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) */ 102 103 static inline void fieldbus_dev_unregister(struct fieldbus_dev *fb) {} 104 static inline int __must_check fieldbus_dev_register(struct fieldbus_dev *fb) 105 { 106 return -ENOTSUPP; 107 } 108 109 static inline void fieldbus_dev_area_updated(struct fieldbus_dev *fb) {} 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