[PATCH 06/13] spi: spi-fsl-lpspi: Add DT property to override default pin config

[James Clark]

This allows the SIN and SOUT pins to be flipped. Use an enum instead of
a bool even though we only support 2 modes so that the other two half
duplex modes can also be used in the future, if the driver ever supports
them.

If no property is specified, continue with the old defaults.

Signed-off-by: James Clark <james.clark@xxxxxxxxxx>
---
 drivers/spi/spi-fsl-lpspi.c | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/drivers/spi/spi-fsl-lpspi.c b/drivers/spi/spi-fsl-lpspi.c
index 816e48bbc810..98da6a5d7013 100644
--- a/drivers/spi/spi-fsl-lpspi.c
+++ b/drivers/spi/spi-fsl-lpspi.c
@@ -88,6 +88,13 @@
 
 #define SR_CLEAR_MASK	GENMASK(13, 8)
 
+static const char * const pincfgs[] = {
+	[CFGR1_PINCFG_SIN_IN_SOUT_OUT] = "sin-in-sout-out",
+	[CFGR1_PINCFG_SIN_ONLY] = "sin-only",
+	[CFGR1_PINCFG_SOUT_ONLY] = "sout-only",
+	[CFGR1_PINCFG_SOUT_IN_SIN_OUT] = "sout-in-sin-out",
+};
+
 struct fsl_lpspi_devtype_data {
 	u8 prescale_max;
 };
@@ -417,18 +424,27 @@ static int fsl_lpspi_config(struct fsl_lpspi_data *fsl_lpspi)
 {
 	u32 temp = 0;
 	int ret;
+	const char *pincfg_str;
 	u8 pincfg;
 
 	if (!fsl_lpspi->is_target) {
 		ret = fsl_lpspi_set_bitrate(fsl_lpspi);
 		if (ret)
 			return ret;
+
+		temp |= CFGR1_HOST;
 	}
 
 	fsl_lpspi_set_watermark(fsl_lpspi);
 
-	if (!fsl_lpspi->is_target) {
-		temp |= CFGR1_HOST;
+	if (!of_property_read_string(fsl_lpspi->dev->of_node,
+				     "nxp,lpspi-pincfg", &pincfg_str)) {
+		pincfg = match_string(pincfgs, ARRAY_SIZE(pincfgs), pincfg_str);
+
+		if (pincfg < 0 || pincfg == CFGR1_PINCFG_SOUT_ONLY ||
+		    pincfg == CFGR1_PINCFG_SIN_ONLY)
+			return -EINVAL;
+	} else if (!fsl_lpspi->is_target) {
 		pincfg = CFGR1_PINCFG_SIN_IN_SOUT_OUT;
 	} else {
 		pincfg = CFGR1_PINCFG_SOUT_IN_SIN_OUT;

-- 
2.34.1