SAM4S: Add macros to manage peripheral clocks

Documentation/NuttxPortingGuide.html

@@ -12,7 +12,7 @@
       <h1><big><font color="#3c34ec">
         <i>NuttX RTOS Porting Guide</i>
       </font></big></h1>
-      <p>Last Updated: March 20, 2013</p>
+      <p>Last Updated: June 11, 2013</p>
     </td>
   </tr>
 </table>
@@ -46,7 +46,8 @@
         <a href="#boardlogic">2.4.2.1 Board Specific Logic</a><br>
         <a href="#boardconfigsubdirs">2.4.2.2 Board Specific Configuration Sub-Directories</a>
       </ul>
-      <a href="#supportedboards">2.4.3 Supported Boards</a>
+      <a href="#supportedboards">2.4.3 Supported Boards</a><br>
+      <a href="#newboardconfig">2.4.4 Adding a New Board Configuration</a>
     </ul>
     <a href="#DirStructDrivers">2.5 nuttx/drivers/</a><br>
     <a href="#DirStructFs">2.6 nuttx/fs/</a><br>
@@ -1021,6 +1022,84 @@
   is available to build these toolchains under Linux or Cygwin.
 </blockquote></small></p>
 
+<h3><a name="newboardconfig">2.4.4 Adding a New Board Configuration</a></h3>
+<p>
+  Okay, so you have created a new board configuration directory.
+  Now, how do you hook this board into the configuration system so that you can select with <code>make menuconfig</code>?
+</p>
+<p>
+  You will need modify the file <code>configs/Kconfig</code>.
+  Let's look at the STM32F4-Discovery configuration in the <code>Kconfig</code> file and see how we would add a new board directory to the configuration.
+  For this configuration let's say that you new board resides in the directory <code>configs/myboard</code>;
+  It uses an MCU selected with <code>CONFIG_ARCH_CHIP_MYMCU</code>; and you want the board to be selected with <code>CONFIG_ARCH_BOARD_MYBOARD</code>.
+  Then here is how you can clone the STM32F4-Discovery configuration in <code>configs/Kconfig</code> to support your new board configuration.
+</p>
+<p>
+  In <code>configs/Kconfig</code> for the stm32f4-discovery, you will see a configuration definition like this:
+<p>
+<ul><pre>
+config ARCH_BOARD_STM32F4_DISCOVERY
+    bool "STMicro STM32F4-Discovery board"
+    depends on ARCH_CHIP_STM32F407VG
+    select ARCH_HAVE_LEDS
+    select ARCH_HAVE_BUTTONS
+    select ARCH_HAVE_IRQBUTTONS
+    ---help---
+        STMicro STM32F4-Discovery board based on the STMicro STM32F407VGT6 MCU.
+</pre></ul>
+<p>
+  The above selects the STM32F4-Discovery board.
+  The <code>select</code> lines say that the board has both LEDs and buttons and that the board can generate interrupts from the button presses.
+  You can just copy the above configuration definition to a new location (notice that they the configurations are in alphabetical order).
+  Then you should edit the configuration to support your board.
+  The final configuration definition might look something like:
+</p>
+<ul><pre>
+config ARCH_BOARD_MYBOARD
+    bool "My very own board configuration"
+    depends on ARCH_CHIP_MYMCU
+    select ARCH_HAVE_LEDS
+    select ARCH_HAVE_BUTTONS
+    select ARCH_HAVE_IRQBUTTONS
+    ---help---
+        This options selects the board configuration for my very own board
+        based on the MYMCU processor.
+</pre></ul>
+<p>
+  Later in the <code>configs/Kconfig</code> file, you will see a long, long string configuration with lots of defaults like this:
+</p>
+<ul><pre>
+config ARCH_BOARD
+    string
+    default "amber"               if ARCH_BOARD_AMBER
+    default "avr32dev1"           if ARCH_BOARD_AVR32DEV1
+    default "c5471evm"            if ARCH_BOARD_C5471EVM
+...
+    default "stm32f4discovery"    if ARCH_BOARD_STM32F4_DISCOVERY
+...
+</pre></ul>
+<p>
+  This logic will assign string value to a configuration variable called <code>CONFIG_ARCH_BOARD</code> that will name the directory where the board-specific files reside.
+  In our case, these files reside in <code>configs/myboard</code> and we add the following to the long list of defaults (again in alphabetical order):
+</p>
+<ul><pre>
+    default "myboar"              if ARCH_BOARD_MYBOARD
+</pre></ul>
+<p>
+  Now the build system knows where to find your board configuration!
+</p>
+<p>
+  And finally, add something like this near the bottom of <code>configs/myboard</code>:
+</p>
+<ul><pre>
+if ARCH_BOARD_MYBOARD
+source "configs/myboard/Kconfig"
+endif
+</pre></ul>
+<p>
+  This includes additional, board-specific configuration variabled defintion in <code>configs/myboard/Kconfig</code>.
+</p>
+
 <h2>2.5 <a name="DirStructDrivers">nuttx/drivers</a></h2>
 
 <p>
@@ -1078,7 +1157,7 @@ drivers/
 |   |-- Kconfig
 |   |-- Make.defs
 |   `-- <i>(Common USB host driver source files)</i>
-|-- wirelss/
+|-- wireless/
 |   |-- Kconfig
 |   |-- Make.defs
 |   `-- <i>(Common wireless driver source files)</i>