WiFi: Add support for setting channel width

src/confd/src/hardware.c

@@ -359,14 +359,55 @@ static void wifi_gen_ssid_config(FILE *hostapd, struct lyd_node *cif, struct lyd
 	free(secret);
 }
 
+/*
+ * Center channel for 80MHz VHT/HE operation.
+ * 5GHz 80MHz groups: 36-48(42), 52-64(58), 100-112(106),
+ *                    116-128(122), 132-144(138), 149-161(155)
+ */
+static int wifi_center_chan_80(int ch)
+{
+	static const int grp[][2] = {
+		{36, 42}, {52, 58}, {100, 106}, {116, 122}, {132, 138}, {149, 155}
+	};
+	int i;
+
+	for (i = 0; i < 6; i++)
+		if (ch >= grp[i][0] && ch < grp[i][0] + 16)
+			return grp[i][1];
+	return 0;
+}
+
+/*
+ * Center channel for 160MHz VHT/HE operation.
+ * 5GHz 160MHz groups: 36-64(50), 100-128(114)
+ */
+static int wifi_center_chan_160(int ch)
+{
+	if (ch >= 36 && ch <= 64)
+		return 50;
+	if (ch >= 100 && ch <= 128)
+		return 114;
+	return 0;
+}
+
+/* HT40 secondary channel direction: lower channel in pair uses +, upper uses - */
+static const char *wifi_ht40_dir(int ch)
+{
+	return ((ch / 4) % 2) ? "[HT40+]" : "[HT40-]";
+}
+
 /* Helper: Write radio-specific configuration */
 static void wifi_gen_radio_config(FILE *hostapd, struct lyd_node *radio_node)
 {
-	const char *country, *channel, *band;
+	const char *country, *channel, *band, *width;
+	int ch = 0;
 
 	country = lydx_get_cattr(radio_node, "country-code");
 	band = lydx_get_cattr(radio_node, "band");
 	channel = lydx_get_cattr(radio_node, "channel");
+	width = lydx_get_cattr(radio_node, "channel-width");
+	if (channel && strcmp(channel, "auto"))
+		ch = atoi(channel);
 
 	if (country)
 		fprintf(hostapd, "country_code=%s\n", country);
@@ -460,6 +501,49 @@ static void wifi_gen_radio_config(FILE *hostapd, struct lyd_node *radio_node)
 		/* 802.11ax (WiFi 6) always enabled for better performance */
 		fprintf(hostapd, "ieee80211ax=1\n");
 
+		/*
+		 * Channel width configuration.
+		 * - HT (802.11n): ht_capab [HT40+] or [HT40-]
+		 * - VHT (802.11ac): vht_oper_chwidth 0=20/40, 1=80, 2=160
+		 * - HE (802.11ax): he_oper_chwidth follows VHT values
+		 * Without explicit width, hostapd uses driver defaults.
+		 */
+		if (width && strcmp(width, "auto")) {
+			if (!strcmp(width, "20MHz")) {
+				fprintf(hostapd, "ht_capab=\n");
+				if (strcmp(band, "2.4GHz")) {
+					fprintf(hostapd, "vht_oper_chwidth=0\n");
+					fprintf(hostapd, "he_oper_chwidth=0\n");
+				}
+			} else if (!strcmp(width, "40MHz")) {
+				fprintf(hostapd, "ht_capab=%s\n", ch ? wifi_ht40_dir(ch) : "[HT40+]");
+				if (strcmp(band, "2.4GHz")) {
+					fprintf(hostapd, "vht_oper_chwidth=0\n");
+					fprintf(hostapd, "he_oper_chwidth=0\n");
+				}
+			} else if (!strcmp(width, "80MHz") && ch) {
+				int center = wifi_center_chan_80(ch);
+
+				fprintf(hostapd, "ht_capab=%s\n", wifi_ht40_dir(ch));
+				fprintf(hostapd, "vht_oper_chwidth=1\n");
+				fprintf(hostapd, "he_oper_chwidth=1\n");
+				if (center) {
+					fprintf(hostapd, "vht_oper_centr_freq_seg0_idx=%d\n", center);
+					fprintf(hostapd, "he_oper_centr_freq_seg0_idx=%d\n", center);
+				}
+			} else if (!strcmp(width, "160MHz") && ch) {
+				int center = wifi_center_chan_160(ch);
+
+				fprintf(hostapd, "ht_capab=%s\n", wifi_ht40_dir(ch));
+				fprintf(hostapd, "vht_oper_chwidth=2\n");
+				fprintf(hostapd, "he_oper_chwidth=2\n");
+				if (center) {
+					fprintf(hostapd, "vht_oper_centr_freq_seg0_idx=%d\n", center);
+					fprintf(hostapd, "he_oper_centr_freq_seg0_idx=%d\n", center);
+				}
+			}
+		}
+
 		/* Beamforming improves signal quality and range */
 		fprintf(hostapd, "he_su_beamformer=1\n");
 		fprintf(hostapd, "he_su_beamformee=1\n");

src/confd/yang/confd/infix-hardware.yang

@@ -21,6 +21,11 @@ module infix-hardware {
   contact      "kernelkit@googlegroups.com";
   description  "Vital Product Data augmentation of ieee-hardware and deviations.";
 
+  revision 2026-03-01 {
+    description "Add channel-width leaf for WiFi radio container.";
+    reference "internal";
+  }
+
   revision 2026-02-08 {
     description "Add GPS/GNSS receiver hardware class and container for time sync.";
     reference "internal";
@@ -98,6 +103,36 @@ module infix-hardware {
     description "WiFi frequency band selection.";
   }
 
+  typedef wifi-channel-width {
+    type enumeration {
+      enum "auto" {
+        description "Automatic selection based on hardware and regulatory capabilities.";
+      }
+      enum "20MHz" {
+        description "20 MHz channel width.";
+      }
+      enum "40MHz" {
+        description "40 MHz channel width (HT40).";
+      }
+      enum "80MHz" {
+        description "80 MHz channel width (VHT/HE, 5/6 GHz only).";
+      }
+      enum "160MHz" {
+        description "160 MHz channel width (VHT/HE, 5/6 GHz only).";
+      }
+    }
+    description
+      "WiFi channel bandwidth selection.
+
+       Wider channels provide higher throughput but increase
+       interference and reduce the number of non-overlapping channels.
+
+       Constraints:
+       - 40 MHz: Requires HT capable hardware
+       - 80 MHz: Requires VHT capable hardware (5/6 GHz only)
+       - 160 MHz: Requires VHT capable hardware (5/6 GHz only)";
+  }
+
   /*
    * Hardware class identities
    */
@@ -294,6 +329,22 @@ module infix-hardware {
            congestion in most environments.";
       }
 
+      leaf channel-width {
+        type wifi-channel-width;
+        default "auto";
+        must "../band != '2.4GHz' or . = 'auto' or . = '20MHz' or . = '40MHz'" {
+          error-message "80/160 MHz channel width requires 5 GHz or 6 GHz band.";
+        }
+        description
+          "Channel bandwidth.
+
+           Wider channels increase throughput but are more susceptible
+           to interference. Default 'auto' lets the driver select the
+           widest width supported by hardware and regulatory domain.
+
+           Only applicable in Access Point mode.";
+      }
+
       leaf probe-timeout {
         type uint8;
         description