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Commit d9f58812 authored by Ricardo Ribalda Delgado's avatar Ricardo Ribalda Delgado Committed by Mark Brown
Browse files

spi/xilinx: Do not inhibit transmission in polling mode 



When no irq is used, there is no need to inhibit the transmission for
every transaction. This inhibition was implemented to avoid a race
condition with the irq handler.

Signed-off-by: default avatarRicardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 5fe11cc0

drivers/spi/spi-xilinx.c

+15 −10
Original line number Original line Diff line number Diff line
@@ -163,6 +163,7 @@ static void xspi_rx32(struct xilinx_spi *xspi) 
static void xspi_init_hw(struct xilinx_spi *xspi)

static void xspi_init_hw(struct xilinx_spi *xspi)

{

{

	void __iomem *regs_base = xspi->regs;

	void __iomem *regs_base = xspi->regs;

	u32 inhibit;





	/* Reset the SPI device */

	/* Reset the SPI device */

	xspi->write_fn(XIPIF_V123B_RESET_MASK,

	xspi->write_fn(XIPIF_V123B_RESET_MASK,
@@ -173,16 +174,19 @@ static void xspi_init_hw(struct xilinx_spi *xspi) 
	xspi->write_fn(XSPI_INTR_TX_EMPTY,

	xspi->write_fn(XSPI_INTR_TX_EMPTY,

			regs_base + XIPIF_V123B_IIER_OFFSET);

			regs_base + XIPIF_V123B_IIER_OFFSET);

	/* Enable the global IPIF interrupt */

	/* Enable the global IPIF interrupt */

	if (xspi->irq >= 0)

	if (xspi->irq >= 0) {

		xspi->write_fn(XIPIF_V123B_GINTR_ENABLE,

		xspi->write_fn(XIPIF_V123B_GINTR_ENABLE,

			regs_base + XIPIF_V123B_DGIER_OFFSET);

			regs_base + XIPIF_V123B_DGIER_OFFSET);

	else

		inhibit = XSPI_CR_TRANS_INHIBIT;

	} else {

		xspi->write_fn(0, regs_base + XIPIF_V123B_DGIER_OFFSET);

		xspi->write_fn(0, regs_base + XIPIF_V123B_DGIER_OFFSET);

		inhibit = 0;

	}

	/* Deselect the slave on the SPI bus */

	/* Deselect the slave on the SPI bus */

	xspi->write_fn(0xffff, regs_base + XSPI_SSR_OFFSET);

	xspi->write_fn(0xffff, regs_base + XSPI_SSR_OFFSET);

	/* Disable the transmitter, enable Manual Slave Select Assertion,

	/* Disable the transmitter, enable Manual Slave Select Assertion,

	 * put SPI controller into master mode, and enable it */

	 * put SPI controller into master mode, and enable it */

	xspi->write_fn(XSPI_CR_TRANS_INHIBIT | XSPI_CR_MANUAL_SSELECT |

	xspi->write_fn(inhibit | XSPI_CR_MANUAL_SSELECT |

		XSPI_CR_MASTER_MODE | XSPI_CR_ENABLE | XSPI_CR_TXFIFO_RESET |

		XSPI_CR_MASTER_MODE | XSPI_CR_ENABLE | XSPI_CR_TXFIFO_RESET |

		XSPI_CR_RXFIFO_RESET, regs_base + XSPI_CR_OFFSET);

		XSPI_CR_RXFIFO_RESET, regs_base + XSPI_CR_OFFSET);

}

}
@@ -252,7 +256,7 @@ static int xilinx_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t) 
	reinit_completion(&xspi->done);

	reinit_completion(&xspi->done);





	while (xspi->remaining_bytes) {

	while (xspi->remaining_bytes) {

		u16 cr;

		u16 cr = 0;

		int n_words;

		int n_words;





		n_words = (xspi->remaining_bytes * 8) / xspi->bits_per_word;

		n_words = (xspi->remaining_bytes * 8) / xspi->bits_per_word;
@@ -263,13 +267,13 @@ static int xilinx_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t) 
		/* Start the transfer by not inhibiting the transmitter any

		/* Start the transfer by not inhibiting the transmitter any

		 * longer

		 * longer

		 */

		 */



		if (xspi->irq >= 0) {

			cr = xspi->read_fn(xspi->regs + XSPI_CR_OFFSET) &

			cr = xspi->read_fn(xspi->regs + XSPI_CR_OFFSET) &

							~XSPI_CR_TRANS_INHIBIT;

							~XSPI_CR_TRANS_INHIBIT;

			xspi->write_fn(cr, xspi->regs + XSPI_CR_OFFSET);

			xspi->write_fn(cr, xspi->regs + XSPI_CR_OFFSET);



		if (xspi->irq >= 0)

			wait_for_completion(&xspi->done);

			wait_for_completion(&xspi->done);

		else

		} else

			while (!(xspi->read_fn(xspi->regs + XSPI_SR_OFFSET) &

			while (!(xspi->read_fn(xspi->regs + XSPI_SR_OFFSET) &

						XSPI_SR_TX_EMPTY_MASK))

						XSPI_SR_TX_EMPTY_MASK))

				;

				;
@@ -279,6 +283,7 @@ static int xilinx_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t) 
		 * transmitter while the Isr refills the transmit register/FIFO,

		 * transmitter while the Isr refills the transmit register/FIFO,

		 * or make sure it is stopped if we're done.

		 * or make sure it is stopped if we're done.

		 */

		 */

		if (xspi->irq >= 0)

			xspi->write_fn(cr | XSPI_CR_TRANS_INHIBIT,

			xspi->write_fn(cr | XSPI_CR_TRANS_INHIBIT,

			       xspi->regs + XSPI_CR_OFFSET);

			       xspi->regs + XSPI_CR_OFFSET);