v4.19.13 snapshot.
diff --git a/drivers/char/scx200_gpio.c b/drivers/char/scx200_gpio.c
new file mode 100644
index 0000000..903761b
--- /dev/null
+++ b/drivers/char/scx200_gpio.c
@@ -0,0 +1,132 @@
+/* linux/drivers/char/scx200_gpio.c
+
+ National Semiconductor SCx200 GPIO driver. Allows a user space
+ process to play with the GPIO pins.
+
+ Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com> */
+
+#include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/uaccess.h>
+#include <asm/io.h>
+
+#include <linux/types.h>
+#include <linux/cdev.h>
+
+#include <linux/scx200_gpio.h>
+#include <linux/nsc_gpio.h>
+
+#define DRVNAME "scx200_gpio"
+
+static struct platform_device *pdev;
+
+MODULE_AUTHOR("Christer Weinigel <wingel@nano-system.com>");
+MODULE_DESCRIPTION("NatSemi/AMD SCx200 GPIO Pin Driver");
+MODULE_LICENSE("GPL");
+
+static int major = 0; /* default to dynamic major */
+module_param(major, int, 0);
+MODULE_PARM_DESC(major, "Major device number");
+
+#define MAX_PINS 32 /* 64 later, when known ok */
+
+struct nsc_gpio_ops scx200_gpio_ops = {
+ .owner = THIS_MODULE,
+ .gpio_config = scx200_gpio_configure,
+ .gpio_dump = nsc_gpio_dump,
+ .gpio_get = scx200_gpio_get,
+ .gpio_set = scx200_gpio_set,
+ .gpio_change = scx200_gpio_change,
+ .gpio_current = scx200_gpio_current
+};
+EXPORT_SYMBOL_GPL(scx200_gpio_ops);
+
+static int scx200_gpio_open(struct inode *inode, struct file *file)
+{
+ unsigned m = iminor(inode);
+ file->private_data = &scx200_gpio_ops;
+
+ if (m >= MAX_PINS)
+ return -EINVAL;
+ return nonseekable_open(inode, file);
+}
+
+static int scx200_gpio_release(struct inode *inode, struct file *file)
+{
+ return 0;
+}
+
+static const struct file_operations scx200_gpio_fileops = {
+ .owner = THIS_MODULE,
+ .write = nsc_gpio_write,
+ .read = nsc_gpio_read,
+ .open = scx200_gpio_open,
+ .release = scx200_gpio_release,
+ .llseek = no_llseek,
+};
+
+static struct cdev scx200_gpio_cdev; /* use 1 cdev for all pins */
+
+static int __init scx200_gpio_init(void)
+{
+ int rc;
+ dev_t devid;
+
+ if (!scx200_gpio_present()) {
+ printk(KERN_ERR DRVNAME ": no SCx200 gpio present\n");
+ return -ENODEV;
+ }
+
+ /* support dev_dbg() with pdev->dev */
+ pdev = platform_device_alloc(DRVNAME, 0);
+ if (!pdev)
+ return -ENOMEM;
+
+ rc = platform_device_add(pdev);
+ if (rc)
+ goto undo_malloc;
+
+ /* nsc_gpio uses dev_dbg(), so needs this */
+ scx200_gpio_ops.dev = &pdev->dev;
+
+ if (major) {
+ devid = MKDEV(major, 0);
+ rc = register_chrdev_region(devid, MAX_PINS, "scx200_gpio");
+ } else {
+ rc = alloc_chrdev_region(&devid, 0, MAX_PINS, "scx200_gpio");
+ major = MAJOR(devid);
+ }
+ if (rc < 0) {
+ dev_err(&pdev->dev, "SCx200 chrdev_region err: %d\n", rc);
+ goto undo_platform_device_add;
+ }
+
+ cdev_init(&scx200_gpio_cdev, &scx200_gpio_fileops);
+ cdev_add(&scx200_gpio_cdev, devid, MAX_PINS);
+
+ return 0; /* succeed */
+
+undo_platform_device_add:
+ platform_device_del(pdev);
+undo_malloc:
+ platform_device_put(pdev);
+
+ return rc;
+}
+
+static void __exit scx200_gpio_cleanup(void)
+{
+ cdev_del(&scx200_gpio_cdev);
+ /* cdev_put(&scx200_gpio_cdev); */
+
+ unregister_chrdev_region(MKDEV(major, 0), MAX_PINS);
+ platform_device_unregister(pdev);
+}
+
+module_init(scx200_gpio_init);
+module_exit(scx200_gpio_cleanup);