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Subject[PATCH v3 01/12] spi: spi-fsl-dspi: Don't access reserved fields in SPI_MCR
Date
From: Vladimir Oltean <vladimir.oltean@nxp.com>

The SPI_MCR_PCSIS macro assumes that the controller has a number of chip
select signals equal to 6. That is not always the case, but actually is
described through the driver-specific "spi-num-chipselects" device tree
binding. LS1028A for example only has 4 chip selects.

Don't write to the upper bits of the PCSIS field, which are reserved in
the reference manual.

Fixes: 349ad66c0ab0 ("spi:Add Freescale DSPI driver for Vybrid VF610 platform")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
---
Changes in v4:
None.

Changes in v3:
None.

Changes in v2:
Remove duplicate phrase in commit message.

drivers/spi/spi-fsl-dspi.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c
index 50e3382f0c50..6ca35881881b 100644
--- a/drivers/spi/spi-fsl-dspi.c
+++ b/drivers/spi/spi-fsl-dspi.c
@@ -22,7 +22,7 @@

#define SPI_MCR 0x00
#define SPI_MCR_MASTER BIT(31)
-#define SPI_MCR_PCSIS (0x3F << 16)
+#define SPI_MCR_PCSIS(x) ((x) << 16)
#define SPI_MCR_CLR_TXF BIT(11)
#define SPI_MCR_CLR_RXF BIT(10)
#define SPI_MCR_XSPI BIT(3)
@@ -1200,7 +1200,10 @@ static const struct regmap_config dspi_xspi_regmap_config[] = {

static void dspi_init(struct fsl_dspi *dspi)
{
- unsigned int mcr = SPI_MCR_PCSIS;
+ unsigned int mcr;
+
+ /* Set idle states for all chip select signals to high */
+ mcr = SPI_MCR_PCSIS(GENMASK(dspi->ctlr->num_chipselect - 1, 0));

if (dspi->devtype_data->trans_mode == DSPI_XSPI_MODE)
mcr |= SPI_MCR_XSPI;
--
2.17.1
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