drivers/spi/spi-bcm2835.c

91  * @tfr: SPI transfer currently processed
126 	struct spi_transfer *tfr;
412 					struct spi_transfer *tfr,
442  * @tfr: SPI transfer
486 					  struct spi_transfer *tfr,
492 	bs->tfr		 = tfr;
497 	if (bs->tx_buf && !sg_is_last(&tfr->tx_sg.sgl[0]))
498 		bs->tx_prologue = sg_dma_len(&tfr->tx_sg.sgl[0]) & 3;
500 	if (bs->rx_buf && !sg_is_last(&tfr->rx_sg.sgl[0])) {
501 		bs->rx_prologue = sg_dma_len(&tfr->rx_sg.sgl[0]) & 3;
504 			if (!bs->tx_buf || sg_is_last(&tfr->tx_sg.sgl[0])) {
509 					!(sg_dma_len(&tfr->tx_sg.sgl[0]) & ~3);
531 					   sg_dma_address(&tfr->rx_sg.sgl[0]),
534 		sg_dma_address(&tfr->rx_sg.sgl[0]) += bs->rx_prologue;
535 		sg_dma_len(&tfr->rx_sg.sgl[0])     -= bs->rx_prologue;
557 		sg_dma_address(&tfr->tx_sg.sgl[0]) += bs->tx_prologue;
558 		sg_dma_len(&tfr->tx_sg.sgl[0])     -= bs->tx_prologue;
560 		sg_dma_len(&tfr->tx_sg.sgl[0])      = 0;
561 		sg_dma_address(&tfr->tx_sg.sgl[1]) += 4;
562 		sg_dma_len(&tfr->tx_sg.sgl[1])     -= 4;
576 	struct spi_transfer *tfr = bs->tfr;
582 		sg_dma_address(&tfr->rx_sg.sgl[0]) -= bs->rx_prologue;
583 		sg_dma_len(&tfr->rx_sg.sgl[0])     += bs->rx_prologue;
590 		sg_dma_address(&tfr->tx_sg.sgl[0]) -= bs->tx_prologue;
591 		sg_dma_len(&tfr->tx_sg.sgl[0])     += bs->tx_prologue;
593 		sg_dma_len(&tfr->tx_sg.sgl[0])      = bs->tx_prologue - 4;
594 		sg_dma_address(&tfr->tx_sg.sgl[1]) -= 4;
595 		sg_dma_len(&tfr->tx_sg.sgl[1])     += 4;
663  * @tfr: SPI transfer
668  * Prepare and submit a DMA descriptor for the TX or RX sglist of @tfr.
672 				  struct spi_transfer *tfr,
689 		nents = tfr->tx_sg.nents;
690 		sgl   = tfr->tx_sg.sgl;
691 		flags = tfr->rx_buf ? 0 : DMA_PREP_INTERRUPT;
695 		nents = tfr->rx_sg.nents;
696 		sgl   = tfr->rx_sg.sgl;
711 	} else if (!tfr->rx_buf) {
726  * @tfr: SPI transfer
771 					struct spi_transfer *tfr,
786 	bcm2835_spi_transfer_prologue(ctlr, tfr, bs, cs);
790 		ret = bcm2835_spi_prepare_sg(ctlr, tfr, bs, target, true);
816 		ret = bcm2835_spi_prepare_sg(ctlr, tfr, bs, target, false);
854 				struct spi_transfer *tfr)
857 	if (tfr->len < BCM2835_SPI_DMA_MIN_LENGTH)
999 					 struct spi_transfer *tfr,
1042 							    tfr, cs, false);
1054 				    struct spi_transfer *tfr)
1063 	spi_hz = tfr->speed_hz;
1077 	tfr->effective_speed_hz = cdiv ? (bs->clk_hz / cdiv) : (bs->clk_hz / 65536);
1081 	if (spi->mode & SPI_3WIRE && tfr->rx_buf)
1085 	bs->tx_buf = tfr->tx_buf;
1086 	bs->rx_buf = tfr->rx_buf;
1087 	bs->tx_len = tfr->len;
1088 	bs->rx_len = tfr->len;
1097 	byte_limit = hz_per_byte ? tfr->effective_speed_hz / hz_per_byte : 1;
1100 	if (tfr->len < byte_limit)
1101 		return bcm2835_spi_transfer_one_poll(ctlr, spi, tfr, cs);
1107 	if (ctlr->can_dma && bcm2835_spi_can_dma(ctlr, spi, tfr))
1108 		return bcm2835_spi_transfer_one_dma(ctlr, tfr, target, cs);
1111 	return bcm2835_spi_transfer_one_irq(ctlr, spi, tfr, cs, true);