HID: wacom: store the hid_device pointers of the sibling devices

The Bamboo PAD in debug mode needs to re-route events from the debug
interface to the Pen interface. This can be easily done with
hid_input_report(), but that means that we need to keep a reference to
the various hid_devices.

There should be only one touch and one pen interface per physical tablet,
so there is no need to keep a list of hid-devices, plain pointers are
sufficient.

Tested-by: Josep Sanchez Ferreres <josep.sanchez.ferreres@est.fib.upc.edu>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Acked-by: Ping Cheng <pingc@wacom.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

2 files changed, 21 insertions, 6 deletions

diff --git a/drivers/hid/wacom_sys.c b/drivers/hid/wacom_sys.c
index f0568a7e6de9..b3c2395aef3b 100644
--- a/drivers/hid/wacom_sys.c
+++ b/drivers/hid/wacom_sys.c
@@ -524,6 +524,11 @@ static int wacom_add_shared_data(struct hid_device *hdev)
 
         wacom_wac->shared = &data->shared;
 
+        if (wacom_wac->features.device_type == BTN_TOOL_FINGER)
+                wacom_wac->shared->touch = hdev;
+        else if (wacom_wac->features.device_type == BTN_TOOL_PEN)
+                wacom_wac->shared->pen = hdev;
+
 out:
         mutex_unlock(&wacom_udev_list_lock);
         return retval;
@@ -541,14 +546,22 @@ static void wacom_release_shared_data(struct kref *kref)
         kfree(data);
 }
 
-static void wacom_remove_shared_data(struct wacom_wac *wacom)
+static void wacom_remove_shared_data(struct wacom *wacom)
 {
         struct wacom_hdev_data *data;
+        struct wacom_wac *wacom_wac = &wacom->wacom_wac;
+
+        if (wacom_wac->shared) {
+                data = container_of(wacom_wac->shared, struct wacom_hdev_data,
+                                    shared);
+
+                if (wacom_wac->shared->touch == wacom->hdev)
+                        wacom_wac->shared->touch = NULL;
+                else if (wacom_wac->shared->pen == wacom->hdev)
+                        wacom_wac->shared->pen = NULL;
 
-        if (wacom->shared) {
-                data = container_of(wacom->shared, struct wacom_hdev_data, shared);
                 kref_put(&data->kref, wacom_release_shared_data);
-                wacom->shared = NULL;
+                wacom_wac->shared = NULL;
         }
 }
 
@@ -1527,7 +1540,7 @@ fail_register_inputs:
         wacom_clean_inputs(wacom);
         wacom_destroy_battery(wacom);
 fail_battery:
-        wacom_remove_shared_data(wacom_wac);
+        wacom_remove_shared_data(wacom);
 fail_shared_data:
         wacom_clean_inputs(wacom);
 fail_allocate_inputs:
@@ -1550,7 +1563,7 @@ static void wacom_remove(struct hid_device *hdev)
         if (hdev->bus == BUS_BLUETOOTH)
                 device_remove_file(&hdev->dev, &dev_attr_speed);
         wacom_destroy_battery(wacom);
-        wacom_remove_shared_data(&wacom->wacom_wac);
+        wacom_remove_shared_data(wacom);
 
         hid_set_drvdata(hdev, NULL);
         kfree(wacom);
diff --git a/drivers/hid/wacom_wac.h b/drivers/hid/wacom_wac.h
index 021ee1c1980a..e42efbe3338c 100644
--- a/drivers/hid/wacom_wac.h
+++ b/drivers/hid/wacom_wac.h
@@ -169,6 +169,8 @@ struct wacom_shared {
         unsigned touch_max;
         int type;
         struct input_dev *touch_input;
+        struct hid_device *pen;
+        struct hid_device *touch;
 };
 
 struct hid_data {