spi: always use software fallback for SPI_CS_WORD when using cs_gio

This modifies the condition for using the software fallback
implementation for SPI_CS_WORD when the SPI controller is using a GPIO
for the CS line. When using a GPIO for CS, the hardware implementation
won't work, so we just enable the software fallback globally in this
case.
Signed-off-by: David Lechner <david@lechnology.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi.c

@@ -2832,11 +2832,13 @@ static int __spi_validate(struct spi_device *spi, struct spi_message *message)
 		return -EINVAL;
 
 	/* If an SPI controller does not support toggling the CS line on each
-	 * transfer (indicated by the SPI_CS_WORD flag), we can emulate it by
+	 * transfer (indicated by the SPI_CS_WORD flag) or we are using a GPIO
+	 * for the CS line, we can emulate the CS-per-word hardware function by
 	 * splitting transfers into one-word transfers and ensuring that
 	 * cs_change is set for each transfer.
 	 */
-	if ((spi->mode & SPI_CS_WORD) && !(ctlr->mode_bits & SPI_CS_WORD)) {
+	if ((spi->mode & SPI_CS_WORD) && (!(ctlr->mode_bits & SPI_CS_WORD) ||
+					  gpio_is_valid(spi->cs_gpio))) {
 		size_t maxsize;
 		int ret;