| Message ID | 1430417266-14900-1-git-send-email-linux_wi@tinag.ch |
|---|---|
| State | Superseded |
| Headers | show |
On Thu, Apr 30, 2015 at 11:37 PM, Silvan Wicki <linux_wi@tinag.ch> wrote: > Prevents that cdiv can be an uneven number as per datasheet cdiv is > always rounded down to an even number. > > Datasheet at page 34 on > http://www.raspberrypi.org/wp-content/uploads/2012/02/BCM2835-ARM-Peripherals.pdf > > Signed-off-by: Silvan Wicki <linux_wi@tinag.ch> > --- > drivers/i2c/busses/i2c-bcm2708.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-bcm2708.c b/drivers/i2c/busses/i2c-bcm2708.c > index 81e9374..454ab48 100644 > --- a/drivers/i2c/busses/i2c-bcm2708.c > +++ b/drivers/i2c/busses/i2c-bcm2708.c > @@ -441,9 +441,15 @@ static int bcm2708_i2c_probe(struct platform_device *pdev) > > bus_hz = clk_get_rate(bi->clk); > cdiv = bus_hz / baudrate; > - if (cdiv > 0xffff) { > - cdiv = 0xffff; > + /* as per datasheet cdiv is always rounded down to an even number */ > + if (cdiv > 0xfffe) { > + cdiv = 0xfffe; Use #define ~Rajeev > baudrate = bus_hz / cdiv; > + } else { > + if ((cdiv & 0xfffe) != cdiv) { > + cdiv &= 0xfffe; > + baudrate = bus_hz / cdiv; > + } > } > bi->cdiv = cdiv; > > -- > 2.1.4 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-i2c" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/i2c/busses/i2c-bcm2708.c b/drivers/i2c/busses/i2c-bcm2708.c index 81e9374..454ab48 100644 --- a/drivers/i2c/busses/i2c-bcm2708.c +++ b/drivers/i2c/busses/i2c-bcm2708.c @@ -441,9 +441,15 @@ static int bcm2708_i2c_probe(struct platform_device *pdev) bus_hz = clk_get_rate(bi->clk); cdiv = bus_hz / baudrate; - if (cdiv > 0xffff) { - cdiv = 0xffff; + /* as per datasheet cdiv is always rounded down to an even number */ + if (cdiv > 0xfffe) { + cdiv = 0xfffe; baudrate = bus_hz / cdiv; + } else { + if ((cdiv & 0xfffe) != cdiv) { + cdiv &= 0xfffe; + baudrate = bus_hz / cdiv; + } } bi->cdiv = cdiv;
Prevents that cdiv can be an uneven number as per datasheet cdiv is always rounded down to an even number. Datasheet at page 34 on http://www.raspberrypi.org/wp-content/uploads/2012/02/BCM2835-ARM-Peripherals.pdf Signed-off-by: Silvan Wicki <linux_wi@tinag.ch> --- drivers/i2c/busses/i2c-bcm2708.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)