Hi Henrik,

On Sun, Feb 3, 2013 at 1:27 PM, Henrik Rydberg [off-list ref] wrote:

Hi Benjamin,

quoted

This callback is called when the parsing of the report has been done
by hid-core (so after the calls to .event). The hid drivers can now
have access to the whole report by relying on the values stored in
the different fields.

Signed-off-by: Benjamin Tissoires <redacted>
---
 drivers/hid/hid-core.c | 4 ++++
 include/linux/hid.h    | 2 ++
 2 files changed, 6 insertions(+)

diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 5ae2cb1..b671e4e 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c

@@ -1195,6 +1195,7 @@ int hid_report_raw_event(struct hid_device *hid, int type, u8 *data, int size,
 {
      struct hid_report_enum *report_enum = hid->report_enum + type;
      struct hid_report *report;
+     struct hid_driver *hdrv;
      unsigned int a;
      int rsize, csize = size;
      u8 *cdata = data;

@@ -1231,6 +1232,9 @@ int hid_report_raw_event(struct hid_device *hid, int type, u8 *data, int size,
      if (hid->claimed != HID_CLAIMED_HIDRAW) {
              for (a = 0; a < report->maxfield; a++)
                      hid_input_field(hid, report->field[a], cdata, interrupt);
+             hdrv = hid->driver;
+             if (hdrv && hdrv->report)
+                     hdrv->report(hid, report);

I think this is more useful if called before the individual fields. In
fact, it seems raw_event() is already doing exactly that. No need for
a new callback, in other words.

I'm afraid this does not work:
- calling it before the individual fields is not possible unless more
intrusive changes to hid-core:
  * "hid_input_field" does the actual parsing of the input report, so
without the call the .value field is still set to the previous one
(not very useful then)
  * the "hid_input_field" requires to know the previous report, due to
Array type reports which send the current keys down, and not the
release.
- the raw_event() callback contains the report _unparsed_, which means
that it's up to the hid specific driver to split the fields depending
on the report descriptor (for instance, get the right bit for
tipswitch in a byte containing tipswitch, inrange, confidence,
contactId).
- the raw_event() mechanism was the one in place in the v1 of the
patch series, in which the new callback was asked.

Cheers,
Benjamin

quoted

      }

      if (hid->claimed & HID_CLAIMED_INPUT)

diff --git a/include/linux/hid.h b/include/linux/hid.h
index 828726c..e14b465 100644
--- a/include/linux/hid.h
+++ b/include/linux/hid.h

@@ -589,6 +589,7 @@ struct hid_usage_id {
  * @raw_event: if report in report_table, this hook is called (NULL means nop)
  * @usage_table: on which events to call event (NULL means all)
  * @event: if usage in usage_table, this hook is called (NULL means nop)
+ * @report: this hook is called after parsing a report (NULL means nop)
  * @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

@@ -627,6 +628,7 @@ struct hid_driver {
      const struct hid_usage_id *usage_table;
      int (*event)(struct hid_device *hdev, struct hid_field *field,
                      struct hid_usage *usage, __s32 value);
+     void (*report)(struct hid_device *hdev, struct hid_report *report);

      __u8 *(*report_fixup)(struct hid_device *hdev, __u8 *buf,
                      unsigned int *size);
--

1.8.1

Thanks,
Henrik