drivers: lora: Add ability to force enable LDRO

Allows Enabling LDRO all the time via DTS

Signed-off-by: Camille BAUD <mail@massdriver.space>

Author: VynDragon

drivers/lora/lora_basics_modem/lbm_common.c

@@ -81,7 +81,8 @@ int lbm_lora_config(const struct device *dev, struct lora_modem_config *lora_con
 		.mod_params = {
 			.sf = lora_config->datarate,
 			.cr = lora_config->coding_rate,
-			.ldro = LORA_LDRO(lora_config->datarate, lora_config->bandwidth),
+			.ldro = LORA_LDRO(lora_config->datarate, lora_config->bandwidth)
+				| (config->force_ldro ? 1 : 0),
 		},
 		.pkt_params = {
 			.preamble_len_in_symb = lora_config->preamble_len,

drivers/lora/lora_basics_modem/lbm_common.h

@@ -34,6 +34,7 @@ enum lbm_modem_mode {
 struct lbm_lora_config_common {
 	/* LBM radio abstration layer structure */
 	ralf_t ralf;
+	bool force_ldro;
 };
 
 /* Common LBM modem data, must be first element of device data */

drivers/lora/lora_basics_modem/lbm_sx126x.c

@@ -501,6 +501,7 @@ static int sx126x_init(const struct device *dev)
 #define SX126X_DEFINE(node_id, sx_variant)                                                         \
 	static const struct lbm_sx126x_config config_##node_id = {                                 \
 		.lbm_common.ralf = RALF_SX126X_INSTANTIATE(DEVICE_DT_GET(node_id)),                \
+		.lbm_common.force_ldro = DT_PROP(node_id, force_ldro),                             \
 		.spi = SPI_DT_SPEC_GET(                                                            \
 			node_id, SPI_WORD_SET(8) | SPI_OP_MODE_MASTER | SPI_TRANSFER_MSB),         \
 		.reset = GPIO_DT_SPEC_GET(node_id, reset_gpios),                                   \

drivers/lora/lora_basics_modem/lbm_sx127x.c

@@ -441,6 +441,7 @@ static int sx127x_driver_init(const struct device *dev)
 	static struct lbm_sx127x_data data_##node_id;                                              \
 	static const struct lbm_sx127x_config config_##node_id = {                                 \
 		.lbm_common.ralf = RALF_SX127X_INSTANTIATE(&data_##node_id.radio),                 \
+		.lbm_common.force_ldro = DT_PROP(node_id, force_ldro),                             \
 		.spi = SPI_DT_SPEC_GET(                                                            \
 			node_id, SPI_WORD_SET(8) | SPI_OP_MODE_MASTER | SPI_TRANSFER_MSB),         \
 		.reset = GPIO_DT_SPEC_GET(node_id, reset_gpios),                                   \

dts/bindings/lora/semtech,sx126x-base.yaml

@@ -70,3 +70,9 @@ properties:
     type: boolean
     description: |
       Use the internal LDO instead of the internal DCDC. Increases power consumption.
+
+  force-ldro:
+    type: boolean
+    description: |
+      Force usage of Low Data Rate Optimization even in cases where the symbol time is shorter than
+      16.38ms. Useful for designs using no TCXO or with bad heat dissipation.

dts/bindings/lora/semtech,sx127x-base.yaml

@@ -61,3 +61,9 @@ properties:
     type: int
     description: |
       Delay which has to be applied after enabling TCXO power.
+
+  force-ldro:
+    type: boolean
+    description: |
+      Force usage of Low Data Rate Optimization even in cases where the symbol time is shorter than
+      16.38ms. Useful for designs using no TCXO or with bad heat dissipation.