spi: cadence: Fix default polarity of native chipselect

The Cadence 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.

Fix this by inverting the logic in the callback for the
native chip select. Rename the parameter from "is_high"
(which is interpreted as being high when 0, which is
confusing, I will not make any drug-related jokes here)
to "enabled" which is more intuitive, especially now that
it is true when CS is supposed to be enabled.

Cc: Wei Yongjun <weiyongjun1@huawei.com>
Fixes: cfeefa79dc37 ("spi: cadence: Convert to use CS GPIO descriptors")
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NMark Brown <broonie@kernel.org>
Signed-off-by: NZou Cao <zoucao@linux.alibaba.com>
Reviewed-by: NBaoyou Xie <xie.baoyou@linux.alibaba.com>

drivers/spi/spi-cadence.c

@@ -172,16 +172,16 @@ 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
- * @is_high:	Select(0) or deselect (1) the chip select line
+ * @enable:	Select (1) or deselect (0) the chip select line
  */
-static void cdns_spi_chipselect(struct spi_device *spi, bool is_high)
+static void cdns_spi_chipselect(struct spi_device *spi, bool enable)
 {
 	struct cdns_spi *xspi = spi_master_get_devdata(spi->master);
 	u32 ctrl_reg;
 
 	ctrl_reg = cdns_spi_read(xspi, CDNS_SPI_CR);
 
-	if (is_high) {
+	if (!enable) {
 		/* Deselect the slave */
 		ctrl_reg |= CDNS_SPI_CR_SSCTRL;
 	} else {