px4fmu-v2:Use simple HW versioning API to differentiate V2 variant at runtime.

There are several boards that share the px4fmu-v2 build as px4fmu-v3 build.

   It was initially envisioned, that the build would be binary compatable and
   the RC script would probe different sensors and determine at runtime the
   HW type. Unfortunately, a failed sensor, can result in mis-detection
   of the HW and result in an improper start up and not detect the HW
   failure.

   All these boards's bootloader report board type as px4fmu-v2.
   This precludes and automated selection of the correct fw if it
   had been built, by a different build i.e. px4fmu-cube etc.

   We need a way to deal with the slight differences in HW that effect
   the operations of drivers and board level functions that are different
   from the FMUv2 pinout and bus utilization.

   1) FMUv3 AKA Cube 2.0 and Cube 2.1 Bothe I2C busses are external.
      This effected the mag on GPS2 not reporting Internal and
      having the wrong rotation applied.

   2) FMUv3 does not performa a SPI buss reset correctly.
      FMUv2 provides a SPI1 buss reset. But FMUv3 is on
      SPI4. To complicate matters the CS cross bus
      boundries.

   3) PixhawkMini reused a signal that was associated with SPI4
      as a SPI1 ready signal.

   Based on hardware differnce in the use of PB4 and PB12 this code
   detects: FMUv2,  the Cube, and PixhawkMini and provides the
   simple common API for retriving the type, version and revision.

   On FmuV5 this same API will be used.

src/drivers/boards/px4fmu-v2/px4fmu2_init.c

@@ -116,6 +116,14 @@ extern void led_on(int led);
 extern void led_off(int led);
 __END_DECLS
 
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+#if defined(BOARD_HAS_SIMPLE_HW_VERSIONING)
+static int hw_version = -1;
+static int hw_revision = -1;
+static char hw_type[4] = HW_VER_TYPE_INIT;
+#endif
 /****************************************************************************
  * Protected Functions
  ****************************************************************************/
@@ -144,6 +152,123 @@ __EXPORT void board_peripheral_reset(int ms)
 	stm32_gpiowrite(GPIO_VDD_5V_PERIPH_EN, 0);
 }
 
+/************************************************************************************
+  * Name: determin_hw_version
+ *
+ * Description:
+ *
+ * This function looks at HW deltas to determine what the
+ * build is running on using the following criteria:
+ *
+ * MSN  PB12   FMUv2                Cube             MINI
+ * CAN2_RX       CONECTOR             MX30521          NC
+ * PU.PD         1,0                   1,1             1,0
+ *
+ * LSN  PB4    FMUv2                Cube             MINI
+ *               ACCEL_DRDY LSM303D    NC              NC
+ * PU.PD         0,0                   1,0             1,0
+
+ *  PB12:PB4
+ *  ud   ud
+ *  10   00 - 0x8 FMUv2
+ *  11   10 - 0xE Cube AKA V2.0
+ *  10   10 - 0xA PixhawkMini
+ *
+ *  This will return OK on success and -1 on not supported
+ *
+ *  hw_type Initial state is {'V','2',0, 0}
+ *   V 2    - FMUv2
+ *   V 3 0  - FMUv3 2.0
+ *   V 3 1  - FMUv3 2.1 - not differentiateable,
+ *   V 2 M  - FMUv2 Mini
+ *
+ ************************************************************************************/
+
+#if defined(BOARD_HAS_SIMPLE_HW_VERSIONING)
+static int determin_hw_version(int *version, int *revision)
+{
+	*revision = -1; /* unknown */
+	int rv = 0;
+	int pos = 0;
+	stm32_configgpio(GPIO_PULLDOWN | (HW_VER_PB4 & ~GPIO_PUPD_MASK));
+	up_udelay(10);
+	rv |= stm32_gpioread(HW_VER_PB4) << pos++;
+	stm32_configgpio(HW_VER_PB4);
+	up_udelay(10);
+	rv |= stm32_gpioread(HW_VER_PB4) << pos++;
+
+	int votes = 16;
+	int ones[2] = {0, 0};
+	int zeros[2] = {0, 0};
+
+	while (votes--) {
+		stm32_configgpio(GPIO_PULLDOWN | (HW_VER_PB12 & ~GPIO_PUPD_MASK));
+		up_udelay(10);
+		stm32_gpioread(HW_VER_PB12) ? ones[0]++ : zeros[0]++;
+		stm32_configgpio(HW_VER_PB12);
+		up_udelay(10);
+		stm32_gpioread(HW_VER_PB12) ? ones[1]++ : zeros[1]++;
+	}
+
+	if (ones[0] > zeros[0]) {
+		rv |= 1 << pos;
+	}
+
+	pos++;
+
+	if (ones[1] > zeros[1]) {
+		rv |= 1 << pos;
+	}
+
+	stm32_configgpio(HW_VER_PB4_INIT);
+	stm32_configgpio(HW_VER_PB12_INIT);
+	*version = rv;
+	return OK;
+}
+
+/************************************************************************************
+ * Name: board_get_hw_type_name
+ *
+ * Description:
+ *   Optional returns a string defining the HW type
+ *
+ *
+ ************************************************************************************/
+
+__EXPORT const char *board_get_hw_type_name()
+{
+	return (const char *) hw_type;
+}
+
+/************************************************************************************
+ * Name: board_get_hw_version
+ *
+ * Description:
+ *   Optional returns a integer HW version
+ *
+ *
+ ************************************************************************************/
+
+__EXPORT int board_get_hw_version()
+{
+	return  HW_VER_SIMPLE(hw_version);
+}
+
+/************************************************************************************
+ * Name: board_get_hw_revision
+ *
+ * Description:
+ *   Optional returns a integer HW revision
+ *
+ *
+ ************************************************************************************/
+
+__EXPORT int board_get_hw_revision()
+{
+	return  hw_revision;
+}
+#endif // BOARD_HAS_SIMPLE_HW_VERSIONING
+
 /************************************************************************************
  * Name: stm32_boardinitialize
  *
@@ -236,6 +361,29 @@ __EXPORT int board_app_initialize(uintptr_t arg)
 #  error platform is dependent on c++ both CONFIG_HAVE_CXX and CONFIG_HAVE_CXXINITIALIZE must be defined.
 #endif
 
+#if defined(BOARD_HAS_SIMPLE_HW_VERSIONING)
+
+	if (OK == determin_hw_version(&hw_version, & hw_revision)) {
+		switch (hw_version) {
+		default:
+		case 0x8:
+			break;
+
+		case 0xE:
+			hw_type[1]++;
+			hw_type[2] = '0';
+			break;
+
+		case 0xA:
+			hw_type[2] = 'M';
+			break;
+		}
+
+		PX4_INFO("Ver 0x%1X : Rev %x %s", hw_version, hw_revision, hw_type);
+	}
+
+#endif // BOARD_HAS_SIMPLE_HW_VERSIONING
+
 	/* configure the high-resolution time/callout interface */
 	hrt_init();
 

src/drivers/boards/px4fmu-v3/board_config.h

@@ -43,5 +43,16 @@
  * Included Files
  ****************************************************************************************************/
 
+/* Run time Hardware detection */
+#define BOARD_HAS_SIMPLE_HW_VERSIONING 1
+#define HW_VER_PB4             (GPIO_INPUT|GPIO_PULLUP|GPIO_PORTB|GPIO_PIN4)
+#define HW_VER_PB12            (GPIO_INPUT|GPIO_PULLUP|GPIO_PORTB|GPIO_PIN12)
+#define HW_VER_PB4_INIT        (GPIO_EXTI_ACCEL_DRDY)
+#define HW_VER_PB12_INIT       (GPIO_INPUT|GPIO_FLOAT|GPIO_PORTB|GPIO_PIN12)
+#define HW_VER_FMUV2_STATE     0x8 /* PB12:PU:1 PB12:PD:0 PB4:PU:0 PB4PD:0 */
+#define HW_VER_FMUV3_STATE     0xE /* PB12:PU:1 PB12:PD:1 PB4:PU:1 PB4PD:0 */
+#define HW_VER_FMUV2MINI_STATE 0xA /* PB12:PU:1 PB12:PD:0 PB4:PU:1 PB4PD:0 */
+#define HW_VER_TYPE_INIT {'V','2',0, 0}
+
 #include "../px4fmu-v2/board_config.h"
 #define PX4_SPIDEV_ICM_20608  PX4_SPIDEV_ACCEL_MAG // PixhawkMini has ICM_20608 on GPIO_SPI_CS_ACCEL_MAG