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 
gnss_set_drvdata(struct gnss_device * gdev,void * data)66 static inline void gnss_set_drvdata(struct gnss_device *gdev, void *data)
67 {
68 	dev_set_drvdata(&gdev->dev, data);
69 }
70 
gnss_get_drvdata(struct gnss_device * gdev)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 */
77