Unverified Commit 79422ed9 authored by Baruch Siach's avatar Baruch Siach Committed by Mark Brown
Browse files

spi: spi-imx: add support for SPI_RX_CPHA_FLIP 



When SPI_RX_CPHA_FLIP is set, flip CPHA on Rx only transfers. This is
useful to access devices that use inverted CPHA for MISO vs MOSI
signals.

Only support the mx51/mx53 variants for now.

Tested on i.MX6ULL based system.

Signed-off-by: default avatarBaruch Siach <baruch.siach@siklu.com>
Link: https://lore.kernel.org/r/e11b4446afe9a46a282dd923d22c27d03fae15f8.1649702729.git.baruch@tkos.co.il


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 178d0cbb

drivers/spi/spi-imx.c

+27 −5
Original line number Diff line number Diff line
@@ -108,6 +108,7 @@ struct spi_imx_data { 
	const void *tx_buf;

	unsigned int txfifo; /* number of words pushed in tx FIFO */

	unsigned int dynamic_burst;

	bool rx_only;



	/* Slave mode */

	bool slave_mode;
@@ -554,11 +555,6 @@ static int mx51_ecspi_prepare_message(struct spi_imx_data *spi_imx, 
	else

		cfg |= MX51_ECSPI_CONFIG_SBBCTRL(spi->chip_select);



	if (spi->mode & SPI_CPHA)

		cfg |= MX51_ECSPI_CONFIG_SCLKPHA(spi->chip_select);

	else

		cfg &= ~MX51_ECSPI_CONFIG_SCLKPHA(spi->chip_select);



	if (spi->mode & SPI_CPOL) {

		cfg |= MX51_ECSPI_CONFIG_SCLKPOL(spi->chip_select);

		cfg |= MX51_ECSPI_CONFIG_SCLKCTL(spi->chip_select);
@@ -606,6 +602,24 @@ static int mx51_ecspi_prepare_message(struct spi_imx_data *spi_imx, 
	return 0;

}



static void mx51_configure_cpha(struct spi_imx_data *spi_imx,

				struct spi_device *spi)

{

	bool cpha = (spi->mode & SPI_CPHA);

	bool flip_cpha = (spi->mode & SPI_RX_CPHA_FLIP) && spi_imx->rx_only;

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



	/* Flip cpha logical value iff flip_cpha */

	cpha ^= flip_cpha;



	if (cpha)

		cfg |= MX51_ECSPI_CONFIG_SCLKPHA(spi->chip_select);

	else

		cfg &= ~MX51_ECSPI_CONFIG_SCLKPHA(spi->chip_select);



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

}



static int mx51_ecspi_prepare_transfer(struct spi_imx_data *spi_imx,

				       struct spi_device *spi)

{
@@ -627,6 +641,8 @@ static int mx51_ecspi_prepare_transfer(struct spi_imx_data *spi_imx, 
	ctrl |= mx51_ecspi_clkdiv(spi_imx, spi_imx->spi_bus_clk, &clk);

	spi_imx->spi_bus_clk = clk;



	mx51_configure_cpha(spi_imx, spi);



	/*

	 * ERR009165: work in XHC mode instead of SMC as PIO on the chips

	 * before i.mx6ul.
@@ -1251,6 +1267,9 @@ static int spi_imx_setupxfer(struct spi_device *spi, 
	else

		spi_imx->usedma = false;



	spi_imx->rx_only = ((t->tx_buf == NULL)

			|| (t->tx_buf == spi->controller->dummy_tx));



	if (is_imx53_ecspi(spi_imx) && spi_imx->slave_mode) {

		spi_imx->rx = mx53_ecspi_rx_slave;

		spi_imx->tx = mx53_ecspi_tx_slave;
@@ -1655,6 +1674,9 @@ static int spi_imx_probe(struct platform_device *pdev) 
	    is_imx53_ecspi(spi_imx))

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



	if (is_imx51_ecspi(spi_imx) || is_imx53_ecspi(spi_imx))

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



	if (is_imx51_ecspi(spi_imx) &&

	    device_property_read_u32(&pdev->dev, "cs-gpios", NULL))

		/*