usb: gadget: bcm63xx UDC driver

Driver for the "USB20D" / "USBD" block on BCM6328, BCM6368, BCM6816,
BCM6362, BCM3383, and others.

The hardware block was designed to support networking applications
(direct connection of a home router to a PC), and the endpoint
configuration is fixed.

[ balbi@ti.com : dropped USB_GADGET_DUALSPEED from Kconfig ]

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Acked-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Signed-off-by: Felipe Balbi <balbi@ti.com>

1 files changed, 2464 insertions, 0 deletions

diff --git a/drivers/usb/gadget/bcm63xx_udc.c b/drivers/usb/gadget/bcm63xx_udc.c
new file mode 100644
index 000000000000..9ca792224cd4
--- /dev/null
+++ b/drivers/usb/gadget/bcm63xx_udc.c
@@ -0,0 +1,2464 @@
+/*
+ * bcm63xx_udc.c -- BCM63xx UDC high/full speed USB device controller
+ *
+ * Copyright (C) 2012 Kevin Cernekee <cernekee@gmail.com>
+ * Copyright (C) 2012 Broadcom Corporation
+ *
+ * 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.
+ */
+
+#include <linux/bitops.h>
+#include <linux/bug.h>
+#include <linux/clk.h>
+#include <linux/compiler.h>
+#include <linux/debugfs.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/ioport.h>
+#include <linux/kconfig.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/platform_device.h>
+#include <linux/sched.h>
+#include <linux/seq_file.h>
+#include <linux/slab.h>
+#include <linux/timer.h>
+#include <linux/usb/ch9.h>
+#include <linux/usb/gadget.h>
+#include <linux/workqueue.h>
+
+#include <bcm63xx_cpu.h>
+#include <bcm63xx_iudma.h>
+#include <bcm63xx_dev_usb_usbd.h>
+#include <bcm63xx_io.h>
+#include <bcm63xx_regs.h>
+
+#define DRV_MODULE_NAME		"bcm63xx_udc"
+
+static const char bcm63xx_ep0name[] = "ep0";
+static const char *const bcm63xx_ep_name[] = {
+	bcm63xx_ep0name,
+	"ep1in-bulk", "ep2out-bulk", "ep3in-int", "ep4out-int",
+};
+
+static bool use_fullspeed;
+module_param(use_fullspeed, bool, S_IRUGO);
+MODULE_PARM_DESC(use_fullspeed, "true for fullspeed only");
+
+/*
+ * RX IRQ coalescing options:
+ *
+ * false (default) - one IRQ per DATAx packet.  Slow but reliable.  The
+ * driver is able to pass the "testusb" suite and recover from conditions like:
+ *
+ *   1) Device queues up a 2048-byte RX IUDMA transaction on an OUT bulk ep
+ *   2) Host sends 512 bytes of data
+ *   3) Host decides to reconfigure the device and sends SET_INTERFACE
+ *   4) Device shuts down the endpoint and cancels the RX transaction
+ *
+ * true - one IRQ per transfer, for transfers <= 2048B.  Generates
+ * considerably fewer IRQs, but error recovery is less robust.  Does not
+ * reliably pass "testusb".
+ *
+ * TX always uses coalescing, because we can cancel partially complete TX
+ * transfers by repeatedly flushing the FIFO.  The hardware doesn't allow
+ * this on RX.
+ */
+static bool irq_coalesce;
+module_param(irq_coalesce, bool, S_IRUGO);
+MODULE_PARM_DESC(irq_coalesce, "take one IRQ per RX transfer");
+
+#define BCM63XX_NUM_EP			5
+#define BCM63XX_NUM_IUDMA		6
+#define BCM63XX_NUM_FIFO_PAIRS		3
+
+#define IUDMA_RESET_TIMEOUT_US		10000
+
+#define IUDMA_EP0_RXCHAN		0
+#define IUDMA_EP0_TXCHAN		1
+
+#define IUDMA_MAX_FRAGMENT		2048
+#define BCM63XX_MAX_CTRL_PKT		64
+
+#define BCMEP_CTRL			0x00
+#define BCMEP_ISOC			0x01
+#define BCMEP_BULK			0x02
+#define BCMEP_INTR			0x03
+
+#define BCMEP_OUT			0x00
+#define BCMEP_IN			0x01
+
+#define BCM63XX_SPD_FULL		1
+#define BCM63XX_SPD_HIGH		0
+
+#define IUDMA_DMAC_OFFSET		0x200
+#define IUDMA_DMAS_OFFSET		0x400
+
+enum bcm63xx_ep0_state {
+	EP0_REQUEUE,
+	EP0_IDLE,
+	EP0_IN_DATA_PHASE_SETUP,
+	EP0_IN_DATA_PHASE_COMPLETE,
+	EP0_OUT_DATA_PHASE_SETUP,
+	EP0_OUT_DATA_PHASE_COMPLETE,
+	EP0_OUT_STATUS_PHASE,
+	EP0_IN_FAKE_STATUS_PHASE,
+	EP0_SHUTDOWN,
+};
+
+static const char __maybe_unused bcm63xx_ep0_state_names[][32] = {
+	"REQUEUE",
+	"IDLE",
+	"IN_DATA_PHASE_SETUP",
+	"IN_DATA_PHASE_COMPLETE",
+	"OUT_DATA_PHASE_SETUP",
+	"OUT_DATA_PHASE_COMPLETE",
+	"OUT_STATUS_PHASE",
+	"IN_FAKE_STATUS_PHASE",
+	"SHUTDOWN",
+};
+
+/**
+ * struct iudma_ch_cfg - Static configuration for an IUDMA channel.
+ * @ep_num: USB endpoint number.
+ * @n_bds: Number of buffer descriptors in the ring.
+ * @ep_type: Endpoint type (control, bulk, interrupt).
+ * @dir: Direction (in, out).
+ * @n_fifo_slots: Number of FIFO entries to allocate for this channel.
+ * @max_pkt_hs: Maximum packet size in high speed mode.
+ * @max_pkt_fs: Maximum packet size in full speed mode.
+ */
+struct iudma_ch_cfg {
+	int				ep_num;
+	int				n_bds;
+	int				ep_type;
+	int				dir;
+	int				n_fifo_slots;
+	int				max_pkt_hs;
+	int				max_pkt_fs;
+};
+
+static const struct iudma_ch_cfg iudma_defaults[] = {
+
+	/* This controller was designed to support a CDC/RNDIS application.
+	   It may be possible to reconfigure some of the endpoints, but
+	   the hardware limitations (FIFO sizing and number of DMA channels)
+	   may significantly impact flexibility and/or stability.  Change
+	   these values at your own risk.
+
+	      ep_num       ep_type           n_fifo_slots    max_pkt_fs
+	idx      |  n_bds     |         dir       |  max_pkt_hs  |
+	 |       |    |       |          |        |      |       |       */
+	[0] = { -1,   4, BCMEP_CTRL, BCMEP_OUT,  32,    64,     64 },
+	[1] = {  0,   4, BCMEP_CTRL, BCMEP_OUT,  32,    64,     64 },
+	[2] = {  2,  16, BCMEP_BULK, BCMEP_OUT, 128,   512,     64 },
+	[3] = {  1,  16, BCMEP_BULK, BCMEP_IN,  128,   512,     64 },
+	[4] = {  4,   4, BCMEP_INTR, BCMEP_OUT,  32,    64,     64 },
+	[5] = {  3,   4, BCMEP_INTR, BCMEP_IN,   32,    64,     64 },
+};
+
+struct bcm63xx_udc;
+
+/**
+ * struct iudma_ch - Represents the current state of a single IUDMA channel.
+ * @ch_idx: IUDMA channel index (0 to BCM63XX_NUM_IUDMA-1).
+ * @ep_num: USB endpoint number.  -1 for ep0 RX.
+ * @enabled: Whether bcm63xx_ep_enable() has been called.
+ * @max_pkt: "Chunk size" on the USB interface.  Based on interface speed.
+ * @is_tx: true for TX, false for RX.
+ * @bep: Pointer to the associated endpoint.  NULL for ep0 RX.
+ * @udc: Reference to the device controller.
+ * @read_bd: Next buffer descriptor to reap from the hardware.
+ * @write_bd: Next BD available for a new packet.
+ * @end_bd: Points to the final BD in the ring.
+ * @n_bds_used: Number of BD entries currently occupied.
+ * @bd_ring: Base pointer to the BD ring.
+ * @bd_ring_dma: Physical (DMA) address of bd_ring.
+ * @n_bds: Total number of BDs in the ring.
+ *
+ * ep0 has two IUDMA channels (IUDMA_EP0_RXCHAN and IUDMA_EP0_TXCHAN), as it is
+ * bidirectional.  The "struct usb_ep" associated with ep0 is for TX (IN)
+ * only.
+ *
+ * Each bulk/intr endpoint has a single IUDMA channel and a single
+ * struct usb_ep.
+ */
+struct iudma_ch {
+	unsigned int			ch_idx;
+	int				ep_num;
+	bool				enabled;
+	int				max_pkt;
+	bool				is_tx;
+	struct bcm63xx_ep		*bep;
+	struct bcm63xx_udc		*udc;
+
+	struct bcm_enet_desc		*read_bd;
+	struct bcm_enet_desc		*write_bd;
+	struct bcm_enet_desc		*end_bd;
+	int				n_bds_used;
+
+	struct bcm_enet_desc		*bd_ring;
+	dma_addr_t			bd_ring_dma;
+	unsigned int			n_bds;
+};
+
+/**
+ * struct bcm63xx_ep - Internal (driver) state of a single endpoint.
+ * @ep_num: USB endpoint number.
+ * @iudma: Pointer to IUDMA channel state.
+ * @ep: USB gadget layer representation of the EP.
+ * @udc: Reference to the device controller.
+ * @queue: Linked list of outstanding requests for this EP.
+ * @halted: 1 if the EP is stalled; 0 otherwise.
+ */
+struct bcm63xx_ep {
+	unsigned int			ep_num;
+	struct iudma_ch			*iudma;
+	struct usb_ep			ep;
+	struct bcm63xx_udc		*udc;
+	struct list_head		queue;
+	unsigned			halted:1;
+};
+
+/**
+ * struct bcm63xx_req - Internal (driver) state of a single request.
+ * @queue: Links back to the EP's request list.
+ * @req: USB gadget layer representation of the request.
+ * @offset: Current byte offset into the data buffer (next byte to queue).
+ * @bd_bytes: Number of data bytes in outstanding BD entries.
+ * @iudma: IUDMA channel used for the request.
+ */
+struct bcm63xx_req {
+	struct list_head		queue;		/* ep's requests */
+	struct usb_request		req;
+	unsigned int			offset;
+	unsigned int			bd_bytes;
+	struct iudma_ch			*iudma;
+};
+
+/**
+ * struct bcm63xx_udc - Driver/hardware private context.
+ * @lock: Spinlock to mediate access to this struct, and (most) HW regs.
+ * @dev: Generic Linux device structure.
+ * @pd: Platform data (board/port info).
+ * @usbd_clk: Clock descriptor for the USB device block.
+ * @usbh_clk: Clock descriptor for the USB host block.
+ * @gadget: USB slave device.
+ * @driver: Driver for USB slave devices.
+ * @usbd_regs: Base address of the USBD/USB20D block.
+ * @iudma_regs: Base address of the USBD's associated IUDMA block.
+ * @bep: Array of endpoints, including ep0.
+ * @iudma: Array of all IUDMA channels used by this controller.
+ * @cfg: USB configuration number, from SET_CONFIGURATION wValue.
+ * @iface: USB interface number, from SET_INTERFACE wIndex.
+ * @alt_iface: USB alt interface number, from SET_INTERFACE wValue.
+ * @ep0_ctrl_req: Request object for bcm63xx_udc-initiated ep0 transactions.
+ * @ep0_ctrl_buf: Data buffer for ep0_ctrl_req.
+ * @ep0state: Current state of the ep0 state machine.
+ * @ep0_wq: Workqueue struct used to wake up the ep0 state machine.
+ * @wedgemap: Bitmap of wedged endpoints.
+ * @ep0_req_reset: USB reset is pending.
+ * @ep0_req_set_cfg: Need to spoof a SET_CONFIGURATION packet.
+ * @ep0_req_set_iface: Need to spoof a SET_INTERFACE packet.
+ * @ep0_req_shutdown: Driver is shutting down; requesting ep0 to halt activity.
+ * @ep0_req_completed: ep0 request has completed; worker has not seen it yet.
+ * @ep0_reply: Pending reply from gadget driver.
+ * @ep0_request: Outstanding ep0 request.
+ * @debugfs_root: debugfs directory: /sys/kernel/debug/<DRV_MODULE_NAME>.
+ * @debugfs_usbd: debugfs file "usbd" for controller state.
+ * @debugfs_iudma: debugfs file "usbd" for IUDMA state.
+ */
+struct bcm63xx_udc {
+	spinlock_t			lock;
+
+	struct device			*dev;
+	struct bcm63xx_usbd_platform_data *pd;
+	struct clk			*usbd_clk;
+	struct clk			*usbh_clk;
+
+	struct usb_gadget		gadget;
+	struct usb_gadget_driver	*driver;
+
+	void __iomem			*usbd_regs;
+	void __iomem			*iudma_regs;
+
+	struct bcm63xx_ep		bep[BCM63XX_NUM_EP];
+	struct iudma_ch			iudma[BCM63XX_NUM_IUDMA];
+
+	int				cfg;
+	int				iface;
+	int				alt_iface;
+
+	struct bcm63xx_req		ep0_ctrl_req;
+	u8				*ep0_ctrl_buf;
+
+	int				ep0state;
+	struct work_struct		ep0_wq;
+
+	unsigned long			wedgemap;
+
+	unsigned			ep0_req_reset:1;
+	unsigned			ep0_req_set_cfg:1;
+	unsigned			ep0_req_set_iface:1;
+	unsigned			ep0_req_shutdown:1;
+
+	unsigned			ep0_req_completed:1;
+	struct usb_request		*ep0_reply;
+	struct usb_request		*ep0_request;
+
+	struct dentry			*debugfs_root;
+	struct dentry			*debugfs_usbd;
+	struct dentry			*debugfs_iudma;
+};
+
+static const struct usb_ep_ops bcm63xx_udc_ep_ops;
+
+/***********************************************************************
+ * Convenience functions
+ ***********************************************************************/
+
+static inline struct bcm63xx_udc *gadget_to_udc(struct usb_gadget *g)
+{
+	return container_of(g, struct bcm63xx_udc, gadget);
+}
+
+static inline struct bcm63xx_ep *our_ep(struct usb_ep *ep)
+{
+	return container_of(ep, struct bcm63xx_ep, ep);
+}
+
+static inline struct bcm63xx_req *our_req(struct usb_request *req)
+{
+	return container_of(req, struct bcm63xx_req, req);
+}
+
+static inline u32 usbd_readl(struct bcm63xx_udc *udc, u32 off)
+{
+	return bcm_readl(udc->usbd_regs + off);
+}
+
+static inline void usbd_writel(struct bcm63xx_udc *udc, u32 val, u32 off)
+{
+	bcm_writel(val, udc->usbd_regs + off);
+}
+
+static inline u32 usb_dma_readl(struct bcm63xx_udc *udc, u32 off)
+{
+	return bcm_readl(udc->iudma_regs + off);
+}
+
+static inline void usb_dma_writel(struct bcm63xx_udc *udc, u32 val, u32 off)
+{
+	bcm_writel(val, udc->iudma_regs + off);
+}
+
+static inline u32 usb_dmac_readl(struct bcm63xx_udc *udc, u32 off)
+{
+	return bcm_readl(udc->iudma_regs + IUDMA_DMAC_OFFSET + off);
+}
+
+static inline void usb_dmac_writel(struct bcm63xx_udc *udc, u32 val, u32 off)
+{
+	bcm_writel(val, udc->iudma_regs + IUDMA_DMAC_OFFSET + off);
+}
+
+static inline u32 usb_dmas_readl(struct bcm63xx_udc *udc, u32 off)
+{
+	return bcm_readl(udc->iudma_regs + IUDMA_DMAS_OFFSET + off);
+}
+
+static inline void usb_dmas_writel(struct bcm63xx_udc *udc, u32 val, u32 off)
+{
+	bcm_writel(val, udc->iudma_regs + IUDMA_DMAS_OFFSET + off);
+}
+
+static inline void set_clocks(struct bcm63xx_udc *udc, bool is_enabled)
+{
+	if (is_enabled) {
+		clk_enable(udc->usbh_clk);
+		clk_enable(udc->usbd_clk);
+		udelay(10);
+	} else {
+		clk_disable(udc->usbd_clk);
+		clk_disable(udc->usbh_clk);
+	}
+}
+
+/***********************************************************************
+ * Low-level IUDMA / FIFO operations
+ ***********************************************************************/
+
+/**
+ * bcm63xx_ep_dma_select - Helper function to set up the init_sel signal.
+ * @udc: Reference to the device controller.
+ * @idx: Desired init_sel value.
+ *
+ * The "init_sel" signal is used as a selection index for both endpoints
+ * and IUDMA channels.  Since these do not map 1:1, the use of this signal
+ * depends on the context.
+ */
+static void bcm63xx_ep_dma_select(struct bcm63xx_udc *udc, int idx)
+{
+	u32 val = usbd_readl(udc, USBD_CONTROL_REG);
+
+	val &= ~USBD_CONTROL_INIT_SEL_MASK;
+	val |= idx << USBD_CONTROL_INIT_SEL_SHIFT;
+	usbd_writel(udc, val, USBD_CONTROL_REG);
+}
+
+/**
+ * bcm63xx_set_stall - Enable/disable stall on one endpoint.
+ * @udc: Reference to the device controller.
+ * @bep: Endpoint on which to operate.
+ * @is_stalled: true to enable stall, false to disable.
+ *
+ * See notes in bcm63xx_update_wedge() regarding automatic clearing of
+ * halt/stall conditions.
+ */
+static void bcm63xx_set_stall(struct bcm63xx_udc *udc, struct bcm63xx_ep *bep,
+	bool is_stalled)
+{
+	u32 val;
+
+	val = USBD_STALL_UPDATE_MASK |
+		(is_stalled ? USBD_STALL_ENABLE_MASK : 0) |
+		(bep->ep_num << USBD_STALL_EPNUM_SHIFT);
+	usbd_writel(udc, val, USBD_STALL_REG);
+}
+
+/**
+ * bcm63xx_fifo_setup - (Re)initialize FIFO boundaries and settings.
+ * @udc: Reference to the device controller.
+ *
+ * These parameters depend on the USB link speed.  Settings are
+ * per-IUDMA-channel-pair.
+ */
+static void bcm63xx_fifo_setup(struct bcm63xx_udc *udc)
+{
+	int is_hs = udc->gadget.speed == USB_SPEED_HIGH;
+	u32 i, val, rx_fifo_slot, tx_fifo_slot;
+
+	/* set up FIFO boundaries and packet sizes; this is done in pairs */
+	rx_fifo_slot = tx_fifo_slot = 0;
+	for (i = 0; i < BCM63XX_NUM_IUDMA; i += 2) {
+		const struct iudma_ch_cfg *rx_cfg = &iudma_defaults[i];
+		const struct iudma_ch_cfg *tx_cfg = &iudma_defaults[i + 1];
+
+		bcm63xx_ep_dma_select(udc, i >> 1);
+
+		val = (rx_fifo_slot << USBD_RXFIFO_CONFIG_START_SHIFT) |
+			((rx_fifo_slot + rx_cfg->n_fifo_slots - 1) <<
+			 USBD_RXFIFO_CONFIG_END_SHIFT);
+		rx_fifo_slot += rx_cfg->n_fifo_slots;
+		usbd_writel(udc, val, USBD_RXFIFO_CONFIG_REG);
+		usbd_writel(udc,
+			    is_hs ? rx_cfg->max_pkt_hs : rx_cfg->max_pkt_fs,
+			    USBD_RXFIFO_EPSIZE_REG);
+
+		val = (tx_fifo_slot << USBD_TXFIFO_CONFIG_START_SHIFT) |
+			((tx_fifo_slot + tx_cfg->n_fifo_slots - 1) <<
+			 USBD_TXFIFO_CONFIG_END_SHIFT);
+		tx_fifo_slot += tx_cfg->n_fifo_slots;
+		usbd_writel(udc, val, USBD_TXFIFO_CONFIG_REG);
+		usbd_writel(udc,
+			    is_hs ? tx_cfg->max_pkt_hs : tx_cfg->max_pkt_fs,
+			    USBD_TXFIFO_EPSIZE_REG);
+
+		usbd_readl(udc, USBD_TXFIFO_EPSIZE_REG);
+	}
+}
+
+/**
+ * bcm63xx_fifo_reset_ep - Flush a single endpoint's FIFO.
+ * @udc: Reference to the device controller.
+ * @ep_num: Endpoint number.
+ */
+static void bcm63xx_fifo_reset_ep(struct bcm63xx_udc *udc, int ep_num)
+{
+	u32 val;
+
+	bcm63xx_ep_dma_select(udc, ep_num);
+
+	val = usbd_readl(udc, USBD_CONTROL_REG);
+	val |= USBD_CONTROL_FIFO_RESET_MASK;
+	usbd_writel(udc, val, USBD_CONTROL_REG);
+	usbd_readl(udc, USBD_CONTROL_REG);
+}
+
+/**
+ * bcm63xx_fifo_reset - Flush all hardware FIFOs.
+ * @udc: Reference to the device controller.
+ */
+static void bcm63xx_fifo_reset(struct bcm63xx_udc *udc)
+{
+	int i;
+
+	for (i = 0; i < BCM63XX_NUM_FIFO_PAIRS; i++)
+		bcm63xx_fifo_reset_ep(udc, i);
+}
+
+/**
+ * bcm63xx_ep_init - Initial (one-time) endpoint initialization.
+ * @udc: Reference to the device controller.
+ */
+static void bcm63xx_ep_init(struct bcm63xx_udc *udc)
+{
+	u32 i, val;
+
+	for (i = 0; i < BCM63XX_NUM_IUDMA; i++) {
+		const struct iudma_ch_cfg *cfg = &iudma_defaults[i];
+
+		if (cfg->ep_num < 0)
+			continue;
+
+		bcm63xx_ep_dma_select(udc, cfg->ep_num);
+		val = (cfg->ep_type << USBD_EPNUM_TYPEMAP_TYPE_SHIFT) |
+			((i >> 1) << USBD_EPNUM_TYPEMAP_DMA_CH_SHIFT);
+		usbd_writel(udc, val, USBD_EPNUM_TYPEMAP_REG);
+	}
+}
+
+/**
+ * bcm63xx_ep_setup - Configure per-endpoint settings.
+ * @udc: Reference to the device controller.
+ *
+ * This needs to be rerun if the speed/cfg/intf/altintf changes.
+ */
+static void bcm63xx_ep_setup(struct bcm63xx_udc *udc)
+{
+	u32 val, i;
+
+	usbd_writel(udc, USBD_CSR_SETUPADDR_DEF, USBD_CSR_SETUPADDR_REG);
+
+	for (i = 0; i < BCM63XX_NUM_IUDMA; i++) {
+		const struct iudma_ch_cfg *cfg = &iudma_defaults[i];
+		int max_pkt = udc->gadget.speed == USB_SPEED_HIGH ?
+			      cfg->max_pkt_hs : cfg->max_pkt_fs;
+		int idx = cfg->ep_num;
+
+		udc->iudma[i].max_pkt = max_pkt;
+
+		if (idx < 0)
+			continue;
+		udc->bep[idx].ep.maxpacket = max_pkt;
+
+		val = (idx << USBD_CSR_EP_LOG_SHIFT) |
+		      (cfg->dir << USBD_CSR_EP_DIR_SHIFT) |
+		      (cfg->ep_type << USBD_CSR_EP_TYPE_SHIFT) |
+		      (udc->cfg << USBD_CSR_EP_CFG_SHIFT) |
+		      (udc->iface << USBD_CSR_EP_IFACE_SHIFT) |
+		      (udc->alt_iface << USBD_CSR_EP_ALTIFACE_SHIFT) |
+		      (max_pkt << USBD_CSR_EP_MAXPKT_SHIFT);
+		usbd_writel(udc, val, USBD_CSR_EP_REG(idx));
+	}
+}
+
+/**
+ * iudma_write - Queue a single IUDMA transaction.
+ * @udc: Reference to the device controller.
+ * @iudma: IUDMA channel to use.
+ * @breq: Request containing the transaction data.
+ *
+ * For RX IUDMA, this will queue a single buffer descriptor, as RX IUDMA
+ * does not honor SOP/EOP so the handling of multiple buffers is ambiguous.
+ * So iudma_write() may be called several times to fulfill a single
+ * usb_request.
+ *
+ * For TX IUDMA, this can queue multiple buffer descriptors if needed.
+ */
+static void iudma_write(struct bcm63xx_udc *udc, struct iudma_ch *iudma,
+	struct bcm63xx_req *breq)
+{
+	int first_bd = 1, last_bd = 0, extra_zero_pkt = 0;
+	unsigned int bytes_left = breq->req.length - breq->offset;
+	const int max_bd_bytes = !irq_coalesce && !iudma->is_tx ?
+		iudma->max_pkt : IUDMA_MAX_FRAGMENT;
+
+	iudma->n_bds_used = 0;
+	breq->bd_bytes = 0;
+	breq->iudma = iudma;
+
+	if ((bytes_left % iudma->max_pkt == 0) && bytes_left && breq->req.zero)
+		extra_zero_pkt = 1;
+
+	do {
+		struct bcm_enet_desc *d = iudma->write_bd;
+		u32 dmaflags = 0;
+		unsigned int n_bytes;
+
+		if (d == iudma->end_bd) {
+			dmaflags |= DMADESC_WRAP_MASK;
+			iudma->write_bd = iudma->bd_ring;
+		} else {
+			iudma->write_bd++;
+		}
+		iudma->n_bds_used++;
+
+		n_bytes = min_t(int, bytes_left, max_bd_bytes);
+		if (n_bytes)
+			dmaflags |= n_bytes << DMADESC_LENGTH_SHIFT;
+		else
+			dmaflags |= (1 << DMADESC_LENGTH_SHIFT) |
+				    DMADESC_USB_ZERO_MASK;
+
+		dmaflags |= DMADESC_OWNER_MASK;
+		if (first_bd) {
+			dmaflags |= DMADESC_SOP_MASK;
+			first_bd = 0;
+		}
+
+		/*
+		 * extra_zero_pkt forces one more iteration through the loop
+		 * after all data is queued up, to send the zero packet
+		 */
+		if (extra_zero_pkt && !bytes_left)
+			extra_zero_pkt = 0;
+
+		if (!iudma->is_tx || iudma->n_bds_used == iudma->n_bds ||
+		    (n_bytes == bytes_left && !extra_zero_pkt)) {
+			last_bd = 1;
+			dmaflags |= DMADESC_EOP_MASK;
+		}
+
+		d->address = breq->req.dma + breq->offset;
+		mb();
+		d->len_stat = dmaflags;
+
+		breq->offset += n_bytes;
+		breq->bd_bytes += n_bytes;
+		bytes_left -= n_bytes;
+	} while (!last_bd);
+
+	usb_dmac_writel(udc, ENETDMAC_CHANCFG_EN_MASK,
+			ENETDMAC_CHANCFG_REG(iudma->ch_idx));
+}
+
+/**
+ * iudma_read - Check for IUDMA buffer completion.
+ * @udc: Reference to the device controller.
+ * @iudma: IUDMA channel to use.
+ *
+ * This checks to see if ALL of the outstanding BDs on the DMA channel
+ * have been filled.  If so, it returns the actual transfer length;
+ * otherwise it returns -EBUSY.
+ */
+static int iudma_read(struct bcm63xx_udc *udc, struct iudma_ch *iudma)
+{
+	int i, actual_len = 0;
+	struct bcm_enet_desc *d = iudma->read_bd;
+
+	if (!iudma->n_bds_used)
+		return -EINVAL;
+
+	for (i = 0; i < iudma->n_bds_used; i++) {
+		u32 dmaflags;
+
+		dmaflags = d->len_stat;
+
+		if (dmaflags & DMADESC_OWNER_MASK)
+			return -EBUSY;
+
+		actual_len += (dmaflags & DMADESC_LENGTH_MASK) >>
+			      DMADESC_LENGTH_SHIFT;
+		if (d == iudma->end_bd)
+			d = iudma->bd_ring;
+		else
+			d++;
+	}
+
+	iudma->read_bd = d;
+	iudma->n_bds_used = 0;
+	return actual_len;
+}
+
+/**
+ * iudma_reset_channel - Stop DMA on a single channel.
+ * @udc: Reference to the device controller.
+ * @iudma: IUDMA channel to reset.
+ */
+static void iudma_reset_channel(struct bcm63xx_udc *udc, struct iudma_ch *iudma)
+{
+	int timeout = IUDMA_RESET_TIMEOUT_US;
+	struct bcm_enet_desc *d;
+	int ch_idx = iudma->ch_idx;
+
+	if (!iudma->is_tx)
+		bcm63xx_fifo_reset_ep(udc, max(0, iudma->ep_num));
+
+	/* stop DMA, then wait for the hardware to wrap up */
+	usb_dmac_writel(udc, 0, ENETDMAC_CHANCFG_REG(ch_idx));
+
+	while (usb_dmac_readl(udc, ENETDMAC_CHANCFG_REG(ch_idx)) &
+				   ENETDMAC_CHANCFG_EN_MASK) {
+		udelay(1);
+
+		/* repeatedly flush the FIFO data until the BD completes */
+		if (iudma->is_tx && iudma->ep_num >= 0)
+			bcm63xx_fifo_reset_ep(udc, iudma->ep_num);
+
+		if (!timeout--) {
+			dev_err(udc->dev, "can't reset IUDMA channel %d\n",
+				ch_idx);
+			break;
+		}
+		if (timeout == IUDMA_RESET_TIMEOUT_US / 2) {
+			dev_warn(udc->dev, "forcibly halting IUDMA channel %d\n",
+				 ch_idx);
+			usb_dmac_writel(udc, ENETDMAC_CHANCFG_BUFHALT_MASK,
+					ENETDMAC_CHANCFG_REG(ch_idx));
+		}
+	}
+	usb_dmac_writel(udc, ~0, ENETDMAC_IR_REG(ch_idx));
+
+	/* don't leave "live" HW-owned entries for the next guy to step on */
+	for (d = iudma->bd_ring; d <= iudma->end_bd; d++)
+		d->len_stat = 0;
+	mb();
+
+	iudma->read_bd = iudma->write_bd = iudma->bd_ring;
+	iudma->n_bds_used = 0;
+
+	/* set up IRQs, UBUS burst size, and BD base for this channel */
+	usb_dmac_writel(udc, ENETDMAC_IR_BUFDONE_MASK,
+			ENETDMAC_IRMASK_REG(ch_idx));
+	usb_dmac_writel(udc, 8, ENETDMAC_MAXBURST_REG(ch_idx));
+
+	usb_dmas_writel(udc, iudma->bd_ring_dma, ENETDMAS_RSTART_REG(ch_idx));
+	usb_dmas_writel(udc, 0, ENETDMAS_SRAM2_REG(ch_idx));
+}
+
+/**
+ * iudma_init_channel - One-time IUDMA channel initialization.
+ * @udc: Reference to the device controller.
+ * @ch_idx: Channel to initialize.
+ */
+static int iudma_init_channel(struct bcm63xx_udc *udc, unsigned int ch_idx)
+{
+	struct iudma_ch *iudma = &udc->iudma[ch_idx];
+	const struct iudma_ch_cfg *cfg = &iudma_defaults[ch_idx];
+	unsigned int n_bds = cfg->n_bds;
+	struct bcm63xx_ep *bep = NULL;
+
+	iudma->ep_num = cfg->ep_num;
+	iudma->ch_idx = ch_idx;
+	iudma->is_tx = !!(ch_idx & 0x01);
+	if (iudma->ep_num >= 0) {
+		bep = &udc->bep[iudma->ep_num];
+		bep->iudma = iudma;
+		INIT_LIST_HEAD(&bep->queue);
+	}
+
+	iudma->bep = bep;
+	iudma->udc = udc;
+
+	/* ep0 is always active; others are controlled by the gadget driver */
+	if (iudma->ep_num <= 0)
+		iudma->enabled = true;
+
+	iudma->n_bds = n_bds;
+	iudma->bd_ring = dmam_alloc_coherent(udc->dev,
+		n_bds * sizeof(struct bcm_enet_desc),
+		&iudma->bd_ring_dma, GFP_KERNEL);
+	if (!iudma->bd_ring)
+		return -ENOMEM;
+	iudma->end_bd = &iudma->bd_ring[n_bds - 1];
+
+	return 0;
+}
+
+/**
+ * iudma_init - One-time initialization of all IUDMA channels.
+ * @udc: Reference to the device controller.
+ *
+ * Enable DMA, flush channels, and enable global IUDMA IRQs.
+ */
+static int iudma_init(struct bcm63xx_udc *udc)
+{
+	int i, rc;
+
+	usb_dma_writel(udc, ENETDMA_CFG_EN_MASK, ENETDMA_CFG_REG);
+
+	for (i = 0; i < BCM63XX_NUM_IUDMA; i++) {
+		rc = iudma_init_channel(udc, i);
+		if (rc)
+			return rc;
+		iudma_reset_channel(udc, &udc->iudma[i]);
+	}
+
+	usb_dma_writel(udc, BIT(BCM63XX_NUM_IUDMA)-1, ENETDMA_GLB_IRQMASK_REG);
+	return 0;
+}
+
+/**
+ * iudma_uninit - Uninitialize IUDMA channels.
+ * @udc: Reference to the device controller.
+ *
+ * Kill global IUDMA IRQs, flush channels, and kill DMA.
+ */
+static void iudma_uninit(struct bcm63xx_udc *udc)
+{
+	int i;
+
+	usb_dma_writel(udc, 0, ENETDMA_GLB_IRQMASK_REG);
+
+	for (i = 0; i < BCM63XX_NUM_IUDMA; i++)
+		iudma_reset_channel(udc, &udc->iudma[i]);
+
+	usb_dma_writel(udc, 0, ENETDMA_CFG_REG);
+}
+
+/***********************************************************************
+ * Other low-level USBD operations
+ ***********************************************************************/
+
+/**
+ * bcm63xx_set_ctrl_irqs - Mask/unmask control path interrupts.
+ * @udc: Reference to the device controller.
+ * @enable_irqs: true to enable, false to disable.
+ */
+static void bcm63xx_set_ctrl_irqs(struct bcm63xx_udc *udc, bool enable_irqs)
+{
+	u32 val;
+
+	usbd_writel(udc, 0, USBD_STATUS_REG);
+
+	val = BIT(USBD_EVENT_IRQ_USB_RESET) |
+	      BIT(USBD_EVENT_IRQ_SETUP) |
+	      BIT(USBD_EVENT_IRQ_SETCFG) |
+	      BIT(USBD_EVENT_IRQ_SETINTF) |
+	      BIT(USBD_EVENT_IRQ_USB_LINK);
+	usbd_writel(udc, enable_irqs ? val : 0, USBD_EVENT_IRQ_MASK_REG);
+	usbd_writel(udc, val, USBD_EVENT_IRQ_STATUS_REG);
+}
+
+/**
+ * bcm63xx_select_phy_mode - Select between USB device and host mode.
+ * @udc: Reference to the device controller.
+ * @is_device: true for device, false for host.
+ *
+ * This should probably be reworked to use the drivers/usb/otg
+ * infrastructure.
+ *
+ * By default, the AFE/pullups are disabled in device mode, until
+ * bcm63xx_select_pullup() is called.
+ */
+static void bcm63xx_select_phy_mode(struct bcm63xx_udc *udc, bool is_device)
+{
+	u32 val, portmask = BIT(udc->pd->port_no);
+
+	if (BCMCPU_IS_6328()) {
+		/* configure pinmux to sense VBUS signal */
+		val = bcm_gpio_readl(GPIO_PINMUX_OTHR_REG);
+		val &= ~GPIO_PINMUX_OTHR_6328_USB_MASK;
+		val |= is_device ? GPIO_PINMUX_OTHR_6328_USB_DEV :
+			       GPIO_PINMUX_OTHR_6328_USB_HOST;
+		bcm_gpio_writel(val, GPIO_PINMUX_OTHR_REG);
+	}
+
+	val = bcm_rset_readl(RSET_USBH_PRIV, USBH_PRIV_UTMI_CTL_6368_REG);
+	if (is_device) {
+		val |= (portmask << USBH_PRIV_UTMI_CTL_HOSTB_SHIFT);
+		val |= (portmask << USBH_PRIV_UTMI_CTL_NODRIV_SHIFT);
+	} else {
+		val &= ~(portmask << USBH_PRIV_UTMI_CTL_HOSTB_SHIFT);
+		val &= ~(portmask << USBH_PRIV_UTMI_CTL_NODRIV_SHIFT);
+	}
+	bcm_rset_writel(RSET_USBH_PRIV, val, USBH_PRIV_UTMI_CTL_6368_REG);
+
+	val = bcm_rset_readl(RSET_USBH_PRIV, USBH_PRIV_SWAP_6368_REG);
+	if (is_device)
+		val |= USBH_PRIV_SWAP_USBD_MASK;
+	else
+		val &= ~USBH_PRIV_SWAP_USBD_MASK;
+	bcm_rset_writel(RSET_USBH_PRIV, val, USBH_PRIV_SWAP_6368_REG);
+}
+
+/**
+ * bcm63xx_select_pullup - Enable/disable the pullup on D+
+ * @udc: Reference to the device controller.
+ * @is_on: true to enable the pullup, false to disable.
+ *
+ * If the pullup is active, the host will sense a FS/HS device connected to
+ * the port.  If the pullup is inactive, the host will think the USB
+ * device has been disconnected.
+ */
+static void bcm63xx_select_pullup(struct bcm63xx_udc *udc, bool is_on)
+{
+	u32 val, portmask = BIT(udc->pd->port_no);
+
+	val = bcm_rset_readl(RSET_USBH_PRIV, USBH_PRIV_UTMI_CTL_6368_REG);
+	if (is_on)
+		val &= ~(portmask << USBH_PRIV_UTMI_CTL_NODRIV_SHIFT);
+	else
+		val |= (portmask << USBH_PRIV_UTMI_CTL_NODRIV_SHIFT);
+	bcm_rset_writel(RSET_USBH_PRIV, val, USBH_PRIV_UTMI_CTL_6368_REG);
+}
+
+/**
+ * bcm63xx_uninit_udc_hw - Shut down the hardware prior to driver removal.
+ * @udc: Reference to the device controller.
+ *
+ * This just masks the IUDMA IRQs and releases the clocks.  It is assumed
+ * that bcm63xx_udc_stop() has already run, and the clocks are stopped.
+ */
+static void bcm63xx_uninit_udc_hw(struct bcm63xx_udc *udc)
+{
+	set_clocks(udc, true);
+	iudma_uninit(udc);
+	set_clocks(udc, false);
+
+	clk_put(udc->usbd_clk);
+	clk_put(udc->usbh_clk);
+}
+
+/**
+ * bcm63xx_init_udc_hw - Initialize the controller hardware and data structures.
+ * @udc: Reference to the device controller.
+ */
+static int bcm63xx_init_udc_hw(struct bcm63xx_udc *udc)
+{
+	int i, rc = 0;
+	u32 val;
+
+	udc->ep0_ctrl_buf = devm_kzalloc(udc->dev, BCM63XX_MAX_CTRL_PKT,
+					 GFP_KERNEL);
+	if (!udc->ep0_ctrl_buf)
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&udc->gadget.ep_list);
+	for (i = 0; i < BCM63XX_NUM_EP; i++) {
+		struct bcm63xx_ep *bep = &udc->bep[i];
+
+		bep->ep.name = bcm63xx_ep_name[i];
+		bep->ep_num = i;
+		bep->ep.ops = &bcm63xx_udc_ep_ops;
+		list_add_tail(&bep->ep.ep_list, &udc->gadget.ep_list);
+		bep->halted = 0;
+		bep->ep.maxpacket = BCM63XX_MAX_CTRL_PKT;
+		bep->udc = udc;
+		bep->ep.desc = NULL;
+		INIT_LIST_HEAD(&bep->queue);
+	}
+
+	udc->gadget.ep0 = &udc->bep[0].ep;
+	list_del(&udc->bep[0].ep.ep_list);
+
+	udc->gadget.speed = USB_SPEED_UNKNOWN;
+	udc->ep0state = EP0_SHUTDOWN;
+
+	udc->usbh_clk = clk_get(udc->dev, "usbh");
+	if (IS_ERR(udc->usbh_clk))
+		return -EIO;
+
+	udc->usbd_clk = clk_get(udc->dev, "usbd");
+	if (IS_ERR(udc->usbd_clk)) {
+		clk_put(udc->usbh_clk);
+		return -EIO;
+	}
+
+	set_clocks(udc, true);
+
+	val = USBD_CONTROL_AUTO_CSRS_MASK |
+	      USBD_CONTROL_DONE_CSRS_MASK |
+	      (irq_coalesce ? USBD_CONTROL_RXZSCFG_MASK : 0);
+	usbd_writel(udc, val, USBD_CONTROL_REG);
+
+	val = USBD_STRAPS_APP_SELF_PWR_MASK |
+	      USBD_STRAPS_APP_RAM_IF_MASK |
+	      USBD_STRAPS_APP_CSRPRGSUP_MASK |
+	      USBD_STRAPS_APP_8BITPHY_MASK |
+	      USBD_STRAPS_APP_RMTWKUP_MASK;
+
+	if (udc->gadget.max_speed == USB_SPEED_HIGH)
+		val |= (BCM63XX_SPD_HIGH << USBD_STRAPS_SPEED_SHIFT);
+	else
+		val |= (BCM63XX_SPD_FULL << USBD_STRAPS_SPEED_SHIFT);
+	usbd_writel(udc, val, USBD_STRAPS_REG);
+
+	bcm63xx_set_ctrl_irqs(udc, false);
+
+	usbd_writel(udc, 0, USBD_EVENT_IRQ_CFG_LO_REG);
+
+	val = USBD_EVENT_IRQ_CFG_FALLING(USBD_EVENT_IRQ_ENUM_ON) |
+	      USBD_EVENT_IRQ_CFG_FALLING(USBD_EVENT_IRQ_SET_CSRS);
+	usbd_writel(udc, val, USBD_EVENT_IRQ_CFG_HI_REG);
+
+	rc = iudma_init(udc);
+	set_clocks(udc, false);
+	if (rc)
+		bcm63xx_uninit_udc_hw(udc);
+
+	return 0;
+}
+
+/***********************************************************************
+ * Standard EP gadget operations
+ ***********************************************************************/
+
+/**
+ * bcm63xx_ep_enable - Enable one endpoint.
+ * @ep: Endpoint to enable.
+ * @desc: Contains max packet, direction, etc.
+ *
+ * Most of the endpoint parameters are fixed in this controller, so there
+ * isn't much for this function to do.
+ */
+static int bcm63xx_ep_enable(struct usb_ep *ep,
+	const struct usb_endpoint_descriptor *desc)
+{
+	struct bcm63xx_ep *bep = our_ep(ep);
+	struct bcm63xx_udc *udc = bep->udc;
+	struct iudma_ch *iudma = bep->iudma;
+	unsigned long flags;
+
+	if (!ep || !desc || ep->name == bcm63xx_ep0name)
+		return -EINVAL;
+
+	if (!udc->driver)
+		return -ESHUTDOWN;
+
+	spin_lock_irqsave(&udc->lock, flags);
+	if (iudma->enabled) {
+		spin_unlock_irqrestore(&udc->lock, flags);
+		return -EINVAL;
+	}
+
+	iudma->enabled = true;
+	BUG_ON(!list_empty(&bep->queue));
+
+	iudma_reset_channel(udc, iudma);
+
+	bep->halted = 0;
+	bcm63xx_set_stall(udc, bep, false);
+	clear_bit(bep->ep_num, &udc->wedgemap);
+
+	ep->desc = desc;
+	ep->maxpacket = usb_endpoint_maxp(desc);
+
+	spin_unlock_irqrestore(&udc->lock, flags);
+	return 0;
+}
+
+/**
+ * bcm63xx_ep_disable - Disable one endpoint.
+ * @ep: Endpoint to disable.
+ */
+static int bcm63xx_ep_disable(struct usb_ep *ep)
+{
+	struct bcm63xx_ep *bep = our_ep(ep);
+	struct bcm63xx_udc *udc = bep->udc;
+	struct iudma_ch *iudma = bep->iudma;
+	struct list_head *pos, *n;
+	unsigned long flags;
+
+	if (!ep || !ep->desc)
+		return -EINVAL;
+
+	spin_lock_irqsave(&udc->lock, flags);
+	if (!iudma->enabled) {
+		spin_unlock_irqrestore(&udc->lock, flags);
+		return -EINVAL;
+	}
+	iudma->enabled = false;
+
+	iudma_reset_channel(udc, iudma);
+
+	if (!list_empty(&bep->queue)) {
+		list_for_each_safe(pos, n, &bep->queue) {
+			struct bcm63xx_req *breq =
+				list_entry(pos, struct bcm63xx_req, queue);
+
+			usb_gadget_unmap_request(&udc->gadget, &breq->req,
+						 iudma->is_tx);
+			list_del(&breq->queue);
+			breq->req.status = -ESHUTDOWN;
+
+			spin_unlock_irqrestore(&udc->lock, flags);
+			breq->req.complete(&iudma->bep->ep, &breq->req);
+			spin_lock_irqsave(&udc->lock, flags);
+		}
+	}
+	ep->desc = NULL;
+
+	spin_unlock_irqrestore(&udc->lock, flags);
+	return 0;
+}
+
+/**
+ * bcm63xx_udc_alloc_request - Allocate a new request.
+ * @ep: Endpoint associated with the request.
+ * @mem_flags: Flags to pass to kzalloc().
+ */
+static struct usb_request *bcm63xx_udc_alloc_request(struct usb_ep *ep,
+	gfp_t mem_flags)
+{
+	struct bcm63xx_req *breq;
+
+	breq = kzalloc(sizeof(*breq), mem_flags);
+	if (!breq)
+		return NULL;
+	return &breq->req;
+}
+
+/**
+ * bcm63xx_udc_free_request - Free a request.
+ * @ep: Endpoint associated with the request.
+ * @req: Request to free.
+ */
+static void bcm63xx_udc_free_request(struct usb_ep *ep,
+	struct usb_request *req)
+{
+	struct bcm63xx_req *breq = our_req(req);
+	kfree(breq);
+}
+
+/**
+ * bcm63xx_udc_queue - Queue up a new request.
+ * @ep: Endpoint associated with the request.
+ * @req: Request to add.
+ * @mem_flags: Unused.
+ *
+ * If the queue is empty, start this request immediately.  Otherwise, add
+ * it to the list.
+ *
+ * ep0 replies are sent through this function from the gadget driver, but
+ * they are treated differently because they need to be handled by the ep0
+ * state machine.  (Sometimes they are replies to control requests that
+ * were spoofed by this driver, and so they shouldn't be transmitted at all.)
+ */
+static int bcm63xx_udc_queue(struct usb_ep *ep, struct usb_request *req,
+	gfp_t mem_flags)
+{
+	struct bcm63xx_ep *bep = our_ep(ep);
+	struct bcm63xx_udc *udc = bep->udc;
+	struct bcm63xx_req *breq = our_req(req);
+	unsigned long flags;
+	int rc = 0;
+
+	if (unlikely(!req || !req->complete || !req->buf || !ep))
+		return -EINVAL;
+
+	req->actual = 0;
+	req->status = 0;
+	breq->offset = 0;
+
+	if (bep == &udc->bep[0]) {
+		/* only one reply per request, please */
+		if (udc->ep0_reply)
+			return -EINVAL;
+
+		udc->ep0_reply = req;
+		schedule_work(&udc->ep0_wq);
+		return 0;
+	}
+
+	spin_lock_irqsave(&udc->lock, flags);
+	if (!bep->iudma->enabled) {
+		rc = -ESHUTDOWN;
+		goto out;
+	}
+
+	rc = usb_gadget_map_request(&udc->gadget, req, bep->iudma->is_tx);
+	if (rc == 0) {
+		list_add_tail(&breq->queue, &bep->queue);
+		if (list_is_singular(&bep->queue))
+			iudma_write(udc, bep->iudma, breq);
+	}
+
+out:
+	spin_unlock_irqrestore(&udc->lock, flags);
+	return rc;
+}
+
+/**
+ * bcm63xx_udc_dequeue - Remove a pending request from the queue.
+ * @ep: Endpoint associated with the request.
+ * @req: Request to remove.
+ *
+ * If the request is not at the head of the queue, this is easy - just nuke
+ * it.  If the request is at the head of the queue, we'll need to stop the
+ * DMA transaction and then queue up the successor.
+ */
+static int bcm63xx_udc_dequeue(struct usb_ep *ep, struct usb_request *req)
+{
+	struct bcm63xx_ep *bep = our_ep(ep);
+	struct bcm63xx_udc *udc = bep->udc;
+	struct bcm63xx_req *breq = our_req(req), *cur;
+	unsigned long flags;
+	int rc = 0;
+
+	spin_lock_irqsave(&udc->lock, flags);
+	if (list_empty(&bep->queue)) {
+		rc = -EINVAL;
+		goto out;
+	}
+
+	cur = list_first_entry(&bep->queue, struct bcm63xx_req, queue);
+	usb_gadget_unmap_request(&udc->gadget, &breq->req, bep->iudma->is_tx);
+
+	if (breq == cur) {
+		iudma_reset_channel(udc, bep->iudma);
+		list_del(&breq->queue);
+
+		if (!list_empty(&bep->queue)) {
+			struct bcm63xx_req *next;
+
+			next = list_first_entry(&bep->queue,
+				struct bcm63xx_req, queue);
+			iudma_write(udc, bep->iudma, next);
+		}
+	} else {
+		list_del(&breq->queue);
+	}
+
+out:
+	spin_unlock_irqrestore(&udc->lock, flags);
+
+	req->status = -ESHUTDOWN;
+	req->complete(ep, req);
+
+	return rc;
+}
+
+/**
+ * bcm63xx_udc_set_halt - Enable/disable STALL flag in the hardware.
+ * @ep: Endpoint to halt.
+ * @value: Zero to clear halt; nonzero to set halt.
+ *
+ * See comments in bcm63xx_update_wedge().
+ */
+static int bcm63xx_udc_set_halt(struct usb_ep *ep, int value)
+{
+	struct bcm63xx_ep *bep = our_ep(ep);
+	struct bcm63xx_udc *udc = bep->udc;
+	unsigned long flags;
+
+	spin_lock_irqsave(&udc->lock, flags);
+	bcm63xx_set_stall(udc, bep, !!value);
+	bep->halted = value;
+	spin_unlock_irqrestore(&udc->lock, flags);
+
+	return 0;
+}
+
+/**
+ * bcm63xx_udc_set_wedge - Stall the endpoint until the next reset.
+ * @ep: Endpoint to wedge.
+ *
+ * See comments in bcm63xx_update_wedge().
+ */
+static int bcm63xx_udc_set_wedge(struct usb_ep *ep)
+{
+	struct bcm63xx_ep *bep = our_ep(ep);
+	struct bcm63xx_udc *udc = bep->udc;
+	unsigned long flags;
+
+	spin_lock_irqsave(&udc->lock, flags);
+	set_bit(bep->ep_num, &udc->wedgemap);
+	bcm63xx_set_stall(udc, bep, true);
+	spin_unlock_irqrestore(&udc->lock, flags);
+
+	return 0;
+}
+
+static const struct usb_ep_ops bcm63xx_udc_ep_ops = {
+	.enable		= bcm63xx_ep_enable,
+	.disable	= bcm63xx_ep_disable,
+
+	.alloc_request	= bcm63xx_udc_alloc_request,
+	.free_request	= bcm63xx_udc_free_request,
+
+	.queue		= bcm63xx_udc_queue,
+	.dequeue	= bcm63xx_udc_dequeue,
+
+	.set_halt	= bcm63xx_udc_set_halt,
+	.set_wedge	= bcm63xx_udc_set_wedge,
+};
+
+/***********************************************************************
+ * EP0 handling
+ ***********************************************************************/
+
+/**
+ * bcm63xx_ep0_setup_callback - Drop spinlock to invoke ->setup callback.
+ * @udc: Reference to the device controller.
+ * @ctrl: 8-byte SETUP request.
+ */
+static int bcm63xx_ep0_setup_callback(struct bcm63xx_udc *udc,
+	struct usb_ctrlrequest *ctrl)
+{
+	int rc;
+
+	spin_unlock_irq(&udc->lock);
+	rc = udc->driver->setup(&udc->gadget, ctrl);
+	spin_lock_irq(&udc->lock);
+	return rc;
+}
+
+/**
+ * bcm63xx_ep0_spoof_set_cfg - Synthesize a SET_CONFIGURATION request.
+ * @udc: Reference to the device controller.
+ *
+ * Many standard requests are handled automatically in the hardware, but
+ * we still need to pass them to the gadget driver so that it can
+ * reconfigure the interfaces/endpoints if necessary.
+ *
+ * Unfortunately we are not able to send a STALL response if the host
+ * requests an invalid configuration.  If this happens, we'll have to be
+ * content with printing a warning.
+ */
+static int bcm63xx_ep0_spoof_set_cfg(struct bcm63xx_udc *udc)
+{
+	struct usb_ctrlrequest ctrl;
+	int rc;
+
+	ctrl.bRequestType = USB_DIR_OUT | USB_RECIP_DEVICE;
+	ctrl.bRequest = USB_REQ_SET_CONFIGURATION;
+	ctrl.wValue = cpu_to_le16(udc->cfg);
+	ctrl.wIndex = 0;
+	ctrl.wLength = 0;
+
+	rc = bcm63xx_ep0_setup_callback(udc, &ctrl);
+	if (rc < 0) {
+		dev_warn_ratelimited(udc->dev,
+			"hardware auto-acked bad SET_CONFIGURATION(%d) request\n",
+			udc->cfg);
+	}
+	return rc;
+}
+
+/**
+ * bcm63xx_ep0_spoof_set_iface - Synthesize a SET_INTERFACE request.
+ * @udc: Reference to the device controller.
+ */
+static int bcm63xx_ep0_spoof_set_iface(struct bcm63xx_udc *udc)
+{
+	struct usb_ctrlrequest ctrl;
+	int rc;
+
+	ctrl.bRequestType = USB_DIR_OUT | USB_RECIP_INTERFACE;
+	ctrl.bRequest = USB_REQ_SET_INTERFACE;
+	ctrl.wValue = cpu_to_le16(udc->alt_iface);
+	ctrl.wIndex = cpu_to_le16(udc->iface);
+	ctrl.wLength = 0;
+
+	rc = bcm63xx_ep0_setup_callback(udc, &ctrl);
+	if (rc < 0) {
+		dev_warn_ratelimited(udc->dev,
+			"hardware auto-acked bad SET_INTERFACE(%d,%d) request\n",
+			udc->iface, udc->alt_iface);
+	}
+	return rc;
+}
+
+/**
+ * bcm63xx_ep0_map_write - dma_map and iudma_write a single request.
+ * @udc: Reference to the device controller.
+ * @ch_idx: IUDMA channel number.
+ * @req: USB gadget layer representation of the request.
+ */
+static void bcm63xx_ep0_map_write(struct bcm63xx_udc *udc, int ch_idx,
+	struct usb_request *req)
+{
+	struct bcm63xx_req *breq = our_req(req);
+	struct iudma_ch *iudma = &udc->iudma[ch_idx];
+
+	BUG_ON(udc->ep0_request);
+	udc->ep0_request = req;
+
+	req->actual = 0;
+	breq->offset = 0;
+	usb_gadget_map_request(&udc->gadget, req, iudma->is_tx);
+	iudma_write(udc, iudma, breq);
+}
+
+/**
+ * bcm63xx_ep0_complete - Set completion status and "stage" the callback.
+ * @udc: Reference to the device controller.
+ * @req: USB gadget layer representation of the request.
+ * @status: Status to return to the gadget driver.
+ */
+static void bcm63xx_ep0_complete(struct bcm63xx_udc *udc,
+	struct usb_request *req, int status)
+{
+	req->status = status;
+	if (status)
+		req->actual = 0;
+	if (req->complete) {
+		spin_unlock_irq(&udc->lock);
+		req->complete(&udc->bep[0].ep, req);
+		spin_lock_irq(&udc->lock);
+	}
+}
+
+/**
+ * bcm63xx_ep0_nuke_reply - Abort request from the gadget driver due to
+ *   reset/shutdown.
+ * @udc: Reference to the device controller.
+ * @is_tx: Nonzero for TX (IN), zero for RX (OUT).
+ */
+static void bcm63xx_ep0_nuke_reply(struct bcm63xx_udc *udc, int is_tx)
+{
+	struct usb_request *req = udc->ep0_reply;
+
+	udc->ep0_reply = NULL;
+	usb_gadget_unmap_request(&udc->gadget, req, is_tx);
+	if (udc->ep0_request == req) {
+		udc->ep0_req_completed = 0;
+		udc->ep0_request = NULL;
+	}
+	bcm63xx_ep0_complete(udc, req, -ESHUTDOWN);
+}
+
+/**
+ * bcm63xx_ep0_read_complete - Close out the pending ep0 request; return
+ *   transfer len.
+ * @udc: Reference to the device controller.
+ */
+static int bcm63xx_ep0_read_complete(struct bcm63xx_udc *udc)
+{
+	struct usb_request *req = udc->ep0_request;
+
+	udc->ep0_req_completed = 0;
+	udc->ep0_request = NULL;
+
+	return req->actual;
+}
+
+/**
+ * bcm63xx_ep0_internal_request - Helper function to submit an ep0 request.
+ * @udc: Reference to the device controller.
+ * @ch_idx: IUDMA channel number.
+ * @length: Number of bytes to TX/RX.
+ *
+ * Used for simple transfers performed by the ep0 worker.  This will always
+ * use ep0_ctrl_req / ep0_ctrl_buf.
+ */
+static void bcm63xx_ep0_internal_request(struct bcm63xx_udc *udc, int ch_idx,
+	int length)
+{
+	struct usb_request *req = &udc->ep0_ctrl_req.req;
+
+	req->buf = udc->ep0_ctrl_buf;
+	req->length = length;
+	req->complete = NULL;
+
+	bcm63xx_ep0_map_write(udc, ch_idx, req);
+}
+
+/**
+ * bcm63xx_ep0_do_setup - Parse new SETUP packet and decide how to handle it.
+ * @udc: Reference to the device controller.
+ *
+ * EP0_IDLE probably shouldn't ever happen.  EP0_REQUEUE means we're ready
+ * for the next packet.  Anything else means the transaction requires multiple
+ * stages of handling.
+ */
+static enum bcm63xx_ep0_state bcm63xx_ep0_do_setup(struct bcm63xx_udc *udc)
+{
+	int rc;
+	struct usb_ctrlrequest *ctrl = (void *)udc->ep0_ctrl_buf;
+
+	rc = bcm63xx_ep0_read_complete(udc);
+
+	if (rc < 0) {
+		dev_err(udc->dev, "missing SETUP packet\n");
+		return EP0_IDLE;
+	}
+
+	/*
+	 * Handle 0-byte IN STATUS acknowledgement.  The hardware doesn't
+	 * ALWAYS deliver these 100% of the time, so if we happen to see one,
+	 * just throw it away.
+	 */
+	if (rc == 0)
+		return EP0_REQUEUE;
+
+	/* Drop malformed SETUP packets */
+	if (rc != sizeof(*ctrl)) {
+		dev_warn_ratelimited(udc->dev,
+			"malformed SETUP packet (%d bytes)\n", rc);
+		return EP0_REQUEUE;
+	}
+
+	/* Process new SETUP packet arriving on ep0 */
+	rc = bcm63xx_ep0_setup_callback(udc, ctrl);
+	if (rc < 0) {
+		bcm63xx_set_stall(udc, &udc->bep[0], true);
+		return EP0_REQUEUE;
+	}
+
+	if (!ctrl->wLength)
+		return EP0_REQUEUE;
+	else if (ctrl->bRequestType & USB_DIR_IN)
+		return EP0_IN_DATA_PHASE_SETUP;
+	else
+		return EP0_OUT_DATA_PHASE_SETUP;
+}
+
+/**
+ * bcm63xx_ep0_do_idle - Check for outstanding requests if ep0 is idle.
+ * @udc: Reference to the device controller.
+ *
+ * In state EP0_IDLE, the RX descriptor is either pending, or has been
+ * filled with a SETUP packet from the host.  This function handles new
+ * SETUP packets, control IRQ events (which can generate fake SETUP packets),
+ * and reset/shutdown events.
+ *
+ * Returns 0 if work was done; -EAGAIN if nothing to do.
+ */
+static int bcm63xx_ep0_do_idle(struct bcm63xx_udc *udc)
+{
+	if (udc->ep0_req_reset) {
+		udc->ep0_req_reset = 0;
+	} else if (udc->ep0_req_set_cfg) {
+		udc->ep0_req_set_cfg = 0;
+		if (bcm63xx_ep0_spoof_set_cfg(udc) >= 0)
+			udc->ep0state = EP0_IN_FAKE_STATUS_PHASE;
+	} else if (udc->ep0_req_set_iface) {
+		udc->ep0_req_set_iface = 0;
+		if (bcm63xx_ep0_spoof_set_iface(udc) >= 0)
+			udc->ep0state = EP0_IN_FAKE_STATUS_PHASE;
+	} else if (udc->ep0_req_completed) {
+		udc->ep0state = bcm63xx_ep0_do_setup(udc);
+		return udc->ep0state == EP0_IDLE ? -EAGAIN : 0;
+	} else if (udc->ep0_req_shutdown) {
+		udc->ep0_req_shutdown = 0;
+		udc->ep0_req_completed = 0;
+		udc->ep0_request = NULL;
+		iudma_reset_channel(udc, &udc->iudma[IUDMA_EP0_RXCHAN]);
+		usb_gadget_unmap_request(&udc->gadget,
+			&udc->ep0_ctrl_req.req, 0);
+
+		/* bcm63xx_udc_pullup() is waiting for this */
+		mb();
+		udc->ep0state = EP0_SHUTDOWN;
+	} else if (udc->ep0_reply) {
+		/*
+		 * This could happen if a USB RESET shows up during an ep0
+		 * transaction (especially if a laggy driver like gadgetfs
+		 * is in use).
+		 */
+		dev_warn(udc->dev, "nuking unexpected reply\n");
+		bcm63xx_ep0_nuke_reply(udc, 0);
+	} else {
+		return -EAGAIN;
+	}
+
+	return 0;
+}
+
+/**
+ * bcm63xx_ep0_one_round - Handle the current ep0 state.
+ * @udc: Reference to the device controller.
+ *
+ * Returns 0 if work was done; -EAGAIN if nothing to do.
+ */
+static int bcm63xx_ep0_one_round(struct bcm63xx_udc *udc)
+{
+	enum bcm63xx_ep0_state ep0state = udc->ep0state;
+	bool shutdown = udc->ep0_req_reset || udc->ep0_req_shutdown;
+
+	switch (udc->ep0state) {
+	case EP0_REQUEUE:
+		/* set up descriptor to receive SETUP packet */
+		bcm63xx_ep0_internal_request(udc, IUDMA_EP0_RXCHAN,
+					     BCM63XX_MAX_CTRL_PKT);
+		ep0state = EP0_IDLE;
+		break;
+	case EP0_IDLE:
+		return bcm63xx_ep0_do_idle(udc);
+	case EP0_IN_DATA_PHASE_SETUP:
+		/*
+		 * Normal case: TX request is in ep0_reply (queued by the
+		 * callback), or will be queued shortly.  When it's here,
+		 * send it to the HW and go to EP0_IN_DATA_PHASE_COMPLETE.
+		 *
+		 * Shutdown case: Stop waiting for the reply.  Just
+		 * REQUEUE->IDLE.  The gadget driver is NOT expected to
+		 * queue anything else now.
+		 */
+		if (udc->ep0_reply) {
+			bcm63xx_ep0_map_write(udc, IUDMA_EP0_TXCHAN,
+					      udc->ep0_reply);
+			ep0state = EP0_IN_DATA_PHASE_COMPLETE;
+		} else if (shutdown) {
+			ep0state = EP0_REQUEUE;
+		}
+		break;
+	case EP0_IN_DATA_PHASE_COMPLETE: {
+		/*
+		 * Normal case: TX packet (ep0_reply) is in flight; wait for
+		 * it to finish, then go back to REQUEUE->IDLE.
+		 *
+		 * Shutdown case: Reset the TX channel, send -ESHUTDOWN
+		 * completion to the gadget driver, then REQUEUE->IDLE.
+		 */
+		if (udc->ep0_req_completed) {
+			udc->ep0_reply = NULL;
+			bcm63xx_ep0_read_complete(udc);
+			/*
+			 * the "ack" sometimes gets eaten (see
+			 * bcm63xx_ep0_do_idle)
+			 */
+			ep0state = EP0_REQUEUE;
+		} else if (shutdown) {
+			iudma_reset_channel(udc, &udc->iudma[IUDMA_EP0_TXCHAN]);
+			bcm63xx_ep0_nuke_reply(udc, 1);
+			ep0state = EP0_REQUEUE;
+		}
+		break;
+	}
+	case EP0_OUT_DATA_PHASE_SETUP:
+		/* Similar behavior to EP0_IN_DATA_PHASE_SETUP */
+		if (udc->ep0_reply) {
+			bcm63xx_ep0_map_write(udc, IUDMA_EP0_RXCHAN,
+					      udc->ep0_reply);
+			ep0state = EP0_OUT_DATA_PHASE_COMPLETE;
+		} else if (shutdown) {
+			ep0state = EP0_REQUEUE;
+		}
+		break;
+	case EP0_OUT_DATA_PHASE_COMPLETE: {
+		/* Similar behavior to EP0_IN_DATA_PHASE_COMPLETE */
+		if (udc->ep0_req_completed) {
+			udc->ep0_reply = NULL;
+			bcm63xx_ep0_read_complete(udc);
+
+			/* send 0-byte ack to host */
+			bcm63xx_ep0_internal_request(udc, IUDMA_EP0_TXCHAN, 0);
+			ep0state = EP0_OUT_STATUS_PHASE;
+		} else if (shutdown) {
+			iudma_reset_channel(udc, &udc->iudma[IUDMA_EP0_RXCHAN]);
+			bcm63xx_ep0_nuke_reply(udc, 0);
+			ep0state = EP0_REQUEUE;
+		}
+		break;
+	}
+	case EP0_OUT_STATUS_PHASE:
+		/*
+		 * Normal case: 0-byte OUT ack packet is in flight; wait
+		 * for it to finish, then go back to REQUEUE->IDLE.
+		 *
+		 * Shutdown case: just cancel the transmission.  Don't bother
+		 * calling the completion, because it originated from this
+		 * function anyway.  Then go back to REQUEUE->IDLE.
+		 */
+		if (udc->ep0_req_completed) {
+			bcm63xx_ep0_read_complete(udc);
+			ep0state = EP0_REQUEUE;
+		} else if (shutdown) {
+			iudma_reset_channel(udc, &udc->iudma[IUDMA_EP0_TXCHAN]);
+			udc->ep0_request = NULL;
+			ep0state = EP0_REQUEUE;
+		}
+		break;
+	case EP0_IN_FAKE_STATUS_PHASE: {
+		/*
+		 * Normal case: we spoofed a SETUP packet and are now
+		 * waiting for the gadget driver to send a 0-byte reply.
+		 * This doesn't actually get sent to the HW because the
+		 * HW has already sent its own reply.  Once we get the
+		 * response, return to IDLE.
+		 *
+		 * Shutdown case: return to IDLE immediately.
+		 *
+		 * Note that the ep0 RX descriptor has remained queued
+		 * (and possibly unfilled) during this entire transaction.
+		 * The HW datapath (IUDMA) never even sees SET_CONFIGURATION
+		 * or SET_INTERFACE transactions.
+		 */
+		struct usb_request *r = udc->ep0_reply;
+
+		if (!r) {
+			if (shutdown)
+				ep0state = EP0_IDLE;
+			break;
+		}
+
+		bcm63xx_ep0_complete(udc, r, 0);
+		udc->ep0_reply = NULL;
+		ep0state = EP0_IDLE;
+		break;
+	}
+	case EP0_SHUTDOWN:
+		break;
+	}
+
+	if (udc->ep0state == ep0state)
+		return -EAGAIN;
+
+	udc->ep0state = ep0state;
+	return 0;
+}
+
+/**
+ * bcm63xx_ep0_process - ep0 worker thread / state machine.
+ * @w: Workqueue struct.
+ *
+ * bcm63xx_ep0_process is triggered any time an event occurs on ep0.  It
+ * is used to synchronize ep0 events and ensure that both HW and SW events
+ * occur in a well-defined order.  When the ep0 IUDMA queues are idle, it may
+ * synthesize SET_CONFIGURATION / SET_INTERFACE requests that were consumed
+ * by the USBD hardware.
+ *
+ * The worker function will continue iterating around the state machine
+ * until there is nothing left to do.  Usually "nothing left to do" means
+ * that we're waiting for a new event from the hardware.
+ */
+static void bcm63xx_ep0_process(struct work_struct *w)
+{
+	struct bcm63xx_udc *udc = container_of(w, struct bcm63xx_udc, ep0_wq);
+	spin_lock_irq(&udc->lock);
+	while (bcm63xx_ep0_one_round(udc) == 0)
+		;
+	spin_unlock_irq(&udc->lock);
+}
+
+/***********************************************************************
+ * Standard UDC gadget operations
+ ***********************************************************************/
+
+/**
+ * bcm63xx_udc_get_frame - Read current SOF frame number from the HW.
+ * @gadget: USB slave device.
+ */
+static int bcm63xx_udc_get_frame(struct usb_gadget *gadget)
+{
+	struct bcm63xx_udc *udc = gadget_to_udc(gadget);
+
+	return (usbd_readl(udc, USBD_STATUS_REG) &
+		USBD_STATUS_SOF_MASK) >> USBD_STATUS_SOF_SHIFT;
+}
+
+/**
+ * bcm63xx_udc_pullup - Enable/disable pullup on D+ line.
+ * @gadget: USB slave device.
+ * @is_on: 0 to disable pullup, 1 to enable.
+ *
+ * See notes in bcm63xx_select_pullup().
+ */
+static int bcm63xx_udc_pullup(struct usb_gadget *gadget, int is_on)
+{
+	struct bcm63xx_udc *udc = gadget_to_udc(gadget);
+	unsigned long flags;
+	int i, rc = -EINVAL;
+
+	spin_lock_irqsave(&udc->lock, flags);
+	if (is_on && udc->ep0state == EP0_SHUTDOWN) {
+		udc->gadget.speed = USB_SPEED_UNKNOWN;
+		udc->ep0state = EP0_REQUEUE;
+		bcm63xx_fifo_setup(udc);
+		bcm63xx_fifo_reset(udc);
+		bcm63xx_ep_setup(udc);
+
+		bitmap_zero(&udc->wedgemap, BCM63XX_NUM_EP);
+		for (i = 0; i < BCM63XX_NUM_EP; i++)
+			bcm63xx_set_stall(udc, &udc->bep[i], false);
+
+		bcm63xx_set_ctrl_irqs(udc, true);
+		bcm63xx_select_pullup(gadget_to_udc(gadget), true);
+		rc = 0;
+	} else if (!is_on && udc->ep0state != EP0_SHUTDOWN) {
+		bcm63xx_select_pullup(gadget_to_udc(gadget), false);
+
+		udc->ep0_req_shutdown = 1;
+		spin_unlock_irqrestore(&udc->lock, flags);
+
+		while (1) {
+			schedule_work(&udc->ep0_wq);
+			if (udc->ep0state == EP0_SHUTDOWN)
+				break;
+			msleep(50);
+		}
+		bcm63xx_set_ctrl_irqs(udc, false);
+		cancel_work_sync(&udc->ep0_wq);
+		return 0;
+	}
+
+	spin_unlock_irqrestore(&udc->lock, flags);
+	return rc;
+}
+
+/**
+ * bcm63xx_udc_start - Start the controller.
+ * @gadget: USB slave device.
+ * @driver: Driver for USB slave devices.
+ */
+static int bcm63xx_udc_start(struct usb_gadget *gadget,
+		struct usb_gadget_driver *driver)
+{
+	struct bcm63xx_udc *udc = gadget_to_udc(gadget);
+	unsigned long flags;
+
+	if (!driver || driver->max_speed < USB_SPEED_HIGH ||
+	    !driver->setup)
+		return -EINVAL;
+	if (!udc)
+		return -ENODEV;
+	if (udc->driver)
+		return -EBUSY;
+
+	spin_lock_irqsave(&udc->lock, flags);
+
+	set_clocks(udc, true);
+	bcm63xx_fifo_setup(udc);
+	bcm63xx_ep_init(udc);
+	bcm63xx_ep_setup(udc);
+	bcm63xx_fifo_reset(udc);
+	bcm63xx_select_phy_mode(udc, true);
+
+	udc->driver = driver;
+	driver->driver.bus = NULL;
+	udc->gadget.dev.driver = &driver->driver;
+	udc->gadget.dev.of_node = udc->dev->of_node;
+
+	spin_unlock_irqrestore(&udc->lock, flags);
+
+	return 0;
+}
+
+/**
+ * bcm63xx_udc_stop - Shut down the controller.
+ * @gadget: USB slave device.
+ * @driver: Driver for USB slave devices.
+ */
+static int bcm63xx_udc_stop(struct usb_gadget *gadget,
+		struct usb_gadget_driver *driver)
+{
+	struct bcm63xx_udc *udc = gadget_to_udc(gadget);
+	unsigned long flags;
+
+	spin_lock_irqsave(&udc->lock, flags);
+
+	udc->driver = NULL;
+	udc->gadget.dev.driver = NULL;
+
+	/*
+	 * If we switch the PHY too abruptly after dropping D+, the host
+	 * will often complain:
+	 *
+	 *     hub 1-0:1.0: port 1 disabled by hub (EMI?), re-enabling...
+	 */
+	msleep(100);
+
+	bcm63xx_select_phy_mode(udc, false);
+	set_clocks(udc, false);
+
+	spin_unlock_irqrestore(&udc->lock, flags);
+
+	return 0;
+}
+
+static const struct usb_gadget_ops bcm63xx_udc_ops = {
+	.get_frame	= bcm63xx_udc_get_frame,
+	.pullup		= bcm63xx_udc_pullup,
+	.udc_start	= bcm63xx_udc_start,
+	.udc_stop	= bcm63xx_udc_stop,
+};
+
+/***********************************************************************
+ * IRQ handling
+ ***********************************************************************/
+
+/**
+ * bcm63xx_update_cfg_iface - Read current configuration/interface settings.
+ * @udc: Reference to the device controller.
+ *
+ * This controller intercepts SET_CONFIGURATION and SET_INTERFACE messages.
+ * The driver never sees the raw control packets coming in on the ep0
+ * IUDMA channel, but at least we get an interrupt event to tell us that
+ * new values are waiting in the USBD_STATUS register.
+ */
+static void bcm63xx_update_cfg_iface(struct bcm63xx_udc *udc)
+{
+	u32 reg = usbd_readl(udc, USBD_STATUS_REG);
+
+	udc->cfg = (reg & USBD_STATUS_CFG_MASK) >> USBD_STATUS_CFG_SHIFT;
+	udc->iface = (reg & USBD_STATUS_INTF_MASK) >> USBD_STATUS_INTF_SHIFT;
+	udc->alt_iface = (reg & USBD_STATUS_ALTINTF_MASK) >>
+			 USBD_STATUS_ALTINTF_SHIFT;
+	bcm63xx_ep_setup(udc);
+}
+
+/**
+ * bcm63xx_update_link_speed - Check to see if the link speed has changed.
+ * @udc: Reference to the device controller.
+ *
+ * The link speed update coincides with a SETUP IRQ.  Returns 1 if the
+ * speed has changed, so that the caller can update the endpoint settings.
+ */
+static int bcm63xx_update_link_speed(struct bcm63xx_udc *udc)
+{
+	u32 reg = usbd_readl(udc, USBD_STATUS_REG);
+	enum usb_device_speed oldspeed = udc->gadget.speed;
+
+	switch ((reg & USBD_STATUS_SPD_MASK) >> USBD_STATUS_SPD_SHIFT) {
+	case BCM63XX_SPD_HIGH:
+		udc->gadget.speed = USB_SPEED_HIGH;
+		break;
+	case BCM63XX_SPD_FULL:
+		udc->gadget.speed = USB_SPEED_FULL;
+		break;
+	default:
+		/* this should never happen */
+		udc->gadget.speed = USB_SPEED_UNKNOWN;
+		dev_err(udc->dev,
+			"received SETUP packet with invalid link speed\n");
+		return 0;
+	}
+
+	if (udc->gadget.speed != oldspeed) {
+		dev_info(udc->dev, "link up, %s-speed mode\n",
+			 udc->gadget.speed == USB_SPEED_HIGH ? "high" : "full");
+		return 1;
+	} else {
+		return 0;
+	}
+}
+
+/**
+ * bcm63xx_update_wedge - Iterate through wedged endpoints.
+ * @udc: Reference to the device controller.
+ * @new_status: true to "refresh" wedge status; false to clear it.
+ *
+ * On a SETUP interrupt, we need to manually "refresh" the wedge status
+ * because the controller hardware is designed to automatically clear
+ * stalls in response to a CLEAR_FEATURE request from the host.
+ *
+ * On a RESET interrupt, we do want to restore all wedged endpoints.
+ */
+static void bcm63xx_update_wedge(struct bcm63xx_udc *udc, bool new_status)
+{
+	int i;
+
+	for_each_set_bit(i, &udc->wedgemap, BCM63XX_NUM_EP) {
+		bcm63xx_set_stall(udc, &udc->bep[i], new_status);
+		if (!new_status)
+			clear_bit(i, &udc->wedgemap);
+	}
+}
+
+/**
+ * bcm63xx_udc_ctrl_isr - ISR for control path events (USBD).
+ * @irq: IRQ number (unused).
+ * @dev_id: Reference to the device controller.
+ *
+ * This is where we handle link (VBUS) down, USB reset, speed changes,
+ * SET_CONFIGURATION, and SET_INTERFACE events.
+ */
+static irqreturn_t bcm63xx_udc_ctrl_isr(int irq, void *dev_id)
+{
+	struct bcm63xx_udc *udc = dev_id;
+	u32 stat;
+	bool disconnected = false;
+
+	stat = usbd_readl(udc, USBD_EVENT_IRQ_STATUS_REG) &
+	       usbd_readl(udc, USBD_EVENT_IRQ_MASK_REG);
+
+	usbd_writel(udc, stat, USBD_EVENT_IRQ_STATUS_REG);
+
+	spin_lock(&udc->lock);
+	if (stat & BIT(USBD_EVENT_IRQ_USB_LINK)) {
+		/* VBUS toggled */
+
+		if (!(usbd_readl(udc, USBD_EVENTS_REG) &
+		      USBD_EVENTS_USB_LINK_MASK) &&
+		      udc->gadget.speed != USB_SPEED_UNKNOWN)
+			dev_info(udc->dev, "link down\n");
+
+		udc->gadget.speed = USB_SPEED_UNKNOWN;
+		disconnected = true;
+	}
+	if (stat & BIT(USBD_EVENT_IRQ_USB_RESET)) {
+		bcm63xx_fifo_setup(udc);
+		bcm63xx_fifo_reset(udc);
+		bcm63xx_ep_setup(udc);
+
+		bcm63xx_update_wedge(udc, false);
+
+		udc->ep0_req_reset = 1;
+		schedule_work(&udc->ep0_wq);
+		disconnected = true;
+	}
+	if (stat & BIT(USBD_EVENT_IRQ_SETUP)) {
+		if (bcm63xx_update_link_speed(udc)) {
+			bcm63xx_fifo_setup(udc);
+			bcm63xx_ep_setup(udc);
+		}
+		bcm63xx_update_wedge(udc, true);
+	}
+	if (stat & BIT(USBD_EVENT_IRQ_SETCFG)) {
+		bcm63xx_update_cfg_iface(udc);
+		udc->ep0_req_set_cfg = 1;
+		schedule_work(&udc->ep0_wq);
+	}
+	if (stat & BIT(USBD_EVENT_IRQ_SETINTF)) {
+		bcm63xx_update_cfg_iface(udc);
+		udc->ep0_req_set_iface = 1;
+		schedule_work(&udc->ep0_wq);
+	}
+	spin_unlock(&udc->lock);
+
+	if (disconnected && udc->driver)
+		udc->driver->disconnect(&udc->gadget);
+
+	return IRQ_HANDLED;
+}
+
+/**
+ * bcm63xx_udc_data_isr - ISR for data path events (IUDMA).
+ * @irq: IRQ number (unused).
+ * @dev_id: Reference to the IUDMA channel that generated the interrupt.
+ *
+ * For the two ep0 channels, we have special handling that triggers the
+ * ep0 worker thread.  For normal bulk/intr channels, either queue up
+ * the next buffer descriptor for the transaction (incomplete transaction),
+ * or invoke the completion callback (complete transactions).
+ */
+static irqreturn_t bcm63xx_udc_data_isr(int irq, void *dev_id)
+{
+	struct iudma_ch *iudma = dev_id;
+	struct bcm63xx_udc *udc = iudma->udc;
+	struct bcm63xx_ep *bep;
+	struct usb_request *req = NULL;
+	struct bcm63xx_req *breq = NULL;
+	int rc;
+	bool is_done = false;
+
+	spin_lock(&udc->lock);
+
+	usb_dmac_writel(udc, ENETDMAC_IR_BUFDONE_MASK,
+			ENETDMAC_IR_REG(iudma->ch_idx));
+	bep = iudma->bep;
+	rc = iudma_read(udc, iudma);
+
+	/* special handling for EP0 RX (0) and TX (1) */
+	if (iudma->ch_idx == IUDMA_EP0_RXCHAN ||
+	    iudma->ch_idx == IUDMA_EP0_TXCHAN) {
+		req = udc->ep0_request;
+		breq = our_req(req);
+
+		/* a single request could require multiple submissions */
+		if (rc >= 0) {
+			req->actual += rc;
+
+			if (req->actual >= req->length || breq->bd_bytes > rc) {
+				udc->ep0_req_completed = 1;
+				is_done = true;
+				schedule_work(&udc->ep0_wq);
+
+				/* "actual" on a ZLP is 1 byte */
+				req->actual = min(req->actual, req->length);
+			} else {
+				/* queue up the next BD (same request) */
+				iudma_write(udc, iudma, breq);
+			}
+		}
+	} else if (!list_empty(&bep->queue)) {
+		breq = list_first_entry(&bep->queue, struct bcm63xx_req, queue);
+		req = &breq->req;
+
+		if (rc >= 0) {
+			req->actual += rc;
+
+			if (req->actual >= req->length || breq->bd_bytes > rc) {
+				is_done = true;
+				list_del(&breq->queue);
+
+				req->actual = min(req->actual, req->length);
+
+				if (!list_empty(&bep->queue)) {
+					struct bcm63xx_req *next;
+
+					next = list_first_entry(&bep->queue,
+						struct bcm63xx_req, queue);
+					iudma_write(udc, iudma, next);
+				}
+			} else {
+				iudma_write(udc, iudma, breq);
+			}
+		}
+	}
+	spin_unlock(&udc->lock);
+
+	if (is_done) {
+		usb_gadget_unmap_request(&udc->gadget, req, iudma->is_tx);
+		if (req->complete)
+			req->complete(&bep->ep, req);
+	}
+
+	return IRQ_HANDLED;
+}
+
+/***********************************************************************
+ * Debug filesystem
+ ***********************************************************************/
+
+/*
+ * bcm63xx_usbd_dbg_show - Show USBD controller state.
+ * @s: seq_file to which the information will be written.
+ * @p: Unused.
+ *
+ * This file nominally shows up as /sys/kernel/debug/bcm63xx_udc/usbd
+ */
+static int bcm63xx_usbd_dbg_show(struct seq_file *s, void *p)
+{
+	struct bcm63xx_udc *udc = s->private;
+
+	if (!udc->driver)
+		return -ENODEV;
+
+	seq_printf(s, "ep0 state: %s\n",
+		   bcm63xx_ep0_state_names[udc->ep0state]);
+	seq_printf(s, "  pending requests: %s%s%s%s%s%s%s\n",
+		   udc->ep0_req_reset ? "reset " : "",
+		   udc->ep0_req_set_cfg ? "set_cfg " : "",
+		   udc->ep0_req_set_iface ? "set_iface " : "",
+		   udc->ep0_req_shutdown ? "shutdown " : "",
+		   udc->ep0_request ? "pending " : "",
+		   udc->ep0_req_completed ? "completed " : "",
+		   udc->ep0_reply ? "reply " : "");
+	seq_printf(s, "cfg: %d; iface: %d; alt_iface: %d\n",
+		   udc->cfg, udc->iface, udc->alt_iface);
+	seq_printf(s, "regs:\n");
+	seq_printf(s, "  control: %08x; straps: %08x; status: %08x\n",
+		   usbd_readl(udc, USBD_CONTROL_REG),
+		   usbd_readl(udc, USBD_STRAPS_REG),
+		   usbd_readl(udc, USBD_STATUS_REG));
+	seq_printf(s, "  events:  %08x; stall:  %08x\n",
+		   usbd_readl(udc, USBD_EVENTS_REG),
+		   usbd_readl(udc, USBD_STALL_REG));
+
+	return 0;
+}
+
+/*
+ * bcm63xx_iudma_dbg_show - Show IUDMA status and descriptors.
+ * @s: seq_file to which the information will be written.
+ * @p: Unused.
+ *
+ * This file nominally shows up as /sys/kernel/debug/bcm63xx_udc/iudma
+ */
+static int bcm63xx_iudma_dbg_show(struct seq_file *s, void *p)
+{
+	struct bcm63xx_udc *udc = s->private;
+	int ch_idx, i;
+	u32 sram2, sram3;
+
+	if (!udc->driver)
+		return -ENODEV;
+
+	for (ch_idx = 0; ch_idx < BCM63XX_NUM_IUDMA; ch_idx++) {
+		struct iudma_ch *iudma = &udc->iudma[ch_idx];
+		struct list_head *pos;
+
+		seq_printf(s, "IUDMA channel %d -- ", ch_idx);
+		switch (iudma_defaults[ch_idx].ep_type) {
+		case BCMEP_CTRL:
+			seq_printf(s, "control");
+			break;
+		case BCMEP_BULK:
+			seq_printf(s, "bulk");
+			break;
+		case BCMEP_INTR:
+			seq_printf(s, "interrupt");
+			break;
+		}
+		seq_printf(s, ch_idx & 0x01 ? " tx" : " rx");
+		seq_printf(s, " [ep%d]:\n",
+			   max_t(int, iudma_defaults[ch_idx].ep_num, 0));
+		seq_printf(s, "  cfg: %08x; irqstat: %08x; irqmask: %08x; maxburst: %08x\n",
+			   usb_dmac_readl(udc, ENETDMAC_CHANCFG_REG(ch_idx)),
+			   usb_dmac_readl(udc, ENETDMAC_IR_REG(ch_idx)),
+			   usb_dmac_readl(udc, ENETDMAC_IRMASK_REG(ch_idx)),
+			   usb_dmac_readl(udc, ENETDMAC_MAXBURST_REG(ch_idx)));
+
+		sram2 = usb_dmas_readl(udc, ENETDMAS_SRAM2_REG(ch_idx));
+		sram3 = usb_dmas_readl(udc, ENETDMAS_SRAM3_REG(ch_idx));
+		seq_printf(s, "  base: %08x; index: %04x_%04x; desc: %04x_%04x %08x\n",
+			   usb_dmas_readl(udc, ENETDMAS_RSTART_REG(ch_idx)),
+			   sram2 >> 16, sram2 & 0xffff,
+			   sram3 >> 16, sram3 & 0xffff,
+			   usb_dmas_readl(udc, ENETDMAS_SRAM4_REG(ch_idx)));
+		seq_printf(s, "  desc: %d/%d used", iudma->n_bds_used,
+			   iudma->n_bds);
+
+		if (iudma->bep) {
+			i = 0;
+			list_for_each(pos, &iudma->bep->queue)
+				i++;
+			seq_printf(s, "; %d queued\n", i);
+		} else {
+			seq_printf(s, "\n");
+		}
+
+		for (i = 0; i < iudma->n_bds; i++) {
+			struct bcm_enet_desc *d = &iudma->bd_ring[i];
+
+			seq_printf(s, "  %03x (%02x): len_stat: %04x_%04x; pa %08x",
+				   i * sizeof(*d), i,
+				   d->len_stat >> 16, d->len_stat & 0xffff,
+				   d->address);
+			if (d == iudma->read_bd)
+				seq_printf(s, "   <<RD");
+			if (d == iudma->write_bd)
+				seq_printf(s, "   <<WR");
+			seq_printf(s, "\n");
+		}
+
+		seq_printf(s, "\n");
+	}
+
+	return 0;
+}
+
+static int bcm63xx_usbd_dbg_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, bcm63xx_usbd_dbg_show, inode->i_private);
+}
+
+static int bcm63xx_iudma_dbg_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, bcm63xx_iudma_dbg_show, inode->i_private);
+}
+
+static const struct file_operations usbd_dbg_fops = {
+	.owner		= THIS_MODULE,
+	.open		= bcm63xx_usbd_dbg_open,
+	.llseek		= seq_lseek,
+	.read		= seq_read,
+	.release	= single_release,
+};
+
+static const struct file_operations iudma_dbg_fops = {
+	.owner		= THIS_MODULE,
+	.open		= bcm63xx_iudma_dbg_open,
+	.llseek		= seq_lseek,
+	.read		= seq_read,
+	.release	= single_release,
+};
+
+
+/**
+ * bcm63xx_udc_init_debugfs - Create debugfs entries.
+ * @udc: Reference to the device controller.
+ */
+static void bcm63xx_udc_init_debugfs(struct bcm63xx_udc *udc)
+{
+	struct dentry *root, *usbd, *iudma;
+
+	if (!IS_ENABLED(CONFIG_USB_GADGET_DEBUG_FS))
+		return;
+
+	root = debugfs_create_dir(udc->gadget.name, NULL);
+	if (IS_ERR(root) || !root)
+		goto err_root;
+
+	usbd = debugfs_create_file("usbd", 0400, root, udc,
+			&usbd_dbg_fops);
+	if (!usbd)
+		goto err_usbd;
+	iudma = debugfs_create_file("iudma", 0400, root, udc,
+			&iudma_dbg_fops);
+	if (!iudma)
+		goto err_iudma;
+
+	udc->debugfs_root = root;
+	udc->debugfs_usbd = usbd;
+	udc->debugfs_iudma = iudma;
+	return;
+err_iudma:
+	debugfs_remove(usbd);
+err_usbd:
+	debugfs_remove(root);
+err_root:
+	dev_err(udc->dev, "debugfs is not available\n");
+}
+
+/**
+ * bcm63xx_udc_cleanup_debugfs - Remove debugfs entries.
+ * @udc: Reference to the device controller.
+ *
+ * debugfs_remove() is safe to call with a NULL argument.
+ */
+static void bcm63xx_udc_cleanup_debugfs(struct bcm63xx_udc *udc)
+{
+	debugfs_remove(udc->debugfs_iudma);
+	debugfs_remove(udc->debugfs_usbd);
+	debugfs_remove(udc->debugfs_root);
+	udc->debugfs_iudma = NULL;
+	udc->debugfs_usbd = NULL;
+	udc->debugfs_root = NULL;
+}
+
+/***********************************************************************
+ * Driver init/exit
+ ***********************************************************************/
+
+/**
+ * bcm63xx_udc_gadget_release - Called from device_release().
+ * @dev: Unused.
+ *
+ * We get a warning if this function doesn't exist, but it's empty because
+ * we don't have to free any of the memory allocated with the devm_* APIs.
+ */
+static void bcm63xx_udc_gadget_release(struct device *dev)
+{
+}
+
+/**
+ * bcm63xx_udc_probe - Initialize a new instance of the UDC.
+ * @pdev: Platform device struct from the bcm63xx BSP code.
+ *
+ * Note that platform data is required, because pd.port_no varies from chip
+ * to chip and is used to switch the correct USB port to device mode.
+ */
+static int __devinit bcm63xx_udc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct bcm63xx_usbd_platform_data *pd = dev->platform_data;
+	struct bcm63xx_udc *udc;
+	struct resource *res;
+	int rc = -ENOMEM, i, irq;
+
+	udc = devm_kzalloc(dev, sizeof(*udc), GFP_KERNEL);
+	if (!udc) {
+		dev_err(dev, "cannot allocate memory\n");
+		return -ENOMEM;
+	}
+
+	platform_set_drvdata(pdev, udc);
+	udc->dev = dev;
+	udc->pd = pd;
+
+	if (!pd) {
+		dev_err(dev, "missing platform data\n");
+		return -EINVAL;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(dev, "error finding USBD resource\n");
+		return -ENXIO;
+	}
+	udc->usbd_regs = devm_request_and_ioremap(dev, res);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	if (!res) {
+		dev_err(dev, "error finding IUDMA resource\n");
+		return -ENXIO;
+	}
+	udc->iudma_regs = devm_request_and_ioremap(dev, res);
+
+	if (!udc->usbd_regs || !udc->iudma_regs) {
+		dev_err(dev, "error requesting resources\n");
+		return -ENXIO;
+	}
+
+	spin_lock_init(&udc->lock);
+	INIT_WORK(&udc->ep0_wq, bcm63xx_ep0_process);
+	dev_set_name(&udc->gadget.dev, "gadget");
+
+	udc->gadget.ops = &bcm63xx_udc_ops;
+	udc->gadget.name = dev_name(dev);
+	udc->gadget.dev.parent = dev;
+	udc->gadget.dev.release = bcm63xx_udc_gadget_release;
+	udc->gadget.dev.dma_mask = dev->dma_mask;
+
+	if (!pd->use_fullspeed && !use_fullspeed)
+		udc->gadget.max_speed = USB_SPEED_HIGH;
+	else
+		udc->gadget.max_speed = USB_SPEED_FULL;
+
+	/* request clocks, allocate buffers, and clear any pending IRQs */
+	rc = bcm63xx_init_udc_hw(udc);
+	if (rc)
+		return rc;
+
+	rc = -ENXIO;
+
+	/* IRQ resource #0: control interrupt (VBUS, speed, etc.) */
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		dev_err(dev, "missing IRQ resource #0\n");
+		goto out_uninit;
+	}
+	if (devm_request_irq(dev, irq, &bcm63xx_udc_ctrl_isr, 0,
+			     dev_name(dev), udc) < 0) {
+		dev_err(dev, "error requesting IRQ #%d\n", irq);
+		goto out_uninit;
+	}
+
+	/* IRQ resources #1-6: data interrupts for IUDMA channels 0-5 */
+	for (i = 0; i < BCM63XX_NUM_IUDMA; i++) {
+		irq = platform_get_irq(pdev, i + 1);
+		if (irq < 0) {
+			dev_err(dev, "missing IRQ resource #%d\n", i + 1);
+			goto out_uninit;
+		}
+		if (devm_request_irq(dev, irq, &bcm63xx_udc_data_isr, 0,
+				     dev_name(dev), &udc->iudma[i]) < 0) {
+			dev_err(dev, "error requesting IRQ #%d\n", irq);
+			goto out_uninit;
+		}
+	}
+
+	rc = device_register(&udc->gadget.dev);
+	if (rc)
+		goto out_uninit;
+
+	bcm63xx_udc_init_debugfs(udc);
+	rc = usb_add_gadget_udc(dev, &udc->gadget);
+	if (!rc)
+		return 0;
+
+	bcm63xx_udc_cleanup_debugfs(udc);
+	device_unregister(&udc->gadget.dev);
+out_uninit:
+	bcm63xx_uninit_udc_hw(udc);
+	return rc;
+}
+
+/**
+ * bcm63xx_udc_remove - Remove the device from the system.
+ * @pdev: Platform device struct from the bcm63xx BSP code.
+ */
+static int __devexit bcm63xx_udc_remove(struct platform_device *pdev)
+{
+	struct bcm63xx_udc *udc = platform_get_drvdata(pdev);
+
+	bcm63xx_udc_cleanup_debugfs(udc);
+	usb_del_gadget_udc(&udc->gadget);
+	device_unregister(&udc->gadget.dev);
+	BUG_ON(udc->driver);
+
+	platform_set_drvdata(pdev, NULL);
+	bcm63xx_uninit_udc_hw(udc);
+
+	return 0;
+}
+
+static struct platform_driver bcm63xx_udc_driver = {
+	.probe		= bcm63xx_udc_probe,
+	.remove		= __devexit_p(bcm63xx_udc_remove),
+	.driver		= {
+		.name	= DRV_MODULE_NAME,
+		.owner	= THIS_MODULE,
+	},
+};
+module_platform_driver(bcm63xx_udc_driver);
+
+MODULE_DESCRIPTION("BCM63xx USB Peripheral Controller");
+MODULE_AUTHOR("Kevin Cernekee <cernekee@gmail.com>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" DRV_MODULE_NAME);