drivers: wifi: siwx91x: Add support for Enhanced Legacy Power Save

Siwx91x support a specific mode slightly better than the old legacy PS
mode.

This mode has to be set on the NWP boot, so it is not easy to configure
it during the runtime. Hence, this patch only provide a compile time
option to enable it.

Co-authored-by: Arunmani Alagarsamy <arunmani.a@silabs.com>
Signed-off-by: Arunmani Alagarsamy <arunmani.a@silabs.com>
Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>

Author: 2 people

drivers/wifi/siwx91x/Kconfig.siwx91x

@@ -14,6 +14,24 @@ config WIFI_SILABS_SIWX91X
 
 if WIFI_SILABS_SIWX91X
 
+config WIFI_SILABS_SIWX91X_ENHANCED_MAX_PSP
+	bool "Enhanced Max PSP Support"
+	default y
+	help
+	  Enable this option to allow the device to configure
+	  Enhanced Maximum Power Save (PSP) support during
+	  device initialization.
+
+	  **Advantages:**
+	  - Reduces power consumption during low traffic periods.
+	  - Automatically transitions to Fast PSP for improved responsiveness
+	    when traffic is high.
+
+	  **Limitations:**
+	  - Initially uses PS-Poll frames for power management, even if the
+	    user configures NULL frame-based.
+	  - Switches to NULL frame-based only when traffic increases.
+
 choice
 	prompt "Network stack"
 	default WIFI_SILABS_SIWX91X_NET_STACK_NATIVE

soc/silabs/silabs_siwx91x/siwg917/nwp.c

@@ -69,9 +69,11 @@ static void siwx91x_configure_sta_mode(sl_si91x_boot_configuration_t *boot_confi
 
 #ifdef CONFIG_WIFI_SILABS_SIWX91X
 	boot_config->ext_tcp_ip_feature_bit_map = SL_SI91X_CONFIG_FEAT_EXTENSION_VALID;
-	boot_config->config_feature_bit_map = SL_SI91X_ENABLE_ENHANCED_MAX_PSP;
 	boot_config->ext_custom_feature_bit_map |= SL_SI91X_EXT_FEAT_IEEE_80211W |
 			SL_SI91X_EXT_FEAT_FRONT_END_SWITCH_PINS_ULP_GPIO_4_5_0;
+	if (IS_ENABLED(CONFIG_WIFI_SILABS_SIWX91X_ENHANCED_MAX_PSP)) {
+		boot_config->config_feature_bit_map = SL_SI91X_ENABLE_ENHANCED_MAX_PSP;
+	}
 #endif
 
 #ifdef CONFIG_BT_SILABS_SIWX91X