X-Git-Url: https://git.gag.com/?a=blobdiff_plain;f=src%2Fstm%2Fao_spi_stm.c;h=214092f6bb75922ca075bd404766416b650637e1;hb=61ad8e5bf428246ac89cad7cb9a1edf2ef735fd5;hp=3b5773b6ed75e70da31d498eaaf0ecf467356a18;hpb=69791ef235161fef404f682fd6955e7eed8dc125;p=fw%2Faltos diff --git a/src/stm/ao_spi_stm.c b/src/stm/ao_spi_stm.c index 3b5773b6..214092f6 100644 --- a/src/stm/ao_spi_stm.c +++ b/src/stm/ao_spi_stm.c @@ -84,12 +84,48 @@ validate_spi(struct stm_spi *stm_spi, int which, uint16_t len) #define validate_spi(stm_spi, which, len) do { (void) (which); (void) (len); } while (0) #endif +static void +ao_spi_run(uint8_t id, uint8_t which, uint16_t len) +{ + struct stm_spi *stm_spi = ao_spi_stm_info[id].stm_spi; + uint8_t mosi_dma_index = ao_spi_stm_info[id].mosi_dma_index; + uint8_t miso_dma_index = ao_spi_stm_info[id].miso_dma_index; + + validate_spi(stm_spi, which, len); + + stm_spi->cr2 = ((0 << STM_SPI_CR2_TXEIE) | + (0 << STM_SPI_CR2_RXNEIE) | + (0 << STM_SPI_CR2_ERRIE) | + (0 << STM_SPI_CR2_SSOE) | + (1 << STM_SPI_CR2_TXDMAEN) | + (1 << STM_SPI_CR2_RXDMAEN)); + + ao_dma_start(miso_dma_index); + ao_dma_start(mosi_dma_index); + + ao_arch_critical( + while (!ao_dma_done[miso_dma_index]) + ao_sleep(&ao_dma_done[miso_dma_index]); + ); + + while ((stm_spi->sr & (1 << STM_SPI_SR_TXE)) == 0); + while (stm_spi->sr & (1 << STM_SPI_SR_BSY)); + + validate_spi(stm_spi, which+1, len); + + stm_spi->cr2 = 0; + + ao_dma_done_transfer(mosi_dma_index); + ao_dma_done_transfer(miso_dma_index); +} + void ao_spi_send(const void *block, uint16_t len, uint8_t spi_index) { - struct stm_spi *stm_spi = ao_spi_stm_info[AO_SPI_INDEX(spi_index)].stm_spi; - uint8_t mosi_dma_index = ao_spi_stm_info[AO_SPI_INDEX(spi_index)].mosi_dma_index; - uint8_t miso_dma_index = ao_spi_stm_info[AO_SPI_INDEX(spi_index)].miso_dma_index; + uint8_t id = AO_SPI_INDEX(spi_index); + struct stm_spi *stm_spi = ao_spi_stm_info[id].stm_spi; + uint8_t mosi_dma_index = ao_spi_stm_info[id].mosi_dma_index; + uint8_t miso_dma_index = ao_spi_stm_info[id].miso_dma_index; /* Set up the transmit DMA to deliver data */ ao_dma_set_transfer(mosi_dma_index, @@ -105,9 +141,6 @@ ao_spi_send(const void *block, uint16_t len, uint8_t spi_index) (0 << STM_DMA_CCR_CIRC) | (STM_DMA_CCR_DIR_MEM_TO_PER << STM_DMA_CCR_DIR)); - /* Clear RXNE */ - (void) stm_spi->dr; - /* Set up the receive DMA -- when this is done, we know the SPI unit * is idle. Without this, we'd have to poll waiting for the BSY bit to * be cleared @@ -124,28 +157,17 @@ ao_spi_send(const void *block, uint16_t len, uint8_t spi_index) (0 << STM_DMA_CCR_PINC) | (0 << STM_DMA_CCR_CIRC) | (STM_DMA_CCR_DIR_PER_TO_MEM << STM_DMA_CCR_DIR)); - stm_spi->cr2 = ((0 << STM_SPI_CR2_TXEIE) | - (0 << STM_SPI_CR2_RXNEIE) | - (0 << STM_SPI_CR2_ERRIE) | - (0 << STM_SPI_CR2_SSOE) | - (1 << STM_SPI_CR2_TXDMAEN) | - (1 << STM_SPI_CR2_RXDMAEN)); - ao_dma_start(miso_dma_index); - ao_dma_start(mosi_dma_index); - ao_arch_critical( - while (!ao_dma_done[miso_dma_index]) - ao_sleep(&ao_dma_done[miso_dma_index]); - ); - ao_dma_done_transfer(mosi_dma_index); - ao_dma_done_transfer(miso_dma_index); + + ao_spi_run(id, 1, len); } void ao_spi_send_fixed(uint8_t value, uint16_t len, uint8_t spi_index) { - struct stm_spi *stm_spi = ao_spi_stm_info[AO_SPI_INDEX(spi_index)].stm_spi; - uint8_t mosi_dma_index = ao_spi_stm_info[AO_SPI_INDEX(spi_index)].mosi_dma_index; - uint8_t miso_dma_index = ao_spi_stm_info[AO_SPI_INDEX(spi_index)].miso_dma_index; + uint8_t id = AO_SPI_INDEX(spi_index); + struct stm_spi *stm_spi = ao_spi_stm_info[id].stm_spi; + uint8_t mosi_dma_index = ao_spi_stm_info[id].mosi_dma_index; + uint8_t miso_dma_index = ao_spi_stm_info[id].miso_dma_index; /* Set up the transmit DMA to deliver data */ ao_dma_set_transfer(mosi_dma_index, @@ -161,9 +183,6 @@ ao_spi_send_fixed(uint8_t value, uint16_t len, uint8_t spi_index) (0 << STM_DMA_CCR_CIRC) | (STM_DMA_CCR_DIR_MEM_TO_PER << STM_DMA_CCR_DIR)); - /* Clear RXNE */ - (void) stm_spi->dr; - /* Set up the receive DMA -- when this is done, we know the SPI unit * is idle. Without this, we'd have to poll waiting for the BSY bit to * be cleared @@ -180,27 +199,48 @@ ao_spi_send_fixed(uint8_t value, uint16_t len, uint8_t spi_index) (0 << STM_DMA_CCR_PINC) | (0 << STM_DMA_CCR_CIRC) | (STM_DMA_CCR_DIR_PER_TO_MEM << STM_DMA_CCR_DIR)); + + ao_spi_run(id, 3, len); +} + +void +ao_spi_start_bytes(uint8_t spi_index) +{ + uint8_t id = AO_SPI_INDEX(spi_index); + struct stm_spi *stm_spi = ao_spi_stm_info[id].stm_spi; + stm_spi->cr2 = ((0 << STM_SPI_CR2_TXEIE) | (0 << STM_SPI_CR2_RXNEIE) | (0 << STM_SPI_CR2_ERRIE) | (0 << STM_SPI_CR2_SSOE) | - (1 << STM_SPI_CR2_TXDMAEN) | - (1 << STM_SPI_CR2_RXDMAEN)); - ao_dma_start(miso_dma_index); - ao_dma_start(mosi_dma_index); - ao_arch_critical( - while (!ao_dma_done[miso_dma_index]) - ao_sleep(&ao_dma_done[miso_dma_index]); - ); - ao_dma_done_transfer(mosi_dma_index); - ao_dma_done_transfer(miso_dma_index); + (0 << STM_SPI_CR2_TXDMAEN) | + (0 << STM_SPI_CR2_RXDMAEN)); + validate_spi(stm_spi, 5, 0xffff); +} + +void +ao_spi_stop_bytes(uint8_t spi_index) +{ + uint8_t id = AO_SPI_INDEX(spi_index); + struct stm_spi *stm_spi = ao_spi_stm_info[id].stm_spi; + + while ((stm_spi->sr & (1 << STM_SPI_SR_TXE)) == 0) + ; + while (stm_spi->sr & (1 << STM_SPI_SR_BSY)) + ; + /* Clear the OVR flag */ + (void) stm_spi->dr; + (void) stm_spi->sr; + validate_spi(stm_spi, 6, 0xffff); + stm_spi->cr2 = 0; } void ao_spi_send_sync(const void *block, uint16_t len, uint8_t spi_index) { - uint8_t *b = block; - struct stm_spi *stm_spi = ao_spi_stm_info[AO_SPI_INDEX(spi_index)].stm_spi; + uint8_t id = AO_SPI_INDEX(spi_index); + const uint8_t *b = block; + struct stm_spi *stm_spi = ao_spi_stm_info[id].stm_spi; stm_spi->cr2 = ((0 << STM_SPI_CR2_TXEIE) | (0 << STM_SPI_CR2_RXNEIE) | @@ -208,22 +248,28 @@ ao_spi_send_sync(const void *block, uint16_t len, uint8_t spi_index) (0 << STM_SPI_CR2_SSOE) | (0 << STM_SPI_CR2_TXDMAEN) | (0 << STM_SPI_CR2_RXDMAEN)); - - /* Clear RXNE */ - (void) stm_spi->dr; - + validate_spi(stm_spi, 7, len); while (len--) { while (!(stm_spi->sr & (1 << STM_SPI_SR_TXE))); stm_spi->dr = *b++; } + while ((stm_spi->sr & (1 << STM_SPI_SR_TXE)) == 0) + ; + while (stm_spi->sr & (1 << STM_SPI_SR_BSY)) + ; + /* Clear the OVR flag */ + (void) stm_spi->dr; + (void) stm_spi->sr; + validate_spi(stm_spi, 8, len); } void ao_spi_recv(void *block, uint16_t len, uint8_t spi_index) { - struct stm_spi *stm_spi = ao_spi_stm_info[AO_SPI_INDEX(spi_index)].stm_spi; - uint8_t mosi_dma_index = ao_spi_stm_info[AO_SPI_INDEX(spi_index)].mosi_dma_index; - uint8_t miso_dma_index = ao_spi_stm_info[AO_SPI_INDEX(spi_index)].miso_dma_index; + uint8_t id = AO_SPI_INDEX(spi_index); + struct stm_spi *stm_spi = ao_spi_stm_info[id].stm_spi; + uint8_t mosi_dma_index = ao_spi_stm_info[id].mosi_dma_index; + uint8_t miso_dma_index = ao_spi_stm_info[id].miso_dma_index; spi_dev_null = 0xff; @@ -241,9 +287,6 @@ ao_spi_recv(void *block, uint16_t len, uint8_t spi_index) (0 << STM_DMA_CCR_CIRC) | (STM_DMA_CCR_DIR_MEM_TO_PER << STM_DMA_CCR_DIR)); - /* Clear RXNE */ - (void) stm_spi->dr; - /* Set up the receive DMA to capture data */ ao_dma_set_transfer(miso_dma_index, &stm_spi->dr, @@ -258,31 +301,16 @@ ao_spi_recv(void *block, uint16_t len, uint8_t spi_index) (0 << STM_DMA_CCR_CIRC) | (STM_DMA_CCR_DIR_PER_TO_MEM << STM_DMA_CCR_DIR)); - stm_spi->cr2 = ((0 << STM_SPI_CR2_TXEIE) | - (0 << STM_SPI_CR2_RXNEIE) | - (0 << STM_SPI_CR2_ERRIE) | - (0 << STM_SPI_CR2_SSOE) | - (1 << STM_SPI_CR2_TXDMAEN) | - (1 << STM_SPI_CR2_RXDMAEN)); - ao_dma_start(miso_dma_index); - ao_dma_start(mosi_dma_index); - - /* Wait until the SPI unit is done */ - ao_arch_critical( - while (!ao_dma_done[miso_dma_index]) - ao_sleep(&ao_dma_done[miso_dma_index]); - ); - - ao_dma_done_transfer(mosi_dma_index); - ao_dma_done_transfer(miso_dma_index); + ao_spi_run(id, 9, len); } void ao_spi_duplex(void *out, void *in, uint16_t len, uint8_t spi_index) { - struct stm_spi *stm_spi = ao_spi_stm_info[AO_SPI_INDEX(spi_index)].stm_spi; - uint8_t mosi_dma_index = ao_spi_stm_info[AO_SPI_INDEX(spi_index)].mosi_dma_index; - uint8_t miso_dma_index = ao_spi_stm_info[AO_SPI_INDEX(spi_index)].miso_dma_index; + uint8_t id = AO_SPI_INDEX(spi_index); + struct stm_spi *stm_spi = ao_spi_stm_info[id].stm_spi; + uint8_t mosi_dma_index = ao_spi_stm_info[id].mosi_dma_index; + uint8_t miso_dma_index = ao_spi_stm_info[id].miso_dma_index; /* Set up transmit DMA to send data */ ao_dma_set_transfer(mosi_dma_index, @@ -298,9 +326,6 @@ ao_spi_duplex(void *out, void *in, uint16_t len, uint8_t spi_index) (0 << STM_DMA_CCR_CIRC) | (STM_DMA_CCR_DIR_MEM_TO_PER << STM_DMA_CCR_DIR)); - /* Clear RXNE */ - (void) stm_spi->dr; - /* Set up the receive DMA to capture data */ ao_dma_set_transfer(miso_dma_index, &stm_spi->dr, @@ -314,24 +339,7 @@ ao_spi_duplex(void *out, void *in, uint16_t len, uint8_t spi_index) (0 << STM_DMA_CCR_PINC) | (0 << STM_DMA_CCR_CIRC) | (STM_DMA_CCR_DIR_PER_TO_MEM << STM_DMA_CCR_DIR)); - - stm_spi->cr2 = ((0 << STM_SPI_CR2_TXEIE) | - (0 << STM_SPI_CR2_RXNEIE) | - (0 << STM_SPI_CR2_ERRIE) | - (0 << STM_SPI_CR2_SSOE) | - (1 << STM_SPI_CR2_TXDMAEN) | - (1 << STM_SPI_CR2_RXDMAEN)); - ao_dma_start(miso_dma_index); - ao_dma_start(mosi_dma_index); - - /* Wait until the SPI unit is done */ - ao_arch_critical( - while (!ao_dma_done[miso_dma_index]) - ao_sleep(&ao_dma_done[miso_dma_index]); - ); - - ao_dma_done_transfer(mosi_dma_index); - ao_dma_done_transfer(miso_dma_index); + ao_spi_run(id, 11, len); } static void @@ -339,44 +347,36 @@ ao_spi_disable_index(uint8_t spi_index) { /* Disable current config */ - switch (AO_SPI_INDEX(spi_index)) { - case STM_SPI_INDEX(1): - switch (spi_index) { - case AO_SPI_1_PA5_PA6_PA7: - stm_gpio_set(&stm_gpioa, 5, 1); - stm_moder_set(&stm_gpioa, 5, STM_MODER_OUTPUT); - stm_moder_set(&stm_gpioa, 6, STM_MODER_INPUT); - stm_moder_set(&stm_gpioa, 7, STM_MODER_OUTPUT); - break; - case AO_SPI_1_PB3_PB4_PB5: - stm_gpio_set(&stm_gpiob, 3, 1); - stm_moder_set(&stm_gpiob, 3, STM_MODER_OUTPUT); - stm_moder_set(&stm_gpiob, 4, STM_MODER_INPUT); - stm_moder_set(&stm_gpiob, 5, STM_MODER_OUTPUT); - break; - case AO_SPI_1_PE13_PE14_PE15: - stm_gpio_set(&stm_gpioe, 13, 1); - stm_moder_set(&stm_gpioe, 13, STM_MODER_OUTPUT); - stm_moder_set(&stm_gpioe, 14, STM_MODER_INPUT); - stm_moder_set(&stm_gpioe, 15, STM_MODER_OUTPUT); - break; - } + switch (spi_index) { + case AO_SPI_1_PA5_PA6_PA7: + stm_gpio_set(&stm_gpioa, 5, 1); + stm_moder_set(&stm_gpioa, 5, STM_MODER_OUTPUT); + stm_moder_set(&stm_gpioa, 6, STM_MODER_INPUT); + stm_moder_set(&stm_gpioa, 7, STM_MODER_OUTPUT); break; - case STM_SPI_INDEX(2): - switch (spi_index) { - case AO_SPI_2_PB13_PB14_PB15: - stm_gpio_set(&stm_gpiob, 13, 1); - stm_moder_set(&stm_gpiob, 13, STM_MODER_OUTPUT); - stm_moder_set(&stm_gpiob, 14, STM_MODER_INPUT); - stm_moder_set(&stm_gpiob, 15, STM_MODER_OUTPUT); - break; - case AO_SPI_2_PD1_PD3_PD4: - stm_gpio_set(&stm_gpiod, 1, 1); - stm_moder_set(&stm_gpiod, 1, STM_MODER_OUTPUT); - stm_moder_set(&stm_gpiod, 3, STM_MODER_INPUT); - stm_moder_set(&stm_gpiod, 4, STM_MODER_OUTPUT); - break; - } + case AO_SPI_1_PB3_PB4_PB5: + stm_gpio_set(&stm_gpiob, 3, 1); + stm_moder_set(&stm_gpiob, 3, STM_MODER_OUTPUT); + stm_moder_set(&stm_gpiob, 4, STM_MODER_INPUT); + stm_moder_set(&stm_gpiob, 5, STM_MODER_OUTPUT); + break; + case AO_SPI_1_PE13_PE14_PE15: + stm_gpio_set(&stm_gpioe, 13, 1); + stm_moder_set(&stm_gpioe, 13, STM_MODER_OUTPUT); + stm_moder_set(&stm_gpioe, 14, STM_MODER_INPUT); + stm_moder_set(&stm_gpioe, 15, STM_MODER_OUTPUT); + break; + case AO_SPI_2_PB13_PB14_PB15: + stm_gpio_set(&stm_gpiob, 13, 1); + stm_moder_set(&stm_gpiob, 13, STM_MODER_OUTPUT); + stm_moder_set(&stm_gpiob, 14, STM_MODER_INPUT); + stm_moder_set(&stm_gpiob, 15, STM_MODER_OUTPUT); + break; + case AO_SPI_2_PD1_PD3_PD4: + stm_gpio_set(&stm_gpiod, 1, 1); + stm_moder_set(&stm_gpiod, 1, STM_MODER_OUTPUT); + stm_moder_set(&stm_gpiod, 3, STM_MODER_INPUT); + stm_moder_set(&stm_gpiod, 4, STM_MODER_OUTPUT); break; } } @@ -384,39 +384,33 @@ ao_spi_disable_index(uint8_t spi_index) static void ao_spi_enable_index(uint8_t spi_index) { - switch (AO_SPI_INDEX(spi_index)) { - case STM_SPI_INDEX(1): - switch (spi_index) { - case AO_SPI_1_PA5_PA6_PA7: - stm_afr_set(&stm_gpioa, 5, STM_AFR_AF5); - stm_afr_set(&stm_gpioa, 6, STM_AFR_AF5); - stm_afr_set(&stm_gpioa, 7, STM_AFR_AF5); - break; - case AO_SPI_1_PB3_PB4_PB5: - stm_afr_set(&stm_gpiob, 3, STM_AFR_AF5); - stm_afr_set(&stm_gpiob, 4, STM_AFR_AF5); - stm_afr_set(&stm_gpiob, 5, STM_AFR_AF5); - break; - case AO_SPI_1_PE13_PE14_PE15: - stm_afr_set(&stm_gpioe, 13, STM_AFR_AF5); - stm_afr_set(&stm_gpioe, 14, STM_AFR_AF5); - stm_afr_set(&stm_gpioe, 15, STM_AFR_AF5); - break; - } + /* Enable new config + */ + switch (spi_index) { + case AO_SPI_1_PA5_PA6_PA7: + stm_afr_set(&stm_gpioa, 5, STM_AFR_AF5); + stm_afr_set(&stm_gpioa, 6, STM_AFR_AF5); + stm_afr_set(&stm_gpioa, 7, STM_AFR_AF5); break; - case STM_SPI_INDEX(2): - switch (spi_index) { - case AO_SPI_2_PB13_PB14_PB15: - stm_afr_set(&stm_gpiob, 13, STM_AFR_AF5); - stm_afr_set(&stm_gpiob, 14, STM_AFR_AF5); - stm_afr_set(&stm_gpiob, 15, STM_AFR_AF5); - break; - case AO_SPI_2_PD1_PD3_PD4: - stm_afr_set(&stm_gpiod, 1, STM_AFR_AF5); - stm_afr_set(&stm_gpiod, 3, STM_AFR_AF5); - stm_afr_set(&stm_gpiod, 4, STM_AFR_AF5); - break; - } + case AO_SPI_1_PB3_PB4_PB5: + stm_afr_set(&stm_gpiob, 3, STM_AFR_AF5); + stm_afr_set(&stm_gpiob, 4, STM_AFR_AF5); + stm_afr_set(&stm_gpiob, 5, STM_AFR_AF5); + break; + case AO_SPI_1_PE13_PE14_PE15: + stm_afr_set(&stm_gpioe, 13, STM_AFR_AF5); + stm_afr_set(&stm_gpioe, 14, STM_AFR_AF5); + stm_afr_set(&stm_gpioe, 15, STM_AFR_AF5); + break; + case AO_SPI_2_PB13_PB14_PB15: + stm_afr_set(&stm_gpiob, 13, STM_AFR_AF5); + stm_afr_set(&stm_gpiob, 14, STM_AFR_AF5); + stm_afr_set(&stm_gpiob, 15, STM_AFR_AF5); + break; + case AO_SPI_2_PD1_PD3_PD4: + stm_afr_set(&stm_gpiod, 1, STM_AFR_AF5); + stm_afr_set(&stm_gpiod, 3, STM_AFR_AF5); + stm_afr_set(&stm_gpiod, 4, STM_AFR_AF5); break; } } @@ -426,20 +420,7 @@ ao_spi_config(uint8_t spi_index, uint32_t speed) { uint8_t id = AO_SPI_INDEX(spi_index); struct stm_spi *stm_spi = ao_spi_stm_info[id].stm_spi; - stm_spi->cr1 = ((0 << STM_SPI_CR1_BIDIMODE) | /* Three wire mode */ - (0 << STM_SPI_CR1_BIDIOE) | - (0 << STM_SPI_CR1_CRCEN) | /* CRC disabled */ - (0 << STM_SPI_CR1_CRCNEXT) | - (0 << STM_SPI_CR1_DFF) | - (0 << STM_SPI_CR1_RXONLY) | - (1 << STM_SPI_CR1_SSM) | /* Software SS handling */ - (1 << STM_SPI_CR1_SSI) | /* ... */ - (0 << STM_SPI_CR1_LSBFIRST) | /* Big endian */ - (1 << STM_SPI_CR1_SPE) | /* Enable SPI unit */ - (speed << STM_SPI_CR1_BR) | /* baud rate to pclk/4 */ - (1 << STM_SPI_CR1_MSTR) | - (0 << STM_SPI_CR1_CPOL) | /* Format 0 */ - (0 << STM_SPI_CR1_CPHA)); + if (spi_index != ao_spi_index[id]) { /* Disable old config @@ -454,6 +435,21 @@ ao_spi_config(uint8_t spi_index, uint32_t speed) */ ao_spi_index[id] = spi_index; } + stm_spi->cr1 = ((0 << STM_SPI_CR1_BIDIMODE) | /* Three wire mode */ + (0 << STM_SPI_CR1_BIDIOE) | + (0 << STM_SPI_CR1_CRCEN) | /* CRC disabled */ + (0 << STM_SPI_CR1_CRCNEXT) | + (0 << STM_SPI_CR1_DFF) | + (0 << STM_SPI_CR1_RXONLY) | + (1 << STM_SPI_CR1_SSM) | /* Software SS handling */ + (1 << STM_SPI_CR1_SSI) | /* ... */ + (0 << STM_SPI_CR1_LSBFIRST) | /* Big endian */ + (1 << STM_SPI_CR1_SPE) | /* Enable SPI unit */ + (speed << STM_SPI_CR1_BR) | /* baud rate to pclk/4 */ + (1 << STM_SPI_CR1_MSTR) | + (0 << STM_SPI_CR1_CPOL) | /* Format 0 */ + (0 << STM_SPI_CR1_CPHA)); + validate_spi(stm_spi, 13, 0); } uint8_t @@ -471,6 +467,7 @@ void ao_spi_get(uint8_t spi_index, uint32_t speed) { uint8_t id = AO_SPI_INDEX(spi_index); + ao_mutex_get(&ao_spi_mutex[id]); ao_spi_config(spi_index, speed); } @@ -494,13 +491,16 @@ ao_spi_channel_init(uint8_t spi_index) ao_spi_disable_index(spi_index); stm_spi->cr1 = 0; - (void) stm_spi->sr; 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 any pending data and error flags */ + (void) stm_spi->dr; + (void) stm_spi->sr; } #if DEBUG