Bring back HardwareSerial.

To make this happen, we need to have <board/board.h> tell us whether
or not it's got each of the USARTs. Do that with BOARD_HAVE_USARTn,
for n = 1,...,6. This lets us define HardwareSerial instances only
when appropriate, and gets rid of some board-specific hacks we'd
accumulated.

The new <libmaple/usart.h> now has a convenience function for
determining the bus rate by using the appropriate STM32_PCLKx macro,
so we can shave a uint32 per instance, which is nice given that
they're all going to be in memory. This changes the constructor
arguments, but the API only specifies the semantics of the predefined
instances, so this is still backwards-compatible. (We should look into
storing the instances in Flash -- they don't change, after all.)

We don't actually need struct usart_dev's definition in
HardwareSerial.h, so replace it with a forward declaration and include
<libmaple/usart.h> it in HardwareSerial.cpp instead.

Assert some copyrights.

Signed-off-by: Marti Bolivar <mbolivar@leaflabs.com>

7 files changed, 50 insertions, 6 deletions

diff --git a/wirish/boards/VLDiscovery/include/board/board.h b/wirish/boards/VLDiscovery/include/board/board.h
index 04d21c7..c54abc1 100644
--- a/wirish/boards/VLDiscovery/include/board/board.h
+++ b/wirish/boards/VLDiscovery/include/board/board.h
@@ -45,6 +45,12 @@
 
 /* Number of USARTs/UARTs whose pins are broken out to headers */
 #define BOARD_NR_USARTS         3
+#define BOARD_HAVE_USART1       1
+#define BOARD_HAVE_USART2       1
+#define BOARD_HAVE_USART3       1
+#define BOARD_HAVE_UART4        0
+#define BOARD_HAVE_UART5        0
+#define BOARD_HAVE_USART6       0
 
 /* Default USART pin numbers (not considering AFIO remap) */
 #define BOARD_USART1_TX_PIN     7
diff --git a/wirish/boards/maple/include/board/board.h b/wirish/boards/maple/include/board/board.h
index 49f5b9a..ed89fee 100644
--- a/wirish/boards/maple/include/board/board.h
+++ b/wirish/boards/maple/include/board/board.h
@@ -39,8 +39,15 @@
 #define BOARD_BUTTON_PIN        38
 #define BOARD_LED_PIN           13
 
-/* Number of USARTs/UARTs whose pins are broken out to headers */
+/* Number of USARTs/UARTs whose pins are broken out to headers, and
+ * macros saying which ones they are. */
 #define BOARD_NR_USARTS         3
+#define BOARD_HAVE_USART1       1
+#define BOARD_HAVE_USART2       1
+#define BOARD_HAVE_USART3       1
+#define BOARD_HAVE_UART4        0
+#define BOARD_HAVE_UART5        0
+#define BOARD_HAVE_USART6       0
 
 /* Default USART pin numbers (not considering AFIO remap) */
 #define BOARD_USART1_TX_PIN     7
diff --git a/wirish/boards/maple_RET6/include/board/board.h b/wirish/boards/maple_RET6/include/board/board.h
index 1a0365a..3291498 100644
--- a/wirish/boards/maple_RET6/include/board/board.h
+++ b/wirish/boards/maple_RET6/include/board/board.h
@@ -36,17 +36,20 @@
 #ifndef _BOARDS_MAPLE_RET6_H_
 #define _BOARDS_MAPLE_RET6_H_
 
-/* A few of these values will seem strange given that it's a
- * high-density board. */
-
 #define CYCLES_PER_MICROSECOND  72
 #define SYSTICK_RELOAD_VAL      71999 /* takes a cycle to reload */
 
 #define BOARD_BUTTON_PIN        38
 #define BOARD_LED_PIN           13
 
-/* Note: UART4 and UART5 have pins which aren't broken out :( */
+/* UART4 and UART5 have pins which aren't broken out :( */
 #define BOARD_NR_USARTS         3
+#define BOARD_HAVE_USART1       1
+#define BOARD_HAVE_USART2       1
+#define BOARD_HAVE_USART3       1
+#define BOARD_HAVE_UART4        0
+#define BOARD_HAVE_UART5        0
+#define BOARD_HAVE_USART6       0
 #define BOARD_USART1_TX_PIN     7
 #define BOARD_USART1_RX_PIN     8
 #define BOARD_USART2_TX_PIN     1
diff --git a/wirish/boards/maple_mini/include/board/board.h b/wirish/boards/maple_mini/include/board/board.h
index bfba46d..8ba91ce 100644
--- a/wirish/boards/maple_mini/include/board/board.h
+++ b/wirish/boards/maple_mini/include/board/board.h
@@ -43,6 +43,12 @@
 #define BOARD_LED_PIN             33
 
 #define BOARD_NR_USARTS           3
+#define BOARD_HAVE_USART1         1
+#define BOARD_HAVE_USART2         1
+#define BOARD_HAVE_USART3         1
+#define BOARD_HAVE_UART4          0
+#define BOARD_HAVE_UART5          0
+#define BOARD_HAVE_USART6         0
 #define BOARD_USART1_TX_PIN       26
 #define BOARD_USART1_RX_PIN       25
 #define BOARD_USART2_TX_PIN       9
diff --git a/wirish/boards/maple_native/include/board/board.h b/wirish/boards/maple_native/include/board/board.h
index 397afaf..a4f8896 100644
--- a/wirish/boards/maple_native/include/board/board.h
+++ b/wirish/boards/maple_native/include/board/board.h
@@ -43,6 +43,12 @@
 #define BOARD_BUTTON_PIN        6
 
 #define BOARD_NR_USARTS         5
+#define BOARD_HAVE_USART1       1
+#define BOARD_HAVE_USART2       1
+#define BOARD_HAVE_USART3       1
+#define BOARD_HAVE_UART4        1
+#define BOARD_HAVE_UART5        1
+#define BOARD_HAVE_USART6       0
 #define BOARD_USART1_TX_PIN     24
 #define BOARD_USART1_RX_PIN     25
 #define BOARD_USART2_TX_PIN     50
diff --git a/wirish/boards/olimex_stm32_h103/include/board/board.h b/wirish/boards/olimex_stm32_h103/include/board/board.h
index b312e26..46367ac 100644
--- a/wirish/boards/olimex_stm32_h103/include/board/board.h
+++ b/wirish/boards/olimex_stm32_h103/include/board/board.h
@@ -42,6 +42,12 @@
 
 /* Number of USARTs/UARTs whose pins are broken out to headers */
 #define BOARD_NR_USARTS         3
+#define BOARD_HAVE_USART1       1
+#define BOARD_HAVE_USART2       1
+#define BOARD_HAVE_USART3       1
+#define BOARD_HAVE_UART4        0
+#define BOARD_HAVE_UART5        0
+#define BOARD_HAVE_USART6       0
 
 /* Default USART pin numbers (not considering AFIO remap) */
 #define BOARD_USART1_TX_PIN     3
diff --git a/wirish/boards/st_stm3220g_eval/include/board/board.h b/wirish/boards/st_stm3220g_eval/include/board/board.h
index 08b935e..f99a585 100644
--- a/wirish/boards/st_stm3220g_eval/include/board/board.h
+++ b/wirish/boards/st_stm3220g_eval/include/board/board.h
@@ -27,7 +27,11 @@
 /**
  * @file   wirish/boards/st_stm3220g_eval/include/board/board.h
  * @author Marti Bolivar <mbolivar@leaflabs.com>
- * @brief  STM3220G-EVAL board header.
+ * @brief  STM3220G-EVAL board stub header.
+ *
+ * This (and the corresponding board.cpp) needs to be fixed and
+ * fleshed out. Do it later? Maybe someone who wants support for this
+ * board will do it.
  */
 
 #ifndef _BOARD_ST_STM3220G_EVAL_H_
@@ -40,6 +44,12 @@
 #define BOARD_LED_PIN           0
 
 #define BOARD_NR_USARTS         0
+#define BOARD_HAVE_USART1       0
+#define BOARD_HAVE_USART2       0
+#define BOARD_HAVE_USART3       0
+#define BOARD_HAVE_UART4        0
+#define BOARD_HAVE_UART5        0
+#define BOARD_HAVE_USART6       0
 #define BOARD_NR_SPI            0
 #define BOARD_NR_GPIO_PINS      6
 #define BOARD_NR_PWM_PINS       0