Input: wacom - use HID core to actually fetch the report descriptor

HID core already retrieves the report descritor. There is no need
to ask ourself for one.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Reviewed-by: Jason Gerecke <killertofu@gmail.com>
Tested-by: Jason Gerecke <killertofu@gmail.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

diff --git a/drivers/input/tablet/wacom_sys.c b/drivers/input/tablet/wacom_sys.c
index 120ab1b..2c0983b 100644 (file)
--- a/drivers/input/tablet/wacom_sys.c
+++ b/drivers/input/tablet/wacom_sys.c
@@ -15,9 +15,6 @@
 #include "wacom.h"
 #include <linux/hid.h>
 
-/* defines to get HID report descriptor */
-#define HID_DEVICET_HID                (USB_TYPE_CLASS | 0x01)
-#define HID_DEVICET_REPORT     (USB_TYPE_CLASS | 0x02)
 #define HID_HDESC_USAGE_UNDEFINED      0x00
 #define HID_HDESC_USAGE_PAGE           0x05
 #define HID_HDESC_USAGE                        0x09
@@ -25,15 +22,6 @@
 #define HID_HDESC_COLLECTION_LOGICAL   0x02
 #define HID_HDESC_COLLECTION_END       0xc0
 
-struct wac_hid_descriptor {
-       struct usb_descriptor_header header;
-       __le16   bcdHID;
-       u8       bCountryCode;
-       u8       bNumDescriptors;
-       u8       bDescriptorType;
-       __le16   wDescriptorLength;
-} __attribute__ ((packed));
-
 #define WAC_MSG_RETRIES                5
 
 #define WAC_CMD_LED_CONTROL    0x20
@@ -230,39 +218,14 @@ static void wacom_retrieve_report_data(struct hid_device *hdev,
  * this after returning from this function.
  */
 static int wacom_parse_hid(struct hid_device *hdev,
-                          struct wac_hid_descriptor *hid_desc,
                           struct wacom_features *features)
 {
-       struct wacom *wacom = hid_get_drvdata(hdev);
-       struct usb_interface *intf = wacom->intf;
-       struct usb_device *dev = interface_to_usbdev(intf);
-       char limit = 0;
        /* result has to be defined as int for some devices */
        int result = 0, touch_max = 0;
        int i = 0, page = 0, finger = 0, pen = 0;
-       unsigned char *report;
+       unsigned char *report = hdev->rdesc;
 
-       report = kzalloc(hid_desc->wDescriptorLength, GFP_KERNEL);
-       if (!report)
-               return -ENOMEM;
-
-       /* retrive report descriptors */
-       do {
-               result = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
-                       USB_REQ_GET_DESCRIPTOR,
-                       USB_RECIP_INTERFACE | USB_DIR_IN,
-                       HID_DEVICET_REPORT << 8,
-                       intf->altsetting[0].desc.bInterfaceNumber, /* interface */
-                       report,
-                       hid_desc->wDescriptorLength,
-                       5000); /* 5 secs */
-       } while (result < 0 && limit++ < WAC_MSG_RETRIES);
-
-       /* No need to parse the Descriptor. It isn't an error though */
-       if (result < 0)
-               goto out;
-
-       for (i = 0; i < hid_desc->wDescriptorLength; i++) {
+       for (i = 0; i < hdev->rsize; i++) {
 
                switch (report[i]) {
                case HID_HDESC_USAGE_PAGE:
@@ -452,11 +415,9 @@ static int wacom_parse_hid(struct hid_device *hdev,
                }
        }
 
- out:
        if (!features->touch_max && touch_max)
                features->touch_max = touch_max;
        result = 0;
-       kfree(report);
        return result;
 }
 
@@ -519,8 +480,6 @@ static int wacom_retrieve_hid_descriptor(struct hid_device *hdev,
        int error = 0;
        struct wacom *wacom = hid_get_drvdata(hdev);
        struct usb_interface *intf = wacom->intf;
-       struct usb_host_interface *interface = intf->cur_altsetting;
-       struct wac_hid_descriptor *hid_desc;
 
        /* default features */
        features->device_type = BTN_TOOL_PEN;
@@ -549,17 +508,7 @@ static int wacom_retrieve_hid_descriptor(struct hid_device *hdev,
                goto out;
        }
 
-       error = usb_get_extra_descriptor(interface, HID_DEVICET_HID, &hid_desc);
-       if (error) {
-               error = usb_get_extra_descriptor(&interface->endpoint[0],
-                                                HID_DEVICET_REPORT, &hid_desc);
-               if (error) {
-                       hid_err(hdev,
-                               "can not retrieve extra class descriptor\n");
-                       goto out;
-               }
-       }
-       error = wacom_parse_hid(hdev, hid_desc, features);
+       error = wacom_parse_hid(hdev, features);
 
  out:
        return error;
@@ -1296,6 +1245,13 @@ static int wacom_probe(struct hid_device *hdev,
        hid_set_drvdata(hdev, wacom);
        wacom->hdev = hdev;
 
+       /* ask for the report descriptor to be loaded by HID */
+       error = hid_parse(hdev);
+       if (error) {
+               hid_err(hdev, "parse failed\n");
+               goto fail1;
+       }
+
        wacom_wac = &wacom->wacom_wac;
        wacom_wac->features = *((struct wacom_features *)id->driver_data);
        features = &wacom_wac->features;
@@ -1389,12 +1345,6 @@ static int wacom_probe(struct hid_device *hdev,
        wacom_query_tablet_data(hdev, features);
 
        /* Regular HID work starts now */
-       error = hid_parse(hdev);
-       if (error) {
-               hid_err(hdev, "parse failed\n");
-               goto fail4;
-       }
-
        error = hid_hw_start(hdev, HID_CONNECT_HIDRAW);
        if (error) {
                hid_err(hdev, "hw start failed\n");