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authorblogic <blogic@3c298f89-4303-0410-b956-a3cf2f4a3e73>2012-10-05 10:12:53 +0000
committerblogic <blogic@3c298f89-4303-0410-b956-a3cf2f4a3e73>2012-10-05 10:12:53 +0000
commit5c105d9f3fd086aff195d3849dcf847d6b0bd927 (patch)
tree1229a11f725bfa58aa7c57a76898553bb5f6654a /target/linux/generic/files/drivers/char
downloadopenwrt-5c105d9f3fd086aff195d3849dcf847d6b0bd927.tar.gz
openwrt-5c105d9f3fd086aff195d3849dcf847d6b0bd927.zip
branch Attitude Adjustment
git-svn-id: svn://svn.openwrt.org/openwrt/branches/attitude_adjustment@33625 3c298f89-4303-0410-b956-a3cf2f4a3e73
Diffstat (limited to 'target/linux/generic/files/drivers/char')
-rw-r--r--target/linux/generic/files/drivers/char/gpio_dev.c181
1 files changed, 181 insertions, 0 deletions
diff --git a/target/linux/generic/files/drivers/char/gpio_dev.c b/target/linux/generic/files/drivers/char/gpio_dev.c
new file mode 100644
index 000000000..c74157302
--- /dev/null
+++ b/target/linux/generic/files/drivers/char/gpio_dev.c
@@ -0,0 +1,181 @@
+/*
+ * character device wrapper for generic gpio layer
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA02111-1307USA
+ *
+ * Feedback, Bugs... blogic@openwrt.org
+ *
+ * dpg 20100106
+ */
+
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <asm/uaccess.h>
+#include <asm/io.h>
+#include <asm/gpio.h>
+#include <asm/atomic.h>
+#include <linux/init.h>
+#include <linux/genhd.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/gpio_dev.h>
+#include <linux/fs.h>
+
+#define DRVNAME "gpiodev"
+#define DEVNAME "gpio"
+
+static int dev_major;
+static struct class *gpiodev_class;
+
+
+/* third argument of user space ioctl ('arg' here) contains the <pin> */
+static int
+gpio_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+ int retval = 0;
+
+ switch (cmd)
+ {
+ case GPIO_GET:
+ retval = gpio_get_value(arg);
+ break;
+ case GPIO_SET:
+ gpio_set_value(arg, 1);
+ break;
+ case GPIO_CLEAR:
+ gpio_set_value(arg, 0);
+ break;
+ case GPIO_DIR_IN:
+ retval = gpio_direction_input(arg);
+ break;
+ case GPIO_DIR_OUT:
+ retval = gpio_direction_output(arg, 0);
+ break;
+ case GPIO_DIR_HIGH:
+ retval = gpio_direction_output(arg, 1);
+ break;
+ case GPIO_REQUEST:
+ /* should be first ioctl operation on <pin> */
+ retval = gpio_request(arg, DRVNAME);
+ break;
+ case GPIO_FREE:
+ /* should be last ioctl operation on <pin> */
+ /* may be needed first if previous user missed this ioctl */
+ gpio_free(arg);
+ break;
+ case GPIO_CAN_SLEEP:
+ retval = gpio_cansleep(arg);
+ break;
+ default:
+ retval = -EINVAL;
+ /* = -ENOTTY; // correct return but ... */
+ break;
+ }
+ return retval;
+}
+
+/* Allow co-incident opens */
+static int
+gpio_open(struct inode *inode, struct file *file)
+{
+ int result = 0;
+ unsigned int dev_minor = MINOR(inode->i_rdev);
+
+ if (dev_minor != 0)
+ {
+ printk(KERN_ERR DRVNAME ": trying to access unknown minor device -> %d\n", dev_minor);
+ result = -ENODEV;
+ goto out;
+ }
+out:
+ return result;
+}
+
+static int
+gpio_close(struct inode * inode, struct file * file)
+{
+ /* could track all <pin>s requested by this fd and gpio_free()
+ * them here
+ */
+ return 0;
+}
+
+struct file_operations gpio_fops = {
+ unlocked_ioctl: gpio_ioctl,
+ open: gpio_open,
+ release: gpio_close
+};
+
+static int
+gpio_probe(struct platform_device *dev)
+{
+ int result = 0;
+
+ dev_major = register_chrdev(0, DEVNAME, &gpio_fops);
+ if (!dev_major)
+ {
+ printk(KERN_ERR DRVNAME ": Error whilst opening %s \n", DEVNAME);
+ result = -ENODEV;
+ goto out;
+ }
+ gpiodev_class = class_create(THIS_MODULE, DRVNAME);
+ device_create(gpiodev_class, NULL, MKDEV(dev_major, 0), dev, DEVNAME);
+ printk(KERN_INFO DRVNAME ": gpio device registered with major %d\n", dev_major);
+out:
+ return result;
+}
+
+static int
+gpio_remove(struct platform_device *dev)
+{
+ device_destroy(gpiodev_class, MKDEV(dev_major, 0));
+ class_destroy(gpiodev_class);
+ unregister_chrdev(dev_major, DEVNAME);
+ return 0;
+}
+
+static struct
+platform_driver gpio_driver = {
+ .probe = gpio_probe,
+ .remove = gpio_remove,
+ .driver = {
+ .name = "GPIODEV",
+ .owner = THIS_MODULE,
+ },
+};
+
+static int __init
+gpio_mod_init(void)
+{
+ int ret = platform_driver_register(&gpio_driver);
+ if (ret)
+ printk(KERN_INFO DRVNAME ": Error registering platfom driver!\n");
+
+ return ret;
+}
+
+static void __exit
+gpio_mod_exit(void)
+{
+ platform_driver_unregister(&gpio_driver);
+}
+
+module_init (gpio_mod_init);
+module_exit (gpio_mod_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("John Crispin / OpenWrt +");
+MODULE_DESCRIPTION("Character device for for generic gpio api");