Commit 16779622 authored by H Hartley Sweeten's avatar H Hartley Sweeten Committed by Mark Brown
Browse files

spi: spi-ep93xx: add spi master prepare_transfer_hardware() 



This driver currently enables the hardware at the start of every
message and disabled it when the message is complete. Make it a
bit smarter by adding the prepare_transfer_hardware() and
unprepare_transfer_hardware() callbacks so that the core can
enable/disable the hardware based on spi message queue.

Signed-off-by: default avatarH Hartley Sweeten <hsweeten@visionengravers.com>
[chris: use u32 instead of unsigned int]
Signed-off-by: default avatarChris Packham <chris.packham@alliedtelesis.co.nz>
Reviewed-by: default avatarAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 8447e478

drivers/spi/spi-ep93xx.c

+33 −39
Original line number Diff line number Diff line
@@ -111,33 +111,6 @@ struct ep93xx_spi { 
/* converts bits per word to CR0.DSS value */

#define bits_per_word_to_dss(bpw)	((bpw) - 1)



static int ep93xx_spi_enable(const struct ep93xx_spi *espi)

{

	u32 val;

	int err;



	err = clk_enable(espi->clk);

	if (err)

		return err;



	val = readl(espi->mmio + SSPCR1);

	val |= SSPCR1_SSE;

	writel(val, espi->mmio + SSPCR1);



	return 0;

}



static void ep93xx_spi_disable(const struct ep93xx_spi *espi)

{

	u32 val;



	val = readl(espi->mmio + SSPCR1);

	val &= ~SSPCR1_SSE;

	writel(val, espi->mmio + SSPCR1);



	clk_disable(espi->clk);

}



static void ep93xx_spi_enable_interrupts(const struct ep93xx_spi *espi)

{

	u32 val;
@@ -571,17 +544,6 @@ static void ep93xx_spi_process_message(struct ep93xx_spi *espi, 
{

	unsigned long timeout;

	struct spi_transfer *t;

	int err;



	/*

	 * Enable the SPI controller and its clock.

	 */

	err = ep93xx_spi_enable(espi);

	if (err) {

		dev_err(&espi->pdev->dev, "failed to enable SPI controller\n");

		msg->status = err;

		return;

	}



	/*

	 * Just to be sure: flush any data from RX FIFO.
@@ -619,7 +581,6 @@ static void ep93xx_spi_process_message(struct ep93xx_spi *espi, 
	 * deselect the device and disable the SPI controller.

	 */

	ep93xx_spi_cs_control(msg->spi, false);

	ep93xx_spi_disable(espi);

}



static int ep93xx_spi_transfer_one_message(struct spi_master *master,
@@ -679,6 +640,37 @@ static irqreturn_t ep93xx_spi_interrupt(int irq, void *dev_id) 
	return IRQ_HANDLED;

}



static int ep93xx_spi_prepare_hardware(struct spi_master *master)

{

	struct ep93xx_spi *espi = spi_master_get_devdata(master);

	u32 val;

	int ret;



	ret = clk_enable(espi->clk);

	if (ret)

		return ret;



	val = readl(espi->mmio + SSPCR1);

	val |= SSPCR1_SSE;

	writel(val, espi->mmio + SSPCR1);



	return 0;

}



static int ep93xx_spi_unprepare_hardware(struct spi_master *master)

{

	struct ep93xx_spi *espi = spi_master_get_devdata(master);

	u32 val;



	val = readl(espi->mmio + SSPCR1);

	val &= ~SSPCR1_SSE;

	writel(val, espi->mmio + SSPCR1);



	clk_disable(espi->clk);



	return 0;

}



static bool ep93xx_spi_dma_filter(struct dma_chan *chan, void *filter_param)

{

	if (ep93xx_dma_chan_is_m2p(chan))
@@ -780,6 +772,8 @@ static int ep93xx_spi_probe(struct platform_device *pdev) 
	if (!master)

		return -ENOMEM;



	master->prepare_transfer_hardware = ep93xx_spi_prepare_hardware;

	master->unprepare_transfer_hardware = ep93xx_spi_unprepare_hardware;

	master->transfer_one_message = ep93xx_spi_transfer_one_message;

	master->bus_num = pdev->id;

	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;

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