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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/char/scx200_gpio.c
downloadlinux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'drivers/char/scx200_gpio.c')
-rw-r--r--drivers/char/scx200_gpio.c149
1 files changed, 149 insertions, 0 deletions
diff --git a/drivers/char/scx200_gpio.c b/drivers/char/scx200_gpio.c
new file mode 100644
index 00000000000..664a6e97eb1
--- /dev/null
+++ b/drivers/char/scx200_gpio.c
@@ -0,0 +1,149 @@
+/* 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/fs.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_param(major, int, 0);
+MODULE_PARM_DESC(major, "Major device number");
+
+static ssize_t scx200_gpio_write(struct file *file, const char __user *data,
+ size_t len, loff_t *ppos)
+{
+ unsigned m = iminor(file->f_dentry->d_inode);
+ size_t i;
+
+ 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 __user *buf,
+ size_t len, loff_t *ppos)
+{
+ unsigned m = iminor(file->f_dentry->d_inode);
+ int value;
+
+ 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 = iminor(inode);
+ if (m > 63)
+ return -EINVAL;
+ return nonseekable_open(inode, file);
+}
+
+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:
+*/