[U-Boot] [PATCH 22/32] Blackfin: bfin_spi: round up clock divider

Mike Frysinger vapier at gentoo.org
Sun Jan 17 15:39:13 CET 2010


From: Cliff Cai <cliff.cai at analog.com>

If the requested clock cannot be exactly obtained, round it up so that we
err on the side of slightly slower rather than slightly faster.

Signed-off-by: Cliff Cai <cliff.cai at analog.com>
Signed-off-by: Mike Frysinger <vapier at gentoo.org>
---
 drivers/spi/bfin_spi.c |    7 ++++++-
 1 files changed, 6 insertions(+), 1 deletions(-)

diff --git a/drivers/spi/bfin_spi.c b/drivers/spi/bfin_spi.c
index 093166e..f28d42b 100644
--- a/drivers/spi/bfin_spi.c
+++ b/drivers/spi/bfin_spi.c
@@ -85,6 +85,7 @@ struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
 		unsigned int max_hz, unsigned int mode)
 {
 	struct bfin_spi_slave *bss;
+	ulong sclk;
 	u32 mmr_base;
 	u32 baud;
 
@@ -105,7 +106,11 @@ struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
 		default: return NULL;
 	}
 
-	baud = get_sclk() / (2 * max_hz);
+	sclk = get_sclk();
+	baud = sclk / (2 * max_hz);
+	/* baud should be rounded up */
+	if (sclk % (2 * max_hz))
+		baud += 1;
 	if (baud < 2)
 		baud = 2;
 	else if (baud > (u16)-1)
-- 
1.6.6



More information about the U-Boot mailing list