From a87259ebc699b7db57867e15c0ccc1f04ba94c08 Mon Sep 17 00:00:00 2001
From: patacongo <patacongo@42af7a65-404d-4744-a932-0658087f49c3>
Date: Fri, 19 Aug 2011 16:51:04 +0000
Subject: [PATCH] Add support for multiplexed SDIO pins from Uros

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@3898 42af7a65-404d-4744-a932-0658087f49c3
---
 ChangeLog                            |   2 +
 Documentation/NuttX.html             |  20 ++-
 Documentation/NuttxPortingGuide.html |  45 +++++-
 arch/arm/src/stm32/stm32_rcc.c       |  94 ++++++++++---
 arch/arm/src/stm32/stm32_rcc.h       |  15 +-
 arch/arm/src/stm32/stm32_sdio.c      |  43 ++++++
 configs/README.txt                   |  43 ++++--
 configs/vsn/README.txt               | 171 +----------------------
 configs/vsn/include/board.h          |   3 +
 configs/vsn/include/muxbus.h         |  84 ++++++++++++
 configs/vsn/src/Makefile             |   2 +-
 configs/vsn/src/boot.c               |   1 +
 configs/vsn/src/muxbus.c             | 198 +++++++++++++++++++++++++++
 configs/vsn/src/sif.c                |  92 ++++++++++++-
 configs/vsn/src/vsn.h                |   8 ++
 drivers/mmcsd/mmcsd_sdio.c           |  32 ++++-
 drivers/wireless/cc1101/cc1101.c     |  39 ++++++
 include/nuttx/sdio.h                 |  24 ++++
 18 files changed, 698 insertions(+), 218 deletions(-)
 create mode 100644 configs/vsn/include/muxbus.h
 create mode 100644 configs/vsn/src/muxbus.c

diff --git a/ChangeLog b/ChangeLog
index d8fc1d643b..188d2f6069 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -2009,3 +2009,5 @@
 	* confgs/twr-k60n512: Add Kinetics TWR-K60N512 NSH configuration.
 	* drivers/analog and include/nuttx/analog: Add ADC driver infrastructure
 	  and TI ADS1255 driver developed and submitted by Li Zhouy (Lzzy)).
+	* arch/arm/stm32/stm32_sdio.h and drvers/mmcsd/mmcsd.c:  Add logic to
+	  multiplex usage of the GPIO pins.
\ No newline at end of file
diff --git a/Documentation/NuttX.html b/Documentation/NuttX.html
index c854fd8b71..4b86fc39cb 100644
--- a/Documentation/NuttX.html
+++ b/Documentation/NuttX.html
@@ -8,7 +8,7 @@
   <tr align="center" bgcolor="#e4e4e4">
     <td>
       <h1><big><font color="#3c34ec"><i>NuttX RTOS</i></font></big></h1>
-      <p>Last Updated: August 18, 2011</p>
+      <p>Last Updated: August 19, 2011</p>
     </td>
   </tr>
 </table>
@@ -678,6 +678,21 @@
 </tr>
 </table></center>
 
+<tr>
+  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
+  <td bgcolor="#5eaee1">
+    <b>Analog Devices</b>
+  </td>
+</tr>
+<tr>
+  <td><br></td>
+  <td>
+    <p>
+      <li>Support for Analog-to-Digital converters.</li>
+    </p>
+</tr>
+</table></center>
+
 <p>
   <b>NuttX Add-Ons</b>.
   The following packages are available to extend the basic NuttX feature set:
@@ -2700,6 +2715,9 @@ nuttx-6.8 2011-xx-xx Gregory Nutt &lt;spudmonkey@racsa.co.cr&gt;
       (reported by Li Zhouy (Lzzy)).
     * 8/18/2011: The basic port to the FreeScale Kinetics TWR-K60N512 board is
       now functional.
+    * confgs/twr-k60n512: Add Kinetics TWR-K60N512 NSH configuration.
+    * drivers/analog and include/nuttx/analog: Add ADC driver infrastructure
+      and TI ADS1255 driver developed and submitted by Li Zhouy (Lzzy)).
 
 apps-6.8 2011-xx-xx Gregory Nutt &lt;spudmonkey@racsa.co.cr&gt;
 
diff --git a/Documentation/NuttxPortingGuide.html b/Documentation/NuttxPortingGuide.html
index a2b17b108c..2fda4d612b 100644
--- a/Documentation/NuttxPortingGuide.html
+++ b/Documentation/NuttxPortingGuide.html
@@ -12,7 +12,7 @@
       <h1><big><font color="#3c34ec">
         <i>NuttX RTOS Porting Guide</i>
       </font></big></h1>
-      <p>Last Updated: July 27, 2011</p>
+      <p>Last Updated: August 19, 2011</p>
     </td>
   </tr>
 </table>
@@ -730,6 +730,8 @@
       <code>setenv.sh</code>: This is a script that you can include that will be installed at
       the top level of the directory structure and can be sourced to set any
       necessary environment variables.
+      You will most likely have to customize the default <code>setenv.sh</code> script in order
+      for it to work correctly in your environment.
     </p>
   </li>
 </ul>
@@ -863,8 +865,8 @@
   </li>
 
   <li><code>configs/olimex-lpc2378</code>:
-	This port uses the Olimex-lpc2378 board and a GNU arm-elf toolchain under
-	Linux or Cygwin.  STATUS: ostest and NSH configurations available.
+    This port uses the Olimex-lpc2378 board and a GNU arm-elf toolchain under
+    Linux or Cygwin.  STATUS: ostest and NSH configurations available.
   </li>
 
   <li><code>configs/olimex-strp711</code>:
@@ -904,12 +906,12 @@
   </li>
 
   <li><code>configs/sam3u-ek</code>:
-	The port of NuttX to the Atmel SAM3U-EK development board.
+    The port of NuttX to the Atmel SAM3U-EK development board.
   </li>
 
   <li><code>configs/skp16c26</code>:
-	Renesas M16C processor on the Renesas SKP16C26 StarterKit.  This port
-	uses the GNU m32c toolchain.  STATUS:  The port is complete but untested
+    Renesas M16C processor on the Renesas SKP16C26 StarterKit.  This port
+    uses the GNU m32c toolchain.  STATUS:  The port is complete but untested
     due to issues with compiler internal errors.
   </li>
 
@@ -3847,6 +3849,21 @@ build
   </li>
 </ul>
 
+<h3>SDIO/SDHC driver</h3>
+<ul>
+  <li>
+    <code>CONFIG_SDIO_DMA</code>: SDIO driver supports DMA
+  </li>
+  <li>
+    <code>CONFIG_SDIO_MUXBUS</code>: Set this SDIO interface if the SDIO interface
+    or hardware resources are shared with other drivers.
+  </li>
+  <li>
+    <code>CONFIG_SDIO_WIDTH_D1_ONLY</code>: Select 1-bit transfer mode.  Default:
+    4-bit transfer mode.
+  </li>
+</ul>
+
 <h3>SDIO-based MMC/SD driver</h3>
 <ul>
   <li>
@@ -3977,6 +3994,22 @@ build
   </li>
 </ul>
 
+<h3>Analog Devices</h3>
+<ul>
+  <li>
+    <code>CONFIG_DAC</code>:
+    Enables general support for Digital-to-Analog conversion devices.
+  </li>
+  <li>
+    <code>CONFIG_ADC</code>:
+    Enables general support for Analog-to-Digital conversion devices.
+  </li>
+  <li>
+    <code>CONFIG_ADC_ADS125X</code>:
+    Adds support for the TI ADS 125x ADC.
+  </li>
+</ul>
+
 <h3>ENC28J60 Ethernet Driver Configuration Settings</h3>
 <ul>
   <li>
diff --git a/arch/arm/src/stm32/stm32_rcc.c b/arch/arm/src/stm32/stm32_rcc.c
index f39aa0d429..a9155f1a26 100755
--- a/arch/arm/src/stm32/stm32_rcc.c
+++ b/arch/arm/src/stm32/stm32_rcc.c
@@ -59,6 +59,22 @@
 
 #define HSERDY_TIMEOUT 256
 
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* Activity reference count, showing inactivity after start-up.
+ * Device drivers increment this count using rcclock() and rccunlock()
+ * 
+ * If this value goes beyond the range [0, MAX_RCCs] indicates
+ * reference count leakage (asymetric number of locks vs. unlocks) and
+ * system enters permanent active state.
+ */
+
+#ifdef CONFIG_STM32_RCCLOCK
+static int stm32_rcclock_count = 0; 
+#endif
+ 
 /****************************************************************************
  * Private Functions
  ****************************************************************************/
@@ -98,7 +114,6 @@ static inline void rcc_reset(void)
   putreg32(0, STM32_RCC_CIR);               /* Disable all interrupts */
 }
 
-
 static inline void rcc_enableahb(void)
 {
   uint32_t regval;
@@ -140,7 +155,6 @@ static inline void rcc_enableahb(void)
   putreg32(regval, STM32_RCC_AHBENR);   /* Enable peripherals */
 }
 
-
 static inline void rcc_enableapb1(void)
 {
   uint32_t regval;
@@ -292,7 +306,6 @@ static inline void rcc_enableapb1(void)
   putreg32(regval, STM32_RCC_APB1ENR);
 }
 
-
 static inline void rcc_enableapb2(void)
 {
   uint32_t regval;
@@ -374,14 +387,14 @@ static inline void rcc_enableapb2(void)
   putreg32(regval, STM32_RCC_APB2ENR);
 }
 
-
 #if !defined(CONFIG_ARCH_BOARD_STM32_CUSTOM_CLOCKCONFIG)
 
-/** Called to change to new clock based on settings in board.h
+/* Called to change to new clock based on settings in board.h
  * 
- *  NOTE:  This logic would need to be extended if you need to select low-
- *  power clocking modes!
- **/
+ *   NOTE:  This logic would need to be extended if you need to select low-
+ *   power clocking modes!
+ */
+ 
 static inline void stm32_stdclockconfig(void)
 {
   uint32_t regval;
@@ -469,7 +482,6 @@ static inline void stm32_stdclockconfig(void)
 }
 #endif
 
-
 /****************************************************************************
  * Public Functions
  ****************************************************************************/
@@ -501,22 +513,66 @@ void stm32_clockconfig(void)
   rcc_enableapb1();
 }
 
-
-/**
+/*
  * \todo Check for LSE good timeout and return with -1,
  *   possible ISR optimization? or at least ISR should be cough in case of failure
  */
+
 void stm32_rcc_enablelse(void)
 {
-    /* Enable LSE */
-    modifyreg16(STM32_RCC_BDCR, 0, RCC_BDCR_LSEON);
+  /* Enable LSE */
 
-    /* We could wait for ISR here ... */
-    while( !(getreg16(STM32_RCC_BDCR) & RCC_BDCR_LSERDY) ) up_waste();
+  modifyreg16(STM32_RCC_BDCR, 0, RCC_BDCR_LSEON);
+
+  /* We could wait for ISR here ... */
+
+  while( !(getreg16(STM32_RCC_BDCR) & RCC_BDCR_LSERDY) ) up_waste();
     
-    /* Select LSE as RTC Clock Source */
-    modifyreg16(STM32_RCC_BDCR, RCC_BDCR_RTCSEL_MASK, RCC_BDCR_RTCSEL_LSE);
+  /* Select LSE as RTC Clock Source */
+
+  modifyreg16(STM32_RCC_BDCR, RCC_BDCR_RTCSEL_MASK, RCC_BDCR_RTCSEL_LSE);
     
-    /* Enable Clock */
-    modifyreg16(STM32_RCC_BDCR, 0, RCC_BDCR_RTCEN);    
+  /* Enable Clock */
+
+  modifyreg16(STM32_RCC_BDCR, 0, RCC_BDCR_RTCEN);    
 }
+
+#ifdef CONFIG_STM32_RCCLOCK
+uint32_t stm32_rcclock(uint8_t domain_id)
+{
+  // THINK:
+  // maybe just shift domain_id into 32-bit or 64-bit register 
+  // and if there value of this var != 0, we are active...
+  // increment some variable, so it is possible to test leakage
+  // multiple locks or multiple unlocks
+    
+  if (stm32_rcclock_count >= 0)
+    {
+      stm32_rcclock_count++;
+      if (stm32_rcclock_count > 64)
+        {
+          stm32_rcclock_count = -1; /* capture error */
+        }
+    }
+    
+  return 0;
+}
+
+uint32_t stm32_rccunlock(uint8_t domain_id)
+{
+    if (stm32_rcclock_count > -1)
+      {
+        stm32_rcclock_count--;
+      }
+    return 0;
+}
+
+uint32_t stm32_setrccoptions(uint8_t domain_id, uint32_t options)
+{
+}
+
+int stm32_getrccactivity(void)
+{
+    return stm32_rcclock_count;
+}
+#endif
diff --git a/arch/arm/src/stm32/stm32_rcc.h b/arch/arm/src/stm32/stm32_rcc.h
index 1c0020a21d..a224447a1b 100755
--- a/arch/arm/src/stm32/stm32_rcc.h
+++ b/arch/arm/src/stm32/stm32_rcc.h
@@ -72,22 +72,21 @@ extern "C" {
 
 extern uint32_t stm32_vectors[];	/* See stm32_vectors.S */
 
-
 /************************************************************************************
  * Public Function Prototypes
  ************************************************************************************/
 
-/** Called to change to new clock based on settings in board.h
+/* Called to change to new clock based on settings in board.h
  * 
- *   NOTE:  This logic needs to be extended so that we can selected low-power
- *   clocking modes as well!
- **/
+ * NOTE:  This logic needs to be extended so that we can selected low-power
+ * clocking modes as well!
+ */
+
 EXTERN void stm32_clockconfig(void);
 
-/** Enable LSE Clock
- **/
-EXTERN void stm32_rcc_enablelse(void);
+/* Enable LSE Clock */
 
+EXTERN void stm32_rcc_enablelse(void);
 
 #undef EXTERN
 #if defined(__cplusplus)
diff --git a/arch/arm/src/stm32/stm32_sdio.c b/arch/arm/src/stm32/stm32_sdio.c
index 63930ef8bc..1bd2b8c976 100644
--- a/arch/arm/src/stm32/stm32_sdio.c
+++ b/arch/arm/src/stm32/stm32_sdio.c
@@ -317,6 +317,12 @@ static int  stm32_interrupt(int irq, void *context);
 
 /* SDIO interface methods ***************************************************/
 
+/* Mutual exclusion */
+
+#ifdef CONFIG_SDIO_MUXBUS
+static int stm32_lock(FAR struct sdio_dev_s *dev, bool lock);
+#endif
+
 /* Initialization/setup */
 
 static void stm32_reset(FAR struct sdio_dev_s *dev);
@@ -380,6 +386,9 @@ struct stm32_dev_s g_sdiodev =
 {
   .dev =
   {
+#ifdef CONFIG_SDIO_MUXBUS
+    .lock             = stm32_lock,
+#endif
     .reset            = stm32_reset,
     .status           = stm32_status,
     .widebus          = stm32_widebus,
@@ -1312,6 +1321,35 @@ static int stm32_interrupt(int irq, void *context)
 /****************************************************************************
  * SDIO Interface Methods
  ****************************************************************************/
+
+/****************************************************************************
+ * Name: stm32_lock
+ *
+ * Description:
+ *   Locks the bus. Function calls low-level multiplexed bus routines to
+ *   resolve bus requests and acknowledgment issues.
+ *
+ * Input Parameters:
+ *   dev    - An instance of the SDIO device interface
+ *   lock   - TRUE to lock, FALSE to unlock.
+ *
+ * Returned Value:
+ *   OK on success; a negated errno on failure
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_SDIO_MUXBUS
+static int stm32_lock(FAR struct sdio_dev_s *dev, bool lock)
+{  
+  /* Single SDIO instance so there is only one possibility.  The multiplex
+   * bus is part of board support package.
+   */
+
+  stm32_muxbus_sdio_lock(lock);
+  return OK;
+}
+#endif
+
 /****************************************************************************
  * Name: stm32_reset
  *
@@ -2574,8 +2612,12 @@ FAR struct sdio_dev_s *sdio_initialize(int slotno)
 
   /* Configure GPIOs for 4-bit, wide-bus operation (the chip is capable of
    * 8-bit wide bus operation but D4-D7 are not configured).
+   * 
+   * If bus is multiplexed then there is a custom bus configuration utility
+   * in the scope of the board support package.
    */
 
+#ifndef CONFIG_SDIO_MUXBUS
   stm32_configgpio(GPIO_SDIO_D0);
 #ifndef CONFIG_SDIO_WIDTH_D1_ONLY
   stm32_configgpio(GPIO_SDIO_D1);
@@ -2584,6 +2626,7 @@ FAR struct sdio_dev_s *sdio_initialize(int slotno)
 #endif
   stm32_configgpio(GPIO_SDIO_CK);
   stm32_configgpio(GPIO_SDIO_CMD);
+#endif
 
   /* Reset the card and assure that it is in the initial, unconfigured
    * state.
diff --git a/configs/README.txt b/configs/README.txt
index d90d4c655a..f958e30857 100644
--- a/configs/README.txt
+++ b/configs/README.txt
@@ -562,6 +562,7 @@ defconfig -- This is a configuration file similar to the Linux
 		  for pipe and FIFO support
 
 	Filesystem configuration
+
 		CONFIG_FS_FAT - Enable FAT filesystem support
 		CONFIG_FAT_SECTORSIZE - Max supported sector size
 		CONFIG_FAT_LCNAMES - Enable use of the NT-style upper/lower case 8.3
@@ -604,6 +605,7 @@ defconfig -- This is a configuration file similar to the Linux
 		  implemented by copying whole files into memory.
 
 	SPI driver
+
 		CONFIG_SPI_OWNBUS - Set if there is only one active device
 		  on the SPI bus.  No locking or SPI configuration will be performed.
 		  It is not necessary for clients to lock, re-configure, etc..
@@ -611,6 +613,7 @@ defconfig -- This is a configuration file similar to the Linux
 		  (vs a recvblock() and sndblock ()methods)
 
 	SPI-based MMC/SD driver
+
 		CONFIG_MMCSD_NSLOTS - Number of MMC/SD slots supported by the
 		  driver. Default is one.
 		CONFIG_MMCSD_READONLY -  Provide read-only access.  Default is
@@ -618,17 +621,24 @@ defconfig -- This is a configuration file similar to the Linux
 		CONFIG_MMCSD_SPICLOCK - Maximum SPI clock to drive MMC/SD card.
 		  Default is 20MHz.
 
-	SDIO-based MMC/SD driver
-		CONFIG_FS_READAHEAD - Enable read-ahead buffering
-		CONFIG_FS_WRITEBUFFER - Enable write buffering
+	SDIO/SDHC driver:
+
 		CONFIG_SDIO_DMA - SDIO driver supports DMA
-		CONFIG_MMCSD_MMCSUPPORT - Enable support for MMC cards
-		CONFIG_MMCSD_HAVECARDDETECT - SDIO driver card detection is
-		  100% accurate
+		CONFIG_SDIO_MUXBUS - Set this SDIO interface if the SDIO interface
+		  or hardware resources are shared with other drivers.
 		CONFIG_SDIO_WIDTH_D1_ONLY - Select 1-bit transfer mode.  Default:
 		  4-bit transfer mode.
 
+	SDIO-based MMC/SD driver
+
+		CONFIG_FS_READAHEAD - Enable read-ahead buffering
+		CONFIG_FS_WRITEBUFFER - Enable write buffering
+		CONFIG_MMCSD_MMCSUPPORT - Enable support for MMC cards
+		CONFIG_MMCSD_HAVECARDDETECT - SDIO driver card detection is
+		  100% accurate
+
 	RiT P14201 OLED driver
+
 		CONFIG_LCD_P14201 - Enable P14201 support
 		CONFIG_P14201_SPIMODE - Controls the SPI mode
 		CONFIG_P14201_FREQUENCY - Define to use a different bus frequency
@@ -683,7 +693,17 @@ defconfig -- This is a configuration file similar to the Linux
 		  there are multiple TSC2007 touchscreens, this setting will enable
 		  multiple touchscreens with the same driver.
 
+	Analog Devices
+
+		CONFIG_DAC
+		  Enables general support for Digital-to-Analog conversion devices.
+		CONFIG_ADC
+		  Enables general support for Analog-to-Digital conversion devices.
+		CONFIG_ADC_ADS125X
+		  Adds support for the TI ADS 125x ADC.
+
 	ENC28J60 Ethernet Driver Configuration Settings:
+
 		CONFIG_NET_ENC28J60 - Enabled ENC28J60 support
 		CONFIG_ENC28J60_SPIMODE - Controls the SPI mode
 		CONFIG_ENC28J60_FREQUENCY - Define to use a different bus frequency
@@ -693,6 +713,7 @@ defconfig -- This is a configuration file similar to the Linux
 		CONFIG_ENC28J60_HALFDUPPLEX - Default is full duplex
 
 	Networking support via uIP
+
 		CONFIG_NET - Enable or disable all network features
 		CONFIG_NET_NOINTS --  CONFIG_NET_NOINT indicates that uIP not called from
 		  the interrupt level.  If CONFIG_NET_NOINTS is defined, critical sections
@@ -782,10 +803,12 @@ defconfig -- This is a configuration file similar to the Linux
 		  Default: 128
 
 	UIP Network Utilities
+
 		CONFIG_NET_DHCP_LIGHT - Reduces size of DHCP
 		CONFIG_NET_RESOLV_ENTRIES - Number of resolver entries
 
-	THTTPD:
+	THTTPD
+
 		CONFIG_THTTPD_PORT - THTTPD Server port number
 		CONFIG_THTTPD_IPADDR - Server IP address (no host name)
 		CONFIG_THTTPD_SERVER_ADDRESS - SERVER_ADDRESS: response
@@ -842,6 +865,7 @@ defconfig -- This is a configuration file similar to the Linux
 		  and verify referrers.
 
 	USB device controller driver
+
 		CONFIG_USBDEV - Enables USB device support
 		CONFIG_USBDEV_ISOCHRONOUS - Build in extra support for isochronous
 		  endpoints
@@ -854,6 +878,7 @@ defconfig -- This is a configuration file similar to the Linux
 		CONFIG_USBDEV_TRACE_NRECORDS - Number of trace entries to remember
 
 	USB host controller driver
+
 	  CONFIG_USBHOST
 		Enables USB host support
 	  CONFIG_USBHOST_NPREALLOC
@@ -1073,7 +1098,9 @@ appconfig -- This is another configuration file that is specific to the
 
 setenv.sh -- This is a script that you can include that will be installed at
   the toplevel of the directory structure and can be sourced to set any
-  necessary environment variables.
+  necessary environment variables.  You will most likely have to customize the
+  default setenv.sh script in order for it to work correctly in your
+  environment.
 
 Supported Boards
 ^^^^^^^^^^^^^^^^
diff --git a/configs/vsn/README.txt b/configs/vsn/README.txt
index f76cac1d5e..9613c12ef7 100644
--- a/configs/vsn/README.txt
+++ b/configs/vsn/README.txt
@@ -3,6 +3,7 @@ README
 
 This README discusses issues unique to NuttX configurations for the
 ISOTEL NetClamps VSN V1.2 ready2go sensor network platform.
+More information can be found at http://www.netclamps.com
 
 Contents
 ^^^^^^^^
@@ -164,77 +165,6 @@ NuttX buildroot Toolchain
   detailed PLUS some special instructions that you will need to follow if you are
   building a Cortex-M3 toolchain for Cygwin under Windows.
 
-DFU
-^^^
-
-  The linker files in these projects can be configured to indicate that you
-  will be loading code using STMicro built-in USB Device Firmware Upgrade (DFU)
-  loader or via some JTAG emulator.  You can specify the DFU bootloader by
-  adding the following line:
-
-    CONFIG_STM32_DFU=y
-
-  to your .config file. Most of the configurations in this directory are set
-  up to use the DFU loader.
-
-  If CONFIG_STM32_DFU is defined, the code will not be positioned at the beginning
-  of FLASH (0x08000000) but will be offset to 0x08003000.  This offset is needed
-  to make space for the DFU loader and 0x08003000 is where the DFU loader expects
-  to find new applications at boot time.  If you need to change that origin for some
-  other bootloader, you will need to edit the file(s) ld.script.dfu for each
-  configuration.
-
-  The DFU SE PC-based software is available from the STMicro website,
-  http://www.st.com.  General usage instructions:
-  
-  1. Convert the NuttX Intel Hex file (nuttx.ihx) into a special DFU
-     file (nuttx.dfu)... see below for details.
-  2. Connect the VSN board to your computer using a USB
-     cable.
-  3. Start the DFU loader on the VSN board.  You do this by
-     resetting the board while holding the "Key" button.  Windows should
-     recognize that the DFU loader has been installed.
-  3. Run the DFU SE program to load nutt.dfu into FLASH.
-
-  What if the DFU loader is not in FLASH?  The loader code is available
-  inside of the Demo dirctory of the USBLib ZIP file that can be downloaded
-  from the STMicro Website.  You can build it using RIDE (or other toolchains);
-  you will need a JTAG emulator to burn it into FLASH the first time.
-
-  In order to use STMicro's built-in DFU loader, you will have to get
-  the NuttX binary into a special format with a .dfu extension.  The
-  DFU SE PC_based software installation includes a file "DFU File Manager"
-  conversion program that a file in Intel Hex format to the special DFU
-  format.  When you successfully build NuttX, you will find a file called
-  nutt.ihx in the top-level directory.  That is the file that you should
-  provide to the DFU File Manager.  You will need to rename it to nuttx.hex
-  in order to find it with the DFU File Manager. You will end up with
-  a file called nuttx.dfu that you can use with the STMicro DFU SE program.
-
-LEDs
-^^^^
-
-The VSN board has four LEDs labeled LD1, LD2, LD3 and LD4 on the
-the board.  Usage of these LEDs is defined in include/board.h and src/up_leds.c.
-They are encoded as follows:
-
-	SYMBOL				Meaning					LED1*	LED2	LED3	LED4
-	-------------------	-----------------------	-------	-------	-------	------
-	LED_STARTED			NuttX has been started	ON		OFF		OFF		OFF
-	LED_HEAPALLOCATE	Heap has been allocated	OFF		ON		OFF		OFF
-	LED_IRQSENABLED		Interrupts enabled		ON		ON		OFF		OFF
-	LED_STACKCREATED	Idle stack created		OFF		OFF		ON		OFF
-	LED_INIRQ			In an interrupt**		ON		N/C		N/C		OFF
-	LED_SIGNAL			In a signal handler***  N/C		ON		N/C		OFF
-	LED_ASSERTION		An assertion failed		ON		ON		N/C		OFF
-	LED_PANIC			The system has crashed	N/C		N/C		N/C		ON
-
-  * If LED1, LED2, LED3 are statically on, then NuttX probably failed to boot
-    and these LEDs will give you some indication of where the failure was
- ** The normal state is LED3 ON and LED1 faintly glowing.  This faint glow
-    is because of timer interupts that result in the LED being illuminated
-    on a small proportion of the time.
-*** LED2 may also flicker normally if signals are processed.
 
 VSN-specific Configuration Options
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -259,7 +189,7 @@ VSN-specific Configuration Options
 	CONFIG_ARCH_CHIP_name - For use in C code to identify the exact
 	   chip:
 
-	   CONFIG_ARCH_CHIP_STM32F103ZET6
+	   CONFIG_ARCH_CHIP_STM32F103RET6
 
 	CONFIG_ARCH_BOARD - Identifies the configs subdirectory and
 	   hence, the board that supports the particular chip or SoC.
@@ -292,9 +222,6 @@ VSN-specific Configuration Options
 
 	   CONFIG_ARCH_IRQPRIO=y
 
-	CONFIG_ARCH_LEDS - Use LEDs to show state. Unique to boards that
-	   have LEDs
-
 	CONFIG_ARCH_INTERRUPTSTACK - This architecture supports an interrupt
 	   stack. If defined, this symbol is the size of the interrupt
 	    stack in bytes.  If not defined, the user task stacks will be
@@ -311,96 +238,6 @@ VSN-specific Configuration Options
 	   the 100 second delay then adjust CONFIG_ARCH_LOOPSPERMSEC until
 	   the delay actually is 100 seconds.
 
-  Individual subsystems can be enabled:
-	AHB
-	---
-	CONFIG_STM32_DMA1
-	CONFIG_STM32_DMA2
-	CONFIG_STM32_CRC
-	CONFIG_STM32_FSMC
-	CONFIG_STM32_SDIO
-
-	APB1
-	----
-	CONFIG_STM32_TIM2
-	CONFIG_STM32_TIM3
-	CONFIG_STM32_TIM4
-	CONFIG_STM32_TIM5
-	CONFIG_STM32_TIM6
-	CONFIG_STM32_TIM7
-	CONFIG_STM32_WWDG
-	CONFIG_STM32_SPI2
-	CONFIG_STM32_SPI4
-	CONFIG_STM32_USART2
-	CONFIG_STM32_USART3
-	CONFIG_STM32_UART4
-	CONFIG_STM32_UART5
-	CONFIG_STM32_I2C1
-	CONFIG_STM32_I2C2
-	CONFIG_STM32_USB
-	CONFIG_STM32_CAN
-	CONFIG_STM32_BKP
-	CONFIG_STM32_PWR
-	CONFIG_STM32_DAC
-	CONFIG_STM32_USB
-
-	APB2
-	----
-	CONFIG_STM32_ADC1
-	CONFIG_STM32_ADC2
-	CONFIG_STM32_TIM1
-	CONFIG_STM32_SPI1
-	CONFIG_STM32_TIM8
-	CONFIG_STM32_USART1
-	CONFIG_STM32_ADC3
-
-  Alternate pin mappings (should not be used with the VSN board):
-
-	CONFIG_STM32_TIM1_FULL_REMAP
-	CONFIG_STM32_TIM1_PARTIAL_REMAP
-	CONFIG_STM32_TIM2_FULL_REMAP
-	CONFIG_STM32_TIM2_PARTIAL_REMAP_1
-	CONFIG_STM32_TIM2_PARTIAL_REMAP_2
-	CONFIG_STM32_TIM3_FULL_REMAP
-	CONFIG_STM32_TIM3_PARTIAL_REMAP
-	CONFIG_STM32_TIM4_REMAP
-	CONFIG_STM32_USART1_REMAP
-	CONFIG_STM32_USART2_REMAP
-	CONFIG_STM32_USART3_FULL_REMAP
-	CONFIG_STM32_USART3_PARTIAL_REMAP
-	CONFIG_STM32_SPI1_REMAP
-	CONFIG_STM32_SPI3_REMAP
-	CONFIG_STM32_I2C1_REMAP
-	CONFIG_STM32_CAN1_FULL_REMAP
-	CONFIG_STM32_CAN1_PARTIAL_REMAP
-	CONFIG_STM32_CAN2_REMAP
-
-  STM32F103Z specific device driver settings
-
-	CONFIG_U[S]ARTn_SERIAL_CONSOLE - selects the USARTn (n=1,2,3) or UART
-           m (m=4,5) for the console and ttys0 (default is the USART1).
-	CONFIG_U[S]ARTn_RXBUFSIZE - Characters are buffered as received.
-	   This specific the size of the receive buffer
-	CONFIG_U[S]ARTn_TXBUFSIZE - Characters are buffered before
-	   being sent.  This specific the size of the transmit buffer
-	CONFIG_U[S]ARTn_BAUD - The configure BAUD of the UART.  Must be
-	CONFIG_U[S]ARTn_BITS - The number of bits.  Must be either 7 or 8.
-	CONFIG_U[S]ARTn_PARTIY - 0=no parity, 1=odd parity, 2=even parity
-	CONFIG_U[S]ARTn_2STOP - Two stop bits
-
-	CONFIG_STM32_SPI_INTERRUPTS - Select to enable interrupt driven SPI
-	  support. Non-interrupt-driven, poll-waiting is recommended if the
-	  interrupt rate would be to high in the interrupt driven case.
-	CONFIG_STM32_SPI_DMA - Use DMA to improve SPI transfer performance.
-	  Cannot be used with CONFIG_STM32_SPI_INTERRUPT.
-
-	CONFIG_SDIO_DMA - Support DMA data transfers.  Requires CONFIG_STM32_SDIO
-	  and CONFIG_STM32_DMA2.
-	CONFIG_SDIO_PRI - Select SDIO interrupt prority.  Default: 128
-	CONFIG_SDIO_DMAPRIO - Select SDIO DMA interrupt priority. 
-	  Default:  Medium
-	CONFIG_SDIO_WIDTH_D1_ONLY - Select 1-bit transfer mode.  Default:
-	  4-bit transfer mode.
 
 Configurations
 ^^^^^^^^^^^^^^
@@ -418,3 +255,7 @@ Where <subdir> is one of the following:
   nsh:
     Configures the NuttShell (nsh) located at examples/nsh.  The
     Configuration enables both the serial and telnetd NSH interfaces.
+
+The default configuration sets up a console on front-panel RS-232 
+interface, sets up device driver of all supported equipment and 
+links in VSN default applications.
diff --git a/configs/vsn/include/board.h b/configs/vsn/include/board.h
index a1a30c4b19..9f7ec07565 100644
--- a/configs/vsn/include/board.h
+++ b/configs/vsn/include/board.h
@@ -52,6 +52,9 @@
 #include "stm32_sdio.h"
 #include "stm32_internal.h"
 
+#include "muxbus.h"
+
+
 /************************************************************************************
  * Definitions
  ************************************************************************************/
diff --git a/configs/vsn/include/muxbus.h b/configs/vsn/include/muxbus.h
new file mode 100644
index 0000000000..595ded46ff
--- /dev/null
+++ b/configs/vsn/include/muxbus.h
@@ -0,0 +1,84 @@
+/************************************************************************************
+ * configs/vsn/include/muxbus.h
+ * include/arch/board/muxbus.h
+ *
+ *   Copyright (C) 2011 Uros Platise. All rights reserved
+ * 
+ *   Authors: Uros Platise <uros.platise@isotel.eu>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ************************************************************************************/
+
+#ifndef __ARCH_BOARD_MUXBUS_H
+#define __ARCH_BOARD_MUXBUS_H
+
+#ifndef __ASSEMBLY__
+#undef EXTERN
+#if defined(__cplusplus)
+#define EXTERN extern "C"
+extern "C" {
+#else
+#define EXTERN extern
+#endif
+
+/************************************************************************************
+ * Public Functions
+ ************************************************************************************/
+
+/**
+ * Initialization of the semaphore and initial bus state.
+ */
+void vsn_muxbus_init(void);
+
+/** 
+ * Simple Lock / Unlock Mechanism for the SDIO Interface
+ * 
+ * NOTE: This function is provided for the stm32_sdio driver.
+ */
+extern void stm32_muxbus_sdio_lock(bool lock);
+
+/**
+ * Set PGA Gain of the Analog Devices AD8231 on bus shared with the 
+ * SDIO interface
+ * 
+ * \param gain sets the front-end gain as 2^{gain}, where gain = 0..7.
+ *   Setting gain outside that range shutdowns the front-end.
+ * 
+ * \return gain set or -1 if front end is put into shutdown.
+ */
+extern int vsn_muxbus_setpgagain(int gain);
+
+
+#undef EXTERN
+#if defined(__cplusplus)
+}
+#endif
+
+#endif /* __ASSEMBLY__ */
+#endif  /* __ARCH_BOARD_MUXBUS_H */
diff --git a/configs/vsn/src/Makefile b/configs/vsn/src/Makefile
index 89ff9b8388..ec360f8f66 100644
--- a/configs/vsn/src/Makefile
+++ b/configs/vsn/src/Makefile
@@ -53,7 +53,7 @@ ASRCS		=
 AOBJS		= $(ASRCS:.S=$(OBJEXT))
 
 CSRCS		= sysclock.c boot.c leds.c buttons.c spi.c \
-			  usbdev.c power.c sif.c
+			  usbdev.c power.c muxbus.c sif.c
 
 ifeq ($(CONFIG_USBSTRG),y)
 CSRCS		+= usbstrg.c
diff --git a/configs/vsn/src/boot.c b/configs/vsn/src/boot.c
index 501bb07b5a..846f707b76 100644
--- a/configs/vsn/src/boot.c
+++ b/configs/vsn/src/boot.c
@@ -63,6 +63,7 @@ void stm32_boardinitialize(void)
   /* Set start-up board voltage */
 
   board_power_init();
+  vsn_muxbus_init();
 
   /* Configure SPI chip selects if 1) SPI is not disabled, and 2) the weak function
    * stm32_spiinitialize() has been brought into the link.
diff --git a/configs/vsn/src/muxbus.c b/configs/vsn/src/muxbus.c
new file mode 100644
index 0000000000..76304d67d2
--- /dev/null
+++ b/configs/vsn/src/muxbus.c
@@ -0,0 +1,198 @@
+/****************************************************************************
+ * config/vsn/src/muxbus.c
+ * arch/arm/src/board/muxbus.c
+ *
+ *   Copyright (C) 2011 Uros Platise. All rights reserved.
+ *
+ *   Authors: Uros Platise <uros.platise@isotel.eu>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/** \file
+ *  \author Uros Platise
+ *  \brief VSN Multiplexed Bus, SDIO Interface and the Analog Front-End
+ */
+
+#include <nuttx/config.h>
+#include <semaphore.h>
+#include <errno.h>
+
+#include "vsn.h"
+#include "stm32_gpio.h"
+
+
+/****************************************************************************
+ * Private data
+ ****************************************************************************/
+
+/** Set true when the bus has been locked by the SDIO interface */
+bool vsn_muxbus_ownedbysdio;
+
+/** Semaphore to resolve conflicts between muxbus locks */
+sem_t vsn_muxbus_sem;
+
+
+/****************************************************************************
+ * Private functions
+ ****************************************************************************/
+
+void vsn_muxbus_takeownership(void)
+{
+    while (sem_wait(&vsn_muxbus_sem) != 0) {
+    
+        /* The only case that an error should occr here is if the wait was
+         * awakened by a signal.
+         */
+
+        ASSERT(errno == EINTR);
+    }
+}
+
+
+void vsn_muxbus_sdio_release(void)
+{
+    stm32_unconfiggpio(GPIO_SDIO_D0);
+    stm32_unconfiggpio(GPIO_SDIO_CK);
+    stm32_unconfiggpio(GPIO_SDIO_CMD);
+    
+    vsn_muxbus_ownedbysdio = FALSE;
+}
+
+
+void vsn_muxbus_sdio_access(void)
+{
+    stm32_configgpio(GPIO_SDIO_D0);
+    stm32_configgpio(GPIO_SDIO_CK);
+    stm32_configgpio(GPIO_SDIO_CMD);
+
+    vsn_muxbus_ownedbysdio = TRUE;
+}
+
+
+/****************************************************************************
+ * Public functions
+ ****************************************************************************/
+
+
+void vsn_muxbus_init(void)
+{
+    /* Put the PGA in default shut-down state */
+
+    stm32_configgpio(GPIO_PGIA_AEN);
+
+    /* setup semaphore in non-locked condition */
+    
+    sem_init(&vsn_muxbus_sem, 0, 1);
+    
+    /* by default give the bus to the SDIO */
+    
+    vsn_muxbus_sdio_access();
+}
+
+
+/** 
+ * We could do extra checks: who is the owner to prevent
+ * unlocking from SDIO side eventhough it was not locked 
+ * by him, but temporarily by the PGA
+ */
+void stm32_muxbus_sdio_lock(bool lock)
+{
+    if ( lock )
+        vsn_muxbus_takeownership();
+    else
+        sem_post(&vsn_muxbus_sem);
+}
+
+
+/**
+ * The following rules apply for the SDcard:
+ * 
+ *  - CMD serial line always starts with 0 (start-bit) and ends with 1 (stop-bit)
+ *    The total length is always 48 bits protected by CRCs. When changing the 
+ *    gain, CMD must be seen as 1 on CK changes.
+ * 
+ *  - An alternative mechanism would be to use suspend/resume commands
+ * 
+ *  - If SDcard internal shift-register is 8-bit oriented there might be a need
+ *    to shift 7 dummy bits to properly detect invalid start of packet 
+ *    (with start bit set as 1) to invalidate bus transitions (in case CK 
+ *    is changing).
+ * 
+ * SDIO returns the bus in HiZ states, where CLK = 0, D = CMD = external pull-up
+ */
+int vsn_muxbus_setpgagain(int gain)
+{
+    /* Shutdown the Analog Devices AD8231 and exit if gain is invalid */
+
+    stm32_gpiowrite(GPIO_PGIA_AEN, FALSE);
+    
+    if (gain < 0 || gain > 7)
+        return -1;
+
+    vsn_muxbus_takeownership();
+    vsn_muxbus_sdio_release();
+    
+    /* If we have to set CLK = 1, made that first as D, CMD are 1 by pull-ups */
+    
+    if (gain & 2)
+        stm32_configgpio(GPIO_PGIA_A1_H);
+    else stm32_configgpio(GPIO_PGIA_A1_L);
+    
+    /* Set the D and CMD bits */
+    
+    if (gain & 1)
+        stm32_configgpio(GPIO_PGIA_A0_H);
+    else stm32_configgpio(GPIO_PGIA_A0_L);
+        
+    if (gain & 4)
+        stm32_configgpio(GPIO_PGIA_A2_H);
+    else stm32_configgpio(GPIO_PGIA_A2_L);
+    
+    /* Sample GAIN on rising edge */
+    
+    stm32_gpiowrite(GPIO_PGIA_AEN, TRUE);
+    
+    /* Release D and CMD pins to 1; however shorten rising edge actively */
+    
+    stm32_gpiowrite(GPIO_PGIA_A0_H, TRUE);
+    stm32_gpiowrite(GPIO_PGIA_A2_H, TRUE);
+    
+    stm32_unconfiggpio(GPIO_PGIA_A0_H);
+    stm32_unconfiggpio(GPIO_PGIA_A2_H);
+    
+    /* Release CLK by going down and return the bus */
+    
+    stm32_unconfiggpio(GPIO_PGIA_A1_L);    
+    
+    vsn_muxbus_sdio_access();
+    sem_post(&vsn_muxbus_sem);
+    
+    return gain;
+}
diff --git a/configs/vsn/src/sif.c b/configs/vsn/src/sif.c
index 0e08280dec..535a09829a 100644
--- a/configs/vsn/src/sif.c
+++ b/configs/vsn/src/sif.c
@@ -313,12 +313,12 @@ int sif_anout_init(void)
     
     // Use the TIM3 as PWM modulated analogue output
     
-    STM32_TIM_SETPERIOD(vsn_sif.tim3, 4096);
-    STM32_TIM_SETCOMPARE(vsn_sif.tim3, GPIO_OUT_PWM_TIM3_CH, 1024);
+    STM32_TIM_SETPERIOD(vsn_sif.tim3, 5);
+    STM32_TIM_SETCOMPARE(vsn_sif.tim3, GPIO_OUT_PWM_TIM3_CH, 3);
 
     STM32_TIM_SETCLOCK(vsn_sif.tim3, 36e6);
     STM32_TIM_SETMODE(vsn_sif.tim3, STM32_TIM_MODE_UP);
-    //STM32_TIM_SETCHANNEL(vsn_sif.tim3, GPIO_OUT_PWM_TIM3_CH, STM32_TIM_CH_OUTPWM | STM32_TIM_CH_POLARITY_NEG);
+    STM32_TIM_SETCHANNEL(vsn_sif.tim3, GPIO_OUT_PWM_TIM3_CH, STM32_TIM_CH_OUTPWM | STM32_TIM_CH_POLARITY_NEG);
     
     // Use the TIM8 to drive the upper power mosfet
     
@@ -330,7 +330,7 @@ int sif_anout_init(void)
     
     STM32_TIM_SETCLOCK(vsn_sif.tim8, 36e6);
     STM32_TIM_SETMODE(vsn_sif.tim8, STM32_TIM_MODE_UP);
-    STM32_TIM_SETCHANNEL(vsn_sif.tim8, GPIO_OUT_PWRPWM_TIM8_CH, STM32_TIM_CH_OUTPWM | STM32_TIM_CH_POLARITY_NEG);
+    //STM32_TIM_SETCHANNEL(vsn_sif.tim8, GPIO_OUT_PWRPWM_TIM8_CH, STM32_TIM_CH_OUTPWM | STM32_TIM_CH_POLARITY_NEG);
 
     vsn_sif.i2c1 = up_i2cinitialize(1);
     vsn_sif.i2c2 = up_i2cinitialize(2);
@@ -366,9 +366,77 @@ void sif_anref_init(void)
  * Analog Input Sampler Unit
  ****************************************************************************/ 
 
-
-void sif_anin_reset(void)
+#if 0
+/**
+ * Gain is set using the shared multiplexed bus with the SDIO card.
+ * The following rules apply for the SDcard:
+ * 
+ *  - CMD serial line always starts with 0 (start-bit) and ends with 1 (stop-bit)
+ *    The total length is always 48 bits protected by CRCs. When changing the 
+ *    gain, CMD must be seen as 1 on CK changes.
+ * 
+ *  - An alternative mechanism would be to use suspend/resume commands
+ * 
+ *  - If SDcard internal shift-register is 8-bit oriented there might be a need
+ *    to shift 7 dummy bits to properly detect invalid start of packet 
+ *    (with start bit set as 1) to invalidate bus transitions (in case CK 
+ *    is changing).
+ * 
+ * SDIO returns the bus in HiZ states, where CLK = 0, D = CMD = external pull-up
+ */
+int sif_anin_setgain(int gain)
 {
+    /* Shutdown the PGA and exit if gain is invalid */
+
+    stm32_gpiowrite(GPIO_PGIA_AEN, FALSE);
+    
+    if (gain < 0 || gain > 7)
+        return -1;
+    
+    sdio_gpio_request();
+    
+    /* If we have to set CLK = 1, made that first as D, CMD are 1 by pull-ups */
+    
+    if (gain & 2)
+        stm32_configgpio(GPIO_PGIA_A1_H);
+    else stm32_configgpio(GPIO_PGIA_A1_L);
+    
+    /* Set the D and CMD bits */
+    
+    if (gain & 1)
+        stm32_configgpio(GPIO_PGIA_A0_H);
+    else stm32_configgpio(GPIO_PGIA_A0_L);
+        
+    if (gain & 4)
+        stm32_configgpio(GPIO_PGIA_A2_H);
+    else stm32_configgpio(GPIO_PGIA_A2_L);
+    
+    /* Sample GAIN on rising edge */
+    
+    stm32_gpiowrite(GPIO_PGIA_AEN, TRUE);
+    
+    /* Release D and CMD pins to 1; however shorten rising edge actively */
+    
+    stm32_gpiowrite(GPIO_PGIA_A0_H, TRUE);
+    stm32_gpiowrite(GPIO_PGIA_A2_H, TRUE);
+    
+    stm32_unconfiggpio(GPIO_PGIA_A0_H);
+    stm32_unconfiggpio(GPIO_PGIA_A2_H);
+    
+    /* Release CLK by going down  */
+    
+    stm32_unconfiggpio(GPIO_PGIA_A1_L);    
+    
+    sdio_gpio_release();
+    
+    return gain;
+}
+#endif
+
+
+int sif_anin_reset(void)
+{
+    return OK;
 }
 
 
@@ -483,6 +551,7 @@ int sif_init(void)
     
     sif_gpios_reset();
     if ( sif_anout_init() != OK ) return -1;
+    if ( sif_anin_reset() != OK ) return -1;
 
     /* If everything is okay, register the driver */
     
@@ -514,7 +583,8 @@ int sif_main(int argc, char *argv[])
         }
         else if (!strcmp(argv[1], "pwr") && argc == 3) {
             int val = atoi(argv[2]);
-            STM32_TIM_SETCOMPARE(vsn_sif.tim8, GPIO_OUT_PWRPWM_TIM8_CH, val);
+            //STM32_TIM_SETCOMPARE(vsn_sif.tim8, GPIO_OUT_PWRPWM_TIM8_CH, val);
+            STM32_TIM_SETCOMPARE(vsn_sif.tim3, GPIO_OUT_PWM_TIM3_CH, val);
             return 0;
         }
         else if (!strcmp(argv[1], "time") && argc == 3) {
@@ -592,6 +662,14 @@ int sif_main(int argc, char *argv[])
 
             return 0;
         }
+        else if (!strcmp(argv[1], "pga")) {
+            int gain = atoi(argv[2]);
+            
+            gain = vsn_muxbus_setpgagain(gain);
+
+            printf("Gain changed: %d\n", gain);
+            return 0;
+        }
         else if (!strcmp(argv[1], "cc")) {
             struct cc1101_dev_s * cc;
             uint8_t buf[64];
diff --git a/configs/vsn/src/vsn.h b/configs/vsn/src/vsn.h
index 0b1d5dbc33..eb999f2466 100644
--- a/configs/vsn/src/vsn.h
+++ b/configs/vsn/src/vsn.h
@@ -150,6 +150,14 @@
 #define GPIO_OUT_PWM	(GPIO_ALT   |GPIO_CNF_AFPP     |GPIO_MODE_10MHz|GPIO_PORTB|GPIO_PIN1 )
 #define GPIO_OUT_PWM_TIM3_CH        4   /* TIM3.CH4 */ 
 
+#define GPIO_PGIA_A0_H  (GPIO_OUTPUT|GPIO_CNF_OUTPP    |GPIO_MODE_2MHz |GPIO_PORTC|GPIO_PIN8 |GPIO_OUTPUT_SET)
+#define GPIO_PGIA_A0_L  (GPIO_OUTPUT|GPIO_CNF_OUTPP    |GPIO_MODE_2MHz |GPIO_PORTC|GPIO_PIN8 |GPIO_OUTPUT_CLEAR)
+#define GPIO_PGIA_A1_L  (GPIO_OUTPUT|GPIO_CNF_OUTPP    |GPIO_MODE_2MHz |GPIO_PORTC|GPIO_PIN12|GPIO_OUTPUT_CLEAR)
+#define GPIO_PGIA_A1_H  (GPIO_OUTPUT|GPIO_CNF_OUTPP    |GPIO_MODE_2MHz |GPIO_PORTC|GPIO_PIN12|GPIO_OUTPUT_SET)
+#define GPIO_PGIA_A2_H  (GPIO_OUTPUT|GPIO_CNF_OUTPP    |GPIO_MODE_2MHz |GPIO_PORTD|GPIO_PIN2 |GPIO_OUTPUT_SET)
+#define GPIO_PGIA_A2_L  (GPIO_OUTPUT|GPIO_CNF_OUTPP    |GPIO_MODE_2MHz |GPIO_PORTD|GPIO_PIN2 |GPIO_OUTPUT_CLEAR)
+#define GPIO_PGIA_AEN   (GPIO_OUTPUT|GPIO_CNF_OUTPP    |GPIO_MODE_2MHz |GPIO_PORTC|GPIO_PIN1 |GPIO_OUTPUT_CLEAR)
+
 
 /* Radio Connector */
 
diff --git a/drivers/mmcsd/mmcsd_sdio.c b/drivers/mmcsd/mmcsd_sdio.c
index 1434c440c6..27232983ef 100644
--- a/drivers/mmcsd/mmcsd_sdio.c
+++ b/drivers/mmcsd/mmcsd_sdio.c
@@ -148,7 +148,10 @@ struct mmcsd_state_s
 /* Misc Helpers *************************************************************/
 
 static void    mmcsd_takesem(FAR struct mmcsd_state_s *priv);
-#define mmcsd_givesem(p) sem_post(&priv->sem);
+
+#ifndef CONFIG_SDIO_MUXBUS
+#  define mmcsd_givesem(p) sem_post(&priv->sem);
+#endif
 
 /* Command/response helpers *************************************************/
 
@@ -261,18 +264,41 @@ static const struct block_operations g_bops =
 
 static void mmcsd_takesem(FAR struct mmcsd_state_s *priv)
 {
-  /* Take the semaphore (perhaps waiting) */
+  /* Take the semaphore, giving exclusive access to the driver (perhaps
+   * waiting)
+   */
 
   while (sem_wait(&priv->sem) != 0)
     {
-      /* The only case that an error should occr here is if the wait was
+      /* The only case that an error should occur here is if the wait was
        * awakened by a signal.
        */
 
       ASSERT(errno == EINTR);
     }
+
+  /* Lock the bus if mutually exclusive access to the SDIO bus is required
+   * on this platform.
+   */
+  
+#ifdef CONFIG_SDIO_MUXBUS
+  SDIO_LOCK(priv->dev, TRUE);
+#endif
 }
 
+#ifdef CONFIG_SDIO_MUXBUS
+static void mmcsd_givesem(FAR struct mmcsd_state_s *priv)
+{
+  /* Release the SDIO bus lock, then the MMC/SD driver semaphore in the
+   * opposite order that they were taken to assure that no deadlock
+   * conditions will arise.
+   */
+
+  SDIO_LOCK(priv->dev, FALSE);
+  sem_post(&priv->sem);
+}
+#endif
+
 /****************************************************************************
  * Command/Response Helpers
  ****************************************************************************/
diff --git a/drivers/wireless/cc1101/cc1101.c b/drivers/wireless/cc1101/cc1101.c
index e2fae96203..a355756903 100755
--- a/drivers/wireless/cc1101/cc1101.c
+++ b/drivers/wireless/cc1101/cc1101.c
@@ -55,6 +55,45 @@
  *   - Power up/down modes
  *   - Sequencing between states or add protection for correct termination of
  *     various different state (so that CC1101 does not block in case of improper use)
+ * 
+ * \par RSSI and LQI value interpretation
+ * 
+ * The LQI can be read from the LQI status register or it can be appended 
+ * to the received packet in the RX FIFO. LQI is a metric of the current 
+ * quality of the received signal. The LQI gives an estimate of how easily 
+ * a received signal can be demodulated by accumulating the magnitude of 
+ * the error between ideal constellations and the received signal over 
+ * the 64 symbols immediately following the sync word. LQI is best used 
+ * as a relative measurement of the link quality (a high value indicates 
+ * a better link than what a low value does), since the value is dependent 
+ * on the modulation format.
+ * 
+ * To simplify: If the received modulation is FSK or GFSK, the receiver 
+ * will measure the frequency of each "bit" and compare it with the 
+ * expected frequency based on the channel frequency and the deviation 
+ * and the measured frequency offset. If other modulations are used, the 
+ * error of the modulated parameter (frequency for FSK/GFSK, phase for 
+ * MSK, amplitude for ASK etc) will be measured against the expected 
+ * ideal value
+ * 
+ * RSSI (Received Signal Strength Indicator) is a signal strength 
+ * indication. It does not care about the "quality" or "correctness" of 
+ * the signal. LQI does not care about the actual signal strength, but 
+ * the signal quality often is linked to signal strength. This is because 
+ * a strong signal is likely to be less affected by noise and thus will 
+ * be seen as "cleaner" or more "correct" by the receiver.
+ * 
+ * There are four to five "extreme cases" that can be used to illustrate 
+ * how RSSI and LQI work:
+ *  1. A weak signal in the presence of noise may give low RSSI and low LQI.
+ *  2. A weak signal in "total" absence of noise may give low RSSI and high LQI.
+ *  3. Strong noise (usually coming from an interferer) may give high RSSI and low LQI.
+ *  4. A strong signal without much noise may give high RSSI and high LQI.
+ *  5. A very strong signal that causes the receiver to saturate may give 
+ *     high RSSI and low LQI.
+ * 
+ * Note that both RSSI and LQI are best used as relative measurements since 
+ * the values are dependent on the modulation format.
  **/ 
  
 #include <nuttx/config.h>
diff --git a/include/nuttx/sdio.h b/include/nuttx/sdio.h
index 232cdb3f3e..d1642b62c6 100644
--- a/include/nuttx/sdio.h
+++ b/include/nuttx/sdio.h
@@ -310,6 +310,24 @@
 #define SDIO_ACMD52     (SDIO_ACMDIDX52|MMCSD_R5_RESPONSE |MMCSD_NODATAXFR)
 #define SDIO_ACMD53     (SDIO_ACMDIDX53|MMCSD_R5_RESPONSE |MMCSD_NODATAXFR)
 
+/****************************************************************************
+ * Name: SDIO_LOCK
+ *
+ * Description:
+ *   Lock/unlock the SDIO bus, preventing it from any other transaction
+ *   while locked.
+ *
+ * Input Parameters:
+ *   dev      - An instance of the SDIO device interface
+ *   state    - TRUE/FALSE
+ *
+ * Returned Value:
+ *   OK on success.
+ *
+ ****************************************************************************/
+
+#define SDIO_LOCK(dev,state)  ((dev)->lock(dev,state))
+
 /****************************************************************************
  * Name: SDIO_RESET
  *
@@ -756,6 +774,12 @@ struct sdio_dev_s
    * above.
    */
 
+  /* Mutual exclusion */
+
+#ifdef CONFIG_SDIO_MUXBUS
+  int   (*lock)(FAR struct sdio_dev_s *dev, bool lock);
+#endif
+
   /* Initialization/setup */
 
   void  (*reset)(FAR struct sdio_dev_s *dev);