[PATCH 2/2] spi/fsl-espi: Make sure pm is within 2..32

[Sebastian Andrzej Siewior <bigeasy-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org>]

The reference manual says that pm has to stay within 2 and 32. So the
lowest frequency is 32 and DIV16 set, the highest is 2 and DIV16 unset.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org>
---
 drivers/spi/spi-fsl-espi.c |   10 ++++++----
 1 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/spi/spi-fsl-espi.c b/drivers/spi/spi-fsl-espi.c
index 43350f9..7523a24 100644
--- a/drivers/spi/spi-fsl-espi.c
+++ b/drivers/spi/spi-fsl-espi.c
@@ -182,16 +182,18 @@ static int fsl_espi_setup_transfer(struct spi_device *spi,
 		cs->hw_mode |= CSMODE_DIV16;
 		pm = DIV_ROUND_UP(mpc8xxx_spi->spibrg, hz * 16 * 4);
 
-		WARN_ONCE(pm > 16, "%s: Requested speed is too low: %d Hz. "
+		WARN_ONCE(pm > 33, "%s: Requested speed is too low: %d Hz. "
 			  "Will use %d Hz instead.\n", dev_name(&spi->dev),
-			  hz, mpc8xxx_spi->spibrg / 1024);
-		if (pm > 16)
-			pm = 16;
+				hz, mpc8xxx_spi->spibrg / (4 * 16 * (32 + 1)));
+		if (pm > 33)
+			pm = 33;
 	} else {
 		pm = DIV_ROUND_UP(mpc8xxx_spi->spibrg, hz * 4);
 	}
 	if (pm)
 		pm--;
+	if (pm < 2)
+		pm = 2;
 
 	cs->hw_mode |= CSMODE_PM(pm);
 
-- 
1.7.9.1


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