From 1147db45a44bef98bc4e558474d4d615e775edfb Mon Sep 17 00:00:00 2001
From: Damjan Adamic <projectkk2glider@gmail.com>
Date: Fri, 4 Mar 2016 21:23:19 +0100
Subject: [PATCH] Re #3340: Cleanup Re #3340: Software reboot tested and
 working on Horus

---
 radio/src/targets/horus/board_horus.h         |  6 ++--
 radio/src/targets/horus/pwr_driver.cpp        | 28 +++++++++++++++++++
 .../targets/horus/startup_stm32f40_41xxx.s    |  2 ++
 3 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/radio/src/targets/horus/board_horus.h b/radio/src/targets/horus/board_horus.h
index cc9fc16a9..e6d066f77 100644
--- a/radio/src/targets/horus/board_horus.h
+++ b/radio/src/targets/horus/board_horus.h
@@ -204,8 +204,9 @@ void checkRotaryEncoder(void);
 void watchdogInit(unsigned int duration);
 #define wdt_enable(x) //   watchdogInit(1500)
 #define wdt_reset()   //  IWDG->KR = 0xAAAA
-#define WAS_RESET_BY_WATCHDOG()   (RCC->CSR & (RCC_CSR_WDGRSTF | RCC_CSR_WWDGRSTF))
-#define WAS_RESET_BY_SOFTWARE()   (RCC->CSR & RCC_CSR_SFTRSTF)
+#define WAS_RESET_BY_WATCHDOG()               (RCC->CSR & (RCC_CSR_WDGRSTF | RCC_CSR_WWDGRSTF))
+#define WAS_RESET_BY_SOFTWARE()               (RCC->CSR & RCC_CSR_SFTRSTF)
+#define WAS_RESET_BY_WATCHDOG_OR_SOFTWARE()   (RCC->CSR & (RCC_CSR_WDGRSTF | RCC_CSR_WWDGRSTF | RCC_CSR_SFTRSTF))
 #endif
 
 // ADC driver
@@ -247,6 +248,7 @@ void pwrInit(void);
 uint32_t pwrCheck(void);
 void pwrOn(void);
 void pwrOff(void);
+void pwrResetHandler(void);
 uint32_t pwrPressed(void);
 uint32_t pwrPressedDuration(void);
 #define UNEXPECTED_SHUTDOWN()   (false) // (g_eeGeneral.unexpectedShutdown)
diff --git a/radio/src/targets/horus/pwr_driver.cpp b/radio/src/targets/horus/pwr_driver.cpp
index ab83fec2f..ab9583845 100644
--- a/radio/src/targets/horus/pwr_driver.cpp
+++ b/radio/src/targets/horus/pwr_driver.cpp
@@ -85,3 +85,31 @@ uint32_t pwrPressed()
 {
   return GPIO_ReadInputDataBit(PWR_GPIO, PWR_SWITCH_GPIO_PIN) == Bit_RESET;
 }
+
+void pwrResetHandler()
+{
+  RCC->AHB1ENR |= RCC_AHB1ENR_GPIOJEN;
+
+  // these two NOPs are needed (see STM32F errata sheet) before the peripheral 
+  // register can be written after the peripheral clock was enabled
+  __ASM volatile ("nop");
+  __ASM volatile ("nop");
+
+  // Turn soft power ON now, but only if we got started because of the watchdog
+  // or software reset. If the radio was started by user pressing the power button
+  // then that button is providing power and we don't need to enable it here.
+  //
+  // If we were to turn it on here indiscriminately, then the radio can go into the 
+  // power on/off loop after being powered off by the user. (issue #2790)
+  if (WAS_RESET_BY_WATCHDOG_OR_SOFTWARE()) {
+    GPIO_InitTypeDef GPIO_InitStructure;
+    GPIO_InitStructure.GPIO_Pin = PWR_ON_GPIO_PIN;
+    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
+    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
+    GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
+    GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
+    GPIO_Init(PWR_GPIO, &GPIO_InitStructure);
+
+    pwrOn();
+  }
+}
\ No newline at end of file
diff --git a/radio/src/targets/horus/startup_stm32f40_41xxx.s b/radio/src/targets/horus/startup_stm32f40_41xxx.s
index 4fb8604f7..8a6579aca 100644
--- a/radio/src/targets/horus/startup_stm32f40_41xxx.s
+++ b/radio/src/targets/horus/startup_stm32f40_41xxx.s
@@ -71,6 +71,8 @@ defined in linker script */
   .type  Reset_Handler, %function
 Reset_Handler:  
 
+  bl pwrResetHandler    /*jump to WDT reset handler where soft power control pin is turned on as soon as possible */
+
 /* Copy the data segment initializers from flash to SRAM */  
   movs  r1, #0
   b  LoopCopyDataInit