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>

1 files changed, 10 insertions, 60 deletions

diff --git a/drivers/input/tablet/wacom_sys.c b/drivers/input/tablet/wacom_sys.c
index 120ab1b5df3c..2c0983bd0504 100644
--- 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");