From 87bf5ab82884c829366914aaa813cc8b07b9fe58 Mon Sep 17 00:00:00 2001
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Thu, 15 Mar 2012 18:42:32 +0100
Subject: [PATCH] spi/fsl-espi: Make sure pm is within 2..32
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@linutronix.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
---
drivers/spi/spi-fsl-espi.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/drivers/spi/spi-fsl-espi.c b/drivers/spi/spi-fsl-espi.c
index 43350f999314..7523a2429d09 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);
--
2.34.1