From d3c6cfc0ee29774ee8985dc11d2f47d9af54ce3c Mon Sep 17 00:00:00 2001
From: Andreas Sandberg <andreas@sandberg.pp.se>
Date: Thu, 16 Apr 2020 00:29:41 +0100
Subject: [PATCH] drivers: lora: Add a continuous wave test API

Add an API to transmit a continuous wave at a fixed frequency. This
functionality is useful to test the radio in a lab setup.

Signed-off-by: Andreas Sandberg <andreas@sandberg.pp.se>
---
 drivers/lora/sx1276.c  |  9 +++++++++
 include/drivers/lora.h | 34 ++++++++++++++++++++++++++++++++++
 2 files changed, 43 insertions(+)

diff --git a/drivers/lora/sx1276.c b/drivers/lora/sx1276.c
index 26a4795f627..134549564d3 100644
--- a/drivers/lora/sx1276.c
+++ b/drivers/lora/sx1276.c
@@ -446,6 +446,13 @@ static int sx1276_lora_config(struct device *dev,
 	return 0;
 }
 
+static int sx1276_lora_test_cw(struct device *dev, u32_t frequency,
+			       s8_t tx_power, u16_t duration)
+{
+	Radio.SetTxContinuousWave(frequency, tx_power, duration);
+	return 0;
+}
+
 /* Initialize Radio driver callbacks */
 const struct Radio_s Radio = {
 	.Init = SX1276Init,
@@ -468,6 +475,7 @@ const struct Radio_s Radio = {
 	.IrqProcess = NULL,
 	.RxBoosted = NULL,
 	.SetRxDutyCycle = NULL,
+	.SetTxContinuousWave = SX1276SetTxContinuousWave,
 };
 
 static int sx1276_lora_init(struct device *dev)
@@ -538,6 +546,7 @@ static const struct lora_driver_api sx1276_lora_api = {
 	.config = sx1276_lora_config,
 	.send = sx1276_lora_send,
 	.recv = sx1276_lora_recv,
+	.test_cw = sx1276_lora_test_cw,
 };
 
 DEVICE_AND_API_INIT(sx1276_lora, DT_INST_LABEL(0),
diff --git a/include/drivers/lora.h b/include/drivers/lora.h
index d15337cf8e0..b2cb016f731 100644
--- a/include/drivers/lora.h
+++ b/include/drivers/lora.h
@@ -75,10 +75,20 @@ typedef int (*lora_api_send)(struct device *dev,
 typedef int (*lora_api_recv)(struct device *dev, u8_t *data, u8_t size,
 			     k_timeout_t timeout, s16_t *rssi, s8_t *snr);
 
+/**
+ * @typedef lora_api_test_cw()
+ * @brief Callback API for transmitting a continuous wave
+ *
+ * @see lora_test_cw() for argument descriptions.
+ */
+typedef int (*lora_api_test_cw)(struct device *dev, u32_t frequency,
+				s8_t tx_power, u16_t duration);
+
 struct lora_driver_api {
 	lora_api_config config;
 	lora_api_send	send;
 	lora_api_recv	recv;
+	lora_api_test_cw test_cw;
 };
 
 /**
@@ -139,4 +149,28 @@ static inline int lora_recv(struct device *dev, u8_t *data, u8_t size,
 	return api->recv(dev, data, size, timeout, rssi, snr);
 }
 
+/**
+ * @brief Transmit an unmodulated continuous wave at a given frequency
+ *
+ * @note Only use this functionality in a test setup where the
+ * transmission does not interfere with other devices.
+ *
+ * @param dev       LoRa device
+ * @param frequency Output frequency (Hertz)
+ * @param tx_power  TX power (dBm)
+ * @param duration  Transmission duration in seconds.
+ * @return 0 on success, negative on error
+ */
+static inline int lora_test_cw(struct device *dev, u32_t frequency,
+			       s8_t tx_power, u16_t duration)
+{
+	const struct lora_driver_api *api = dev->driver_api;
+
+	if (!api->test_cw) {
+		return -ENOTSUP;
+	}
+
+	return api->test_cw(dev, frequency, tx_power, duration);
+}
+
 #endif	/* ZEPHYR_INCLUDE_DRIVERS_LORA_H_ */