/*
 * Copyright Google LLC.
 * Copyright Nordic Semiconductor ASA
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#include "udc_common.h"

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

#include <soc.h>
#include <zephyr/irq.h>
#include <zephyr/kernel.h>
#include <zephyr/drivers/pinctrl.h>
#include <zephyr/drivers/usb/udc.h>

#include <zephyr/logging/log.h>
LOG_MODULE_REGISTER(udc_sam0, CONFIG_UDC_DRIVER_LOG_LEVEL);

/*
 * Although the manual refers to this as an "Endpoint Descriptor structure", it
 * is actually an endpoint buffer descriptor and has a similar function to the
 * buffer descriptor in the UDC Kinetis driver. Do not use the ASF definition
 * as it is incorrect, cumbersome and has a very misleading name.
 */
struct sam0_ebd_bank0 {
	uint32_t addr;
	/* PCKSIZE offset 0x04 */
	unsigned int byte_count : 14;
	unsigned int multi_packet_size : 14;
	unsigned int size : 3;
	unsigned int auto_zlp : 1;
	/* EXTREG offset 0x08*/
	unsigned int subpid : 4;
	unsigned int variable : 11;
	unsigned int reserved0 : 1;
	/* STATUS_BK offset 0x0A*/
	unsigned int erroflow : 1;
	unsigned int crcerr : 1;
	unsigned int reserved1 : 6;
	/* RESERVED */
	uint8_t reserved2[5];
} __packed;

struct sam0_ebd_bank1 {
	uint32_t addr;
	/* PCKSIZE offset 0x14 */
	unsigned int byte_count : 14;
	unsigned int multi_packet_size : 14;
	unsigned int size : 3;
	unsigned int auto_zlp : 1;
	/* RESERVED, no EXTREG */
	uint8_t reserved0[2];
	/* STATUS_BK offset 0x1A*/
	unsigned int erroflow : 1;
	unsigned int crcerr : 1;
	unsigned int reserved1 : 6;
	/* RESERVED */
	uint8_t reserved2[5];
} __packed;

struct sam0_ep_buffer_desc {
	/* Used for OUT endpoints 0x00, 0x01 ... 0x08 */
	struct sam0_ebd_bank0 bank0;
	/* Used for IN endpoints 0x80, 0x81 ... 0x88 */
	struct sam0_ebd_bank1 bank1;
} __packed;

BUILD_ASSERT(sizeof(struct sam0_ep_buffer_desc) == 32, "Broken endpoint buffer descriptor");

struct udc_sam0_config {
	UsbDevice *base;
	struct sam0_ep_buffer_desc *bdt;
	size_t num_of_eps;
	struct udc_ep_config *ep_cfg_in;
	struct udc_ep_config *ep_cfg_out;
	struct pinctrl_dev_config *const pcfg;
	void (*irq_enable_func)(const struct device *dev);
	void (*irq_disable_func)(const struct device *dev);
	void (*make_thread)(const struct device *dev);
};

enum sam0_event_type {
	/* Setup packet received */
	SAM0_EVT_SETUP,
	/* Trigger new transfer (except control OUT) */
	SAM0_EVT_XFER_NEW,
	/* Transfer for specific endpoint is finished */
	SAM0_EVT_XFER_FINISHED,
};

struct udc_sam0_data {
	struct k_thread thread_data;
	/*
	 * events are events that the driver thread waits.
	 * xfer_new and xfer_finished contain information on which endpoints
	 * events SAM0_EVT_XFER_NEW or SAM0_EVT_XFER_FINISHED are triggered.
	 * The mapping is bits 31..16 for IN endpoints and bits 15..0 for OUT
	 * endpoints.
	 */
	struct k_event events;
	atomic_t xfer_new;
	atomic_t xfer_finished;
	/*
	 * This control OUT endpoint buffer is persistent because we have no
	 * control over when the host sends a setup packet. All other endpoints
	 * use multi-packet transfers and transfer buffers directly.
	 */
	uint8_t ctrl_out_buf[64];
	uint8_t setup[8];
};

static inline int udc_ep_to_bnum(const uint8_t ep)
{
	if (USB_EP_DIR_IS_IN(ep)) {
		return 16UL + USB_EP_GET_IDX(ep);
	}

	return USB_EP_GET_IDX(ep);
}

static inline uint8_t udc_pull_ep_from_bmsk(uint32_t *const bitmap)
{
	unsigned int bit;

	__ASSERT_NO_MSG(bitmap && *bitmap);

	bit = find_lsb_set(*bitmap) - 1;
	*bitmap &= ~BIT(bit);

	if (bit >= 16U) {
		return USB_EP_DIR_IN | (bit - 16U);
	} else {
		return USB_EP_DIR_OUT | bit;
	}
}

/* For CTRLA.ENABLE and CTRLA.SWRST */
static void sam0_wait_syncbusy(const struct device *dev)
{
	const struct udc_sam0_config *config = dev->config;
	UsbDevice *const base = config->base;

	while (base->SYNCBUSY.reg != 0) {
	}
}

static void sam0_load_padcal(const struct device *dev)
{
	const struct udc_sam0_config *config = dev->config;
	UsbDevice *const base = config->base;
	uint32_t pad_transn;
	uint32_t pad_transp;
	uint32_t pad_trim;

#ifdef USB_FUSES_TRANSN_ADDR
	pad_transn = *(uint32_t *)USB_FUSES_TRANSN_ADDR;
#else
#define NVM_USB_PAD_TRANSN_POS 45
#define NVM_USB_PAD_TRANSN_SIZE 5
	pad_transn = (*((uint32_t *)(NVMCTRL_OTP4) +
			(NVM_USB_PAD_TRANSN_POS / 32)) >>
		      (NVM_USB_PAD_TRANSN_POS % 32)) &
		     ((1 << NVM_USB_PAD_TRANSN_SIZE) - 1);

	if (pad_transn == 0x1F) {
		pad_transn = 5U;
	}
#endif

	base->PADCAL.bit.TRANSN = pad_transn;

#ifdef USB_FUSES_TRANSP_ADDR
#define NVM_USB_PAD_TRANSP_POS 50
#define NVM_USB_PAD_TRANSP_SIZE 5
	pad_transp = *(uint32_t *)USB_FUSES_TRANSP_ADDR;
#else
	pad_transp = (*((uint32_t *)(NVMCTRL_OTP4) +
			(NVM_USB_PAD_TRANSP_POS / 32)) >>
		      (NVM_USB_PAD_TRANSP_POS % 32)) &
		     ((1 << NVM_USB_PAD_TRANSP_SIZE) - 1);

	if (pad_transp == 0x1F) {
		pad_transp = 29U;
	}
#endif

	base->PADCAL.bit.TRANSP = pad_transp;

#ifdef USB_FUSES_TRIM_ADDR
	pad_trim = *(uint32_t *)USB_FUSES_TRIM_ADDR;
#else
#define NVM_USB_PAD_TRIM_POS 55
#define NVM_USB_PAD_TRIM_SIZE 3
	pad_trim = (*((uint32_t *)(NVMCTRL_OTP4) +
		      (NVM_USB_PAD_TRIM_POS / 32)) >>
		    (NVM_USB_PAD_TRIM_POS % 32)) &
		   ((1 << NVM_USB_PAD_TRIM_SIZE) - 1);

	if (pad_trim == 0x7) {
		pad_trim = 3U;
	}
#endif

	base->PADCAL.bit.TRIM = pad_trim;
}

static uint8_t sam0_get_bd_size(const uint16_t mps)
{
	switch (mps) {
	case 8:
		return 0;
	case 16:
		return 1;
	case 32:
		return 2;
	case 64:
		return 3;
	case 128:
		return 4;
	case 256:
		return 5;
	case 512:
		return 6;
	case 1023:
		return 7;
	default:
		__ASSERT(true, "Wrong maximum packet size value");
		return 0;
	}
}

static struct sam0_ep_buffer_desc *sam0_get_ebd(const struct device *dev, const uint8_t ep)
{
	const struct udc_sam0_config *config = dev->config;

	return &config->bdt[USB_EP_GET_IDX(ep)];
}

static UsbDeviceEndpoint *sam0_get_ep_reg(const struct device *dev, const uint8_t ep)
{
	const struct udc_sam0_config *config = dev->config;
	UsbDevice *const base = config->base;

	return &base->DeviceEndpoint[USB_EP_GET_IDX(ep)];
}

static int sam0_prep_out(const struct device *dev,
			 struct net_buf *const buf, struct udc_ep_config *const ep_cfg)
{
	UsbDeviceEndpoint *const endpoint = sam0_get_ep_reg(dev, ep_cfg->addr);
	struct sam0_ep_buffer_desc *const bd = sam0_get_ebd(dev, ep_cfg->addr);
	const uint16_t size = MIN(16383U, net_buf_tailroom(buf));
	unsigned int lock_key;

	if (!endpoint->EPSTATUS.bit.BK0RDY) {
		LOG_ERR("ep 0x%02x buffer is used by the controller", ep_cfg->addr);
		return -EBUSY;
	}

	lock_key = irq_lock();
	if (ep_cfg->addr != USB_CONTROL_EP_OUT) {
		bd->bank0.addr = (uintptr_t)buf->data;
		bd->bank0.byte_count = 0;

		bd->bank0.multi_packet_size = size;
		bd->bank0.size = sam0_get_bd_size(udc_mps_ep_size(ep_cfg));
	}

	endpoint->EPSTATUSCLR.bit.BK0RDY = 1;
	irq_unlock(lock_key);

	LOG_DBG("Prepare OUT ep 0x%02x size %u", ep_cfg->addr, size);

	return 0;
}

static int sam0_prep_in(const struct device *dev,
			struct net_buf *const buf, struct udc_ep_config *const ep_cfg)
{
	UsbDeviceEndpoint *const endpoint = sam0_get_ep_reg(dev, ep_cfg->addr);
	struct sam0_ep_buffer_desc *const bd = sam0_get_ebd(dev, ep_cfg->addr);
	const uint16_t len = MIN(16383U, buf->len);
	unsigned int lock_key;

	if (endpoint->EPSTATUS.bit.BK1RDY) {
		LOG_ERR("ep 0x%02x buffer is used by the controller", ep_cfg->addr);
		return -EAGAIN;
	}

	lock_key = irq_lock();

	bd->bank1.addr = (uintptr_t)buf->data;
	bd->bank1.size = sam0_get_bd_size(udc_mps_ep_size(ep_cfg));

	bd->bank1.multi_packet_size = 0;
	bd->bank1.byte_count = len;
	bd->bank1.auto_zlp = 0;

	endpoint->EPSTATUSSET.bit.BK1RDY = 1;
	irq_unlock(lock_key);

	LOG_DBG("Prepare IN ep 0x%02x length %u", ep_cfg->addr, len);

	return 0;
}

static int sam0_ctrl_feed_dout(const struct device *dev, const size_t length)
{
	struct udc_ep_config *const ep_cfg = udc_get_ep_cfg(dev, USB_CONTROL_EP_OUT);
	struct net_buf *buf;

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

	udc_buf_put(ep_cfg, buf);

	return sam0_prep_out(dev, buf, ep_cfg);
}

static void drop_control_transfers(const struct device *dev)
{
	struct net_buf *buf;

	buf = udc_buf_get_all(udc_get_ep_cfg(dev, USB_CONTROL_EP_OUT));
	if (buf != NULL) {
		net_buf_unref(buf);
	}

	buf = udc_buf_get_all(udc_get_ep_cfg(dev, USB_CONTROL_EP_IN));
	if (buf != NULL) {
		net_buf_unref(buf);
	}
}

static int sam0_handle_evt_setup(const struct device *dev)
{
	struct udc_sam0_data *const priv = udc_get_private(dev);
	struct net_buf *buf;
	int err;

	drop_control_transfers(dev);

	buf = udc_ctrl_alloc(dev, USB_CONTROL_EP_OUT, 8);
	if (buf == NULL) {
		return -ENOMEM;
	}

	net_buf_add_mem(buf, priv->setup, sizeof(priv->setup));
	udc_ep_buf_set_setup(buf);

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

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

		err = sam0_ctrl_feed_dout(dev, udc_data_stage_length(buf));
		if (err == -ENOMEM) {
			udc_submit_ep_event(dev, buf, err);
		} else {
			return err;
		}
	} else if (udc_ctrl_stage_is_data_in(dev)) {
		LOG_DBG("s:%p|feed for -in-status", (void *)buf);
		err = udc_ctrl_submit_s_in_status(dev);
	} else {
		LOG_DBG("s:%p|no data", (void *)buf);
		err = udc_ctrl_submit_s_status(dev);
	}

	return err;
}

static int sam0_handle_evt_din(const struct device *dev,
			       struct udc_ep_config *const ep_cfg)
{
	struct net_buf *buf;

	buf = udc_buf_get(ep_cfg);
	if (buf == NULL) {
		LOG_ERR("No buffer for ep 0x%02x", ep_cfg->addr);
		return -ENOBUFS;
	}

	udc_ep_set_busy(ep_cfg, false);

	if (ep_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)) {
			int err;

			/* IN transfer finished, submit buffer for status stage */
			net_buf_unref(buf);

			err = sam0_ctrl_feed_dout(dev, 0);
			if (err == -ENOMEM) {
				udc_submit_ep_event(dev, buf, err);
			} else {
				return err;
			}
		}

		return 0;
	}

	return udc_submit_ep_event(dev, buf, 0);
}

static inline int sam0_handle_evt_dout(const struct device *dev,
				       struct udc_ep_config *const ep_cfg)
{
	struct net_buf *buf;
	int err = 0;

	buf = udc_buf_get(ep_cfg);
	if (buf == NULL) {
		LOG_ERR("No buffer for OUT ep 0x%02x", ep_cfg->addr);
		return -ENODATA;
	}

	udc_ep_set_busy(ep_cfg, false);

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

			/* 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_in(dev)) {
			err = udc_ctrl_submit_s_out_status(dev, buf);
		}
	} else {
		err = udc_submit_ep_event(dev, buf, 0);
	}

	return err;
}

static void sam0_handle_xfer_next(const struct device *dev,
				  struct udc_ep_config *const ep_cfg)
{
	struct net_buf *buf;
	int err;

	buf = udc_buf_peek(ep_cfg);
	if (buf == NULL) {
		return;
	}

	if (USB_EP_DIR_IS_OUT(ep_cfg->addr)) {
		err = sam0_prep_out(dev, buf, ep_cfg);
	} else {
		err = sam0_prep_in(dev, buf, ep_cfg);
	}

	if (err != 0) {
		buf = udc_buf_get(ep_cfg);
		udc_submit_ep_event(dev, buf, -ECONNREFUSED);
	} else {
		udc_ep_set_busy(ep_cfg, true);
	}
}

static ALWAYS_INLINE void sam0_thread_handler(const struct device *const dev)
{
	struct udc_sam0_data *const priv = udc_get_private(dev);
	struct udc_ep_config *ep_cfg;
	uint32_t evt;
	uint32_t eps;
	uint8_t ep;
	int err;

	evt = k_event_wait(&priv->events, UINT32_MAX, false, K_FOREVER);
	udc_lock_internal(dev, K_FOREVER);

	if (evt & BIT(SAM0_EVT_XFER_FINISHED)) {
		k_event_clear(&priv->events, BIT(SAM0_EVT_XFER_FINISHED));

		eps = atomic_clear(&priv->xfer_finished);

		while (eps) {
			ep = udc_pull_ep_from_bmsk(&eps);
			ep_cfg = udc_get_ep_cfg(dev, ep);
			LOG_DBG("Finished event ep 0x%02x", ep);

			if (USB_EP_DIR_IS_IN(ep)) {
				err = sam0_handle_evt_din(dev, ep_cfg);
			} else {
				err = sam0_handle_evt_dout(dev, ep_cfg);
			}

			if (err) {
				udc_submit_event(dev, UDC_EVT_ERROR, err);
			}

			if (!udc_ep_is_busy(ep_cfg)) {
				sam0_handle_xfer_next(dev, ep_cfg);
			} else {
				LOG_ERR("Endpoint 0x%02x busy", ep);
			}
		}
	}

	if (evt & BIT(SAM0_EVT_XFER_NEW)) {
		k_event_clear(&priv->events, BIT(SAM0_EVT_XFER_NEW));

		eps = atomic_clear(&priv->xfer_new);

		while (eps) {
			ep = udc_pull_ep_from_bmsk(&eps);
			ep_cfg = udc_get_ep_cfg(dev, ep);
			LOG_INF("New transfer ep 0x%02x in the queue", ep);

			if (!udc_ep_is_busy(ep_cfg)) {
				sam0_handle_xfer_next(dev, ep_cfg);
			} else {
				LOG_ERR("Endpoint 0x%02x busy", ep);
			}
		}
	}

	if (evt & BIT(SAM0_EVT_SETUP)) {
		k_event_clear(&priv->events, BIT(SAM0_EVT_SETUP));
		err = sam0_handle_evt_setup(dev);
		if (err) {
			udc_submit_event(dev, UDC_EVT_ERROR, err);
		}
	}

	udc_unlock_internal(dev);
}

static void sam0_handle_setup_isr(const struct device *dev)
{
	struct sam0_ep_buffer_desc *const bd = sam0_get_ebd(dev, 0);
	struct udc_sam0_data *const priv = udc_get_private(dev);

	if (bd->bank0.byte_count != 8) {
		LOG_ERR("Wrong byte count %u for setup packet",
			bd->bank0.byte_count);
	}

	memcpy(priv->setup, priv->ctrl_out_buf, sizeof(priv->setup));
	k_event_post(&priv->events, BIT(SAM0_EVT_SETUP));
}

static void sam0_handle_out_isr(const struct device *dev, const uint8_t ep)
{
	struct sam0_ep_buffer_desc *const bd = sam0_get_ebd(dev, ep);
	UsbDeviceEndpoint *const endpoint = sam0_get_ep_reg(dev, ep);
	struct udc_sam0_data *const priv = udc_get_private(dev);
	struct udc_ep_config *ep_cfg = udc_get_ep_cfg(dev, ep);
	struct net_buf *buf;
	uint32_t size;

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

	LOG_DBG("ISR ep 0x%02x byte_count %u room %u mps %u",
		ep, bd->bank0.byte_count, net_buf_tailroom(buf), udc_mps_ep_size(ep_cfg));

	size = MIN(bd->bank0.byte_count, net_buf_tailroom(buf));
	if (ep == USB_CONTROL_EP_OUT) {
		net_buf_add_mem(buf, priv->ctrl_out_buf, size);
	} else {
		net_buf_add(buf, size);
	}

	/*
	 * The remaining buffer size should actually be at least equal to MPS,
	 * if (net_buf_tailroom(buf) >= udc_mps_ep_size(ep_cfg) && ...,
	 * otherwise the controller may write outside the buffer, this must be
	 * fixed in the UDC buffer allocation.
	 */
	if (net_buf_tailroom(buf) && size == udc_mps_ep_size(ep_cfg)) {
		__maybe_unused int err;

		if (ep == USB_CONTROL_EP_OUT) {
			/* This is the same as sam0_prep_out() would do for the
			 * control OUT endpoint, but shorter.
			 */
			endpoint->EPSTATUSCLR.bit.BK0RDY = 1;
		} else {
			err = sam0_prep_out(dev, buf, ep_cfg);
			__ASSERT(err == 0, "Failed to start new OUT transaction");
		}
	} else {
		atomic_set_bit(&priv->xfer_finished, udc_ep_to_bnum(ep));
		k_event_post(&priv->events, BIT(SAM0_EVT_XFER_FINISHED));
	}
}

static void sam0_handle_in_isr(const struct device *dev, const uint8_t ep)
{
	struct sam0_ep_buffer_desc *const bd = sam0_get_ebd(dev, ep);
	struct udc_sam0_data *const priv = udc_get_private(dev);
	struct udc_ep_config *ep_cfg = udc_get_ep_cfg(dev, ep);
	__maybe_unused int err = 0;
	struct net_buf *buf;
	uint32_t len;

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

	len = bd->bank1.byte_count;
	LOG_DBG("ISR ep 0x%02x byte_count %u", ep, len);
	net_buf_pull(buf, len);

	if (buf->len) {
		err = sam0_prep_in(dev, buf, ep_cfg);
		__ASSERT(err == 0, "Failed to start new IN transaction");
	} else {
		if (udc_ep_buf_has_zlp(buf)) {
			err = sam0_prep_in(dev, buf, ep_cfg);
			__ASSERT(err == 0, "Failed to start new IN transaction");
			udc_ep_buf_clear_zlp(buf);
			return;
		}

		atomic_set_bit(&priv->xfer_finished, udc_ep_to_bnum(ep));
		k_event_post(&priv->events, BIT(SAM0_EVT_XFER_FINISHED));
	}
}

static void ALWAYS_INLINE handle_ep_isr(const struct device *dev, const uint8_t idx)
{
	UsbDeviceEndpoint *const endpoint = sam0_get_ep_reg(dev, idx);
	uint32_t intflag;

	intflag = endpoint->EPINTFLAG.reg;
	/* Clear endpoint interrupt flags */
	endpoint->EPINTFLAG.reg = intflag;

	if (intflag & USB_DEVICE_EPINTFLAG_TRCPT1) {
		sam0_handle_in_isr(dev, idx | USB_EP_DIR_IN);
	}

	if (intflag & USB_DEVICE_EPINTFLAG_TRCPT0) {
		sam0_handle_out_isr(dev, idx);
	}

	if (intflag & USB_DEVICE_EPINTFLAG_RXSTP) {
		sam0_handle_setup_isr(dev);
	}

}

static void sam0_isr_handler(const struct device *dev)
{
	const struct udc_sam0_config *config = dev->config;
	UsbDevice *const base = config->base;
	uint32_t epintsmry = base->EPINTSMRY.reg;
	uint32_t intflag;

	/* Check endpoint interrupts bit-by-bit */
	for (uint8_t idx = 0U; epintsmry != 0U; epintsmry >>= 1) {
		if ((epintsmry & 1) != 0U) {
			handle_ep_isr(dev, idx);
		}

		idx++;
	}

	intflag = base->INTFLAG.reg;
	/* Clear interrupt flags */
	base->INTFLAG.reg = intflag;

	if (intflag & USB_DEVICE_INTFLAG_SOF) {
		udc_submit_sof_event(dev);
	}

	if (intflag & USB_DEVICE_INTFLAG_EORST) {
		UsbDeviceEndpoint *const endpoint = sam0_get_ep_reg(dev, 0);

		/* Re-enable control endpoint interrupts */
		endpoint->EPINTENSET.reg = USB_DEVICE_EPINTENSET_TRCPT0 |
					   USB_DEVICE_EPINTENSET_TRCPT1 |
					   USB_DEVICE_EPINTENSET_RXSTP;

		udc_submit_event(dev, UDC_EVT_RESET, 0);
	}

	if (intflag & USB_DEVICE_INTFLAG_SUSPEND) {
		if (!udc_is_suspended(dev)) {
			udc_set_suspended(dev, true);
			udc_submit_event(dev, UDC_EVT_SUSPEND, 0);
		}
	}

	if (intflag & USB_DEVICE_INTFLAG_EORSM) {
		if (udc_is_suspended(dev)) {
			udc_set_suspended(dev, false);
			udc_submit_event(dev, UDC_EVT_RESUME, 0);
		}
	}

	/*
	 * This controller does not support VBUS status detection. To work
	 * smoothly, we should consider whether it would be possible to use the
	 * GPIO pin for VBUS state detection (e.g. PA7 on SAM R21 Xplained Pro).
	 */

	if (intflag & USB_DEVICE_INTFLAG_RAMACER) {
		udc_submit_event(dev, UDC_EVT_ERROR, -EINVAL);
	}
}

static int udc_sam0_ep_enqueue(const struct device *dev,
			       struct udc_ep_config *const ep_cfg, struct net_buf *buf)
{
	struct udc_sam0_data *const priv = udc_get_private(dev);

	LOG_DBG("%s enqueue 0x%02x %p", dev->name, ep_cfg->addr, (void *)buf);
	udc_buf_put(ep_cfg, buf);

	if (!ep_cfg->stat.halted) {
		atomic_set_bit(&priv->xfer_new, udc_ep_to_bnum(ep_cfg->addr));
		k_event_post(&priv->events, BIT(SAM0_EVT_XFER_NEW));
	}

	return 0;
}

static int udc_sam0_ep_dequeue(const struct device *dev, struct udc_ep_config *const ep_cfg)
{
	UsbDeviceEndpoint *const endpoint = sam0_get_ep_reg(dev, ep_cfg->addr);
	unsigned int lock_key;
	struct net_buf *buf;

	lock_key = irq_lock();

	if (USB_EP_DIR_IS_IN(ep_cfg->addr)) {
		endpoint->EPSTATUSCLR.bit.BK1RDY = 1;
	} else {
		endpoint->EPSTATUSSET.bit.BK0RDY = 1;
	}

	buf = udc_buf_get_all(ep_cfg);
	if (buf) {
		udc_submit_ep_event(dev, buf, -ECONNABORTED);
		udc_ep_set_busy(ep_cfg, false);
	}

	irq_unlock(lock_key);

	return 0;
}

static void setup_control_out_ep(const struct device *dev)
{
	struct sam0_ep_buffer_desc *const bd = sam0_get_ebd(dev, 0);
	struct udc_sam0_data *const priv = udc_get_private(dev);

	/* It will never be reassigned to anything else during device runtime. */
	bd->bank0.addr = (uintptr_t)priv->ctrl_out_buf;
	bd->bank0.multi_packet_size = 0;
	bd->bank0.size = sam0_get_bd_size(64);
	bd->bank0.auto_zlp = 0;
}

static int udc_sam0_ep_enable(const struct device *dev, struct udc_ep_config *const ep_cfg)
{
	UsbDeviceEndpoint *const endpoint = sam0_get_ep_reg(dev, ep_cfg->addr);
	uint8_t type;

	switch (ep_cfg->attributes & USB_EP_TRANSFER_TYPE_MASK) {
	case USB_EP_TYPE_CONTROL:
		type = 1;
		break;
	case USB_EP_TYPE_ISO:
		type = 2;
		break;
	case USB_EP_TYPE_BULK:
		type = 3;
		break;
	case USB_EP_TYPE_INTERRUPT:
		type = 4;
		break;
	default:
		return -EINVAL;
	}

	if (ep_cfg->addr == USB_CONTROL_EP_OUT) {
		setup_control_out_ep(dev);
		endpoint->EPINTENSET.reg = USB_DEVICE_EPINTENSET_RXSTP;
	}

	if (USB_EP_DIR_IS_IN(ep_cfg->addr)) {
		endpoint->EPCFG.bit.EPTYPE1 = type;
		endpoint->EPSTATUSCLR.bit.BK1RDY = 1;
		endpoint->EPINTENSET.reg = USB_DEVICE_EPINTENSET_TRCPT1;
	} else {
		endpoint->EPCFG.bit.EPTYPE0 = type;
		endpoint->EPSTATUSSET.bit.BK0RDY = 1;
		endpoint->EPINTENSET.reg = USB_DEVICE_EPINTENSET_TRCPT0;
	}

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

	return 0;
}

static int udc_sam0_ep_disable(const struct device *dev, struct udc_ep_config *const ep_cfg)
{
	UsbDeviceEndpoint *const endpoint = sam0_get_ep_reg(dev, ep_cfg->addr);

	if (ep_cfg->addr == USB_CONTROL_EP_OUT) {
		endpoint->EPINTENCLR.reg = USB_DEVICE_EPINTENCLR_RXSTP;
	}

	if (USB_EP_DIR_IS_IN(ep_cfg->addr)) {
		endpoint->EPINTENCLR.reg = USB_DEVICE_EPINTENCLR_TRCPT1;
		endpoint->EPCFG.bit.EPTYPE1 = 0;
	} else {
		endpoint->EPINTENCLR.reg = USB_DEVICE_EPINTENCLR_TRCPT0;
		endpoint->EPCFG.bit.EPTYPE0 = 0;
	}

	LOG_DBG("Disable ep 0x%02x", ep_cfg->addr);

	return 0;
}

static int udc_sam0_ep_set_halt(const struct device *dev, struct udc_ep_config *const ep_cfg)
{
	UsbDeviceEndpoint *const endpoint = sam0_get_ep_reg(dev, ep_cfg->addr);

	if (USB_EP_DIR_IS_IN(ep_cfg->addr)) {
		endpoint->EPSTATUSSET.bit.STALLRQ1 = 1;
	} else {
		endpoint->EPSTATUSSET.bit.STALLRQ0 = 1;
	}

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

	return 0;
}

static int udc_sam0_ep_clear_halt(const struct device *dev, struct udc_ep_config *const ep_cfg)
{
	UsbDeviceEndpoint *const endpoint = sam0_get_ep_reg(dev, ep_cfg->addr);
	struct udc_sam0_data *const priv = udc_get_private(dev);

	if (USB_EP_GET_IDX(ep_cfg->addr) == 0) {
		return 0;
	}

	if (USB_EP_DIR_IS_IN(ep_cfg->addr)) {
		endpoint->EPSTATUSCLR.bit.STALLRQ1 = 1;
		endpoint->EPSTATUSCLR.bit.DTGLIN = 1;
	} else {
		endpoint->EPSTATUSCLR.bit.STALLRQ0 = 1;
		endpoint->EPSTATUSCLR.bit.DTGLOUT = 1;
	}

	if (USB_EP_GET_IDX(ep_cfg->addr) != 0 && !udc_ep_is_busy(ep_cfg)) {
		if (udc_buf_peek(ep_cfg)) {
			atomic_set_bit(&priv->xfer_new, udc_ep_to_bnum(ep_cfg->addr));
			k_event_post(&priv->events, BIT(SAM0_EVT_XFER_NEW));
		}
	}

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

	return 0;
}

static int udc_sam0_set_address(const struct device *dev, const uint8_t addr)
{
	const struct udc_sam0_config *config = dev->config;
	UsbDevice *const base = config->base;

	LOG_DBG("Set new address %u for %s", addr, dev->name);
	if (addr != 0) {
		base->DADD.reg = addr | USB_DEVICE_DADD_ADDEN;
	} else {
		base->DADD.reg = 0;
	}

	return 0;
}

static int udc_sam0_host_wakeup(const struct device *dev)
{
	const struct udc_sam0_config *config = dev->config;
	UsbDevice *const base = config->base;

	LOG_DBG("Remote wakeup from %s", dev->name);
	base->CTRLB.bit.UPRSM = 1;

	return 0;
}

static enum udc_bus_speed udc_sam0_device_speed(const struct device *dev)
{
	struct udc_data *data = dev->data;

	return data->caps.hs ? UDC_BUS_SPEED_HS : UDC_BUS_SPEED_FS;
}

static int udc_sam0_enable(const struct device *dev)
{
	const struct udc_sam0_config *config = dev->config;
	const struct pinctrl_dev_config *const pcfg = config->pcfg;
	UsbDevice *const base = config->base;
	int ret;

#ifdef MCLK
	/* Enable the clock in MCLK */
	MCLK->APBBMASK.bit.USB_ = 1;

	/* Enable the GCLK - use 48 MHz source */
	GCLK->PCHCTRL[USB_GCLK_ID].reg = GCLK_PCHCTRL_GEN(2) | GCLK_PCHCTRL_CHEN;

	while (GCLK->SYNCBUSY.reg) {
	}
#else
	/* Enable the clock in PM */
	PM->APBBMASK.bit.USB_ = 1;

	/* Enable the GCLK */
	GCLK->CLKCTRL.reg = GCLK_CLKCTRL_ID_USB | GCLK_CLKCTRL_GEN_GCLK0 |
			    GCLK_CLKCTRL_CLKEN;

	while (GCLK->STATUS.bit.SYNCBUSY) {
	}
#endif

	/* Reset controller */
	base->CTRLA.bit.SWRST = 1;
	sam0_wait_syncbusy(dev);

	/*
	 * Change QOS values to have the best performance and correct USB
	 * behaviour.
	 */
	base->QOSCTRL.bit.CQOS = 2;
	base->QOSCTRL.bit.DQOS = 2;

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

	sam0_load_padcal(dev);

	base->CTRLA.reg = USB_CTRLA_MODE_DEVICE | USB_CTRLA_RUNSTDBY;
	base->CTRLB.reg = USB_DEVICE_CTRLB_SPDCONF_FS;

	base->DESCADD.reg = (uintptr_t)config->bdt;

	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;
	}

	base->INTENSET.reg = USB_DEVICE_INTENSET_EORSM |
			     USB_DEVICE_INTENSET_EORST |
			     USB_DEVICE_INTENSET_SUSPEND;

	base->CTRLA.bit.ENABLE = 1;
	sam0_wait_syncbusy(dev);
	base->CTRLB.bit.DETACH = 0;

	config->irq_enable_func(dev);
	LOG_DBG("Enable device %s", dev->name);

	return 0;
}

static int udc_sam0_disable(const struct device *dev)
{
	const struct udc_sam0_config *config = dev->config;
	UsbDevice *const base = config->base;

	config->irq_disable_func(dev);
	base->CTRLB.bit.DETACH = 1;
	base->CTRLA.bit.ENABLE = 0;
	sam0_wait_syncbusy(dev);

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

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

#ifdef MCLK
	/* Disable 48 MHz clock source in GCLK */
	GCLK->PCHCTRL[USB_GCLK_ID].reg = 0;

	/* Disable the clock in MCLK */
	MCLK->APBBMASK.bit.USB_ = 0;

	while (GCLK->SYNCBUSY.reg) {
	}
#else
	/* Disable clock source in GCLK */
	GCLK->CLKCTRL.reg = 0;

	/* Disable the clock in PM */
	PM->APBBMASK.bit.USB_ = 0;

	while (GCLK->STATUS.bit.SYNCBUSY) {
	}
#endif

	LOG_DBG("Disable device %s", dev->name);

	return 0;
}

/*
 * Nothing to do here as the controller does not support VBUS state change
 * detection and there is nothing to initialize in the controller to do this.
 */
static int udc_sam0_init(const struct device *dev)
{
	LOG_DBG("Init device %s", dev->name);

	return 0;
}

static int udc_sam0_shutdown(const struct device *dev)
{
	LOG_DBG("Shutdown device %s", dev->name);

	return 0;
}

static int udc_sam0_driver_preinit(const struct device *dev)
{
	const struct udc_sam0_config *config = dev->config;
	struct udc_sam0_data *priv = udc_get_private(dev);
	struct udc_data *data = dev->data;
	uint16_t mps = 1023;
	int err;

	k_mutex_init(&data->mutex);
	k_event_init(&priv->events);
	atomic_clear(&priv->xfer_new);
	atomic_clear(&priv->xfer_finished);

	data->caps.rwup = true;
	data->caps.mps0 = UDC_MPS0_64;

	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 void udc_sam0_lock(const struct device *dev)
{
	k_sched_lock();
	udc_lock_internal(dev, K_FOREVER);
}

static void udc_sam0_unlock(const struct device *dev)
{
	udc_unlock_internal(dev);
	k_sched_unlock();
}

static const struct udc_api udc_sam0_api = {
	.lock = udc_sam0_lock,
	.unlock = udc_sam0_unlock,
	.device_speed = udc_sam0_device_speed,
	.init = udc_sam0_init,
	.enable = udc_sam0_enable,
	.disable = udc_sam0_disable,
	.shutdown = udc_sam0_shutdown,
	.set_address = udc_sam0_set_address,
	.host_wakeup = udc_sam0_host_wakeup,
	.ep_enable = udc_sam0_ep_enable,
	.ep_disable = udc_sam0_ep_disable,
	.ep_set_halt = udc_sam0_ep_set_halt,
	.ep_clear_halt = udc_sam0_ep_clear_halt,
	.ep_enqueue = udc_sam0_ep_enqueue,
	.ep_dequeue = udc_sam0_ep_dequeue,
};

#define DT_DRV_COMPAT atmel_sam0_usb

#define UDC_SAM0_IRQ_ENABLE(i, n)						\
	IRQ_CONNECT(DT_INST_IRQ_BY_IDX(n, i, irq),				\
		    DT_INST_IRQ_BY_IDX(n, i, priority),				\
		    sam0_isr_handler, DEVICE_DT_INST_GET(n), 0);		\
	irq_enable(DT_INST_IRQ_BY_IDX(n, i, irq));

#define UDC_SAM0_IRQ_DISABLE(i, n)						\
	irq_disable(DT_INST_IRQ_BY_IDX(n, i, irq));

#define UDC_SAM0_IRQ_ENABLE_DEFINE(i, n)					\
static void udc_sam0_irq_enable_func_##n(const struct device *dev)		\
{										\
	LISTIFY(DT_INST_NUM_IRQS(n), UDC_SAM0_IRQ_ENABLE, (), n)		\
}

#define UDC_SAM0_IRQ_DISABLE_DEFINE(i, n)					\
static void udc_sam0_irq_disable_func_##n(const struct device *dev)		\
{										\
	LISTIFY(DT_INST_NUM_IRQS(n), UDC_SAM0_IRQ_DISABLE, (), n)		\
}

#define UDC_SAM0_PINCTRL_DT_INST_DEFINE(n)					\
	COND_CODE_1(DT_INST_PINCTRL_HAS_NAME(n, default),			\
		    (PINCTRL_DT_INST_DEFINE(n)), ())

#define UDC_SAM0_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_SAM0_DEVICE_DEFINE(n)						\
	UDC_SAM0_PINCTRL_DT_INST_DEFINE(n);					\
	UDC_SAM0_IRQ_ENABLE_DEFINE(i, n);					\
	UDC_SAM0_IRQ_DISABLE_DEFINE(i, n);					\
										\
	K_THREAD_STACK_DEFINE(udc_sam0_stack_##n, CONFIG_UDC_SAM0_STACK_SIZE);	\
										\
	static __aligned(sizeof(void *)) struct sam0_ep_buffer_desc		\
		sam0_bdt_##n[DT_INST_PROP(n, num_bidir_endpoints)];		\
										\
	static void udc_sam0_thread_##n(void *dev, void *arg1, void *arg2)	\
	{									\
		while (true) {							\
			sam0_thread_handler(dev);				\
		}								\
	}									\
										\
	static void udc_sam0_make_thread_##n(const struct device *dev)		\
	{									\
		struct udc_sam0_data *priv = udc_get_private(dev);		\
										\
		k_thread_create(&priv->thread_data,				\
				udc_sam0_stack_##n,				\
				K_THREAD_STACK_SIZEOF(udc_sam0_stack_##n),	\
				udc_sam0_thread_##n,				\
				(void *)dev, NULL, NULL,			\
				K_PRIO_COOP(CONFIG_UDC_SAM0_THREAD_PRIORITY),	\
				K_ESSENTIAL,					\
				K_NO_WAIT);					\
		k_thread_name_set(&priv->thread_data, dev->name);		\
	}									\
										\
	static struct udc_ep_config						\
		ep_cfg_out[DT_INST_PROP(n, num_bidir_endpoints)];		\
	static struct udc_ep_config						\
		ep_cfg_in[DT_INST_PROP(n, num_bidir_endpoints)];		\
										\
	static const struct udc_sam0_config udc_sam0_config_##n = {		\
		.base = (UsbDevice *)DT_INST_REG_ADDR(n),			\
		.bdt = sam0_bdt_##n,						\
		.num_of_eps = DT_INST_PROP(n, num_bidir_endpoints),		\
		.ep_cfg_in = ep_cfg_out,					\
		.ep_cfg_out = ep_cfg_in,					\
		.irq_enable_func = udc_sam0_irq_enable_func_##n,		\
		.irq_disable_func = udc_sam0_irq_disable_func_##n,		\
		.pcfg = UDC_SAM0_PINCTRL_DT_INST_DEV_CONFIG_GET(n),		\
		.make_thread = udc_sam0_make_thread_##n,			\
	};									\
										\
	static struct udc_sam0_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, udc_sam0_driver_preinit, NULL,			\
			      &udc_data_##n, &udc_sam0_config_##n,		\
			      POST_KERNEL, CONFIG_KERNEL_INIT_PRIORITY_DEVICE,	\
			      &udc_sam0_api);

DT_INST_FOREACH_STATUS_OKAY(UDC_SAM0_DEVICE_DEFINE)