From 9bf469ac327f164c858506f077d41d63d5c4d5b7 Mon Sep 17 00:00:00 2001
From: blckmn <blackman@xtra.com.au>
Date: Sun, 1 Jan 2017 12:32:32 +1100
Subject: [PATCH] UART1 SP inversion fix (BlueJayF4)

---
 src/main/target/BLUEJAYF4/hardware_revision.c | 20 +++++------
 src/main/target/BLUEJAYF4/hardware_revision.h |  7 ++--
 src/main/target/BLUEJAYF4/initialisation.c    | 33 ++++++++++++++-----
 3 files changed, 37 insertions(+), 23 deletions(-)

diff --git a/src/main/target/BLUEJAYF4/hardware_revision.c b/src/main/target/BLUEJAYF4/hardware_revision.c
index cb70d05f7..95db1c618 100644
--- a/src/main/target/BLUEJAYF4/hardware_revision.c
+++ b/src/main/target/BLUEJAYF4/hardware_revision.c
@@ -46,6 +46,14 @@ void detectHardwareRevision(void)
     */
     if (!IORead(pin1)) {
         hardwareRevision = BJF4_REV3;
+
+        IO_t pin2 = IOGetByTag(IO_TAG(PB13));
+        IOInit(pin2, OWNER_SYSTEM, 2);
+        IOConfigGPIO(pin2, IOCFG_IPU);
+        
+        if (!IORead(pin2)) {
+            hardwareRevision = BJF4_REV4;
+        }        
     } else {
         IO_t pin2 = IOGetByTag(IO_TAG(PB13));
         IOInit(pin2, OWNER_SYSTEM, 2);
@@ -62,18 +70,6 @@ void detectHardwareRevision(void)
         hardwareRevision = BJF4_REV2;
         return;
     }
-
-    /*
-        enable the UART1 inversion PC9
-
-        TODO: once param groups are in place, inverter outputs
-        can be moved to be simple IO outputs, and merely set them
-        HI or LO in configuration.
-    */
-    IO_t uart1invert = IOGetByTag(IO_TAG(PC9));
-    IOInit(uart1invert, OWNER_INVERTER, 2);
-    IOConfigGPIO(uart1invert, IOCFG_AF_PP);
-    IOLo(uart1invert);
 }
 
 void updateHardwareRevision(void)
diff --git a/src/main/target/BLUEJAYF4/hardware_revision.h b/src/main/target/BLUEJAYF4/hardware_revision.h
index 0a2886a16..d2cad3af9 100644
--- a/src/main/target/BLUEJAYF4/hardware_revision.h
+++ b/src/main/target/BLUEJAYF4/hardware_revision.h
@@ -18,10 +18,11 @@
 
 typedef enum bjf4HardwareRevision_t {
     UNKNOWN = 0,
-    BJF4_REV1,  // Flash
-    BJF4_REV2,  // SDCard
-    BJF4_REV3,  // SDCard + Flash
+    BJF4_REV1,       // Flash
+    BJF4_REV2,       // SDCard
+    BJF4_REV3,       // SDCard + Flash
     BJF4_MINI_REV3A, // Flash (20x20 mini format)
+    BJF4_REV4        // SDCard only - improved UART1 inversion
 } bjf4HardwareRevision_e;
 
 extern uint8_t hardwareRevision;
diff --git a/src/main/target/BLUEJAYF4/initialisation.c b/src/main/target/BLUEJAYF4/initialisation.c
index a11301baa..389f12e64 100644
--- a/src/main/target/BLUEJAYF4/initialisation.c
+++ b/src/main/target/BLUEJAYF4/initialisation.c
@@ -28,16 +28,33 @@
 
 void targetPreInit(void)
 {
-    /* enable the built in inverter if telemetry is setup for the UART1 */
-    if (serialConfig()->portConfigs[SERIAL_PORT_USART1].functionMask & FUNCTION_TELEMETRY_SMARTPORT && 
-        telemetryConfig()->telemetry_inversion &&
-        feature(FEATURE_TELEMETRY)) {
-        IO_t io = IOGetByTag(IO_TAG(UART1_INVERTER));
-        IOInit(io, OWNER_INVERTER, 1);
-        IOConfigGPIO(io, IOCFG_OUT_PP);
-        IOHi(io);
+    switch (hardwareRevision) {
+    case BJF4_REV3:
+    case BJF4_MINI_REV3A:
+    case BJF4_REV4:
+        break;
+    default:
+        return;
     }
     
+    IO_t inverter = IOGetByTag(IO_TAG(UART1_INVERTER));
+    IOInit(inverter, OWNER_INVERTER, 1);
+    IOConfigGPIO(inverter, IOCFG_OUT_PP);
+    
+    bool high = false;
+    serialPortConfig_t *portConfig = serialFindPortConfiguration(SERIAL_PORT_USART1);
+    if (portConfig) {
+        bool smartportEnabled = (portConfig->functionMask & FUNCTION_TELEMETRY_SMARTPORT);
+        if (smartportEnabled && (telemetryConfig()->telemetry_inversion) && (feature(FEATURE_TELEMETRY))) {
+            high = true;
+        }
+    }
+    /* reverse this for rev4, as it does not use the XOR gate */
+    if (hardwareRevision == BJF4_REV4) {
+        high = !high;
+    }
+    IOWrite(inverter, high);
+    
     /* ensure the CS pin for the flash is pulled hi so any SD card initialisation does not impact the chip */
     if (hardwareRevision == BJF4_REV3) {
         IO_t io = IOGetByTag(IO_TAG(M25P16_CS_PIN));