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spi: dw: Fix default polarity of native chipselect 

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
driver.

Cc: Jan Kotas <jank@cadence.com>
Reported-by: Jan Kotas <jank@cadence.com>
Tested-by: Jan Kotas <jank@cadence.com>
Fixes: 9400c41e77 ("spi: dw: Convert to use CS GPIO descriptors")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Linus Walleij 2019-01-16 09:21:08 +01:00 committed by Mark Brown
parent 2df201e006
commit 6e0a32d6f3
No known key found for this signature in database
GPG Key ID: 24D68B725D5487D0
1 changed files with 2 additions and 3 deletions
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5
drivers/spi/spi-dw.c
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@ -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);