Add pin mapping code.

This commit also introduces board directories and moves board
specific config into the appropriate board directory.

boards/stm32f4xx-af.csv was extracted from the STM32F4xx datasheet
and hand-tweaked.

make-pins.py takes boards/stm32f4xx-af.csv, boards/stm32f4xx-prefix.c,
and boards/BOARD-NAME/pins.csv as input and generates the file
build/pins_BOARD_NAME.c

The generated pin file for PYBOARD4 looks like this:
https://gist.github.com/dhylands/9063231

The generated pins file includes all of the supported alternate
functions, and includes upsupported alternate functions as comments.

See the commnet block at the top of stm/pin_map.c for details on
how to use the pin mapper.

I also went ahead and modified stm/gpio.c to use the pin mapper.

1 files changed, 34 insertions, 0 deletions

diff --git a/stm/boards/stm32f4xx-prefix.c b/stm/boards/stm32f4xx-prefix.c
new file mode 100644
index 0000000000..e68de4cf4e
--- /dev/null
+++ b/stm/boards/stm32f4xx-prefix.c
@@ -0,0 +1,34 @@
+// stm32fxx-prefix.c becomes the initial portion of the generated pins file.
+
+#include <stdio.h>
+#include <stdint.h>
+#include <stm32f4xx.h>
+
+#include "misc.h"
+#include "mpconfig.h"
+#include "qstr.h"
+#include "obj.h"
+
+#include "pin.h"
+
+#define AF(af_idx, af_fn, af_unit, af_type, af_ptr) \
+{ \
+    { &pin_af_obj_type }, \
+    .idx = (af_idx), \
+    .fn = AF_FN_ ## af_fn, \
+    .unit = (af_unit), \
+    .type = AF_PIN_TYPE_ ## af_fn ## _ ## af_type, \
+    .af_fn = (af_ptr) \
+}
+
+#define PIN(p_port, p_pin, p_num_af, p_af) \
+{ \
+    { &pin_obj_type }, \
+    .name = #p_port #p_pin, \
+    .port = PORT_ ## p_port, \
+    .pin = (p_pin), \
+    .num_af = (p_num_af), \
+    .pin_mask = (1 << ((p_pin) & 0x0f)), \
+    .gpio = GPIO ## p_port, \
+    .af = p_af, \
+}