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| author | Michael Hennerich <michael.hennerich@analog.com> | 2009-05-18 08:14:41 -0400 |
|---|---|---|
| committer | Ben Dooks <ben-linux@fluff.org> | 2009-06-13 10:39:25 +0100 |
| commit | 9528d1c7a541b481a0e80301dc8d545848104023 (patch) | |
| tree | d42eedf34ee8d79d4fe4acf3a48c260748443b34 /drivers/i2c | |
| parent | f3ad116588151b3371ae4e092290e4f48e62b8bb (diff) | |
| download | linux-3.10-9528d1c7a541b481a0e80301dc8d545848104023.tar.gz linux-3.10-9528d1c7a541b481a0e80301dc8d545848104023.tar.bz2 linux-3.10-9528d1c7a541b481a0e80301dc8d545848104023.zip | |
i2c: Blackfin TWI: make sure we don't end up with a CLKDIV=0
Make sure we don't end up with an invalid CLKDIV=0 in case someone
specifies 20kHz SCL or less (5 * 1024 / 20 = 0x100).
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
[ben-linux@fluff.org: shortened subject line]
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/busses/Kconfig | 2 | ||||
| -rw-r--r-- | drivers/i2c/busses/i2c-bfin-twi.c | 11 |
2 files changed, 9 insertions, 4 deletions
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index f1c6ca7e285..c8460fa9cfa 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -298,7 +298,7 @@ config I2C_BLACKFIN_TWI config I2C_BLACKFIN_TWI_CLK_KHZ int "Blackfin TWI I2C clock (kHz)" depends on I2C_BLACKFIN_TWI - range 10 400 + range 21 400 default 50 help The unit of the TWI clock is kHz. diff --git a/drivers/i2c/busses/i2c-bfin-twi.c b/drivers/i2c/busses/i2c-bfin-twi.c index fc548b3d002..77cafb6ba92 100644 --- a/drivers/i2c/busses/i2c-bfin-twi.c +++ b/drivers/i2c/busses/i2c-bfin-twi.c @@ -614,6 +614,7 @@ static int i2c_bfin_twi_probe(struct platform_device *pdev) struct i2c_adapter *p_adap; struct resource *res; int rc; + unsigned int clkhilow; iface = kzalloc(sizeof(struct bfin_twi_iface), GFP_KERNEL); if (!iface) { @@ -675,10 +676,14 @@ 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); + /* + * 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) + */ + clkhilow = 5 * 1024 / CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ; + /* Set Twi interface clock as specified */ - write_CLKDIV(iface, ((5*1024 / CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ) - << 8) | ((5*1024 / CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ) - & 0xFF)); + write_CLKDIV(iface, (clkhilow << 8) | clkhilow); /* Enable TWI */ write_CONTROL(iface, read_CONTROL(iface) | TWI_ENA); |