mfd: AB8500 mask off irrelevant bits from the SPI message
The registers on the AB8500 are only 8 bits wide, so the content
of the remaining bits is undefined. Let's mask off the undefined
stuff when returning a register in an SPI read.
Acked-by: Rabin Vincent <rabin.vincent@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/drivers/mfd/ab8500-spi.c b/drivers/mfd/ab8500-spi.c
index b81d4f7..e1c8b62 100644
--- a/drivers/mfd/ab8500-spi.c
+++ b/drivers/mfd/ab8500-spi.c
@@ -68,7 +68,12 @@
ret = spi_sync(spi, &msg);
if (!ret)
- ret = ab8500->rx_buf[0];
+ /*
+ * Only the 8 lowermost bytes are
+ * defined with value, the rest may
+ * vary depending on chip/board noise.
+ */
+ ret = ab8500->rx_buf[0] & 0xFFU;
return ret;
}