1 files changed, 351 insertions, 0 deletions

diff --git a/drivers/staging/fieldbus/dev_core.c b/drivers/staging/fieldbus/dev_core.c
new file mode 100644
index 000000000000..60b85140675a
--- /dev/null
+++ b/drivers/staging/fieldbus/dev_core.c
@@ -0,0 +1,351 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Fieldbus Device Driver Core
+ *
+ */
+
+#include <linux/mutex.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/idr.h>
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <linux/poll.h>
+
+/* move to <linux/fieldbus_dev.h> when taking this out of staging */
+#include "fieldbus_dev.h"
+
+/* Maximum number of fieldbus devices */
+#define MAX_FIELDBUSES		32
+
+/* the dev_t structure to store the dynamically allocated fieldbus devices */
+static dev_t fieldbus_devt;
+static DEFINE_IDA(fieldbus_ida);
+static DEFINE_MUTEX(fieldbus_mtx);
+
+static const char ctrl_enabled[] = "enabled";
+static const char ctrl_disabled[] = "disabled";
+
+static ssize_t online_show(struct device *dev, struct device_attribute *attr,
+			   char *buf)
+{
+	struct fieldbus_dev *fb = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%d\n", !!fb->online);
+}
+static DEVICE_ATTR_RO(online);
+
+static ssize_t enabled_show(struct device *dev, struct device_attribute *attr,
+			    char *buf)
+{
+	struct fieldbus_dev *fb = dev_get_drvdata(dev);
+
+	if (!fb->enable_get)
+		return -EINVAL;
+	return sprintf(buf, "%d\n", !!fb->enable_get(fb));
+}
+
+static ssize_t enabled_store(struct device *dev, struct device_attribute *attr,
+			     const char *buf, size_t n)
+{
+	struct fieldbus_dev *fb = dev_get_drvdata(dev);
+	bool value;
+	int ret;
+
+	if (!fb->simple_enable_set)
+		return -ENOTSUPP;
+	ret = kstrtobool(buf, &value);
+	if (ret)
+		return ret;
+	ret = fb->simple_enable_set(fb, value);
+	if (ret < 0)
+		return ret;
+	return n;
+}
+static DEVICE_ATTR_RW(enabled);
+
+static ssize_t card_name_show(struct device *dev, struct device_attribute *attr,
+			      char *buf)
+{
+	struct fieldbus_dev *fb = dev_get_drvdata(dev);
+
+	/*
+	 * card_name was provided by child driver, could potentially be long.
+	 * protect against buffer overrun.
+	 */
+	return snprintf(buf, PAGE_SIZE, "%s\n", fb->card_name);
+}
+static DEVICE_ATTR_RO(card_name);
+
+static ssize_t read_area_size_show(struct device *dev,
+				   struct device_attribute *attr, char *buf)
+{
+	struct fieldbus_dev *fb = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%zu\n", fb->read_area_sz);
+}
+static DEVICE_ATTR_RO(read_area_size);
+
+static ssize_t write_area_size_show(struct device *dev,
+				    struct device_attribute *attr, char *buf)
+{
+	struct fieldbus_dev *fb = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%zu\n", fb->write_area_sz);
+}
+static DEVICE_ATTR_RO(write_area_size);
+
+static ssize_t fieldbus_id_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct fieldbus_dev *fb = dev_get_drvdata(dev);
+
+	return fb->fieldbus_id_get(fb, buf, PAGE_SIZE);
+}
+static DEVICE_ATTR_RO(fieldbus_id);
+
+static ssize_t fieldbus_type_show(struct device *dev,
+				  struct device_attribute *attr, char *buf)
+{
+	struct fieldbus_dev *fb = dev_get_drvdata(dev);
+	const char *t;
+
+	switch (fb->fieldbus_type) {
+	case FIELDBUS_DEV_TYPE_PROFINET:
+		t = "profinet";
+		break;
+	default:
+		t = "unknown";
+		break;
+	}
+
+	return sprintf(buf, "%s\n", t);
+}
+static DEVICE_ATTR_RO(fieldbus_type);
+
+static struct attribute *fieldbus_attrs[] = {
+	&dev_attr_enabled.attr,
+	&dev_attr_card_name.attr,
+	&dev_attr_fieldbus_id.attr,
+	&dev_attr_read_area_size.attr,
+	&dev_attr_write_area_size.attr,
+	&dev_attr_online.attr,
+	&dev_attr_fieldbus_type.attr,
+	NULL,
+};
+
+static umode_t fieldbus_is_visible(struct kobject *kobj, struct attribute *attr,
+				   int n)
+{
+	struct device *dev = container_of(kobj, struct device, kobj);
+	struct fieldbus_dev *fb = dev_get_drvdata(dev);
+	umode_t mode = attr->mode;
+
+	if (attr == &dev_attr_enabled.attr) {
+		mode = 0;
+		if (fb->enable_get)
+			mode |= 0444;
+		if (fb->simple_enable_set)
+			mode |= 0200;
+	}
+
+	return mode;
+}
+
+static const struct attribute_group fieldbus_group = {
+	.attrs = fieldbus_attrs,
+	.is_visible = fieldbus_is_visible,
+};
+__ATTRIBUTE_GROUPS(fieldbus);
+
+static struct class fieldbus_class = {
+	.name =		"fieldbus_dev",
+	.owner =	THIS_MODULE,
+	.dev_groups =	fieldbus_groups,
+};
+
+struct fb_open_file {
+	struct fieldbus_dev *fbdev;
+	int dc_event;
+};
+
+static int fieldbus_open(struct inode *inode, struct file *filp)
+{
+	struct fb_open_file *of;
+	struct fieldbus_dev *fbdev = container_of(inode->i_cdev,
+						struct fieldbus_dev,
+						cdev);
+
+	of = kzalloc(sizeof(*of), GFP_KERNEL);
+	if (!of)
+		return -ENOMEM;
+	of->fbdev = fbdev;
+	filp->private_data = of;
+	return 0;
+}
+
+static int fieldbus_release(struct inode *node, struct file *filp)
+{
+	struct fb_open_file *of = filp->private_data;
+
+	kfree(of);
+	return 0;
+}
+
+static ssize_t fieldbus_read(struct file *filp, char __user *buf, size_t size,
+			     loff_t *offset)
+{
+	struct fb_open_file *of = filp->private_data;
+	struct fieldbus_dev *fbdev = of->fbdev;
+
+	of->dc_event = fbdev->dc_event;
+	return fbdev->read_area(fbdev, buf, size, offset);
+}
+
+static ssize_t fieldbus_write(struct file *filp, const char __user *buf,
+			      size_t size, loff_t *offset)
+{
+	struct fb_open_file *of = filp->private_data;
+	struct fieldbus_dev *fbdev = of->fbdev;
+
+	return fbdev->write_area(fbdev, buf, size, offset);
+}
+
+static unsigned int fieldbus_poll(struct file *filp, poll_table *wait)
+{
+	struct fb_open_file *of = filp->private_data;
+	struct fieldbus_dev *fbdev = of->fbdev;
+	unsigned int mask = POLLIN | POLLRDNORM | POLLOUT | POLLWRNORM;
+
+	poll_wait(filp, &fbdev->dc_wq, wait);
+	/* data changed ? */
+	if (fbdev->dc_event != of->dc_event)
+		mask |= POLLPRI | POLLERR;
+	return mask;
+}
+
+static const struct file_operations fieldbus_fops = {
+	.open		= fieldbus_open,
+	.release	= fieldbus_release,
+	.read		= fieldbus_read,
+	.write		= fieldbus_write,
+	.poll		= fieldbus_poll,
+	.llseek		= generic_file_llseek,
+	.owner		= THIS_MODULE,
+};
+
+void fieldbus_dev_area_updated(struct fieldbus_dev *fb)
+{
+	fb->dc_event++;
+	wake_up_all(&fb->dc_wq);
+}
+EXPORT_SYMBOL_GPL(fieldbus_dev_area_updated);
+
+void fieldbus_dev_online_changed(struct fieldbus_dev *fb, bool online)
+{
+	fb->online = online;
+	kobject_uevent(&fb->dev->kobj, KOBJ_CHANGE);
+}
+EXPORT_SYMBOL_GPL(fieldbus_dev_online_changed);
+
+static void __fieldbus_dev_unregister(struct fieldbus_dev *fb)
+{
+	if (!fb)
+		return;
+	device_destroy(&fieldbus_class, fb->cdev.dev);
+	cdev_del(&fb->cdev);
+	ida_simple_remove(&fieldbus_ida, fb->id);
+}
+
+void fieldbus_dev_unregister(struct fieldbus_dev *fb)
+{
+	mutex_lock(&fieldbus_mtx);
+	__fieldbus_dev_unregister(fb);
+	mutex_unlock(&fieldbus_mtx);
+}
+EXPORT_SYMBOL_GPL(fieldbus_dev_unregister);
+
+static int __fieldbus_dev_register(struct fieldbus_dev *fb)
+{
+	dev_t devno;
+	int err;
+
+	if (!fb)
+		return -EINVAL;
+	if (!fb->read_area || !fb->write_area || !fb->fieldbus_id_get)
+		return -EINVAL;
+	fb->id = ida_simple_get(&fieldbus_ida, 0, MAX_FIELDBUSES, GFP_KERNEL);
+	if (fb->id < 0)
+		return fb->id;
+	devno = MKDEV(MAJOR(fieldbus_devt), fb->id);
+	init_waitqueue_head(&fb->dc_wq);
+	cdev_init(&fb->cdev, &fieldbus_fops);
+	err = cdev_add(&fb->cdev, devno, 1);
+	if (err) {
+		pr_err("fieldbus_dev%d unable to add device %d:%d\n",
+		       fb->id, MAJOR(fieldbus_devt), fb->id);
+		goto err_cdev;
+	}
+	fb->dev = device_create(&fieldbus_class, fb->parent, devno, fb,
+				"fieldbus_dev%d", fb->id);
+	if (IS_ERR(fb->dev)) {
+		err = PTR_ERR(fb->dev);
+		goto err_dev_create;
+	}
+	return 0;
+
+err_dev_create:
+	cdev_del(&fb->cdev);
+err_cdev:
+	ida_simple_remove(&fieldbus_ida, fb->id);
+	return err;
+}
+
+int fieldbus_dev_register(struct fieldbus_dev *fb)
+{
+	int err;
+
+	mutex_lock(&fieldbus_mtx);
+	err = __fieldbus_dev_register(fb);
+	mutex_unlock(&fieldbus_mtx);
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(fieldbus_dev_register);
+
+static int __init fieldbus_init(void)
+{
+	int err;
+
+	err = class_register(&fieldbus_class);
+	if (err < 0) {
+		pr_err("fieldbus_dev: could not register class\n");
+		return err;
+	}
+	err = alloc_chrdev_region(&fieldbus_devt, 0,
+				  MAX_FIELDBUSES, "fieldbus_dev");
+	if (err < 0) {
+		pr_err("fieldbus_dev: unable to allocate char dev region\n");
+		goto err_alloc;
+	}
+	return 0;
+
+err_alloc:
+	class_unregister(&fieldbus_class);
+	return err;
+}
+
+static void __exit fieldbus_exit(void)
+{
+	unregister_chrdev_region(fieldbus_devt, MAX_FIELDBUSES);
+	class_unregister(&fieldbus_class);
+	ida_destroy(&fieldbus_ida);
+}
+
+subsys_initcall(fieldbus_init);
+module_exit(fieldbus_exit);
+
+MODULE_AUTHOR("Sven Van Asbroeck <TheSven73@gmail.com>");
+MODULE_AUTHOR("Jonathan Stiles <jonathans@arcx.com>");
+MODULE_DESCRIPTION("Fieldbus Device Driver Core");
+MODULE_LICENSE("GPL v2");