// SPDX-License-Identifier: GPL-2.0+
/*
 * NVIDIA Tegra XUSB device mode controller
 *
 * Copyright (c) 2013-2019, NVIDIA CORPORATION.  All rights reserved.
 * Copyright (c) 2015, Google Inc.
 */

#include <linux/clk.h>
#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/dmapool.h>
#include <linux/interrupt.h>
#include <linux/iopoll.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/phy/phy.h>
#include <linux/phy/tegra/xusb.h>
#include <linux/pm_domain.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/regulator/consumer.h>
#include <linux/reset.h>
#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>
#include <linux/usb/otg.h>
#include <linux/usb/role.h>
#include <linux/usb/phy.h>
#include <linux/workqueue.h>

/* XUSB_DEV registers */
#define SPARAM 0x000
#define  SPARAM_ERSTMAX_MASK GENMASK(20, 16)
#define  SPARAM_ERSTMAX(x) (((x) << 16) & SPARAM_ERSTMAX_MASK)
#define DB 0x004
#define  DB_TARGET_MASK GENMASK(15, 8)
#define  DB_TARGET(x) (((x) << 8) & DB_TARGET_MASK)
#define  DB_STREAMID_MASK GENMASK(31, 16)
#define  DB_STREAMID(x) (((x) << 16) & DB_STREAMID_MASK)
#define ERSTSZ 0x008
#define  ERSTSZ_ERSTXSZ_SHIFT(x) ((x) * 16)
#define  ERSTSZ_ERSTXSZ_MASK GENMASK(15, 0)
#define ERSTXBALO(x) (0x010 + 8 * (x))
#define ERSTXBAHI(x) (0x014 + 8 * (x))
#define ERDPLO 0x020
#define  ERDPLO_EHB BIT(3)
#define ERDPHI 0x024
#define EREPLO 0x028
#define  EREPLO_ECS BIT(0)
#define  EREPLO_SEGI BIT(1)
#define EREPHI 0x02c
#define CTRL 0x030
#define  CTRL_RUN BIT(0)
#define  CTRL_LSE BIT(1)
#define  CTRL_IE BIT(4)
#define  CTRL_SMI_EVT BIT(5)
#define  CTRL_SMI_DSE BIT(6)
#define  CTRL_EWE BIT(7)
#define  CTRL_DEVADDR_MASK GENMASK(30, 24)
#define  CTRL_DEVADDR(x) (((x) << 24) & CTRL_DEVADDR_MASK)
#define  CTRL_ENABLE BIT(31)
#define ST 0x034
#define  ST_RC BIT(0)
#define  ST_IP BIT(4)
#define RT_IMOD 0x038
#define  RT_IMOD_IMODI_MASK GENMASK(15, 0)
#define  RT_IMOD_IMODI(x) ((x) & RT_IMOD_IMODI_MASK)
#define  RT_IMOD_IMODC_MASK GENMASK(31, 16)
#define  RT_IMOD_IMODC(x) (((x) << 16) & RT_IMOD_IMODC_MASK)
#define PORTSC 0x03c
#define  PORTSC_CCS BIT(0)
#define  PORTSC_PED BIT(1)
#define  PORTSC_PR BIT(4)
#define  PORTSC_PLS_SHIFT 5
#define  PORTSC_PLS_MASK GENMASK(8, 5)
#define  PORTSC_PLS_U0 0x0
#define  PORTSC_PLS_U2 0x2
#define  PORTSC_PLS_U3 0x3
#define  PORTSC_PLS_DISABLED 0x4
#define  PORTSC_PLS_RXDETECT 0x5
#define  PORTSC_PLS_INACTIVE 0x6
#define  PORTSC_PLS_RESUME 0xf
#define  PORTSC_PLS(x) (((x) << PORTSC_PLS_SHIFT) & PORTSC_PLS_MASK)
#define  PORTSC_PS_SHIFT 10
#define  PORTSC_PS_MASK GENMASK(13, 10)
#define  PORTSC_PS_UNDEFINED 0x0
#define  PORTSC_PS_FS 0x1
#define  PORTSC_PS_LS 0x2
#define  PORTSC_PS_HS 0x3
#define  PORTSC_PS_SS 0x4
#define  PORTSC_LWS BIT(16)
#define  PORTSC_CSC BIT(17)
#define  PORTSC_WRC BIT(19)
#define  PORTSC_PRC BIT(21)
#define  PORTSC_PLC BIT(22)
#define  PORTSC_CEC BIT(23)
#define  PORTSC_WPR BIT(30)
#define  PORTSC_CHANGE_MASK (PORTSC_CSC | PORTSC_WRC | PORTSC_PRC | \
                             PORTSC_PLC | PORTSC_CEC)
#define ECPLO 0x040
#define ECPHI 0x044
#define MFINDEX 0x048
#define  MFINDEX_FRAME_SHIFT 3
#define  MFINDEX_FRAME_MASK GENMASK(13, 3)
#define PORTPM 0x04c
#define  PORTPM_L1S_MASK GENMASK(1, 0)
#define  PORTPM_L1S_DROP 0x0
#define  PORTPM_L1S_ACCEPT 0x1
#define  PORTPM_L1S_NYET 0x2
#define  PORTPM_L1S_STALL 0x3
#define  PORTPM_L1S(x) ((x) & PORTPM_L1S_MASK)
#define  PORTPM_RWE BIT(3)
#define  PORTPM_U2TIMEOUT_MASK GENMASK(15, 8)
#define  PORTPM_U1TIMEOUT_MASK GENMASK(23, 16)
#define  PORTPM_FLA BIT(24)
#define  PORTPM_VBA BIT(25)
#define  PORTPM_WOC BIT(26)
#define  PORTPM_WOD BIT(27)
#define  PORTPM_U1E BIT(28)
#define  PORTPM_U2E BIT(29)
#define  PORTPM_FRWE BIT(30)
#define  PORTPM_PNG_CYA BIT(31)
#define EP_HALT 0x050
#define EP_PAUSE 0x054
#define EP_RELOAD 0x058
#define EP_STCHG 0x05c
#define DEVNOTIF_LO 0x064
#define  DEVNOTIF_LO_TRIG BIT(0)
#define  DEVNOTIF_LO_TYPE_MASK GENMASK(7, 4)
#define  DEVNOTIF_LO_TYPE(x) (((x) << 4)  & DEVNOTIF_LO_TYPE_MASK)
#define  DEVNOTIF_LO_TYPE_FUNCTION_WAKE 0x1
#define DEVNOTIF_HI 0x068
#define PORTHALT 0x06c
#define  PORTHALT_HALT_LTSSM BIT(0)
#define  PORTHALT_HALT_REJECT BIT(1)
#define  PORTHALT_STCHG_REQ BIT(20)
#define  PORTHALT_STCHG_INTR_EN BIT(24)
#define PORT_TM 0x070
#define EP_THREAD_ACTIVE 0x074
#define EP_STOPPED 0x078
#define HSFSPI_COUNT0 0x100
#define HSFSPI_COUNT13 0x134
#define  HSFSPI_COUNT13_U2_RESUME_K_DURATION_MASK GENMASK(29, 0)
#define  HSFSPI_COUNT13_U2_RESUME_K_DURATION(x) ((x) & \
                                HSFSPI_COUNT13_U2_RESUME_K_DURATION_MASK)
#define BLCG 0x840
#define SSPX_CORE_CNT0 0x610
#define  SSPX_CORE_CNT0_PING_TBURST_MASK GENMASK(7, 0)
#define  SSPX_CORE_CNT0_PING_TBURST(x) ((x) & SSPX_CORE_CNT0_PING_TBURST_MASK)
#define SSPX_CORE_CNT30 0x688
#define  SSPX_CORE_CNT30_LMPITP_TIMER_MASK GENMASK(19, 0)
#define  SSPX_CORE_CNT30_LMPITP_TIMER(x) ((x) & \
                                        SSPX_CORE_CNT30_LMPITP_TIMER_MASK)
#define SSPX_CORE_CNT32 0x690
#define  SSPX_CORE_CNT32_POLL_TBURST_MAX_MASK GENMASK(7, 0)
#define  SSPX_CORE_CNT32_POLL_TBURST_MAX(x) ((x) & \
                                        SSPX_CORE_CNT32_POLL_TBURST_MAX_MASK)
#define SSPX_CORE_CNT56 0x6fc
#define  SSPX_CORE_CNT56_SCD_BIT0_TRPT_MAX_MASK GENMASK(19, 0)
#define  SSPX_CORE_CNT56_SCD_BIT0_TRPT_MAX(x) ((x) & \
                                SSPX_CORE_CNT56_SCD_BIT0_TRPT_MAX_MASK)
#define SSPX_CORE_CNT57 0x700
#define  SSPX_CORE_CNT57_SCD_BIT1_TRPT_MAX_MASK GENMASK(19, 0)
#define  SSPX_CORE_CNT57_SCD_BIT1_TRPT_MAX(x) ((x) & \
                                SSPX_CORE_CNT57_SCD_BIT1_TRPT_MAX_MASK)
#define SSPX_CORE_CNT65 0x720
#define  SSPX_CORE_CNT65_TX_SCD_END_TRPT_MID_MASK GENMASK(19, 0)
#define  SSPX_CORE_CNT65_TX_SCD_END_TRPT_MID(x) ((x) & \
                                SSPX_CORE_CNT65_TX_SCD_END_TRPT_MID_MASK)
#define SSPX_CORE_CNT66 0x724
#define  SSPX_CORE_CNT66_TX_SCD_BIT0_TRPT_MID_MASK GENMASK(19, 0)
#define  SSPX_CORE_CNT66_TX_SCD_BIT0_TRPT_MID(x) ((x) & \
                                SSPX_CORE_CNT66_TX_SCD_BIT0_TRPT_MID_MASK)
#define SSPX_CORE_CNT67 0x728
#define  SSPX_CORE_CNT67_TX_SCD_BIT1_TRPT_MID_MASK GENMASK(19, 0)
#define  SSPX_CORE_CNT67_TX_SCD_BIT1_TRPT_MID(x) ((x) & \
                                SSPX_CORE_CNT67_TX_SCD_BIT1_TRPT_MID_MASK)
#define SSPX_CORE_CNT72 0x73c
#define  SSPX_CORE_CNT72_SCD_LFPS_TIMEOUT_MASK GENMASK(19, 0)
#define  SSPX_CORE_CNT72_SCD_LFPS_TIMEOUT(x) ((x) & \
                                SSPX_CORE_CNT72_SCD_LFPS_TIMEOUT_MASK)
#define SSPX_CORE_PADCTL4 0x750
#define  SSPX_CORE_PADCTL4_RXDAT_VLD_TIMEOUT_U3_MASK GENMASK(19, 0)
#define  SSPX_CORE_PADCTL4_RXDAT_VLD_TIMEOUT_U3(x) ((x) & \
                                SSPX_CORE_PADCTL4_RXDAT_VLD_TIMEOUT_U3_MASK)
#define  BLCG_DFPCI BIT(0)
#define  BLCG_UFPCI BIT(1)
#define  BLCG_FE BIT(2)
#define  BLCG_COREPLL_PWRDN BIT(8)
#define  BLCG_IOPLL_0_PWRDN BIT(9)
#define  BLCG_IOPLL_1_PWRDN BIT(10)
#define  BLCG_IOPLL_2_PWRDN BIT(11)
#define  BLCG_ALL 0x1ff
#define CFG_DEV_SSPI_XFER 0x858
#define  CFG_DEV_SSPI_XFER_ACKTIMEOUT_MASK GENMASK(31, 0)
#define  CFG_DEV_SSPI_XFER_ACKTIMEOUT(x) ((x) & \
                                        CFG_DEV_SSPI_XFER_ACKTIMEOUT_MASK)
#define CFG_DEV_FE 0x85c
#define  CFG_DEV_FE_PORTREGSEL_MASK GENMASK(1, 0)
#define  CFG_DEV_FE_PORTREGSEL_SS_PI 1
#define  CFG_DEV_FE_PORTREGSEL_HSFS_PI 2
#define  CFG_DEV_FE_PORTREGSEL(x) ((x) & CFG_DEV_FE_PORTREGSEL_MASK)
#define  CFG_DEV_FE_INFINITE_SS_RETRY BIT(29)

/* FPCI registers */
#define XUSB_DEV_CFG_1 0x004
#define  XUSB_DEV_CFG_1_IO_SPACE_EN BIT(0)
#define  XUSB_DEV_CFG_1_MEMORY_SPACE_EN BIT(1)
#define  XUSB_DEV_CFG_1_BUS_MASTER_EN BIT(2)
#define XUSB_DEV_CFG_4 0x010
#define  XUSB_DEV_CFG_4_BASE_ADDR_MASK GENMASK(31, 15)
#define XUSB_DEV_CFG_5 0x014

/* IPFS registers */
#define XUSB_DEV_CONFIGURATION_0 0x180
#define  XUSB_DEV_CONFIGURATION_0_EN_FPCI BIT(0)
#define XUSB_DEV_INTR_MASK_0 0x188
#define  XUSB_DEV_INTR_MASK_0_IP_INT_MASK BIT(16)

struct tegra_xudc_ep_context {
        __le32 info0;
        __le32 info1;
        __le32 deq_lo;
        __le32 deq_hi;
        __le32 tx_info;
        __le32 rsvd[11];
};

#define EP_STATE_DISABLED 0
#define EP_STATE_RUNNING 1
#define EP_STATE_HALTED 2
#define EP_STATE_STOPPED 3
#define EP_STATE_ERROR 4

#define EP_TYPE_INVALID 0
#define EP_TYPE_ISOCH_OUT 1
#define EP_TYPE_BULK_OUT 2
#define EP_TYPE_INTERRUPT_OUT 3
#define EP_TYPE_CONTROL 4
#define EP_TYPE_ISCOH_IN 5
#define EP_TYPE_BULK_IN 6
#define EP_TYPE_INTERRUPT_IN 7

#define BUILD_EP_CONTEXT_RW(name, member, shift, mask)                  \
static inline u32 ep_ctx_read_##name(struct tegra_xudc_ep_context *ctx) \
{                                                                       \
        return (le32_to_cpu(ctx->member) >> (shift)) & (mask);          \
}                                                                       \
static inline void                                                      \
ep_ctx_write_##name(struct tegra_xudc_ep_context *ctx, u32 val)         \
{                                                                       \
        u32 tmp;                                                        \
                                                                        \
        tmp = le32_to_cpu(ctx->member) & ~((mask) << (shift));          \
        tmp |= (val & (mask)) << (shift);                               \
        ctx->member = cpu_to_le32(tmp);                                 \
}

BUILD_EP_CONTEXT_RW(state, info0, 0, 0x7)
BUILD_EP_CONTEXT_RW(mult, info0, 8, 0x3)
BUILD_EP_CONTEXT_RW(max_pstreams, info0, 10, 0x1f)
BUILD_EP_CONTEXT_RW(lsa, info0, 15, 0x1)
BUILD_EP_CONTEXT_RW(interval, info0, 16, 0xff)
BUILD_EP_CONTEXT_RW(cerr, info1, 1, 0x3)
BUILD_EP_CONTEXT_RW(type, info1, 3, 0x7)
BUILD_EP_CONTEXT_RW(hid, info1, 7, 0x1)
BUILD_EP_CONTEXT_RW(max_burst_size, info1, 8, 0xff)
BUILD_EP_CONTEXT_RW(max_packet_size, info1, 16, 0xffff)
BUILD_EP_CONTEXT_RW(dcs, deq_lo, 0, 0x1)
BUILD_EP_CONTEXT_RW(deq_lo, deq_lo, 4, 0xfffffff)
BUILD_EP_CONTEXT_RW(deq_hi, deq_hi, 0, 0xffffffff)
BUILD_EP_CONTEXT_RW(avg_trb_len, tx_info, 0, 0xffff)
BUILD_EP_CONTEXT_RW(max_esit_payload, tx_info, 16, 0xffff)
BUILD_EP_CONTEXT_RW(edtla, rsvd[0], 0, 0xffffff)
BUILD_EP_CONTEXT_RW(seq_num, rsvd[0], 24, 0xff)
BUILD_EP_CONTEXT_RW(partial_td, rsvd[0], 25, 0x1)
BUILD_EP_CONTEXT_RW(cerrcnt, rsvd[1], 18, 0x3)
BUILD_EP_CONTEXT_RW(data_offset, rsvd[2], 0, 0x1ffff)
BUILD_EP_CONTEXT_RW(numtrbs, rsvd[2], 22, 0x1f)
BUILD_EP_CONTEXT_RW(devaddr, rsvd[6], 0, 0x7f)

static inline u64 ep_ctx_read_deq_ptr(struct tegra_xudc_ep_context *ctx)
{
        return ((u64)ep_ctx_read_deq_hi(ctx) << 32) |
                (ep_ctx_read_deq_lo(ctx) << 4);
}

static inline void
ep_ctx_write_deq_ptr(struct tegra_xudc_ep_context *ctx, u64 addr)
{
        ep_ctx_write_deq_lo(ctx, lower_32_bits(addr) >> 4);
        ep_ctx_write_deq_hi(ctx, upper_32_bits(addr));
}

struct tegra_xudc_trb {
        __le32 data_lo;
        __le32 data_hi;
        __le32 status;
        __le32 control;
};

#define TRB_TYPE_RSVD 0
#define TRB_TYPE_NORMAL 1
#define TRB_TYPE_SETUP_STAGE 2
#define TRB_TYPE_DATA_STAGE 3
#define TRB_TYPE_STATUS_STAGE 4
#define TRB_TYPE_ISOCH 5
#define TRB_TYPE_LINK 6
#define TRB_TYPE_TRANSFER_EVENT 32
#define TRB_TYPE_PORT_STATUS_CHANGE_EVENT 34
#define TRB_TYPE_STREAM 48
#define TRB_TYPE_SETUP_PACKET_EVENT 63

#define TRB_CMPL_CODE_INVALID 0
#define TRB_CMPL_CODE_SUCCESS 1
#define TRB_CMPL_CODE_DATA_BUFFER_ERR 2
#define TRB_CMPL_CODE_BABBLE_DETECTED_ERR 3
#define TRB_CMPL_CODE_USB_TRANS_ERR 4
#define TRB_CMPL_CODE_TRB_ERR 5
#define TRB_CMPL_CODE_STALL 6
#define TRB_CMPL_CODE_INVALID_STREAM_TYPE_ERR 10
#define TRB_CMPL_CODE_SHORT_PACKET 13
#define TRB_CMPL_CODE_RING_UNDERRUN 14
#define TRB_CMPL_CODE_RING_OVERRUN 15
#define TRB_CMPL_CODE_EVENT_RING_FULL_ERR 21
#define TRB_CMPL_CODE_STOPPED 26
#define TRB_CMPL_CODE_ISOCH_BUFFER_OVERRUN 31
#define TRB_CMPL_CODE_STREAM_NUMP_ERROR 219
#define TRB_CMPL_CODE_PRIME_PIPE_RECEIVED 220
#define TRB_CMPL_CODE_HOST_REJECTED 221
#define TRB_CMPL_CODE_CTRL_DIR_ERR 222
#define TRB_CMPL_CODE_CTRL_SEQNUM_ERR 223

#define BUILD_TRB_RW(name, member, shift, mask)                         \
static inline u32 trb_read_##name(struct tegra_xudc_trb *trb)           \
{                                                                       \
        return (le32_to_cpu(trb->member) >> (shift)) & (mask);          \
}                                                                       \
static inline void                                                      \
trb_write_##name(struct tegra_xudc_trb *trb, u32 val)                   \
{                                                                       \
        u32 tmp;                                                        \
                                                                        \
        tmp = le32_to_cpu(trb->member) & ~((mask) << (shift));          \
        tmp |= (val & (mask)) << (shift);                               \
        trb->member = cpu_to_le32(tmp);                                 \
}

BUILD_TRB_RW(data_lo, data_lo, 0, 0xffffffff)
BUILD_TRB_RW(data_hi, data_hi, 0, 0xffffffff)
BUILD_TRB_RW(seq_num, status, 0, 0xffff)
BUILD_TRB_RW(transfer_len, status, 0, 0xffffff)
BUILD_TRB_RW(td_size, status, 17, 0x1f)
BUILD_TRB_RW(cmpl_code, status, 24, 0xff)
BUILD_TRB_RW(cycle, control, 0, 0x1)
BUILD_TRB_RW(toggle_cycle, control, 1, 0x1)
BUILD_TRB_RW(isp, control, 2, 0x1)
BUILD_TRB_RW(chain, control, 4, 0x1)
BUILD_TRB_RW(ioc, control, 5, 0x1)
BUILD_TRB_RW(type, control, 10, 0x3f)
BUILD_TRB_RW(stream_id, control, 16, 0xffff)
BUILD_TRB_RW(endpoint_id, control, 16, 0x1f)
BUILD_TRB_RW(tlbpc, control, 16, 0xf)
BUILD_TRB_RW(data_stage_dir, control, 16, 0x1)
BUILD_TRB_RW(frame_id, control, 20, 0x7ff)
BUILD_TRB_RW(sia, control, 31, 0x1)

static inline u64 trb_read_data_ptr(struct tegra_xudc_trb *trb)
{
        return ((u64)trb_read_data_hi(trb) << 32) |
                trb_read_data_lo(trb);
}

static inline void trb_write_data_ptr(struct tegra_xudc_trb *trb, u64 addr)
{
        trb_write_data_lo(trb, lower_32_bits(addr));
        trb_write_data_hi(trb, upper_32_bits(addr));
}

struct tegra_xudc_request {
        struct usb_request usb_req;

        size_t buf_queued;
        unsigned int trbs_queued;
        unsigned int trbs_needed;
        bool need_zlp;

        struct tegra_xudc_trb *first_trb;
        struct tegra_xudc_trb *last_trb;

        struct list_head list;
};

struct tegra_xudc_ep {
        struct tegra_xudc *xudc;
        struct usb_ep usb_ep;
        unsigned int index;
        char name[8];

        struct tegra_xudc_ep_context *context;

#define XUDC_TRANSFER_RING_SIZE 64
        struct tegra_xudc_trb *transfer_ring;
        dma_addr_t transfer_ring_phys;

        unsigned int enq_ptr;
        unsigned int deq_ptr;
        bool pcs;
        bool ring_full;
        bool stream_rejected;

        struct list_head queue;
        const struct usb_endpoint_descriptor *desc;
        const struct usb_ss_ep_comp_descriptor *comp_desc;
};

struct tegra_xudc_sel_timing {
        __u8 u1sel;
        __u8 u1pel;
        __le16 u2sel;
        __le16 u2pel;
};

enum tegra_xudc_setup_state {
        WAIT_FOR_SETUP,
        DATA_STAGE_XFER,
        DATA_STAGE_RECV,
        STATUS_STAGE_XFER,
        STATUS_STAGE_RECV,
};

struct tegra_xudc_setup_packet {
        struct usb_ctrlrequest ctrl_req;
        unsigned int seq_num;
};

struct tegra_xudc_save_regs {
        u32 ctrl;
        u32 portpm;
};

struct tegra_xudc {
        struct device *dev;
        const struct tegra_xudc_soc *soc;
        struct tegra_xusb_padctl *padctl;

        spinlock_t lock;

        struct usb_gadget gadget;
        struct usb_gadget_driver *driver;

#define XUDC_NR_EVENT_RINGS 2
#define XUDC_EVENT_RING_SIZE 4096
        struct tegra_xudc_trb *event_ring[XUDC_NR_EVENT_RINGS];
        dma_addr_t event_ring_phys[XUDC_NR_EVENT_RINGS];
        unsigned int event_ring_index;
        unsigned int event_ring_deq_ptr;
        bool ccs;

#define XUDC_NR_EPS 32
        struct tegra_xudc_ep ep[XUDC_NR_EPS];
        struct tegra_xudc_ep_context *ep_context;
        dma_addr_t ep_context_phys;

        struct device *genpd_dev_device;
        struct device *genpd_dev_ss;
        struct device_link *genpd_dl_device;
        struct device_link *genpd_dl_ss;

        struct dma_pool *transfer_ring_pool;

        bool queued_setup_packet;
        struct tegra_xudc_setup_packet setup_packet;
        enum tegra_xudc_setup_state setup_state;
        u16 setup_seq_num;

        u16 dev_addr;
        u16 isoch_delay;
        struct tegra_xudc_sel_timing sel_timing;
        u8 test_mode_pattern;
        u16 status_buf;
        struct tegra_xudc_request *ep0_req;

        bool pullup;

        unsigned int nr_enabled_eps;
        unsigned int nr_isoch_eps;

        unsigned int device_state;
        unsigned int resume_state;

        int irq;

        void __iomem *base;
        resource_size_t phys_base;
        void __iomem *ipfs;
        void __iomem *fpci;

        struct regulator_bulk_data *supplies;

        struct clk_bulk_data *clks;

        bool device_mode;
        struct work_struct usb_role_sw_work;

        struct phy **usb3_phy;
        struct phy *curr_usb3_phy;
        struct phy **utmi_phy;
        struct phy *curr_utmi_phy;

        struct tegra_xudc_save_regs saved_regs;
        bool suspended;
        bool powergated;

        struct usb_phy **usbphy;
        struct usb_phy *curr_usbphy;
        struct notifier_block vbus_nb;

        struct completion disconnect_complete;

        bool selfpowered;

#define TOGGLE_VBUS_WAIT_MS 100
        struct delayed_work plc_reset_work;
        bool wait_csc;

        struct delayed_work port_reset_war_work;
        bool wait_for_sec_prc;
};

#define XUDC_TRB_MAX_BUFFER_SIZE 65536
#define XUDC_MAX_ISOCH_EPS 4
#define XUDC_INTERRUPT_MODERATION_US 0

static struct usb_endpoint_descriptor tegra_xudc_ep0_desc = {
        .bLength = USB_DT_ENDPOINT_SIZE,
        .bDescriptorType = USB_DT_ENDPOINT,
        .bEndpointAddress = 0,
        .bmAttributes = USB_ENDPOINT_XFER_CONTROL,
        .wMaxPacketSize = cpu_to_le16(64),
};

struct tegra_xudc_soc {
        const char * const *supply_names;
        unsigned int num_supplies;
        const char * const *clock_names;
        unsigned int num_clks;
        unsigned int num_phys;
        bool u1_enable;
        bool u2_enable;
        bool lpm_enable;
        bool invalid_seq_num;
        bool pls_quirk;
        bool port_reset_quirk;
        bool port_speed_quirk;
        bool has_ipfs;
};

static inline u32 fpci_readl(struct tegra_xudc *xudc, unsigned int offset)
{
        return readl(xudc->fpci + offset);
}

static inline void fpci_writel(struct tegra_xudc *xudc, u32 val,
                               unsigned int offset)
{
        writel(val, xudc->fpci + offset);
}

static inline u32 ipfs_readl(struct tegra_xudc *xudc, unsigned int offset)
{
        return readl(xudc->ipfs + offset);
}

static inline void ipfs_writel(struct tegra_xudc *xudc, u32 val,
                               unsigned int offset)
{
        writel(val, xudc->ipfs + offset);
}

static inline u32 xudc_readl(struct tegra_xudc *xudc, unsigned int offset)
{
        return readl(xudc->base + offset);
}

static inline void xudc_writel(struct tegra_xudc *xudc, u32 val,
                               unsigned int offset)
{
        writel(val, xudc->base + offset);
}

static inline int xudc_readl_poll(struct tegra_xudc *xudc,
                                  unsigned int offset, u32 mask, u32 val)
{
        u32 regval;

        return readl_poll_timeout_atomic(xudc->base + offset, regval,
                                         (regval & mask) == val, 1, 100);
}

static inline struct tegra_xudc *to_xudc(struct usb_gadget *gadget)
{
        return container_of(gadget, struct tegra_xudc, gadget);
}

static inline struct tegra_xudc_ep *to_xudc_ep(struct usb_ep *ep)
{
        return container_of(ep, struct tegra_xudc_ep, usb_ep);
}

static inline struct tegra_xudc_request *to_xudc_req(struct usb_request *req)
{
        return container_of(req, struct tegra_xudc_request, usb_req);
}

static inline void dump_trb(struct tegra_xudc *xudc, const char *type,
                            struct tegra_xudc_trb *trb)
{
        dev_dbg(xudc->dev,
                "%s: %p, lo = %#x, hi = %#x, status = %#x, control = %#x\n",
                type, trb, trb->data_lo, trb->data_hi, trb->status,
                trb->control);
}

static void tegra_xudc_limit_port_speed(struct tegra_xudc *xudc)
{
        u32 val;

        /* limit port speed to gen 1 */
        val = xudc_readl(xudc, SSPX_CORE_CNT56);
        val &= ~(SSPX_CORE_CNT56_SCD_BIT0_TRPT_MAX_MASK);
        val |= SSPX_CORE_CNT56_SCD_BIT0_TRPT_MAX(0x260);
        xudc_writel(xudc, val, SSPX_CORE_CNT56);

        val = xudc_readl(xudc, SSPX_CORE_CNT57);
        val &= ~(SSPX_CORE_CNT57_SCD_BIT1_TRPT_MAX_MASK);
        val |= SSPX_CORE_CNT57_SCD_BIT1_TRPT_MAX(0x6D6);
        xudc_writel(xudc, val, SSPX_CORE_CNT57);

        val = xudc_readl(xudc, SSPX_CORE_CNT65);
        val &= ~(SSPX_CORE_CNT65_TX_SCD_END_TRPT_MID_MASK);
        val |= SSPX_CORE_CNT65_TX_SCD_END_TRPT_MID(0x4B0);
        xudc_writel(xudc, val, SSPX_CORE_CNT66);

        val = xudc_readl(xudc, SSPX_CORE_CNT66);
        val &= ~(SSPX_CORE_CNT66_TX_SCD_BIT0_TRPT_MID_MASK);
        val |= SSPX_CORE_CNT66_TX_SCD_BIT0_TRPT_MID(0x4B0);
        xudc_writel(xudc, val, SSPX_CORE_CNT66);

        val = xudc_readl(xudc, SSPX_CORE_CNT67);
        val &= ~(SSPX_CORE_CNT67_TX_SCD_BIT1_TRPT_MID_MASK);
        val |= SSPX_CORE_CNT67_TX_SCD_BIT1_TRPT_MID(0x4B0);
        xudc_writel(xudc, val, SSPX_CORE_CNT67);

        val = xudc_readl(xudc, SSPX_CORE_CNT72);
        val &= ~(SSPX_CORE_CNT72_SCD_LFPS_TIMEOUT_MASK);
        val |= SSPX_CORE_CNT72_SCD_LFPS_TIMEOUT(0x10);
        xudc_writel(xudc, val, SSPX_CORE_CNT72);
}

static void tegra_xudc_restore_port_speed(struct tegra_xudc *xudc)
{
        u32 val;

        /* restore port speed to gen2 */
        val = xudc_readl(xudc, SSPX_CORE_CNT56);
        val &= ~(SSPX_CORE_CNT56_SCD_BIT0_TRPT_MAX_MASK);
        val |= SSPX_CORE_CNT56_SCD_BIT0_TRPT_MAX(0x438);
        xudc_writel(xudc, val, SSPX_CORE_CNT56);

        val = xudc_readl(xudc, SSPX_CORE_CNT57);
        val &= ~(SSPX_CORE_CNT57_SCD_BIT1_TRPT_MAX_MASK);
        val |= SSPX_CORE_CNT57_SCD_BIT1_TRPT_MAX(0x528);
        xudc_writel(xudc, val, SSPX_CORE_CNT57);

        val = xudc_readl(xudc, SSPX_CORE_CNT65);
        val &= ~(SSPX_CORE_CNT65_TX_SCD_END_TRPT_MID_MASK);
        val |= SSPX_CORE_CNT65_TX_SCD_END_TRPT_MID(0xE10);
        xudc_writel(xudc, val, SSPX_CORE_CNT66);

        val = xudc_readl(xudc, SSPX_CORE_CNT66);
        val &= ~(SSPX_CORE_CNT66_TX_SCD_BIT0_TRPT_MID_MASK);
        val |= SSPX_CORE_CNT66_TX_SCD_BIT0_TRPT_MID(0x348);
        xudc_writel(xudc, val, SSPX_CORE_CNT66);

        val = xudc_readl(xudc, SSPX_CORE_CNT67);
        val &= ~(SSPX_CORE_CNT67_TX_SCD_BIT1_TRPT_MID_MASK);
        val |= SSPX_CORE_CNT67_TX_SCD_BIT1_TRPT_MID(0x5a0);
        xudc_writel(xudc, val, SSPX_CORE_CNT67);

        val = xudc_readl(xudc, SSPX_CORE_CNT72);
        val &= ~(SSPX_CORE_CNT72_SCD_LFPS_TIMEOUT_MASK);
        val |= SSPX_CORE_CNT72_SCD_LFPS_TIMEOUT(0x1c21);
        xudc_writel(xudc, val, SSPX_CORE_CNT72);
}

static void tegra_xudc_device_mode_on(struct tegra_xudc *xudc)
{
        int err;

        pm_runtime_get_sync(xudc->dev);

        err = phy_power_on(xudc->curr_utmi_phy);
        if (err < 0)
                dev_err(xudc->dev, "UTMI power on failed: %d\n", err);

        err = phy_power_on(xudc->curr_usb3_phy);
        if (err < 0)
                dev_err(xudc->dev, "USB3 PHY power on failed: %d\n", err);

        dev_dbg(xudc->dev, "device mode on\n");

        phy_set_mode_ext(xudc->curr_utmi_phy, PHY_MODE_USB_OTG,
                         USB_ROLE_DEVICE);
}

static void tegra_xudc_device_mode_off(struct tegra_xudc *xudc)
{
        bool connected = false;
        u32 pls, val;
        int err;

        dev_dbg(xudc->dev, "device mode off\n");

        connected = !!(xudc_readl(xudc, PORTSC) & PORTSC_CCS);

        reinit_completion(&xudc->disconnect_complete);

        if (xudc->soc->port_speed_quirk)
                tegra_xudc_restore_port_speed(xudc);

        phy_set_mode_ext(xudc->curr_utmi_phy, PHY_MODE_USB_OTG, USB_ROLE_NONE);

        pls = (xudc_readl(xudc, PORTSC) & PORTSC_PLS_MASK) >>
                PORTSC_PLS_SHIFT;

        /* Direct link to U0 if disconnected in RESUME or U2. */
        if (xudc->soc->pls_quirk && xudc->gadget.speed == USB_SPEED_SUPER &&
            (pls == PORTSC_PLS_RESUME || pls == PORTSC_PLS_U2)) {
                val = xudc_readl(xudc, PORTPM);
                val |= PORTPM_FRWE;
                xudc_writel(xudc, val, PORTPM);

                val = xudc_readl(xudc, PORTSC);
                val &= ~(PORTSC_CHANGE_MASK | PORTSC_PLS_MASK);
                val |= PORTSC_LWS | PORTSC_PLS(PORTSC_PLS_U0);
                xudc_writel(xudc, val, PORTSC);
        }

        /* Wait for disconnect event. */
        if (connected)
                wait_for_completion(&xudc->disconnect_complete);

        /* Make sure interrupt handler has completed before powergating. */
        synchronize_irq(xudc->irq);

        err = phy_power_off(xudc->curr_utmi_phy);
        if (err < 0)
                dev_err(xudc->dev, "UTMI PHY power off failed: %d\n", err);

        err = phy_power_off(xudc->curr_usb3_phy);
        if (err < 0)
                dev_err(xudc->dev, "USB3 PHY power off failed: %d\n", err);

        pm_runtime_put(xudc->dev);
}

static void tegra_xudc_usb_role_sw_work(struct work_struct *work)
{
        struct tegra_xudc *xudc = container_of(work, struct tegra_xudc,
                                               usb_role_sw_work);

        if (xudc->device_mode)
                tegra_xudc_device_mode_on(xudc);
        else
                tegra_xudc_device_mode_off(xudc);
}

static int tegra_xudc_get_phy_index(struct tegra_xudc *xudc,
                                              struct usb_phy *usbphy)
{
        unsigned int i;

        for (i = 0; i < xudc->soc->num_phys; i++) {
                if (xudc->usbphy[i] && usbphy == xudc->usbphy[i])
                        return i;
        }

        dev_info(xudc->dev, "phy index could not be found for shared USB PHY");
        return -1;
}

static int tegra_xudc_vbus_notify(struct notifier_block *nb,
                                         unsigned long action, void *data)
{
        struct tegra_xudc *xudc = container_of(nb, struct tegra_xudc,
                                               vbus_nb);
        struct usb_phy *usbphy = (struct usb_phy *)data;
        int phy_index;

        dev_dbg(xudc->dev, "%s(): event is %d\n", __func__, usbphy->last_event);

        if ((xudc->device_mode && usbphy->last_event == USB_EVENT_VBUS) ||
            (!xudc->device_mode && usbphy->last_event != USB_EVENT_VBUS)) {
                dev_dbg(xudc->dev, "Same role(%d) received. Ignore",
                        xudc->device_mode);
                return NOTIFY_OK;
        }

        xudc->device_mode = (usbphy->last_event == USB_EVENT_VBUS) ? true :
                                                                     false;

        phy_index = tegra_xudc_get_phy_index(xudc, usbphy);
        dev_dbg(xudc->dev, "%s(): current phy index is %d\n", __func__,
                phy_index);

        if (!xudc->suspended && phy_index != -1) {
                xudc->curr_utmi_phy = xudc->utmi_phy[phy_index];
                xudc->curr_usb3_phy = xudc->usb3_phy[phy_index];
                xudc->curr_usbphy = usbphy;
                schedule_work(&xudc->usb_role_sw_work);
        }

        return NOTIFY_OK;
}

static void tegra_xudc_plc_reset_work(struct work_struct *work)
{
        struct delayed_work *dwork = to_delayed_work(work);
        struct tegra_xudc *xudc = container_of(dwork, struct tegra_xudc,
                                               plc_reset_work);
        unsigned long flags;

        spin_lock_irqsave(&xudc->lock, flags);

        if (xudc->wait_csc) {
                u32 pls = (xudc_readl(xudc, PORTSC) & PORTSC_PLS_MASK) >>
                        PORTSC_PLS_SHIFT;

                if (pls == PORTSC_PLS_INACTIVE) {
                        dev_info(xudc->dev, "PLS = Inactive. Toggle VBUS\n");
                        phy_set_mode_ext(xudc->curr_utmi_phy, PHY_MODE_USB_OTG,
                                         USB_ROLE_NONE);
                        phy_set_mode_ext(xudc->curr_utmi_phy, PHY_MODE_USB_OTG,
                                         USB_ROLE_DEVICE);

                        xudc->wait_csc = false;
                }
        }

        spin_unlock_irqrestore(&xudc->lock, flags);
}

static void tegra_xudc_port_reset_war_work(struct work_struct *work)
{
        struct delayed_work *dwork = to_delayed_work(work);
        struct tegra_xudc *xudc =
                container_of(dwork, struct tegra_xudc, port_reset_war_work);
        unsigned long flags;
        u32 pls;
        int ret;

        spin_lock_irqsave(&xudc->lock, flags);

        if (xudc->device_mode && xudc->wait_for_sec_prc) {
                pls = (xudc_readl(xudc, PORTSC) & PORTSC_PLS_MASK) >>
                        PORTSC_PLS_SHIFT;
                dev_dbg(xudc->dev, "pls = %x\n", pls);

                if (pls == PORTSC_PLS_DISABLED) {
                        dev_dbg(xudc->dev, "toggle vbus\n");
                        /* PRC doesn't complete in 100ms, toggle the vbus */
                        ret = tegra_phy_xusb_utmi_port_reset(
                                xudc->curr_utmi_phy);
                        if (ret == 1)
                                xudc->wait_for_sec_prc = 0;
                }
        }

        spin_unlock_irqrestore(&xudc->lock, flags);
}

static dma_addr_t trb_virt_to_phys(struct tegra_xudc_ep *ep,
                                   struct tegra_xudc_trb *trb)
{
        unsigned int index;

        index = trb - ep->transfer_ring;

        if (WARN_ON(index >= XUDC_TRANSFER_RING_SIZE))
                return 0;

        return (ep->transfer_ring_phys + index * sizeof(*trb));
}

static struct tegra_xudc_trb *trb_phys_to_virt(struct tegra_xudc_ep *ep,
                                               dma_addr_t addr)
{
        struct tegra_xudc_trb *trb;
        unsigned int index;

        index = (addr - ep->transfer_ring_phys) / sizeof(*trb);

        if (WARN_ON(index >= XUDC_TRANSFER_RING_SIZE))
                return NULL;

        trb = &ep->transfer_ring[index];

        return trb;
}

static void ep_reload(struct tegra_xudc *xudc, unsigned int ep)
{
        xudc_writel(xudc, BIT(ep), EP_RELOAD);
        xudc_readl_poll(xudc, EP_RELOAD, BIT(ep), 0);
}

static void ep_pause(struct tegra_xudc *xudc, unsigned int ep)
{
        u32 val;

        val = xudc_readl(xudc, EP_PAUSE);
        if (val & BIT(ep))
                return;
        val |= BIT(ep);

        xudc_writel(xudc, val, EP_PAUSE);

        xudc_readl_poll(xudc, EP_STCHG, BIT(ep), BIT(ep));

        xudc_writel(xudc, BIT(ep), EP_STCHG);
}

static void ep_unpause(struct tegra_xudc *xudc, unsigned int ep)
{
        u32 val;

        val = xudc_readl(xudc, EP_PAUSE);
        if (!(val & BIT(ep)))
                return;
        val &= ~BIT(ep);

        xudc_writel(xudc, val, EP_PAUSE);

        xudc_readl_poll(xudc, EP_STCHG, BIT(ep), BIT(ep));

        xudc_writel(xudc, BIT(ep), EP_STCHG);
}

static void ep_unpause_all(struct tegra_xudc *xudc)
{
        u32 val;

        val = xudc_readl(xudc, EP_PAUSE);

        xudc_writel(xudc, 0, EP_PAUSE);

        xudc_readl_poll(xudc, EP_STCHG, val, val);

        xudc_writel(xudc, val, EP_STCHG);
}

static void ep_halt(struct tegra_xudc *xudc, unsigned int ep)
{
        u32 val;

        val = xudc_readl(xudc, EP_HALT);
        if (val & BIT(ep))
                return;
        val |= BIT(ep);
        xudc_writel(xudc, val, EP_HALT);

        xudc_readl_poll(xudc, EP_STCHG, BIT(ep), BIT(ep));

        xudc_writel(xudc, BIT(ep), EP_STCHG);
}

static void ep_unhalt(struct tegra_xudc *xudc, unsigned int ep)
{
        u32 val;

        val = xudc_readl(xudc, EP_HALT);
        if (!(val & BIT(ep)))
                return;
        val &= ~BIT(ep);
        xudc_writel(xudc, val, EP_HALT);

        xudc_readl_poll(xudc, EP_STCHG, BIT(ep), BIT(ep));

        xudc_writel(xudc, BIT(ep), EP_STCHG);
}

static void ep_unhalt_all(struct tegra_xudc *xudc)
{
        u32 val;

        val = xudc_readl(xudc, EP_HALT);

        if (!val)
                return;
        xudc_writel(xudc, 0, EP_HALT);

        xudc_readl_poll(xudc, EP_STCHG, val, val);

        xudc_writel(xudc, val, EP_STCHG);
}

static void ep_wait_for_stopped(struct tegra_xudc *xudc, unsigned int ep)
{
        xudc_readl_poll(xudc, EP_STOPPED, BIT(ep), BIT(ep));
        xudc_writel(xudc, BIT(ep), EP_STOPPED);
}

static void ep_wait_for_inactive(struct tegra_xudc *xudc, unsigned int ep)
{
        xudc_readl_poll(xudc, EP_THREAD_ACTIVE, BIT(ep), 0);
}

static void tegra_xudc_req_done(struct tegra_xudc_ep *ep,
                                struct tegra_xudc_request *req, int status)
{
        struct tegra_xudc *xudc = ep->xudc;

        dev_dbg(xudc->dev, "completing request %p on EP %u with status %d\n",
                 req, ep->index, status);

        if (likely(req->usb_req.status == -EINPROGRESS))
                req->usb_req.status = status;

        list_del_init(&req->list);

        if (usb_endpoint_xfer_control(ep->desc)) {
                usb_gadget_unmap_request(&xudc->gadget, &req->usb_req,
                                         (xudc->setup_state ==
                                          DATA_STAGE_XFER));
        } else {
                usb_gadget_unmap_request(&xudc->gadget, &req->usb_req,
                                         usb_endpoint_dir_in(ep->desc));
        }

        spin_unlock(&xudc->lock);
        usb_gadget_giveback_request(&ep->usb_ep, &req->usb_req);
        spin_lock(&xudc->lock);
}

static void tegra_xudc_ep_nuke(struct tegra_xudc_ep *ep, int status)
{
        struct tegra_xudc_request *req;

        while (!list_empty(&ep->queue)) {
                req = list_first_entry(&ep->queue, struct tegra_xudc_request,
                                       list);
                tegra_xudc_req_done(ep, req, status);
        }
}

static unsigned int ep_available_trbs(struct tegra_xudc_ep *ep)
{
        if (ep->ring_full)
                return 0;

        if (ep->deq_ptr > ep->enq_ptr)
                return ep->deq_ptr - ep->enq_ptr - 1;

        return XUDC_TRANSFER_RING_SIZE - (ep->enq_ptr - ep->deq_ptr) - 2;
}

static void tegra_xudc_queue_one_trb(struct tegra_xudc_ep *ep,
                                     struct tegra_xudc_request *req,
                                     struct tegra_xudc_trb *trb,
                                     bool ioc)
{
        struct tegra_xudc *xudc = ep->xudc;
        dma_addr_t buf_addr;
        size_t len;

        len = min_t(size_t, XUDC_TRB_MAX_BUFFER_SIZE, req->usb_req.length -
                    req->buf_queued);
        if (len > 0)
                buf_addr = req->usb_req.dma + req->buf_queued;
        else
                buf_addr = 0;

        trb_write_data_ptr(trb, buf_addr);

        trb_write_transfer_len(trb, len);
        trb_write_td_size(trb, req->trbs_needed - req->trbs_queued - 1);

        if (req->trbs_queued == req->trbs_needed - 1 ||
                (req->need_zlp && req->trbs_queued == req->trbs_needed - 2))
                trb_write_chain(trb, 0);
        else
                trb_write_chain(trb, 1);

        trb_write_ioc(trb, ioc);

        if (usb_endpoint_dir_out(ep->desc) ||
            (usb_endpoint_xfer_control(ep->desc) &&
             (xudc->setup_state == DATA_STAGE_RECV)))
                trb_write_isp(trb, 1);
        else
                trb_write_isp(trb, 0);

        if (usb_endpoint_xfer_control(ep->desc)) {
                if (xudc->setup_state == DATA_STAGE_XFER ||
                    xudc->setup_state == DATA_STAGE_RECV)
                        trb_write_type(trb, TRB_TYPE_DATA_STAGE);
                else
                        trb_write_type(trb, TRB_TYPE_STATUS_STAGE);

                if (xudc->setup_state == DATA_STAGE_XFER ||
                    xudc->setup_state == STATUS_STAGE_XFER)
                        trb_write_data_stage_dir(trb, 1);
                else
                        trb_write_data_stage_dir(trb, 0);
        } else if (usb_endpoint_xfer_isoc(ep->desc)) {
                trb_write_type(trb, TRB_TYPE_ISOCH);
                trb_write_sia(trb, 1);
                trb_write_frame_id(trb, 0);
                trb_write_tlbpc(trb, 0);
        } else if (usb_ss_max_streams(ep->comp_desc)) {
                trb_write_type(trb, TRB_TYPE_STREAM);
                trb_write_stream_id(trb, req->usb_req.stream_id);
        } else {
                trb_write_type(trb, TRB_TYPE_NORMAL);
                trb_write_stream_id(trb, 0);
        }

        trb_write_cycle(trb, ep->pcs);

        req->trbs_queued++;
        req->buf_queued += len;

        dump_trb(xudc, "TRANSFER", trb);
}

static unsigned int tegra_xudc_queue_trbs(struct tegra_xudc_ep *ep,
                                          struct tegra_xudc_request *req)
{
        unsigned int i, count, available;
        bool wait_td = false;

        available = ep_available_trbs(ep);
        count = req->trbs_needed - req->trbs_queued;
        if (available < count) {
                count = available;
                ep->ring_full = true;
        }

        /*
         * To generate zero-length packet on USB bus, SW needs schedule a
         * standalone zero-length TD. According to HW's behavior, SW needs
         * to schedule TDs in different ways for different endpoint types.
         *
         * For control endpoint:
         * - Data stage TD (IOC = 1, CH = 0)
         * - Ring doorbell and wait transfer event
         * - Data stage TD for ZLP (IOC = 1, CH = 0)
         * - Ring doorbell
         *
         * For bulk and interrupt endpoints:
         * - Normal transfer TD (IOC = 0, CH = 0)
         * - Normal transfer TD for ZLP (IOC = 1, CH = 0)
         * - Ring doorbell
         */

        if (req->need_zlp && usb_endpoint_xfer_control(ep->desc) && count > 1)
                wait_td = true;

        if (!req->first_trb)
                req->first_trb = &ep->transfer_ring[ep->enq_ptr];

        for (i = 0; i < count; i++) {
                struct tegra_xudc_trb *trb = &ep->transfer_ring[ep->enq_ptr];
                bool ioc = false;

                if ((i == count - 1) || (wait_td && i == count - 2))
                        ioc = true;

                tegra_xudc_queue_one_trb(ep, req, trb, ioc);
                req->last_trb = trb;

                ep->enq_ptr++;
                if (ep->enq_ptr == XUDC_TRANSFER_RING_SIZE - 1) {
                        trb = &ep->transfer_ring[ep->enq_ptr];
                        trb_write_cycle(trb, ep->pcs);
                        ep->pcs = !ep->pcs;
                        ep->enq_ptr = 0;
                }

                if (ioc)
                        break;
        }

        return count;
}

static void tegra_xudc_ep_ring_doorbell(struct tegra_xudc_ep *ep)
{
        struct tegra_xudc *xudc = ep->xudc;
        u32 val;

        if (list_empty(&ep->queue))
                return;

        val = DB_TARGET(ep->index);
        if (usb_endpoint_xfer_control(ep->desc)) {
                val |= DB_STREAMID(xudc->setup_seq_num);
        } else if (usb_ss_max_streams(ep->comp_desc) > 0) {
                struct tegra_xudc_request *req;

                /* Don't ring doorbell if the stream has been rejected. */
                if (ep->stream_rejected)
                        return;

                req = list_first_entry(&ep->queue, struct tegra_xudc_request,
                                       list);
                val |= DB_STREAMID(req->usb_req.stream_id);
        }

        dev_dbg(xudc->dev, "ring doorbell: %#x\n", val);
        xudc_writel(xudc, val, DB);
}

static void tegra_xudc_ep_kick_queue(struct tegra_xudc_ep *ep)
{
        struct tegra_xudc_request *req;
        bool trbs_queued = false;

        list_for_each_entry(req, &ep->queue, list) {
                if (ep->ring_full)
                        break;

                if (tegra_xudc_queue_trbs(ep, req) > 0)
                        trbs_queued = true;
        }

        if (trbs_queued)
                tegra_xudc_ep_ring_doorbell(ep);
}

static int
__tegra_xudc_ep_queue(struct tegra_xudc_ep *ep, struct tegra_xudc_request *req)
{
        struct tegra_xudc *xudc = ep->xudc;
        int err;

        if (usb_endpoint_xfer_control(ep->desc) && !list_empty(&ep->queue)) {
                dev_err(xudc->dev, "control EP has pending transfers\n");
                return -EINVAL;
        }

        if (usb_endpoint_xfer_control(ep->desc)) {
                err = usb_gadget_map_request(&xudc->gadget, &req->usb_req,
                                             (xudc->setup_state ==
                                              DATA_STAGE_XFER));
        } else {
                err = usb_gadget_map_request(&xudc->gadget, &req->usb_req,
                                             usb_endpoint_dir_in(ep->desc));
        }

        if (err < 0) {
                dev_err(xudc->dev, "failed to map request: %d\n", err);
                return err;
        }

        req->first_trb = NULL;
        req->last_trb = NULL;
        req->buf_queued = 0;
        req->trbs_queued = 0;
        req->need_zlp = false;
        req->trbs_needed = DIV_ROUND_UP(req->usb_req.length,
                                        XUDC_TRB_MAX_BUFFER_SIZE);
        if (req->usb_req.length == 0)
                req->trbs_needed++;

        if (!usb_endpoint_xfer_isoc(ep->desc) &&
            req->usb_req.zero && req->usb_req.length &&
            ((req->usb_req.length % ep->usb_ep.maxpacket) == 0)) {
                req->trbs_needed++;
                req->need_zlp = true;
        }

        req->usb_req.status = -EINPROGRESS;
        req->usb_req.actual = 0;

        list_add_tail(&req->list, &ep->queue);

        tegra_xudc_ep_kick_queue(ep);

        return 0;
}

static int
tegra_xudc_ep_queue(struct usb_ep *usb_ep, struct usb_request *usb_req,
                    gfp_t gfp)
{
        struct tegra_xudc_request *req;
        struct tegra_xudc_ep *ep;
        struct tegra_xudc *xudc;
        unsigned long flags;
        int ret;

        if (!usb_ep || !usb_req)
                return -EINVAL;

        ep = to_xudc_ep(usb_ep);
        req = to_xudc_req(usb_req);
        xudc = ep->xudc;

        spin_lock_irqsave(&xudc->lock, flags);
        if (xudc->powergated || !ep->desc) {
                ret = -ESHUTDOWN;
                goto unlock;
        }

        ret = __tegra_xudc_ep_queue(ep, req);
unlock:
        spin_unlock_irqrestore(&xudc->lock, flags);

        return ret;
}

static void squeeze_transfer_ring(struct tegra_xudc_ep *ep,
                                  struct tegra_xudc_request *req)
{
        struct tegra_xudc_trb *trb = req->first_trb;
        bool pcs_enq = trb_read_cycle(trb);
        bool pcs;

        /*
         * Clear out all the TRBs part of or after the cancelled request,
         * and must correct trb cycle bit to the last un-enqueued state.
         */
        while (trb != &ep->transfer_ring[ep->enq_ptr]) {
                pcs = trb_read_cycle(trb);
                memset(trb, 0, sizeof(*trb));
                trb_write_cycle(trb, !pcs);
                trb++;

                if (trb_read_type(trb) == TRB_TYPE_LINK)
                        trb = ep->transfer_ring;
        }

        /* Requests will be re-queued at the start of the cancelled request. */
        ep->enq_ptr = req->first_trb - ep->transfer_ring;
        /*
         * Retrieve the correct cycle bit state from the first trb of
         * the cancelled request.
         */
        ep->pcs = pcs_enq;
        ep->ring_full = false;
        list_for_each_entry_continue(req, &ep->queue, list) {
                req->usb_req.status = -EINPROGRESS;
                req->usb_req.actual = 0;

                req->first_trb = NULL;
                req->last_trb = NULL;
                req->buf_queued = 0;
                req->trbs_queued = 0;
        }
}

/*
 * Determine if the given TRB is in the range [first trb, last trb] for the
 * given request.
 */
static bool trb_in_request(struct tegra_xudc_ep *ep,
                           struct tegra_xudc_request *req,
                           struct tegra_xudc_trb *trb)
{
        dev_dbg(ep->xudc->dev, "%s: request %p -> %p; trb %p\n", __func__,
                req->first_trb, req->last_trb, trb);

        if (trb >= req->first_trb && (trb <= req->last_trb ||
                                      req->last_trb < req->first_trb))
                return true;

        if (trb < req->first_trb && trb <= req->last_trb &&
            req->last_trb < req->first_trb)
                return true;

        return false;
}

/*
 * Determine if the given TRB is in the range [EP enqueue pointer, first TRB)
 * for the given endpoint and request.
 */
static bool trb_before_request(struct tegra_xudc_ep *ep,
                               struct tegra_xudc_request *req,
                               struct tegra_xudc_trb *trb)
{
        struct tegra_xudc_trb *enq_trb = &ep->transfer_ring[ep->enq_ptr];

        dev_dbg(ep->xudc->dev, "%s: request %p -> %p; enq ptr: %p; trb %p\n",
                __func__, req->first_trb, req->last_trb, enq_trb, trb);

        if (trb < req->first_trb && (enq_trb <= trb ||
                                     req->first_trb < enq_trb))
                return true;

        if (trb > req->first_trb && req->first_trb < enq_trb && enq_trb <= trb)
                return true;

        return false;
}

static int
__tegra_xudc_ep_dequeue(struct tegra_xudc_ep *ep,
                        struct tegra_xudc_request *req)
{
        struct tegra_xudc *xudc = ep->xudc;
        struct tegra_xudc_request *r;
        struct tegra_xudc_trb *deq_trb;
        bool busy, kick_queue = false;
        int ret = 0;

        /* Make sure the request is actually queued to this endpoint. */
        list_for_each_entry(r, &ep->queue, list) {
                if (r == req)
                        break;
        }

        if (r != req)
                return -EINVAL;

        /* Request hasn't been queued in the transfer ring yet. */
        if (!req->trbs_queued) {
                tegra_xudc_req_done(ep, req, -ECONNRESET);
                return 0;
        }

        /* Halt DMA for this endpiont. */
        if (ep_ctx_read_state(ep->context) == EP_STATE_RUNNING) {
                ep_pause(xudc, ep->index);
                ep_wait_for_inactive(xudc, ep->index);
        }

        deq_trb = trb_phys_to_virt(ep, ep_ctx_read_deq_ptr(ep->context));
        /* Is the hardware processing the TRB at the dequeue pointer? */
        busy = (trb_read_cycle(deq_trb) == ep_ctx_read_dcs(ep->context));

        if (trb_in_request(ep, req, deq_trb) && busy) {
                /*
                 * Request has been partially completed or it hasn't
                 * started processing yet.
                 */
                dma_addr_t deq_ptr;

                squeeze_transfer_ring(ep, req);

                req->usb_req.actual = ep_ctx_read_edtla(ep->context);
                tegra_xudc_req_done(ep, req, -ECONNRESET);
                kick_queue = true;

                /* EDTLA is > 0: request has been partially completed */
                if (req->usb_req.actual > 0) {
                        /*
                         * Abort the pending transfer and update the dequeue
                         * pointer
                         */
                        ep_ctx_write_edtla(ep->context, 0);
                        ep_ctx_write_partial_td(ep->context, 0);
                        ep_ctx_write_data_offset(ep->context, 0);

                        deq_ptr = trb_virt_to_phys(ep,
                                        &ep->transfer_ring[ep->enq_ptr]);

                        if (dma_mapping_error(xudc->dev, deq_ptr)) {
                                ret = -EINVAL;
                        } else {
                                ep_ctx_write_deq_ptr(ep->context, deq_ptr);
                                ep_ctx_write_dcs(ep->context, ep->pcs);
                                ep_reload(xudc, ep->index);
                        }
                }
        } else if (trb_before_request(ep, req, deq_trb) && busy) {
                /* Request hasn't started processing yet. */
                squeeze_transfer_ring(ep, req);

                tegra_xudc_req_done(ep, req, -ECONNRESET);
                kick_queue = true;
        } else {
                /*
                 * Request has completed, but we haven't processed the
                 * completion event yet.
                 */
                tegra_xudc_req_done(ep, req, -ECONNRESET);
                ret = -EINVAL;
        }

        /* Resume the endpoint. */
        ep_unpause(xudc, ep->index);

        if (kick_queue)
                tegra_xudc_ep_kick_queue(ep);

        return ret;
}

static int
tegra_xudc_ep_dequeue(struct usb_ep *usb_ep, struct usb_request *usb_req)
{
        struct tegra_xudc_request *req;
        struct tegra_xudc_ep *ep;
        struct tegra_xudc *xudc;
        unsigned long flags;
        int ret;

        if (!usb_ep || !usb_req)
                return -EINVAL;

        ep = to_xudc_ep(usb_ep);
        req = to_xudc_req(usb_req);
        xudc = ep->xudc;

        spin_lock_irqsave(&xudc->lock, flags);

        if (xudc->powergated || !ep->desc) {
                ret = -ESHUTDOWN;
                goto unlock;
        }

        ret = __tegra_xudc_ep_dequeue(ep, req);
unlock:
        spin_unlock_irqrestore(&xudc->lock, flags);

        return ret;
}

static int __tegra_xudc_ep_set_halt(struct tegra_xudc_ep *ep, bool halt)
{
        struct tegra_xudc *xudc = ep->xudc;

        if (!ep->desc)
                return -EINVAL;

        if (usb_endpoint_xfer_isoc(ep->desc)) {
                dev_err(xudc->dev, "can't halt isochronous EP\n");
                return -ENOTSUPP;
        }

        if (!!(xudc_readl(xudc, EP_HALT) & BIT(ep->index)) == halt) {
                dev_dbg(xudc->dev, "EP %u already %s\n", ep->index,
                        halt ? "halted" : "not halted");
                return 0;
        }

        if (halt) {
                ep_halt(xudc, ep->index);
        } else {
                ep_ctx_write_state(ep->context, EP_STATE_DISABLED);

                ep_reload(xudc, ep->index);

                ep_ctx_write_state(ep->context, EP_STATE_RUNNING);
                ep_ctx_write_seq_num(ep->context, 0);

                ep_reload(xudc, ep->index);
                ep_unpause(xudc, ep->index);
                ep_unhalt(xudc, ep->index);

                tegra_xudc_ep_ring_doorbell(ep);
        }

        return 0;
}

static int tegra_xudc_ep_set_halt(struct usb_ep *usb_ep, int value)
{
        struct tegra_xudc_ep *ep;
        struct tegra_xudc *xudc;
        unsigned long flags;
        int ret;

        if (!usb_ep)
                return -EINVAL;

        ep = to_xudc_ep(usb_ep);
        xudc = ep->xudc;

        spin_lock_irqsave(&xudc->lock, flags);
        if (xudc->powergated) {
                ret = -ESHUTDOWN;
                goto unlock;
        }

        if (value && usb_endpoint_dir_in(ep->desc) &&
            !list_empty(&ep->queue)) {
                dev_err(xudc->dev, "can't halt EP with requests pending\n");
                ret = -EAGAIN;
                goto unlock;
        }

        ret = __tegra_xudc_ep_set_halt(ep, value);
unlock:
        spin_unlock_irqrestore(&xudc->lock, flags);

        return ret;
}

static void tegra_xudc_ep_context_setup(struct tegra_xudc_ep *ep)
{
        const struct usb_endpoint_descriptor *desc = ep->desc;
        const struct usb_ss_ep_comp_descriptor *comp_desc = ep->comp_desc;
        struct tegra_xudc *xudc = ep->xudc;
        u16 maxpacket, maxburst = 0, esit = 0;
        u32 val;

        maxpacket = usb_endpoint_maxp(desc);
        if (xudc->gadget.speed == USB_SPEED_SUPER) {
                if (!usb_endpoint_xfer_control(desc))
                        maxburst = comp_desc->bMaxBurst;

                if (usb_endpoint_xfer_int(desc) || usb_endpoint_xfer_isoc(desc))
                        esit = le16_to_cpu(comp_desc->wBytesPerInterval);
        } else if ((xudc->gadget.speed < USB_SPEED_SUPER) &&
                   (usb_endpoint_xfer_int(desc) ||
                    usb_endpoint_xfer_isoc(desc))) {
                if (xudc->gadget.speed == USB_SPEED_HIGH) {
                        maxburst = usb_endpoint_maxp_mult(desc) - 1;
                        if (maxburst == 0x3) {
                                dev_warn(xudc->dev,
                                         "invalid endpoint maxburst\n");
                                maxburst = 0x2;
                        }
                }
                esit = maxpacket * (maxburst + 1);
        }

        memset(ep->context, 0, sizeof(*ep->context));

        ep_ctx_write_state(ep->context, EP_STATE_RUNNING);
        ep_ctx_write_interval(ep->context, desc->bInterval);
        if (xudc->gadget.speed == USB_SPEED_SUPER) {
                if (usb_endpoint_xfer_isoc(desc)) {
                        ep_ctx_write_mult(ep->context,
                                          comp_desc->bmAttributes & 0x3);
                }

                if (usb_endpoint_xfer_bulk(desc)) {
                        ep_ctx_write_max_pstreams(ep->context,
                                                  comp_desc->bmAttributes &
                                                  0x1f);
                        ep_ctx_write_lsa(ep->context, 1);
                }
        }

        if (!usb_endpoint_xfer_control(desc) && usb_endpoint_dir_out(desc))
                val = usb_endpoint_type(desc);
        else
                val = usb_endpoint_type(desc) + EP_TYPE_CONTROL;

        ep_ctx_write_type(ep->context, val);
        ep_ctx_write_cerr(ep->context, 0x3);
        ep_ctx_write_max_packet_size(ep->context, maxpacket);
        ep_ctx_write_max_burst_size(ep->context, maxburst);

        ep_ctx_write_deq_ptr(ep->context, ep->transfer_ring_phys);
        ep_ctx_write_dcs(ep->context, ep->pcs);

        /* Select a reasonable average TRB length based on endpoint type. */
        switch (usb_endpoint_type(desc)) {
        case USB_ENDPOINT_XFER_CONTROL:
                val = 8;
                break;
        case USB_ENDPOINT_XFER_INT:
                val = 1024;
                break;
        case USB_ENDPOINT_XFER_BULK:
        case USB_ENDPOINT_XFER_ISOC:
        default:
                val = 3072;
                break;
        }

        ep_ctx_write_avg_trb_len(ep->context, val);
        ep_ctx_write_max_esit_payload(ep->context, esit);

        ep_ctx_write_cerrcnt(ep->context, 0x3);
}

static void setup_link_trb(struct tegra_xudc_ep *ep,
                           struct tegra_xudc_trb *trb)
{
        trb_write_data_ptr(trb, ep->transfer_ring_phys);
        trb_write_type(trb, TRB_TYPE_LINK);
        trb_write_toggle_cycle(trb, 1);
}

static int __tegra_xudc_ep_disable(struct tegra_xudc_ep *ep)
{
        struct tegra_xudc *xudc = ep->xudc;

        if (ep_ctx_read_state(ep->context) == EP_STATE_DISABLED) {
                dev_err(xudc->dev, "endpoint %u already disabled\n",
                        ep->index);
                return -EINVAL;
        }

        ep_ctx_write_state(ep->context, EP_STATE_DISABLED);

        ep_reload(xudc, ep->index);

        tegra_xudc_ep_nuke(ep, -ESHUTDOWN);

        xudc->nr_enabled_eps--;
        if (usb_endpoint_xfer_isoc(ep->desc))
                xudc->nr_isoch_eps--;

        ep->desc = NULL;
        ep->comp_desc = NULL;

        memset(ep->context, 0, sizeof(*ep->context));

        ep_unpause(xudc, ep->index);
        ep_unhalt(xudc, ep->index);
        if (xudc_readl(xudc, EP_STOPPED) & BIT(ep->index))
                xudc_writel(xudc, BIT(ep->index), EP_STOPPED);

        /*
         * If this is the last endpoint disabled in a de-configure request,
         * switch back to address state.
         */
        if ((xudc->device_state == USB_STATE_CONFIGURED) &&
            (xudc->nr_enabled_eps == 1)) {
                u32 val;

                xudc->device_state = USB_STATE_ADDRESS;
                usb_gadget_set_state(&xudc->gadget, xudc->device_state);

                val = xudc_readl(xudc, CTRL);
                val &= ~CTRL_RUN;
                xudc_writel(xudc, val, CTRL);
        }

        dev_info(xudc->dev, "ep %u disabled\n", ep->index);

        return 0;
}

static int tegra_xudc_ep_disable(struct usb_ep *usb_ep)
{
        struct tegra_xudc_ep *ep;
        struct tegra_xudc *xudc;
        unsigned long flags;
        int ret;

        if (!usb_ep)
                return -EINVAL;

        ep = to_xudc_ep(usb_ep);
        xudc = ep->xudc;

        spin_lock_irqsave(&xudc->lock, flags);
        if (xudc->powergated) {
                ret = -ESHUTDOWN;
                goto unlock;
        }

        ret = __tegra_xudc_ep_disable(ep);
unlock:
        spin_unlock_irqrestore(&xudc->lock, flags);

        return ret;
}

static int __tegra_xudc_ep_enable(struct tegra_xudc_ep *ep,
                                  const struct usb_endpoint_descriptor *desc)
{
        struct tegra_xudc *xudc = ep->xudc;
        unsigned int i;
        u32 val;

        if (xudc->gadget.speed == USB_SPEED_SUPER &&
                !usb_endpoint_xfer_control(desc) && !ep->usb_ep.comp_desc)
                return -EINVAL;

        /* Disable the EP if it is not disabled */
        if (ep_ctx_read_state(ep->context) != EP_STATE_DISABLED)
                __tegra_xudc_ep_disable(ep);

        ep->desc = desc;
        ep->comp_desc = ep->usb_ep.comp_desc;

        if (usb_endpoint_xfer_isoc(desc)) {
                if (xudc->nr_isoch_eps > XUDC_MAX_ISOCH_EPS) {
                        dev_err(xudc->dev, "too many isochronous endpoints\n");
                        return -EBUSY;
                }
                xudc->nr_isoch_eps++;
        }

        memset(ep->transfer_ring, 0, XUDC_TRANSFER_RING_SIZE *
               sizeof(*ep->transfer_ring));
        setup_link_trb(ep, &ep->transfer_ring[XUDC_TRANSFER_RING_SIZE - 1]);

        ep->enq_ptr = 0;
        ep->deq_ptr = 0;
        ep->pcs = true;
        ep->ring_full = false;
        xudc->nr_enabled_eps++;

        tegra_xudc_ep_context_setup(ep);

        /*
         * No need to reload and un-halt EP0.  This will be done automatically
         * once a valid SETUP packet is received.
         */
        if (usb_endpoint_xfer_control(desc))
                goto out;

        /*
         * Transition to configured state once the first non-control
         * endpoint is enabled.
         */
        if (xudc->device_state == USB_STATE_ADDRESS) {
                val = xudc_readl(xudc, CTRL);
                val |= CTRL_RUN;
                xudc_writel(xudc, val, CTRL);

                xudc->device_state = USB_STATE_CONFIGURED;
                usb_gadget_set_state(&xudc->gadget, xudc->device_state);
        }

        if (usb_endpoint_xfer_isoc(desc)) {
                /*
                 * Pause all bulk endpoints when enabling an isoch endpoint
                 * to ensure the isoch endpoint is allocated enough bandwidth.
                 */
                for (i = 0; i < ARRAY_SIZE(xudc->ep); i++) {
                        if (xudc->ep[i].desc &&
                            usb_endpoint_xfer_bulk(xudc->ep[i].desc))
                                ep_pause(xudc, i);
                }
        }

        ep_reload(xudc, ep->index);
        ep_unpause(xudc, ep->index);
        ep_unhalt(xudc, ep->index);

        if (usb_endpoint_xfer_isoc(desc)) {
                for (i = 0; i < ARRAY_SIZE(xudc->ep); i++) {
                        if (xudc->ep[i].desc &&
                            usb_endpoint_xfer_bulk(xudc->ep[i].desc))
                                ep_unpause(xudc, i);
                }
        }

out:
        dev_info(xudc->dev, "EP %u (type: %s, dir: %s) enabled\n", ep->index,
                 usb_ep_type_string(usb_endpoint_type(ep->desc)),
                 usb_endpoint_dir_in(ep->desc) ? "in" : "out");

        return 0;
}

static int tegra_xudc_ep_enable(struct usb_ep *usb_ep,
                                const struct usb_endpoint_descriptor *desc)
{
        struct tegra_xudc_ep *ep;
        struct tegra_xudc *xudc;
        unsigned long flags;
        int ret;

        if  (!usb_ep || !desc || (desc->bDescriptorType != USB_DT_ENDPOINT))
                return -EINVAL;

        ep = to_xudc_ep(usb_ep);
        xudc = ep->xudc;

        spin_lock_irqsave(&xudc->lock, flags);
        if (xudc->powergated) {
                ret = -ESHUTDOWN;
                goto unlock;
        }

        ret = __tegra_xudc_ep_enable(ep, desc);
unlock:
        spin_unlock_irqrestore(&xudc->lock, flags);

        return ret;
}

static struct usb_request *
tegra_xudc_ep_alloc_request(struct usb_ep *usb_ep, gfp_t gfp)
{
        struct tegra_xudc_request *req;

        req = kzalloc(sizeof(*req), gfp);
        if (!req)
                return NULL;

        INIT_LIST_HEAD(&req->list);

        return &req->usb_req;
}

static void tegra_xudc_ep_free_request(struct usb_ep *usb_ep,
                                       struct usb_request *usb_req)
{
        struct tegra_xudc_request *req = to_xudc_req(usb_req);

        kfree(req);
}

static const struct usb_ep_ops tegra_xudc_ep_ops = {
        .enable = tegra_xudc_ep_enable,
        .disable = tegra_xudc_ep_disable,
        .alloc_request = tegra_xudc_ep_alloc_request,
        .free_request = tegra_xudc_ep_free_request,
        .queue = tegra_xudc_ep_queue,
        .dequeue = tegra_xudc_ep_dequeue,
        .set_halt = tegra_xudc_ep_set_halt,
};

static int tegra_xudc_ep0_enable(struct usb_ep *usb_ep,
                                 const struct usb_endpoint_descriptor *desc)
{
        return -EBUSY;
}

static int tegra_xudc_ep0_disable(struct usb_ep *usb_ep)
{
        return -EBUSY;
}

static const struct usb_ep_ops tegra_xudc_ep0_ops = {
        .enable = tegra_xudc_ep0_enable,
        .disable = tegra_xudc_ep0_disable,
        .alloc_request = tegra_xudc_ep_alloc_request,
        .free_request = tegra_xudc_ep_free_request,
        .queue = tegra_xudc_ep_queue,
        .dequeue = tegra_xudc_ep_dequeue,
        .set_halt = tegra_xudc_ep_set_halt,
};

static int tegra_xudc_gadget_get_frame(struct usb_gadget *gadget)
{
        struct tegra_xudc *xudc = to_xudc(gadget);
        unsigned long flags;
        int ret;

        spin_lock_irqsave(&xudc->lock, flags);
        if (xudc->powergated) {
                ret = -ESHUTDOWN;
                goto unlock;
        }

        ret = (xudc_readl(xudc, MFINDEX) & MFINDEX_FRAME_MASK) >>
                MFINDEX_FRAME_SHIFT;
unlock:
        spin_unlock_irqrestore(&xudc->lock, flags);

        return ret;
}

static void tegra_xudc_resume_device_state(struct tegra_xudc *xudc)
{
        unsigned int i;
        u32 val;

        ep_unpause_all(xudc);

        /* Direct link to U0. */
        val = xudc_readl(xudc, PORTSC);
        if (((val & PORTSC_PLS_MASK) >> PORTSC_PLS_SHIFT) != PORTSC_PLS_U0) {
                val &= ~(PORTSC_CHANGE_MASK | PORTSC_PLS_MASK);
                val |= PORTSC_LWS | PORTSC_PLS(PORTSC_PLS_U0);
                xudc_writel(xudc, val, PORTSC);
        }

        if (xudc->device_state == USB_STATE_SUSPENDED) {
                xudc->device_state = xudc->resume_state;
                usb_gadget_set_state(&xudc->gadget, xudc->device_state);
                xudc->resume_state = 0;
        }

        /*
         * Doorbells may be dropped if they are sent too soon (< ~200ns)
         * after unpausing the endpoint.  Wait for 500ns just to be safe.
         */
        ndelay(500);
        for (i = 0; i < ARRAY_SIZE(xudc->ep); i++)
                tegra_xudc_ep_ring_doorbell(&xudc->ep[i]);
}

static int tegra_xudc_gadget_wakeup(struct usb_gadget *gadget)
{
        struct tegra_xudc *xudc = to_xudc(gadget);
        unsigned long flags;
        int ret = 0;
        u32 val;

        spin_lock_irqsave(&xudc->lock, flags);

        if (xudc->powergated) {

                ret = -ESHUTDOWN;
                goto unlock;
        }
        val = xudc_readl(xudc, PORTPM);
        dev_dbg(xudc->dev, "%s: PORTPM=%#x, speed=%x\n", __func__,
                        val, gadget->speed);

        if (((xudc->gadget.speed <= USB_SPEED_HIGH) &&
             (val & PORTPM_RWE)) ||
            ((xudc->gadget.speed == USB_SPEED_SUPER) &&
             (val & PORTPM_FRWE))) {
                tegra_xudc_resume_device_state(xudc);

                /* Send Device Notification packet. */
                if (xudc->gadget.speed == USB_SPEED_SUPER) {
                        val = DEVNOTIF_LO_TYPE(DEVNOTIF_LO_TYPE_FUNCTION_WAKE)
                                             | DEVNOTIF_LO_TRIG;
                        xudc_writel(xudc, 0, DEVNOTIF_HI);
                        xudc_writel(xudc, val, DEVNOTIF_LO);
                }
        }

unlock:
        dev_dbg(xudc->dev, "%s: ret value is %d", __func__, ret);
        spin_unlock_irqrestore(&xudc->lock, flags);

        return ret;
}

static int tegra_xudc_gadget_pullup(struct usb_gadget *gadget, int is_on)
{
        struct tegra_xudc *xudc = to_xudc(gadget);
        unsigned long flags;
        u32 val;

        pm_runtime_get_sync(xudc->dev);

        spin_lock_irqsave(&xudc->lock, flags);

        if (is_on != xudc->pullup) {
                val = xudc_readl(xudc, CTRL);
                if (is_on)
                        val |= CTRL_ENABLE;
                else
                        val &= ~CTRL_ENABLE;
                xudc_writel(xudc, val, CTRL);
        }

        xudc->pullup = is_on;
        dev_dbg(xudc->dev, "%s: pullup:%d", __func__, is_on);

        spin_unlock_irqrestore(&xudc->lock, flags);

        pm_runtime_put(xudc->dev);

        return 0;
}

static int tegra_xudc_gadget_start(struct usb_gadget *gadget,
                                   struct usb_gadget_driver *driver)
{
        struct tegra_xudc *xudc = to_xudc(gadget);
        unsigned long flags;
        u32 val;
        int ret;
        unsigned int i;

        if (!driver)
                return -EINVAL;

        pm_runtime_get_sync(xudc->dev);

        spin_lock_irqsave(&xudc->lock, flags);

        if (xudc->driver) {
                ret = -EBUSY;
                goto unlock;
        }

        xudc->setup_state = WAIT_FOR_SETUP;
        xudc->device_state = USB_STATE_DEFAULT;
        usb_gadget_set_state(&xudc->gadget, xudc->device_state);

        ret = __tegra_xudc_ep_enable(&xudc->ep[0], &tegra_xudc_ep0_desc);
        if (ret < 0)
                goto unlock;

        val = xudc_readl(xudc, CTRL);
        val |= CTRL_IE | CTRL_LSE;
        xudc_writel(xudc, val, CTRL);

        val = xudc_readl(xudc, PORTHALT);
        val |= PORTHALT_STCHG_INTR_EN;
        xudc_writel(xudc, val, PORTHALT);

        if (xudc->pullup) {
                val = xudc_readl(xudc, CTRL);
                val |= CTRL_ENABLE;
                xudc_writel(xudc, val, CTRL);
        }

        for (i = 0; i < xudc->soc->num_phys; i++)
                if (xudc->usbphy[i])
                        otg_set_peripheral(xudc->usbphy[i]->otg, gadget);

        xudc->driver = driver;
unlock:
        dev_dbg(xudc->dev, "%s: ret value is %d", __func__, ret);
        spin_unlock_irqrestore(&xudc->lock, flags);

        pm_runtime_put(xudc->dev);

        return ret;
}

static int tegra_xudc_gadget_stop(struct usb_gadget *gadget)
{
        struct tegra_xudc *xudc = to_xudc(gadget);
        unsigned long flags;
        u32 val;
        unsigned int i;

        pm_runtime_get_sync(xudc->dev);

        spin_lock_irqsave(&xudc->lock, flags);

        for (i = 0; i < xudc->soc->num_phys; i++)
                if (xudc->usbphy[i])
                        otg_set_peripheral(xudc->usbphy[i]->otg, NULL);

        val = xudc_readl(xudc, CTRL);
        val &= ~(CTRL_IE | CTRL_ENABLE);
        xudc_writel(xudc, val, CTRL);

        __tegra_xudc_ep_disable(&xudc->ep[0]);

        xudc->driver = NULL;
        dev_dbg(xudc->dev, "Gadget stopped");

        spin_unlock_irqrestore(&xudc->lock, flags);

        pm_runtime_put(xudc->dev);

        return 0;
}

static int tegra_xudc_gadget_vbus_draw(struct usb_gadget *gadget,
                                                unsigned int m_a)
{
        int ret = 0;
        struct tegra_xudc *xudc = to_xudc(gadget);

        dev_dbg(xudc->dev, "%s: %u mA\n", __func__, m_a);

        if (xudc->curr_usbphy->chg_type == SDP_TYPE)
                ret = usb_phy_set_power(xudc->curr_usbphy, m_a);

        return ret;
}

static int tegra_xudc_set_selfpowered(struct usb_gadget *gadget, int is_on)
{
        struct tegra_xudc *xudc = to_xudc(gadget);

        dev_dbg(xudc->dev, "%s: %d\n", __func__, is_on);
        xudc->selfpowered = !!is_on;

        return 0;
}

static const struct usb_gadget_ops tegra_xudc_gadget_ops = {
        .get_frame = tegra_xudc_gadget_get_frame,
        .wakeup = tegra_xudc_gadget_wakeup,
        .pullup = tegra_xudc_gadget_pullup,
        .udc_start = tegra_xudc_gadget_start,
        .udc_stop = tegra_xudc_gadget_stop,
        .vbus_draw = tegra_xudc_gadget_vbus_draw,
        .set_selfpowered = tegra_xudc_set_selfpowered,
};

static void no_op_complete(struct usb_ep *ep, struct usb_request *req)
{
}

static int
tegra_xudc_ep0_queue_status(struct tegra_xudc *xudc,
                void (*cmpl)(struct usb_ep *, struct usb_request *))
{
        xudc->ep0_req->usb_req.buf = NULL;
        xudc->ep0_req->usb_req.dma = 0;
        xudc->ep0_req->usb_req.length = 0;
        xudc->ep0_req->usb_req.complete = cmpl;
        xudc->ep0_req->usb_req.context = xudc;

        return __tegra_xudc_ep_queue(&xudc->ep[0], xudc->ep0_req);
}

static int
tegra_xudc_ep0_queue_data(struct tegra_xudc *xudc, void *buf, size_t len,
                void (*cmpl)(struct usb_ep *, struct usb_request *))
{
        xudc->ep0_req->usb_req.buf = buf;
        xudc->ep0_req->usb_req.length = len;
        xudc->ep0_req->usb_req.complete = cmpl;
        xudc->ep0_req->usb_req.context = xudc;

        return __tegra_xudc_ep_queue(&xudc->ep[0], xudc->ep0_req);
}

static void tegra_xudc_ep0_req_done(struct tegra_xudc *xudc)
{
        switch (xudc->setup_state) {
        case DATA_STAGE_XFER:
                xudc->setup_state = STATUS_STAGE_RECV;
                tegra_xudc_ep0_queue_status(xudc, no_op_complete);
                break;
        case DATA_STAGE_RECV:
                xudc->setup_state = STATUS_STAGE_XFER;
                tegra_xudc_ep0_queue_status(xudc, no_op_complete);
                break;
        default:
                xudc->setup_state = WAIT_FOR_SETUP;
                break;
        }
}

static int tegra_xudc_ep0_delegate_req(struct tegra_xudc *xudc,
                                       struct usb_ctrlrequest *ctrl)
{
        int ret;

        spin_unlock(&xudc->lock);
        ret = xudc->driver->setup(&xudc->gadget, ctrl);
        spin_lock(&xudc->lock);

        return ret;
}

static void set_feature_complete(struct usb_ep *ep, struct usb_request *req)
{
        struct tegra_xudc *xudc = req->context;

        if (xudc->test_mode_pattern) {
                xudc_writel(xudc, xudc->test_mode_pattern, PORT_TM);
                xudc->test_mode_pattern = 0;
        }
}

static int tegra_xudc_ep0_set_feature(struct tegra_xudc *xudc,
                                      struct usb_ctrlrequest *ctrl)
{
        bool set = (ctrl->bRequest == USB_REQ_SET_FEATURE);
        u32 feature = le16_to_cpu(ctrl->wValue);
        u32 index = le16_to_cpu(ctrl->wIndex);
        u32 val, ep;
        int ret;

        if (le16_to_cpu(ctrl->wLength) != 0)
                return -EINVAL;

        switch (ctrl->bRequestType & USB_RECIP_MASK) {
        case USB_RECIP_DEVICE:
                switch (feature) {
                case USB_DEVICE_REMOTE_WAKEUP:
                        if ((xudc->gadget.speed == USB_SPEED_SUPER) ||
                            (xudc->device_state == USB_STATE_DEFAULT))
                                return -EINVAL;

                        val = xudc_readl(xudc, PORTPM);
                        if (set)
                                val |= PORTPM_RWE;
                        else
                                val &= ~PORTPM_RWE;

                        xudc_writel(xudc, val, PORTPM);
                        break;
                case USB_DEVICE_U1_ENABLE:
                case USB_DEVICE_U2_ENABLE:
                        if ((xudc->device_state != USB_STATE_CONFIGURED) ||
                            (xudc->gadget.speed != USB_SPEED_SUPER))
                                return -EINVAL;

                        val = xudc_readl(xudc, PORTPM);
                        if ((feature == USB_DEVICE_U1_ENABLE) &&
                             xudc->soc->u1_enable) {
                                if (set)
                                        val |= PORTPM_U1E;
                                else
                                        val &= ~PORTPM_U1E;
                        }

                        if ((feature == USB_DEVICE_U2_ENABLE) &&
                             xudc->soc->u2_enable) {
                                if (set)
                                        val |= PORTPM_U2E;
                                else
                                        val &= ~PORTPM_U2E;
                        }

                        xudc_writel(xudc, val, PORTPM);
                        break;
                case USB_DEVICE_TEST_MODE:
                        if (xudc->gadget.speed != USB_SPEED_HIGH)
                                return -EINVAL;

                        if (!set)
                                return -EINVAL;

                        xudc->test_mode_pattern = index >> 8;
                        break;
                default:
                        return -EINVAL;
                }

                break;
        case USB_RECIP_INTERFACE:
                if (xudc->device_state != USB_STATE_CONFIGURED)
                        return -EINVAL;

                switch (feature) {
                case USB_INTRF_FUNC_SUSPEND:
                        if (set) {
                                val = xudc_readl(xudc, PORTPM);

                                if (index & USB_INTRF_FUNC_SUSPEND_RW)
                                        val |= PORTPM_FRWE;
                                else
                                        val &= ~PORTPM_FRWE;

                                xudc_writel(xudc, val, PORTPM);
                        }

                        return tegra_xudc_ep0_delegate_req(xudc, ctrl);
                default:
                        return -EINVAL;
                }

                break;
        case USB_RECIP_ENDPOINT:
                ep = (index & USB_ENDPOINT_NUMBER_MASK) * 2 +
                        ((index & USB_DIR_IN) ? 1 : 0);

                if ((xudc->device_state == USB_STATE_DEFAULT) ||
                    ((xudc->device_state == USB_STATE_ADDRESS) &&
                     (index != 0)))
                        return -EINVAL;

                ret = __tegra_xudc_ep_set_halt(&xudc->ep[ep], set);
                if (ret < 0)
                        return ret;
                break;
        default:
                return -EINVAL;
        }

        return tegra_xudc_ep0_queue_status(xudc, set_feature_complete);
}

static int tegra_xudc_ep0_get_status(struct tegra_xudc *xudc,
                                     struct usb_ctrlrequest *ctrl)
{
        struct tegra_xudc_ep_context *ep_ctx;
        u32 val, ep, index = le16_to_cpu(ctrl->wIndex);
        u16 status = 0;

        if (!(ctrl->bRequestType & USB_DIR_IN))
                return -EINVAL;

        if ((le16_to_cpu(ctrl->wValue) != 0) ||
            (le16_to_cpu(ctrl->wLength) != 2))
                return -EINVAL;

        switch (ctrl->bRequestType & USB_RECIP_MASK) {
        case USB_RECIP_DEVICE:
                val = xudc_readl(xudc, PORTPM);

                if (xudc->selfpowered)
                        status |= BIT(USB_DEVICE_SELF_POWERED);

                if ((xudc->gadget.speed < USB_SPEED_SUPER) &&
                    (val & PORTPM_RWE))
                        status |= BIT(USB_DEVICE_REMOTE_WAKEUP);

                if (xudc->gadget.speed == USB_SPEED_SUPER) {
                        if (val & PORTPM_U1E)
                                status |= BIT(USB_DEV_STAT_U1_ENABLED);
                        if (val & PORTPM_U2E)
                                status |= BIT(USB_DEV_STAT_U2_ENABLED);
                }
                break;
        case USB_RECIP_INTERFACE:
                if (xudc->gadget.speed == USB_SPEED_SUPER) {
                        status |= USB_INTRF_STAT_FUNC_RW_CAP;
                        val = xudc_readl(xudc, PORTPM);
                        if (val & PORTPM_FRWE)
                                status |= USB_INTRF_STAT_FUNC_RW;
                }
                break;
        case USB_RECIP_ENDPOINT:
                ep = (index & USB_ENDPOINT_NUMBER_MASK) * 2 +
                        ((index & USB_DIR_IN) ? 1 : 0);
                ep_ctx = &xudc->ep_context[ep];

                if ((xudc->device_state != USB_STATE_CONFIGURED) &&
                    ((xudc->device_state != USB_STATE_ADDRESS) || (ep != 0)))
                        return -EINVAL;

                if (ep_ctx_read_state(ep_ctx) == EP_STATE_DISABLED)
                        return -EINVAL;

                if (xudc_readl(xudc, EP_HALT) & BIT(ep))
                        status |= BIT(USB_ENDPOINT_HALT);
                break;
        default:
                return -EINVAL;
        }

        xudc->status_buf = cpu_to_le16(status);
        return tegra_xudc_ep0_queue_data(xudc, &xudc->status_buf,
                                         sizeof(xudc->status_buf),
                                         no_op_complete);
}

static void set_sel_complete(struct usb_ep *ep, struct usb_request *req)
{
        /* Nothing to do with SEL values */
}

static int tegra_xudc_ep0_set_sel(struct tegra_xudc *xudc,
                                  struct usb_ctrlrequest *ctrl)
{
        if (ctrl->bRequestType != (USB_DIR_OUT | USB_RECIP_DEVICE |
                                     USB_TYPE_STANDARD))
                return -EINVAL;

        if (xudc->device_state == USB_STATE_DEFAULT)
                return -EINVAL;

        if ((le16_to_cpu(ctrl->wIndex) != 0) ||
            (le16_to_cpu(ctrl->wValue) != 0) ||
            (le16_to_cpu(ctrl->wLength) != 6))
                return -EINVAL;

        return tegra_xudc_ep0_queue_data(xudc, &xudc->sel_timing,
                                         sizeof(xudc->sel_timing),
                                         set_sel_complete);
}

static void set_isoch_delay_complete(struct usb_ep *ep, struct usb_request *req)
{
        /* Nothing to do with isoch delay */
}

static int tegra_xudc_ep0_set_isoch_delay(struct tegra_xudc *xudc,
                                          struct usb_ctrlrequest *ctrl)
{
        u32 delay = le16_to_cpu(ctrl->wValue);

        if (ctrl->bRequestType != (USB_DIR_OUT | USB_RECIP_DEVICE |
                                   USB_TYPE_STANDARD))
                return -EINVAL;

        if ((delay > 65535) || (le16_to_cpu(ctrl->wIndex) != 0) ||
            (le16_to_cpu(ctrl->wLength) != 0))
                return -EINVAL;

        xudc->isoch_delay = delay;

        return tegra_xudc_ep0_queue_status(xudc, set_isoch_delay_complete);
}

static void set_address_complete(struct usb_ep *ep, struct usb_request *req)
{
        struct tegra_xudc *xudc = req->context;

        if ((xudc->device_state == USB_STATE_DEFAULT) &&
            (xudc->dev_addr != 0)) {
                xudc->device_state = USB_STATE_ADDRESS;
                usb_gadget_set_state(&xudc->gadget, xudc->device_state);
        } else if ((xudc->device_state == USB_STATE_ADDRESS) &&
                   (xudc->dev_addr == 0)) {
                xudc->device_state = USB_STATE_DEFAULT;
                usb_gadget_set_state(&xudc->gadget, xudc->device_state);
        }
}

static int tegra_xudc_ep0_set_address(struct tegra_xudc *xudc,
                                      struct usb_ctrlrequest *ctrl)
{
        struct tegra_xudc_ep *ep0 = &xudc->ep[0];
        u32 val, addr = le16_to_cpu(ctrl->wValue);

        if (ctrl->bRequestType != (USB_DIR_OUT | USB_RECIP_DEVICE |
                                     USB_TYPE_STANDARD))
                return -EINVAL;

        if ((addr > 127) || (le16_to_cpu(ctrl->wIndex) != 0) ||
            (le16_to_cpu(ctrl->wLength) != 0))
                return -EINVAL;

        if (xudc->device_state == USB_STATE_CONFIGURED)
                return -EINVAL;

        dev_dbg(xudc->dev, "set address: %u\n", addr);

        xudc->dev_addr = addr;
        val = xudc_readl(xudc, CTRL);
        val &= ~(CTRL_DEVADDR_MASK);
        val |= CTRL_DEVADDR(addr);
        xudc_writel(xudc, val, CTRL);

        ep_ctx_write_devaddr(ep0->context, addr);

        return tegra_xudc_ep0_queue_status(xudc, set_address_complete);
}

static int tegra_xudc_ep0_standard_req(struct tegra_xudc *xudc,
                                      struct usb_ctrlrequest *ctrl)
{
        int ret;

        switch (ctrl->bRequest) {
        case USB_REQ_GET_STATUS:
                dev_dbg(xudc->dev, "USB_REQ_GET_STATUS\n");
                ret = tegra_xudc_ep0_get_status(xudc, ctrl);
                break;
        case USB_REQ_SET_ADDRESS:
                dev_dbg(xudc->dev, "USB_REQ_SET_ADDRESS\n");
                ret = tegra_xudc_ep0_set_address(xudc, ctrl);
                break;
        case USB_REQ_SET_SEL:
                dev_dbg(xudc->dev, "USB_REQ_SET_SEL\n");
                ret = tegra_xudc_ep0_set_sel(xudc, ctrl);
                break;
        case USB_REQ_SET_ISOCH_DELAY:
                dev_dbg(xudc->dev, "USB_REQ_SET_ISOCH_DELAY\n");
                ret = tegra_xudc_ep0_set_isoch_delay(xudc, ctrl);
                break;
        case USB_REQ_CLEAR_FEATURE:
        case USB_REQ_SET_FEATURE:
                dev_dbg(xudc->dev, "USB_REQ_CLEAR/SET_FEATURE\n");
                ret = tegra_xudc_ep0_set_feature(xudc, ctrl);
                break;
        case USB_REQ_SET_CONFIGURATION:
                dev_dbg(xudc->dev, "USB_REQ_SET_CONFIGURATION\n");
                /*
                 * In theory we need to clear RUN bit before status stage of
                 * deconfig request sent, but this seems to be causing problems.
                 * Clear RUN once all endpoints are disabled instead.
                 */
                fallthrough;
        default:
                ret = tegra_xudc_ep0_delegate_req(xudc, ctrl);
                break;
        }

        return ret;
}

static void tegra_xudc_handle_ep0_setup_packet(struct tegra_xudc *xudc,
                                               struct usb_ctrlrequest *ctrl,
                                               u16 seq_num)
{
        int ret;

        xudc->setup_seq_num = seq_num;

        /* Ensure EP0 is unhalted. */
        ep_unhalt(xudc, 0);

        /*
         * On Tegra210, setup packets with sequence numbers 0xfffe or 0xffff
         * are invalid.  Halt EP0 until we get a valid packet.
         */
        if (xudc->soc->invalid_seq_num &&
            (seq_num == 0xfffe || seq_num == 0xffff)) {
                dev_warn(xudc->dev, "invalid sequence number detected\n");
                ep_halt(xudc, 0);
                return;
        }

        if (ctrl->wLength)
                xudc->setup_state = (ctrl->bRequestType & USB_DIR_IN) ?
                        DATA_STAGE_XFER :  DATA_STAGE_RECV;
        else
                xudc->setup_state = STATUS_STAGE_XFER;

        if ((ctrl->bRequestType & USB_TYPE_MASK) == USB_TYPE_STANDARD)
                ret = tegra_xudc_ep0_standard_req(xudc, ctrl);
        else
                ret = tegra_xudc_ep0_delegate_req(xudc, ctrl);

        if (ret < 0) {
                dev_warn(xudc->dev, "setup request failed: %d\n", ret);
                xudc->setup_state = WAIT_FOR_SETUP;
                ep_halt(xudc, 0);
        }
}

static void tegra_xudc_handle_ep0_event(struct tegra_xudc *xudc,
                                        struct tegra_xudc_trb *event)
{
        struct usb_ctrlrequest *ctrl = (struct usb_ctrlrequest *)event;
        u16 seq_num = trb_read_seq_num(event);

        if (xudc->setup_state != WAIT_FOR_SETUP) {
                /*
                 * The controller is in the process of handling another
                 * setup request.  Queue subsequent requests and handle
                 * the last one once the controller reports a sequence
                 * number error.
                 */
                memcpy(&xudc->setup_packet.ctrl_req, ctrl, sizeof(*ctrl));
                xudc->setup_packet.seq_num = seq_num;
                xudc->queued_setup_packet = true;
        } else {
                tegra_xudc_handle_ep0_setup_packet(xudc, ctrl, seq_num);
        }
}

static struct tegra_xudc_request *
trb_to_request(struct tegra_xudc_ep *ep, struct tegra_xudc_trb *trb)
{
        struct tegra_xudc_request *req;

        list_for_each_entry(req, &ep->queue, list) {
                if (!req->trbs_queued)
                        break;

                if (trb_in_request(ep, req, trb))
                        return req;
        }

        return NULL;
}

static void tegra_xudc_handle_transfer_completion(struct tegra_xudc *xudc,
                                                  struct tegra_xudc_ep *ep,
                                                  struct tegra_xudc_trb *event)
{
        struct tegra_xudc_request *req;
        struct tegra_xudc_trb *trb;
        bool short_packet;

        short_packet = (trb_read_cmpl_code(event) ==
                        TRB_CMPL_CODE_SHORT_PACKET);

        trb = trb_phys_to_virt(ep, trb_read_data_ptr(event));
        req = trb_to_request(ep, trb);

        /*
         * TDs are complete on short packet or when the completed TRB is the
         * last TRB in the TD (the CHAIN bit is unset).
         */
        if (req && (short_packet || (!trb_read_chain(trb) &&
                (req->trbs_needed == req->trbs_queued)))) {
                struct tegra_xudc_trb *last = req->last_trb;
                unsigned int residual;

                residual = trb_read_transfer_len(event);
                req->usb_req.actual = req->usb_req.length - residual;

                dev_dbg(xudc->dev, "bytes transferred %u / %u\n",
                        req->usb_req.actual, req->usb_req.length);

                tegra_xudc_req_done(ep, req, 0);

                if (ep->desc && usb_endpoint_xfer_control(ep->desc))
                        tegra_xudc_ep0_req_done(xudc);

                /*
                 * Advance the dequeue pointer past the end of the current TD
                 * on short packet completion.
                 */
                if (short_packet) {
                        ep->deq_ptr = (last - ep->transfer_ring) + 1;
                        if (ep->deq_ptr == XUDC_TRANSFER_RING_SIZE - 1)
                                ep->deq_ptr = 0;
                }
        } else if (!req) {
                dev_warn(xudc->dev, "transfer event on dequeued request\n");
        }

        if (ep->desc)
                tegra_xudc_ep_kick_queue(ep);
}

static void tegra_xudc_handle_transfer_event(struct tegra_xudc *xudc,
                                             struct tegra_xudc_trb *event)
{
        unsigned int ep_index = trb_read_endpoint_id(event);
        struct tegra_xudc_ep *ep = &xudc->ep[ep_index];
        struct tegra_xudc_trb *trb;
        u16 comp_code;

        if (ep_ctx_read_state(ep->context) == EP_STATE_DISABLED) {
                dev_warn(xudc->dev, "transfer event on disabled EP %u\n",
                         ep_index);
                return;
        }

        /* Update transfer ring dequeue pointer. */
        trb = trb_phys_to_virt(ep, trb_read_data_ptr(event));
        comp_code = trb_read_cmpl_code(event);
        if (comp_code != TRB_CMPL_CODE_BABBLE_DETECTED_ERR) {
                ep->deq_ptr = (trb - ep->transfer_ring) + 1;

                if (ep->deq_ptr == XUDC_TRANSFER_RING_SIZE - 1)
                        ep->deq_ptr = 0;
                ep->ring_full = false;
        }

        switch (comp_code) {
        case TRB_CMPL_CODE_SUCCESS:
        case TRB_CMPL_CODE_SHORT_PACKET:
                tegra_xudc_handle_transfer_completion(xudc, ep, event);
                break;
        case TRB_CMPL_CODE_HOST_REJECTED:
                dev_info(xudc->dev, "stream rejected on EP %u\n", ep_index);

                ep->stream_rejected = true;
                break;
        case TRB_CMPL_CODE_PRIME_PIPE_RECEIVED:
                dev_info(xudc->dev, "prime pipe received on EP %u\n", ep_index);

                if (ep->stream_rejected) {
                        ep->stream_rejected = false;
                        /*
                         * An EP is stopped when a stream is rejected.  Wait
                         * for the EP to report that it is stopped and then
                         * un-stop it.
                         */
                        ep_wait_for_stopped(xudc, ep_index);
                }
                tegra_xudc_ep_ring_doorbell(ep);
                break;
        case TRB_CMPL_CODE_BABBLE_DETECTED_ERR:
                /*
                 * Wait for the EP to be stopped so the controller stops
                 * processing doorbells.
                 */
                ep_wait_for_stopped(xudc, ep_index);
                ep->enq_ptr = ep->deq_ptr;
                tegra_xudc_ep_nuke(ep, -EIO);
                fallthrough;
        case TRB_CMPL_CODE_STREAM_NUMP_ERROR:
        case TRB_CMPL_CODE_CTRL_DIR_ERR:
        case TRB_CMPL_CODE_INVALID_STREAM_TYPE_ERR:
        case TRB_CMPL_CODE_RING_UNDERRUN:
        case TRB_CMPL_CODE_RING_OVERRUN:
        case TRB_CMPL_CODE_ISOCH_BUFFER_OVERRUN:
        case TRB_CMPL_CODE_USB_TRANS_ERR:
        case TRB_CMPL_CODE_TRB_ERR:
                dev_err(xudc->dev, "completion error %#x on EP %u\n",
                        comp_code, ep_index);

                ep_halt(xudc, ep_index);
                break;
        case TRB_CMPL_CODE_CTRL_SEQNUM_ERR:
                dev_info(xudc->dev, "sequence number error\n");

                /*
                 * Kill any queued control request and skip to the last
                 * setup packet we received.
                 */
                tegra_xudc_ep_nuke(ep, -EINVAL);
                xudc->setup_state = WAIT_FOR_SETUP;
                if (!xudc->queued_setup_packet)
                        break;

                tegra_xudc_handle_ep0_setup_packet(xudc,
                                                   &xudc->setup_packet.ctrl_req,
                                                   xudc->setup_packet.seq_num);
                xudc->queued_setup_packet = false;
                break;
        case TRB_CMPL_CODE_STOPPED:
                dev_dbg(xudc->dev, "stop completion code on EP %u\n",
                        ep_index);

                /* Disconnected. */
                tegra_xudc_ep_nuke(ep, -ECONNREFUSED);
                break;
        default:
                dev_dbg(xudc->dev, "completion event %#x on EP %u\n",
                        comp_code, ep_index);
                break;
        }
}

static void tegra_xudc_reset(struct tegra_xudc *xudc)
{
        struct tegra_xudc_ep *ep0 = &xudc->ep[0];
        dma_addr_t deq_ptr;
        unsigned int i;

        xudc->setup_state = WAIT_FOR_SETUP;
        xudc->device_state = USB_STATE_DEFAULT;
        usb_gadget_set_state(&xudc->gadget, xudc->device_state);

        ep_unpause_all(xudc);

        for (i = 0; i < ARRAY_SIZE(xudc->ep); i++)
                tegra_xudc_ep_nuke(&xudc->ep[i], -ESHUTDOWN);

        /*
         * Reset sequence number and dequeue pointer to flush the transfer
         * ring.
         */
        ep0->deq_ptr = ep0->enq_ptr;
        ep0->ring_full = false;

        xudc->setup_seq_num = 0;
        xudc->queued_setup_packet = false;

        ep_ctx_write_seq_num(ep0->context, xudc->setup_seq_num);

        deq_ptr = trb_virt_to_phys(ep0, &ep0->transfer_ring[ep0->deq_ptr]);

        if (!dma_mapping_error(xudc->dev, deq_ptr)) {
                ep_ctx_write_deq_ptr(ep0->context, deq_ptr);
                ep_ctx_write_dcs(ep0->context, ep0->pcs);
        }

        ep_unhalt_all(xudc);
        ep_reload(xudc, 0);
        ep_unpause(xudc, 0);
}

static void tegra_xudc_port_connect(struct tegra_xudc *xudc)
{
        struct tegra_xudc_ep *ep0 = &xudc->ep[0];
        u16 maxpacket;
        u32 val;

        val = (xudc_readl(xudc, PORTSC) & PORTSC_PS_MASK) >> PORTSC_PS_SHIFT;
        switch (val) {
        case PORTSC_PS_LS:
                xudc->gadget.speed = USB_SPEED_LOW;
                break;
        case PORTSC_PS_FS:
                xudc->gadget.speed = USB_SPEED_FULL;
                break;
        case PORTSC_PS_HS:
                xudc->gadget.speed = USB_SPEED_HIGH;
                break;
        case PORTSC_PS_SS:
                xudc->gadget.speed = USB_SPEED_SUPER;
                break;
        default:
                xudc->gadget.speed = USB_SPEED_UNKNOWN;
                break;
        }

        xudc->device_state = USB_STATE_DEFAULT;
        usb_gadget_set_state(&xudc->gadget, xudc->device_state);

        xudc->setup_state = WAIT_FOR_SETUP;

        if (xudc->gadget.speed == USB_SPEED_SUPER)
                maxpacket = 512;
        else
                maxpacket = 64;

        ep_ctx_write_max_packet_size(ep0->context, maxpacket);
        tegra_xudc_ep0_desc.wMaxPacketSize = cpu_to_le16(maxpacket);
        usb_ep_set_maxpacket_limit(&ep0->usb_ep, maxpacket);

        if (!xudc->soc->u1_enable) {
                val = xudc_readl(xudc, PORTPM);
                val &= ~(PORTPM_U1TIMEOUT_MASK);
                xudc_writel(xudc, val, PORTPM);
        }

        if (!xudc->soc->u2_enable) {
                val = xudc_readl(xudc, PORTPM);
                val &= ~(PORTPM_U2TIMEOUT_MASK);
                xudc_writel(xudc, val, PORTPM);
        }

        if (xudc->gadget.speed <= USB_SPEED_HIGH) {
                val = xudc_readl(xudc, PORTPM);
                val &= ~(PORTPM_L1S_MASK);
                if (xudc->soc->lpm_enable)
                        val |= PORTPM_L1S(PORTPM_L1S_ACCEPT);
                else
                        val |= PORTPM_L1S(PORTPM_L1S_NYET);
                xudc_writel(xudc, val, PORTPM);
        }

        val = xudc_readl(xudc, ST);
        if (val & ST_RC)
                xudc_writel(xudc, ST_RC, ST);
}

static void tegra_xudc_port_disconnect(struct tegra_xudc *xudc)
{
        tegra_xudc_reset(xudc);

        if (xudc->driver && xudc->driver->disconnect) {
                spin_unlock(&xudc->lock);
                xudc->driver->disconnect(&xudc->gadget);
                spin_lock(&xudc->lock);
        }

        xudc->device_state = USB_STATE_NOTATTACHED;
        usb_gadget_set_state(&xudc->gadget, xudc->device_state);

        complete(&xudc->disconnect_complete);
}

static void tegra_xudc_port_reset(struct tegra_xudc *xudc)
{
        tegra_xudc_reset(xudc);

        if (xudc->driver) {
                spin_unlock(&xudc->lock);
                usb_gadget_udc_reset(&xudc->gadget, xudc->driver);
                spin_lock(&xudc->lock);
        }

        tegra_xudc_port_connect(xudc);
}

static void tegra_xudc_port_suspend(struct tegra_xudc *xudc)
{
        dev_dbg(xudc->dev, "port suspend\n");

        xudc->resume_state = xudc->device_state;
        xudc->device_state = USB_STATE_SUSPENDED;
        usb_gadget_set_state(&xudc->gadget, xudc->device_state);

        if (xudc->driver->suspend) {
                spin_unlock(&xudc->lock);
                xudc->driver->suspend(&xudc->gadget);
                spin_lock(&xudc->lock);
        }
}

static void tegra_xudc_port_resume(struct tegra_xudc *xudc)
{
        dev_dbg(xudc->dev, "port resume\n");

        tegra_xudc_resume_device_state(xudc);

        if (xudc->driver->resume) {
                spin_unlock(&xudc->lock);
                xudc->driver->resume(&xudc->gadget);
                spin_lock(&xudc->lock);
        }
}

static inline void clear_port_change(struct tegra_xudc *xudc, u32 flag)
{
        u32 val;

        val = xudc_readl(xudc, PORTSC);
        val &= ~PORTSC_CHANGE_MASK;
        val |= flag;
        xudc_writel(xudc, val, PORTSC);
}

static void __tegra_xudc_handle_port_status(struct tegra_xudc *xudc)
{
        u32 portsc, porthalt;

        porthalt = xudc_readl(xudc, PORTHALT);
        if ((porthalt & PORTHALT_STCHG_REQ) &&
            (porthalt & PORTHALT_HALT_LTSSM)) {
                dev_dbg(xudc->dev, "STCHG_REQ, PORTHALT = %#x\n", porthalt);
                porthalt &= ~PORTHALT_HALT_LTSSM;
                xudc_writel(xudc, porthalt, PORTHALT);
        }

        portsc = xudc_readl(xudc, PORTSC);
        if ((portsc & PORTSC_PRC) && (portsc & PORTSC_PR)) {
                dev_dbg(xudc->dev, "PRC, PR, PORTSC = %#x\n", portsc);
                clear_port_change(xudc, PORTSC_PRC | PORTSC_PED);
#define TOGGLE_VBUS_WAIT_MS 100
                if (xudc->soc->port_reset_quirk) {
                        schedule_delayed_work(&xudc->port_reset_war_work,
                                msecs_to_jiffies(TOGGLE_VBUS_WAIT_MS));
                        xudc->wait_for_sec_prc = 1;
                }
        }

        if ((portsc & PORTSC_PRC) && !(portsc & PORTSC_PR)) {
                dev_dbg(xudc->dev, "PRC, Not PR, PORTSC = %#x\n", portsc);
                clear_port_change(xudc, PORTSC_PRC | PORTSC_PED);
                tegra_xudc_port_reset(xudc);
                cancel_delayed_work(&xudc->port_reset_war_work);
                xudc->wait_for_sec_prc = 0;
        }

        portsc = xudc_readl(xudc, PORTSC);
        if (portsc & PORTSC_WRC) {
                dev_dbg(xudc->dev, "WRC, PORTSC = %#x\n", portsc);
                clear_port_change(xudc, PORTSC_WRC | PORTSC_PED);
                if (!(xudc_readl(xudc, PORTSC) & PORTSC_WPR))
                        tegra_xudc_port_reset(xudc);
        }