From ccd978b708b03b18196205b3baee83b5047ee453 Mon Sep 17 00:00:00 2001
From: Martin Sperl <kernel@martin.sperl.org>
Date: Sat, 30 Mar 2019 09:31:04 +0000
Subject: [PATCH] spi: bcm2835aux: setup gpio-cs to output and correct level during setup
Git-commit: ccd978b708b03b18196205b3baee83b5047ee453
Patch-mainline: v5.2-rc1
References: bsc#1051510
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>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/spi/spi-bcm2835aux.c | 16 ++++++++++++++--
1 file changed, 14 insertions(+), 2 deletions(-)
diff --git a/drivers/spi/spi-bcm2835aux.c b/drivers/spi/spi-bcm2835aux.c
index a105db371417..99414319001a 100644
--- 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:
--
2.16.4