altos: Add one-byte SPI output routine for LPC and STM cores

[fw/altos] / src / stm / ao_arch_funcs.h

diff --git a/src/stm/ao_arch_funcs.h b/src/stm/ao_arch_funcs.h
index 6b38032cc352a296b75731095d2fe10b76297f44..087e00d91da77d13075a80fa98c9234884a04a02 100644 (file)
--- a/src/stm/ao_arch_funcs.h
+++ b/src/stm/ao_arch_funcs.h
@@ -82,6 +82,34 @@ ao_spi_send_fixed(uint8_t value, uint16_t len, uint8_t spi_index);
 void
 ao_spi_send_sync(void *block, uint16_t len, uint8_t spi_index);
 
+static inline void
+ao_spi_send_byte(uint8_t byte, uint8_t spi_index)
+{
+       struct stm_spi  *stm_spi;
+
+       switch (AO_SPI_INDEX(spi_index)) {
+       case 0:
+               stm_spi = &stm_spi1;
+               break;
+       case 1:
+               stm_spi = &stm_spi2;
+               break;
+       }
+
+       stm_spi->cr2 = ((0 << STM_SPI_CR2_TXEIE) |
+                       (0 << STM_SPI_CR2_RXNEIE) |
+                       (0 << STM_SPI_CR2_ERRIE) |
+                       (0 << STM_SPI_CR2_SSOE) |
+                       (0 << STM_SPI_CR2_TXDMAEN) |
+                       (0 << STM_SPI_CR2_RXDMAEN));
+
+       /* Clear RXNE */
+       (void) stm_spi->dr;
+
+       while (!(stm_spi->sr & (1 << STM_SPI_SR_TXE)));
+       stm_spi->dr = byte;
+}
+
 void
 ao_spi_recv(void *block, uint16_t len, uint8_t spi_index);