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![Ding Xiang](/assets/img/avatar_default.png)
Use kobj_to_dev() instead of container_of() Signed-off-by: Ding Xiang <dingxiang@cmss.chinamobile.com> Link: https://lore.kernel.org/r/20201117025933.668938-1-dingxiang@cmss.chinamobile.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
348 lines
8 KiB
C
348 lines
8 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Fieldbus Device Driver Core
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*
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*/
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#include <linux/mutex.h>
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#include <linux/module.h>
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#include <linux/device.h>
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#include <linux/idr.h>
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#include <linux/fs.h>
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#include <linux/slab.h>
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#include <linux/poll.h>
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/* move to <linux/fieldbus_dev.h> when taking this out of staging */
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#include "fieldbus_dev.h"
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/* Maximum number of fieldbus devices */
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#define MAX_FIELDBUSES 32
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/* the dev_t structure to store the dynamically allocated fieldbus devices */
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static dev_t fieldbus_devt;
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static DEFINE_IDA(fieldbus_ida);
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static DEFINE_MUTEX(fieldbus_mtx);
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static ssize_t online_show(struct device *dev, struct device_attribute *attr,
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char *buf)
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{
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struct fieldbus_dev *fb = dev_get_drvdata(dev);
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return sprintf(buf, "%d\n", !!fb->online);
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}
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static DEVICE_ATTR_RO(online);
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static ssize_t enabled_show(struct device *dev, struct device_attribute *attr,
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char *buf)
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{
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struct fieldbus_dev *fb = dev_get_drvdata(dev);
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if (!fb->enable_get)
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return -EINVAL;
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return sprintf(buf, "%d\n", !!fb->enable_get(fb));
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}
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static ssize_t enabled_store(struct device *dev, struct device_attribute *attr,
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const char *buf, size_t n)
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{
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struct fieldbus_dev *fb = dev_get_drvdata(dev);
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bool value;
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int ret;
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if (!fb->simple_enable_set)
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return -ENOTSUPP;
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ret = kstrtobool(buf, &value);
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if (ret)
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return ret;
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ret = fb->simple_enable_set(fb, value);
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if (ret < 0)
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return ret;
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return n;
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}
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static DEVICE_ATTR_RW(enabled);
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static ssize_t card_name_show(struct device *dev, struct device_attribute *attr,
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char *buf)
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{
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struct fieldbus_dev *fb = dev_get_drvdata(dev);
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/*
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* card_name was provided by child driver, could potentially be long.
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* protect against buffer overrun.
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*/
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return snprintf(buf, PAGE_SIZE, "%s\n", fb->card_name);
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}
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static DEVICE_ATTR_RO(card_name);
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static ssize_t read_area_size_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct fieldbus_dev *fb = dev_get_drvdata(dev);
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return sprintf(buf, "%zu\n", fb->read_area_sz);
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}
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static DEVICE_ATTR_RO(read_area_size);
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static ssize_t write_area_size_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct fieldbus_dev *fb = dev_get_drvdata(dev);
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return sprintf(buf, "%zu\n", fb->write_area_sz);
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}
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static DEVICE_ATTR_RO(write_area_size);
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static ssize_t fieldbus_id_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct fieldbus_dev *fb = dev_get_drvdata(dev);
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return fb->fieldbus_id_get(fb, buf, PAGE_SIZE);
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}
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static DEVICE_ATTR_RO(fieldbus_id);
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static ssize_t fieldbus_type_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct fieldbus_dev *fb = dev_get_drvdata(dev);
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const char *t;
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switch (fb->fieldbus_type) {
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case FIELDBUS_DEV_TYPE_PROFINET:
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t = "profinet";
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break;
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default:
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t = "unknown";
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break;
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}
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return sprintf(buf, "%s\n", t);
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}
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static DEVICE_ATTR_RO(fieldbus_type);
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static struct attribute *fieldbus_attrs[] = {
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&dev_attr_enabled.attr,
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&dev_attr_card_name.attr,
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&dev_attr_fieldbus_id.attr,
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&dev_attr_read_area_size.attr,
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&dev_attr_write_area_size.attr,
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&dev_attr_online.attr,
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&dev_attr_fieldbus_type.attr,
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NULL,
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};
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static umode_t fieldbus_is_visible(struct kobject *kobj, struct attribute *attr,
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int n)
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{
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struct device *dev = kobj_to_dev(kobj);
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struct fieldbus_dev *fb = dev_get_drvdata(dev);
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umode_t mode = attr->mode;
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if (attr == &dev_attr_enabled.attr) {
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mode = 0;
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if (fb->enable_get)
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mode |= 0444;
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if (fb->simple_enable_set)
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mode |= 0200;
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}
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return mode;
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}
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static const struct attribute_group fieldbus_group = {
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.attrs = fieldbus_attrs,
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.is_visible = fieldbus_is_visible,
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};
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__ATTRIBUTE_GROUPS(fieldbus);
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static struct class fieldbus_class = {
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.name = "fieldbus_dev",
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.owner = THIS_MODULE,
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.dev_groups = fieldbus_groups,
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};
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struct fb_open_file {
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struct fieldbus_dev *fbdev;
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int dc_event;
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};
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static int fieldbus_open(struct inode *inode, struct file *filp)
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{
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struct fb_open_file *of;
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struct fieldbus_dev *fbdev = container_of(inode->i_cdev,
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struct fieldbus_dev,
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cdev);
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of = kzalloc(sizeof(*of), GFP_KERNEL);
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if (!of)
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return -ENOMEM;
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of->fbdev = fbdev;
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filp->private_data = of;
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return 0;
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}
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static int fieldbus_release(struct inode *node, struct file *filp)
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{
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struct fb_open_file *of = filp->private_data;
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kfree(of);
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return 0;
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}
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static ssize_t fieldbus_read(struct file *filp, char __user *buf, size_t size,
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loff_t *offset)
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{
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struct fb_open_file *of = filp->private_data;
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struct fieldbus_dev *fbdev = of->fbdev;
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of->dc_event = fbdev->dc_event;
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return fbdev->read_area(fbdev, buf, size, offset);
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}
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static ssize_t fieldbus_write(struct file *filp, const char __user *buf,
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size_t size, loff_t *offset)
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{
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struct fb_open_file *of = filp->private_data;
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struct fieldbus_dev *fbdev = of->fbdev;
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return fbdev->write_area(fbdev, buf, size, offset);
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}
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static __poll_t fieldbus_poll(struct file *filp, poll_table *wait)
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{
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struct fb_open_file *of = filp->private_data;
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struct fieldbus_dev *fbdev = of->fbdev;
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__poll_t mask = EPOLLIN | EPOLLRDNORM | EPOLLOUT | EPOLLWRNORM;
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poll_wait(filp, &fbdev->dc_wq, wait);
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/* data changed ? */
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if (fbdev->dc_event != of->dc_event)
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mask |= EPOLLPRI | EPOLLERR;
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return mask;
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}
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static const struct file_operations fieldbus_fops = {
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.open = fieldbus_open,
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.release = fieldbus_release,
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.read = fieldbus_read,
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.write = fieldbus_write,
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.poll = fieldbus_poll,
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.llseek = generic_file_llseek,
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.owner = THIS_MODULE,
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};
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void fieldbus_dev_area_updated(struct fieldbus_dev *fb)
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{
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fb->dc_event++;
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wake_up_all(&fb->dc_wq);
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}
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EXPORT_SYMBOL_GPL(fieldbus_dev_area_updated);
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void fieldbus_dev_online_changed(struct fieldbus_dev *fb, bool online)
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{
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fb->online = online;
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kobject_uevent(&fb->dev->kobj, KOBJ_CHANGE);
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}
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EXPORT_SYMBOL_GPL(fieldbus_dev_online_changed);
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static void __fieldbus_dev_unregister(struct fieldbus_dev *fb)
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{
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if (!fb)
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return;
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device_destroy(&fieldbus_class, fb->cdev.dev);
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cdev_del(&fb->cdev);
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ida_simple_remove(&fieldbus_ida, fb->id);
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}
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void fieldbus_dev_unregister(struct fieldbus_dev *fb)
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{
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mutex_lock(&fieldbus_mtx);
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__fieldbus_dev_unregister(fb);
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mutex_unlock(&fieldbus_mtx);
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}
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EXPORT_SYMBOL_GPL(fieldbus_dev_unregister);
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static int __fieldbus_dev_register(struct fieldbus_dev *fb)
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{
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dev_t devno;
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int err;
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if (!fb)
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return -EINVAL;
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if (!fb->read_area || !fb->write_area || !fb->fieldbus_id_get)
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return -EINVAL;
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fb->id = ida_simple_get(&fieldbus_ida, 0, MAX_FIELDBUSES, GFP_KERNEL);
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if (fb->id < 0)
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return fb->id;
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devno = MKDEV(MAJOR(fieldbus_devt), fb->id);
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init_waitqueue_head(&fb->dc_wq);
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cdev_init(&fb->cdev, &fieldbus_fops);
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err = cdev_add(&fb->cdev, devno, 1);
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if (err) {
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pr_err("fieldbus_dev%d unable to add device %d:%d\n",
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fb->id, MAJOR(fieldbus_devt), fb->id);
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goto err_cdev;
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}
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fb->dev = device_create(&fieldbus_class, fb->parent, devno, fb,
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"fieldbus_dev%d", fb->id);
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if (IS_ERR(fb->dev)) {
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err = PTR_ERR(fb->dev);
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goto err_dev_create;
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}
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return 0;
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err_dev_create:
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cdev_del(&fb->cdev);
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err_cdev:
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ida_simple_remove(&fieldbus_ida, fb->id);
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return err;
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}
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int fieldbus_dev_register(struct fieldbus_dev *fb)
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{
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int err;
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mutex_lock(&fieldbus_mtx);
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err = __fieldbus_dev_register(fb);
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mutex_unlock(&fieldbus_mtx);
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return err;
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}
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EXPORT_SYMBOL_GPL(fieldbus_dev_register);
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static int __init fieldbus_init(void)
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{
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int err;
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err = class_register(&fieldbus_class);
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if (err < 0) {
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pr_err("fieldbus_dev: could not register class\n");
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return err;
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}
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err = alloc_chrdev_region(&fieldbus_devt, 0,
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MAX_FIELDBUSES, "fieldbus_dev");
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if (err < 0) {
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pr_err("fieldbus_dev: unable to allocate char dev region\n");
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goto err_alloc;
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}
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return 0;
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err_alloc:
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class_unregister(&fieldbus_class);
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return err;
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}
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static void __exit fieldbus_exit(void)
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{
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unregister_chrdev_region(fieldbus_devt, MAX_FIELDBUSES);
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class_unregister(&fieldbus_class);
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ida_destroy(&fieldbus_ida);
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}
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subsys_initcall(fieldbus_init);
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module_exit(fieldbus_exit);
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MODULE_AUTHOR("Sven Van Asbroeck <TheSven73@gmail.com>");
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MODULE_AUTHOR("Jonathan Stiles <jonathans@arcx.com>");
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MODULE_DESCRIPTION("Fieldbus Device Driver Core");
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MODULE_LICENSE("GPL v2");
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