[PATCH 5/6] spi: dw: Fix default polarity of native chipselect

Ike Panhc ike.pan at canonical.com
Mon May 6 09:20:28 UTC 2019

From: Linus Walleij <linus.walleij at linaro.org>

BugLink: https://bugs.launchpad.net/bugs/1826142

The DW controller also supports platforms specifying
native chipselects. When I enforce the use of high CS
for drivers opting in for using GPIO descriptors, I
inadvertedly switched the driver to also use active
high chip select for native chip selects.

As it turns out, the DW hardware driving chip selects
also thinks it is weird with active low chip selects
so all we need to do is remove an inversion in the

Cc: Jan Kotas <jank at cadence.com>
Reported-by: Jan Kotas <jank at cadence.com>
Tested-by: Jan Kotas <jank at cadence.com>
Fixes: 9400c41e77b8 ("spi: dw: Convert to use CS GPIO descriptors")
Signed-off-by: Linus Walleij <linus.walleij at linaro.org>
Signed-off-by: Mark Brown <broonie at kernel.org>
(cherry picked from commit 6e0a32d6f376ea22a34ae3a8df60adafbcdb0c86)
Signed-off-by: Ike Panhc <ike.pan at canonical.com>
 drivers/spi/spi-dw.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/spi/spi-dw.c b/drivers/spi/spi-dw.c
index cb79ac41ae8d..1a7386eec36d 100644
--- a/drivers/spi/spi-dw.c
+++ b/drivers/spi/spi-dw.c
@@ -137,11 +137,10 @@ void dw_spi_set_cs(struct spi_device *spi, bool enable)
 	struct dw_spi *dws = spi_controller_get_devdata(spi->controller);
 	struct chip_data *chip = spi_get_ctldata(spi);
-	/* Chip select logic is inverted from spi_set_cs() */
 	if (chip && chip->cs_control)
-		chip->cs_control(!enable);
+		chip->cs_control(enable);
-	if (!enable)
+	if (enable)
 		dw_writel(dws, DW_SPI_SER, BIT(spi->chip_select));
 	else if (dws->cs_override)
 		dw_writel(dws, DW_SPI_SER, 0);

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