From d4f39742ea49607db668d3dcdbaffc1a055e0987 Mon Sep 17 00:00:00 2001
From: Gerson Fernando Budke <nandojve@gmail.com>
Date: Sun, 26 Jan 2020 14:55:44 -0300
Subject: [PATCH] drivers: ieee802154: rf2xx: Add SRAM read method

Add SRAM read method to enable advanced uses on at86rf2xx driver.

Signed-off-by: Gerson Fernando Budke <nandojve@gmail.com>
---
 drivers/ieee802154/ieee802154_rf2xx_iface.c | 48 ++++++++++++++++++++-
 drivers/ieee802154/ieee802154_rf2xx_iface.h | 17 +++++++-
 2 files changed, 63 insertions(+), 2 deletions(-)

diff --git a/drivers/ieee802154/ieee802154_rf2xx_iface.c b/drivers/ieee802154/ieee802154_rf2xx_iface.c
index c6c4a960257..a35351d8888 100644
--- a/drivers/ieee802154/ieee802154_rf2xx_iface.c
+++ b/drivers/ieee802154/ieee802154_rf2xx_iface.c
@@ -1,7 +1,7 @@
 /* ieee802154_rf2xx_iface.c - ATMEL RF2XX IEEE 802.15.4 Interface */
 
 /*
- * Copyright (c) 2019 Gerson Fernando Budke
+ * Copyright (c) 2019-2020 Gerson Fernando Budke
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -248,3 +248,49 @@ void rf2xx_iface_frame_write(struct device *dev,
 	LOG_DBG("Frame W: PhyStatus: %02X. length: %02X", status, length);
 	LOG_HEXDUMP_DBG(data, length, "payload");
 }
+
+void rf2xx_iface_sram_read(struct device *dev,
+			    u8_t address,
+			    u8_t *data,
+			    u8_t length)
+{
+	const struct rf2xx_context *ctx = dev->driver_data;
+	u8_t cmd = RF2XX_RF_CMD_SRAM_R;
+	u8_t status[2];
+
+	const struct spi_buf tx_buf[2] = {
+		{
+			.buf = &cmd,
+			.len = 1
+		},
+		{
+			.buf = &address,
+			.len = 1
+		},
+	};
+	const struct spi_buf_set tx = {
+		.buffers = tx_buf,
+		.count = 2
+	};
+	const struct spi_buf rx_buf[2] = {
+		{
+			.buf = status,
+			.len = 2
+		},
+		{
+			.buf = data,
+			.len = length
+		},
+	};
+	const struct spi_buf_set rx = {
+		.buffers = rx_buf,
+		.count = 2
+	};
+
+	if (spi_transceive(ctx->spi, &ctx->spi_cfg, &tx, &rx) != 0) {
+		LOG_ERR("Failed to exec rf2xx_sram_read");
+	}
+
+	LOG_DBG("SRAM R: length: %02X, status: %02X", length, status[0]);
+	LOG_HEXDUMP_DBG(data, length, "content");
+}
diff --git a/drivers/ieee802154/ieee802154_rf2xx_iface.h b/drivers/ieee802154/ieee802154_rf2xx_iface.h
index d434323cf64..17e6a76062a 100644
--- a/drivers/ieee802154/ieee802154_rf2xx_iface.h
+++ b/drivers/ieee802154/ieee802154_rf2xx_iface.h
@@ -1,7 +1,7 @@
 /* ieee802154_rf2xx_iface.h - ATMEL RF2XX transceiver interface */
 
 /*
- * Copyright (c) 2019 Gerson Fernando Budke
+ * Copyright (c) 2019-2020 Gerson Fernando Budke
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -107,4 +107,19 @@ void rf2xx_iface_frame_write(struct device *dev,
 			     u8_t *data,
 			     u8_t length);
 
+/**
+ * @brief Reads sram data from the transceiver
+ *
+ * This function reads the sram data of the transceiver.
+ *
+ * @param[in]   dev     Transceiver device instance
+ * @param[in]   address Start address to be read
+ * @param[out]  data    Pointer to the location to store data
+ * @param[in]   length  Number of bytes to be read from the sram space
+ */
+void rf2xx_iface_sram_read(struct device *dev,
+			    u8_t address,
+			    u8_t *data,
+			    u8_t length);
+
 #endif /* ZEPHYR_DRIVERS_IEEE802154_IEEE802154_RF2XX_IFACE_H_ */