From 1a63c47cf9fa3e6eb47c3ca278899802cf45a014 Mon Sep 17 00:00:00 2001
From: Ian Martin <ian@locicontrols.com>
Date: Tue, 15 Apr 2014 17:36:55 -0400
Subject: [PATCH] CC2538: Add CONF parameters to select boot loader backdoor
 pin and logic level.

---
 cpu/cc2538/dev/flash-cca.h       |  1 +
 platform/cc2538dk/contiki-conf.h |  9 +++++++++
 platform/cc2538dk/startup-gcc.c  | 16 +++++++++++++---
 3 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/cpu/cc2538/dev/flash-cca.h b/cpu/cc2538/dev/flash-cca.h
index 2dff2978b..a81bab702 100644
--- a/cpu/cc2538/dev/flash-cca.h
+++ b/cpu/cc2538/dev/flash-cca.h
@@ -58,6 +58,7 @@
 #define FLASH_CCA_BOOTLDR_CFG_ACTIVE_HIGH       0x08000000 /**< Selected pin on pad A active high */
 #define FLASH_CCA_BOOTLDR_CFG_PORT_A_PIN_M      0x07000000 /**< Selected pin on pad A mask */
 #define FLASH_CCA_BOOTLDR_CFG_PORT_A_PIN_S      24         /**< Selected pin on pad A shift */
+#define FLASH_CCA_BOOTLDR_CFG_PORT_A_LEVEL_S    27         /**< Pin level shift */
 /** @} */
 /*---------------------------------------------------------------------------*/
 /** \name Image valid definitions
diff --git a/platform/cc2538dk/contiki-conf.h b/platform/cc2538dk/contiki-conf.h
index 964d01074..2188fa353 100644
--- a/platform/cc2538dk/contiki-conf.h
+++ b/platform/cc2538dk/contiki-conf.h
@@ -48,7 +48,16 @@ typedef uint32_t rtimer_clock_t;
 #ifndef FLASH_CCA_CONF_BOOTLDR_BACKDOOR
 #define FLASH_CCA_CONF_BOOTLDR_BACKDOOR	1 /**<Enable the boot loader backdoor */
 #endif
+
+#ifndef FLASH_CCA_CONF_BOOTLDR_BACKDOOR_PIN
+#define FLASH_CCA_CONF_BOOTLDR_BACKDOOR_PIN   3 /**< Pin PA_3 (Select button) activates the boot loader */
+#endif
+
+#ifndef FLASH_CCA_CONF_BOOTLDR_BACKDOOR_LEVEL
+#define FLASH_CCA_CONF_BOOTLDR_BACKDOOR_LEVEL 0 /**< A logic low level activates the boot loader */
+#endif
 /** @} */
+
 /*---------------------------------------------------------------------------*/
 /**
  * \name USB 'core' configuration
diff --git a/platform/cc2538dk/startup-gcc.c b/platform/cc2538dk/startup-gcc.c
index 860a481d2..0aaec8f5d 100644
--- a/platform/cc2538dk/startup-gcc.c
+++ b/platform/cc2538dk/startup-gcc.c
@@ -65,9 +65,19 @@ void udma_err_isr(void);
 
 /* Boot Loader Backdoor selection */
 #if FLASH_CCA_CONF_BOOTLDR_BACKDOOR
-/* Backdoor enabled, on PA_3 (Select button) */
-#define FLASH_CCA_BOOTLDR_CFG (FLASH_CCA_BOOTLDR_CFG_ENABLE \
-  | ((3 << FLASH_CCA_BOOTLDR_CFG_PORT_A_PIN_S) & FLASH_CCA_BOOTLDR_CFG_PORT_A_PIN_M))
+  /* Backdoor enabled */
+
+  #if ( (FLASH_CCA_CONF_BOOTLDR_BACKDOOR_LEVEL < 0) || (FLASH_CCA_CONF_BOOTLDR_BACKDOOR_LEVEL > 1) )
+    #error Invalid boot loader backdoor pin level. Please set FLASH_CCA_CONF_BOOTLDR_BACKDOOR_LEVEL to 0 (logic low) or 1 (logic high).
+  #endif
+
+  #if ( (FLASH_CCA_CONF_BOOTLDR_BACKDOOR_PIN < 0) || (FLASH_CCA_CONF_BOOTLDR_BACKDOOR_PIN > 7) )
+    #error Invalid boot loader backdoor pin. Please set FLASH_CCA_CONF_BOOTLDR_BACKDOOR_PIN between 0 and 7 (indicating PA0 - PA7).
+  #endif
+
+  #define FLASH_CCA_BOOTLDR_CFG ( FLASH_CCA_BOOTLDR_CFG_ENABLE \
+    | (FLASH_CCA_CONF_BOOTLDR_BACKDOOR_LEVEL << FLASH_CCA_BOOTLDR_CFG_PORT_A_LEVEL_S) \
+    | (FLASH_CCA_CONF_BOOTLDR_BACKDOOR_PIN << FLASH_CCA_BOOTLDR_CFG_PORT_A_PIN_S) )
 #else
 #define FLASH_CCA_BOOTLDR_CFG FLASH_CCA_BOOTLDR_CFG_DISABLE
 #endif