From: Charles Keepax ckeepax@opensource.cirrus.com
[ Upstream commit 61acd19f9c56fa0809285346bd0bd4a926ab0da0 ]
To fix a regression on the Cadence SPI driver, this patch reverts commit 6046f5407ff0 ("spi: cadence: Fix default polarity of native chipselect").
This patch was not the correct fix for the issue. The SPI framework calls the set_cs line with the logic level it desires on the chip select line, as such the old is_high handling was correct. However, this was broken by the fact that before commit 3e5ec1db8bfe ("spi: Fix SPI_CS_HIGH setting when using native and GPIO CS") all controllers that offered the use of a GPIO chip select had SPI_CS_HIGH applied, even for hardware chip selects. This caused the value passed into the driver to be inverted. Which unfortunately makes it look like a logical enable the chip select value.
Since the core was corrected to not unconditionally apply SPI_CS_HIGH, the Cadence driver, whilst using the hardware chip select, will deselect the chip select every time we attempt to communicate with the device, which results in failed communications.
Fixes: 3e5ec1db8bfe ("spi: Fix SPI_CS_HIGH setting when using native and GPIO CS") Signed-off-by: Charles Keepax ckeepax@opensource.cirrus.com Acked-by: Linus Walleij linus.walleij@linaro.org Link: https://lore.kernel.org/r/20191126164140.6240-1-ckeepax@opensource.cirrus.co... Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/spi/spi-cadence.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/spi/spi-cadence.c b/drivers/spi/spi-cadence.c index c36587b42e95..82a0ee09cbe1 100644 --- a/drivers/spi/spi-cadence.c +++ b/drivers/spi/spi-cadence.c @@ -168,16 +168,16 @@ static void cdns_spi_init_hw(struct cdns_spi *xspi) /** * cdns_spi_chipselect - Select or deselect the chip select line * @spi: Pointer to the spi_device structure - * @enable: Select (1) or deselect (0) the chip select line + * @is_high: Select(0) or deselect (1) the chip select line */ -static void cdns_spi_chipselect(struct spi_device *spi, bool enable) +static void cdns_spi_chipselect(struct spi_device *spi, bool is_high) { struct cdns_spi *xspi = spi_master_get_devdata(spi->master); u32 ctrl_reg;
ctrl_reg = cdns_spi_read(xspi, CDNS_SPI_CR);
- if (!enable) { + if (is_high) { /* Deselect the slave */ ctrl_reg |= CDNS_SPI_CR_SSCTRL; } else {