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: 1ea29b39f4c812ec ("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>

diff --git a/drivers/spi/spi-bcm2835aux.c b/drivers/spi/spi-bcm2835aux.c
index a105db37141765a3e59aa0d29b0e1a1c65450478..99414319001ac3fe66dfc93043195379bde0c80b 100644 (file)
--- a/drivers/spi/spi-bcm2835aux.c
+++ b/drivers/spi/spi-bcm2835aux.c
@@ -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: