LXR linux/drivers/staging/fieldbus/fieldbus

   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
  13enum fieldbus_dev_type {
  14        FIELDBUS_DEV_TYPE_UNKNOWN = 0,
  15        FIELDBUS_DEV_TYPE_PROFINET,
  16};
  17
  18enum 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 */
  46struct 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 **/
  77void 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 **/
  84int __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 **/
  92void 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 **/
  99void fieldbus_dev_online_changed(struct fieldbus_dev *fb, bool online);
 100
 101#else /* IS_ENABLED(CONFIG_FIELDBUS_DEV) */
 102
 103static inline void fieldbus_dev_unregister(struct fieldbus_dev *fb) {}
 104static inline int __must_check fieldbus_dev_register(struct fieldbus_dev *fb)
 105{
 106        return -ENOTSUPP;
 107}
 108
 109static inline void fieldbus_dev_area_updated(struct fieldbus_dev *fb) {}
 110static 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