Commit 7910d9af authored by Nicolas Ferre's avatar Nicolas Ferre Committed by Mark Brown
Browse files

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



We need both RX and TX data for each transfer in any case (PIO, PDC, DMA).
So convert the driver to the core dummy buffer handling with the
SPI_MASTER_MUST_RX/SPI_MASTER_MUST_TX infrastructure.

This move changes the maximum PDC/DMA buffer handling to 65535 bytes
instead of a single page and sets master->max_dma_len to this value.

All dummy buffer management is removed from the driver.

Signed-off-by: default avatarNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent ce24a513

drivers/spi/spi-atmel.c

+35 −96
Original line number Diff line number Diff line
@@ -303,10 +303,6 @@ struct atmel_spi { 


	struct completion	xfer_completion;



	/* scratch buffer */

	void			*buffer;

	dma_addr_t		buffer_dma;



	struct atmel_spi_caps	caps;



	bool			use_dma;
@@ -327,7 +323,7 @@ struct atmel_spi_device { 
	u32			csr;

};



#define BUFFER_SIZE		PAGE_SIZE

#define SPI_MAX_DMA_XFER	65535 /* true for both PDC and DMA */

#define INVALID_DMA_ADDRESS	0xffffffff



/*
@@ -612,14 +608,10 @@ static void atmel_spi_next_xfer_single(struct spi_master *master, 
		cpu_relax();

	}



	if (xfer->tx_buf) {

	if (xfer->bits_per_word > 8)

		spi_writel(as, TDR, *(u16 *)(xfer->tx_buf + xfer_pos));

	else

		spi_writel(as, TDR, *(u8 *)(xfer->tx_buf + xfer_pos));

	} else {

		spi_writel(as, TDR, 0);

	}



	dev_dbg(master->dev.parent,

		"  start pio xfer %p: len %u tx %p rx %p bitpw %d\n",
@@ -666,7 +658,6 @@ static void atmel_spi_next_xfer_fifo(struct spi_master *master, 


	/* Fill TX FIFO */

	while (num_data >= 2) {

		if (xfer->tx_buf) {

		if (xfer->bits_per_word > 8) {

			td0 = *words++;

			td1 = *words++;
@@ -674,24 +665,16 @@ static void atmel_spi_next_xfer_fifo(struct spi_master *master, 
			td0 = *bytes++;

			td1 = *bytes++;

		}

		} else {

			td0 = 0;

			td1 = 0;

		}



		spi_writel(as, TDR, (td1 << 16) | td0);

		num_data -= 2;

	}



	if (num_data) {

		if (xfer->tx_buf) {

		if (xfer->bits_per_word > 8)

			td0 = *words++;

		else

			td0 = *bytes++;

		} else {

			td0 = 0;

		}



		spi_writew(as, TDR, td0);

		num_data--;
@@ -750,24 +733,14 @@ static int atmel_spi_next_xfer_dma_submit(struct spi_master *master, 


	/* prepare the RX dma transfer */

	sg_init_table(&as->dma.sgrx, 1);

	if (xfer->rx_buf) {

	as->dma.sgrx.dma_address = xfer->rx_dma + xfer->len - *plen;

	} else {

		as->dma.sgrx.dma_address = as->buffer_dma;

		if (len > BUFFER_SIZE)

			len = BUFFER_SIZE;

	}



	/* prepare the TX dma transfer */

	sg_init_table(&as->dma.sgtx, 1);

	if (xfer->tx_buf) {

	as->dma.sgtx.dma_address = xfer->tx_dma + xfer->len - *plen;

	} else {

		as->dma.sgtx.dma_address = as->buffer_dma;

		if (len > BUFFER_SIZE)

			len = BUFFER_SIZE;

		memset(as->buffer, 0, len);

	}



	if (len > master->max_dma_len)

		len = master->max_dma_len;



	sg_dma_len(&as->dma.sgtx) = len;

	sg_dma_len(&as->dma.sgrx) = len;
@@ -834,25 +807,10 @@ static void atmel_spi_next_xfer_data(struct spi_master *master, 
	struct atmel_spi	*as = spi_master_get_devdata(master);

	u32			len = *plen;



	/* use scratch buffer only when rx or tx data is unspecified */

	if (xfer->rx_buf)

	*rx_dma = xfer->rx_dma + xfer->len - *plen;

	else {

		*rx_dma = as->buffer_dma;

		if (len > BUFFER_SIZE)

			len = BUFFER_SIZE;

	}



	if (xfer->tx_buf)

	*tx_dma = xfer->tx_dma + xfer->len - *plen;

	else {

		*tx_dma = as->buffer_dma;

		if (len > BUFFER_SIZE)

			len = BUFFER_SIZE;

		memset(as->buffer, 0, len);

		dma_sync_single_for_device(&as->pdev->dev,

				as->buffer_dma, len, DMA_TO_DEVICE);

	}

	if (len > master->max_dma_len)

		len = master->max_dma_len;



	*plen = len;

}
@@ -1026,7 +984,6 @@ atmel_spi_pump_single_data(struct atmel_spi *as, struct spi_transfer *xfer) 
	u16		*rxp16;

	unsigned long	xfer_pos = xfer->len - as->current_remaining_bytes;



	if (xfer->rx_buf) {

	if (xfer->bits_per_word > 8) {

		rxp16 = (u16 *)(((u8 *)xfer->rx_buf) + xfer_pos);

		*rxp16 = spi_readl(as, RDR);
@@ -1034,9 +991,6 @@ atmel_spi_pump_single_data(struct atmel_spi *as, struct spi_transfer *xfer) 
		rxp = ((u8 *)xfer->rx_buf) + xfer_pos;

		*rxp = spi_readl(as, RDR);

	}

	} else {

		spi_readl(as, RDR);

	}

	if (xfer->bits_per_word > 8) {

		if (as->current_remaining_bytes > 2)

			as->current_remaining_bytes -= 2;
@@ -1074,12 +1028,10 @@ atmel_spi_pump_fifo_data(struct atmel_spi *as, struct spi_transfer *xfer) 
	/* Read data */

	while (num_data) {

		rd = spi_readl(as, RDR);

		if (xfer->rx_buf) {

		if (xfer->bits_per_word > 8)

			*words++ = rd;

		else

			*bytes++ = rd;

		}

		num_data--;

	}

}
@@ -1561,29 +1513,22 @@ static int atmel_spi_probe(struct platform_device *pdev) 
	master->bus_num = pdev->id;

	master->num_chipselect = master->dev.of_node ? 0 : 4;

	master->setup = atmel_spi_setup;

	master->flags = (SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX);

	master->transfer_one_message = atmel_spi_transfer_one_message;

	master->cleanup = atmel_spi_cleanup;

	master->auto_runtime_pm = true;

	master->max_dma_len = SPI_MAX_DMA_XFER;

	platform_set_drvdata(pdev, master);



	as = spi_master_get_devdata(master);



	/*

	 * Scratch buffer is used for throwaway rx and tx data.

	 * It's coherent to minimize dcache pollution.

	 */

	as->buffer = dma_alloc_coherent(&pdev->dev, BUFFER_SIZE,

					&as->buffer_dma, GFP_KERNEL);

	if (!as->buffer)

		goto out_free;



	spin_lock_init(&as->lock);



	as->pdev = pdev;

	as->regs = devm_ioremap_resource(&pdev->dev, regs);

	if (IS_ERR(as->regs)) {

		ret = PTR_ERR(as->regs);

		goto out_free_buffer;

		goto out_unmap_regs;

	}

	as->phybase = regs->start;

	as->irq = irq;
@@ -1681,9 +1626,6 @@ out_free_dma: 
	clk_disable_unprepare(clk);

out_free_irq:

out_unmap_regs:

out_free_buffer:

	dma_free_coherent(&pdev->dev, BUFFER_SIZE, as->buffer,

			as->buffer_dma);

out_free:

	spi_master_put(master);

	return ret;
@@ -1708,9 +1650,6 @@ static int atmel_spi_remove(struct platform_device *pdev) 
	spi_readl(as, SR);

	spin_unlock_irq(&as->lock);



	dma_free_coherent(&pdev->dev, BUFFER_SIZE, as->buffer,

			as->buffer_dma);



	clk_disable_unprepare(as->clk);



	pm_runtime_put_noidle(&pdev->dev);

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