From: Stefan Wahren <wahrenst@gmx.net>
Date: Thu, 5 Sep 2024 11:15:37 +0000 (+0200)
Subject: spi: spi-fsl-lpspi: Fix off-by-one in prescale max
X-Git-Tag: v6.11-rc7~27^2~2
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=ff949d981c775332be94be70397ee1df20bc68e5;p=users%2Fhch%2Fmisc.git

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

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>
Link: https://patch.msgid.link/20240905111537.90389-1-wahrenst@gmx.net
Signed-off-by: Mark Brown <broonie@kernel.org>
---

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;