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