ieee802154/submac: implement MR-OFDM timings

sys/include/net/ieee802154.h

@@ -120,6 +120,11 @@ extern "C" {
  */
 #define IEEE802154_ACK_TIMEOUT_SYMS     (54)
 
+/**
+ * @brief Symbol time for IEEE 802.15.4 MR-OFDM in µs
+ */
+#define IEEE802154_MR_OFDM_SYMBOL_TIME_US   (120)
+
 /**
  * @brief value of measured power when RSSI is zero.
  *
@@ -283,6 +288,20 @@ extern const uint8_t ieee802154_addr_bcast[IEEE802154_ADDR_BCAST_LEN];
 #define CONFIG_IEEE802154_MR_OQPSK_DEFAULT_RATE     (2U)
 #endif
 
+/**
+ * @brief IEEE802.15.4 MR-OFDM default modulation option
+ */
+#ifndef CONFIG_IEEE802154_MR_OFDM_DEFAULT_OPTION
+#define CONFIG_IEEE802154_MR_OFDM_DEFAULT_OPTION    (2U)
+#endif
+
+/**
+ * @brief IEEE802.15.4 MR-OFDM default Modulation & Coding Scheme
+ */
+#ifndef CONFIG_IEEE802154_MR_OFDM_DEFAULT_SCHEME
+#define CONFIG_IEEE802154_MR_OFDM_DEFAULT_SCHEME    (2U)
+#endif
+
 /**
  * @brief IEEE802.15.4 default PANID
  */

sys/include/net/ieee802154/radio.h

@@ -468,6 +468,15 @@ typedef struct {
     uint8_t rate_mode;                  /**< rate mode       */
 } ieee802154_mr_oqpks_conf_t;
 
+/**
+ * @brief extension for IEEE 802.15.4g MR-ODFM PHY
+ */
+typedef struct {
+    ieee802154_phy_conf_t super;        /**< common settings */
+    uint8_t option;                     /**< OFDM Option */
+    uint8_t scheme;                     /**< Modulation & Coding Scheme */
+} ieee802154_mr_odmf_conf_t;
+
 /**
  * @brief IEEE 802.15.4 radio operations
  */

sys/net/link_layer/ieee802154/submac.c

@@ -516,6 +516,44 @@ static inline uint16_t _mr_oqpsk_csma_backoff_period_us(const ieee802154_mr_oqpk
          + IEEE802154G_ATURNAROUNDTIME_US;
 }
 
+/*
+ * MR-OFDM timing calculations
+ *
+ * The standard unfortunately does not list the formula, instead it has to be pieced together
+ * from scattered information and tables in the IEEE 802.15.4 document - may contain errors.
+ */
+
+static unsigned _mr_ofdm_frame_duration(uint8_t option, uint8_t scheme, uint8_t bytes)
+{
+    /* Table 150 - phySymbolsPerOctet values for MR-OFDM PHY, IEEE 802.15.4g-2012 */
+    static const uint8_t quot[] = { 3, 3, 6, 12, 18, 24, 36 };
+
+    --option;
+    /* phyMaxFrameDuration = phySHRDuration + phyPHRDuration
+     *                     + ceiling [(aMaxPHYPacketSize + 1) x phySymbolsPerOctet] */
+    const unsigned phySHRDuration = 6;
+    const unsigned phyPHRDuration = option ? 6 : 3;
+    const unsigned phyPDUDuration = ((bytes + 1) * (1 << option) + quot[scheme] - 1)
+                                  / quot[scheme];
+
+    return (phySHRDuration + phyPHRDuration + phyPDUDuration) * IEEE802154_MR_OFDM_SYMBOL_TIME_US;
+}
+
+static inline uint16_t _mr_ofdm_csma_backoff_period_us(const ieee802154_mr_odmf_conf_t *conf)
+{
+    (void)conf;
+
+    return IEEE802154_CCA_DURATION_IN_SYMBOLS * IEEE802154_MR_OFDM_SYMBOL_TIME_US
+         + IEEE802154G_ATURNAROUNDTIME_US;
+}
+
+static inline uint16_t _mr_ofdm_ack_timeout_us(const ieee802154_mr_odmf_conf_t *conf)
+{
+    return _mr_ofdm_csma_backoff_period_us(conf)
+         + IEEE802154G_ATURNAROUNDTIME_US
+         + _mr_ofdm_frame_duration(conf->option, conf->scheme, IEEE802154_ACK_FRAME_LEN);
+}
+
 static int ieee802154_submac_config_phy(ieee802154_submac_t *submac,
                                         const ieee802154_phy_conf_t *conf)
 {
@@ -529,6 +567,12 @@ static int ieee802154_submac_config_phy(ieee802154_submac_t *submac,
         submac->ack_timeout_us = _mr_oqpsk_ack_timeout_us((void *)conf);
         submac->csma_backoff_us = _mr_oqpsk_csma_backoff_period_us((void *)conf);
         break;
+#endif
+#ifdef MODULE_NETDEV_IEEE802154_MR_OFDM
+    case IEEE802154_PHY_MR_OFDM:
+        submac->ack_timeout_us = _mr_ofdm_ack_timeout_us((void *)conf);
+        submac->csma_backoff_us = _mr_ofdm_csma_backoff_period_us((void *)conf);
+        break;
 #endif
     case IEEE802154_PHY_NO_OP:
     case IEEE802154_PHY_DISABLED:
@@ -612,6 +656,9 @@ int ieee802154_submac_init(ieee802154_submac_t *submac, const network_uint16_t *
         ieee802154_phy_conf_t super;
 #ifdef MODULE_NETDEV_IEEE802154_MR_OQPSK
         ieee802154_mr_oqpks_conf_t mr_oqpsk;
+#endif
+#ifdef MODULE_NETDEV_IEEE802154_MR_OFDM
+        ieee802154_mr_odmf_conf_t mr_ofdm;
 #endif
     } conf;
 
@@ -621,6 +668,12 @@ int ieee802154_submac_init(ieee802154_submac_t *submac, const network_uint16_t *
         conf.mr_oqpsk.rate_mode = CONFIG_IEEE802154_MR_OQPSK_DEFAULT_RATE;
     }
 #endif
+#ifdef MODULE_NETDEV_IEEE802154_MR_OFDM
+    if (submac->phy_mode == IEEE802154_PHY_MR_OFDM) {
+        conf.mr_ofdm.option = CONFIG_IEEE802154_MR_OFDM_DEFAULT_OPTION;
+        conf.mr_ofdm.scheme = CONFIG_IEEE802154_MR_OFDM_DEFAULT_SCHEME;
+    }
+#endif
 
     conf.super.phy_mode = submac->phy_mode;
     conf.super.channel = submac->channel_num;