On Sat, May 2, 2015 at 3:13 AM, Silvan Wicki <linux_wi@xxxxxxxx> 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@xxxxxxxx> > --- Reviewed-by: Rajeev Kumar <rajeevkumar.linux@xxxxxxxxx> > drivers/i2c/busses/i2c-bcm2708.c | 13 +++++++++++-- > 1 file changed, 11 insertions(+), 2 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-bcm2708.c b/drivers/i2c/busses/i2c-bcm2708.c > index 81e9374..dd7094a 100644 > --- a/drivers/i2c/busses/i2c-bcm2708.c > +++ b/drivers/i2c/busses/i2c-bcm2708.c > @@ -67,6 +67,9 @@ > #define BSC_S_DONE 0x00000002 > #define BSC_S_TA 0x00000001 > > +#define BSC_CDIV_MAX 0xFFFE > +#define BSC_CDIV_BITMASK 0xEFFF > + > #define I2C_TIMEOUT_MS 150 > #define I2C_WAIT_LOOP_COUNT 40 > > @@ -441,9 +444,15 @@ 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 > BSC_CDIV_MAX) { > + cdiv = BSC_CDIV_MAX; > baudrate = bus_hz / cdiv; > + } else { > + if ((cdiv & BSC_CDIV_BITMASK) != cdiv) { > + cdiv &= BSC_CDIV_BITMASK; > + 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@xxxxxxxxxxxxxxx > 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@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
