Link report descriptors to known sensors.

Since HID buffers always start by a reportID we can access the corresponding
report descriptor in O(1).  Having a list of sensors attached to each report
descriptor makes it easier to update all of them with only on I/O request.

Note that sensors are attached in depency order on every report list.

From David Higgs.

diff --git a/sys/dev/usb/upd.c b/sys/dev/usb/upd.c
index 93b06e9..fc5e0b2 100644 (file)
--- a/sys/dev/usb/upd.c
+++ b/sys/dev/usb/upd.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: upd.c,v 1.18 2015/04/30 10:00:50 mpi Exp $ */
+/*     $OpenBSD: upd.c,v 1.19 2015/04/30 10:09:31 mpi Exp $ */
 
 /*
  * Copyright (c) 2014 Andre de Oliveira <andre@openbsd.org>
@@ -79,8 +79,8 @@ static struct upd_usage_entry upd_usage_roots[] = {
 #define UPD_MAX_SENSORS        (nitems(upd_usage_batdep) + nitems(upd_usage_roots))
 
 struct upd_report {
-       size_t          size;
-       int             enabled;
+       size_t                          size;
+       SLIST_HEAD(, upd_sensor)        sensors;
 };
 
 SLIST_HEAD(upd_sensor_head, upd_sensor);
@@ -90,6 +90,7 @@ struct upd_sensor {
        int                             attached;
        struct upd_sensor_head          children;
        SLIST_ENTRY(upd_sensor)         dep_next;
+       SLIST_ENTRY(upd_sensor)         rep_next;
 };
 
 struct upd_softc {
@@ -183,6 +184,8 @@ upd_attach(struct device *parent, struct device *self, void *aux)
 
        sc->sc_reports = mallocarray(sc->sc_max_repid,
            sizeof(struct upd_report), M_USBDEV, M_WAITOK | M_ZERO);
+       for (i = 0; i < sc->sc_max_repid; i++)
+               SLIST_INIT(&sc->sc_reports[i].sensors);
        sc->sc_sensors = mallocarray(UPD_MAX_SENSORS,
            sizeof(struct upd_sensor), M_USBDEV, M_WAITOK | M_ZERO);
        for (i = 0; i < UPD_MAX_SENSORS; i++)
@@ -214,6 +217,7 @@ upd_attach_sensor_tree(struct upd_softc *sc, void *desc, int size,
        struct hid_item           item;
        struct upd_usage_entry   *entry;
        struct upd_sensor        *sensor;
+       struct upd_report        *report;
        int                       i;
 
        for (i = 0; i < nentries; i++) {
@@ -243,11 +247,11 @@ upd_attach_sensor_tree(struct upd_softc *sc, void *desc, int size,
                upd_attach_sensor_tree(sc, desc, size, entry->nchildren,
                    entry->children, &sensor->children);
 
-               if (sc->sc_reports[item.report_ID].enabled)
-                       continue;
-               sc->sc_reports[item.report_ID].size = hid_report_size(desc,
-                   size, item.kind, item.report_ID);
-               sc->sc_reports[item.report_ID].enabled = 1;
+               report = &sc->sc_reports[item.report_ID];
+               if (SLIST_EMPTY(&report->sensors))
+                       report->size = hid_report_size(desc,
+                           size, item.kind, item.report_ID);
+               SLIST_INSERT_HEAD(&report->sensors, sensor, rep_next);
        }
 }
 
@@ -288,7 +292,7 @@ upd_refresh(void *arg)
 
        for (repid = 0; repid < sc->sc_max_repid; repid++) {
                report = &sc->sc_reports[repid];
-               if (!report->enabled)
+               if (SLIST_EMPTY(&report->sensors))
                        continue;
 
                memset(buf, 0x0, sizeof(buf));