// SPDX-License-Identifier: GPL-2.0-or-later

  /*

   */
  
  #include <linux/init.h>

  #include <linux/slab.h>

  #include <linux/usb.h>
  
  #include "usbaudio.h"
  #include "helper.h"

  #include "quirks.h"

  
  /*
   * combine bytes and get an integer value
   */
  unsigned int snd_usb_combine_bytes(unsigned char *bytes, int size)
  {
  	switch (size) {
  	case 1:  return *bytes;
  	case 2:  return combine_word(bytes);
  	case 3:  return combine_triple(bytes);
  	case 4:  return combine_quad(bytes);
  	default: return 0;
  	}
  }
  
  /*
   * parse descriptor buffer and return the pointer starting the given
   * descriptor type.
   */
  void *snd_usb_find_desc(void *descstart, int desclen, void *after, u8 dtype)
  {
  	u8 *p, *end, *next;
  
  	p = descstart;
  	end = p + desclen;
  	for (; p < end;) {
  		if (p[0] < 2)
  			return NULL;
  		next = p + p[0];
  		if (next > end)
  			return NULL;
  		if (p[1] == dtype && (!after || (void *)p > after)) {
  			return p;
  		}
  		p = next;
  	}
  	return NULL;
  }
  
  /*
   * find a class-specified interface descriptor with the given subtype.
   */
  void *snd_usb_find_csint_desc(void *buffer, int buflen, void *after, u8 dsubtype)
  {
  	unsigned char *p = after;
  
  	while ((p = snd_usb_find_desc(buffer, buflen, p,
  				      USB_DT_CS_INTERFACE)) != NULL) {
  		if (p[0] >= 3 && p[2] == dsubtype)
  			return p;
  	}
  	return NULL;
  }

  /* check the validity of pipe and EP types */
  int snd_usb_pipe_sanity_check(struct usb_device *dev, unsigned int pipe)
  {
  	static const int pipetypes[4] = {
  		PIPE_CONTROL, PIPE_ISOCHRONOUS, PIPE_BULK, PIPE_INTERRUPT
  	};
  	struct usb_host_endpoint *ep;
  
  	ep = usb_pipe_endpoint(dev, pipe);

  	if (!ep || usb_pipetype(pipe) != pipetypes[usb_endpoint_type(&ep->desc)])

  		return -EINVAL;
  	return 0;
  }

  /*
   * Wrapper for usb_control_msg().
   * Allocates a temp buffer to prevent dmaing from/to the stack.
   */
  int snd_usb_ctl_msg(struct usb_device *dev, unsigned int pipe, __u8 request,
  		    __u8 requesttype, __u16 value, __u16 index, void *data,

  		    __u16 size)

  {
  	int err;
  	void *buf = NULL;

  	int timeout;

  	if (snd_usb_pipe_sanity_check(dev, pipe))
  		return -EINVAL;

  	if (size > 0) {
  		buf = kmemdup(data, size, GFP_KERNEL);
  		if (!buf)
  			return -ENOMEM;
  	}

  
  	if (requesttype & USB_DIR_IN)
  		timeout = USB_CTRL_GET_TIMEOUT;
  	else
  		timeout = USB_CTRL_SET_TIMEOUT;

  	err = usb_control_msg(dev, pipe, request, requesttype,

  			      value, index, buf, size, timeout);

  	if (size > 0) {
  		memcpy(data, buf, size);
  		kfree(buf);
  	}

  
  	snd_usb_ctl_msg_quirk(dev, pipe, request, requesttype,
  			      value, index, data, size);

  	return err;
  }
  
  unsigned char snd_usb_parse_datainterval(struct snd_usb_audio *chip,
  					 struct usb_host_interface *alts)
  {

  	switch (snd_usb_get_speed(chip->dev)) {
  	case USB_SPEED_HIGH:

  	case USB_SPEED_WIRELESS:

  	case USB_SPEED_SUPER:

  	case USB_SPEED_SUPER_PLUS:

  		if (get_endpoint(alts, 0)->bInterval >= 1 &&
  		    get_endpoint(alts, 0)->bInterval <= 4)
  			return get_endpoint(alts, 0)->bInterval - 1;
  		break;
  	default:
  		break;
  	}
  	return 0;

  }