HID: Add Support for Setting and Getting Feature Reports from hidraw

Per the HID Specification, Feature reports must be sent and received on
the Configuration endpoint (EP 0) through the Set_Report/Get_Report
interfaces.  This patch adds two ioctls to hidraw to set and get feature
reports to and from the device.  Modifications were made to hidraw and
usbhid.

New hidraw ioctls:
  HIDIOCSFEATURE - Perform a Set_Report transfer of a Feature report.
  HIDIOCGFEATURE - Perform a Get_Report transfer of a Feature report.

Signed-off-by: Alan Ott <alan@signal11.us>
Signed-off-by: Antonio Ospite <ospite@studenti.unina.it>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

1 files changed, 35 insertions, 0 deletions

diff --git a/drivers/hid/usbhid/hid-core.c b/drivers/hid/usbhid/hid-core.c
index b336dd84036f..38c261a40c74 100644
--- a/drivers/hid/usbhid/hid-core.c
+++ b/drivers/hid/usbhid/hid-core.c
@@ -799,6 +799,40 @@ static int hid_alloc_buffers(struct usb_device *dev, struct hid_device *hid)
         return 0;
 }
 
+static int usbhid_get_raw_report(struct hid_device *hid,
+                unsigned char report_number, __u8 *buf, size_t count,
+                unsigned char report_type)
+{
+        struct usbhid_device *usbhid = hid->driver_data;
+        struct usb_device *dev = hid_to_usb_dev(hid);
+        struct usb_interface *intf = usbhid->intf;
+        struct usb_host_interface *interface = intf->cur_altsetting;
+        int skipped_report_id = 0;
+        int ret;
+
+        /* Byte 0 is the report number. Report data starts at byte 1.*/
+        buf[0] = report_number;
+        if (report_number == 0x0) {
+                /* Offset the return buffer by 1, so that the report ID
+                   will remain in byte 0. */
+                buf++;
+                count--;
+                skipped_report_id = 1;
+        }
+        ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
+                HID_REQ_GET_REPORT,
+                USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
+                ((report_type + 1) << 8) | report_number,
+                interface->desc.bInterfaceNumber, buf, count,
+                USB_CTRL_SET_TIMEOUT);
+
+        /* count also the report id */
+        if (ret > 0 && skipped_report_id)
+                ret++;
+
+        return ret;
+}
+
 static int usbhid_output_raw_report(struct hid_device *hid, __u8 *buf, size_t count,
                 unsigned char report_type)
 {
@@ -1139,6 +1173,7 @@ static int usbhid_probe(struct usb_interface *intf, const struct usb_device_id *
 
         usb_set_intfdata(intf, hid);
         hid->ll_driver = &usb_hid_driver;
+        hid->hid_get_raw_report = usbhid_get_raw_report;
         hid->hid_output_raw_report = usbhid_output_raw_report;
         hid->ff_init = hid_pidff_init;
 #ifdef CONFIG_USB_HIDDEV