Unverified Commit ccd978b7 authored Mar 30, 2019 by Martin Sperl Committed by Mark Brown Apr 03, 2019

spi: bcm2835aux: setup gpio-cs to output and correct level during setup



Setup gpio-cs to the correct levels during setup and also make the
gpio definitely an output GPIO.

This is transparently fixing some badly configured DTs in the process
where cs-gpio is set but the gpios are still configured with native cs.

It also makes 100% sure that the initial CS levels are as expected -
especially on systems with devices on a bus with mixed CS_HIGH/CS_LOW
settings.

Fixes: 1ea29b39 ("spi: bcm2835aux: add bcm2835 auxiliary spi device...")
Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Acked-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

parent 519f2c22

drivers/spi/spi-bcm2835aux.c

+14 −2

Original line number	Diff line number	Diff line
		@@ -403,8 +403,20 @@ static int bcm2835aux_spi_setup(struct spi_device *spi)
		/* sanity check for native cs */
		if (spi->mode & SPI_NO_CS)
		return 0;
		if (gpio_is_valid(spi->cs_gpio))
		return 0;
		if (gpio_is_valid(spi->cs_gpio)) {
		/* with gpio-cs set the GPIO to the correct level
		* and as output (in case the dt has the gpio not configured
		* as output but native cs)
		*/
		ret = gpio_direction_output(spi->cs_gpio,
		(spi->mode & SPI_CS_HIGH) ? 0 : 1);
		if (ret)
		dev_err(&spi->dev,
		"could not set gpio %i as output: %i\n",
		spi->cs_gpio, ret);

		return ret;
		}

		/* for dt-backwards compatibility: only support native on CS0
		* known things not supported with broken native CS:

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