uwb: infrastructure for handling Relinquish Request IEs

The structures and event handler needed to handle Relinish Request IEs
received from neighbors. Nothing is done with these IEs yet.

Signed-off-by: Stefano Panella <[e-mail]>
Signed-off-by: David Vrabel <[e-mail]>

drivers/uwb/Makefile

···
 	drp-ie.o	\
 	est.o		\
 	ie.o		\
+	ie-rcv.o	\
 	lc-dev.o	\
 	lc-rc.o		\
 	neh.o		\

drivers/uwb/ie-rcv.c

···
+/*
+ * Ultra Wide Band
+ * IE Received notification handling.
+ *
+ * Copyright (C) 2008 Cambridge Silicon Radio Ltd.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/errno.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/bitmap.h>
+#include "uwb-internal.h"
+
+/*
+ * Process an incoming IE Received notification.
+ */
+int uwbd_evt_handle_rc_ie_rcv(struct uwb_event *evt)
+{
+	int result = -EINVAL;
+	struct device *dev = &evt->rc->uwb_dev.dev;
+	struct uwb_rc_evt_ie_rcv *iercv;
+	size_t iesize;
+
+	/* Is there enough data to decode it? */
+	if (evt->notif.size < sizeof(*iercv)) {
+		dev_err(dev, "IE Received notification: Not enough data to "
+			"decode (%zu vs %zu bytes needed)\n",
+			evt->notif.size, sizeof(*iercv));
+		goto error;
+	}
+	iercv = container_of(evt->notif.rceb, struct uwb_rc_evt_ie_rcv, rceb);
+	iesize = le16_to_cpu(iercv->wIELength);
+
+	dev_dbg(dev, "IE received, element ID=%d\n", iercv->IEData[0]);
+
+	if (iercv->IEData[0] == UWB_RELINQUISH_REQUEST_IE) {
+		dev_warn(dev, "unhandled Relinquish Request IE\n");
+	}
+
+	return 0;
+error:
+	return result;
+}

drivers/uwb/uwb-internal.h

···
 void uwbd_flush(struct uwb_rc *rc);
 
 /* UWB event handlers */
+extern int uwbd_evt_handle_rc_ie_rcv(struct uwb_event *);
 extern int uwbd_evt_handle_rc_beacon(struct uwb_event *);
 extern int uwbd_evt_handle_rc_beacon_size(struct uwb_event *);
 extern int uwbd_evt_handle_rc_bpoie_change(struct uwb_event *);

drivers/uwb/uwbd.c

···
 /** Table of handlers for and properties of the UWBD Radio Control Events */
 static
 struct uwbd_event uwbd_events[] = {
+	[UWB_RC_EVT_IE_RCV] = {
+		.handler = uwbd_evt_handle_rc_ie_rcv,
+		.name = "IE_RECEIVED"
+	},
 	[UWB_RC_EVT_BEACON] = {
 		.handler = uwbd_evt_handle_rc_beacon,
 		.name = "BEACON_RECEIVED"

include/linux/uwb/spec.h

···
 	UWB_DRP_REASON_MODIFIED,
 };
 
+/** Relinquish Request Reason Codes ([ECMA-368] table 113) */
+enum uwb_relinquish_req_reason {
+	UWB_RELINQUISH_REQ_REASON_NON_SPECIFIC = 0,
+	UWB_RELINQUISH_REQ_REASON_OVER_ALLOCATION,
+};
+
 /**
  *  DRP Notification Reason Codes (WHCI 0.95 [3.1.4.9])
  */
···
 	UWB_APP_SPEC_PROBE_IE = 15,
 	UWB_IDENTIFICATION_IE = 19,
 	UWB_MASTER_KEY_ID_IE = 20,
+	UWB_RELINQUISH_REQUEST_IE = 21,
 	UWB_IE_WLP = 250, /* WiMedia Logical Link Control Protocol WLP 0.99 */
 	UWB_APP_SPEC_IE = 255,
 };
···
 	struct uwb_ie_hdr	hdr;
 	DECLARE_BITMAP(bmp, UWB_NUM_MAS);
 } __attribute__((packed));
+
+/* Relinqish Request IE ([ECMA-368] section 16.8.19). */
+struct uwb_relinquish_request_ie {
+        struct uwb_ie_hdr       hdr;
+        __le16                  relinquish_req_control;
+        struct uwb_dev_addr     dev_addr;
+        struct uwb_drp_alloc    allocs[];
+} __attribute__((packed));
+
+static inline int uwb_ie_relinquish_req_reason_code(struct uwb_relinquish_request_ie *ie)
+{
+	return (le16_to_cpu(ie->relinquish_req_control) >> 0) & 0xf;
+}
+
+static inline void uwb_ie_relinquish_req_set_reason_code(struct uwb_relinquish_request_ie *ie,
+							 int reason_code)
+{
+	u16 ctrl = le16_to_cpu(ie->relinquish_req_control);
+	ctrl = (ctrl & ~(0xf << 0)) | (reason_code << 0);
+	ie->relinquish_req_control = cpu_to_le16(ctrl);
+}
 
 /**
  * The Vendor ID is set to an OUI that indicates the vendor of the device.