usart.h: Deprecate rx_buf field in usart_dev.

nzmichaelh rightly argues that actual RX buffers should be
heap-allocated, to avoid wastage for unused devices.  Deprecate the
field for 0.0.12, since that's coming out soon.  This will let us get
rid of this field in master immediately after 0.0.12 gets shipped.

1 files changed, 4 insertions, 1 deletions

diff --git a/libmaple/usart.h b/libmaple/usart.h
index 0ad1405..e747e65 100644
--- a/libmaple/usart.h
+++ b/libmaple/usart.h
@@ -237,7 +237,10 @@ typedef struct usart_dev {
     usart_reg_map *regs;             /**< Register map */
     ring_buffer *rb;                 /**< RX ring buffer */
     uint32 max_baud;                 /**< Maximum baud */
-    uint8 rx_buf[USART_RX_BUF_SIZE]; /**< Actual RX buffer used by rb */
+    uint8 rx_buf[USART_RX_BUF_SIZE]; /**< @brief Deprecated.
+                                      * Actual RX buffer used by rb.
+                                      * This field will be removed in
+                                      * a future release. */
     rcc_clk_id clk_id;               /**< RCC clock information */
     nvic_irq_num irq_num;            /**< USART NVIC interrupt */
 } usart_dev;