From 45d89fdba8bd681e82de883f2d1e173b9ec61297 Mon Sep 17 00:00:00 2001
From: andreika-git <andreika-git@users.noreply.github.com>
Date: Fri, 22 Dec 2017 15:49:03 +0200
Subject: [PATCH]  Backup NV-RAM refactor (#518)

* Backup NV-RAM refactor

* More comments on BACKUP_IGNITION_SWITCH_COUNTER
---
 firmware/hw_layer/backup_ram.cpp | 33 +++++++++++++++++++++++++++++
 firmware/hw_layer/backup_ram.h   | 36 ++++++++++++++++++++++++++++++++
 firmware/hw_layer/hw_layer.mk    |  3 ++-
 firmware/hw_layer/stepper.cpp    |  4 ++--
 firmware/hw_layer/stepper.h      |  1 +
 5 files changed, 74 insertions(+), 3 deletions(-)
 create mode 100644 firmware/hw_layer/backup_ram.cpp
 create mode 100644 firmware/hw_layer/backup_ram.h

diff --git a/firmware/hw_layer/backup_ram.cpp b/firmware/hw_layer/backup_ram.cpp
new file mode 100644
index 0000000000..ea98e5c91d
--- /dev/null
+++ b/firmware/hw_layer/backup_ram.cpp
@@ -0,0 +1,33 @@
+/**
+ * @file	backup_ram.cpp
+ *
+ * @date Dec 19, 2017
+ */
+
+#include "backup_ram.h"
+
+uint32_t backupRamLoad(backup_ram_e idx) {
+	switch (idx) {
+	case BACKUP_STEPPER_POS:
+		return RTCD1.rtc->BKP0R & 0xffff;
+	case BACKUP_IGNITION_SWITCH_COUNTER:
+		return (RTCD1.rtc->BKP0R >> 16) & 0xff;
+	default:
+		//scheduleMsg(logger, "Invalid backup ram idx %d", idx);
+		return 0;
+	}
+}
+
+void backupRamSave(backup_ram_e idx, uint32_t value) {
+	switch (idx) {
+	case BACKUP_STEPPER_POS:
+		RTCD1.rtc->BKP0R = (RTCD1.rtc->BKP0R & ~0x0000ffff) | (value & 0xffff);
+		break;
+	case BACKUP_IGNITION_SWITCH_COUNTER:
+		RTCD1.rtc->BKP0R = (RTCD1.rtc->BKP0R & ~0x00ff0000) | ((value & 0xff) << 16);
+		break;
+	default:
+		//scheduleMsg(logger, "Invalid backup ram idx %d, value 0x08x", idx, value);
+		break;
+	}
+}
diff --git a/firmware/hw_layer/backup_ram.h b/firmware/hw_layer/backup_ram.h
new file mode 100644
index 0000000000..1ce331d1e8
--- /dev/null
+++ b/firmware/hw_layer/backup_ram.h
@@ -0,0 +1,36 @@
+/**
+ * @file	backup_ram.cpp
+ * @brief	Non-volatile backup-RAM registers support
+ *
+ * @date Dec 19, 2017
+ */
+
+#ifndef BACKUP_RAM_H_
+#define BACKUP_RAM_H_
+
+#include "main.h"
+#include "efiGpio.h"
+
+typedef enum {
+	/**
+	 * IAC Stepper motor position, 16-bit (stored in BKP0R 0..15)
+	 * Used in stepper.cpp
+	 */
+	BACKUP_STEPPER_POS,
+	/**
+	 * Ignition switch counter, 8-bit (stored in BKP0R 16..23)
+	 * The counter stores the number of times the ignition switch is turned on. Used for prime injection pulse.
+	 * We need a protection against 'fake' ignition switch on and off (i.e. no engine started), to avoid repeated prime pulses.
+	 * So we check and update the ignition switch counter in non-volatile backup-RAM.
+	 * See startPrimeInjectionPulse() in controllers/trigger/main_trigger_callback.cpp
+	 */
+	BACKUP_IGNITION_SWITCH_COUNTER,
+} backup_ram_e;
+
+
+// load data from backup-power RTC registers (non-volatile memory)
+uint32_t backupRamLoad(backup_ram_e idx);
+// use backup-power RTC registers (non-volatile memory) to store the data
+void backupRamSave(backup_ram_e idx, uint32_t value);
+
+#endif /* BACKUP_RAM_H_ */
diff --git a/firmware/hw_layer/hw_layer.mk b/firmware/hw_layer/hw_layer.mk
index d219273147..cd088f1ae8 100644
--- a/firmware/hw_layer/hw_layer.mk
+++ b/firmware/hw_layer/hw_layer.mk
@@ -30,5 +30,6 @@ HW_LAYER_EMS_CPP = $(HW_LAYER_EGT_CPP) \
 	$(PROJECT_DIR)/hw_layer/servo.cpp \
 	$(PROJECT_DIR)/hw_layer/io_pins.cpp \
 	$(PROJECT_DIR)/hw_layer/stm32f4/mpu_util.cpp \
-	$(PROJECT_DIR)/hw_layer/rtc_helper.cpp
+	$(PROJECT_DIR)/hw_layer/rtc_helper.cpp \
+	$(PROJECT_DIR)/hw_layer/backup_ram.cpp
 	
\ No newline at end of file
diff --git a/firmware/hw_layer/stepper.cpp b/firmware/hw_layer/stepper.cpp
index 2b35b25fe2..5f90aa8721 100644
--- a/firmware/hw_layer/stepper.cpp
+++ b/firmware/hw_layer/stepper.cpp
@@ -20,11 +20,11 @@ static Logging *logger;
 
 static void saveStepperPos(int pos) {
 	// use backup-power RTC registers to store the data
-	RTCD1.rtc->BKP0R = (pos + 1);
+	backupRamSave(BACKUP_STEPPER_POS, pos + 1);
 }
 
 static int loadStepperPos() {
-	return (int)RTCD1.rtc->BKP0R - 1;
+	return (int)backupRamLoad(BACKUP_STEPPER_POS) - 1;
 }
 
 static msg_t stThread(StepperMotor *motor) {
diff --git a/firmware/hw_layer/stepper.h b/firmware/hw_layer/stepper.h
index 084935e552..28357c23a4 100644
--- a/firmware/hw_layer/stepper.h
+++ b/firmware/hw_layer/stepper.h
@@ -9,6 +9,7 @@
 
 #include "main.h"
 #include "efiGpio.h"
+#include "backup_ram.h"
 
 class StepperMotor {
 public: