[PATCH] spi: spi-fsl-lpspi: Fix off-by-one in prescale max

[Stefan Wahren <wahrenst@gmx.net>]

The commit 783bf5d09f86 ("spi: spi-fsl-lpspi: limit PRESCALE bit in
TCR register") doesn't implement the prescaler maximum as intended.
The maximum allowed value for i.MX93 should be 1 and for i.MX7ULP
it should be 7. So this needs also a adjustment of the comparison
in the scldiv calculation.

Fixes: 783bf5d09f86 ("spi: spi-fsl-lpspi: limit PRESCALE bit in TCR register")
Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
---
 drivers/spi/spi-fsl-lpspi.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/spi/spi-fsl-lpspi.c b/drivers/spi/spi-fsl-lpspi.c
index 350c5d91d869..8ecb426be45c 100644
--- a/drivers/spi/spi-fsl-lpspi.c
+++ b/drivers/spi/spi-fsl-lpspi.c
@@ -136,7 +136,7 @@ static struct fsl_lpspi_devtype_data imx93_lpspi_devtype_data = {
 };

 static struct fsl_lpspi_devtype_data imx7ulp_lpspi_devtype_data = {
-	.prescale_max = 8,
+	.prescale_max = 7,
 };

 static const struct of_device_id fsl_lpspi_dt_ids[] = {
@@ -336,7 +336,7 @@ static int fsl_lpspi_set_bitrate(struct fsl_lpspi_data *fsl_lpspi)

 	div = DIV_ROUND_UP(perclk_rate, config.speed_hz);

-	for (prescale = 0; prescale < prescale_max; prescale++) {
+	for (prescale = 0; prescale <= prescale_max; prescale++) {
 		scldiv = div / (1 << prescale) - 2;
 		if (scldiv < 256) {
 			fsl_lpspi->config.prescale = prescale;
--
2.34.1