Unverified Commit 8ad07d79 authored by Quanyang Wang's avatar Quanyang Wang Committed by Mark Brown
Browse files

spi: spi-zynqmp-gqspi: transmit dummy circles by using the controller's internal functionality 



There is a data corruption issue that occurs in the reading operation
(cmd:0x6c) when transmitting common data as dummy circles.

The gqspi controller has the functionality to send dummy clock circles.
When writing data with the fields [receive, transmit, data_xfer] = [0,0,1]
to the Generic FIFO, and configuring the correct SPI mode, the controller
will transmit dummy circles.

So let's switch to hardware dummy cycles transfer to fix this issue.

Fixes: 1c26372e ("spi: spi-zynqmp-gqspi: Update driver to use spi-mem framework")
Signed-off-by: default avatarQuanyang Wang <quanyang.wang@windriver.com>
Reviewed-by: default avatarAmit Kumar Mahapatra <amit.kumar-mahapatra@xilinx.com>
Link: https://lore.kernel.org/r/20210408040223.23134-4-quanyang.wang@windriver.com


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent a0f65be6

drivers/spi/spi-zynqmp-gqspi.c

+18 −22
Original line number Diff line number Diff line
@@ -521,7 +521,7 @@ static void zynqmp_qspi_filltxfifo(struct zynqmp_qspi *xqspi, int size) 
{

	u32 count = 0, intermediate;



	while ((xqspi->bytes_to_transfer > 0) && (count < size)) {

	while ((xqspi->bytes_to_transfer > 0) && (count < size) && (xqspi->txbuf)) {

		memcpy(&intermediate, xqspi->txbuf, 4);

		zynqmp_gqspi_write(xqspi, GQSPI_TXD_OFST, intermediate);
@@ -580,7 +580,7 @@ static void zynqmp_qspi_fillgenfifo(struct zynqmp_qspi *xqspi, u8 nbits, 
		genfifoentry |= GQSPI_GENFIFO_DATA_XFER;

		genfifoentry |= GQSPI_GENFIFO_TX;

		transfer_len = xqspi->bytes_to_transfer;

	} else {

	} else if (xqspi->rxbuf) {

		genfifoentry &= ~GQSPI_GENFIFO_TX;

		genfifoentry |= GQSPI_GENFIFO_DATA_XFER;

		genfifoentry |= GQSPI_GENFIFO_RX;
@@ -588,6 +588,11 @@ static void zynqmp_qspi_fillgenfifo(struct zynqmp_qspi *xqspi, u8 nbits, 
			transfer_len = xqspi->dma_rx_bytes;

		else

			transfer_len = xqspi->bytes_to_receive;

	} else {

		/* Sending dummy circles here */

		genfifoentry &= ~(GQSPI_GENFIFO_TX | GQSPI_GENFIFO_RX);

		genfifoentry |= GQSPI_GENFIFO_DATA_XFER;

		transfer_len = xqspi->bytes_to_transfer;

	}

	genfifoentry |= zynqmp_qspi_selectspimode(xqspi, nbits);

	xqspi->genfifoentry = genfifoentry;
@@ -1011,32 +1016,23 @@ static int zynqmp_qspi_exec_op(struct spi_mem *mem, 
	}



	if (op->dummy.nbytes) {

		tmpbuf = kzalloc(op->dummy.nbytes, GFP_KERNEL | GFP_DMA);

		if (!tmpbuf)

			return -ENOMEM;

		memset(tmpbuf, 0xff, op->dummy.nbytes);

		reinit_completion(&xqspi->data_completion);

		xqspi->txbuf = tmpbuf;

		xqspi->txbuf = NULL;

		xqspi->rxbuf = NULL;

		xqspi->bytes_to_transfer = op->dummy.nbytes;

		/*

		 * xqspi->bytes_to_transfer here represents the dummy circles

		 * which need to be sent.

		 */

		xqspi->bytes_to_transfer = op->dummy.nbytes * 8 / op->dummy.buswidth;

		xqspi->bytes_to_receive = 0;

		zynqmp_qspi_write_op(xqspi, op->dummy.buswidth,

		/*

		 * Using op->data.buswidth instead of op->dummy.buswidth here because

		 * we need to use it to configure the correct SPI mode.

		 */

		zynqmp_qspi_write_op(xqspi, op->data.buswidth,

				     genfifoentry);

		zynqmp_gqspi_write(xqspi, GQSPI_CONFIG_OFST,

				   zynqmp_gqspi_read(xqspi, GQSPI_CONFIG_OFST) |

				   GQSPI_CFG_START_GEN_FIFO_MASK);

		zynqmp_gqspi_write(xqspi, GQSPI_IER_OFST,

				   GQSPI_IER_TXEMPTY_MASK |

				   GQSPI_IER_GENFIFOEMPTY_MASK |

				   GQSPI_IER_TXNOT_FULL_MASK);

		if (!wait_for_completion_interruptible_timeout

		    (&xqspi->data_completion, msecs_to_jiffies(1000))) {

			err = -ETIMEDOUT;

			kfree(tmpbuf);

			goto return_err;

		}



		kfree(tmpbuf);

	}



	if (op->data.nbytes) {