stm32f1: stm32.h: Put MCU section first, allow overrides.

Put the section defining MCU-specific values before the other
sections. Surround the density-specific defines with #ifndef/#endif
pairs. This allows any of the settings in the STM32F1 stm32.h to be
overridden on a per-MCU basis. That's hopefully useful to e.g. people
porting libmaple to STM32F100 MCUs, which have slower clocks.

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

1 files changed, 47 insertions, 30 deletions

diff --git a/libmaple/stm32f1/include/series/stm32.h b/libmaple/stm32f1/include/series/stm32.h
index 26c45a2..ed51ae5 100644
--- a/libmaple/stm32f1/include/series/stm32.h
+++ b/libmaple/stm32f1/include/series/stm32.h
@@ -36,6 +36,41 @@
 extern "C" {
 #endif
 
+#define STM32_MCU_SERIES                STM32_SERIES_F1
+
+/*
+ * MCU-specific values.
+ *
+ * You can use this section to override any of the below settings on a
+ * per-MCU basis. For example, if your MCU has different STM32_PCLK1
+ * or STM32_PCLK2 values, you can set them here and the values for
+ * STM32F103 microcontrollers set below won't take effect.
+ */
+
+#if defined(MCU_STM32F103RB)
+#   define STM32_NR_GPIO_PORTS          4
+#   define STM32_SRAM_END               ((void*)0x20005000)
+
+#elif defined(MCU_STM32F103ZE)
+#   define STM32_NR_GPIO_PORTS          7
+#   define STM32_SRAM_END               ((void*)0x20010000)
+
+#elif defined(MCU_STM32F103CB)
+    /* This STM32_NR_GPIO_PORTS is not stricly true, but only pins 0
+     * and exist, and they're used for OSC (e.g. on e.g. LeafLabs
+     * Maple Mini), so we'll live with this for now. */
+#   define STM32_NR_GPIO_PORTS          3
+#   define STM32_SRAM_END               ((void*)0x20005000)
+
+#elif defined(MCU_STM32F103RE)
+#   define STM32_NR_GPIO_PORTS          4
+#   define STM32_SRAM_END               ((void*)0x20010000)
+
+#else
+#error "Unrecognized STM32F1 MCU, or no MCU specified. Add something like " \
+       "-DMCU_STM32F103RB to your compiler arguments."
+#endif
+
 /*
  * Clock configuration.
  */
@@ -57,46 +92,28 @@ extern "C" {
  */
 
 #ifdef STM32_MEDIUM_DENSITY
+#   ifndef STM32_NR_INTERRUPTS
 #   define STM32_NR_INTERRUPTS          43
+#   endif
+
+#   ifndef STM32_HAVE_FSMC
 #   define STM32_HAVE_FSMC              0
+#   endif
+
 #elif defined(STM32_HIGH_DENSITY)
+#   ifndef STM32_NR_INTERRUPTS
 #   define STM32_NR_INTERRUPTS          60
+#   endif
+
+#   ifndef STM32_HAVE_FSMC
 #   define STM32_HAVE_FSMC              1
+#   endif
+
 #else
 #error "Unsupported STM32F1 density, or no density specified. Add something " \
        "like -DSTM32_MEDIUM_DENSITY to your compiler arguments."
 #endif
 
-/*
- * Series- and MCU-specific values.
- */
-
-#define STM32_MCU_SERIES                STM32_SERIES_F1
-
-#if defined(MCU_STM32F103RB)
-#   define STM32_NR_GPIO_PORTS          4
-#   define STM32_SRAM_END               ((void*)0x20005000)
-
-#elif defined(MCU_STM32F103ZE)
-#   define STM32_NR_GPIO_PORTS          7
-#   define STM32_SRAM_END               ((void*)0x20010000)
-
-#elif defined(MCU_STM32F103CB)
-    /* This STM32_NR_GPIO_PORTS is not stricly true, but only pins 0
-     * and exist, and they're used for OSC (e.g. on e.g. LeafLabs
-     * Maple Mini), so we'll live with this for now. */
-#   define STM32_NR_GPIO_PORTS          3
-#   define STM32_SRAM_END               ((void*)0x20005000)
-
-#elif defined(MCU_STM32F103RE)
-#   define STM32_NR_GPIO_PORTS          4
-#   define STM32_SRAM_END               ((void*)0x20010000)
-
-#else
-#error "Unrecognized STM32F1 MCU, or no MCU specified. Add something like " \
-       "-DMCU_STM32F103RB to your compiler arguments."
-#endif
-
 #ifdef __cplusplus
 }
 #endif