diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/char/scx200_gpio.c |
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.c | 149 |
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: +*/ |