From 73727ef887f6c3817d025d762c7e7e396e19116d Mon Sep 17 00:00:00 2001
From: patacongo <patacongo@42af7a65-404d-4744-a932-0658087f49c3>
Date: Tue, 29 Sep 2009 18:56:20 +0000
Subject: [PATCH] Fix PU/PD config; improve MODE/CNF setting

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@2106 42af7a65-404d-4744-a932-0658087f49c3
---
 arch/arm/src/stm32/stm32_gpio.c | 33 ++++++++++++++++++++++-----------
 arch/arm/src/stm32/stm32_gpio.h |  9 ++++++---
 2 files changed, 28 insertions(+), 14 deletions(-)

diff --git a/arch/arm/src/stm32/stm32_gpio.c b/arch/arm/src/stm32/stm32_gpio.c
index a806baeed5..e805191d3c 100755
--- a/arch/arm/src/stm32/stm32_gpio.c
+++ b/arch/arm/src/stm32/stm32_gpio.c
@@ -107,8 +107,7 @@ int stm32_configgpio(uint32 cfgset)
   unsigned int gpio;
   unsigned int pin;
   unsigned int pos;
-  unsigned int mode;
-  unsigned int cnf;
+  unsigned int modecnf;
   boolean output;
  
   /* Verify that this hardware supports the select GPIO port */
@@ -142,28 +141,29 @@ int stm32_configgpio(uint32 cfgset)
 
       if (output)
         {
-          mode = (cfgset & GPIO_MODE_MASK) >> GPIO_MODE_SHIFT;
+          modecnf = (cfgset & GPIO_MODE_MASK) >> GPIO_MODE_SHIFT;
         }
       else
         {
-          mode = 0;
+          modecnf = 0;
         }
 
-      cnf = (cfgset & GPIO_CNF_MASK) >> GPIO_CNF_SHIFT;
+      modecnf |= ((cfgset & GPIO_CNF_MASK) >> GPIO_CNF_SHIFT) << 2;
      
       /* Set the port configuration register */
 
       regval = getreg32(cr);
-      regval &= ~(GPIO_CR_MODE_MASK(pos)|GPIO_CRL_CNF_MASK(pos));
-      regval |= (mode << GPIO_CR_MODE_SHIFT(pos)) | (cnf << GPIO_CRL_CNF_SHIFT(pos));
+      regval &= ~(GPIO_CR_MODECNF_MASK(pos));
+      regval |= (modecnf << GPIO_CR_MODECNF_SHIFT(pos));
       putreg32(regval, cr);
 
       /* Set or reset the corresponding BRR/BSRR bit */
 
       if (output)
         {
-	        /* It is an output pin, we need to set/clear the output value */
-
+	        /* It is an output pin, we need to instantiate the initial
+	         * pin output value
+	         */
 
 	        if ((cfgset & GPIO_OUTPUT_VALUE) != 0)
 	          {
@@ -180,16 +180,27 @@ int stm32_configgpio(uint32 cfgset)
         }
       else
         {
-          if ((cfgset & GPIO_MODE_MASK) == GPIO_CNF_INPULLDWN)
+          /* It is an input pin... If it is pull-down or pull up,
+           * then we need to set the ODR appropriately for that
+           * function.
+           */
+        
+          if ((cfgset & GPIO_MODE_MASK) == GPIO_CNF_INPULLUP)
             {
+              /* Set the ODR bit (using BSRR) to one for the PULL-UP functionality */
+            
 	          regaddr = gpiobase + STM32_GPIO_BSRR_OFFSET;
             }
-          else if ((cfgset & GPIO_MODE_MASK) == GPIO_CNF_INPULLUP)
+          else if ((cfgset & GPIO_MODE_MASK) == GPIO_CNF_INPULLDWN)
             {
+              /* Clear the ODR bit (using BRR) to zero for the PULL-DOWN functionality */
+
 	          regaddr = gpiobase + STM32_GPIO_BRR_OFFSET;
             }
             else
             {
+              /* Neither... we can return early */
+
               return OK;
             }
         }
diff --git a/arch/arm/src/stm32/stm32_gpio.h b/arch/arm/src/stm32/stm32_gpio.h
index 4e2c9f8acb..dc555b9ed4 100644
--- a/arch/arm/src/stm32/stm32_gpio.h
+++ b/arch/arm/src/stm32/stm32_gpio.h
@@ -148,10 +148,13 @@
 
 /* Port configuration register low */
 
-#define GPIO_CR_MODE_SHIFT(n)        ((n) << 1)
+#define GPIO_CR_MODE_SHIFT(n)        ((n) << 2)
 #define GPIO_CR_MODE_MASK(n)         (3 << GPIO_CR_MODE_SHIFT(n))
-#define GPIO_CRL_CNF_SHIFT(n)        (2+((n) << 1))
-#define GPIO_CRL_CNF_MASK(n)         (3 << GPIO_CRL_CNF_SHIFT(n))
+#define GPIO_CR_CNF_SHIFT(n)         (2 + ((n) << 2))
+#define GPIO_CR_CNF_MASK(n)          (3 << GPIO_CRL_CNF_SHIFT(n))
+
+#define GPIO_CR_MODECNF_SHIFT(n)     ((n) << 2)
+#define GPIO_CR_MODECNF_MASK(n)      (0x0f << GPIO_CR_MODECNF_SHIFT(n))
 
 #define GPIO_CRL_MODE0_SHIFT         (0)     /* Bits 1:0: Port mode bits */
 #define GPIO_CRL_MODE0_MASK          (3 << GPIO_CRL_MODE0_SHIFT)