diff options
| -rw-r--r-- | drivers/hid/uhid.c | 65 | ||||
| -rw-r--r-- | include/linux/Kbuild | 1 | ||||
| -rw-r--r-- | include/linux/uhid.h | 33 |
3 files changed, 99 insertions, 0 deletions
diff --git a/drivers/hid/uhid.c b/drivers/hid/uhid.c index 5b02d6cb0e60..05ef4b05a63e 100644 --- a/drivers/hid/uhid.c +++ b/drivers/hid/uhid.c @@ -25,16 +25,81 @@ #include <linux/wait.h> #define UHID_NAME "uhid" +#define UHID_BUFSIZE 32 + +struct uhid_device { + struct hid_device *hid; + + wait_queue_head_t waitq; + spinlock_t qlock; + __u8 head; + __u8 tail; + struct uhid_event *outq[UHID_BUFSIZE]; +}; static struct miscdevice uhid_misc; +static void uhid_queue(struct uhid_device *uhid, struct uhid_event *ev) +{ + __u8 newhead; + + newhead = (uhid->head + 1) % UHID_BUFSIZE; + + if (newhead != uhid->tail) { + uhid->outq[uhid->head] = ev; + uhid->head = newhead; + wake_up_interruptible(&uhid->waitq); + } else { + hid_warn(uhid->hid, "Output queue is full\n"); + kfree(ev); + } +} + +static int uhid_queue_event(struct uhid_device *uhid, __u32 event) +{ + unsigned long flags; + struct uhid_event *ev; + + ev = kzalloc(sizeof(*ev), GFP_KERNEL); + if (!ev) + return -ENOMEM; + + ev->type = event; + + spin_lock_irqsave(&uhid->qlock, flags); + uhid_queue(uhid, ev); + spin_unlock_irqrestore(&uhid->qlock, flags); + + return 0; +} + static int uhid_char_open(struct inode *inode, struct file *file) { + struct uhid_device *uhid; + + uhid = kzalloc(sizeof(*uhid), GFP_KERNEL); + if (!uhid) + return -ENOMEM; + + spin_lock_init(&uhid->qlock); + init_waitqueue_head(&uhid->waitq); + + file->private_data = uhid; + nonseekable_open(inode, file); + return 0; } static int uhid_char_release(struct inode *inode, struct file *file) { + struct uhid_device *uhid = file->private_data; + unsigned int i; + + for (i = 0; i < UHID_BUFSIZE; ++i) + kfree(uhid->outq[i]); + + kfree(uhid); + return 0; } diff --git a/include/linux/Kbuild b/include/linux/Kbuild index 39737839ce29..8cdabecfbe27 100644 --- a/include/linux/Kbuild +++ b/include/linux/Kbuild @@ -373,6 +373,7 @@ header-y += tty.h header-y += types.h header-y += udf_fs_i.h header-y += udp.h +header-y += uhid.h header-y += uinput.h header-y += uio.h header-y += ultrasound.h diff --git a/include/linux/uhid.h b/include/linux/uhid.h new file mode 100644 index 000000000000..16b786a2b18f --- /dev/null +++ b/include/linux/uhid.h @@ -0,0 +1,33 @@ +#ifndef __UHID_H_ +#define __UHID_H_ + +/* + * User-space I/O driver support for HID subsystem + * Copyright (c) 2012 David Herrmann + */ + +/* + * 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. + */ + +/* + * Public header for user-space communication. We try to keep every structure + * aligned but to be safe we also use __attribute__((__packed__)). Therefore, + * the communication should be ABI compatible even between architectures. + */ + +#include <linux/input.h> +#include <linux/types.h> + +enum uhid_event_type { + UHID_DUMMY, +}; + +struct uhid_event { + __u32 type; +} __attribute__((__packed__)); + +#endif /* __UHID_H_ */ |