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authorSonic Zhang <sonic.zhang@analog.com>2009-12-21 09:28:30 -0500
committerBen Dooks <ben-linux@fluff.org>2009-12-24 01:24:48 +0000
commitac07fb4dc1908d300f50fa711982c9d750eb59f7 (patch)
tree9a3e6149726b63a74d141bb4fe86b7fb3399435f
parentc9f937e4a3f4ebf9924ec21d80632e5eb61d949c (diff)
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i2c-bfin-twi: fix CLKDIV calculation
Calculation of the CLKDIV speed setting should be done using base 10 math rather than base 2. We also avoid exceeding the spec due to integer truncation and a 50% duty cycle. Signed-off-by: Sonic Zhang <sonic.zhang@analog.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Ben Dooks <ben-linux@fluff.org>
-rw-r--r--drivers/i2c/busses/i2c-bfin-twi.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/i2c/busses/i2c-bfin-twi.c b/drivers/i2c/busses/i2c-bfin-twi.c
index b309ac2c3d5..fe3fb567317 100644
--- a/drivers/i2c/busses/i2c-bfin-twi.c
+++ b/drivers/i2c/busses/i2c-bfin-twi.c
@@ -693,13 +693,13 @@ static int i2c_bfin_twi_probe(struct platform_device *pdev)
}
/* Set TWI internal clock as 10MHz */
- write_CONTROL(iface, ((get_sclk() / 1024 / 1024 + 5) / 10) & 0x7F);
+ write_CONTROL(iface, ((get_sclk() / 1000 / 1000 + 5) / 10) & 0x7F);
/*
* We will not end up with a CLKDIV=0 because no one will specify
- * 20kHz SCL or less in Kconfig now. (5 * 1024 / 20 = 0x100)
+ * 20kHz SCL or less in Kconfig now. (5 * 1000 / 20 = 250)
*/
- clkhilow = 5 * 1024 / CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ;
+ clkhilow = ((10 * 1000 / CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ) + 1) / 2;
/* Set Twi interface clock as specified */
write_CLKDIV(iface, (clkhilow << 8) | clkhilow);