Add untested version of clock enable manager

stm-firmware/include/clock-enable-manager.h

@@ -0,0 +1,48 @@
+#ifndef __CLOCK_ENABLE_MANAGER_H__
+#define __CLOCK_ENABLE_MANAGER_H__
+
+#include <stdint.h>
+#include <stm32-gpio-macros.h>
+
+/**
+ * @brief The RCC Enable Manager uses static memory with a fixed maximum
+ */
+#define RCC_ENABLE_MANAGER_STATIC 1U
+
+#if RCC_ENABLE_MANAGER_STATIC
+#define RCC_ENABLE_MANAGER_COUNT 20U
+#else
+#error "RCC Enable Manager not yet implemented with dynamic memory"
+#endif
+
+/**
+ * @brief Enable Clock for peripheral by setting the corresponding bit (@p bit_no) to one
+ *
+ * This function also keeps a enable count on each bit that is set, in order to allow nested enables/disables
+ *
+ * If there is no more space to track a new register bit in memory (either due to the static limit or due to no remaining heap space),
+ * the function still enables the peripheral clock but does not track it and returns -1
+ *
+ * @param rcc_enable_register
+ * @param bit_no
+ *
+ * @return 0 if successful
+ */
+int rcc_manager_enable_clock(uint32_t *rcc_enable_register, uint8_t bit_no);
+
+/**
+ * @brief Disable clock for peripheral and decrement the enaböe-counter of that bit.
+ *
+ * If there is no bit entry in the counting table yet, teh peripheral clock is not disabled and error code
+ * -1 is returned.
+ *
+ * If the count reaches zero, the element is removed from the list to make room for new ones
+ *
+ * @param rcc_enable_register Register to disable the bit in
+ * @param bit_no Bit number (0 to 31) of the bit to disable
+ * @return 0 if successful
+ */
+int rcc_manager_disable_clock(uint32_t *rcc_enable_register, uint8_t bit_no);
+
+
+#endif /* __CLOCK_ENABLE_MANAGER_H__ */

stm-firmware/include/stm32-gpio-macros.h

@@ -8,4 +8,13 @@
 #define SETAF(PORT,PIN,AF)  PORT->AFR[(PIN < 8 ? 0 : 1)] |= AF << ((PIN < 8 ? PIN : (PIN - 8)) * 4)
 #define ANALOG(pin)  (0x03 << (pin * 2))
 
+#define BIOTMASK_TO_BITNO(x) (x&0x1?0:x&0x2?1:x&0x4?2:x&0x8?3: \
+		 x&0x10?4:x&0x20?5:x&0x40?6:x&0x80?7: \
+		 x&0x100?8:x&0x200?9:x&0x400?10:x&0x800?11: \
+		 x&0x1000?12:x&0x2000?13:x&0x4000?14:x&0x8000?15: \
+		 x&0x10000?16:x&0x20000?17:x&0x40000?18:x&0x80000?19: \
+		 x&0x100000?20:x&0x200000?21:x&0x400000?22:x&0x800000?23: \
+		 x&0x1000000?24:x&0x2000000?25:x&0x4000000?26:x&0x8000000?27: \
+		 x&0x10000000?28:x&0x20000000?29:x&0x40000000?30:x&0x80000000?31:32)
+
 #endif /* __STM32GPIOMACROS_H__ */