1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * Fieldbus Device Driver Core
4 *
5 */
6
7 #ifndef __FIELDBUS_DEV_H
8 #define __FIELDBUS_DEV_H
9
10 #include <linux/cdev.h>
11 #include <linux/wait.h>
12
13 enum fieldbus_dev_type {
14 FIELDBUS_DEV_TYPE_UNKNOWN = 0,
15 FIELDBUS_DEV_TYPE_PROFINET,
16 };
17
18 enum fieldbus_dev_offl_mode {
19 FIELDBUS_DEV_OFFL_MODE_CLEAR = 0,
20 FIELDBUS_DEV_OFFL_MODE_FREEZE,
21 FIELDBUS_DEV_OFFL_MODE_SET
22 };
23
24 /**
25 * struct fieldbus_dev - Fieldbus device
26 * @read_area: [DRIVER] function to read the process data area of the
27 * device. same parameters/return values as
28 * the read function in struct file_operations
29 * @write_area: [DRIVER] function to write to the process data area of
30 * the device. same parameters/return values as
31 * the write function in struct file_operations
32 * @write_area_sz [DRIVER] size of the writable process data area
33 * @read_area_sz [DRIVER] size of the readable process data area
34 * @card_name [DRIVER] name of the card, e.g. "ACME Inc. profinet"
35 * @fieldbus_type [DRIVER] fieldbus type of this device, e.g.
36 * FIELDBUS_DEV_TYPE_PROFINET
37 * @enable_get [DRIVER] function which returns true if the card
38 * is enabled, false otherwise
39 * @fieldbus_id_get [DRIVER] function to retrieve the unique fieldbus id
40 * by which this device can be identified;
41 * return value follows the snprintf convention
42 * @simple_enable_set [DRIVER] (optional) function to enable the device
43 * according to its default settings
44 * @parent [DRIVER] (optional) the device's parent device
45 */
46 struct fieldbus_dev {
47 ssize_t (*read_area)(struct fieldbus_dev *fbdev, char __user *buf,
48 size_t size, loff_t *offset);
49 ssize_t (*write_area)(struct fieldbus_dev *fbdev,
50 const char __user *buf, size_t size,
51 loff_t *offset);
52 size_t write_area_sz, read_area_sz;
53 const char *card_name;
54 enum fieldbus_dev_type fieldbus_type;
55 bool (*enable_get)(struct fieldbus_dev *fbdev);
56 int (*fieldbus_id_get)(struct fieldbus_dev *fbdev, char *buf,
57 size_t max_size);
58 int (*simple_enable_set)(struct fieldbus_dev *fbdev, bool enable);
59 struct device *parent;
60
61 /* private data */
62 int id;
63 struct cdev cdev;
64 struct device *dev;
65 int dc_event;
66 wait_queue_head_t dc_wq;
67 bool online;
68 };
69
70 #if IS_ENABLED(CONFIG_FIELDBUS_DEV)
71
72 /**
73 * fieldbus_dev_unregister()
74 * - unregister a previously registered fieldbus device
75 * @fb: Device structure previously registered
76 **/
77 void fieldbus_dev_unregister(struct fieldbus_dev *fb);
78
79 /**
80 * fieldbus_dev_register()
81 * - register a device with the fieldbus device subsystem
82 * @fb: Device structure filled by the device driver
83 **/
84 int __must_check fieldbus_dev_register(struct fieldbus_dev *fb);
85
86 /**
87 * fieldbus_dev_area_updated()
88 * - notify the subsystem that an external fieldbus controller updated
89 * the process data area
90 * @fb: Device structure
91 **/
92 void fieldbus_dev_area_updated(struct fieldbus_dev *fb);
93
94 /**
95 * fieldbus_dev_online_changed()
96 * - notify the subsystem that the fieldbus online status changed
97 * @fb: Device structure
98 **/
99 void fieldbus_dev_online_changed(struct fieldbus_dev *fb, bool online);
100
101 #else /* IS_ENABLED(CONFIG_FIELDBUS_DEV) */
102
fieldbus_dev_unregister(struct fieldbus_dev * fb)103 static inline void fieldbus_dev_unregister(struct fieldbus_dev *fb) {}
fieldbus_dev_register(struct fieldbus_dev * fb)104 static inline int __must_check fieldbus_dev_register(struct fieldbus_dev *fb)
105 {
106 return -ENOTSUPP;
107 }
108
fieldbus_dev_area_updated(struct fieldbus_dev * fb)109 static inline void fieldbus_dev_area_updated(struct fieldbus_dev *fb) {}
fieldbus_dev_online_changed(struct fieldbus_dev * fb,bool online)110 static inline void fieldbus_dev_online_changed(struct fieldbus_dev *fb,
111 bool online) {}
112
113 #endif /* IS_ENABLED(CONFIG_FIELDBUS_DEV) */
114 #endif /* __FIELDBUS_DEV_H */
115