[Feature]add MT2731_MP2_MR2_SVN388 baseline version
Change-Id: Ief04314834b31e27effab435d3ca8ba33b499059
diff --git a/src/kernel/linux/v4.14/drivers/hid/uhid.c b/src/kernel/linux/v4.14/drivers/hid/uhid.c
new file mode 100644
index 0000000..c749f44
--- /dev/null
+++ b/src/kernel/linux/v4.14/drivers/hid/uhid.c
@@ -0,0 +1,803 @@
+/*
+ * 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.
+ */
+
+#include <linux/atomic.h>
+#include <linux/compat.h>
+#include <linux/cred.h>
+#include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/hid.h>
+#include <linux/input.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/poll.h>
+#include <linux/sched.h>
+#include <linux/spinlock.h>
+#include <linux/uhid.h>
+#include <linux/wait.h>
+#include <linux/eventpoll.h>
+
+#define UHID_NAME "uhid"
+#define UHID_BUFSIZE 32
+
+struct uhid_device {
+ struct mutex devlock;
+ bool running;
+
+ __u8 *rd_data;
+ uint rd_size;
+
+ struct hid_device *hid;
+ struct uhid_event input_buf;
+
+ wait_queue_head_t waitq;
+ spinlock_t qlock;
+ __u8 head;
+ __u8 tail;
+ struct uhid_event *outq[UHID_BUFSIZE];
+
+ /* blocking GET_REPORT support; state changes protected by qlock */
+ struct mutex report_lock;
+ wait_queue_head_t report_wait;
+ bool report_running;
+ u32 report_id;
+ u32 report_type;
+ struct uhid_event report_buf;
+ struct work_struct worker;
+};
+
+static struct miscdevice uhid_misc;
+
+static void uhid_device_add_worker(struct work_struct *work)
+{
+ struct uhid_device *uhid = container_of(work, struct uhid_device, worker);
+ int ret;
+
+ ret = hid_add_device(uhid->hid);
+ if (ret) {
+ hid_err(uhid->hid, "Cannot register HID device: error %d\n", ret);
+
+ hid_destroy_device(uhid->hid);
+ uhid->hid = NULL;
+ uhid->running = false;
+ }
+}
+
+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_hid_start(struct hid_device *hid)
+{
+ struct uhid_device *uhid = hid->driver_data;
+ struct uhid_event *ev;
+ unsigned long flags;
+
+ ev = kzalloc(sizeof(*ev), GFP_KERNEL);
+ if (!ev)
+ return -ENOMEM;
+
+ ev->type = UHID_START;
+
+ if (hid->report_enum[HID_FEATURE_REPORT].numbered)
+ ev->u.start.dev_flags |= UHID_DEV_NUMBERED_FEATURE_REPORTS;
+ if (hid->report_enum[HID_OUTPUT_REPORT].numbered)
+ ev->u.start.dev_flags |= UHID_DEV_NUMBERED_OUTPUT_REPORTS;
+ if (hid->report_enum[HID_INPUT_REPORT].numbered)
+ ev->u.start.dev_flags |= UHID_DEV_NUMBERED_INPUT_REPORTS;
+
+ spin_lock_irqsave(&uhid->qlock, flags);
+ uhid_queue(uhid, ev);
+ spin_unlock_irqrestore(&uhid->qlock, flags);
+
+ return 0;
+}
+
+static void uhid_hid_stop(struct hid_device *hid)
+{
+ struct uhid_device *uhid = hid->driver_data;
+
+ hid->claimed = 0;
+ uhid_queue_event(uhid, UHID_STOP);
+}
+
+static int uhid_hid_open(struct hid_device *hid)
+{
+ struct uhid_device *uhid = hid->driver_data;
+
+ return uhid_queue_event(uhid, UHID_OPEN);
+}
+
+static void uhid_hid_close(struct hid_device *hid)
+{
+ struct uhid_device *uhid = hid->driver_data;
+
+ uhid_queue_event(uhid, UHID_CLOSE);
+}
+
+static int uhid_hid_parse(struct hid_device *hid)
+{
+ struct uhid_device *uhid = hid->driver_data;
+
+ return hid_parse_report(hid, uhid->rd_data, uhid->rd_size);
+}
+
+/* must be called with report_lock held */
+static int __uhid_report_queue_and_wait(struct uhid_device *uhid,
+ struct uhid_event *ev,
+ __u32 *report_id)
+{
+ unsigned long flags;
+ int ret;
+
+ spin_lock_irqsave(&uhid->qlock, flags);
+ *report_id = ++uhid->report_id;
+ uhid->report_type = ev->type + 1;
+ uhid->report_running = true;
+ uhid_queue(uhid, ev);
+ spin_unlock_irqrestore(&uhid->qlock, flags);
+
+ ret = wait_event_interruptible_timeout(uhid->report_wait,
+ !uhid->report_running || !uhid->running,
+ 5 * HZ);
+ if (!ret || !uhid->running || uhid->report_running)
+ ret = -EIO;
+ else if (ret < 0)
+ ret = -ERESTARTSYS;
+ else
+ ret = 0;
+
+ uhid->report_running = false;
+
+ return ret;
+}
+
+static void uhid_report_wake_up(struct uhid_device *uhid, u32 id,
+ const struct uhid_event *ev)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&uhid->qlock, flags);
+
+ /* id for old report; drop it silently */
+ if (uhid->report_type != ev->type || uhid->report_id != id)
+ goto unlock;
+ if (!uhid->report_running)
+ goto unlock;
+
+ memcpy(&uhid->report_buf, ev, sizeof(*ev));
+ uhid->report_running = false;
+ wake_up_interruptible(&uhid->report_wait);
+
+unlock:
+ spin_unlock_irqrestore(&uhid->qlock, flags);
+}
+
+static int uhid_hid_get_report(struct hid_device *hid, unsigned char rnum,
+ u8 *buf, size_t count, u8 rtype)
+{
+ struct uhid_device *uhid = hid->driver_data;
+ struct uhid_get_report_reply_req *req;
+ struct uhid_event *ev;
+ int ret;
+
+ if (!uhid->running)
+ return -EIO;
+
+ ev = kzalloc(sizeof(*ev), GFP_KERNEL);
+ if (!ev)
+ return -ENOMEM;
+
+ ev->type = UHID_GET_REPORT;
+ ev->u.get_report.rnum = rnum;
+ ev->u.get_report.rtype = rtype;
+
+ ret = mutex_lock_interruptible(&uhid->report_lock);
+ if (ret) {
+ kfree(ev);
+ return ret;
+ }
+
+ /* this _always_ takes ownership of @ev */
+ ret = __uhid_report_queue_and_wait(uhid, ev, &ev->u.get_report.id);
+ if (ret)
+ goto unlock;
+
+ req = &uhid->report_buf.u.get_report_reply;
+ if (req->err) {
+ ret = -EIO;
+ } else {
+ ret = min3(count, (size_t)req->size, (size_t)UHID_DATA_MAX);
+ memcpy(buf, req->data, ret);
+ }
+
+unlock:
+ mutex_unlock(&uhid->report_lock);
+ return ret;
+}
+
+static int uhid_hid_set_report(struct hid_device *hid, unsigned char rnum,
+ const u8 *buf, size_t count, u8 rtype)
+{
+ struct uhid_device *uhid = hid->driver_data;
+ struct uhid_event *ev;
+ int ret;
+
+ if (!uhid->running || count > UHID_DATA_MAX)
+ return -EIO;
+
+ ev = kzalloc(sizeof(*ev), GFP_KERNEL);
+ if (!ev)
+ return -ENOMEM;
+
+ ev->type = UHID_SET_REPORT;
+ ev->u.set_report.rnum = rnum;
+ ev->u.set_report.rtype = rtype;
+ ev->u.set_report.size = count;
+ memcpy(ev->u.set_report.data, buf, count);
+
+ ret = mutex_lock_interruptible(&uhid->report_lock);
+ if (ret) {
+ kfree(ev);
+ return ret;
+ }
+
+ /* this _always_ takes ownership of @ev */
+ ret = __uhid_report_queue_and_wait(uhid, ev, &ev->u.set_report.id);
+ if (ret)
+ goto unlock;
+
+ if (uhid->report_buf.u.set_report_reply.err)
+ ret = -EIO;
+ else
+ ret = count;
+
+unlock:
+ mutex_unlock(&uhid->report_lock);
+ return ret;
+}
+
+static int uhid_hid_raw_request(struct hid_device *hid, unsigned char reportnum,
+ __u8 *buf, size_t len, unsigned char rtype,
+ int reqtype)
+{
+ u8 u_rtype;
+
+ switch (rtype) {
+ case HID_FEATURE_REPORT:
+ u_rtype = UHID_FEATURE_REPORT;
+ break;
+ case HID_OUTPUT_REPORT:
+ u_rtype = UHID_OUTPUT_REPORT;
+ break;
+ case HID_INPUT_REPORT:
+ u_rtype = UHID_INPUT_REPORT;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ switch (reqtype) {
+ case HID_REQ_GET_REPORT:
+ return uhid_hid_get_report(hid, reportnum, buf, len, u_rtype);
+ case HID_REQ_SET_REPORT:
+ return uhid_hid_set_report(hid, reportnum, buf, len, u_rtype);
+ default:
+ return -EIO;
+ }
+}
+
+static int uhid_hid_output_raw(struct hid_device *hid, __u8 *buf, size_t count,
+ unsigned char report_type)
+{
+ struct uhid_device *uhid = hid->driver_data;
+ __u8 rtype;
+ unsigned long flags;
+ struct uhid_event *ev;
+
+ switch (report_type) {
+ case HID_FEATURE_REPORT:
+ rtype = UHID_FEATURE_REPORT;
+ break;
+ case HID_OUTPUT_REPORT:
+ rtype = UHID_OUTPUT_REPORT;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if (count < 1 || count > UHID_DATA_MAX)
+ return -EINVAL;
+
+ ev = kzalloc(sizeof(*ev), GFP_KERNEL);
+ if (!ev)
+ return -ENOMEM;
+
+ ev->type = UHID_OUTPUT;
+ ev->u.output.size = count;
+ ev->u.output.rtype = rtype;
+ memcpy(ev->u.output.data, buf, count);
+
+ spin_lock_irqsave(&uhid->qlock, flags);
+ uhid_queue(uhid, ev);
+ spin_unlock_irqrestore(&uhid->qlock, flags);
+
+ return count;
+}
+
+static int uhid_hid_output_report(struct hid_device *hid, __u8 *buf,
+ size_t count)
+{
+ return uhid_hid_output_raw(hid, buf, count, HID_OUTPUT_REPORT);
+}
+
+struct hid_ll_driver uhid_hid_driver = {
+ .start = uhid_hid_start,
+ .stop = uhid_hid_stop,
+ .open = uhid_hid_open,
+ .close = uhid_hid_close,
+ .parse = uhid_hid_parse,
+ .raw_request = uhid_hid_raw_request,
+ .output_report = uhid_hid_output_report,
+};
+EXPORT_SYMBOL_GPL(uhid_hid_driver);
+
+#ifdef CONFIG_COMPAT
+
+/* Apparently we haven't stepped on these rakes enough times yet. */
+struct uhid_create_req_compat {
+ __u8 name[128];
+ __u8 phys[64];
+ __u8 uniq[64];
+
+ compat_uptr_t rd_data;
+ __u16 rd_size;
+
+ __u16 bus;
+ __u32 vendor;
+ __u32 product;
+ __u32 version;
+ __u32 country;
+} __attribute__((__packed__));
+
+static int uhid_event_from_user(const char __user *buffer, size_t len,
+ struct uhid_event *event)
+{
+ if (in_compat_syscall()) {
+ u32 type;
+
+ if (get_user(type, buffer))
+ return -EFAULT;
+
+ if (type == UHID_CREATE) {
+ /*
+ * This is our messed up request with compat pointer.
+ * It is largish (more than 256 bytes) so we better
+ * allocate it from the heap.
+ */
+ struct uhid_create_req_compat *compat;
+
+ compat = kzalloc(sizeof(*compat), GFP_KERNEL);
+ if (!compat)
+ return -ENOMEM;
+
+ buffer += sizeof(type);
+ len -= sizeof(type);
+ if (copy_from_user(compat, buffer,
+ min(len, sizeof(*compat)))) {
+ kfree(compat);
+ return -EFAULT;
+ }
+
+ /* Shuffle the data over to proper structure */
+ event->type = type;
+
+ memcpy(event->u.create.name, compat->name,
+ sizeof(compat->name));
+ memcpy(event->u.create.phys, compat->phys,
+ sizeof(compat->phys));
+ memcpy(event->u.create.uniq, compat->uniq,
+ sizeof(compat->uniq));
+
+ event->u.create.rd_data = compat_ptr(compat->rd_data);
+ event->u.create.rd_size = compat->rd_size;
+
+ event->u.create.bus = compat->bus;
+ event->u.create.vendor = compat->vendor;
+ event->u.create.product = compat->product;
+ event->u.create.version = compat->version;
+ event->u.create.country = compat->country;
+
+ kfree(compat);
+ return 0;
+ }
+ /* All others can be copied directly */
+ }
+
+ if (copy_from_user(event, buffer, min(len, sizeof(*event))))
+ return -EFAULT;
+
+ return 0;
+}
+#else
+static int uhid_event_from_user(const char __user *buffer, size_t len,
+ struct uhid_event *event)
+{
+ if (copy_from_user(event, buffer, min(len, sizeof(*event))))
+ return -EFAULT;
+
+ return 0;
+}
+#endif
+
+static int uhid_dev_create2(struct uhid_device *uhid,
+ const struct uhid_event *ev)
+{
+ struct hid_device *hid;
+ size_t rd_size, len;
+ void *rd_data;
+ int ret;
+
+ if (uhid->running)
+ return -EALREADY;
+
+ rd_size = ev->u.create2.rd_size;
+ if (rd_size <= 0 || rd_size > HID_MAX_DESCRIPTOR_SIZE)
+ return -EINVAL;
+
+ rd_data = kmemdup(ev->u.create2.rd_data, rd_size, GFP_KERNEL);
+ if (!rd_data)
+ return -ENOMEM;
+
+ uhid->rd_size = rd_size;
+ uhid->rd_data = rd_data;
+
+ hid = hid_allocate_device();
+ if (IS_ERR(hid)) {
+ ret = PTR_ERR(hid);
+ goto err_free;
+ }
+
+ len = min(sizeof(hid->name), sizeof(ev->u.create2.name)) - 1;
+ strncpy(hid->name, ev->u.create2.name, len);
+ len = min(sizeof(hid->phys), sizeof(ev->u.create2.phys)) - 1;
+ strncpy(hid->phys, ev->u.create2.phys, len);
+ len = min(sizeof(hid->uniq), sizeof(ev->u.create2.uniq)) - 1;
+ strncpy(hid->uniq, ev->u.create2.uniq, len);
+
+ hid->ll_driver = &uhid_hid_driver;
+ hid->bus = ev->u.create2.bus;
+ hid->vendor = ev->u.create2.vendor;
+ hid->product = ev->u.create2.product;
+ hid->version = ev->u.create2.version;
+ hid->country = ev->u.create2.country;
+ hid->driver_data = uhid;
+ hid->dev.parent = uhid_misc.this_device;
+
+ uhid->hid = hid;
+ uhid->running = true;
+
+ /* Adding of a HID device is done through a worker, to allow HID drivers
+ * which use feature requests during .probe to work, without they would
+ * be blocked on devlock, which is held by uhid_char_write.
+ */
+ schedule_work(&uhid->worker);
+
+ return 0;
+
+err_free:
+ kfree(uhid->rd_data);
+ uhid->rd_data = NULL;
+ uhid->rd_size = 0;
+ return ret;
+}
+
+static int uhid_dev_create(struct uhid_device *uhid,
+ struct uhid_event *ev)
+{
+ struct uhid_create_req orig;
+
+ orig = ev->u.create;
+
+ if (orig.rd_size <= 0 || orig.rd_size > HID_MAX_DESCRIPTOR_SIZE)
+ return -EINVAL;
+ if (copy_from_user(&ev->u.create2.rd_data, orig.rd_data, orig.rd_size))
+ return -EFAULT;
+
+ memcpy(ev->u.create2.name, orig.name, sizeof(orig.name));
+ memcpy(ev->u.create2.phys, orig.phys, sizeof(orig.phys));
+ memcpy(ev->u.create2.uniq, orig.uniq, sizeof(orig.uniq));
+ ev->u.create2.rd_size = orig.rd_size;
+ ev->u.create2.bus = orig.bus;
+ ev->u.create2.vendor = orig.vendor;
+ ev->u.create2.product = orig.product;
+ ev->u.create2.version = orig.version;
+ ev->u.create2.country = orig.country;
+
+ return uhid_dev_create2(uhid, ev);
+}
+
+static int uhid_dev_destroy(struct uhid_device *uhid)
+{
+ if (!uhid->running)
+ return -EINVAL;
+
+ uhid->running = false;
+ wake_up_interruptible(&uhid->report_wait);
+
+ cancel_work_sync(&uhid->worker);
+
+ hid_destroy_device(uhid->hid);
+ kfree(uhid->rd_data);
+
+ return 0;
+}
+
+static int uhid_dev_input(struct uhid_device *uhid, struct uhid_event *ev)
+{
+ if (!uhid->running)
+ return -EINVAL;
+
+ hid_input_report(uhid->hid, HID_INPUT_REPORT, ev->u.input.data,
+ min_t(size_t, ev->u.input.size, UHID_DATA_MAX), 0);
+
+ return 0;
+}
+
+static int uhid_dev_input2(struct uhid_device *uhid, struct uhid_event *ev)
+{
+ if (!uhid->running)
+ return -EINVAL;
+
+ hid_input_report(uhid->hid, HID_INPUT_REPORT, ev->u.input2.data,
+ min_t(size_t, ev->u.input2.size, UHID_DATA_MAX), 0);
+
+ return 0;
+}
+
+static int uhid_dev_get_report_reply(struct uhid_device *uhid,
+ struct uhid_event *ev)
+{
+ if (!uhid->running)
+ return -EINVAL;
+
+ uhid_report_wake_up(uhid, ev->u.get_report_reply.id, ev);
+ return 0;
+}
+
+static int uhid_dev_set_report_reply(struct uhid_device *uhid,
+ struct uhid_event *ev)
+{
+ if (!uhid->running)
+ return -EINVAL;
+
+ uhid_report_wake_up(uhid, ev->u.set_report_reply.id, ev);
+ 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;
+
+ mutex_init(&uhid->devlock);
+ mutex_init(&uhid->report_lock);
+ spin_lock_init(&uhid->qlock);
+ init_waitqueue_head(&uhid->waitq);
+ init_waitqueue_head(&uhid->report_wait);
+ uhid->running = false;
+ INIT_WORK(&uhid->worker, uhid_device_add_worker);
+
+ 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;
+
+ uhid_dev_destroy(uhid);
+
+ for (i = 0; i < UHID_BUFSIZE; ++i)
+ kfree(uhid->outq[i]);
+
+ kfree(uhid);
+
+ return 0;
+}
+
+static ssize_t uhid_char_read(struct file *file, char __user *buffer,
+ size_t count, loff_t *ppos)
+{
+ struct uhid_device *uhid = file->private_data;
+ int ret;
+ unsigned long flags;
+ size_t len;
+
+ /* they need at least the "type" member of uhid_event */
+ if (count < sizeof(__u32))
+ return -EINVAL;
+
+try_again:
+ if (file->f_flags & O_NONBLOCK) {
+ if (uhid->head == uhid->tail)
+ return -EAGAIN;
+ } else {
+ ret = wait_event_interruptible(uhid->waitq,
+ uhid->head != uhid->tail);
+ if (ret)
+ return ret;
+ }
+
+ ret = mutex_lock_interruptible(&uhid->devlock);
+ if (ret)
+ return ret;
+
+ if (uhid->head == uhid->tail) {
+ mutex_unlock(&uhid->devlock);
+ goto try_again;
+ } else {
+ len = min(count, sizeof(**uhid->outq));
+ if (copy_to_user(buffer, uhid->outq[uhid->tail], len)) {
+ ret = -EFAULT;
+ } else {
+ kfree(uhid->outq[uhid->tail]);
+ uhid->outq[uhid->tail] = NULL;
+
+ spin_lock_irqsave(&uhid->qlock, flags);
+ uhid->tail = (uhid->tail + 1) % UHID_BUFSIZE;
+ spin_unlock_irqrestore(&uhid->qlock, flags);
+ }
+ }
+
+ mutex_unlock(&uhid->devlock);
+ return ret ? ret : len;
+}
+
+static ssize_t uhid_char_write(struct file *file, const char __user *buffer,
+ size_t count, loff_t *ppos)
+{
+ struct uhid_device *uhid = file->private_data;
+ int ret;
+ size_t len;
+
+ /* we need at least the "type" member of uhid_event */
+ if (count < sizeof(__u32))
+ return -EINVAL;
+
+ ret = mutex_lock_interruptible(&uhid->devlock);
+ if (ret)
+ return ret;
+
+ memset(&uhid->input_buf, 0, sizeof(uhid->input_buf));
+ len = min(count, sizeof(uhid->input_buf));
+
+ ret = uhid_event_from_user(buffer, len, &uhid->input_buf);
+ if (ret)
+ goto unlock;
+
+ switch (uhid->input_buf.type) {
+ case UHID_CREATE:
+ /*
+ * 'struct uhid_create_req' contains a __user pointer which is
+ * copied from, so it's unsafe to allow this with elevated
+ * privileges (e.g. from a setuid binary) or via kernel_write().
+ */
+ if (file->f_cred != current_cred() || uaccess_kernel()) {
+ pr_err_once("UHID_CREATE from different security context by process %d (%s), this is not allowed.\n",
+ task_tgid_vnr(current), current->comm);
+ ret = -EACCES;
+ goto unlock;
+ }
+ ret = uhid_dev_create(uhid, &uhid->input_buf);
+ break;
+ case UHID_CREATE2:
+ ret = uhid_dev_create2(uhid, &uhid->input_buf);
+ break;
+ case UHID_DESTROY:
+ ret = uhid_dev_destroy(uhid);
+ break;
+ case UHID_INPUT:
+ ret = uhid_dev_input(uhid, &uhid->input_buf);
+ break;
+ case UHID_INPUT2:
+ ret = uhid_dev_input2(uhid, &uhid->input_buf);
+ break;
+ case UHID_GET_REPORT_REPLY:
+ ret = uhid_dev_get_report_reply(uhid, &uhid->input_buf);
+ break;
+ case UHID_SET_REPORT_REPLY:
+ ret = uhid_dev_set_report_reply(uhid, &uhid->input_buf);
+ break;
+ default:
+ ret = -EOPNOTSUPP;
+ }
+
+unlock:
+ mutex_unlock(&uhid->devlock);
+
+ /* return "count" not "len" to not confuse the caller */
+ return ret ? ret : count;
+}
+
+static unsigned int uhid_char_poll(struct file *file, poll_table *wait)
+{
+ struct uhid_device *uhid = file->private_data;
+ unsigned int mask = POLLOUT | POLLWRNORM; /* uhid is always writable */
+
+ poll_wait(file, &uhid->waitq, wait);
+
+ if (uhid->head != uhid->tail)
+ mask |= POLLIN | POLLRDNORM;
+
+ return mask;
+}
+
+static const struct file_operations uhid_fops = {
+ .owner = THIS_MODULE,
+ .open = uhid_char_open,
+ .release = uhid_char_release,
+ .read = uhid_char_read,
+ .write = uhid_char_write,
+ .poll = uhid_char_poll,
+ .llseek = no_llseek,
+};
+
+static struct miscdevice uhid_misc = {
+ .fops = &uhid_fops,
+ .minor = UHID_MINOR,
+ .name = UHID_NAME,
+};
+module_misc_device(uhid_misc);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("David Herrmann <dh.herrmann@gmail.com>");
+MODULE_DESCRIPTION("User-space I/O driver support for HID subsystem");
+MODULE_ALIAS_MISCDEV(UHID_MINOR);
+MODULE_ALIAS("devname:" UHID_NAME);