Add stm32_clockenable() to support recovery from deep sleep low-power usage modes

git-svn-id: https://nuttx.svn.sourceforge.net/svnroot/nuttx/trunk@5000 7fd9a85b-ad96-42d3-883c-3090e2eb8679

1 files changed, 67 insertions, 0 deletions

diff --git a/nuttx/arch/arm/src/stm32/stm32_rcc.c b/nuttx/arch/arm/src/stm32/stm32_rcc.c
index 47a4b550f..49943baa3 100644
--- a/nuttx/arch/arm/src/stm32/stm32_rcc.c
+++ b/nuttx/arch/arm/src/stm32/stm32_rcc.c
@@ -90,6 +90,27 @@
  * Public Functions
  ****************************************************************************/
 
+/************************************************************************************
+ * Name: stm32_clockconfig
+ *
+ * Description:
+ *   Called to establish the clock settings based on the values in board.h.  This
+ *   function (by default) will reset most everything, enable the PLL, and enable
+ *   peripheral clocking for all periperipherals enabled in the NuttX configuration
+ *   file.
+ *
+ *   If CONFIG_ARCH_BOARD_STM32_CUSTOM_CLOCKCONFIG is defined, then clocking will
+ *   be enabled by an externally provided, board-specific function called
+ *   stm32_board_clockconfig().
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Value:
+ *   None
+ *
+ ************************************************************************************/
+
 void stm32_clockconfig(void)
 {
   /* Make sure that we are starting in the reset state */
@@ -114,3 +135,49 @@ void stm32_clockconfig(void)
 
   rcc_enableperipherals();
 }
+
+/************************************************************************************
+ * Name: stm32_clockenable
+ *
+ * Description:
+ *   Re-enable the clock and restore the clock settings based on settings in board.h.
+ *   This function is only available to support low-power modes of operation:  When
+ *   re-awakening from deep-sleep modes, it is necessary to re-enable/re-start the
+ *   PLL
+ *
+ *   This functional performs a subset of the operations performed by
+ *   stm32_clockconfig():  It does not reset any devices, and it does not reset the
+ *   currenlty enabled peripheral clocks.
+ *
+ *   If CONFIG_ARCH_BOARD_STM32_CUSTOM_CLOCKCONFIG is defined, then clocking will
+ *   be enabled by an externally provided, board-specific function called
+ *   stm32_board_clockconfig().
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Value:
+ *   None
+ *
+ ************************************************************************************/
+
+#ifdef CONFIG_PM
+void stm32_clockenable(void);
+{
+#if defined(CONFIG_ARCH_BOARD_STM32_CUSTOM_CLOCKCONFIG)
+
+  /* Invoke Board Custom Clock Configuration */
+
+  stm32_board_clockconfig();
+
+#else
+
+  /* Invoke standard, fixed clock configuration based on definitions in board.h */
+
+  stm32_stdclockconfig();
+
+#endif
+}
+#endif
+
+