HID: Add an input configured notification callback

A hid device may create several input devices, and a driver may need
to prepare or finalize the configuration per input device. Currently,
there is no sane way for a driver to know when a device has been
configured. This patch adds a callback providing that information.

Reviewed-and-tested-by: Benjamin Tissoires <benjamin.tissoires@enac.fr>
Tested-by: Ping Cheng <pingc@wacom.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Henrik Rydberg <rydberg@euromail.se>

2 files changed, 12 insertions, 2 deletions

diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c
index 811bfad64609..d917c0d53685 100644
--- a/drivers/hid/hid-input.c
+++ b/drivers/hid/hid-input.c
@@ -1154,6 +1154,7 @@ static void report_features(struct hid_device *hid)
 
 int hidinput_connect(struct hid_device *hid, unsigned int force)
 {
+        struct hid_driver *drv = hid->driver;
         struct hid_report *report;
         struct hid_input *hidinput = NULL;
         struct input_dev *input_dev;
@@ -1228,6 +1229,8 @@ int hidinput_connect(struct hid_device *hid, unsigned int force)
                                  * UGCI) cram a lot of unrelated inputs into the
                                  * same interface. */
                                 hidinput->report = report;
+                                if (drv->input_configured)
+                                        drv->input_configured(hid, hidinput);
                                 if (input_register_device(hidinput->input))
                                         goto out_cleanup;
                                 hidinput = NULL;
@@ -1235,8 +1238,12 @@ int hidinput_connect(struct hid_device *hid, unsigned int force)
                 }
         }
 
-        if (hidinput && input_register_device(hidinput->input))
-                goto out_cleanup;
+        if (hidinput) {
+                if (drv->input_configured)
+                        drv->input_configured(hid, hidinput);
+                if (input_register_device(hidinput->input))
+                        goto out_cleanup;
+        }
 
         return 0;
 
diff --git a/include/linux/hid.h b/include/linux/hid.h
index 42970de1b40c..f37da2803005 100644
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -626,6 +626,7 @@ struct hid_usage_id {
  * @report_fixup: called before report descriptor parsing (NULL means nop)
  * @input_mapping: invoked on input registering before mapping an usage
  * @input_mapped: invoked on input registering after mapping an usage
+ * @input_configured: invoked just before the device is registered
  * @feature_mapping: invoked on feature registering
  * @suspend: invoked on suspend (NULL means nop)
  * @resume: invoked on resume if device was not reset (NULL means nop)
@@ -670,6 +671,8 @@ struct hid_driver {
         int (*input_mapped)(struct hid_device *hdev,
                         struct hid_input *hidinput, struct hid_field *field,
                         struct hid_usage *usage, unsigned long **bit, int *max);
+        void (*input_configured)(struct hid_device *hdev,
+                                 struct hid_input *hidinput);
         void (*feature_mapping)(struct hid_device *hdev,
                         struct hid_field *field,
                         struct hid_usage *usage);