patch-2.4.21 linux-2.4.21/drivers/char/scx200_gpio.c

• Lines: 155
• Date: 2003-06-13 07:51:33.000000000 -0700
• Orig file: linux-2.4.20/drivers/char/scx200_gpio.c
• Orig date: 1969-12-31 16:00:00.000000000 -0800

diff -urN linux-2.4.20/drivers/char/scx200_gpio.c linux-2.4.21/drivers/char/scx200_gpio.c
@@ -0,0 +1,154 @@
+/* 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/config.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <asm/uaccess.h>
+#include <asm/io.h>
+
+#include <linux/scx200_gpio.h>
+
+#define NAME "scx200_gpio"
+
+MODULE_AUTHOR("Christer Weinigel <wingel@nano-system.com>");
+MODULE_DESCRIPTION("NatSemi SCx200 GPIO Pin Driver");
+MODULE_LICENSE("GPL");
+
+static int major = 0;		/* default to dynamic major */
+MODULE_PARM(major, "i");
+MODULE_PARM_DESC(major, "Major device number");
+
+static ssize_t scx200_gpio_write(struct file *file, const char *data, 
+				 size_t len, loff_t *ppos)
+{
+	unsigned m = minor(file->f_dentry->d_inode->i_rdev);
+	size_t i;
+
+	if (ppos != &file->f_pos)
+		return -ESPIPE;
+
+	for (i = 0; i < len; ++i) {
+		char c;
+		if (get_user(c, data+i))
+			return -EFAULT;
+		switch (c)
+		{
+		case '0': 
+			scx200_gpio_set(m, 0); 
+			break;
+		case '1': 
+			scx200_gpio_set(m, 1); 
+			break;
+		case 'O':
+			printk(KERN_INFO NAME ": GPIO%d output enabled\n", m);
+			scx200_gpio_configure(m, ~1, 1);
+			break;
+		case 'o':
+			printk(KERN_INFO NAME ": GPIO%d output disabled\n", m);
+			scx200_gpio_configure(m, ~1, 0);
+			break;
+		case 'T':
+			printk(KERN_INFO NAME ": GPIO%d output is push pull\n", m);
+			scx200_gpio_configure(m, ~2, 2);
+			break;
+		case 't':
+			printk(KERN_INFO NAME ": GPIO%d output is open drain\n", m);
+			scx200_gpio_configure(m, ~2, 0);
+			break;
+		case 'P':
+			printk(KERN_INFO NAME ": GPIO%d pull up enabled\n", m);
+			scx200_gpio_configure(m, ~4, 4);
+			break;
+		case 'p':
+			printk(KERN_INFO NAME ": GPIO%d pull up disabled\n", m);
+			scx200_gpio_configure(m, ~4, 0);
+			break;
+		}
+	}
+
+	return len;
+}
+
+static ssize_t scx200_gpio_read(struct file *file, char *buf,
+				size_t len, loff_t *ppos)
+{
+	unsigned m = minor(file->f_dentry->d_inode->i_rdev);
+	int value;
+
+	if (ppos != &file->f_pos)
+		return -ESPIPE;
+
+	value = scx200_gpio_get(m);
+	if (put_user(value ? '1' : '0', buf))
+		return -EFAULT;
+	
+	return 1;
+}
+
+static int scx200_gpio_open(struct inode *inode, struct file *file)
+{
+	unsigned m = minor(inode->i_rdev);
+	if (m > 63)
+		return -EINVAL;
+	return 0;
+}
+
+static int scx200_gpio_release(struct inode *inode, struct file *file)
+{
+	return 0;
+}
+
+
+static struct file_operations scx200_gpio_fops = {
+	.owner   = THIS_MODULE,
+	.write   = scx200_gpio_write,
+	.read    = scx200_gpio_read,
+	.open    = scx200_gpio_open,
+	.release = scx200_gpio_release,
+};
+
+static int __init scx200_gpio_init(void)
+{
+	int r;
+
+	printk(KERN_DEBUG NAME ": NatSemi SCx200 GPIO Driver\n");
+
+	if (!scx200_gpio_present()) {
+		printk(KERN_ERR NAME ": no SCx200 gpio pins available\n");
+		return -ENODEV;
+	}
+
+	r = register_chrdev(major, NAME, &scx200_gpio_fops);
+	if (r < 0) {
+		printk(KERN_ERR NAME ": unable to register character device\n");
+		return r;
+	}
+	if (!major) {
+		major = r;
+		printk(KERN_DEBUG NAME ": got dynamic major %d\n", major);
+	}
+
+	return 0;
+}
+
+static void __exit scx200_gpio_cleanup(void)
+{
+	unregister_chrdev(major, NAME);
+}
+
+module_init(scx200_gpio_init);
+module_exit(scx200_gpio_cleanup);
+
+/*
+    Local variables:
+        compile-command: "make -k -C ../.. SUBDIRS=drivers/char modules"
+        c-basic-offset: 8
+    End:
+*/