USB: amd5536 UDC driver (in GEODE southbridge)

Driver for the AMD5536 UDC, as found in the AMD Geode CS5536 (southbridge).
This is a high speed DMA-capable controller, which can also be used in
OTG configurations (which are not supported by this patch).

Acked-by: Jordan Crouse <jordan.crouse@amd.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

6 files changed, 4114 insertions, 0 deletions

diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig
index 45e01e28945..1553e9a649c 100644
--- a/drivers/usb/gadget/Kconfig
+++ b/drivers/usb/gadget/Kconfig
@@ -82,6 +82,27 @@ choice
 	   Many controller drivers are platform-specific; these
 	   often need board-specific hooks.
 
+config USB_GADGET_AMD5536UDC
+	boolean "AMD5536 UDC"
+	depends on PCI
+	select USB_GADGET_DUALSPEED
+	help
+	   The AMD5536 UDC is part of the AMD Geode CS5536, an x86 southbridge.
+	   It is a USB Highspeed DMA capable USB device controller. Beside ep0
+	   it provides 4 IN and 4 OUT endpoints (bulk or interrupt type).
+	   The UDC port supports OTG operation, and may be used as a host port
+	   if it's not being used to implement peripheral or OTG roles.
+
+	   Say "y" to link the driver statically, or "m" to build a
+	   dynamically linked module called "amd5536udc" and force all
+	   gadget drivers to also be dynamically linked.
+
+config USB_AMD5536UDC
+	tristate
+	depends on USB_GADGET_AMD5536UDC
+	default USB_GADGET
+	select USB_GADGET_SELECTED
+
 config USB_GADGET_FSL_USB2
 	boolean "Freescale Highspeed USB DR Peripheral Controller"
 	depends on MPC834x || PPC_MPC831x
diff --git a/drivers/usb/gadget/Makefile b/drivers/usb/gadget/Makefile
index 8ae76f73863..1bc0f03550c 100644
--- a/drivers/usb/gadget/Makefile
+++ b/drivers/usb/gadget/Makefile
@@ -7,6 +7,7 @@ endif
 
 obj-$(CONFIG_USB_DUMMY_HCD)	+= dummy_hcd.o
 obj-$(CONFIG_USB_NET2280)	+= net2280.o
+obj-$(CONFIG_USB_AMD5536UDC)	+= amd5536udc.o
 obj-$(CONFIG_USB_PXA2XX)	+= pxa2xx_udc.o
 obj-$(CONFIG_USB_GOKU)		+= goku_udc.o
 obj-$(CONFIG_USB_OMAP)		+= omap_udc.o
diff --git a/drivers/usb/gadget/amd5536udc.c b/drivers/usb/gadget/amd5536udc.c
new file mode 100644
index 00000000000..714156ca8fe
--- /dev/null
+++ b/drivers/usb/gadget/amd5536udc.c
@@ -0,0 +1,3454 @@
+/*
+ * amd5536.c -- AMD 5536 UDC high/full speed USB device controller
+ *
+ * Copyright (C) 2005-2007 AMD (http://www.amd.com)
+ * Author: Thomas Dahlmann
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+/*
+ * The AMD5536 UDC is part of the x86 southbridge AMD Geode CS5536.
+ * It is a USB Highspeed DMA capable USB device controller. Beside ep0 it
+ * provides 4 IN and 4 OUT endpoints (bulk or interrupt type).
+ *
+ * Make sure that UDC is assigned to port 4 by BIOS settings (port can also
+ * be used as host port) and UOC bits PAD_EN and APU are set (should be done
+ * by BIOS init).
+ *
+ * UDC DMA requires 32-bit aligned buffers so DMA with gadget ether does not
+ * work without updating NET_IP_ALIGN. Or PIO mode (module param "use_dma=0")
+ * can be used with gadget ether.
+ */
+
+/* debug control */
+/* #define UDC_VERBOSE */
+
+/* Driver strings */
+#define UDC_MOD_DESCRIPTION		"AMD 5536 UDC - USB Device Controller"
+#define UDC_DRIVER_VERSION_STRING	"01.00.0206 - $Revision: #3 $"
+
+/* system */
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/kernel.h>
+#include <linux/version.h>
+#include <linux/delay.h>
+#include <linux/ioport.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/smp_lock.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/timer.h>
+#include <linux/list.h>
+#include <linux/interrupt.h>
+#include <linux/ioctl.h>
+#include <linux/fs.h>
+#include <linux/dmapool.h>
+#include <linux/moduleparam.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+
+#include <asm/byteorder.h>
+#include <asm/system.h>
+#include <asm/unaligned.h>
+
+/* gadget stack */
+#include <linux/usb/ch9.h>
+#include <linux/usb_gadget.h>
+
+/* udc specific */
+#include "amd5536udc.h"
+
+
+static void udc_tasklet_disconnect(unsigned long);
+static void empty_req_queue(struct udc_ep *);
+static int udc_probe(struct udc *dev);
+static void udc_basic_init(struct udc *dev);
+static void udc_setup_endpoints(struct udc *dev);
+static void udc_soft_reset(struct udc *dev);
+static struct udc_request *udc_alloc_bna_dummy(struct udc_ep *ep);
+static void udc_free_request(struct usb_ep *usbep, struct usb_request *usbreq);
+static int udc_free_dma_chain(struct udc *dev, struct udc_request *req);
+static int udc_create_dma_chain(struct udc_ep *ep, struct udc_request *req,
+				unsigned long buf_len, gfp_t gfp_flags);
+static int udc_remote_wakeup(struct udc *dev);
+static int udc_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id);
+static void udc_pci_remove(struct pci_dev *pdev);
+
+/* description */
+static const char mod_desc[] = UDC_MOD_DESCRIPTION;
+static const char name[] = "amd5536udc";
+
+/* structure to hold endpoint function pointers */
+static const struct usb_ep_ops udc_ep_ops;
+
+/* received setup data */
+static union udc_setup_data setup_data;
+
+/* pointer to device object */
+static struct udc *udc;
+
+/* irq spin lock for soft reset */
+static DEFINE_SPINLOCK(udc_irq_spinlock);
+/* stall spin lock */
+static DEFINE_SPINLOCK(udc_stall_spinlock);
+
+/*
+* slave mode: pending bytes in rx fifo after nyet,
+* used if EPIN irq came but no req was available
+*/
+static unsigned int udc_rxfifo_pending;
+
+/* count soft resets after suspend to avoid loop */
+static int soft_reset_occured;
+static int soft_reset_after_usbreset_occured;
+
+/* timer */
+static struct timer_list udc_timer;
+static int stop_timer;
+
+/* set_rde -- Is used to control enabling of RX DMA. Problem is
+ * that UDC has only one bit (RDE) to enable/disable RX DMA for
+ * all OUT endpoints. So we have to handle race conditions like
+ * when OUT data reaches the fifo but no request was queued yet.
+ * This cannot be solved by letting the RX DMA disabled until a
+ * request gets queued because there may be other OUT packets
+ * in the FIFO (important for not blocking control traffic).
+ * The value of set_rde controls the correspondig timer.
+ *
+ * set_rde -1 == not used, means it is alloed to be set to 0 or 1
+ * set_rde  0 == do not touch RDE, do no start the RDE timer
+ * set_rde  1 == timer function will look whether FIFO has data
+ * set_rde  2 == set by timer function to enable RX DMA on next call
+ */
+static int set_rde = -1;
+
+static DECLARE_COMPLETION(on_exit);
+static struct timer_list udc_pollstall_timer;
+static int stop_pollstall_timer;
+static DECLARE_COMPLETION(on_pollstall_exit);
+
+/* tasklet for usb disconnect */
+static DECLARE_TASKLET(disconnect_tasklet, udc_tasklet_disconnect,
+		(unsigned long) &udc);
+
+
+/* endpoint names used for print */
+static const char ep0_string[] = "ep0in";
+static const char *ep_string[] = {
+	ep0_string,
+	"ep1in-int", "ep2in-bulk", "ep3in-bulk", "ep4in-bulk", "ep5in-bulk",
+	"ep6in-bulk", "ep7in-bulk", "ep8in-bulk", "ep9in-bulk", "ep10in-bulk",
+	"ep11in-bulk", "ep12in-bulk", "ep13in-bulk", "ep14in-bulk",
+	"ep15in-bulk", "ep0out", "ep1out-bulk", "ep2out-bulk", "ep3out-bulk",
+	"ep4out-bulk", "ep5out-bulk", "ep6out-bulk", "ep7out-bulk",
+	"ep8out-bulk", "ep9out-bulk", "ep10out-bulk", "ep11out-bulk",
+	"ep12out-bulk", "ep13out-bulk", "ep14out-bulk", "ep15out-bulk"
+};
+
+/* DMA usage flag */
+static int use_dma = 1;
+/* packet per buffer dma */
+static int use_dma_ppb = 1;
+/* with per descr. update */
+static int use_dma_ppb_du;
+/* buffer fill mode */
+static int use_dma_bufferfill_mode;
+/* full speed only mode */
+static int use_fullspeed;
+/* tx buffer size for high speed */
+static unsigned long hs_tx_buf = UDC_EPIN_BUFF_SIZE;
+
+/* module parameters */
+module_param(use_dma, bool, S_IRUGO);
+MODULE_PARM_DESC(use_dma, "true for DMA");
+module_param(use_dma_ppb, bool, S_IRUGO);
+MODULE_PARM_DESC(use_dma_ppb, "true for DMA in packet per buffer mode");
+module_param(use_dma_ppb_du, bool, S_IRUGO);
+MODULE_PARM_DESC(use_dma_ppb_du,
+	"true for DMA in packet per buffer mode with descriptor update");
+module_param(use_fullspeed, bool, S_IRUGO);
+MODULE_PARM_DESC(use_fullspeed, "true for fullspeed only");
+
+/*---------------------------------------------------------------------------*/
+/* Prints UDC device registers and endpoint irq registers */
+static void print_regs(struct udc *dev)
+{
+	DBG(dev, "------- Device registers -------\n");
+	DBG(dev, "dev config     = %08x\n", readl(&dev->regs->cfg));
+	DBG(dev, "dev control    = %08x\n", readl(&dev->regs->ctl));
+	DBG(dev, "dev status     = %08x\n", readl(&dev->regs->sts));
+	DBG(dev, "\n");
+	DBG(dev, "dev int's      = %08x\n", readl(&dev->regs->irqsts));
+	DBG(dev, "dev intmask    = %08x\n", readl(&dev->regs->irqmsk));
+	DBG(dev, "\n");
+	DBG(dev, "dev ep int's   = %08x\n", readl(&dev->regs->ep_irqsts));
+	DBG(dev, "dev ep intmask = %08x\n", readl(&dev->regs->ep_irqmsk));
+	DBG(dev, "\n");
+	DBG(dev, "USE DMA        = %d\n", use_dma);
+	if (use_dma && use_dma_ppb && !use_dma_ppb_du) {
+		DBG(dev, "DMA mode       = PPBNDU (packet per buffer "
+			"WITHOUT desc. update)\n");
+		dev_info(&dev->pdev->dev, "DMA mode (%s)\n", "PPBNDU");
+	} else if (use_dma && use_dma_ppb_du && use_dma_ppb_du) {
+		DBG(dev, "DMA mode       = PPBDU (packet per buffer "
+			"WITH desc. update)\n");
+		dev_info(&dev->pdev->dev, "DMA mode (%s)\n", "PPBDU");
+	}
+	if (use_dma && use_dma_bufferfill_mode) {
+		DBG(dev, "DMA mode       = BF (buffer fill mode)\n");
+		dev_info(&dev->pdev->dev, "DMA mode (%s)\n", "BF");
+	}
+	if (!use_dma) {
+		dev_info(&dev->pdev->dev, "FIFO mode\n");
+	}
+	DBG(dev, "-------------------------------------------------------\n");
+}
+
+/* Masks unused interrupts */
+static int udc_mask_unused_interrupts(struct udc *dev)
+{
+	u32 tmp;
+
+	/* mask all dev interrupts */
+	tmp =	AMD_BIT(UDC_DEVINT_SVC) |
+		AMD_BIT(UDC_DEVINT_ENUM) |
+		AMD_BIT(UDC_DEVINT_US) |
+		AMD_BIT(UDC_DEVINT_UR) |
+		AMD_BIT(UDC_DEVINT_ES) |
+		AMD_BIT(UDC_DEVINT_SI) |
+		AMD_BIT(UDC_DEVINT_SOF)|
+		AMD_BIT(UDC_DEVINT_SC);
+	writel(tmp, &dev->regs->irqmsk);
+
+	/* mask all ep interrupts */
+	writel(UDC_EPINT_MSK_DISABLE_ALL, &dev->regs->ep_irqmsk);
+
+	return 0;
+}
+
+/* Enables endpoint 0 interrupts */
+static int udc_enable_ep0_interrupts(struct udc *dev)
+{
+	u32 tmp;
+
+	DBG(dev, "udc_enable_ep0_interrupts()\n");
+
+	/* read irq mask */
+	tmp = readl(&dev->regs->ep_irqmsk);
+	/* enable ep0 irq's */
+	tmp &= AMD_UNMASK_BIT(UDC_EPINT_IN_EP0)
+		& AMD_UNMASK_BIT(UDC_EPINT_OUT_EP0);
+	writel(tmp, &dev->regs->ep_irqmsk);
+
+	return 0;
+}
+
+/* Enables device interrupts for SET_INTF and SET_CONFIG */
+static int udc_enable_dev_setup_interrupts(struct udc *dev)
+{
+	u32 tmp;
+
+	DBG(dev, "enable device interrupts for setup data\n");
+
+	/* read irq mask */
+	tmp = readl(&dev->regs->irqmsk);
+
+	/* enable SET_INTERFACE, SET_CONFIG and other needed irq's */
+	tmp &= AMD_UNMASK_BIT(UDC_DEVINT_SI)
+		& AMD_UNMASK_BIT(UDC_DEVINT_SC)
+		& AMD_UNMASK_BIT(UDC_DEVINT_UR)
+		& AMD_UNMASK_BIT(UDC_DEVINT_SVC)
+		& AMD_UNMASK_BIT(UDC_DEVINT_ENUM);
+	writel(tmp, &dev->regs->irqmsk);
+
+	return 0;
+}
+
+/* Calculates fifo start of endpoint based on preceeding endpoints */
+static int udc_set_txfifo_addr(struct udc_ep *ep)
+{
+	struct udc	*dev;
+	u32 tmp;
+	int i;
+
+	if (!ep || !(ep->in))
+		return -EINVAL;
+
+	dev = ep->dev;
+	ep->txfifo = dev->txfifo;
+
+	/* traverse ep's */
+	for (i = 0; i < ep->num; i++) {
+		if (dev->ep[i].regs) {
+			/* read fifo size */
+			tmp = readl(&dev->ep[i].regs->bufin_framenum);
+			tmp = AMD_GETBITS(tmp, UDC_EPIN_BUFF_SIZE);
+			ep->txfifo += tmp;
+		}
+	}
+	return 0;
+}
+
+/* CNAK pending field: bit0 = ep0in, bit16 = ep0out */
+static u32 cnak_pending;
+
+static void UDC_QUEUE_CNAK(struct udc_ep *ep, unsigned num)
+{
+	if (readl(&ep->regs->ctl) & AMD_BIT(UDC_EPCTL_NAK)) {
+		DBG(ep->dev, "NAK could not be cleared for ep%d\n", num);
+		cnak_pending |= 1 << (num);
+		ep->naking = 1;
+	} else
+		cnak_pending = cnak_pending & (~(1 << (num)));
+}
+
+
+/* Enables endpoint, is called by gadget driver */
+static int
+udc_ep_enable(struct usb_ep *usbep, const struct usb_endpoint_descriptor *desc)
+{
+	struct udc_ep		*ep;
+	struct udc		*dev;
+	u32			tmp;
+	unsigned long		iflags;
+	u8 udc_csr_epix;
+
+	if (!usbep
+			|| usbep->name == ep0_string
+			|| !desc
+			|| desc->bDescriptorType != USB_DT_ENDPOINT)
+		return -EINVAL;
+
+	ep = container_of(usbep, struct udc_ep, ep);
+	dev = ep->dev;
+
+	DBG(dev, "udc_ep_enable() ep %d\n", ep->num);
+
+	if (!dev->driver || dev->gadget.speed == USB_SPEED_UNKNOWN)
+		return -ESHUTDOWN;
+
+	spin_lock_irqsave(&dev->lock, iflags);
+	ep->desc = desc;
+
+	ep->halted = 0;
+
+	/* set traffic type */
+	tmp = readl(&dev->ep[ep->num].regs->ctl);
+	tmp = AMD_ADDBITS(tmp, desc->bmAttributes, UDC_EPCTL_ET);
+	writel(tmp, &dev->ep[ep->num].regs->ctl);
+
+	/* set max packet size */
+	tmp = readl(&dev->ep[ep->num].regs->bufout_maxpkt);
+	tmp = AMD_ADDBITS(tmp, desc->wMaxPacketSize, UDC_EP_MAX_PKT_SIZE);
+	ep->ep.maxpacket = desc->wMaxPacketSize;
+	writel(tmp, &dev->ep[ep->num].regs->bufout_maxpkt);
+
+	/* IN ep */
+	if (ep->in) {
+
+		/* ep ix in UDC CSR register space */
+		udc_csr_epix = ep->num;
+
+		/* set buffer size (tx fifo entries) */
+		tmp = readl(&dev->ep[ep->num].regs->bufin_framenum);
+		/* double buffering: fifo size = 2 x max packet size */
+		tmp = AMD_ADDBITS(
+				tmp,
+				desc->wMaxPacketSize * UDC_EPIN_BUFF_SIZE_MULT
+						/ UDC_DWORD_BYTES,
+				UDC_EPIN_BUFF_SIZE);
+		writel(tmp, &dev->ep[ep->num].regs->bufin_framenum);
+
+		/* calc. tx fifo base addr */
+		udc_set_txfifo_addr(ep);
+
+		/* flush fifo */
+		tmp = readl(&ep->regs->ctl);
+		tmp |= AMD_BIT(UDC_EPCTL_F);
+		writel(tmp, &ep->regs->ctl);
+
+	/* OUT ep */
+	} else {
+		/* ep ix in UDC CSR register space */
+		udc_csr_epix = ep->num - UDC_CSR_EP_OUT_IX_OFS;
+
+		/* set max packet size UDC CSR	*/
+		tmp = readl(&dev->csr->ne[ep->num - UDC_CSR_EP_OUT_IX_OFS]);
+		tmp = AMD_ADDBITS(tmp, desc->wMaxPacketSize,
+					UDC_CSR_NE_MAX_PKT);
+		writel(tmp, &dev->csr->ne[ep->num - UDC_CSR_EP_OUT_IX_OFS]);
+
+		if (use_dma && !ep->in) {
+			/* alloc and init BNA dummy request */
+			ep->bna_dummy_req = udc_alloc_bna_dummy(ep);
+			ep->bna_occurred = 0;
+		}
+
+		if (ep->num != UDC_EP0OUT_IX)
+			dev->data_ep_enabled = 1;
+	}
+
+	/* set ep values */
+	tmp = readl(&dev->csr->ne[udc_csr_epix]);
+	/* max packet */
+	tmp = AMD_ADDBITS(tmp, desc->wMaxPacketSize, UDC_CSR_NE_MAX_PKT);
+	/* ep number */
+	tmp = AMD_ADDBITS(tmp, desc->bEndpointAddress, UDC_CSR_NE_NUM);
+	/* ep direction */
+	tmp = AMD_ADDBITS(tmp, ep->in, UDC_CSR_NE_DIR);
+	/* ep type */
+	tmp = AMD_ADDBITS(tmp, desc->bmAttributes, UDC_CSR_NE_TYPE);
+	/* ep config */
+	tmp = AMD_ADDBITS(tmp, ep->dev->cur_config, UDC_CSR_NE_CFG);
+	/* ep interface */
+	tmp = AMD_ADDBITS(tmp, ep->dev->cur_intf, UDC_CSR_NE_INTF);
+	/* ep alt */
+	tmp = AMD_ADDBITS(tmp, ep->dev->cur_alt, UDC_CSR_NE_ALT);
+	/* write reg */
+	writel(tmp, &dev->csr->ne[udc_csr_epix]);
+
+	/* enable ep irq */
+	tmp = readl(&dev->regs->ep_irqmsk);
+	tmp &= AMD_UNMASK_BIT(ep->num);
+	writel(tmp, &dev->regs->ep_irqmsk);
+
+	/*
+	 * clear NAK by writing CNAK
+	 * avoid BNA for OUT DMA, don't clear NAK until DMA desc. written
+	 */
+	if (!use_dma || ep->in) {
+		tmp = readl(&ep->regs->ctl);
+		tmp |= AMD_BIT(UDC_EPCTL_CNAK);
+		writel(tmp, &ep->regs->ctl);
+		ep->naking = 0;
+		UDC_QUEUE_CNAK(ep, ep->num);
+	}
+	tmp = desc->bEndpointAddress;
+	DBG(dev, "%s enabled\n", usbep->name);
+
+	spin_unlock_irqrestore(&dev->lock, iflags);
+	return 0;
+}
+
+/* Resets endpoint */
+static void ep_init(struct udc_regs __iomem *regs, struct udc_ep *ep)
+{
+	u32		tmp;
+
+	VDBG(ep->dev, "ep-%d reset\n", ep->num);
+	ep->desc = NULL;
+	ep->ep.ops = &udc_ep_ops;
+	INIT_LIST_HEAD(&ep->queue);
+
+	ep->ep.maxpacket = (u16) ~0;
+	/* set NAK */
+	tmp = readl(&ep->regs->ctl);
+	tmp |= AMD_BIT(UDC_EPCTL_SNAK);
+	writel(tmp, &ep->regs->ctl);
+	ep->naking = 1;
+
+	/* disable interrupt */
+	tmp = readl(&regs->ep_irqmsk);
+	tmp |= AMD_BIT(ep->num);
+	writel(tmp, &regs->ep_irqmsk);
+
+	if (ep->in) {
+		/* unset P and IN bit of potential former DMA */
+		tmp = readl(&ep->regs->ctl);
+		tmp &= AMD_UNMASK_BIT(UDC_EPCTL_P);
+		writel(tmp, &ep->regs->ctl);
+
+		tmp = readl(&ep->regs->sts);
+		tmp |= AMD_BIT(UDC_EPSTS_IN);
+		writel(tmp, &ep->regs->sts);
+
+		/* flush the fifo */
+		tmp = readl(&ep->regs->ctl);
+		tmp |= AMD_BIT(UDC_EPCTL_F);
+		writel(tmp, &ep->regs->ctl);
+
+	}
+	/* reset desc pointer */
+	writel(0, &ep->regs->desptr);
+}
+
+/* Disables endpoint, is called by gadget driver */
+static int udc_ep_disable(struct usb_ep *usbep)
+{
+	struct udc_ep	*ep = NULL;
+	unsigned long	iflags;
+
+	if (!usbep)
+		return -EINVAL;
+
+	ep = container_of(usbep, struct udc_ep, ep);
+	if (usbep->name == ep0_string || !ep->desc)
+		return -EINVAL;
+
+	DBG(ep->dev, "Disable ep-%d\n", ep->num);
+
+	spin_lock_irqsave(&ep->dev->lock, iflags);
+	udc_free_request(&ep->ep, &ep->bna_dummy_req->req);
+	empty_req_queue(ep);
+	ep_init(ep->dev->regs, ep);
+	spin_unlock_irqrestore(&ep->dev->lock, iflags);
+
+	return 0;
+}
+
+/* Allocates request packet, called by gadget driver */
+static struct usb_request *
+udc_alloc_request(struct usb_ep *usbep, gfp_t gfp)
+{
+	struct udc_request	*req;
+	struct udc_data_dma	*dma_desc;
+	struct udc_ep	*ep;
+
+	if (!usbep)
+		return NULL;
+
+	ep = container_of(usbep, struct udc_ep, ep);
+
+	VDBG(ep->dev, "udc_alloc_req(): ep%d\n", ep->num);
+	req = kzalloc(sizeof(struct udc_request), gfp);
+	if (!req)
+		return NULL;
+
+	req->req.dma = DMA_DONT_USE;
+	INIT_LIST_HEAD(&req->queue);
+
+	if (ep->dma) {
+		/* ep0 in requests are allocated from data pool here */
+		dma_desc = pci_pool_alloc(ep->dev->data_requests, gfp,
+						&req->td_phys);
+		if (!dma_desc) {
+			kfree(req);
+			return NULL;
+		}
+
+		VDBG(ep->dev, "udc_alloc_req: req = %p dma_desc = %p, "
+				"td_phys = %lx\n",
+				req, dma_desc,
+				(unsigned long)req->td_phys);
+		/* prevent from using desc. - set HOST BUSY */
+		dma_desc->status = AMD_ADDBITS(dma_desc->status,
+						UDC_DMA_STP_STS_BS_HOST_BUSY,
+						UDC_DMA_STP_STS_BS);
+		dma_desc->bufptr = __constant_cpu_to_le32(DMA_DONT_USE);
+		req->td_data = dma_desc;
+		req->td_data_last = NULL;
+		req->chain_len = 1;
+	}
+
+	return &req->req;
+}
+
+/* Frees request packet, called by gadget driver */
+static void
+udc_free_request(struct usb_ep *usbep, struct usb_request *usbreq)
+{
+	struct udc_ep	*ep;
+	struct udc_request	*req;
+
+	if (!usbep || !usbreq)
+		return;
+
+	ep = container_of(usbep, struct udc_ep, ep);
+	req = container_of(usbreq, struct udc_request, req);
+	VDBG(ep->dev, "free_req req=%p\n", req);
+	BUG_ON(!list_empty(&req->queue));
+	if (req->td_data) {
+		VDBG(ep->dev, "req->td_data=%p\n", req->td_data);
+
+		/* free dma chain if created */
+		if (req->chain_len > 1) {
+			udc_free_dma_chain(ep->dev, req);
+		}
+
+		pci_pool_free(ep->dev->data_requests, req->td_data,
+							req->td_phys);
+	}
+	kfree(req);
+}
+
+/* Init BNA dummy descriptor for HOST BUSY and pointing to itself */
+static void udc_init_bna_dummy(struct udc_request *req)
+{
+	if (req) {
+		/* set last bit */
+		req->td_data->status |= AMD_BIT(UDC_DMA_IN_STS_L);
+		/* set next pointer to itself */
+		req->td_data->next = req->td_phys;
+		/* set HOST BUSY */
+		req->td_data->status
+			= AMD_ADDBITS(req->td_data->status,
+					UDC_DMA_STP_STS_BS_DMA_DONE,
+					UDC_DMA_STP_STS_BS);
+#ifdef UDC_VERBOSE
+		pr_debug("bna desc = %p, sts = %08x\n",
+			req->td_data, req->td_data->status);
+#endif
+	}
+}
+
+/* Allocate BNA dummy descriptor */
+static struct udc_request *udc_alloc_bna_dummy(struct udc_ep *ep)
+{
+	struct udc_request *req = NULL;
+	struct usb_request *_req = NULL;
+
+	/* alloc the dummy request */
+	_req = udc_alloc_request(&ep->ep, GFP_ATOMIC);
+	if (_req) {
+		req = container_of(_req, struct udc_request, req);
+		ep->bna_dummy_req = req;
+		udc_init_bna_dummy(req);
+	}
+	return req;
+}
+
+/* Write data to TX fifo for IN packets */
+static void
+udc_txfifo_write(struct udc_ep *ep, struct usb_request *req)
+{
+	u8			*req_buf;
+	u32			*buf;
+	int			i, j;
+	unsigned		bytes = 0;
+	unsigned		remaining = 0;
+
+	if (!req || !ep)
+		return;
+
+	req_buf = req->buf + req->actual;
+	prefetch(req_buf);
+	remaining = req->length - req->actual;
+
+	buf = (u32 *) req_buf;
+
+	bytes = ep->ep.maxpacket;
+	if (bytes > remaining)
+		bytes = remaining;
+
+	/* dwords first */
+	for (i = 0; i < bytes / UDC_DWORD_BYTES; i++) {
+		writel(*(buf + i), ep->txfifo);
+	}
+
+	/* remaining bytes must be written by byte access */
+	for (j = 0; j < bytes % UDC_DWORD_BYTES; j++) {
+		writeb((u8)(*(buf + i) >> (j << UDC_BITS_PER_BYTE_SHIFT)),
+							ep->txfifo);
+	}
+
+	/* dummy write confirm */
+	writel(0, &ep->regs->confirm);
+}
+
+/* Read dwords from RX fifo for OUT transfers */
+static int udc_rxfifo_read_dwords(struct udc *dev, u32 *buf, int dwords)
+{
+	int i;
+
+	VDBG(dev, "udc_read_dwords(): %d dwords\n", dwords);
+
+	for (i = 0; i < dwords; i++) {
+		*(buf + i) = readl(dev->rxfifo);
+	}
+	return 0;
+}
+
+/* Read bytes from RX fifo for OUT transfers */
+static int udc_rxfifo_read_bytes(struct udc *dev, u8 *buf, int bytes)
+{
+	int i, j;
+	u32 tmp;
+
+	VDBG(dev, "udc_read_bytes(): %d bytes\n", bytes);
+
+	/* dwords first */
+	for (i = 0; i < bytes / UDC_DWORD_BYTES; i++) {
+		*((u32 *)(buf + (i<<2))) = readl(dev->rxfifo);
+	}
+
+	/* remaining bytes must be read by byte access */
+	if (bytes % UDC_DWORD_BYTES) {
+		tmp = readl(dev->rxfifo);
+		for (j = 0; j < bytes % UDC_DWORD_BYTES; j++) {
+			*(buf + (i<<2) + j) = (u8)(tmp & UDC_BYTE_MASK);
+			tmp = tmp >> UDC_BITS_PER_BYTE;
+		}
+	}
+
+	return 0;
+}
+
+/* Read data from RX fifo for OUT transfers */
+static int
+udc_rxfifo_read(struct udc_ep *ep, struct udc_request *req)
+{
+	u8 *buf;
+	unsigned buf_space;
+	unsigned bytes = 0;
+	unsigned finished = 0;
+
+	/* received number bytes */
+	bytes = readl(&ep->regs->sts);
+	bytes = AMD_GETBITS(bytes, UDC_EPSTS_RX_PKT_SIZE);
+
+	buf_space = req->req.length - req->req.actual;
+	buf = req->req.buf + req->req.actual;
+	if (bytes > buf_space) {
+		if ((buf_space % ep->ep.maxpacket) != 0) {
+			DBG(ep->dev,
+				"%s: rx %d bytes, rx-buf space = %d bytesn\n",
+				ep->ep.name, bytes, buf_space);
+			req->req.status = -EOVERFLOW;
+		}
+		bytes = buf_space;
+	}
+	req->req.actual += bytes;
+
+	/* last packet ? */
+	if (((bytes % ep->ep.maxpacket) != 0) || (!bytes)
+		|| ((req->req.actual == req->req.length) && !req->req.zero))
+		finished = 1;
+
+	/* read rx fifo bytes */
+	VDBG(ep->dev, "ep %s: rxfifo read %d bytes\n", ep->ep.name, bytes);
+	udc_rxfifo_read_bytes(ep->dev, buf, bytes);
+
+	return finished;
+}
+
+/* create/re-init a DMA descriptor or a DMA descriptor chain */
+static int prep_dma(struct udc_ep *ep, struct udc_request *req, gfp_t gfp)
+{
+	int	retval = 0;
+	u32	tmp;
+
+	VDBG(ep->dev, "prep_dma\n");
+	VDBG(ep->dev, "prep_dma ep%d req->td_data=%p\n",
+			ep->num, req->td_data);
+
+	/* set buffer pointer */
+	req->td_data->bufptr = req->req.dma;
+
+	/* set last bit */
+	req->td_data->status |= AMD_BIT(UDC_DMA_IN_STS_L);
+
+	/* build/re-init dma chain if maxpkt scatter mode, not for EP0 */
+	if (use_dma_ppb) {
+
+		retval = udc_create_dma_chain(ep, req, ep->ep.maxpacket, gfp);
+		if (retval != 0) {
+			if (retval == -ENOMEM)
+				DBG(ep->dev, "Out of DMA memory\n");
+			return retval;
+		}
+		if (ep->in) {
+			if (req->req.length == ep->ep.maxpacket) {
+				/* write tx bytes */
+				req->td_data->status =
+					AMD_ADDBITS(req->td_data->status,
+						ep->ep.maxpacket,
+						UDC_DMA_IN_STS_TXBYTES);
+
+			}
+		}
+
+	}
+
+	if (ep->in) {
+		VDBG(ep->dev, "IN: use_dma_ppb=%d req->req.len=%d "
+				"maxpacket=%d ep%d\n",
+				use_dma_ppb, req->req.length,
+				ep->ep.maxpacket, ep->num);
+		/*
+		 * if bytes < max packet then tx bytes must
+		 * be written in packet per buffer mode
+		 */
+		if (!use_dma_ppb || req->req.length < ep->ep.maxpacket
+				|| ep->num == UDC_EP0OUT_IX
+				|| ep->num == UDC_EP0IN_IX) {
+			/* write tx bytes */
+			req->td_data->status =
+				AMD_ADDBITS(req->td_data->status,
+						req->req.length,
+						UDC_DMA_IN_STS_TXBYTES);
+			/* reset frame num */
+			req->td_data->status =
+				AMD_ADDBITS(req->td_data->status,
+						0,
+						UDC_DMA_IN_STS_FRAMENUM);
+		}
+		/* set HOST BUSY */
+		req->td_data->status =
+			AMD_ADDBITS(req->td_data->status,
+				UDC_DMA_STP_STS_BS_HOST_BUSY,
+				UDC_DMA_STP_STS_BS);
+	} else {
+		VDBG(ep->dev, "OUT set host ready\n");
+		/* set HOST READY */
+		req->td_data->status =
+			AMD_ADDBITS(req->td_data->status,
+				UDC_DMA_STP_STS_BS_HOST_READY,
+				UDC_DMA_STP_STS_BS);
+
+
+			/* clear NAK by writing CNAK */
+			if (ep->naking) {
+				tmp = readl(&ep->regs->ctl);
+				tmp |= AMD_BIT(UDC_EPCTL_CNAK);
+				writel(tmp, &ep->regs->ctl);
+				ep->naking = 0;
+				UDC_QUEUE_CNAK(ep, ep->num);
+			}
+
+	}
+
+	return retval;
+}
+
+/* Completes request packet ... caller MUST hold lock */
+static void
+complete_req(struct udc_ep *ep, struct udc_request *req, int sts)
+__releases(ep->dev->lock)
+__acquires(ep->dev->lock)
+{
+	struct udc		*dev;
+	unsigned		halted;
+
+	VDBG(ep->dev, "complete_req(): ep%d\n", ep->num);
+
+	dev = ep->dev;
+	/* unmap DMA */
+	if (req->dma_mapping) {
+		if (ep->in)
+			pci_unmap_single(dev->pdev,
+					req->req.dma,
+					req->req.length,
+					PCI_DMA_TODEVICE);
+		else
+			pci_unmap_single(dev->pdev,
+					req->req.dma,
+					req->req.length,
+					PCI_DMA_FROMDEVICE);
+		req->dma_mapping = 0;
+		req->req.dma = DMA_DONT_USE;
+	}
+
+	halted = ep->halted;
+	ep->halted = 1;
+
+	/* set new status if pending */
+	if (req->req.status == -EINPROGRESS)
+		req->req.status = sts;
+
+	/* remove from ep queue */
+	list_del_init(&req->queue);
+
+	VDBG(ep->dev, "req %p => complete %d bytes at %s with sts %d\n",
+		&req->req, req->req.length, ep->ep.name, sts);
+
+	spin_unlock(&dev->lock);
+	req->req.complete(&ep->ep, &req->req);
+	spin_lock(&dev->lock);
+	ep->halted = halted;
+}
+
+/* frees pci pool descriptors of a DMA chain */
+static int udc_free_dma_chain(struct udc *dev, struct udc_request *req)
+{
+
+	int ret_val = 0;
+	struct udc_data_dma	*td;
+	struct udc_data_dma	*td_last = NULL;
+	unsigned int i;
+
+	DBG(dev, "free chain req = %p\n", req);
+
+	/* do not free first desc., will be done by free for request */
+	td_last = req->td_data;
+	td = phys_to_virt(td_last->next);
+
+	for (i = 1; i < req->chain_len; i++) {
+
+		pci_pool_free(dev->data_requests, td,
+				(dma_addr_t) td_last->next);
+		td_last = td;
+		td = phys_to_virt(td_last->next);
+	}
+
+	return ret_val;
+}
+
+/* Iterates to the end of a DMA chain and returns last descriptor */
+static struct udc_data_dma *udc_get_last_dma_desc(struct udc_request *req)
+{
+	struct udc_data_dma	*td;
+
+	td = req->td_data;
+	while (td && !(td->status & AMD_BIT(UDC_DMA_IN_STS_L))) {
+		td = phys_to_virt(td->next);
+	}
+
+	return td;
+
+}
+
+/* Iterates to the end of a DMA chain and counts bytes received */
+static u32 udc_get_ppbdu_rxbytes(struct udc_request *req)
+{
+	struct udc_data_dma	*td;
+	u32 count;
+
+	td = req->td_data;
+	/* received number bytes */
+	count = AMD_GETBITS(td->status, UDC_DMA_OUT_STS_RXBYTES);
+
+	while (td && !(td->status & AMD_BIT(UDC_DMA_IN_STS_L))) {
+		td = phys_to_virt(td->next);
+		/* received number bytes */
+		if (td) {
+			count += AMD_GETBITS(td->status,
+				UDC_DMA_OUT_STS_RXBYTES);
+		}
+	}
+
+	return count;
+
+}
+
+/* Creates or re-inits a DMA chain */
+static int udc_create_dma_chain(
+	struct udc_ep *ep,
+	struct udc_request *req,
+	unsigned long buf_len, gfp_t gfp_flags
+)
+{
+	unsigned long bytes = req->req.length;
+	unsigned int i;
+	dma_addr_t dma_addr;
+	struct udc_data_dma	*td = NULL;
+	struct udc_data_dma	*last = NULL;
+	unsigned long txbytes;
+	unsigned create_new_chain = 0;
+	unsigned len;
+
+	VDBG(ep->dev, "udc_create_dma_chain: bytes=%ld buf_len=%ld\n",
+			bytes, buf_len);
+	dma_addr = DMA_DONT_USE;
+
+	/* unset L bit in first desc for OUT */
+	if (!ep->in) {
+		req->td_data->status &= AMD_CLEAR_BIT(UDC_DMA_IN_STS_L);
+	}
+
+	/* alloc only new desc's if not already available */
+	len = req->req.length / ep->ep.maxpacket;
+	if (req->req.length % ep->ep.maxpacket) {
+		len++;
+	}
+
+	if (len > req->chain_len) {
+		/* shorter chain already allocated before */
+		if (req->chain_len > 1) {
+			udc_free_dma_chain(ep->dev, req);
+		}
+		req->chain_len = len;
+		create_new_chain = 1;
+	}
+
+	td = req->td_data;
+	/* gen. required number of descriptors and buffers */
+	for (i = buf_len; i < bytes; i += buf_len) {
+		/* create or determine next desc. */
+		if (create_new_chain) {
+
+			td = pci_pool_alloc(ep->dev->data_requests,
+					gfp_flags, &dma_addr);
+			if (!td)
+				return -ENOMEM;
+
+			td->status = 0;
+		} else if (i == buf_len) {
+			/* first td */
+			td = (struct udc_data_dma *) phys_to_virt(
+						req->td_data->next);
+			td->status = 0;
+		} else {
+			td = (struct udc_data_dma *) phys_to_virt(last->next);
+			td->status = 0;
+		}
+
+
+		if (td)
+			td->bufptr = req->req.dma + i; /* assign buffer */
+		else
+			break;
+
+		/* short packet ? */
+		if ((bytes - i) >= buf_len) {
+			txbytes = buf_len;
+		} else {
+			/* short packet */
+			txbytes = bytes - i;
+		}
+
+		/* link td and assign tx bytes */
+		if (i == buf_len) {
+			if (create_new_chain) {
+				req->td_data->next = dma_addr;
+			} else {
+				/* req->td_data->next = virt_to_phys(td); */
+			}
+			/* write tx bytes */
+			if (ep->in) {
+				/* first desc */
+				req->td_data->status =
+					AMD_ADDBITS(req->td_data->status,
+							ep->ep.maxpacket,
+							UDC_DMA_IN_STS_TXBYTES);
+				/* second desc */
+				td->status = AMD_ADDBITS(td->status,
+							txbytes,
+							UDC_DMA_IN_STS_TXBYTES);
+			}
+		} else {
+			if (create_new_chain) {
+				last->next = dma_addr;
+			} else {
+				/* last->next = virt_to_phys(td); */
+			}
+			if (ep->in) {
+				/* write