/* SPDX-License-Identifier: GPL-2.0 */
  /*
   * GNSS receiver support
   *
   * Copyright (C) 2018 Johan Hovold <johan@kernel.org>
   */
  
  #ifndef _LINUX_GNSS_H
  #define _LINUX_GNSS_H
  
  #include <linux/cdev.h>
  #include <linux/device.h>
  #include <linux/kfifo.h>
  #include <linux/mutex.h>
  #include <linux/rwsem.h>
  #include <linux/types.h>
  #include <linux/wait.h>
  
  struct gnss_device;

  enum gnss_type {
  	GNSS_TYPE_NMEA = 0,
  	GNSS_TYPE_SIRF,
  	GNSS_TYPE_UBX,

  	GNSS_TYPE_MTK,

  
  	GNSS_TYPE_COUNT
  };

  struct gnss_operations {
  	int (*open)(struct gnss_device *gdev);
  	void (*close)(struct gnss_device *gdev);
  	int (*write_raw)(struct gnss_device *gdev, const unsigned char *buf,
  				size_t count);
  };
  
  struct gnss_device {
  	struct device dev;
  	struct cdev cdev;
  	int id;

  	enum gnss_type type;

  	unsigned long flags;
  
  	struct rw_semaphore rwsem;
  	const struct gnss_operations *ops;
  	unsigned int count;
  	unsigned int disconnected:1;
  
  	struct mutex read_mutex;
  	struct kfifo read_fifo;
  	wait_queue_head_t read_queue;
  
  	struct mutex write_mutex;
  	char *write_buf;
  };
  
  struct gnss_device *gnss_allocate_device(struct device *parent);
  void gnss_put_device(struct gnss_device *gdev);
  int gnss_register_device(struct gnss_device *gdev);
  void gnss_deregister_device(struct gnss_device *gdev);
  
  int gnss_insert_raw(struct gnss_device *gdev, const unsigned char *buf,
  			size_t count);
  
  static inline void gnss_set_drvdata(struct gnss_device *gdev, void *data)
  {
  	dev_set_drvdata(&gdev->dev, data);
  }
  
  static inline void *gnss_get_drvdata(struct gnss_device *gdev)
  {
  	return dev_get_drvdata(&gdev->dev);
  }
  
  #endif /* _LINUX_GNSS_H */