NRF52x SPI capabilities: rx/tx buffers can have different sizes

Author: mprse

targets/TARGET_NORDIC/TARGET_NRF5x/TARGET_NRF52/spi_api.c

@@ -138,6 +138,7 @@ void spi_get_capabilities(PinName ssel, bool slave, spi_capabilities_t *cap)
         cap->hw_cs_handle = false;                  // irrelevant in slave mode
         cap->slave_delay_between_symbols_ns = 2500; // 2.5 us
         cap->clk_modes = 0x0f;                      // all clock modes
+        cap->tx_rx_buffers_equal_length = false;    // rx/tx buffers can have different sizes
 #if DEVICE_SPI_ASYNCH
         cap->async_mode = true;
 #else
@@ -151,6 +152,7 @@ void spi_get_capabilities(PinName ssel, bool slave, spi_capabilities_t *cap)
         cap->hw_cs_handle = false;                // to be determined later based on ssel
         cap->slave_delay_between_symbols_ns = 0;  // irrelevant in master mode
         cap->clk_modes = 0x0f;                    // all clock modes
+        cap->tx_rx_buffers_equal_length = false;  // rx/tx buffers can have different sizes
 #if DEVICE_SPI_ASYNCH
         cap->async_mode = true;
 #else