[PATCH 2/3] spi: spi-imx: set max_native_cs for imx51/imx53/imx6 variants

[Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>]

The ecspi IP block on imx51/imx53/imx6 have four native chip
selects. Tell that to the spi core so that any non-gpio chip selects
get validated against that upper bound.

Also set the SPI_MASTER_GPIO_SS so that the core verifies that, in the
case where both native and gpio chip selects are in use, there is at
least one leftover native chip select (or "channel", in the ecspi
language) for use by the slaves sitting on gpio chip selects.

Signed-off-by: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
---
 drivers/spi/spi-imx.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
index 6fa53a82674a..e8f7afbd9847 100644
--- a/drivers/spi/spi-imx.c
+++ b/drivers/spi/spi-imx.c
@@ -1749,6 +1749,11 @@ static int spi_imx_probe(struct platform_device *pdev)
 		 */
 		controller->mode_bits |= SPI_CS_WORD;
 
+	if (is_imx51_ecspi(spi_imx) || is_imx53_ecspi(spi_imx)) {
+		controller->max_native_cs = 4;
+		controller->flags |= SPI_MASTER_GPIO_SS;
+	}
+
 	spi_imx->spi_drctl = spi_drctl;
 
 	init_completion(&spi_imx->xfer_done);
-- 
2.37.2