/*
 * Copyright (c) 2023 Nordic Semiconductor ASA
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#include "udc_common.h"
#include "udc_dwc2.h"
#include "udc_dwc2_vendor_quirks.h"

#include <string.h>
#include <stdio.h>

#include <zephyr/kernel.h>
#include <zephyr/devicetree.h>
#include <zephyr/sys/util.h>
#include <zephyr/sys/sys_io.h>
#include <zephyr/sys/byteorder.h>
#include <zephyr/drivers/usb/udc.h>
#include <zephyr/usb/usb_ch9.h>
#include <usb_dwc2_hw.h>

#include <zephyr/logging/log.h>
LOG_MODULE_REGISTER(udc_dwc2, CONFIG_UDC_DRIVER_LOG_LEVEL);

enum dwc2_drv_event_type {
	/* Trigger next transfer, must not be used for control OUT */
	DWC2_DRV_EVT_XFER,
	/* Setup packet received */
	DWC2_DRV_EVT_SETUP,
	/* OUT transaction for specific endpoint is finished */
	DWC2_DRV_EVT_DOUT,
	/* IN transaction for specific endpoint is finished */
	DWC2_DRV_EVT_DIN,
};

struct dwc2_drv_event {
	const struct device *dev;
	enum dwc2_drv_event_type type;
	uint32_t bcnt;
	uint8_t ep;
};

K_MSGQ_DEFINE(drv_msgq, sizeof(struct dwc2_drv_event),
	      CONFIG_UDC_DWC2_MAX_QMESSAGES, sizeof(void *));


/* Minimum RX FIFO size in 32-bit words considering the largest used OUT packet
 * of 512 bytes. The value must be adjusted according to the number of OUT
 * endpoints.
 */
#define UDC_DWC2_GRXFSIZ_DEFAULT	(15U + 512U/4U)

/* TX FIFO0 depth in 32-bit words (used by control IN endpoint) */
#define UDC_DWC2_FIFO0_DEPTH		16U

/* Number of endpoints supported by the driver.
 * This must be equal to or greater than the number supported by the hardware.
 * (FIXME)
 */
#define UDC_DWC2_DRV_EP_NUM		8

/* Get Data FIFO access register */
#define UDC_DWC2_EP_FIFO(base, idx)	((mem_addr_t)base + 0x1000 * (idx + 1))

/* Driver private data per instance */
struct udc_dwc2_data {
	struct k_thread thread_data;
	uint32_t ghwcfg1;
	uint32_t enumspd;
	uint32_t txf_set;
	uint32_t grxfsiz;
	uint32_t dfifodepth;
	uint32_t max_xfersize;
	uint32_t max_pktcnt;
	uint32_t tx_len[16];
	unsigned int dynfifosizing : 1;
	/* Number of endpoints in addition to control endpoint */
	uint8_t numdeveps;
	/* Number of IN endpoints including control endpoint */
	uint8_t ineps;
	/* Number of OUT endpoints including control endpoint */
	uint8_t outeps;
	uint8_t setup[8];
};

#if defined(CONFIG_PINCTRL)
#include <zephyr/drivers/pinctrl.h>

static int dwc2_init_pinctrl(const struct device *dev)
{
	const struct udc_dwc2_config *const config = dev->config;
	const struct pinctrl_dev_config *const pcfg = config->pcfg;
	int ret = 0;

	if (pcfg == NULL) {
		LOG_INF("Skip pinctrl configuration");
		return 0;
	}

	ret = pinctrl_apply_state(pcfg, PINCTRL_STATE_DEFAULT);
	if (ret) {
		LOG_ERR("Failed to apply default pinctrl state (%d)", ret);
	}

	LOG_DBG("Apply pinctrl");

	return ret;
}
#else
static int dwc2_init_pinctrl(const struct device *dev)
{
	ARG_UNUSED(dev);

	return 0;
}
#endif

static inline struct usb_dwc2_reg *dwc2_get_base(const struct device *dev)
{
	const struct udc_dwc2_config *const config = dev->config;

	return config->base;
}

/* Get DOEPCTLn or DIEPCTLn register address */
static mem_addr_t dwc2_get_dxepctl_reg(const struct device *dev, const uint8_t ep)
{
	struct usb_dwc2_reg *const base = dwc2_get_base(dev);
	uint8_t ep_idx = USB_EP_GET_IDX(ep);

	if (USB_EP_DIR_IS_OUT(ep)) {
		return (mem_addr_t)&base->out_ep[ep_idx].doepctl;
	} else {
		return (mem_addr_t)&base->in_ep[ep_idx].diepctl;
	}
}

/* Get available FIFO space in bytes */
static uint32_t dwc2_ftx_avail(const struct device *dev, const uint32_t idx)
{
	struct usb_dwc2_reg *const base = dwc2_get_base(dev);
	mem_addr_t reg = (mem_addr_t)&base->in_ep[idx].dtxfsts;
	uint32_t dtxfsts;

	dtxfsts = sys_read32(reg);

	return usb_dwc2_get_dtxfsts_ineptxfspcavail(dtxfsts) * 4;
}

static uint32_t dwc2_get_iept_pktctn(const struct device *dev, const uint32_t idx)
{
	struct udc_dwc2_data *const priv = udc_get_private(dev);

	if (idx == 0) {
		return usb_dwc2_get_dieptsiz0_pktcnt(UINT32_MAX);
	} else {
		return priv->max_pktcnt;
	}
}

static uint32_t dwc2_get_iept_xfersize(const struct device *dev, const uint32_t idx)
{
	struct udc_dwc2_data *const priv = udc_get_private(dev);

	if (idx == 0) {
		return usb_dwc2_get_dieptsiz0_xfersize(UINT32_MAX);
	} else {
		return priv->max_xfersize;
	}
}

static void dwc2_flush_rx_fifo(const struct device *dev)
{
	struct usb_dwc2_reg *const base = dwc2_get_base(dev);
	mem_addr_t grstctl_reg = (mem_addr_t)&base->grstctl;

	sys_write32(USB_DWC2_GRSTCTL_RXFFLSH, grstctl_reg);
	while (sys_read32(grstctl_reg) & USB_DWC2_GRSTCTL_RXFFLSH) {
	}
}

static void dwc2_flush_tx_fifo(const struct device *dev, const uint8_t idx)
{
	struct usb_dwc2_reg *const base = dwc2_get_base(dev);
	mem_addr_t grstctl_reg = (mem_addr_t)&base->grstctl;
	/* TODO: use dwc2_get_dxepctl_reg() */
	mem_addr_t diepctl_reg = (mem_addr_t)&base->in_ep[idx].diepctl;
	uint32_t grstctl;
	uint32_t fnum;

	fnum = usb_dwc2_get_depctl_txfnum(sys_read32(diepctl_reg));
	grstctl = usb_dwc2_set_grstctl_txfnum(fnum) | USB_DWC2_GRSTCTL_TXFFLSH;

	sys_write32(grstctl, grstctl_reg);
	while (sys_read32(grstctl_reg) & USB_DWC2_GRSTCTL_TXFFLSH) {
	}
}

/* Return TX FIFOi depth in 32-bit words (i = f_idx + 1) */
static uint32_t dwc2_get_txfdep(const struct device *dev, const uint32_t f_idx)
{
	struct usb_dwc2_reg *const base = dwc2_get_base(dev);
	uint32_t dieptxf;

	dieptxf = sys_read32((mem_addr_t)&base->dieptxf[f_idx]);

	return usb_dwc2_get_dieptxf_inepntxfdep(dieptxf);
}

/* Return TX FIFOi address (i = f_idx + 1) */
static uint32_t dwc2_get_txfaddr(const struct device *dev, const uint32_t f_idx)
{
	struct usb_dwc2_reg *const base = dwc2_get_base(dev);
	uint32_t dieptxf;

	dieptxf = sys_read32((mem_addr_t)&base->dieptxf[f_idx]);

	return  usb_dwc2_get_dieptxf_inepntxfstaddr(dieptxf);
}

/* Set TX FIFOi address and depth (i = f_idx + 1) */
static void dwc2_set_txf(const struct device *dev, const uint32_t f_idx,
			 const uint32_t dep, const uint32_t addr)
{
	struct usb_dwc2_reg *const base = dwc2_get_base(dev);
	uint32_t dieptxf;

	dieptxf = usb_dwc2_set_dieptxf_inepntxfdep(dep) |
		  usb_dwc2_set_dieptxf_inepntxfstaddr(addr);

	sys_write32(dieptxf, (mem_addr_t)&base->dieptxf[f_idx]);
}

/* Enable/disable endpoint interrupt */
static void dwc2_set_epint(const struct device *dev,
			   struct udc_ep_config *const cfg, const bool enabled)
{
	struct usb_dwc2_reg *const base = dwc2_get_base(dev);
	mem_addr_t reg = (mem_addr_t)&base->daintmsk;
	uint8_t ep_idx = USB_EP_GET_IDX(cfg->addr);
	uint32_t epmsk;

	if (USB_EP_DIR_IS_IN(cfg->addr)) {
		epmsk = USB_DWC2_DAINT_INEPINT(ep_idx);
	} else {
		epmsk = USB_DWC2_DAINT_OUTEPINT(ep_idx);
	}

	if (enabled) {
		sys_set_bits(reg, epmsk);
	} else {
		sys_clear_bits(reg, epmsk);
	}
}

/* Can be called from ISR context */
static int dwc2_tx_fifo_write(const struct device *dev,
			      struct udc_ep_config *const cfg, struct net_buf *const buf)
{
	struct usb_dwc2_reg *const base = dwc2_get_base(dev);
	struct udc_dwc2_data *const priv = udc_get_private(dev);
	uint8_t ep_idx = USB_EP_GET_IDX(cfg->addr);

	mem_addr_t dieptsiz_reg = (mem_addr_t)&base->in_ep[ep_idx].dieptsiz;
	/* TODO: use dwc2_get_dxepctl_reg() */
	mem_addr_t diepctl_reg = (mem_addr_t)&base->in_ep[ep_idx].diepctl;

	uint32_t max_xfersize, max_pktcnt, pktcnt, spcavail;
	const size_t d = sizeof(uint32_t);
	unsigned int key;
	uint32_t len;

	spcavail = dwc2_ftx_avail(dev, ep_idx);
	/* Round down to multiple of endpoint MPS */
	spcavail -= spcavail % cfg->mps;
	/*
	 * Here, the available space should be equal to the FIFO space
	 * assigned/configured for that endpoint because we do not schedule another
	 * transfer until the previous one has not finished. For simplicity,
	 * we only check that the available space is not less than the endpoint
	 * MPS.
	 */
	if (spcavail < cfg->mps) {
		LOG_ERR("ep 0x%02x FIFO space is too low, %u (%u)",
			cfg->addr, spcavail, dwc2_ftx_avail(dev, ep_idx));
		return -EAGAIN;
	}

	len = MIN(buf->len, spcavail);

	if (len != 0U) {
		max_pktcnt = dwc2_get_iept_pktctn(dev, ep_idx);
		max_xfersize = dwc2_get_iept_xfersize(dev, ep_idx);

		if (len > max_xfersize) {
			/*
			 * Avoid short packets if the transfer size cannot be
			 * handled in one set.
			 */
			len = ROUND_DOWN(max_xfersize, cfg->mps);
		}

		/*
		 * Determine the number of packets for the current transfer;
		 * if the pktcnt is too large, truncate the actual transfer length.
		 */
		pktcnt = DIV_ROUND_UP(len, cfg->mps);
		if (pktcnt > max_pktcnt) {
			pktcnt = max_pktcnt;
			len = pktcnt * cfg->mps;
		}
	} else {
		/* ZLP */
		pktcnt = 1U;
	}

	LOG_DBG("Prepare ep 0x%02x xfer len %u pktcnt %u spcavail %u",
		cfg->addr, len, pktcnt, spcavail);
	priv->tx_len[ep_idx] = len;

	/* Lock and write to endpoint FIFO */
	key = irq_lock();

	/* Set number of packets and transfer size */
	sys_write32((pktcnt << USB_DWC2_DEPTSIZN_PKTCNT_POS) | len, dieptsiz_reg);

	/* Clear NAK and set endpoint enable */
	sys_set_bits(diepctl_reg, USB_DWC2_DEPCTL_EPENA | USB_DWC2_DEPCTL_CNAK);

	/* FIFO access is always in 32-bit words */

	for (uint32_t i = 0UL; i < len; i += d) {
		uint32_t val = buf->data[i];

		if (i + 1 < len) {
			val |= ((uint32_t)buf->data[i + 1UL]) << 8;
		}
		if (i + 2 < len) {
			val |= ((uint32_t)buf->data[i + 2UL]) << 16;
		}
		if (i + 3 < len) {
			val |= ((uint32_t)buf->data[i + 3UL]) << 24;
		}

		sys_write32(val, UDC_DWC2_EP_FIFO(base, ep_idx));
	}

	irq_unlock(key);

	return 0;
}

static inline int dwc2_read_fifo(const struct device *dev, const uint8_t ep,
				 struct net_buf *const buf, const size_t size)
{
	struct usb_dwc2_reg *const base = dwc2_get_base(dev);
	size_t len = MIN(size, net_buf_tailroom(buf));
	const size_t d = sizeof(uint32_t);

	/* FIFO access is always in 32-bit words */

	for (uint32_t n = 0; n < (len / d); n++) {
		net_buf_add_le32(buf, sys_read32(UDC_DWC2_EP_FIFO(base, ep)));
	}

	if (len % d) {
		uint8_t r[4];

		/* Get the remaining */
		sys_put_le32(sys_read32(UDC_DWC2_EP_FIFO(base, ep)), r);
		for (uint32_t i = 0U; i < (len % d); i++) {
			net_buf_add_u8(buf, r[i]);
		}
	}

	if (unlikely(size > len)) {
		for (uint32_t n = 0; n < DIV_ROUND_UP(size - len, d); n++) {
			(void)sys_read32(UDC_DWC2_EP_FIFO(base, ep));
		}
	}

	return 0;
}

/* Can be called from ISR and we call it only when there is a buffer in the queue */
static void dwc2_prep_rx(const struct device *dev,
			 struct udc_ep_config *const cfg, const bool ncnak)
{
	struct usb_dwc2_reg *const base = dwc2_get_base(dev);
	uint8_t ep_idx = USB_EP_GET_IDX(cfg->addr);
	mem_addr_t doeptsiz_reg = (mem_addr_t)&base->out_ep[ep_idx].doeptsiz;
	mem_addr_t doepctl_reg = dwc2_get_dxepctl_reg(dev, ep_idx);
	uint32_t doeptsiz;

	doeptsiz = (1 << USB_DWC2_DOEPTSIZ0_PKTCNT_POS) | cfg->mps;
	if (cfg->addr == USB_CONTROL_EP_OUT) {
		doeptsiz |= (1 << USB_DWC2_DOEPTSIZ0_SUPCNT_POS);
	}

	sys_write32(doeptsiz, doeptsiz_reg);

	if (ncnak) {
		sys_set_bits(doepctl_reg, USB_DWC2_DEPCTL_EPENA);
	} else {
		sys_set_bits(doepctl_reg, USB_DWC2_DEPCTL_EPENA | USB_DWC2_DEPCTL_CNAK);
	}

	LOG_INF("Prepare RX 0x%02x doeptsiz 0x%x", cfg->addr, doeptsiz);
}

static void dwc2_handle_xfer_next(const struct device *dev,
				  struct udc_ep_config *const cfg)
{
	struct net_buf *buf;

	buf = udc_buf_peek(dev, cfg->addr);
	if (buf == NULL) {
		return;
	}

	if (USB_EP_DIR_IS_OUT(cfg->addr)) {
		dwc2_prep_rx(dev, cfg, 0);
	} else {
		if (dwc2_tx_fifo_write(dev, cfg, buf)) {
			LOG_ERR("Failed to start write to TX FIFO, ep 0x%02x",
				cfg->addr);
		}
	}

	udc_ep_set_busy(dev, cfg->addr, true);
}

static int dwc2_ctrl_feed_dout(const struct device *dev, const size_t length)
{
	struct net_buf *buf;

	buf = udc_ctrl_alloc(dev, USB_CONTROL_EP_OUT, length);
	if (buf == NULL) {
		return -ENOMEM;
	}

	udc_buf_put(udc_get_ep_cfg(dev, USB_CONTROL_EP_OUT), buf);
	dwc2_prep_rx(dev, udc_get_ep_cfg(dev, USB_CONTROL_EP_OUT), 0);
	LOG_DBG("feed buf %p", buf);

	return 0;
}

static int dwc2_handle_evt_setup(const struct device *dev)
{
	struct udc_dwc2_data *const priv = udc_get_private(dev);
	struct net_buf *buf;
	int err;

	buf = udc_buf_get(dev, USB_CONTROL_EP_OUT);
	if (buf == NULL) {
		LOG_ERR("No buffer queued for control ep");
		return -ENODATA;
	}

	net_buf_add_mem(buf, priv->setup, sizeof(priv->setup));
	udc_ep_buf_set_setup(buf);
	LOG_HEXDUMP_DBG(buf->data, buf->len, "setup");

	/* Update to next stage of control transfer */
	udc_ctrl_update_stage(dev, buf);

	/* We always allocate and feed buffer large enough for a setup packet. */

	if (udc_ctrl_stage_is_data_out(dev)) {
		/*  Allocate and feed buffer for data OUT stage */
		LOG_DBG("s:%p|feed for -out-", buf);

		err = dwc2_ctrl_feed_dout(dev, udc_data_stage_length(buf));
		if (err == -ENOMEM) {
			err = udc_submit_ep_event(dev, buf, err);
		}
	} else if (udc_ctrl_stage_is_data_in(dev)) {
		LOG_DBG("s:%p|feed for -in-status", buf);

		err = dwc2_ctrl_feed_dout(dev, 8);
		if (err == -ENOMEM) {
			err = udc_submit_ep_event(dev, buf, err);
		}

		err = udc_ctrl_submit_s_in_status(dev);
	} else {
		LOG_DBG("s:%p|feed >setup", buf);

		err = dwc2_ctrl_feed_dout(dev, 8);
		if (err == -ENOMEM) {
			err = udc_submit_ep_event(dev, buf, err);
		}

		err = udc_ctrl_submit_s_status(dev);
	}

	return err;
}

static inline int dwc2_handle_evt_dout(const struct device *dev,
				       struct udc_ep_config *const cfg)
{
	struct net_buf *buf;
	int err = 0;

	buf = udc_buf_get(dev, cfg->addr);
	if (buf == NULL) {
		LOG_ERR("No buffer queued for control ep");
		return -ENODATA;
	}

	udc_ep_set_busy(dev, cfg->addr, false);

	if (cfg->addr == USB_CONTROL_EP_OUT) {
		if (udc_ctrl_stage_is_status_out(dev)) {
			/* s-in-status finished */
			LOG_DBG("dout:%p| status, feed >s", buf);

			/* Feed a buffer for the next setup packet */
			err = dwc2_ctrl_feed_dout(dev, 8);
			if (err == -ENOMEM) {
				err = udc_submit_ep_event(dev, buf, err);
			}

			/* Status stage finished, notify upper layer */
			udc_ctrl_submit_status(dev, buf);
		} else {
			/*
			 * For all other cases we feed with a buffer
			 * large enough for setup packet.
			 */
			LOG_DBG("dout:%p| data, feed >s", buf);

			err = dwc2_ctrl_feed_dout(dev, 8);
			if (err == -ENOMEM) {
				err = udc_submit_ep_event(dev, buf, err);
			}
		}

		/* Update to next stage of control transfer */
		udc_ctrl_update_stage(dev, buf);

		if (udc_ctrl_stage_is_status_in(dev)) {
			err = udc_ctrl_submit_s_out_status(dev, buf);
		}
	} else {
		err = udc_submit_ep_event(dev, buf, 0);
	}

	return err;
}

static int dwc2_handle_evt_din(const struct device *dev,
			       struct udc_ep_config *const cfg)
{
	struct net_buf *buf;

	buf = udc_buf_peek(dev, cfg->addr);
	if (buf == NULL) {
		LOG_ERR("No buffer for ep 0x%02x", cfg->addr);
		udc_submit_event(dev, UDC_EVT_ERROR, -ENOBUFS);
		return -ENOBUFS;
	}

	if (buf->len) {
		/* Looks like we failed to continue in ISR, retry */
		return dwc2_tx_fifo_write(dev, cfg, buf);
	}

	if (cfg->addr == USB_CONTROL_EP_IN && udc_ep_buf_has_zlp(buf)) {
		udc_ep_buf_clear_zlp(buf);
		return dwc2_tx_fifo_write(dev, cfg, buf);
	}

	buf = udc_buf_get(dev, cfg->addr);
	udc_ep_set_busy(dev, cfg->addr, false);

	if (cfg->addr == USB_CONTROL_EP_IN) {
		if (udc_ctrl_stage_is_status_in(dev) ||
		    udc_ctrl_stage_is_no_data(dev)) {
			/* Status stage finished, notify upper layer */
			udc_ctrl_submit_status(dev, buf);
		}

		/* Update to next stage of control transfer */
		udc_ctrl_update_stage(dev, buf);

		if (udc_ctrl_stage_is_status_out(dev)) {
			/*
			 * IN transfer finished, release buffer,
			 * control OUT buffer should be already fed.
			 */
			net_buf_unref(buf);
		}

		return 0;
	}

	return udc_submit_ep_event(dev, buf, 0);
}

static ALWAYS_INLINE void dwc2_thread_handler(void *const arg)
{
	const struct device *dev = (const struct device *)arg;
	struct udc_ep_config *ep_cfg;
	struct dwc2_drv_event evt;

	/* This is the bottom-half of the ISR handler and the place where
	 * a new transfer can be fed.
	 */
	k_msgq_get(&drv_msgq, &evt, K_FOREVER);
	ep_cfg = udc_get_ep_cfg(dev, evt.ep);

	switch (evt.type) {
	case DWC2_DRV_EVT_XFER:
		LOG_DBG("New transfer in the queue");
		break;
	case DWC2_DRV_EVT_SETUP:
		LOG_DBG("SETUP event");
		dwc2_handle_evt_setup(dev);
		break;
	case DWC2_DRV_EVT_DOUT:
		LOG_DBG("DOUT event ep 0x%02x", ep_cfg->addr);
		dwc2_handle_evt_dout(dev, ep_cfg);
		break;
	case DWC2_DRV_EVT_DIN:
		LOG_DBG("DIN event");
		dwc2_handle_evt_din(dev, ep_cfg);
		break;
	}

	if (ep_cfg->addr != USB_CONTROL_EP_OUT && !udc_ep_is_busy(dev, ep_cfg->addr)) {
		dwc2_handle_xfer_next(dev, ep_cfg);
	} else {
		LOG_DBG("ep 0x%02x busy", ep_cfg->addr);
	}
}

static void dwc2_on_bus_reset(const struct device *dev)
{
	struct usb_dwc2_reg *const base = dwc2_get_base(dev);
	struct udc_dwc2_data *const priv = udc_get_private(dev);

	/* Set the NAK bit for all OUT endpoints */
	for (uint8_t i = 0U; i < priv->numdeveps; i++) {
		uint32_t epdir = usb_dwc2_get_ghwcfg1_epdir(priv->ghwcfg1, i);
		mem_addr_t doepctl_reg;

		LOG_DBG("ep 0x%02x EPDIR %u", i, epdir);
		if (epdir == USB_DWC2_GHWCFG1_EPDIR_OUT ||
		    epdir == USB_DWC2_GHWCFG1_EPDIR_BDIR) {
			doepctl_reg = dwc2_get_dxepctl_reg(dev, i);
			sys_write32(USB_DWC2_DEPCTL_SNAK, doepctl_reg);
		}
	}

	sys_write32(0UL, (mem_addr_t)&base->doepmsk);
	sys_set_bits((mem_addr_t)&base->gintmsk, USB_DWC2_GINTSTS_RXFLVL);
	sys_set_bits((mem_addr_t)&base->diepmsk, USB_DWC2_DIEPINT_XFERCOMPL);

	/* Clear device address during reset. */
	sys_clear_bits((mem_addr_t)&base->dcfg, USB_DWC2_DCFG_DEVADDR_MASK);
}

static void dwc2_handle_enumdone(const struct device *dev)
{
	struct usb_dwc2_reg *const base = dwc2_get_base(dev);
	struct udc_dwc2_data *const priv = udc_get_private(dev);
	uint32_t dsts;

	dsts = sys_read32((mem_addr_t)&base->dsts);
	priv->enumspd = usb_dwc2_get_dsts_enumspd(dsts);
}

static inline int dwc2_read_fifo_setup(const struct device *dev)
{
	struct usb_dwc2_reg *const base = dwc2_get_base(dev);
	struct udc_dwc2_data *const priv = udc_get_private(dev);

	/* FIFO access is always in 32-bit words */

	/*
	 * We store the setup packet temporarily in the driver's private data
	 * because there is always a race risk after the status stage OUT
	 * packet from the host and the new setup packet. This is fine in
	 * bottom-half processing because the events arrive in a queue and
	 * there will be a next net_buf for the setup packet.
	 */
	sys_put_le32(sys_read32(UDC_DWC2_EP_FIFO(base, 0)), priv->setup);
	sys_put_le32(sys_read32(UDC_DWC2_EP_FIFO(base, 0)), &priv->setup[4]);

	return 0;
}

static inline void dwc2_handle_rxflvl(const struct device *dev)
{
	struct usb_dwc2_reg *const base = dwc2_get_base(dev);
	struct udc_ep_config *ep_cfg;
	struct dwc2_drv_event evt;
	struct net_buf *buf;
	uint32_t grxstsp;
	uint32_t pktsts;

	grxstsp = sys_read32((mem_addr_t)&base->grxstsp);
	evt.ep = usb_dwc2_get_grxstsp_epnum(grxstsp);
	evt.bcnt = usb_dwc2_get_grxstsp_bcnt(grxstsp);
	pktsts = usb_dwc2_get_grxstsp_pktsts(grxstsp);

	LOG_DBG("ep 0x%02x: pktsts %u, bcnt %u", evt.ep, pktsts, evt.bcnt);

	switch (pktsts) {
	case USB_DWC2_GRXSTSR_PKTSTS_SETUP:
		evt.type = DWC2_DRV_EVT_SETUP;

		__ASSERT(evt.bcnt == 8, "Incorrect setup packet length");
		dwc2_read_fifo_setup(dev);

		k_msgq_put(&drv_msgq, &evt, K_NO_WAIT);
		break;
	case USB_DWC2_GRXSTSR_PKTSTS_OUT_DATA:
		evt.type = DWC2_DRV_EVT_DOUT;
		ep_cfg = udc_get_ep_cfg(dev, evt.ep);

		buf = udc_buf_peek(dev, ep_cfg->addr);
		if (buf == NULL) {
			LOG_ERR("No buffer for ep 0x%02x", ep_cfg->addr);
			udc_submit_event(dev, UDC_EVT_ERROR, -ENOBUFS);
			break;
		}

		dwc2_read_fifo(dev, USB_CONTROL_EP_OUT, buf, evt.bcnt);

		if (net_buf_tailroom(buf) && evt.bcnt == ep_cfg->mps) {
			dwc2_prep_rx(dev, ep_cfg, 0);
		} else {
			k_msgq_put(&drv_msgq, &evt, K_NO_WAIT);
		}

		break;
	case USB_DWC2_GRXSTSR_PKTSTS_OUT_DATA_DONE:
	case USB_DWC2_GRXSTSR_PKTSTS_SETUP_DONE:
		LOG_DBG("RX pktsts DONE");
		break;
	default:
		break;
	}
}

static inline void dwc2_handle_xfercompl(const struct device *dev,
					 const uint8_t ep_idx)
{
	struct udc_dwc2_data *const priv = udc_get_private(dev);
	struct udc_ep_config *ep_cfg;
	struct dwc2_drv_event evt;
	struct net_buf *buf;

	ep_cfg = udc_get_ep_cfg(dev, ep_idx | USB_EP_DIR_IN);
	buf = udc_buf_peek(dev, ep_cfg->addr);
	if (buf == NULL) {
		udc_submit_event(dev, UDC_EVT_ERROR, -ENOBUFS);
		return;
	}

	net_buf_pull(buf, priv->tx_len[ep_idx]);
	if (buf->len  && dwc2_tx_fifo_write(dev, ep_cfg, buf) == 0) {
		return;
	}

	evt.dev = dev;
	evt.ep = ep_cfg->addr;
	evt.type = DWC2_DRV_EVT_DIN;
	k_msgq_put(&drv_msgq, &evt, K_NO_WAIT);
}

static inline void dwc2_handle_iepint(const struct device *dev)
{
	struct usb_dwc2_reg *const base = dwc2_get_base(dev);
	const uint8_t n_max = 16;
	uint32_t diepmsk;
	uint32_t daint;

	diepmsk = sys_read32((mem_addr_t)&base->diepmsk);
	daint = sys_read32((mem_addr_t)&base->daint);

	for (uint8_t n = 0U; n < n_max; n++) {
		mem_addr_t diepint_reg = (mem_addr_t)&base->in_ep[n].diepint;
		uint32_t diepint;
		uint32_t status;

		if (daint & USB_DWC2_DAINT_INEPINT(n)) {
			/* Read and clear interrupt status */
			diepint = sys_read32(diepint_reg);
			status = diepint & diepmsk;
			sys_write32(status, diepint_reg);

			LOG_DBG("ep 0x%02x interrupt status: 0x%x",
				n | USB_EP_DIR_IN, status);

			if (status & USB_DWC2_DIEPINT_XFERCOMPL) {
				dwc2_handle_xfercompl(dev, n);
			}

		}
	}

	/* Clear IEPINT interrupt */
	sys_write32(USB_DWC2_GINTSTS_IEPINT, (mem_addr_t)&base->gintsts);
}

static inline void dwc2_handle_oepint(const struct device *dev)
{
	struct usb_dwc2_reg *const base = dwc2_get_base(dev);
	const uint8_t n_max = 16;
	uint32_t doepmsk;
	uint32_t daint;

	doepmsk = sys_read32((mem_addr_t)&base->doepmsk);
	daint = sys_read32((mem_addr_t)&base->daint);

	/* No OUT interrupt expected in FIFO mode, just clear interrupt */
	for (uint8_t n = 0U; n < n_max; n++) {
		mem_addr_t doepint_reg = (mem_addr_t)&base->out_ep[n].doepint;
		uint32_t doepint;
		uint32_t status;

		if (daint & USB_DWC2_DAINT_OUTEPINT(n)) {
			/* Read and clear interrupt status */
			doepint = sys_read32(doepint_reg);
			status = doepint & doepmsk;
			sys_write32(status, doepint_reg);

			LOG_DBG("ep 0x%02x interrupt status: 0x%x", n, status);
		}
	}

	/* Clear OEPINT interrupt */
	sys_write32(USB_DWC2_GINTSTS_OEPINT, (mem_addr_t)&base->gintsts);
}

static void udc_dwc2_isr_handler(const struct device *dev)
{
	const struct udc_dwc2_config *const config = dev->config;
	struct usb_dwc2_reg *const base = config->base;
	mem_addr_t gintsts_reg = (mem_addr_t)&base->gintsts;
	uint32_t int_status;
	uint32_t gintmsk;

	gintmsk = sys_read32((mem_addr_t)&base->gintmsk);

	/*  Read and handle interrupt status register */
	while ((int_status = sys_read32(gintsts_reg) & gintmsk)) {

		LOG_DBG("GINTSTS 0x%x", int_status);

		if (int_status & USB_DWC2_GINTSTS_USBRST) {
			/* Clear and handle USB Reset interrupt. */
			sys_write32(USB_DWC2_GINTSTS_USBRST, gintsts_reg);
			dwc2_on_bus_reset(dev);
			LOG_DBG("USB Reset interrupt");
			udc_submit_event(dev, UDC_EVT_RESET, 0);
		}

		if (int_status & USB_DWC2_GINTSTS_ENUMDONE) {
			/* Clear and handle Enumeration Done interrupt. */
			sys_write32(USB_DWC2_GINTSTS_ENUMDONE, gintsts_reg);
			dwc2_handle_enumdone(dev);
		}

		if (int_status & USB_DWC2_GINTSTS_USBSUSP) {
			/* Clear USB Suspend interrupt. */
			sys_write32(USB_DWC2_GINTSTS_USBSUSP, gintsts_reg);
			udc_set_suspended(dev, true);
			udc_submit_event(dev, UDC_EVT_SUSPEND, 0);
		}

		if (int_status & USB_DWC2_GINTSTS_WKUPINT) {
			/* Clear Resume/Remote Wakeup Detected interrupt. */
			sys_write32(USB_DWC2_GINTSTS_WKUPINT, gintsts_reg);
			udc_set_suspended(dev, false);
			udc_submit_event(dev, UDC_EVT_RESUME, 0);
		}

		if (int_status & USB_DWC2_GINTSTS_RXFLVL) {
			/* Handle RxFIFO Non-Empty interrupt */
			dwc2_handle_rxflvl(dev);
		}

		if (int_status & USB_DWC2_GINTSTS_IEPINT) {
			/* Handle IN Endpoints interrupt */
			dwc2_handle_iepint(dev);
		}

		if (int_status & USB_DWC2_GINTSTS_OEPINT) {
			/* Handle OUT Endpoints interrupt */
			dwc2_handle_oepint(dev);
		}
	}

	if (config->quirks != NULL && config->quirks->irq_clear != NULL) {
		config->quirks->irq_clear(dev);
	}
}

static int udc_dwc2_ep_enqueue(const struct device *dev,
			       struct udc_ep_config *const cfg,
			       struct net_buf *const buf)
{
	struct dwc2_drv_event evt = {
		.ep = cfg->addr,
		.type = DWC2_DRV_EVT_XFER,
	};

	LOG_DBG("%p enqueue %x %p", dev, cfg->addr, buf);
	udc_buf_put(cfg, buf);

	if (!cfg->stat.halted) {
		k_msgq_put(&drv_msgq, &evt, K_NO_WAIT);
	}

	return 0;
}

static int udc_dwc2_ep_dequeue(const struct device *dev,
			       struct udc_ep_config *const cfg)
{
	unsigned int lock_key;
	struct net_buf *buf;

	lock_key = irq_lock();

	if (USB_EP_DIR_IS_IN(cfg->addr)) {
		dwc2_flush_tx_fifo(dev, USB_EP_GET_IDX(cfg->addr));
	}

	buf = udc_buf_get_all(dev, cfg->addr);
	if (buf) {
		udc_submit_ep_event(dev, buf, -ECONNABORTED);
	}

	irq_unlock(lock_key);
	LOG_DBG("dequeue ep 0x%02x", cfg->addr);

	return 0;
}

static void dwc2_unset_unused_fifo(const struct device *dev)
{
	struct udc_dwc2_data *const priv = udc_get_private(dev);
	struct udc_ep_config *tmp;

	for (uint8_t i = priv->ineps; i > 0; i--) {
		tmp = udc_get_ep_cfg(dev, i | USB_EP_DIR_IN);

		if (tmp->stat.enabled && (priv->txf_set & BIT(i))) {
			return;
		}

		if (!tmp->stat.enabled && (priv->txf_set & BIT(i))) {
			priv->txf_set &= ~BIT(i);
		}
	}
}

/*
 * In dedicated FIFO mode there are i (i = 1 ... ineps - 1) FIFO size registers,
 * e.g. DIEPTXF1, DIEPTXF2, ... DIEPTXF4. When dynfifosizing is enabled,
 * the size register is mutable. The offset of DIEPTXF1 registers is 0.
 */
static int dwc2_set_dedicated_fifo(const struct device *dev,
				   struct udc_ep_config *const cfg,
				   uint32_t *const diepctl)
{
	struct udc_dwc2_data *const priv = udc_get_private(dev);
	uint8_t ep_idx = USB_EP_GET_IDX(cfg->addr);
	uint32_t txfaddr;
	uint32_t txfdep;
	uint32_t tmp;

	/* Keep everything but FIFO number */
	tmp = *diepctl & ~USB_DWC2_DEPCTL_TXFNUM_MASK;

	if (priv->dynfifosizing) {
		if (priv->txf_set & ~BIT_MASK(ep_idx)) {
			dwc2_unset_unused_fifo(dev);
		}

		if (priv->txf_set & ~BIT_MASK(ep_idx)) {
			LOG_WRN("Some of the FIFOs higher than %u are set, %lx",
				ep_idx, priv->txf_set & ~BIT_MASK(ep_idx));
			return -EIO;
		}

		if ((ep_idx - 1) != 0U) {
			txfaddr = dwc2_get_txfdep(dev, ep_idx - 2) +
				  dwc2_get_txfaddr(dev, ep_idx - 2);
		} else {
			txfaddr = UDC_DWC2_FIFO0_DEPTH + priv->grxfsiz;
		}

		/* Set FIFO depth (32-bit words) and address */
		txfdep = cfg->mps / 4U;
		dwc2_set_txf(dev, ep_idx - 1, txfdep, txfaddr);
	} else {
		txfdep = dwc2_get_txfdep(dev, ep_idx - 1);
		txfaddr = dwc2_get_txfaddr(dev, ep_idx - 1);

		if (cfg->mps < txfdep * 4U) {
			return -ENOMEM;
		}

		LOG_DBG("Reuse FIFO%u addr 0x%08x depth %u", ep_idx, txfaddr, txfdep);
	}

	/* Assign FIFO to the IN endpoint */
	*diepctl = tmp | usb_dwc2_set_depctl_txfnum(ep_idx);
	priv->txf_set |= BIT(ep_idx);
	dwc2_flush_tx_fifo(dev, ep_idx);

	LOG_INF("Set FIFO%u (ep 0x%02x) addr 0x%04x depth %u size %u",
		ep_idx, cfg->addr, txfaddr, txfdep, dwc2_ftx_avail(dev, ep_idx));

	return 0;
}

static int dwc2_ep_control_enable(const struct device *dev,
				  struct udc_ep_config *const cfg)
{
	struct usb_dwc2_reg *const base = dwc2_get_base(dev);
	struct udc_dwc2_data *const priv = udc_get_private(dev);
	mem_addr_t dxepctl0_reg;
	uint32_t dxepctl0;

	dxepctl0_reg = dwc2_get_dxepctl_reg(dev, cfg->addr);
	dxepctl0 = sys_read32(dxepctl0_reg);

	dxepctl0 &= ~USB_DWC2_DEPCTL0_MPS_MASK;
	switch (cfg->mps) {
	case 8:
		dxepctl0 |= USB_DWC2_DEPCTL0_MPS_8 << USB_DWC2_DEPCTL_MPS_POS;
		break;
	case 16:
		dxepctl0 |= USB_DWC2_DEPCTL0_MPS_16 << USB_DWC2_DEPCTL_MPS_POS;
		break;
	case 32:
		dxepctl0 |= USB_DWC2_DEPCTL0_MPS_32 << USB_DWC2_DEPCTL_MPS_POS;
		break;
	case 64:
		dxepctl0 |= USB_DWC2_DEPCTL0_MPS_64 << USB_DWC2_DEPCTL_MPS_POS;
		break;
	default:
		return -EINVAL;
	}

	dxepctl0 |= USB_DWC2_DEPCTL_USBACTEP;

	/*
	 * The following applies to the Control IN endpoint only.
	 *
	 * Set endpoint 0 TxFIFO depth when dynfifosizing is enabled.
	 * Note that only dedicated mode is supported at this time.
	 */
	if (cfg->addr == USB_CONTROL_EP_IN && priv->dynfifosizing) {
		uint32_t gnptxfsiz;

		gnptxfsiz = usb_dwc2_set_gnptxfsiz_nptxfdep(UDC_DWC2_FIFO0_DEPTH) |
			    usb_dwc2_set_gnptxfsiz_nptxfstaddr(priv->grxfsiz);

		sys_write32(gnptxfsiz, (mem_addr_t)&base->gnptxfsiz);
	}

	if (cfg->addr == USB_CONTROL_EP_OUT) {
		int ret;

		dwc2_flush_rx_fifo(dev);
		ret = dwc2_ctrl_feed_dout(dev, 8);
		if (ret) {
			return ret;
		}
	} else {
		dwc2_flush_tx_fifo(dev, 0);
	}

	sys_write32(dxepctl0, dxepctl0_reg);
	dwc2_set_epint(dev, cfg, true);

	return 0;
}

static int udc_dwc2_ep_enable(const struct device *dev,
			      struct udc_ep_config *const cfg)
{
	struct usb_dwc2_reg *const base = dwc2_get_base(dev);
	struct udc_dwc2_data *const priv = udc_get_private(dev);
	uint8_t ep_idx = USB_EP_GET_IDX(cfg->addr);
	mem_addr_t dxepctl_reg;
	uint32_t dxepctl;

	LOG_DBG("Enable ep 0x%02x", cfg->addr);

	if (ep_idx == 0U) {
		return dwc2_ep_control_enable(dev, cfg);
	}

	if (USB_EP_DIR_IS_OUT(cfg->addr)) {
		/* TODO: use dwc2_get_dxepctl_reg() */
		dxepctl_reg = (mem_addr_t)&base->out_ep[ep_idx].doepctl;
	} else {
		if (priv->ineps > 0U && ep_idx > (priv->ineps - 1U)) {
			LOG_ERR("No resources available for ep 0x%02x", cfg->addr);
			return -EINVAL;
		}

		dxepctl_reg = (mem_addr_t)&base->in_ep[ep_idx].diepctl;
	}

	if (cfg->mps > usb_dwc2_get_depctl_mps(UINT16_MAX)) {
		return -EINVAL;
	}

	dxepctl = sys_read32(dxepctl_reg);
	/* Set max packet size */
	dxepctl &= ~USB_DWC2_DEPCTL_MPS_MASK;
	dxepctl |= cfg->mps << USB_DWC2_DEPCTL_MPS_POS;

	/* Set endpoint type */
	dxepctl &= ~USB_DWC2_DEPCTL_EPTYPE_MASK;

	switch (cfg->attributes & USB_EP_TRANSFER_TYPE_MASK) {
	case USB_EP_TYPE_BULK:
		dxepctl |= USB_DWC2_DEPCTL_EPTYPE_BULK <<
			   USB_DWC2_DEPCTL_EPTYPE_POS;
		dxepctl |= USB_DWC2_DEPCTL_SETD0PID;
		break;
	case USB_EP_TYPE_INTERRUPT:
		dxepctl |= USB_DWC2_DEPCTL_EPTYPE_INTERRUPT <<
			   USB_DWC2_DEPCTL_EPTYPE_POS;
		dxepctl |= USB_DWC2_DEPCTL_SETD0PID;
		break;
	case USB_EP_TYPE_ISO:
		dxepctl |= USB_DWC2_DEPCTL_EPTYPE_ISO <<
			   USB_DWC2_DEPCTL_EPTYPE_POS;
		break;
	default:
		return -EINVAL;
	}

	if (USB_EP_DIR_IS_IN(cfg->addr) && cfg->mps != 0U) {
		int ret = dwc2_set_dedicated_fifo(dev, cfg, &dxepctl);

		if (ret) {
			return ret;
		}
	}

	dxepctl |= USB_DWC2_DEPCTL_USBACTEP;

	/* Enable endpoint interrupts */
	dwc2_set_epint(dev, cfg, true);
	sys_write32(dxepctl, dxepctl_reg);

	for (uint8_t i = 1U; i < priv->ineps; i++) {
		LOG_DBG("DIEPTXF%u %08x DIEPCTL%u %08x",
			i, sys_read32((mem_addr_t)base->dieptxf[i - 1U]), i, dxepctl);
	}

	return 0;
}

static int dwc2_unset_dedicated_fifo(const struct device *dev,
				     struct udc_ep_config *const cfg,
				     uint32_t *const diepctl)
{
	struct udc_dwc2_data *const priv = udc_get_private(dev);
	uint8_t ep_idx = USB_EP_GET_IDX(cfg->addr);

	/* Clear FIFO number field */
	*diepctl &= ~USB_DWC2_DEPCTL_TXFNUM_MASK;

	if (priv->dynfifosizing) {
		if (priv->txf_set & ~BIT_MASK(ep_idx)) {
			LOG_WRN("Some of the FIFOs higher than %u are set, %lx",
				ep_idx, priv->txf_set & ~BIT_MASK(ep_idx));
			return 0;
		}

		dwc2_set_txf(dev, ep_idx - 1, 0, 0);
	}

	priv->txf_set &= ~BIT(ep_idx);

	return 0;
}

static int udc_dwc2_ep_disable(const struct device *dev,
			       struct udc_ep_config *const cfg)
{
	uint8_t ep_idx = USB_EP_GET_IDX(cfg->addr);
	mem_addr_t dxepctl_reg;
	uint32_t dxepctl;

	dxepctl_reg = dwc2_get_dxepctl_reg(dev, cfg->addr);
	dxepctl = sys_read32(dxepctl_reg);

	if (dxepctl & USB_DWC2_DEPCTL_USBACTEP) {
		LOG_DBG("Disable ep 0x%02x DxEPCTL%u %x",
			cfg->addr, ep_idx, dxepctl);
		dxepctl |= USB_DWC2_DEPCTL_EPDIS | USB_DWC2_DEPCTL_SNAK;
	} else {
		LOG_WRN("ep 0x%02x is not active DxEPCTL%u %x",
			cfg->addr, ep_idx, dxepctl);
	}

	if (USB_EP_DIR_IS_IN(cfg->addr) && cfg->mps != 0U && ep_idx != 0U) {
		dwc2_unset_dedicated_fifo(dev, cfg, &dxepctl);
	}

	sys_write32(dxepctl, dxepctl_reg);
	dwc2_set_epint(dev, cfg, false);

	return 0;
}

static int udc_dwc2_ep_set_halt(const struct device *dev,
				struct udc_ep_config *const cfg)
{
	uint8_t ep_idx = USB_EP_GET_IDX(cfg->addr);

	sys_set_bits(dwc2_get_dxepctl_reg(dev, cfg->addr), USB_DWC2_DEPCTL_STALL);

	LOG_DBG("Set halt ep 0x%02x", cfg->addr);
	if (ep_idx != 0) {
		cfg->stat.halted = true;
	}

	return 0;
}

static int udc_dwc2_ep_clear_halt(const struct device *dev,
				  struct udc_ep_config *const cfg)
{
	sys_clear_bits(dwc2_get_dxepctl_reg(dev, cfg->addr), USB_DWC2_DEPCTL_STALL);

	LOG_DBG("Clear halt ep 0x%02x", cfg->addr);
	cfg->stat.halted = false;

	return 0;
}

static int udc_dwc2_set_address(const struct device *dev, const uint8_t addr)
{
	struct usb_dwc2_reg *const base = dwc2_get_base(dev);
	mem_addr_t dcfg_reg = (mem_addr_t)&base->dcfg;

	if (addr > (USB_DWC2_DCFG_DEVADDR_MASK >> USB_DWC2_DCFG_DEVADDR_POS)) {
		return -EINVAL;
	}

	sys_clear_bits(dcfg_reg, USB_DWC2_DCFG_DEVADDR_MASK);
	sys_set_bits(dcfg_reg, usb_dwc2_set_dcfg_devaddr(addr));
	LOG_DBG("Set new address %u for %p", addr, dev);

	return 0;
}

static int udc_dwc2_test_mode(const struct device *dev,
			      const uint8_t mode, const bool dryrun)
{
	struct usb_dwc2_reg *const base = dwc2_get_base(dev);
	mem_addr_t dctl_reg = (mem_addr_t)&base->dctl;
	uint32_t tstctl;

	if (mode == 0U || mode > USB_DWC2_DCTL_TSTCTL_TESTFE) {
		return -EINVAL;
	}

	tstctl = usb_dwc2_get_dctl_tstctl(sys_read32(dctl_reg));
	if (tstctl != USB_DWC2_DCTL_TSTCTL_DISABLED) {
		return -EALREADY;
	}

	if (dryrun) {
		LOG_DBG("Test Mode %u supported", mode);
		return 0;
	}

	sys_set_bits(dctl_reg, usb_dwc2_set_dctl_tstctl(mode));
	LOG_DBG("Enable Test Mode %u", mode);

	return 0;
}

static int udc_dwc2_host_wakeup(const struct device *dev)
{
	LOG_DBG("Remote wakeup from %p", dev);

	return -ENOTSUP;
}

/* Return actual USB device speed */
static enum udc_bus_speed udc_dwc2_device_speed(const struct device *dev)
{
	struct udc_dwc2_data *const priv = udc_get_private(dev);

	switch (priv->enumspd) {
	case USB_DWC2_DSTS_ENUMSPD_HS3060:
		return UDC_BUS_SPEED_HS;
	case USB_DWC2_DSTS_ENUMSPD_LS6:
		__ASSERT(false, "Low speed mode not supported");
		__fallthrough;
	case USB_DWC2_DSTS_ENUMSPD_FS48:
		__fallthrough;
	case USB_DWC2_DSTS_ENUMSPD_FS3060:
		__fallthrough;
	default:
		return UDC_BUS_SPEED_FS;
	}
}

static int udc_dwc2_enable(const struct device *dev)
{
	struct usb_dwc2_reg *const base = dwc2_get_base(dev);
	mem_addr_t dctl_reg = (mem_addr_t)&base->dctl;

	/* Disable soft disconnect */
	sys_clear_bits(dctl_reg, USB_DWC2_DCTL_SFTDISCON);
	LOG_DBG("Enable device %p", base);

	return 0;
}

static int udc_dwc2_disable(const struct device *dev)
{
	struct usb_dwc2_reg *const base = dwc2_get_base(dev);
	mem_addr_t dctl_reg = (mem_addr_t)&base->dctl;

	/* Enable soft disconnect */
	sys_set_bits(dctl_reg, USB_DWC2_DCTL_SFTDISCON);
	LOG_DBG("Disable device %p", dev);

	return 0;
}

static int dwc2_core_soft_reset(const struct device *dev)
{
	struct usb_dwc2_reg *const base = dwc2_get_base(dev);
	mem_addr_t grstctl_reg = (mem_addr_t)&base->grstctl;
	const unsigned int csr_timeout_us = 10000UL;
	uint32_t cnt = 0UL;

	/* Check AHB master idle state */
	while (!(sys_read32(grstctl_reg) & USB_DWC2_GRSTCTL_AHBIDLE)) {
		k_busy_wait(1);

		if (++cnt > csr_timeout_us) {
			LOG_ERR("Wait for AHB idle timeout, GRSTCTL 0x%08x",
				sys_read32(grstctl_reg));
			return -EIO;
		}
	}

	/* Apply Core Soft Reset */
	sys_write32(USB_DWC2_GRSTCTL_CSFTRST, grstctl_reg);

	cnt = 0UL;
	do {
		if (++cnt > csr_timeout_us) {
			LOG_ERR("Wait for CSR done timeout, GRSTCTL 0x%08x",
				sys_read32(grstctl_reg));
			return -EIO;
		}

		k_busy_wait(1);
	} while (sys_read32(grstctl_reg) & USB_DWC2_GRSTCTL_CSFTRST &&
		 !(sys_read32(grstctl_reg) & USB_DWC2_GRSTCTL_CSFTRSTDONE));

	sys_clear_bits(grstctl_reg, USB_DWC2_GRSTCTL_CSFTRST | USB_DWC2_GRSTCTL_CSFTRSTDONE);

	return 0;
}

static int udc_dwc2_init(const struct device *dev)
{
	const struct udc_dwc2_config *const config = dev->config;
	struct udc_dwc2_data *const priv = udc_get_private(dev);
	struct usb_dwc2_reg *const base = config->base;
	mem_addr_t gusbcfg_reg = (mem_addr_t)&base->gusbcfg;
	mem_addr_t dcfg_reg = (mem_addr_t)&base->dcfg;
	uint32_t gusbcfg;
	uint32_t ghwcfg2;
	uint32_t ghwcfg3;
	uint32_t ghwcfg4;
	int ret;

	if (config->quirks != NULL && config->quirks->clk_enable != NULL) {
		LOG_DBG("Enable vendor clock");
		ret = config->quirks->clk_enable(dev);
		if (ret) {
			return ret;
		}
	}

	ret = dwc2_init_pinctrl(dev);
	if (ret) {
		return ret;
	}

	ret = dwc2_core_soft_reset(dev);
	if (ret) {
		return ret;
	}

	priv->ghwcfg1 = sys_read32((mem_addr_t)&base->ghwcfg1);
	ghwcfg2 = sys_read32((mem_addr_t)&base->ghwcfg2);
	ghwcfg3 = sys_read32((mem_addr_t)&base->ghwcfg3);
	ghwcfg4 = sys_read32((mem_addr_t)&base->ghwcfg4);

	if (!(ghwcfg4 & USB_DWC2_GHWCFG4_DEDFIFOMODE)) {
		LOG_ERR("Only dedicated TX FIFO mode is supported");
		return -ENOTSUP;
	}

	/*
	 * Force device mode as we do no support role changes.
	 * Wait 25ms for the change to take effect.
	 */
	gusbcfg = USB_DWC2_GUSBCFG_FORCEDEVMODE;
	sys_write32(gusbcfg, gusbcfg_reg);
	k_msleep(25);

	if (ghwcfg2 & USB_DWC2_GHWCFG2_DYNFIFOSIZING) {
		LOG_DBG("Dynamic FIFO Sizing is enabled");
		priv->dynfifosizing = true;
	}

	/* Get the number or endpoints and IN endpoints we can use later */
	priv->numdeveps = usb_dwc2_get_ghwcfg2_numdeveps(ghwcfg2);
	priv->ineps = usb_dwc2_get_ghwcfg4_ineps(ghwcfg4);
	LOG_DBG("Number of endpoints (NUMDEVEPS) %u", priv->numdeveps);
	LOG_DBG("Number of IN endpoints (INEPS) %u", priv->ineps);

	LOG_DBG("Number of periodic IN endpoints (NUMDEVPERIOEPS) %u",
		usb_dwc2_get_ghwcfg4_numdevperioeps(ghwcfg4));
	LOG_DBG("Number of additional control endpoints (NUMCTLEPS) %u",
		usb_dwc2_get_ghwcfg4_numctleps(ghwcfg4));

	LOG_DBG("OTG architecture (OTGARCH) %u, mode (OTGMODE) %u",
		usb_dwc2_get_ghwcfg2_otgarch(ghwcfg2),
		usb_dwc2_get_ghwcfg2_otgmode(ghwcfg2));

	priv->dfifodepth = usb_dwc2_get_ghwcfg3_dfifodepth(ghwcfg3);
	LOG_DBG("DFIFO depth (DFIFODEPTH) %u bytes", priv->dfifodepth * 4);

	priv->max_pktcnt = GHWCFG3_PKTCOUNT(usb_dwc2_get_ghwcfg3_pktsizewidth(ghwcfg3));
	priv->max_xfersize = GHWCFG3_XFERSIZE(usb_dwc2_get_ghwcfg3_xfersizewidth(ghwcfg3));
	LOG_DBG("Max packet count %u, Max transfer size %u",
		priv->max_pktcnt, priv->max_xfersize);

	LOG_DBG("Vendor Control interface support enabled: %s",
		(ghwcfg3 & USB_DWC2_GHWCFG3_VNDCTLSUPT) ? "true" : "false");

	LOG_DBG("PHY interface type: FSPHYTYPE %u, HSPHYTYPE %u, DATAWIDTH %u",
		usb_dwc2_get_ghwcfg2_fsphytype(ghwcfg2),
		usb_dwc2_get_ghwcfg2_hsphytype(ghwcfg2),
		usb_dwc2_get_ghwcfg4_phydatawidth(ghwcfg4));

	LOG_DBG("LPM mode is %s",
		(ghwcfg3 & USB_DWC2_GHWCFG3_LPMMODE) ? "enabled" : "disabled");

	/* Configure PHY and device speed */
	switch (usb_dwc2_get_ghwcfg2_hsphytype(ghwcfg2)) {
	case USB_DWC2_GHWCFG2_HSPHYTYPE_UTMIPLUSULPI:
		__fallthrough;
	case USB_DWC2_GHWCFG2_HSPHYTYPE_ULPI:
		gusbcfg |= USB_DWC2_GUSBCFG_PHYSEL_USB20 |
			   USB_DWC2_GUSBCFG_ULPI_UTMI_SEL_ULPI;
		sys_set_bits(dcfg_reg, USB_DWC2_DCFG_DEVSPD_USBHS20);
		break;
	case USB_DWC2_GHWCFG2_HSPHYTYPE_UTMIPLUS:
		gusbcfg |= USB_DWC2_GUSBCFG_PHYSEL_USB20 |
			   USB_DWC2_GUSBCFG_ULPI_UTMI_SEL_UTMI;
		sys_set_bits(dcfg_reg, USB_DWC2_DCFG_DEVSPD_USBHS20);
		break;
	case USB_DWC2_GHWCFG2_HSPHYTYPE_NO_HS:
		__fallthrough;
	default:
		if (usb_dwc2_get_ghwcfg2_fsphytype(ghwcfg2) !=
		    USB_DWC2_GHWCFG2_FSPHYTYPE_NO_FS) {
			gusbcfg |= USB_DWC2_GUSBCFG_PHYSEL_USB11;
		}

		sys_set_bits(dcfg_reg, USB_DWC2_DCFG_DEVSPD_USBFS1148);
	}

	if (usb_dwc2_get_ghwcfg4_phydatawidth(ghwcfg4)) {
		gusbcfg |= USB_DWC2_GUSBCFG_PHYIF_16_BIT;
	}

	/* Update PHY configuration */
	sys_set_bits(gusbcfg_reg, gusbcfg);

	priv->outeps = 0U;
	for (uint8_t i = 0U; i < priv->numdeveps; i++) {
		uint32_t epdir = usb_dwc2_get_ghwcfg1_epdir(priv->ghwcfg1, i);

		if (epdir == USB_DWC2_GHWCFG1_EPDIR_OUT ||
		    epdir == USB_DWC2_GHWCFG1_EPDIR_BDIR) {
			mem_addr_t doepctl_reg = dwc2_get_dxepctl_reg(dev, i);

			sys_write32(USB_DWC2_DEPCTL_SNAK, doepctl_reg);
			priv->outeps++;
		}
	}

	LOG_DBG("Number of OUT endpoints %u", priv->outeps);

	if (priv->dynfifosizing) {
		priv->grxfsiz = UDC_DWC2_GRXFSIZ_DEFAULT + priv->outeps * 2U;
		sys_write32(usb_dwc2_set_grxfsiz(priv->grxfsiz), (mem_addr_t)&base->grxfsiz);
	}

	LOG_DBG("RX FIFO size %u bytes", priv->grxfsiz * 4);
	for (uint8_t i = 1U; i < priv->ineps; i++) {
		LOG_DBG("TX FIFO%u depth %u addr %u",
			i, dwc2_get_txfdep(dev, i), dwc2_get_txfaddr(dev, i));
	}

	if (udc_ep_enable_internal(dev, USB_CONTROL_EP_OUT,
				   USB_EP_TYPE_CONTROL, 64, 0)) {
		LOG_ERR("Failed to enable control endpoint");
		return -EIO;
	}

	if (udc_ep_enable_internal(dev, USB_CONTROL_EP_IN,
				   USB_EP_TYPE_CONTROL, 64, 0)) {
		LOG_ERR("Failed to enable control endpoint");
		return -EIO;
	}

	/* Unmask interrupts */
	sys_write32(USB_DWC2_GINTSTS_OEPINT | USB_DWC2_GINTSTS_IEPINT |
		    USB_DWC2_GINTSTS_ENUMDONE | USB_DWC2_GINTSTS_USBRST |
		    USB_DWC2_GINTSTS_WKUPINT | USB_DWC2_GINTSTS_USBSUSP,
		    (mem_addr_t)&base->gintmsk);


	/* Call vendor-specific function to enable peripheral */
	if (config->quirks != NULL && config->quirks->pwr_on != NULL) {
		LOG_DBG("Enable vendor power");
		ret = config->quirks->pwr_on(dev);
		if (ret) {
			return ret;
		}
	}

	/* Enable global interrupt */
	sys_set_bits((mem_addr_t)&base->gahbcfg, USB_DWC2_GAHBCFG_GLBINTRMASK);
	config->irq_enable_func(dev);

	return 0;
}

static int udc_dwc2_shutdown(const struct device *dev)
{
	const struct udc_dwc2_config *const config = dev->config;
	struct usb_dwc2_reg *const base = config->base;

	config->irq_disable_func(dev);
	sys_clear_bits((mem_addr_t)&base->gahbcfg, USB_DWC2_GAHBCFG_GLBINTRMASK);

	if (udc_ep_disable_internal(dev, USB_CONTROL_EP_OUT)) {
		LOG_DBG("Failed to disable control endpoint");
		return -EIO;
	}

	if (udc_ep_disable_internal(dev, USB_CONTROL_EP_IN)) {
		LOG_DBG("Failed to disable control endpoint");
		return -EIO;
	}

	return 0;
}

static int dwc2_driver_preinit(const struct device *dev)
{
	const struct udc_dwc2_config *config = dev->config;
	struct udc_data *data = dev->data;
	uint16_t mps = 1023;
	int err;

	k_mutex_init(&data->mutex);

	data->caps.rwup = true;
	data->caps.addr_before_status = true;
	data->caps.mps0 = UDC_MPS0_64;
	if (config->speed_idx == 2) {
		data->caps.hs = true;
		mps = 1024;
	}

	for (int i = 0; i < config->num_of_eps; i++) {
		config->ep_cfg_out[i].caps.out = 1;
		if (i == 0) {
			config->ep_cfg_out[i].caps.control = 1;
			config->ep_cfg_out[i].caps.mps = 64;
		} else {
			config->ep_cfg_out[i].caps.bulk = 1;
			config->ep_cfg_out[i].caps.interrupt = 1;
			config->ep_cfg_out[i].caps.iso = 1;
			config->ep_cfg_out[i].caps.mps = mps;
		}

		config->ep_cfg_out[i].addr = USB_EP_DIR_OUT | i;
		err = udc_register_ep(dev, &config->ep_cfg_out[i]);
		if (err != 0) {
			LOG_ERR("Failed to register endpoint");
			return err;
		}
	}

	for (int i = 0; i < config->num_of_eps; i++) {
		config->ep_cfg_in[i].caps.in = 1;
		if (i == 0) {
			config->ep_cfg_in[i].caps.control = 1;
			config->ep_cfg_in[i].caps.mps = 64;
		} else {
			config->ep_cfg_in[i].caps.bulk = 1;
			config->ep_cfg_in[i].caps.interrupt = 1;
			config->ep_cfg_in[i].caps.iso = 1;
			config->ep_cfg_in[i].caps.mps = mps;
		}

		config->ep_cfg_in[i].addr = USB_EP_DIR_IN | i;
		err = udc_register_ep(dev, &config->ep_cfg_in[i]);
		if (err != 0) {
			LOG_ERR("Failed to register endpoint");
			return err;
		}
	}

	config->make_thread(dev);

	return 0;
}

static int udc_dwc2_lock(const struct device *dev)
{
	return udc_lock_internal(dev, K_FOREVER);
}

static int udc_dwc2_unlock(const struct device *dev)
{
	return udc_unlock_internal(dev);
}

static const struct udc_api udc_dwc2_api = {
	.lock = udc_dwc2_lock,
	.unlock = udc_dwc2_unlock,
	.device_speed = udc_dwc2_device_speed,
	.init = udc_dwc2_init,
	.enable = udc_dwc2_enable,
	.disable = udc_dwc2_disable,
	.shutdown = udc_dwc2_shutdown,
	.set_address = udc_dwc2_set_address,
	.test_mode = udc_dwc2_test_mode,
	.host_wakeup = udc_dwc2_host_wakeup,
	.ep_enable = udc_dwc2_ep_enable,
	.ep_disable = udc_dwc2_ep_disable,
	.ep_set_halt = udc_dwc2_ep_set_halt,
	.ep_clear_halt = udc_dwc2_ep_clear_halt,
	.ep_enqueue = udc_dwc2_ep_enqueue,
	.ep_dequeue = udc_dwc2_ep_dequeue,
};

#define DT_DRV_COMPAT snps_dwc2

#define UDC_DWC2_VENDOR_QUIRK_GET(n)						\
	COND_CODE_1(DT_NODE_VENDOR_HAS_IDX(DT_DRV_INST(n), 1),			\
		    (&dwc2_vendor_quirks_##n),					\
		    (NULL))

#define UDC_DWC2_DT_INST_REG_ADDR(n)						\
	COND_CODE_1(DT_NUM_REGS(DT_DRV_INST(n)), (DT_INST_REG_ADDR(n)),		\
		    (DT_INST_REG_ADDR_BY_NAME(n, core)))

#define UDC_DWC2_PINCTRL_DT_INST_DEFINE(n)					\
	COND_CODE_1(DT_INST_PINCTRL_HAS_NAME(n, default),			\
		    (PINCTRL_DT_INST_DEFINE(n)), ())

#define UDC_DWC2_PINCTRL_DT_INST_DEV_CONFIG_GET(n)				\
	COND_CODE_1(DT_INST_PINCTRL_HAS_NAME(n, default),			\
		    ((void *)PINCTRL_DT_INST_DEV_CONFIG_GET(n)), (NULL))

#define UDC_DWC2_IRQ_FLAGS_TYPE0(n)	0
#define UDC_DWC2_IRQ_FLAGS_TYPE1(n)	DT_INST_IRQ(n, type)
#define DW_IRQ_FLAGS(n) \
	_CONCAT(UDC_DWC2_IRQ_FLAGS_TYPE, DT_INST_IRQ_HAS_CELL(n, type))(n)

/*
 * A UDC driver should always be implemented as a multi-instance
 * driver, even if your platform does not require it.
 */
#define UDC_DWC2_DEVICE_DEFINE(n)						\
	UDC_DWC2_PINCTRL_DT_INST_DEFINE(n);					\
										\
	K_THREAD_STACK_DEFINE(udc_dwc2_stack_##n, CONFIG_UDC_DWC2_STACK_SIZE);	\
										\
	static void udc_dwc2_thread_##n(void *dev, void *arg1, void *arg2)	\
	{									\
		while (true) {							\
			dwc2_thread_handler(dev);				\
		}								\
	}									\
										\
	static void udc_dwc2_make_thread_##n(const struct device *dev)		\
	{									\
		struct udc_dwc2_data *priv = udc_get_private(dev);		\
										\
		k_thread_create(&priv->thread_data,				\
				udc_dwc2_stack_##n,				\
				K_THREAD_STACK_SIZEOF(udc_dwc2_stack_##n),	\
				udc_dwc2_thread_##n,				\
				(void *)dev, NULL, NULL,			\
				K_PRIO_COOP(CONFIG_UDC_DWC2_THREAD_PRIORITY),	\
				K_ESSENTIAL,					\
				K_NO_WAIT);					\
		k_thread_name_set(&priv->thread_data, dev->name);		\
	}									\
										\
	static void udc_dwc2_irq_enable_func_##n(const struct device *dev)	\
	{									\
		IRQ_CONNECT(DT_INST_IRQN(n),					\
			    DT_INST_IRQ(n, priority),				\
			    udc_dwc2_isr_handler,				\
			    DEVICE_DT_INST_GET(n),				\
			    DW_IRQ_FLAGS(n));					\
										\
		irq_enable(DT_INST_IRQN(n));					\
	}									\
										\
	static void udc_dwc2_irq_disable_func_##n(const struct device *dev)	\
	{									\
		irq_disable(DT_INST_IRQN(n));					\
	}									\
										\
	static struct udc_ep_config ep_cfg_out[UDC_DWC2_DRV_EP_NUM];		\
	static struct udc_ep_config ep_cfg_in[UDC_DWC2_DRV_EP_NUM];		\
										\
	static const struct udc_dwc2_config udc_dwc2_config_##n = {		\
		.num_of_eps = UDC_DWC2_DRV_EP_NUM,				\
		.ep_cfg_in = ep_cfg_out,					\
		.ep_cfg_out = ep_cfg_in,					\
		.make_thread = udc_dwc2_make_thread_##n,			\
		.base = (struct usb_dwc2_reg *)UDC_DWC2_DT_INST_REG_ADDR(n),	\
		.pcfg = UDC_DWC2_PINCTRL_DT_INST_DEV_CONFIG_GET(n),		\
		.irq_enable_func = udc_dwc2_irq_enable_func_##n,		\
		.irq_disable_func = udc_dwc2_irq_disable_func_##n,		\
		.quirks = UDC_DWC2_VENDOR_QUIRK_GET(n),				\
	};									\
										\
	static struct udc_dwc2_data udc_priv_##n = {				\
	};									\
										\
	static struct udc_data udc_data_##n = {					\
		.mutex = Z_MUTEX_INITIALIZER(udc_data_##n.mutex),		\
		.priv = &udc_priv_##n,						\
	};									\
										\
	DEVICE_DT_INST_DEFINE(n, dwc2_driver_preinit, NULL,			\
			      &udc_data_##n, &udc_dwc2_config_##n,		\
			      POST_KERNEL, CONFIG_KERNEL_INIT_PRIORITY_DEVICE,	\
			      &udc_dwc2_api);

DT_INST_FOREACH_STATUS_OKAY(UDC_DWC2_DEVICE_DEFINE)