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authorSimon Horman <horms@verge.net.au>2012-03-28 18:01:09 +0900
committerChris Ball <cjb@laptop.org>2012-04-05 20:32:23 -0400
commitf93882570496aa02ba8a47bfaf81cce43046b978 (patch)
treee1493468f480ff958edc5e3013b513b4baa43641
parent5865f2876baa5c68fd0d50029dd220ce19f3d2af (diff)
mmc: sh_mmcif: double clock speed
Correct an off-by one error when calculating the clock divisor in cases where the host clock is a power of two of the target clock. Previously the divisor was one greater than the correct value in these cases leading to the clock being set at half the desired speed. Thanks to Guennadi Liakhovetski for working with me on the logic for this change. Tested-by: Cao Minh Hiep <hiepcm@gmail.com> Acked-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de> Signed-off-by: Simon Horman <horms@verge.net.au> Signed-off-by: Chris Ball <cjb@laptop.org>
-rw-r--r--drivers/mmc/host/sh_mmcif.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/mmc/host/sh_mmcif.c b/drivers/mmc/host/sh_mmcif.c
index aafaf0b6eb1..d79c6430c16 100644
--- a/drivers/mmc/host/sh_mmcif.c
+++ b/drivers/mmc/host/sh_mmcif.c
@@ -454,7 +454,8 @@ static void sh_mmcif_clock_control(struct sh_mmcif_host *host, unsigned int clk)
sh_mmcif_bitset(host, MMCIF_CE_CLK_CTRL, CLK_SUP_PCLK);
else
sh_mmcif_bitset(host, MMCIF_CE_CLK_CTRL, CLK_CLEAR &
- ((fls(host->clk / clk) - 1) << 16));
+ ((fls(DIV_ROUND_UP(host->clk,
+ clk) - 1) - 1) << 16));
sh_mmcif_bitset(host, MMCIF_CE_CLK_CTRL, CLK_ENABLE);
}