HID: detect Win 8 multitouch devices in core

Detecting Win 8 multitouch devices in core allows us to set quirks
before the device is parsed through hid_hw_start().
It also simplifies the detection of those devices in hid-multitouch and
makes the handling of those devices cleaner.

As Win 8 multitouch panels are in the group multitouch and rely on a
special feature to be detected, this patch adds a bitfield in the parser.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Reviewed-by: Henrik Rydberg <rydberg@euromail.se>
Tested-by: Srinivas Pandruvada<srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

3 files changed, 31 insertions, 13 deletions

diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index ddd95f3e33c0..660dce964162 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -685,6 +685,13 @@ static void hid_scan_input_usage(struct hid_parser *parser, u32 usage)
                 hid->group = HID_GROUP_MULTITOUCH;
 }
 
+static void hid_scan_feature_usage(struct hid_parser *parser, u32 usage)
+{
+        if (usage == 0xff0000c5 && parser->global.report_count == 256 &&
+            parser->global.report_size == 8)
+                parser->scan_flags |= HID_SCAN_FLAG_MT_WIN_8;
+}
+
 static void hid_scan_collection(struct hid_parser *parser, unsigned type)
 {
         struct hid_device *hid = parser->device;
@@ -714,6 +721,8 @@ static int hid_scan_main(struct hid_parser *parser, struct hid_item *item)
         case HID_MAIN_ITEM_TAG_OUTPUT:
                 break;
         case HID_MAIN_ITEM_TAG_FEATURE:
+                for (i = 0; i < parser->local.usage_index; i++)
+                        hid_scan_feature_usage(parser, parser->local.usage[i]);
                 break;
         }
 
@@ -757,6 +766,13 @@ static int hid_scan_report(struct hid_device *hid)
         while ((start = fetch_item(start, end, &item)) != NULL)
                 dispatch_type[item.type](parser, &item);
 
+        /*
+         * Handle special flags set during scanning.
+         */
+        if ((parser->scan_flags & HID_SCAN_FLAG_MT_WIN_8) &&
+            (hid->group == HID_GROUP_MULTITOUCH))
+                hid->group = HID_GROUP_MULTITOUCH_WIN_8;
+
         vfree(parser);
         return 0;
 }
diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
index 0fe00e2552f2..c28ef86c7c67 100644
--- a/drivers/hid/hid-multitouch.c
+++ b/drivers/hid/hid-multitouch.c
@@ -133,6 +133,7 @@ static void mt_post_parse(struct mt_device *td);
 #define MT_CLS_NSMU                             0x000a
 #define MT_CLS_DUAL_CONTACT_NUMBER              0x0010
 #define MT_CLS_DUAL_CONTACT_ID                  0x0011
+#define MT_CLS_WIN_8                            0x0012
 
 /* vendor specific classes */
 #define MT_CLS_3M                               0x0101
@@ -205,6 +206,11 @@ static struct mt_class mt_classes[] = {
                         MT_QUIRK_CONTACT_CNT_ACCURATE |
                         MT_QUIRK_SLOT_IS_CONTACTID,
                 .maxcontacts = 2 },
+        { .name = MT_CLS_WIN_8,
+                .quirks = MT_QUIRK_ALWAYS_VALID |
+                        MT_QUIRK_IGNORE_DUPLICATES |
+                        MT_QUIRK_HOVERING |
+                        MT_QUIRK_CONTACT_CNT_ACCURATE },
 
         /*
          * vendor specific classes
@@ -332,19 +338,6 @@ static void mt_feature_mapping(struct hid_device *hdev,
                         td->maxcontacts = td->mtclass.maxcontacts;
 
                 break;
-        case 0xff0000c5:
-                if (field->report_count == 256 && field->report_size == 8) {
-                        /* Win 8 devices need special quirks */
-                        __s32 *quirks = &td->mtclass.quirks;
-                        *quirks |= MT_QUIRK_ALWAYS_VALID;
-                        *quirks |= MT_QUIRK_IGNORE_DUPLICATES;
-                        *quirks |= MT_QUIRK_HOVERING;
-                        *quirks |= MT_QUIRK_CONTACT_CNT_ACCURATE;
-                        *quirks &= ~MT_QUIRK_NOT_SEEN_MEANS_UP;
-                        *quirks &= ~MT_QUIRK_VALID_IS_INRANGE;
-                        *quirks &= ~MT_QUIRK_VALID_IS_CONFIDENCE;
-                }
-                break;
         }
 }
 
@@ -1346,6 +1339,11 @@ static const struct hid_device_id mt_devices[] = {
 
         /* Generic MT device */
         { HID_DEVICE(HID_BUS_ANY, HID_GROUP_MULTITOUCH, HID_ANY_ID, HID_ANY_ID) },
+
+        /* Generic Win 8 certified MT device */
+        {  .driver_data = MT_CLS_WIN_8,
+                HID_DEVICE(HID_BUS_ANY, HID_GROUP_MULTITOUCH_WIN_8,
+                        HID_ANY_ID, HID_ANY_ID) },
         { }
 };
 MODULE_DEVICE_TABLE(hid, mt_devices);
diff --git a/include/linux/hid.h b/include/linux/hid.h
index 0c48991b0402..cef1e9b86cc4 100644
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -295,6 +295,7 @@ struct hid_item {
 #define HID_GROUP_GENERIC                       0x0001
 #define HID_GROUP_MULTITOUCH                    0x0002
 #define HID_GROUP_SENSOR_HUB                    0x0003
+#define HID_GROUP_MULTITOUCH_WIN_8              0x0004
 
 /*
  * This is the global environment of the parser. This information is
@@ -532,6 +533,8 @@ static inline void hid_set_drvdata(struct hid_device *hdev, void *data)
 #define HID_GLOBAL_STACK_SIZE 4
 #define HID_COLLECTION_STACK_SIZE 4
 
+#define HID_SCAN_FLAG_MT_WIN_8                  0x00000001
+
 struct hid_parser {
         struct hid_global     global;
         struct hid_global     global_stack[HID_GLOBAL_STACK_SIZE];
@@ -540,6 +543,7 @@ struct hid_parser {
         unsigned              collection_stack[HID_COLLECTION_STACK_SIZE];
         unsigned              collection_stack_ptr;
         struct hid_device    *device;
+        unsigned              scan_flags;
 };
 
 struct hid_class_descriptor {