On Wednesday 03 July 2013, Christian Ruppert wrote: > On Wed, Jul 03, 2013 at 01:43:11PM +0200, Arnd Bergmann wrote: > > On Wednesday 26 June 2013, Wolfram Sang wrote: > > > On Wed, Jun 26, 2013 at 10:55:06AM +0200, Christian Ruppert wrote: > > > > This patch makes the SDA hold time configurable through device tree. > > > > > > > > Signed-off-by: Christian Ruppert <christian.ruppert@xxxxxxxxxx> > > > > Signed-off-by: Pierrick Hascoet <pierrick.hascoet@xxxxxxxxxx> > > > > > > Applied to for-next, thanks for keeping at it and providing lots of > > > useful information. Much appreciated! > > > > Sorry, but I got a regression that I didn't find reported elsewhere > > so far, even though it breaks a lot of the ARM defconfig builds: > > > > drivers/built-in.o: In function `dw_i2c_probe': > > /git/arm-soc/drivers/i2c/busses/i2c-designware-platdrv.c:125: undefined reference to `__udivdi3' > > > > I suspect you want something like the change below. > > This looks similar to a patch Vincent Stehle submitted yesterday, see > https://lkml.org/lkml/2013/7/2/145 Thanks for the link. Actually his patch looks wrong to me, because dev->sda_hold_time = div_u64((u64)ic_clk * ht + 500000, 1000000); assigns the division remainder to sda_hold_time, not the quotient. Arnd > > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> > > > > diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c > > index def79b5..57e3a07 100644 > > --- a/drivers/i2c/busses/i2c-designware-platdrv.c > > +++ b/drivers/i2c/busses/i2c-designware-platdrv.c > > @@ -119,10 +119,13 @@ static int dw_i2c_probe(struct platform_device *pdev) > > if (pdev->dev.of_node) { > > u32 ht = 0; > > u32 ic_clk = dev->get_clk_rate_khz(dev); > > + u64 hold_time; > > > > of_property_read_u32(pdev->dev.of_node, > > "i2c-sda-hold-time-ns", &ht); > > - dev->sda_hold_time = ((u64)ic_clk * ht + 500000) / 1000000; > > + hold_time = (u64)ic_clk * ht + 500000; > > + do_div(hold_time, 1000000); > > + dev->sda_hold_time = hold_time; > > } > > > > dev->functionality = -- 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
