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atmel-samd: Correctly wait for the SPI DMA transaction to finish.

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This commit is contained in:
Scott Shawcroft 2017-05-12 13:11:30 -07:00
parent c138d0f025
commit 6984425f5d
1 changed files with 10 additions and 5 deletions
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15
atmel-samd/shared_dma.c
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@ -106,15 +106,18 @@ enum status_code shared_dma_write(Sercom* sercom, const uint8_t* buffer, uint32_
return status;
}
// Wait for the transfer to finish.
// Wait for the dma transfer to finish.
while (general_dma_tx.job_status == STATUS_BUSY) {}
// Wait for the SPI transfer to complete.
while (sercom->SPI.INTFLAG.bit.TXC == 0) {}
// This transmit will cause the RX buffer overflow but we're OK with that.
// So, read the garbage data and clear the overflow flag.
sercom->SPI.DATA.reg;
sercom->SPI.DATA.reg;
// So, read the garbage and clear the overflow flag.
while (sercom->SPI.INTFLAG.bit.RXC == 1) {
sercom->SPI.DATA.reg;
}
sercom->SPI.STATUS.bit.BUFOVF = 1;
sercom->SPI.DATA.reg;
return general_dma_tx.job_status;
}
@ -160,5 +163,7 @@ enum status_code shared_dma_read(Sercom* sercom, uint8_t* buffer, uint32_t lengt
// Wait for the transfer to finish.
while (general_dma_rx.job_status == STATUS_BUSY) {}
while (sercom->SPI.INTFLAG.bit.RXC == 1) {}
return general_dma_rx.job_status;
}