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Commit 4f12b5e5 authored by Geert Uytterhoeven's avatar Geert Uytterhoeven Committed by Mark Brown
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spi: rspi: Add DMA support for QSPI on R-Car Gen2 



Enable DMA support for QSPI on R-Car Gen2, for Single, Dual, and Quad SPI
Transfers.

Performance figures for reading from a QSPI FLASH driven at 24.375 MHz
on r8a7791/koelsch:
  - Single:  1.1 Mbps PIO, 23 Mbps DMA
  - Dual  : 12.7 Mbps PIO, 48 Mbps DMA
  - Quad  : 13   Mbps PIO, 70 Mbps DMA

Signed-off-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: default avatarMark Brown <broonie@linaro.org>
parent 03e627c5

drivers/spi/spi-rspi.c

+9 −0
Original line number Diff line number Diff line
@@ -642,6 +642,9 @@ static int qspi_transfer_out_in(struct rspi_data *rspi, 


	qspi_receive_init(rspi);



	if (rspi->master->can_dma && __rspi_can_dma(rspi, xfer))

		return rspi_dma_transfer(rspi, &xfer->tx_sg, &xfer->rx_sg);



	ret = rspi_pio_transfer(rspi, xfer->tx_buf, xfer->rx_buf, xfer->len);

	if (ret < 0)

		return ret;
@@ -656,6 +659,9 @@ static int qspi_transfer_out(struct rspi_data *rspi, struct spi_transfer *xfer) 
{

	int ret;



	if (rspi->master->can_dma && __rspi_can_dma(rspi, xfer))

		return rspi_dma_transfer(rspi, &xfer->tx_sg, NULL);



	ret = rspi_pio_transfer(rspi, xfer->tx_buf, NULL, xfer->len);

	if (ret < 0)

		return ret;
@@ -668,6 +674,9 @@ static int qspi_transfer_out(struct rspi_data *rspi, struct spi_transfer *xfer) 


static int qspi_transfer_in(struct rspi_data *rspi, struct spi_transfer *xfer)

{

	if (rspi->master->can_dma && __rspi_can_dma(rspi, xfer))

		return rspi_dma_transfer(rspi, NULL, &xfer->rx_sg);



	return rspi_pio_transfer(rspi, NULL, xfer->rx_buf, xfer->len);

}