HID: roccat: Add ioctl command to retreive report size from chardev

Roccat chardev was reworked to support only a defined report size per
device and this can be retreived by an ioctl now to enable future changes
in report definitions.
Header was moved/renamed from drivers/hid to include/linux for accessibility.

Signed-off-by: Stefan Achatz <erazor_de@users.sourceforge.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

1 files changed, 38 insertions, 10 deletions

diff --git a/drivers/hid/hid-roccat.c b/drivers/hid/hid-roccat.c
index a14c579ea781..0fa23dead5e1 100644
--- a/drivers/hid/hid-roccat.c
+++ b/drivers/hid/hid-roccat.c
@@ -26,8 +26,7 @@
 #include <linux/cdev.h>
 #include <linux/poll.h>
 #include <linux/sched.h>
-
-#include "hid-roccat.h"
+#include <linux/roccat.h>
 
 #define ROCCAT_FIRST_MINOR 0
 #define ROCCAT_MAX_DEVICES 8
@@ -37,11 +36,11 @@
 
 struct roccat_report {
         uint8_t *value;
-        int len;
 };
 
 struct roccat_device {
         unsigned int minor;
+        int report_size;
         int open;
         int exist;
         wait_queue_head_t wait;
@@ -123,7 +122,7 @@ static ssize_t roccat_read(struct file *file, char __user *buffer,
          * If report is larger than requested amount of data, rest of report
          * is lost!
          */
-        len = report->len > count ? count : report->len;
+        len = device->report_size > count ? count : device->report_size;
 
         if (copy_to_user(buffer, report->value, len)) {
                 retval = -EFAULT;
@@ -248,26 +247,25 @@ static int roccat_release(struct inode *inode, struct file *file)
  *
  * This is called from interrupt handler.
  */
-int roccat_report_event(int minor, u8 const *data, int len)
+int roccat_report_event(int minor, u8 const *data)
 {
         struct roccat_device *device;
         struct roccat_reader *reader;
         struct roccat_report *report;
         uint8_t *new_value;
 
-        new_value = kmemdup(data, len, GFP_ATOMIC);
+        device = devices[minor];
+
+        new_value = kmemdup(data, device->report_size, GFP_ATOMIC);
         if (!new_value)
                 return -ENOMEM;
 
-        device = devices[minor];
-
         report = &device->cbuf[device->cbuf_end];
 
         /* passing NULL is safe */
         kfree(report->value);
 
         report->value = new_value;
-        report->len = len;
         device->cbuf_end = (device->cbuf_end + 1) % ROCCAT_CBUF_SIZE;
 
         list_for_each_entry(reader, &device->readers, node) {
@@ -295,7 +293,7 @@ EXPORT_SYMBOL_GPL(roccat_report_event);
  * Return value is minor device number in Range [0, ROCCAT_MAX_DEVICES] on
  * success, a negative error code on failure.
  */
-int roccat_connect(struct class *klass, struct hid_device *hid)
+int roccat_connect(struct class *klass, struct hid_device *hid, int report_size)
 {
         unsigned int minor;
         struct roccat_device *device;
@@ -343,6 +341,7 @@ int roccat_connect(struct class *klass, struct hid_device *hid)
         device->hid = hid;
         device->exist = 1;
         device->cbuf_end = 0;
+        device->report_size = report_size;
 
         return minor;
 }
@@ -373,6 +372,34 @@ void roccat_disconnect(int minor)
 }
 EXPORT_SYMBOL_GPL(roccat_disconnect);
 
+static long roccat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+        struct inode *inode = file->f_path.dentry->d_inode;
+        struct roccat_device *device;
+        unsigned int minor = iminor(inode);
+        long retval = 0;
+
+        mutex_lock(&devices_lock);
+
+        device = devices[minor];
+        if (!device) {
+                retval = -ENODEV;
+                goto out;
+        }
+
+        switch (cmd) {
+        case ROCCATIOCGREPSIZE:
+                if (put_user(device->report_size, (int __user *)arg))
+                        retval = -EFAULT;
+                break;
+        default:
+                retval = -ENOTTY;
+        }
+out:
+        mutex_unlock(&devices_lock);
+        return retval;
+}
+
 static const struct file_operations roccat_ops = {
         .owner = THIS_MODULE,
         .read = roccat_read,
@@ -380,6 +407,7 @@ static const struct file_operations roccat_ops = {
         .open = roccat_open,
         .release = roccat_release,
         .llseek = noop_llseek,
+        .unlocked_ioctl = roccat_ioctl,
 };
 
 static int __init roccat_init(void)