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[V2,7/9] spi: bcm2835aux: setup gpio-cs to output and correct level during setup

Message ID 20190324175002.28969-8-kernel@martin.sperl.org (mailing list archive)
State New, archived
Headers show
Series spi: bcm2835aux: bug fixes and improvements | expand

Commit Message

Martin Sperl March 24, 2019, 5:50 p.m. UTC 
From: Martin Sperl <kernel@martin.sperl.org>

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: 1ea29b39f4c812ece2f936065a0a3d6fe44a263e
Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
---
 drivers/spi/spi-bcm2835aux.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

--
2.11.0
diff mbox series

Patch

diff --git a/drivers/spi/spi-bcm2835aux.c b/drivers/spi/spi-bcm2835aux.c
index 6af07dec5fdc..dd0446968da6 100644
--- a/drivers/spi/spi-bcm2835aux.c
+++ b/drivers/spi/spi-bcm2835aux.c
@@ -425,7 +425,17 @@  static int bcm2835aux_spi_setup(struct spi_device *spi)
 		return -EINVAL;
 	}

-	return 0;
+	/* 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;
 }

 static int bcm2835aux_spi_probe(struct platform_device *pdev)