Commit f72efa7e authored by Leif Middelschulte's avatar Leif Middelschulte Committed by Mark Brown
Browse files

spi-imx: Implements handling of the SPI_READY mode flag. 



This patch implements consideration of the SPI_READY mode flag as
defined in spi.h. It extends the device tree bindings to support
the values defined by the reference manual for the DRCTL field.

Thus supporting edge-triggered and level-triggered bursts.

Signed-off-by: default avatarLeif Middelschulte <Leif.Middelschulte@gmail.com>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent c1ae3cfa

Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt

+7 −0
Original line number Diff line number Diff line
@@ -23,6 +23,12 @@ See the clock consumer binding, 
Obsolete properties:

- fsl,spi-num-chipselects : Contains the number of the chipselect



Optional properties:

- fsl,spi-rdy-drctl: Integer, representing the value of DRCTL, the register

controlling the SPI_READY handling. Note that to enable the DRCTL consideration,

the SPI_READY mode-flag needs to be set too.

Valid values are: 0 (disabled), 1 (edge-triggered burst) and 2 (level-triggered burst).



Example:



ecspi@70010000 {
@@ -35,4 +41,5 @@ ecspi@70010000 { 
		   <&gpio3 25 0>; /* GPIO3_25 */

	dmas = <&sdma 3 7 1>, <&sdma 4 7 2>;

	dma-names = "rx", "tx";

	fsl,spi-rdy-drctl = <1>;

};

drivers/spi/spi-imx.c

+18 −2
Original line number Diff line number Diff line
@@ -95,6 +95,7 @@ struct spi_imx_data { 
	unsigned int spi_bus_clk;



	unsigned int bytes_per_word;

	unsigned int spi_drctl;



	unsigned int count;

	void (*tx)(struct spi_imx_data *);
@@ -246,6 +247,7 @@ static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi, 
#define MX51_ECSPI_CTRL_XCH		(1 <<  2)

#define MX51_ECSPI_CTRL_SMC		(1 << 3)

#define MX51_ECSPI_CTRL_MODE_MASK	(0xf << 4)

#define MX51_ECSPI_CTRL_DRCTL(drctl)	((drctl) << 16)

#define MX51_ECSPI_CTRL_POSTDIV_OFFSET	8

#define MX51_ECSPI_CTRL_PREDIV_OFFSET	12

#define MX51_ECSPI_CTRL_CS(cs)		((cs) << 18)
@@ -355,6 +357,12 @@ static int mx51_ecspi_config(struct spi_device *spi, 
	 */

	ctrl |= MX51_ECSPI_CTRL_MODE_MASK;



	/*

	 * Enable SPI_RDY handling (falling edge/level triggered).

	 */

	if (spi->mode & SPI_READY)

		ctrl |= MX51_ECSPI_CTRL_DRCTL(spi_imx->spi_drctl);



	/* set clock speed */

	ctrl |= mx51_ecspi_clkdiv(spi_imx, config->speed_hz, &clk);

	spi_imx->spi_bus_clk = clk;
@@ -1173,7 +1181,7 @@ static int spi_imx_probe(struct platform_device *pdev) 
	struct spi_master *master;

	struct spi_imx_data *spi_imx;

	struct resource *res;

	int i, ret, irq;

	int i, ret, irq, spi_drctl;



	if (!np && !mxc_platform_info) {

		dev_err(&pdev->dev, "can't get the platform data\n");
@@ -1181,6 +1189,12 @@ static int spi_imx_probe(struct platform_device *pdev) 
	}



	master = spi_alloc_master(&pdev->dev, sizeof(struct spi_imx_data));

	ret = of_property_read_u32(np, "fsl,spi-rdy-drctl", &spi_drctl);

	if ((ret < 0) || (spi_drctl >= 0x3)) {

		/* '11' is reserved */

		spi_drctl = 0;

	}



	if (!master)

		return -ENOMEM;
@@ -1216,7 +1230,9 @@ static int spi_imx_probe(struct platform_device *pdev) 
	spi_imx->bitbang.master->unprepare_message = spi_imx_unprepare_message;

	spi_imx->bitbang.master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;

	if (is_imx35_cspi(spi_imx) || is_imx51_ecspi(spi_imx))

		spi_imx->bitbang.master->mode_bits |= SPI_LOOP;

		spi_imx->bitbang.master->mode_bits |= SPI_LOOP | SPI_READY;



	spi_imx->spi_drctl = spi_drctl;



	init_completion(&spi_imx->xfer_done);

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