summaryrefslogtreecommitdiff
path: root/drivers/spi/davinci_spi.c
diff options
context:
space:
mode:
authorMark Brown <broonie@opensource.wolfsonmicro.com>2010-05-31 14:07:15 +0400
committerMark Brown <broonie@opensource.wolfsonmicro.com>2010-05-31 14:07:15 +0400
commite37c83c06c2690157a989df40dc99a6b61c9ea15 (patch)
tree024dfb8b2c9abeec9ca7cb0c0136c276d9aacc91 /drivers/spi/davinci_spi.c
parentce1f7d30766f6549db6fa0b9e595e0d26a5b7d9a (diff)
parent67a3e12b05e055c0415c556a315a3d3eb637e29e (diff)
downloadlinux-e37c83c06c2690157a989df40dc99a6b61c9ea15.tar.xz
Merge commit 'v2.6.35-rc1' into for-2.6.36
Diffstat (limited to 'drivers/spi/davinci_spi.c')
-rw-r--r--drivers/spi/davinci_spi.c13
1 files changed, 10 insertions, 3 deletions
diff --git a/drivers/spi/davinci_spi.c b/drivers/spi/davinci_spi.c
index 225ab60b02c4..b85090caf7cf 100644
--- a/drivers/spi/davinci_spi.c
+++ b/drivers/spi/davinci_spi.c
@@ -27,6 +27,7 @@
#include <linux/dma-mapping.h>
#include <linux/spi/spi.h>
#include <linux/spi/spi_bitbang.h>
+#include <linux/slab.h>
#include <mach/spi.h>
#include <mach/edma.h>
@@ -300,7 +301,7 @@ static int davinci_spi_setup_transfer(struct spi_device *spi,
struct davinci_spi *davinci_spi;
struct davinci_spi_platform_data *pdata;
u8 bits_per_word = 0;
- u32 hz = 0, prescale;
+ u32 hz = 0, prescale = 0, clkspeed;
davinci_spi = spi_master_get_devdata(spi->master);
pdata = davinci_spi->pdata;
@@ -337,10 +338,16 @@ static int davinci_spi_setup_transfer(struct spi_device *spi,
set_fmt_bits(davinci_spi->base, bits_per_word & 0x1f,
spi->chip_select);
- prescale = ((clk_get_rate(davinci_spi->clk) / hz) - 1) & 0xff;
+ clkspeed = clk_get_rate(davinci_spi->clk);
+ if (hz > clkspeed / 2)
+ prescale = 1 << 8;
+ if (hz < clkspeed / 256)
+ prescale = 255 << 8;
+ if (!prescale)
+ prescale = ((clkspeed / hz - 1) << 8) & 0x0000ff00;
clear_fmt_bits(davinci_spi->base, 0x0000ff00, spi->chip_select);
- set_fmt_bits(davinci_spi->base, prescale << 8, spi->chip_select);
+ set_fmt_bits(davinci_spi->base, prescale, spi->chip_select);
return 0;
}