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Commit b42e0359 authored by Geert Uytterhoeven's avatar Geert Uytterhoeven Committed by Mark Brown
Browse files

spi: rspi: Use core SPI_MASTER_MUST_[RT]X handling 



RSPI needs dummy transfers to generate the SPI clock on receive.
RSPI-RZ and QSPI always do both transmit and receive.

Use the SPI core SPI_MASTER_MUST_RX/SPI_MASTER_MUST_TX infrastructure
instead of checking for the presence of buffers and providing dummy data
ourselves (for PIO), or providing a dummy buffer (for DMA).

rspi_receive_dma() now provides full duplex DMA transfers on RSPI, and is
renamed to rspi_send_receive_dma().

As the SPI core will always provide a TX buffer, the logic to choose
between DMA send and DMA send/receive in rspi_transfer_one() now has to
check for the presence of an RX buffer. Likewise for the DMA availability
tests in rspi_is_dma().

The buffer tests in qspi_transfer_one() are now always true, so they're
removed.

Signed-off-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: default avatarMark Brown <broonie@linaro.org>
parent 9c5de2c1

drivers/spi/spi-rspi.c

+58 −74
Original line number Diff line number Diff line
@@ -183,8 +183,6 @@ 
#define SPBFCR_TXTRG_MASK	0x30	/* Transmit Buffer Data Triggering Number */

#define SPBFCR_RXTRG_MASK	0x07	/* Receive Buffer Data Triggering Number */



#define DUMMY_DATA		0x00



struct rspi_data {

	void __iomem *addr;

	u32 max_speed_hz;
@@ -252,6 +250,7 @@ struct spi_ops { 
	int (*transfer_one)(struct spi_master *master, struct spi_device *spi,

			    struct spi_transfer *xfer);

	u16 mode_bits;

	u16 flags;

};



/*
@@ -552,42 +551,38 @@ static void qspi_receive_init(const struct rspi_data *rspi) 
	rspi_write8(rspi, 0, QSPI_SPBFCR);

}



static int rspi_receive_dma(struct rspi_data *rspi, struct spi_transfer *t)

static int rspi_send_receive_dma(struct rspi_data *rspi, struct spi_transfer *t)

{

	struct scatterlist sg, sg_dummy;

	void *dummy = NULL, *rx_buf = t->rx_buf;

	struct dma_async_tx_descriptor *desc, *desc_dummy;

	struct scatterlist sg_rx, sg_tx;

	const void *tx_buf = t->tx_buf;

	void *rx_buf = t->rx_buf;

	struct dma_async_tx_descriptor *desc_tx, *desc_rx;

	unsigned int len = t->len;

	int ret = 0;



	/* prepare dummy transfer to generate SPI clocks */

	dummy = kzalloc(len, GFP_KERNEL);

	if (!dummy) {

		ret = -ENOMEM;

		goto end_nomap;

	}

	if (!rspi_dma_map_sg(&sg_dummy, dummy, len, rspi->chan_tx,

			     DMA_TO_DEVICE)) {

		ret = -EFAULT;

		goto end_nomap;

	}

	desc_dummy = dmaengine_prep_slave_sg(rspi->chan_tx, &sg_dummy, 1,

	/* prepare transmit transfer */

	if (!rspi_dma_map_sg(&sg_tx, tx_buf, len, rspi->chan_tx,

			     DMA_TO_DEVICE))

		return -EFAULT;



	desc_tx = dmaengine_prep_slave_sg(rspi->chan_tx, &sg_tx, 1,

			DMA_TO_DEVICE, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);

	if (!desc_dummy) {

	if (!desc_tx) {

		ret = -EIO;

		goto end_dummy_mapped;

		goto end_tx_mapped;

	}



	/* prepare receive transfer */

	if (!rspi_dma_map_sg(&sg, rx_buf, len, rspi->chan_rx,

	if (!rspi_dma_map_sg(&sg_rx, rx_buf, len, rspi->chan_rx,

			     DMA_FROM_DEVICE)) {

		ret = -EFAULT;

		goto end_dummy_mapped;

		goto end_tx_mapped;



	}

	desc = dmaengine_prep_slave_sg(rspi->chan_rx, &sg, 1, DMA_FROM_DEVICE,

	desc_rx = dmaengine_prep_slave_sg(rspi->chan_rx, &sg_rx, 1,

					  DMA_FROM_DEVICE,

					  DMA_PREP_INTERRUPT | DMA_CTRL_ACK);

	if (!desc) {

	if (!desc_rx) {

		ret = -EIO;

		goto end;

	}
@@ -606,13 +601,13 @@ static int rspi_receive_dma(struct rspi_data *rspi, struct spi_transfer *t) 
	rspi_enable_irq(rspi, SPCR_SPTIE | SPCR_SPRIE);

	rspi->dma_callbacked = 0;



	desc->callback = rspi_dma_complete;

	desc->callback_param = rspi;

	dmaengine_submit(desc);

	desc_rx->callback = rspi_dma_complete;

	desc_rx->callback_param = rspi;

	dmaengine_submit(desc_rx);

	dma_async_issue_pending(rspi->chan_rx);



	desc_dummy->callback = NULL;	/* No callback */

	dmaengine_submit(desc_dummy);

	desc_tx->callback = NULL;	/* No callback */

	dmaengine_submit(desc_tx);

	dma_async_issue_pending(rspi->chan_tx);



	ret = wait_event_interruptible_timeout(rspi->wait,
@@ -628,21 +623,19 @@ static int rspi_receive_dma(struct rspi_data *rspi, struct spi_transfer *t) 
		enable_irq(rspi->rx_irq);



end:

	rspi_dma_unmap_sg(&sg, rspi->chan_rx, DMA_FROM_DEVICE);

end_dummy_mapped:

	rspi_dma_unmap_sg(&sg_dummy, rspi->chan_tx, DMA_TO_DEVICE);

end_nomap:

	kfree(dummy);



	rspi_dma_unmap_sg(&sg_rx, rspi->chan_rx, DMA_FROM_DEVICE);

end_tx_mapped:

	rspi_dma_unmap_sg(&sg_tx, rspi->chan_tx, DMA_TO_DEVICE);

	return ret;

}



static int rspi_is_dma(const struct rspi_data *rspi, struct spi_transfer *t)

{

	if (t->tx_buf && rspi->chan_tx)

		return 1;

	/* If the module receives data by DMAC, it also needs TX DMAC */

	if (t->rx_buf && rspi->chan_tx && rspi->chan_rx)

	if (t->rx_buf)

		return rspi->chan_tx && rspi->chan_rx;



	if (rspi->chan_tx)

		return 1;



	return 0;
@@ -654,7 +647,7 @@ static int rspi_transfer_out_in(struct rspi_data *rspi, 
	int remain = xfer->len, ret;

	const u8 *tx_buf = xfer->tx_buf;

	u8 *rx_buf = xfer->rx_buf;

	u8 spcr, data;

	u8 spcr;



	spcr = rspi_read8(rspi, RSPI_SPCR);

	if (rx_buf) {
@@ -666,8 +659,7 @@ static int rspi_transfer_out_in(struct rspi_data *rspi, 
	rspi_write8(rspi, spcr, RSPI_SPCR);



	while (remain > 0) {

		data = tx_buf ? *tx_buf++ : DUMMY_DATA;

		ret = rspi_data_out(rspi, data);

		ret = rspi_data_out(rspi, *tx_buf++);

		if (ret < 0)

			return ret;

		if (rx_buf) {
@@ -689,20 +681,14 @@ static int rspi_transfer_one(struct spi_master *master, struct spi_device *spi, 
			     struct spi_transfer *xfer)

{

	struct rspi_data *rspi = spi_master_get_devdata(master);

	int ret;



	if (!rspi_is_dma(rspi, xfer))

		return rspi_transfer_out_in(rspi, xfer);



	if (xfer->tx_buf) {

		ret = rspi_send_dma(rspi, xfer);

		if (ret < 0)

			return ret;

	}

	if (xfer->rx_buf)

		return rspi_receive_dma(rspi, xfer);



	return 0;

		return rspi_send_receive_dma(rspi, xfer);

	else

		return rspi_send_dma(rspi, xfer);

}



static int rspi_rz_transfer_out_in(struct rspi_data *rspi,
@@ -711,16 +697,13 @@ static int rspi_rz_transfer_out_in(struct rspi_data *rspi, 
	int remain = xfer->len, ret;

	const u8 *tx_buf = xfer->tx_buf;

	u8 *rx_buf = xfer->rx_buf;

	u8 data;



	rspi_rz_receive_init(rspi);



	while (remain > 0) {

		data = tx_buf ? *tx_buf++ : DUMMY_DATA;

		ret = rspi_data_out_in(rspi, data);

		ret = rspi_data_out_in(rspi, *tx_buf++);

		if (ret < 0)

			return ret;

		if (rx_buf)

		*rx_buf++ = ret;

		remain--;

	}
@@ -746,16 +729,13 @@ static int qspi_transfer_out_in(struct rspi_data *rspi, 
	int remain = xfer->len, ret;

	const u8 *tx_buf = xfer->tx_buf;

	u8 *rx_buf = xfer->rx_buf;

	u8 data;



	qspi_receive_init(rspi);



	while (remain > 0) {

		data = tx_buf ? *tx_buf++ : DUMMY_DATA;

		ret = rspi_data_out_in(rspi, data);

		ret = rspi_data_out_in(rspi, *tx_buf++);

		if (ret < 0)

			return ret;

		if (rx_buf)

		*rx_buf++ = ret;

		remain--;

	}
@@ -807,10 +787,10 @@ static int qspi_transfer_one(struct spi_master *master, struct spi_device *spi, 


	if (spi->mode & SPI_LOOP) {

		return qspi_transfer_out_in(rspi, xfer);

	} else if (xfer->tx_buf && xfer->tx_nbits > SPI_NBITS_SINGLE) {

	} else if (xfer->tx_nbits > SPI_NBITS_SINGLE) {

		/* Quad or Dual SPI Write */

		return qspi_transfer_out(rspi, xfer);

	} else if (xfer->rx_buf && xfer->rx_nbits > SPI_NBITS_SINGLE) {

	} else if (xfer->rx_nbits > SPI_NBITS_SINGLE) {

		/* Quad or Dual SPI Read */

		return qspi_transfer_in(rspi, xfer);

	} else {
@@ -1064,12 +1044,14 @@ static const struct spi_ops rspi_ops = { 
	.set_config_register =	rspi_set_config_register,

	.transfer_one =		rspi_transfer_one,

	.mode_bits =		SPI_CPHA | SPI_CPOL | SPI_LOOP,

	.flags =		SPI_MASTER_MUST_TX,

};



static const struct spi_ops rspi_rz_ops = {

	.set_config_register =	rspi_rz_set_config_register,

	.transfer_one =		rspi_rz_transfer_one,

	.mode_bits =		SPI_CPHA | SPI_CPOL | SPI_LOOP,

	.flags =		SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX,

};



static const struct spi_ops qspi_ops = {
@@ -1078,6 +1060,7 @@ static const struct spi_ops qspi_ops = { 
	.mode_bits =		SPI_CPHA | SPI_CPOL | SPI_LOOP |

				SPI_TX_DUAL | SPI_TX_QUAD |

				SPI_RX_DUAL | SPI_RX_QUAD,

	.flags =		SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX,

};



#ifdef CONFIG_OF
@@ -1197,6 +1180,7 @@ static int rspi_probe(struct platform_device *pdev) 
	master->prepare_message = rspi_prepare_message;

	master->unprepare_message = rspi_unprepare_message;

	master->mode_bits = ops->mode_bits;

	master->flags = ops->flags;

	master->dev.of_node = pdev->dev.of_node;



	ret = platform_get_irq_byname(pdev, "rx");