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         GNSS_TYPE_MTK,
  26
  27         GNSS_TYPE_COUNT
  28 };
  29
  30 struct gnss_operations {
  31         int (*open)(struct gnss_device *gdev);
  32         void (*close)(struct gnss_device *gdev);
  33         int (*write_raw)(struct gnss_device *gdev, const unsigned char *buf,
  34                                 size_t count);
  35 };
  36
  37 struct gnss_device {
  38         struct device dev;
  39         struct cdev cdev;
  40         int id;
  41
  42         enum gnss_type type;
  43         unsigned long flags;
  44
  45         struct rw_semaphore rwsem;
  46         const struct gnss_operations *ops;
  47         unsigned int count;
  48         unsigned int disconnected:1;
  49
  50         struct mutex read_mutex;
  51         struct kfifo read_fifo;
  52         wait_queue_head_t read_queue;
  53
  54         struct mutex write_mutex;
  55         char *write_buf;
  56 };
  57
  58 struct gnss_device *gnss_allocate_device(struct device *parent);
  59 void gnss_put_device(struct gnss_device *gdev);
  60 int gnss_register_device(struct gnss_device *gdev);
  61 void gnss_deregister_device(struct gnss_device *gdev);
  62
  63 int gnss_insert_raw(struct gnss_device *gdev, const unsigned char *buf,
  64                         size_t count);
  65
  66 static inline void gnss_set_drvdata(struct gnss_device *gdev, void *data)
  67 {
  68         dev_set_drvdata(&gdev->dev, data);
  69 }
  70
  71 static inline void *gnss_get_drvdata(struct gnss_device *gdev)
  72 {
  73         return dev_get_drvdata(&gdev->dev);
  74 }
  75
  76 #endif /* _LINUX_GNSS_H */