include/linux/gnss.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * GNSS receiver support
   4  *
   5  * Copyright (C) 2018 Johan Hovold <johan@kernel.org>
   6  */
   7
   8 #ifndef _LINUX_GNSS_H
   9 #define _LINUX_GNSS_H
  10
  11 #include <linux/cdev.h>
  12 #include <linux/device.h>
  13 #include <linux/kfifo.h>
  14 #include <linux/mutex.h>
  15 #include <linux/rwsem.h>
  16 #include <linux/types.h>
  17 #include <linux/wait.h>
  18
  19 struct gnss_device;
  20
  21 enum gnss_type {
  22         GNSS_TYPE_NMEA = 0,
  23         GNSS_TYPE_SIRF,
  24         GNSS_TYPE_UBX,
  25
  26         GNSS_TYPE_COUNT
  27 };
  28
  29 struct gnss_operations {
  30         int (*open)(struct gnss_device *gdev);
  31         void (*close)(struct gnss_device *gdev);
  32         int (*write_raw)(struct gnss_device *gdev, const unsigned char *buf,
  33                                 size_t count);
  34 };
  35
  36 struct gnss_device {
  37         struct device dev;
  38         struct cdev cdev;
  39         int id;
  40
  41         enum gnss_type type;
  42         unsigned long flags;
  43
  44         struct rw_semaphore rwsem;
  45         const struct gnss_operations *ops;
  46         unsigned int count;
  47         unsigned int disconnected:1;
  48
  49         struct mutex read_mutex;
  50         struct kfifo read_fifo;
  51         wait_queue_head_t read_queue;
  52
  53         struct mutex write_mutex;
  54         char *write_buf;
  55 };
  56
  57 struct gnss_device *gnss_allocate_device(struct device *parent);
  58 void gnss_put_device(struct gnss_device *gdev);
  59 int gnss_register_device(struct gnss_device *gdev);
  60 void gnss_deregister_device(struct gnss_device *gdev);
  61
  62 int gnss_insert_raw(struct gnss_device *gdev, const unsigned char *buf,
  63                         size_t count);
  64
  65 static inline void gnss_set_drvdata(struct gnss_device *gdev, void *data)
  66 {
  67         dev_set_drvdata(&gdev->dev, data);
  68 }
  69
  70 static inline void *gnss_get_drvdata(struct gnss_device *gdev)
  71 {
  72         return dev_get_drvdata(&gdev->dev);
  73 }
  74
  75 #endif /* _LINUX_GNSS_H */