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 // SPDX-License-Identifier: GPL-2.0+
 /*
  * bcm63xx_udc.c -- BCM63xx UDC high/full speed USB device controller
  *
  * Copyright (C) 2012 Kevin Cernekee <cernekee@gmail.com>
  * Copyright (C) 2012 Broadcom Corporation
  */
 
 #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/interrupt.h>
 #include <linux/ioport.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.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 struct {
     const char *name;
     const struct usb_ep_caps caps;
 } bcm63xx_ep_info[] = {
 #define EP_INFO(_name, _caps) \
     { \
         .name = _name, \
         .caps = _caps, \
     }
 
     EP_INFO(bcm63xx_ep0name,
         USB_EP_CAPS(USB_EP_CAPS_TYPE_CONTROL, USB_EP_CAPS_DIR_ALL)),
     EP_INFO("ep1in-bulk",
         USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_IN)),
     EP_INFO("ep2out-bulk",
         USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_OUT)),
     EP_INFO("ep3in-int",
         USB_EP_CAPS(USB_EP_CAPS_TYPE_INT, USB_EP_CAPS_DIR_IN)),
     EP_INFO("ep4out-int",
         USB_EP_CAPS(USB_EP_CAPS_TYPE_INT, USB_EP_CAPS_DIR_OUT)),
 
 #undef EP_INFO
 };
 
 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 device.
  * @driver: Driver for USB device.
  * @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.
  */
 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;
 };
 
 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, int chan)
 {
     return bcm_readl(udc->iudma_regs + IUDMA_DMAC_OFFSET + off +
             (ENETDMA_CHAN_WIDTH * chan));
 }
 
 static inline void usb_dmac_writel(struct bcm63xx_udc *udc, u32 val, u32 off,
                     int chan)
 {
     bcm_writel(val, udc->iudma_regs + IUDMA_DMAC_OFFSET + off +
             (ENETDMA_CHAN_WIDTH * chan));
 }
 
 static inline u32 usb_dmas_readl(struct bcm63xx_udc *udc, u32 off, int chan)
 {
     return bcm_readl(udc->iudma_regs + IUDMA_DMAS_OFFSET + off +
             (ENETDMA_CHAN_WIDTH * chan));
 }
 
 static inline void usb_dmas_writel(struct bcm63xx_udc *udc, u32 val, u32 off,
                     int chan)
 {
     bcm_writel(val, udc->iudma_regs + IUDMA_DMAS_OFFSET + off +
             (ENETDMA_CHAN_WIDTH * chan));
 }
 
 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;
         usb_ep_set_maxpacket_limit(&udc->bep[idx].ep, 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_info[i].name;
         bep->ep.caps = bcm63xx_ep_info[i].caps;
         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;
         usb_ep_set_maxpacket_limit(&bep->ep, 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 bcm63xx_req *breq, *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_entry_safe(breq, n, &bep->queue, 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);
             usb_gadget_giveback_request(&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 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 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 device.
  * @driver: Driver for USB device.
  */
 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.of_node = udc->dev->of_node;
 
     spin_unlock_irqrestore(&udc->lock, flags);
 
     return 0;
 }
 
 /**
  * bcm63xx_udc_stop - Shut down the controller.
  * @gadget: USB device.
  * @driver: Driver for USB device.
  */
 static int bcm63xx_udc_stop(struct usb_gadget *gadget)
 {
     struct bcm63xx_udc *udc = gadget_to_udc(gadget);
     unsigned long flags;
 
     spin_lock_irqsave(&udc->lock, flags);
 
     udc->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, bus_reset = 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);
         bus_reset = 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);
     else if (bus_reset && udc->driver)
         usb_gadget_udc_reset(&udc->gadget, udc->driver);
 
     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;
 }
 DEFINE_SHOW_ATTRIBUTE(bcm63xx_usbd_dbg);
 
 /*
  * 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;
 }
 DEFINE_SHOW_ATTRIBUTE(bcm63xx_iudma_dbg);
 
 /**
  * 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;
 
     if (!IS_ENABLED(CONFIG_USB_GADGET_DEBUG_FS))
         return;
 
     root = debugfs_create_dir(udc->gadget.name, usb_debug_root);
     debugfs_create_file("usbd", 0400, root, udc, &bcm63xx_usbd_dbg_fops);
     debugfs_create_file("iudma", 0400, root, udc, &bcm63xx_iudma_dbg_fops);
 }
 
 /**
  * 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(debugfs_lookup(udc->gadget.name, usb_debug_root));
 }
 
 /***********************************************************************
  * Driver init/exit
  ***********************************************************************/
 
 /**
  * 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 bcm63xx_udc_probe(struct platform_device *pdev)
 {
     struct device *dev = &pdev->dev;
     struct bcm63xx_usbd_platform_data *pd = dev_get_platdata(dev);
     struct bcm63xx_udc *udc;
     int rc = -ENOMEM, i, irq;
 
     udc = devm_kzalloc(dev, sizeof(*udc), GFP_KERNEL);
     if (!udc)
         return -ENOMEM;
 
     platform_set_drvdata(pdev, udc);
     udc->dev = dev;
     udc->pd = pd;
 
     if (!pd) {
         dev_err(dev, "missing platform data\n");
         return -EINVAL;
     }
 
     udc->usbd_regs = devm_platform_ioremap_resource(pdev, 0);
     if (IS_ERR(udc->usbd_regs))
         return PTR_ERR(udc->usbd_regs);
 
     udc->iudma_regs = devm_platform_ioremap_resource(pdev, 1);
     if (IS_ERR(udc->iudma_regs))
         return PTR_ERR(udc->iudma_regs);
 
     spin_lock_init(&udc->lock);
     INIT_WORK(&udc->ep0_wq, bcm63xx_ep0_process);
 
     udc->gadget.ops = &bcm63xx_udc_ops;
     udc->gadget.name = dev_name(dev);
 
     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) {
         rc = irq;
         goto out_uninit;
     }
     if (devm_request_irq(dev, irq, &bcm63xx_udc_ctrl_isr, 0,
                  dev_name(dev), udc) < 0)
         goto report_request_failure;
 
     /* 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) {
             rc = irq;
             goto out_uninit;
         }
         if (devm_request_irq(dev, irq, &bcm63xx_udc_data_isr, 0,
                      dev_name(dev), &udc->iudma[i]) < 0)
             goto report_request_failure;
     }
 
     bcm63xx_udc_init_debugfs(udc);
     rc = usb_add_gadget_udc(dev, &udc->gadget);
     if (!rc)
         return 0;
 
     bcm63xx_udc_cleanup_debugfs(udc);
 out_uninit:
     bcm63xx_uninit_udc_hw(udc);
     return rc;
 
 report_request_failure:
     dev_err(dev, "error requesting IRQ #%d\n", irq);
     goto out_uninit;
 }
 
 /**
  * bcm63xx_udc_remove - Remove the device from the system.
  * @pdev: Platform device struct from the bcm63xx BSP code.
  */
 static int 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);
     BUG_ON(udc->driver);
 
     bcm63xx_uninit_udc_hw(udc);
 
     return 0;
 }
 
 static struct platform_driver bcm63xx_udc_driver = {
     .probe      = bcm63xx_udc_probe,
     .remove     = bcm63xx_udc_remove,
     .driver     = {
         .name   = DRV_MODULE_NAME,
     },
 };
 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);

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