i.MX6 Add more debug instrumentation; Fix setting of CCM register.

arch/arm/src/imx6/imx_boot.c

@@ -398,12 +398,14 @@ void up_boot(void)
    */
 
   imx_setupmappings();
+  imx_lowputc('A');
 
   /* Provide a special mapping for the OCRAM interrupt vector positioned in
    * high memory.
    */
 
   imx_vectormapping();
+  imx_lowputc('B');
 
 #ifdef CONFIG_ARCH_RAMFUNCS
   /* Copy any necessary code sections from FLASH to RAM.  The correct
@@ -417,11 +419,14 @@ void up_boot(void)
       *dest++ = *src++;
     }
 
+  imx_lowputc('C');
+
   /* Flush the copied RAM functions into physical RAM so that will
    * be available when fetched into the I-Cache.
    */
 
   arch_clean_dcache((uintptr_t)&_sramfuncs, (uintptr_t)&_eramfuncs)
+  imx_lowputc('D');
 #endif
 
   /* Setup up vector block.  _vector_start and _vector_end are exported from
@@ -429,19 +434,23 @@ void up_boot(void)
    */
 
   imx_copyvectorblock();
+  imx_lowputc('E');
 
   /* Disable the watchdog timer */
 
   imx_wdtdisable();
+  imx_lowputc('F');
 
   /* Initialize clocking to settings provided by board-specific logic */
 
   imx_clockconfig();
+  imx_lowputc('G');
 
 #ifdef CONFIG_ARCH_FPU
   /* Initialize the FPU */
 
   arm_fpuconfig();
+  imx_lowputc('H');
 #endif
 
   /* Perform board-specific initialization,  This must include:
@@ -455,6 +464,7 @@ void up_boot(void)
    */
 
   imx_board_initialize();
+  imx_lowputc('I');
 
 #ifdef NEED_SDRAM_REMAPPING
   /* SDRAM was configured in a temporary state to support low-level
@@ -463,6 +473,7 @@ void up_boot(void)
    */
 
   imx_remap();
+  imx_lowputc('J');
 #endif
 
 #ifdef CONFIG_BOOT_SDRAM_DATA
@@ -471,11 +482,13 @@ void up_boot(void)
    */
 
   arm_data_initialize();
+  imx_lowputc('K');
 #endif
 
   /* Perform common, low-level chip initialization (might do nothing) */
 
   imx_lowsetup();
+  imx_lowputc('L');
 
 #ifdef USE_EARLYSERIALINIT
   /* Perform early serial initialization if we are going to use the serial
@@ -483,5 +496,7 @@ void up_boot(void)
    */
 
   imx_earlyserialinit();
+  imx_lowputc('M');
 #endif
+  imx_lowputc('\n');
 }

arch/arm/src/imx6/imx_clockconfig.c

@@ -81,7 +81,7 @@ void imx_clockconfig(void)
   /* Make certain that the ipg_clk is enabled */
 
   regval  = getreg32(IMX_CCM_CCGR5);
-  regval &= (CCM_CCGR5_CG12_MASK);
+  regval &= ~(CCM_CCGR5_CG12_MASK);
   regval |= CCM_CCGR5_CG12(CCM_CCGR_ALLMODES);
   putreg32(regval, IMX_CCM_CCGR5);
 }

arch/arm/src/imx6/imx_lowputc.c

@@ -53,6 +53,8 @@
 #include "imx_gpio.h"
 #include "imx_lowputc.h"
 
+#include "up_internal.h"
+
 #include <arch/board/board.h> /* Include last:  has dependencies */
 
 /****************************************************************************
@@ -158,6 +160,7 @@ static const struct uart_config_s g_console_config =
 
 void imx_lowsetup(void)
 {
+#ifndef CONFIG_SUPPRESS_UART_CONFIG
 #ifdef IMX_HAVE_UART
   uint32_t regval;
 
@@ -287,6 +290,7 @@ void imx_lowsetup(void)
   (void)imx_uart_configure(IMX_CONSOLE_VBASE, &g_console_config);
 #endif
 #endif /* IMX_HAVE_UART */
+#endif /* CONFIG_SUPPRESS_UART_CONFIG */
 }
 
 /************************************************************************************
@@ -566,4 +570,48 @@ int imx_uart_configure(uint32_t base, FAR const struct uart_config_s *config)
 
   return OK;
 }
-#endif /* IMX_HAVE_UART */
+#endif /* IMX_HAVE_UART */
+
+/************************************************************************************
+ * Name: imx_lowputc
+ *
+ * Description:
+ *   Output a byte with as few system dependencies as possible
+ *
+ ************************************************************************************/
+
+#if defined(IMX_HAVE_UART) && defined(CONFIG_DEBUG)
+void imx_lowputc(int ch)
+{
+  /* Poll the TX fifo trigger level bit of the UART status register. When the TXFE
+   * bit is non-zero, the TX Buffer FIFO is empty.
+   */
+
+  while ((getreg32(IMX_CONSOLE_VBASE + UART_USR2_OFFSET) & UART_USR2_TXFE) == 0);
+
+  /* If the character to output is a newline, then pre-pend a carriage return */
+
+  if (ch == '\n')
+    {
+      /* Send the carrage return by writing it into the UART_TXD register. */
+
+      putreg32((uint32_t)'\r', IMX_CONSOLE_VBASE + UART_TXD_OFFSET);
+
+      /* Wait for the tranmsit regiser to be emptied. When the TXFE bit is non-zero,
+       * the TX Buffer FIFO is empty.
+       */
+
+      while ((getreg32(IMX_CONSOLE_VBASE + UART_USR2_OFFSET) & UART_USR2_TXFE) == 0);
+    }
+
+  /* Send the character by writing it into the UART_TXD register. */
+
+  putreg32((uint32_t)ch, IMX_CONSOLE_VBASE + UART_TXD_OFFSET);
+
+  /* Wait for the tranmsit regiser to be emptied. When the TXFE bit is non-zero,
+   * the TX Buffer FIFO is empty.
+   */
+
+  while ((getreg32(IMX_CONSOLE_VBASE + UART_USR2_OFFSET) & UART_USR2_TXFE) == 0);
+}
+#endif

arch/arm/src/imx6/imx_lowputc.h

@@ -95,4 +95,18 @@ void imx_lowsetup(void);
 int imx_uart_configure(uint32_t base, FAR const struct uart_config_s *config);
 #endif
 
+/************************************************************************************
+ * Name: imx_lowputc
+ *
+ * Description:
+ *   Output a byte with as few system dependencies as possible
+ *
+ ************************************************************************************/
+
+#if defined(IMX_HAVE_UART) && defined(CONFIG_DEBUG)
+void imx_lowputc(int ch);
+#else
+#  define imx_lowputc(ch)
+#endif
+
 #endif /* __ARCH_ARM_SRC_IMX6_IMX_LOWPUTC_H */

arch/arm/src/imx6/imx_serial.c

@@ -540,8 +540,8 @@ static inline void imx_waittxready(struct imx_uart_s *priv)
 
 static int imx_setup(struct uart_dev_s *dev)
 {
-#ifndef CONFIG_SUPPRESS_UART_CONFIG
   struct imx_uart_s *priv = (struct imx_uart_s *)dev->priv;
+#ifndef CONFIG_SUPPRESS_UART_CONFIG
   struct uart_config_s config;
   int ret;