAK | USEP_RHS_NAK)) {
+               usbp->usep[epid] &= ~(USEP_THS_NAK | USEP_RHS_NAK);
+               __asm__ ("eieio");
+       }
+}
+
+/******************************************************************************
+                             Static Linkage
+******************************************************************************/
+
+/* udc_state_transition_up
+ * udc_state_transition_down
+ *
+ * Helper functions to implement device state changes. The device states and
+ * the events that transition between them are:
+ *
+ *                             STATE_ATTACHED
+ *                             ||      /\
+ *                             \/      ||
+ *     DEVICE_HUB_CONFIGURED                   DEVICE_HUB_RESET
+ *                             ||      /\
+ *                             \/      ||
+ *                             STATE_POWERED
+ *                             ||      /\
+ *                             \/      ||
+ *     DEVICE_RESET                            DEVICE_POWER_INTERRUPTION
+ *                             ||      /\
+ *                             \/      ||
+ *                             STATE_DEFAULT
+ *                             ||      /\
+ *                             \/      ||
+ *     DEVICE_ADDRESS_ASSIGNED                 DEVICE_RESET
+ *                             ||      /\
+ *                             \/      ||
+ *                             STATE_ADDRESSED
+ *                             ||      /\
+ *                             \/      ||
+ *     DEVICE_CONFIGURED                       DEVICE_DE_CONFIGURED
+ *                             ||      /\
+ *                             \/      ||
+ *                             STATE_CONFIGURED
+ *
+ * udc_state_transition_up transitions up (in the direction from STATE_ATTACHED
+ * to STATE_CONFIGURED) from the specified initial state to the specified final
+ * state, passing through each intermediate state on the way.  If the initial
+ * state is at or above (i.e. nearer to STATE_CONFIGURED) the final state, then
+ * no state transitions will take place.
+ *
+ * udc_state_transition_down transitions down (in the direction from
+ * STATE_CONFIGURED to STATE_ATTACHED) from the specified initial state to the
+ * specified final state, passing through each intermediate state on the way.
+ * If the initial state is at or below (i.e. nearer to STATE_ATTACHED) the final
+ * state, then no state transitions will take place.
+ *
+ */
+
+static void mpc8xx_udc_state_transition_up (usb_device_state_t initial,
+                                           usb_device_state_t final)
+{
+       if (initial < final) {
+               switch (initial) {
+               case STATE_ATTACHED:
+                       usbd_device_event_irq (udc_device,
+                                              DEVICE_HUB_CONFIGURED, 0);
+                       if (final == STATE_POWERED)
+                               break;
+               case STATE_POWERED:
+                       usbd_device_event_irq (udc_device, DEVICE_RESET, 0);
+                       if (final == STATE_DEFAULT)
+                               break;
+               case STATE_DEFAULT:
+                       usbd_device_event_irq (udc_device,
+                                              DEVICE_ADDRESS_ASSIGNED, 0);
+                       if (final == STATE_ADDRESSED)
+                               break;
+               case STATE_ADDRESSED:
+                       usbd_device_event_irq (udc_device, DEVICE_CONFIGURED,
+                                              0);
+               case STATE_CONFIGURED:
+                       break;
+               default:
+                       break;
+               }
+       }
+}
+
+static void mpc8xx_udc_state_transition_down (usb_device_state_t initial,
+                                             usb_device_state_t final)
+{
+       if (initial > final) {
+               switch (initial) {
+               case STATE_CONFIGURED:
+                       usbd_device_event_irq (udc_device,
+                                              DEVICE_DE_CONFIGURED, 0);
+                       if (final == STATE_ADDRESSED)
+                               break;
+               case STATE_ADDRESSED:
+                       usbd_device_event_irq (udc_device, DEVICE_RESET, 0);
+                       if (final == STATE_DEFAULT)
+                               break;
+               case STATE_DEFAULT:
+                       usbd_device_event_irq (udc_device,
+                                              DEVICE_POWER_INTERRUPTION, 0);
+                       if (final == STATE_POWERED)
+                               break;
+               case STATE_POWERED:
+                       usbd_device_event_irq (udc_device, DEVICE_HUB_RESET,
+                                              0);
+               case STATE_ATTACHED:
+                       break;
+               default:
+                       break;
+               }
+       }
+}
+
+/* mpc8xx_udc_stall
+ *
+ * Force returning of STALL tokens on the given endpoint. Protocol or function
+ * STALL conditions are permissable here
+ */
+static void mpc8xx_udc_stall (unsigned int ep)
+{
+       usbp->usep[ep] |= STALL_BITMASK;
+}
+
+/* mpc8xx_udc_set_nak
+ *
+ * Force returning of NAK responses for the given endpoint as a kind of very
+ * simple flow control
+ */
+static void mpc8xx_udc_set_nak (unsigned int ep)
+{
+       usbp->usep[ep] |= NAK_BITMASK;
+       __asm__ ("eieio");
+}
+
+/* mpc8xx_udc_handle_txerr
+ *
+ * Handle errors relevant to TX. Return a status code to allow calling
+ * indicative of what if anything happened
+ */
+static short mpc8xx_udc_handle_txerr ()
+{
+       short ep = 0, ret = 0;
+
+       for (; ep < TX_RING_SIZE; ep++) {
+               if (usbp->usber & (0x10 << ep)) {
+
+                       /* Timeout or underrun */
+                       if (tx_cbd[ep]->cbd_sc & 0x06) {
+                               ret = 1;
+                               mpc8xx_udc_flush_tx_fifo (ep);
+
+                       } else {
+                               if (usbp->usep[ep] & STALL_BITMASK) {
+                                       if (!ep) {
+                                               usbp->usep[ep] &= ~STALL_BITMASK;
+                                       }
+                               }       /* else NAK */
+                       }
+                       usbp->usber |= (0x10 << ep);
+               }
+       }
+       return ret;
+}
+
+/* mpc8xx_udc_advance_rx
+ *
+ * Advance cbd rx
+ */
+static void mpc8xx_udc_advance_rx (volatile cbd_t ** rx_cbdp, int epid)
+{
+       if ((*rx_cbdp)->cbd_sc & RX_BD_W) {
+               *rx_cbdp = (volatile cbd_t *) (endpoints[epid]->rbase + CONFIG_SYS_IMMR);
+
+       } else {
+               (*rx_cbdp)++;
+       }
+}
+
+
+/* mpc8xx_udc_flush_tx_fifo
+ *
+ * Flush a given TX fifo. Assumes one tx cbd per endpoint
+ */
+static void mpc8xx_udc_flush_tx_fifo (int epid)
+{
+       volatile cbd_t *tx_cbdp = 0;
+
+       if (epid > MAX_ENDPOINTS) {
+               return;
+       }
+
+       /* TX stop */
+       immr->im_cpm.cp_cpcr = ((epid << 2) | 0x1D01);
+       __asm__ ("eieio");
+       while (immr->im_cpm.cp_cpcr & 0x01);
+
+       usbp->uscom = 0x40 | 0;
+
+       /* reset ring */
+       tx_cbdp = (cbd_t *) (endpoints[epid]->tbptr + CONFIG_SYS_IMMR);
+       tx_cbdp->cbd_sc = (TX_BD_I | TX_BD_W);
+
+
+       endpoints[epid]->tptr = endpoints[epid]->tbase;
+       endpoints[epid]->tstate = 0x00;
+       endpoints[epid]->tbcnt = 0x00;
+
+       /* TX start */
+       immr->im_cpm.cp_cpcr = ((epid << 2) | 0x2D01);
+       __asm__ ("eieio");
+       while (immr->im_cpm.cp_cpcr & 0x01);
+
+       return;
+}
+
+/* mpc8xx_udc_flush_rx_fifo
+ *
+ * For the sake of completeness of the namespace, it seems like
+ * a good-design-decision (tm) to include mpc8xx_udc_flush_rx_fifo();
+ * If RX_BD_E is true => a driver bug either here or in an upper layer
+ * not polling frequently enough. If RX_BD_E is true we have told the host
+ * we have accepted data but, the CPM found it had no-where to put that data
+ * which needless to say would be a bad thing.
+ */
+static void mpc8xx_udc_flush_rx_fifo ()
+{
+       int i = 0;
+
+       for (i = 0; i < RX_RING_SIZE; i++) {
+               if (!(rx_cbd[i]->cbd_sc & RX_BD_E)) {
+                       ERR ("buf %p used rx data len = 0x%x sc=0x%x!\n",
+                            rx_cbd[i], rx_cbd[i]->cbd_datlen,
+                            rx_cbd[i]->cbd_sc);
+
+               }
+       }
+       ERR ("BUG : Input over-run\n");
+}
+
+/* mpc8xx_udc_clear_rxbd
+ *
+ * Release control of RX CBD to CP.
+ */
+static void mpc8xx_udc_clear_rxbd (volatile cbd_t * rx_cbdp)
+{
+       rx_cbdp->cbd_datlen = 0x0000;
+       rx_cbdp->cbd_sc = ((rx_cbdp->cbd_sc & RX_BD_W) | (RX_BD_E | RX_BD_I));
+       __asm__ ("eieio");
+}
+
+/* mpc8xx_udc_tx_irq
+ *
+ * Parse for tx timeout, control RX or USB reset/busy conditions
+ * Return -1 on timeout, -2 on fatal error, else return zero
+ */
+static int mpc8xx_udc_tx_irq (int ep)
+{
+       int i = 0;
+
+       if (usbp->usber & (USB_TX_ERRMASK)) {
+               if (mpc8xx_udc_handle_txerr ()) {
+                       /* Timeout, controlling function must retry send */
+                       return -1;
+               }
+       }
+
+       if (usbp->usber & (USB_E_RESET | USB_E_BSY)) {
+               /* Fatal, abandon TX transaction */
+               return -2;
+       }
+
+       if (usbp->usber & USB_E_RXB) {
+               for (i = 0; i < RX_RING_SIZE; i++) {
+                       if (!(rx_cbd[i]->cbd_sc & RX_BD_E)) {
+                               if ((rx_cbd[i] == ep_ref[0].prx) || ep) {
+                                       return -2;
+                               }
+                       }
+               }
+       }
+
+       return 0;
+}
+
+/* mpc8xx_udc_ep_tx
+ *
+ * Transmit in a re-entrant fashion outbound USB packets.
+ * Implement retry/timeout mechanism described in USB specification
+ * Toggle DATA0/DATA1 pids as necessary
+ * Introduces non-standard tx_retry. The USB standard has no scope for slave
+ * devices to give up TX, however tx_retry stops us getting stuck in an endless
+ * TX loop.
+ */
+static int mpc8xx_udc_ep_tx (struct usb_endpoint_instance *epi)
+{
+       struct urb *urb = epi->tx_urb;
+       volatile cbd_t *tx_cbdp = 0;
+       unsigned int ep = 0, pkt_len = 0, x = 0, tx_retry = 0;
+       int ret = 0;
+
+       if (!epi || (epi->endpoint_address & 0x03) >= MAX_ENDPOINTS || !urb) {
+               return -1;
+       }
+
+       ep = epi->endpoint_address & 0x03;
+       tx_cbdp = (cbd_t *) (endpoints[ep]->tbptr + CONFIG_SYS_IMMR);
+
+       if (tx_cbdp->cbd_sc & TX_BD_R || usbp->usber & USB_E_TXB) {
+               mpc8xx_udc_flush_tx_fifo (ep);
+               usbp->usber |= USB_E_TXB;
+       };
+
+       while (tx_retry++ < 100) {
+               ret = mpc8xx_udc_tx_irq (ep);
+               if (ret == -1) {
+                       /* ignore timeout here */
+               } else if (ret == -2) {
+                       /* Abandon TX */
+                       mpc8xx_udc_flush_tx_fifo (ep);
+                       return -1;
+               }
+
+               tx_cbdp = (cbd_t *) (endpoints[ep]->tbptr + CONFIG_SYS_IMMR);
+               while (tx_cbdp->cbd_sc & TX_BD_R) {
+               };
+               tx_cbdp->cbd_sc = (tx_cbdp->cbd_sc & TX_BD_W);
+
+               pkt_len = urb->actual_length - epi->sent;
+
+               if (pkt_len > epi->tx_packetSize || pkt_len > EP_MAX_PKT) {
+                       pkt_len = MIN (epi->tx_packetSize, EP_MAX_PKT);
+               }
+
+               for (x = 0; x < pkt_len; x++) {
+                       *((unsigned char *) (tx_cbdp->cbd_bufaddr + x)) =
+                               urb->buffer[epi->sent + x];
+               }
+               tx_cbdp->cbd_datlen = pkt_len;
+               tx_cbdp->cbd_sc |= (CBD_TX_BITMASK | ep_ref[ep].pid);
+               __asm__ ("eieio");
+
+#ifdef __SIMULATE_ERROR__
+               if (++err_poison_test == 2) {
+                       err_poison_test = 0;
+                       tx_cbdp->cbd_sc &= ~TX_BD_TC;
+               }
+#endif
+
+               usbp->uscom = (USCOM_STR | ep);
+
+               while (!(usbp->usber & USB_E_TXB)) {
+                       ret = mpc8xx_udc_tx_irq (ep);
+                       if (ret == -1) {
+                               /* TX timeout */
+                               break;
+                       } else if (ret == -2) {
+                               if (usbp->usber & USB_E_TXB) {
+                                       usbp->usber |= USB_E_TXB;
+                               }
+                               mpc8xx_udc_flush_tx_fifo (ep);
+                               return -1;
+                       }
+               };
+
+               if (usbp->usber & USB_E_TXB) {
+                       usbp->usber |= USB_E_TXB;
+               }
+
+               /* ACK must be present <= 18bit times from TX */
+               if (ret == -1) {
+                       continue;
+               }
+
+               /* TX ACK : USB 2.0 8.7.2, Toggle PID, Advance TX */
+               epi->sent += pkt_len;
+               epi->last = MIN (urb->actual_length - epi->sent, epi->tx_packetSize);
+               TOGGLE_TX_PID (ep_ref[ep].pid);
+
+               if (epi->sent >= epi->tx_urb->actual_length) {
+
+                       epi->tx_urb->actual_length = 0;
+                       epi->sent = 0;
+
+                       if (ep_ref[ep].sc & EP_SEND_ZLP) {
+                               ep_ref[ep].sc &= ~EP_SEND_ZLP;
+                       } else {
+                               return 0;
+                       }
+               }
+       }
+
+       ERR ("TX fail, endpoint 0x%x tx bytes 0x%x/0x%x\n", ep, epi->sent,
+            epi->tx_urb->actual_length);
+
+       return -1;
+}
+
+/* mpc8xx_udc_dump_request
+ *
+ * Dump a control request to console
+ */
+static void mpc8xx_udc_dump_request (struct usb_device_request *request)
+{
+       DBG ("bmRequestType:%02x bRequest:%02x wValue:%04x "
+            "wIndex:%04x wLength:%04x ?\n",
+            request->bmRequestType,
+            request->bRequest,
+            request->wValue, request->wIndex, request->wLength);
+
+       return;
+}
+
+/* mpc8xx_udc_ep0_rx_setup
+ *
+ * Decode received ep0 SETUP packet. return non-zero on error
+ */
+static int mpc8xx_udc_ep0_rx_setup (volatile cbd_t * rx_cbdp)
+{
+       unsigned int x = 0;
+       struct urb *purb = ep_ref[0].urb;
+       struct usb_endpoint_instance *epi =
+               &udc_device->bus->endpoint_array[0];
+
+       for (; x < rx_cbdp->cbd_datlen; x++) {
+               *(((unsigned char *) &ep_ref[0].urb->device_request) + x) =
+                       *((unsigned char *) (rx_cbdp->cbd_bufaddr + x));
+       }
+
+       mpc8xx_udc_clear_rxbd (rx_cbdp);
+
+       if (ep0_recv_setup (purb)) {
+               mpc8xx_udc_dump_request (&purb->device_request);
+               return -1;
+       }
+
+       if ((purb->device_request.bmRequestType & USB_REQ_DIRECTION_MASK)
+           == USB_REQ_HOST2DEVICE) {
+
+               switch (purb->device_request.bRequest) {
+               case USB_REQ_SET_ADDRESS:
+                       /* Send the Status OUT ZLP */
+                       ep_ref[0].pid = TX_BD_PID_DATA1;
+                       purb->actual_length = 0;
+                       mpc8xx_udc_init_tx (epi, purb);
+                       mpc8xx_udc_ep_tx (epi);
+
+                       /* Move to the addressed state */
+                       usbp->usaddr = udc_device->address;
+                       mpc8xx_udc_state_transition_up (udc_device->device_state,
+                                                       STATE_ADDRESSED);
+                       return 0;
+
+               case USB_REQ_SET_CONFIGURATION:
+                       if (!purb->device_request.wValue) {
+                               /* Respond at default address */
+                               usbp->usaddr = 0x00;
+                               mpc8xx_udc_state_transition_down (udc_device->device_state,
+                                                                 STATE_ADDRESSED);
+                       } else {
+                               /* TODO: Support multiple configurations */
+                               mpc8xx_udc_state_transition_up (udc_device->device_state,
+                                                               STATE_CONFIGURED);
+                               for (x = 1; x < MAX_ENDPOINTS; x++) {
+                                       if ((udc_device->bus->endpoint_array[x].endpoint_address & USB_ENDPOINT_DIR_MASK)
+                                           == USB_DIR_IN) {
+                                               ep_ref[x].pid = TX_BD_PID_DATA0;
+                                       } else {
+                                               ep_ref[x].pid = RX_BD_PID_DATA0;
+                                       }
+                                       /* Set configuration must unstall endpoints */
+                                       usbp->usep[x] &= ~STALL_BITMASK;
+                               }
+                       }
+                       break;
+               default:
+                       /* CDC/Vendor specific */
+                       break;
+               }
+
+               /* Send ZLP as ACK in Status OUT phase */
+               ep_ref[0].pid = TX_BD_PID_DATA1;
+               purb->actual_length = 0;
+               mpc8xx_udc_init_tx (epi, purb);
+               mpc8xx_udc_ep_tx (epi);
+
+       } else {
+
+               if (purb->actual_length) {
+                       ep_ref[0].pid = TX_BD_PID_DATA1;
+                       mpc8xx_udc_init_tx (epi, purb);
+
+                       if (!(purb->actual_length % EP0_MAX_PACKET_SIZE)) {
+                               ep_ref[0].sc |= EP_SEND_ZLP;
+                       }
+
+                       if (purb->device_request.wValue ==
+                           USB_DESCRIPTOR_TYPE_DEVICE) {
+                               if (le16_to_cpu (purb->device_request.wLength)
+                                   > purb->actual_length) {
+                                       /* Send EP0_MAX_PACKET_SIZE bytes
+                                        * unless correct size requested.
+                                        */
+                                       if (purb->actual_length > epi->tx_packetSize) {
+                                               purb->actual_length = epi->tx_packetSize;
+                                       }
+                               }
+                       }
+                       mpc8xx_udc_ep_tx (epi);
+
+               } else {
+                       /* Corrupt SETUP packet? */
+                       ERR ("Zero length data or SETUP with DATA-IN phase ?\n");
+                       return 1;
+               }
+       }
+       return 0;
+}
+
+/* mpc8xx_udc_init_tx
+ *
+ * Setup some basic parameters for a TX transaction
+ */
+static void mpc8xx_udc_init_tx (struct usb_endpoint_instance *epi,
+                               struct urb *tx_urb)
+{
+       epi->sent = 0;
+       epi->last = 0;
+       epi->tx_urb = tx_urb;
+}
+
+/* mpc8xx_udc_ep0_rx
+ *
+ * Receive ep0/control USB data. Parse and possibly send a response.
+ */
+static void mpc8xx_udc_ep0_rx (volatile cbd_t * rx_cbdp)
+{
+       if (rx_cbdp->cbd_sc & RX_BD_PID_SETUP) {
+
+               /* Unconditionally accept SETUP packets */
+               if (mpc8xx_udc_ep0_rx_setup (rx_cbdp)) {
+                       mpc8xx_udc_stall (0);
+               }
+
+       } else {
+
+               mpc8xx_udc_clear_rxbd (rx_cbdp);
+
+               if ((rx_cbdp->cbd_datlen - 2)) {
+                       /* SETUP with a DATA phase
+                        * outside of SETUP packet.
+                        * Reply with STALL.
+                        */
+                       mpc8xx_udc_stall (0);
+               }
+       }
+}
+
+/* mpc8xx_udc_epn_rx
+ *
+ * Receive some data from cbd into USB system urb data abstraction
+ * Upper layers should NAK if there is insufficient RX data space
+ */
+static int mpc8xx_udc_epn_rx (unsigned int epid, volatile cbd_t * rx_cbdp)
+{
+       struct usb_endpoint_instance *epi = 0;
+       struct urb *urb = 0;
+       unsigned int x = 0;
+
+       if (epid >= MAX_ENDPOINTS || !rx_cbdp->cbd_datlen) {
+               return 0;
+       }
+
+       /* USB 2.0 PDF section 8.6.4
+        * Discard data with invalid PID it is a resend.
+        */
+       if (ep_ref[epid].pid != (rx_cbdp->cbd_sc & 0xC0)) {
+               return 1;
+       }
+       TOGGLE_RX_PID (ep_ref[epid].pid);
+
+       epi = &udc_device->bus->endpoint_array[epid];
+       urb = epi->rcv_urb;
+
+       for (; x < (rx_cbdp->cbd_datlen - 2); x++) {
+               *((unsigned char *) (urb->buffer + urb->actual_length + x)) =
+                       *((unsigned char *) (rx_cbdp->cbd_bufaddr + x));
+       }
+
+       if (x) {
+               usbd_rcv_complete (epi, x, 0);
+               if (ep_ref[epid].urb->status == RECV_ERROR) {
+                       DBG ("RX error unset NAK\n");
+                       udc_unset_nak (epid);
+               }
+       }
+       return x;
+}
+
+/* mpc8xx_udc_clock_init
+ *
+ * Obtain a clock reference for Full Speed Signaling
+ */
+static void mpc8xx_udc_clock_init (volatile immap_t * immr,
+                                  volatile cpm8xx_t * cp)
+{
+
+#if defined(CONFIG_SYS_USB_EXTC_CLK)
+
+       /* This has been tested with a 48MHz crystal on CLK6 */
+       switch (CONFIG_SYS_USB_EXTC_CLK) {
+       case 1:
+               immr->im_ioport.iop_papar |= 0x0100;
+               immr->im_ioport.iop_padir &= ~0x0100;
+               cp->cp_sicr |= 0x24;
+               break;
+       case 2:
+               immr->im_ioport.iop_papar |= 0x0200;
+               immr->im_ioport.iop_padir &= ~0x0200;
+               cp->cp_sicr |= 0x2D;
+               break;
+       case 3:
+               immr->im_ioport.iop_papar |= 0x0400;
+               immr->im_ioport.iop_padir &= ~0x0400;
+               cp->cp_sicr |= 0x36;
+               break;
+       case 4:
+               immr->im_ioport.iop_papar |= 0x0800;
+               immr->im_ioport.iop_padir &= ~0x0800;
+               cp->cp_sicr |= 0x3F;
+               break;
+       default:
+               udc_state = STATE_ERROR;
+               break;
+       }
+
+#elif defined(CONFIG_SYS_USB_BRGCLK)
+
+       /* This has been tested with brgclk == 50MHz */
+       int divisor = 0;
+
+       if (gd->cpu_clk < 48000000L) {
+               ERR ("brgclk is too slow for full-speed USB!\n");
+               udc_state = STATE_ERROR;
+               return;
+       }
+
+       /* Assume the brgclk is 'good enough', we want !(gd->cpu_clk%48MHz)
+        * but, can /probably/ live with close-ish alternative rates.
+        */
+       divisor = (gd->cpu_clk / 48000000L) - 1;
+       cp->cp_sicr &= ~0x0000003F;
+
+       switch (CONFIG_SYS_USB_BRGCLK) {
+       case 1:
+               cp->cp_brgc1 |= (divisor | CPM_BRG_EN);
+               cp->cp_sicr &= ~0x2F;
+               break;
+       case 2:
+               cp->cp_brgc2 |= (divisor | CPM_BRG_EN);
+               cp->cp_sicr |= 0x00000009;
+               break;
+       case 3:
+               cp->cp_brgc3 |= (divisor | CPM_BRG_EN);
+               cp->cp_sicr |= 0x00000012;
+               break;
+       case 4:
+               cp->cp_brgc4 = (divisor | CPM_BRG_EN);
+               cp->cp_sicr |= 0x0000001B;
+               break;
+       default:
+               udc_state = STATE_ERROR;
+               break;
+       }
+
+#else
+#error "CONFIG_SYS_USB_EXTC_CLK or CONFIG_SYS_USB_BRGCLK must be defined"
+#endif
+
+}
+
+/* mpc8xx_udc_cbd_attach
+ *
+ * attach a cbd to and endpoint
+ */
+static void mpc8xx_udc_cbd_attach (int ep, uchar tx_size, uchar rx_size)
+{
+
+       if (!tx_cbd[ep] || !rx_cbd[ep] || ep >= MAX_ENDPOINTS) {
+               udc_state = STATE_ERROR;
+               return;
+       }
+
+       if (tx_size > USB_MAX_PKT || rx_size > USB_MAX_PKT ||
+           (!tx_size && !rx_size)) {
+               udc_state = STATE_ERROR;
+               return;
+       }
+
+       /* Attach CBD to appropiate Parameter RAM Endpoint data structure */
+       if (rx_size) {
+               endpoints[ep]->rbase = (u32) rx_cbd[rx_ct];
+               endpoints[ep]->rbptr = (u32) rx_cbd[rx_ct];
+               rx_ct++;
+
+               if (!ep) {
+
+                       endpoints[ep]->rbptr = (u32) rx_cbd[rx_ct];
+                       rx_cbd[rx_ct]->cbd_sc |= RX_BD_W;
+                       rx_ct++;
+
+               } else {
+                       rx_ct += 2;
+                       endpoints[ep]->rbptr = (u32) rx_cbd[rx_ct];
+                       rx_cbd[rx_ct]->cbd_sc |= RX_BD_W;
+                       rx_ct++;
+               }
+
+               /* Where we expect to RX data on this endpoint */
+               ep_ref[ep].prx = rx_cbd[rx_ct - 1];
+       } else {
+
+               ep_ref[ep].prx = 0;
+               endpoints[ep]->rbase = 0;
+               endpoints[ep]->rbptr = 0;
+       }
+
+       if (tx_size) {
+               endpoints[ep]->tbase = (u32) tx_cbd[tx_ct];
+               endpoints[ep]->tbptr = (u32) tx_cbd[tx_ct];
+               tx_ct++;
+       } else {
+               endpoints[ep]->tbase = 0;
+               endpoints[ep]->tbptr = 0;
+       }
+
+       endpoints[ep]->tstate = 0;
+       endpoints[ep]->tbcnt = 0;
+       endpoints[ep]->mrblr = EP_MAX_PKT;
+       endpoints[ep]->rfcr = 0x18;
+       endpoints[ep]->tfcr = 0x18;
+       ep_ref[ep].sc |= EP_ATTACHED;
+
+       DBG ("ep %d rbase 0x%08x rbptr 0x%08x tbase 0x%08x tbptr 0x%08x prx = %p\n",
+               ep, endpoints[ep]->rbase, endpoints[ep]->rbptr,
+               endpoints[ep]->tbase, endpoints[ep]->tbptr,
+               ep_ref[ep].prx);
+
+       return;
+}
+
+/* mpc8xx_udc_cbd_init
+ *
+ * Allocate space for a cbd and allocate TX/RX data space
+ */
+static void mpc8xx_udc_cbd_init (void)
+{
+       int i = 0;
+
+       for (; i < TX_RING_SIZE; i++) {
+               tx_cbd[i] = (cbd_t *)
+                       mpc8xx_udc_alloc (sizeof (cbd_t), sizeof (int));
+       }
+
+       for (i = 0; i < RX_RING_SIZE; i++) {
+               rx_cbd[i] = (cbd_t *)
+                       mpc8xx_udc_alloc (sizeof (cbd_t), sizeof (int));
+       }
+
+       for (i = 0; i < TX_RING_SIZE; i++) {
+               tx_cbd[i]->cbd_bufaddr =
+                       mpc8xx_udc_alloc (EP_MAX_PKT, sizeof (int));
+
+               tx_cbd[i]->cbd_sc = (TX_BD_I | TX_BD_W);
+               tx_cbd[i]->cbd_datlen = 0x0000;
+       }
+
+
+       for (i = 0; i < RX_RING_SIZE; i++) {
+               rx_cbd[i]->cbd_bufaddr =
+                       mpc8xx_udc_alloc (EP_MAX_PKT, sizeof (int));
+               rx_cbd[i]->cbd_sc = (RX_BD_I | RX_BD_E);
+               rx_cbd[i]->cbd_datlen = 0x0000;
+
+       }
+
+       return;
+}
+
+/* mpc8xx_udc_endpoint_init
+ *
+ * Attach an endpoint to some dpram
+ */
+static void mpc8xx_udc_endpoint_init (void)
+{
+       int i = 0;
+
+       for (; i < MAX_ENDPOINTS; i++) {
+               endpoints[i] = (usb_epb_t *)
+                       mpc8xx_udc_alloc (sizeof (usb_epb_t), 32);
+       }
+}
+
+/* mpc8xx_udc_alloc
+ *
+ * Grab the address of some dpram
+ */
+static u32 mpc8xx_udc_alloc (u32 data_size, u32 alignment)
+{
+       u32 retaddr = address_base;
+
+       while (retaddr % alignment) {
+               retaddr++;
+       }
+       address_base += data_size;
+
+       return retaddr;
+}