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Commit 089651ef authored by Uwe Kleine-König's avatar Uwe Kleine-König Committed by Greg Kroah-Hartman
Browse files

spi: imx: mx51-ecspi: Move some initialisation to prepare_message hook. 



The relevant difference between prepare_message and config is that the
former is run before the CS signal is asserted. So the polarity of the
CLK line must be configured in prepare_message as an edge generated by
config might already result in a latch of the MOSI line.

Signed-off-by: default avatarUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
[ukleinek: backport to v4.14.x]
Signed-off-by: default avatarUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 0cc6feb5

drivers/spi/spi-imx.c

+36 −23
Original line number Diff line number Diff line
@@ -443,14 +443,9 @@ static void mx51_ecspi_trigger(struct spi_imx_data *spi_imx) 
static int mx51_ecspi_prepare_message(struct spi_imx_data *spi_imx,

				      struct spi_message *msg)

{

	return 0;

}



static int mx51_ecspi_config(struct spi_device *spi)

{

	struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);

	struct spi_device *spi = msg->spi;

	u32 ctrl = MX51_ECSPI_CTRL_ENABLE;

	u32 clk = spi_imx->speed_hz, delay, reg;

	u32 testreg;

	u32 cfg = readl(spi_imx->base + MX51_ECSPI_CONFIG);



	/*
@@ -468,14 +463,21 @@ static int mx51_ecspi_config(struct spi_device *spi) 
	if (spi->mode & SPI_READY)

		ctrl |= MX51_ECSPI_CTRL_DRCTL(spi_imx->spi_drctl);



	/* set clock speed */

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

	spi_imx->spi_bus_clk = clk;



	/* set chip select to use */

	ctrl |= MX51_ECSPI_CTRL_CS(spi->chip_select);



	ctrl |= (spi_imx->bits_per_word - 1) << MX51_ECSPI_CTRL_BL_OFFSET;

	/*

	 * The ctrl register must be written first, with the EN bit set other

	 * registers must not be written to.

	 */

	writel(ctrl, spi_imx->base + MX51_ECSPI_CTRL);



	testreg = readl(spi_imx->base + MX51_ECSPI_TESTREG);

	if (spi->mode & SPI_LOOP)

		testreg |= MX51_ECSPI_TESTREG_LBC;

	else

		testreg &= ~MX51_ECSPI_TESTREG_LBC;

	writel(testreg, spi_imx->base + MX51_ECSPI_TESTREG);



	cfg |= MX51_ECSPI_CONFIG_SBBCTRL(spi->chip_select);
@@ -491,26 +493,38 @@ static int mx51_ecspi_config(struct spi_device *spi) 
		cfg &= ~MX51_ECSPI_CONFIG_SCLKPOL(spi->chip_select);

		cfg &= ~MX51_ECSPI_CONFIG_SCLKCTL(spi->chip_select);

	}



	if (spi->mode & SPI_CS_HIGH)

		cfg |= MX51_ECSPI_CONFIG_SSBPOL(spi->chip_select);

	else

		cfg &= ~MX51_ECSPI_CONFIG_SSBPOL(spi->chip_select);



	writel(cfg, spi_imx->base + MX51_ECSPI_CONFIG);



	return 0;

}



static int mx51_ecspi_config(struct spi_device *spi)

{

	struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);

	u32 ctrl = readl(spi_imx->base + MX51_ECSPI_CTRL);

	u32 clk = spi_imx->speed_hz, delay;



	/* Clear BL field and set the right value */

	ctrl &= ~MX51_ECSPI_CTRL_BL_MASK;

	ctrl |= (spi_imx->bits_per_word - 1) << MX51_ECSPI_CTRL_BL_OFFSET;



	/* set clock speed */

	ctrl &= ~(0xf << MX51_ECSPI_CTRL_POSTDIV_OFFSET |

		  0xf << MX51_ECSPI_CTRL_PREDIV_OFFSET);

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

	spi_imx->spi_bus_clk = clk;



	if (spi_imx->usedma)

		ctrl |= MX51_ECSPI_CTRL_SMC;



	/* CTRL register always go first to bring out controller from reset */

	writel(ctrl, spi_imx->base + MX51_ECSPI_CTRL);



	reg = readl(spi_imx->base + MX51_ECSPI_TESTREG);

	if (spi->mode & SPI_LOOP)

		reg |= MX51_ECSPI_TESTREG_LBC;

	else

		reg &= ~MX51_ECSPI_TESTREG_LBC;

	writel(reg, spi_imx->base + MX51_ECSPI_TESTREG);



	writel(cfg, spi_imx->base + MX51_ECSPI_CONFIG);



	/*

	 * Wait until the changes in the configuration register CONFIGREG

	 * propagate into the hardware. It takes exactly one tick of the
@@ -532,7 +546,6 @@ static int mx51_ecspi_config(struct spi_device *spi) 
	 * Configure the DMA register: setup the watermark

	 * and enable DMA request.

	 */



	writel(MX51_ECSPI_DMA_RX_WML(spi_imx->wml) |

		MX51_ECSPI_DMA_TX_WML(spi_imx->wml) |

		MX51_ECSPI_DMA_RXT_WML(spi_imx->wml) |