Unverified Commit 6e95b23a authored by Uwe Kleine-König's avatar Uwe Kleine-König Committed by Mark Brown
Browse files

spi: imx: Implement support for CS_WORD 



This only works when the native chipselect is in use. On a board with a
Ti ADS7950 8 channel ADC. This patch reduces the time to read out all
channels once from 280 us to 20 us.

Signed-off-by: default avatarUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20210727124226.5571-1-u.kleine-koenig@pengutronix.de


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent e3aa9acc

drivers/spi/spi-imx.c

+10 −0
Original line number Diff line number Diff line
@@ -1176,6 +1176,7 @@ static int spi_imx_setupxfer(struct spi_device *spi, 
	 * dynamic_burst in that case.

	 */

	if (spi_imx->devtype_data->dynamic_burst && !spi_imx->slave_mode &&

	    !(spi->mode & SPI_CS_WORD) &&

	    (spi_imx->bits_per_word == 8 ||

	    spi_imx->bits_per_word == 16 ||

	    spi_imx->bits_per_word == 32)) {
@@ -1611,6 +1612,15 @@ 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) &&

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

		/*

		 * When using HW-CS implementing SPI_CS_WORD can be done by just

		 * setting the burst length to the word size. This is

		 * considerably faster than manually controlling the CS.

		 */

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



	spi_imx->spi_drctl = spi_drctl;



	init_completion(&spi_imx->xfer_done);