linux-kernel - [PATCH 08/13] spi: spi-fsl-lpspi: Make prescale erratum a bool

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Message-Id: <20250814-james-nxp-lpspi-v1-8-9586d7815d14@linaro.org>
Date: Thu, 14 Aug 2025 17:06:48 +0100
From: James Clark <james.clark@...aro.org>
To: Frank Li <Frank.Li@....com>, Mark Brown <broonie@...nel.org>, 
 Clark Wang <xiaoning.wang@....com>, Fugang Duan <B38611@...escale.com>, 
 Gao Pan <pandy.gao@....com>, Fugang Duan <fugang.duan@....com>, 
 Rob Herring <robh@...nel.org>, Krzysztof Kozlowski <krzk+dt@...nel.org>, 
 Conor Dooley <conor+dt@...nel.org>, Shawn Guo <shawnguo@...nel.org>, 
 Sascha Hauer <s.hauer@...gutronix.de>, Fabio Estevam <festevam@...il.com>, 
 Larisa Grigore <larisa.grigore@....nxp.com>, 
 Larisa Grigore <larisa.grigore@....com>, 
 Ghennadi Procopciuc <ghennadi.procopciuc@....com>, 
 Ciprianmarian Costea <ciprianmarian.costea@....com>, s32@....com
Cc: James Clark <james.clark@...aro.org>, linux-spi@...r.kernel.org, 
 imx@...ts.linux.dev, linux-kernel@...r.kernel.org, 
 devicetree@...r.kernel.org
Subject: [PATCH 08/13] spi: spi-fsl-lpspi: Make prescale erratum a bool

This erratum only ever results in a max value of 1, otherwise the full 3
bits are available. To avoid repeating the same prescale values for
every new device's devdata, make it a bool.

Signed-off-by: James Clark <james.clark@...aro.org>
---
 drivers/spi/spi-fsl-lpspi.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/spi/spi-fsl-lpspi.c b/drivers/spi/spi-fsl-lpspi.c
index 332a852b746f..1013d5c994e9 100644
--- a/drivers/spi/spi-fsl-lpspi.c
+++ b/drivers/spi/spi-fsl-lpspi.c
@@ -96,7 +96,7 @@ static const char * const pincfgs[] = {
 };
 
 struct fsl_lpspi_devtype_data {
-	u8 prescale_max;
+	bool prescale_err : 1;
 };
 
 struct lpspi_config {
@@ -144,13 +144,16 @@ struct fsl_lpspi_data {
 /*
  * ERR051608 fixed or not:
  * https://www.nxp.com/docs/en/errata/i.MX93_1P87f.pdf
+ *
+ * Devices with ERR051608 have a max TCR_PRESCALE value of 1, otherwise the full
+ * 3 bits are available (0-7).
  */
 static const struct fsl_lpspi_devtype_data imx93_lpspi_devtype_data = {
-	.prescale_max = 1,
+	.prescale_err = true,
 };
 
 static const struct fsl_lpspi_devtype_data imx7ulp_lpspi_devtype_data = {
-	.prescale_max = 7,
+	.prescale_err = false,
 };
 
 static const struct of_device_id fsl_lpspi_dt_ids[] = {
@@ -329,12 +332,11 @@ static int fsl_lpspi_set_bitrate(struct fsl_lpspi_data *fsl_lpspi)
 {
 	struct lpspi_config config = fsl_lpspi->config;
 	unsigned int perclk_rate, div;
-	u8 prescale_max;
+	u8 prescale_max = fsl_lpspi->devtype_data->prescale_err ? 1 : 7;
 	u8 prescale;
 	int scldiv;
 
 	perclk_rate = clk_get_rate(fsl_lpspi->clk_per);
-	prescale_max = fsl_lpspi->devtype_data->prescale_max;
 
 	if (!config.speed_hz) {
 		dev_err(fsl_lpspi->dev,

-- 
2.34.1