AP_HAL_Linux: don't manually define number of spi devices

It's error-prone, let's make the compiler define it for us.

libraries/AP_HAL_Linux/SPIDriver.cpp

@@ -1,3 +1,4 @@
+#include <AP_Common.h>
 #include <AP_HAL.h>
 
 #if CONFIG_HAL_BOARD == HAL_BOARD_LINUX
@@ -23,7 +24,7 @@ extern const AP_HAL::HAL& hal;
 #define KHZ (1000U)
 
 #if CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_PXF || CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_ERLE
-LinuxSPIDeviceDriver LinuxSPIDeviceManager::_device[LINUX_SPI_DEVICE_NUM_DEVICES] = {
+LinuxSPIDeviceDriver LinuxSPIDeviceManager::_device[] = {
     // different SPI tables per board subtype
     LinuxSPIDeviceDriver(1, 0, AP_HAL::SPIDevice_LSM9DS0_AM, SPI_MODE_3, 8, BBB_P9_17,  10*MHZ,10*MHZ),
     LinuxSPIDeviceDriver(1, 0, AP_HAL::SPIDevice_LSM9DS0_G,  SPI_MODE_3, 8, BBB_P8_9,   10*MHZ,10*MHZ),
@@ -34,13 +35,13 @@ LinuxSPIDeviceDriver LinuxSPIDeviceManager::_device[LINUX_SPI_DEVICE_NUM_DEVICES
     LinuxSPIDeviceDriver(2, 0, AP_HAL::SPIDevice_Dataflash,  SPI_MODE_3, 8, BBB_P8_12,  6*MHZ, 6*MHZ),
 };
 #elif CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_NAVIO
-LinuxSPIDeviceDriver LinuxSPIDeviceManager::_device[LINUX_SPI_DEVICE_NUM_DEVICES] = {
+LinuxSPIDeviceDriver LinuxSPIDeviceManager::_device[] = {
     /* MPU9250 is restricted to 1MHz for non-data and interrupt registers */
     LinuxSPIDeviceDriver(0, 1, AP_HAL::SPIDevice_MPU9250, SPI_MODE_0, 8, SPI_CS_KERNEL,  1*MHZ, 16*MHZ),
     LinuxSPIDeviceDriver(0, 0, AP_HAL::SPIDevice_Ublox, SPI_MODE_0, 8, SPI_CS_KERNEL,  250*KHZ, 4*MHZ),
 };
 #elif CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_BBBMINI
-LinuxSPIDeviceDriver LinuxSPIDeviceManager::_device[LINUX_SPI_DEVICE_NUM_DEVICES] = {
+LinuxSPIDeviceDriver LinuxSPIDeviceManager::_device[] = {
     /* MPU9250 is restricted to 1MHz for non-data and interrupt registers */
     LinuxSPIDeviceDriver(2, 0, AP_HAL::SPIDevice_MPU9250,    SPI_MODE_3, 8, SPI_CS_KERNEL,  1*MHZ, 20*MHZ),
     LinuxSPIDeviceDriver(2, 1, AP_HAL::SPIDevice_MS5611,     SPI_MODE_3, 8, SPI_CS_KERNEL,  10*MHZ,10*MHZ),
@@ -50,6 +51,8 @@ LinuxSPIDeviceDriver LinuxSPIDeviceManager::_device[LINUX_SPI_DEVICE_NUM_DEVICES
 LinuxSPIDeviceDriver LinuxSPIDeviceManager::_device[0];
 #endif
 
+#define LINUX_SPI_DEVICE_NUM_DEVICES ARRAY_SIZE(LinuxSPIDeviceManager::_device)
+
 // have a separate semaphore per bus
 LinuxSemaphore LinuxSPIDeviceManager::_semaphore[LINUX_SPI_MAX_BUSES];
 

libraries/AP_HAL_Linux/SPIDriver.h

@@ -5,16 +5,6 @@
 #include <AP_HAL_Linux.h>
 #include "Semaphores.h"
 
-#if CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_PXF || CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_ERLE
-#define LINUX_SPI_DEVICE_NUM_DEVICES 6
-#elif CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_NAVIO
-#define LINUX_SPI_DEVICE_NUM_DEVICES 2
-#elif CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_BBBMINI
-#define LINUX_SPI_DEVICE_NUM_DEVICES 2
-#else
-#define LINUX_SPI_DEVICE_NUM_DEVICES 0
-#endif
-
 // Most platforms won't need to declare the spidev bus offset
 #ifndef LINUX_SPIDEV_BUS_OFFSET
 #define LINUX_SPIDEV_BUS_OFFSET 0
@@ -65,7 +55,7 @@ public:
     static void transaction(LinuxSPIDeviceDriver &driver, const uint8_t *tx, uint8_t *rx, uint16_t len);
 
 private:
-    static LinuxSPIDeviceDriver _device[LINUX_SPI_DEVICE_NUM_DEVICES];
+    static LinuxSPIDeviceDriver _device[];
     static LinuxSemaphore _semaphore[LINUX_SPI_MAX_BUSES];
 };