LPC17xx CAN PCLK divisor is not a configuration parameter

git-svn-id: https://nuttx.svn.sourceforge.net/svnroot/nuttx/trunk@4268 7fd9a85b-ad96-42d3-883c-3090e2eb8679

nuttx/ChangeLog

@@ -2348,3 +2348,5 @@
 	  LEDs
 	* arch/arm/src/lpc17xx/lpc17_can.c: Add logic to change the CAN bit rate based
 	  on the NuttX configuration.
+	* arch/arm/src/lpc17xx/lpc17_can.c: PCLK divisor is now a configuration
+	  option.

nuttx/arch/arm/src/lpc17xx/lpc17_can.c

@@ -72,6 +72,66 @@
 /****************************************************************************
  * Pre-processor Definitions
  ****************************************************************************/
+/* Configuration ************************************************************/
+
+#ifdef CONFIG_LPC17_CAN1
+
+   /* A CAN bit rate must be provided */
+
+#  ifndef CONFIG_CAN1_BAUD
+#    error "CONFIG_CAN1_BAUD is not defined"
+#  endif
+
+   /* If no divsor is provided, use a divisor of 4 */
+
+#  ifndef CONFIG_CAN1_DIVISOR
+#    define CONFIG_CAN1_DIVISOR 4
+#  endif
+
+   /* Get the SYSCON_PCLKSEL value for CAN1 the implements this divisor */
+
+#  if CONFIG_CAN1_DIVISOR == 1
+#    define CAN1_CCLK_DIVISOR SYSCON_PCLKSEL_CCLK
+#  elif CONFIG_CAN1_DIVISOR == 2
+#    define CAN1_CCLK_DIVISOR SYSCON_PCLKSEL_CCLK2
+#  elif CONFIG_CAN1_DIVISOR == 4
+#    define CAN1_CCLK_DIVISOR SYSCON_PCLKSEL_CCLK4
+#  elif CONFIG_CAN1_DIVISOR == 6
+#    define CAN1_CCLK_DIVISOR SYSCON_PCLKSEL_CCLK6
+#  else
+#    error "Unsupported value of CONFIG_CAN1_DIVISOR"
+#  endif
+#endif
+
+#ifdef CONFIG_LPC17_CAN2
+
+   /* A CAN bit rate must be provided */
+
+#  ifndef CONFIG_CAN2_BAUD
+#    error "CONFIG_CAN2_BAUD is not defined"
+#  endif
+
+   /* If no divsor is provided, use a divisor of 4 */
+
+#  ifndef CONFIG_CAN2_DIVISOR
+#    define CONFIG_CAN2_DIVISOR 4
+#  endif
+
+   /* Get the SYSCON_PCLKSEL value for CAN2 the implements this divisor */
+
+#  if CONFIG_CAN2_DIVISOR == 1
+#    define CAN2_CCLK_DIVISOR SYSCON_PCLKSEL_CCLK
+#  elif CONFIG_CAN2_DIVISOR == 2
+#    define CAN2_CCLK_DIVISOR SYSCON_PCLKSEL_CCLK2
+#  elif CONFIG_CAN2_DIVISOR == 4
+#    define CAN2_CCLK_DIVISOR SYSCON_PCLKSEL_CCLK4
+#  elif CONFIG_CAN2_DIVISOR == 6
+#    define CAN2_CCLK_DIVISOR SYSCON_PCLKSEL_CCLK6
+#  else
+#    error "Unsupported value of CONFIG_CAN2_DIVISOR"
+#  endif
+#endif
+
 /* Debug ********************************************************************/
 /* Non-standard debug that may be enabled just for testing CAN */
 
@@ -1078,7 +1138,7 @@ FAR struct can_dev_s *lpc17_caninitialize(int port)
 
       regval  = can_getcommon(LPC17_SYSCON_PCLKSEL0);
       regval &= ~SYSCON_PCLKSEL0_CAN1_MASK;
-      regval |= (SYSCON_PCLKSEL_CCLK4 << SYSCON_PCLKSEL0_CAN1_SHIFT);
+      regval |= (CAN1_CCLK_DIVISOR << SYSCON_PCLKSEL0_CAN1_SHIFT);
       can_putcommon(LPC17_SYSCON_PCLKSEL0, regval);
 
       /* Configure CAN GPIO pins */
@@ -1105,7 +1165,7 @@ FAR struct can_dev_s *lpc17_caninitialize(int port)
 
       regval  = can_getcommon(LPC17_SYSCON_PCLKSEL0);
       regval &= ~SYSCON_PCLKSEL0_CAN2_MASK;
-      regval |= (SYSCON_PCLKSEL_CCLK4 << SYSCON_PCLKSEL0_CAN2_SHIFT);
+      regval |= (CAN2_CCLK_DIVISOR << SYSCON_PCLKSEL0_CAN2_SHIFT);
       can_putcommon(LPC17_SYSCON_PCLKSEL0, regval);
 
       /* Configure CAN GPIO pins */

nuttx/configs/lpcxpresso-lpc1768/README.txt

@@ -644,6 +644,18 @@ LPCXpresso Configuration Options
     CONFIG_UARTn_PARTIY - 0=no parity, 1=odd parity, 2=even parity
     CONFIG_UARTn_2STOP - Two stop bits
 
+  LPC17xx specific CAN device driver settings.  These settings all
+  require CONFIG_CAN:
+
+	CONFIG_CAN1_BAUD - CAN1 BAUD rate.  Required if CONFIG_LPC17_CAN1 is defined.
+	CONFIG_CAN2_BAUD - CAN1 BAUD rate.  Required if CONFIG_LPC17_CAN2 is defined.
+	CONFIG_CAN1_DIVISOR - CAN1 is clocked at CCLK divided by this number.
+	  (the CCLK frequency is divided by this number to get the CAN clock).
+	  Options = {1,2,4,6}. Default: 4.
+	CONFIG_CAN2_DIVISOR - CAN2 is clocked at CCLK divided by this number.
+	  (the CCLK frequency is divided by this number to get the CAN clock).
+	  Options = {1,2,4,6}. Default: 4.
+
   LPC17xx specific PHY/Ethernet device driver settings.  These setting
   also require CONFIG_NET and CONFIG_LPC17_ETHERNET.
 

nuttx/configs/mbed/README.txt

@@ -284,6 +284,18 @@ mbed Configuration Options
 	CONFIG_UARTn_PARTIY - 0=no parity, 1=odd parity, 2=even parity
 	CONFIG_UARTn_2STOP - Two stop bits
 
+  LPC17xx specific CAN device driver settings.  These settings all
+  require CONFIG_CAN:
+
+	CONFIG_CAN1_BAUD - CAN1 BAUD rate.  Required if CONFIG_LPC17_CAN1 is defined.
+	CONFIG_CAN2_BAUD - CAN1 BAUD rate.  Required if CONFIG_LPC17_CAN2 is defined.
+	CONFIG_CAN1_DIVISOR - CAN1 is clocked at CCLK divided by this number.
+	  (the CCLK frequency is divided by this number to get the CAN clock).
+	  Options = {1,2,4,6}. Default: 4.
+	CONFIG_CAN2_DIVISOR - CAN2 is clocked at CCLK divided by this number.
+	  (the CCLK frequency is divided by this number to get the CAN clock).
+	  Options = {1,2,4,6}. Default: 4.
+
   LPC17xx specific PHY/Ethernet device driver settings.  These setting
   also require CONFIG_NET and CONFIG_LPC17_ETHERNET.
 

nuttx/configs/nucleus2g/README.txt

@@ -396,6 +396,18 @@ Nucleus 2G Configuration Options
 	CONFIG_UARTn_PARTIY - 0=no parity, 1=odd parity, 2=even parity
 	CONFIG_UARTn_2STOP - Two stop bits
 
+  LPC17xx specific CAN device driver settings.  These settings all
+  require CONFIG_CAN:
+
+	CONFIG_CAN1_BAUD - CAN1 BAUD rate.  Required if CONFIG_LPC17_CAN1 is defined.
+	CONFIG_CAN2_BAUD - CAN1 BAUD rate.  Required if CONFIG_LPC17_CAN2 is defined.
+	CONFIG_CAN1_DIVISOR - CAN1 is clocked at CCLK divided by this number.
+	  (the CCLK frequency is divided by this number to get the CAN clock).
+	  Options = {1,2,4,6}. Default: 4.
+	CONFIG_CAN2_DIVISOR - CAN2 is clocked at CCLK divided by this number.
+	  (the CCLK frequency is divided by this number to get the CAN clock).
+	  Options = {1,2,4,6}. Default: 4.
+
   LPC17xx specific PHY/Ethernet device driver settings.  These setting
   also require CONFIG_NET and CONFIG_LPC17_ETHERNET.
 

nuttx/configs/olimex-lpc1766stk/README.txt

@@ -693,6 +693,18 @@ Olimex LPC1766-STK Configuration Options
 	CONFIG_UARTn_PARTIY - 0=no parity, 1=odd parity, 2=even parity
 	CONFIG_UARTn_2STOP - Two stop bits
 
+  LPC17xx specific CAN device driver settings.  These settings all
+  require CONFIG_CAN:
+
+	CONFIG_CAN1_BAUD - CAN1 BAUD rate.  Required if CONFIG_LPC17_CAN1 is defined.
+	CONFIG_CAN2_BAUD - CAN1 BAUD rate.  Required if CONFIG_LPC17_CAN2 is defined.
+	CONFIG_CAN1_DIVISOR - CAN1 is clocked at CCLK divided by this number.
+	  (the CCLK frequency is divided by this number to get the CAN clock).
+	  Default: 4
+	CONFIG_CAN2_DIVISOR - CAN2 is clocked at CCLK divided by this number.
+	  (the CCLK frequency is divided by this number to get the CAN clock).
+	  Default: 4
+
   LPC17xx specific PHY/Ethernet device driver settings.  These setting
   also require CONFIG_NET and CONFIG_LPC17_ETHERNET.