v4.19.13 snapshot.
diff --git a/drivers/char/nsc_gpio.c b/drivers/char/nsc_gpio.c
new file mode 100644
index 0000000..2a91bf0
--- /dev/null
+++ b/drivers/char/nsc_gpio.c
@@ -0,0 +1,139 @@
+/* linux/drivers/char/nsc_gpio.c
+
+ National Semiconductor common GPIO device-file/VFS methods.
+ Allows a user space process to control the GPIO pins.
+
+ Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com>
+ Copyright (c) 2005 Jim Cromie <jim.cromie@gmail.com>
+*/
+
+#include <linux/fs.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/nsc_gpio.h>
+#include <linux/platform_device.h>
+#include <linux/uaccess.h>
+#include <asm/io.h>
+
+#define NAME "nsc_gpio"
+
+void nsc_gpio_dump(struct nsc_gpio_ops *amp, unsigned index)
+{
+ /* retrieve current config w/o changing it */
+ u32 config = amp->gpio_config(index, ~0, 0);
+
+ /* user requested via 'v' command, so its INFO */
+ dev_info(amp->dev, "io%02u: 0x%04x %s %s %s %s %s %s %s\tio:%d/%d\n",
+ index, config,
+ (config & 1) ? "OE" : "TS", /* output-enabled/tristate */
+ (config & 2) ? "PP" : "OD", /* push pull / open drain */
+ (config & 4) ? "PUE" : "PUD", /* pull up enabled/disabled */
+ (config & 8) ? "LOCKED" : "", /* locked / unlocked */
+ (config & 16) ? "LEVEL" : "EDGE",/* level/edge input */
+ (config & 32) ? "HI" : "LO", /* trigger on rise/fall edge */
+ (config & 64) ? "DEBOUNCE" : "", /* debounce */
+
+ amp->gpio_get(index), amp->gpio_current(index));
+}
+
+ssize_t nsc_gpio_write(struct file *file, const char __user *data,
+ size_t len, loff_t *ppos)
+{
+ unsigned m = iminor(file_inode(file));
+ struct nsc_gpio_ops *amp = file->private_data;
+ struct device *dev = amp->dev;
+ size_t i;
+ int err = 0;
+
+ for (i = 0; i < len; ++i) {
+ char c;
+ if (get_user(c, data + i))
+ return -EFAULT;
+ switch (c) {
+ case '0':
+ amp->gpio_set(m, 0);
+ break;
+ case '1':
+ amp->gpio_set(m, 1);
+ break;
+ case 'O':
+ dev_dbg(dev, "GPIO%d output enabled\n", m);
+ amp->gpio_config(m, ~1, 1);
+ break;
+ case 'o':
+ dev_dbg(dev, "GPIO%d output disabled\n", m);
+ amp->gpio_config(m, ~1, 0);
+ break;
+ case 'T':
+ dev_dbg(dev, "GPIO%d output is push pull\n", m);
+ amp->gpio_config(m, ~2, 2);
+ break;
+ case 't':
+ dev_dbg(dev, "GPIO%d output is open drain\n", m);
+ amp->gpio_config(m, ~2, 0);
+ break;
+ case 'P':
+ dev_dbg(dev, "GPIO%d pull up enabled\n", m);
+ amp->gpio_config(m, ~4, 4);
+ break;
+ case 'p':
+ dev_dbg(dev, "GPIO%d pull up disabled\n", m);
+ amp->gpio_config(m, ~4, 0);
+ break;
+ case 'v':
+ /* View Current pin settings */
+ amp->gpio_dump(amp, m);
+ break;
+ case '\n':
+ /* end of settings string, do nothing */
+ break;
+ default:
+ dev_err(dev, "io%2d bad setting: chr<0x%2x>\n",
+ m, (int)c);
+ err++;
+ }
+ }
+ if (err)
+ return -EINVAL; /* full string handled, report error */
+
+ return len;
+}
+
+ssize_t nsc_gpio_read(struct file *file, char __user * buf,
+ size_t len, loff_t * ppos)
+{
+ unsigned m = iminor(file_inode(file));
+ int value;
+ struct nsc_gpio_ops *amp = file->private_data;
+
+ value = amp->gpio_get(m);
+ if (put_user(value ? '1' : '0', buf))
+ return -EFAULT;
+
+ return 1;
+}
+
+/* common file-ops routines for both scx200_gpio and pc87360_gpio */
+EXPORT_SYMBOL(nsc_gpio_write);
+EXPORT_SYMBOL(nsc_gpio_read);
+EXPORT_SYMBOL(nsc_gpio_dump);
+
+static int __init nsc_gpio_init(void)
+{
+ printk(KERN_DEBUG NAME " initializing\n");
+ return 0;
+}
+
+static void __exit nsc_gpio_cleanup(void)
+{
+ printk(KERN_DEBUG NAME " cleanup\n");
+}
+
+module_init(nsc_gpio_init);
+module_exit(nsc_gpio_cleanup);
+
+MODULE_AUTHOR("Jim Cromie <jim.cromie@gmail.com>");
+MODULE_DESCRIPTION("NatSemi GPIO Common Methods");
+MODULE_LICENSE("GPL");