| Message ID | 1405500606-5752-2-git-send-email-drake@endlessm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 16.07.2014 10:50, Daniel Drake wrote: > Increase max i2c bus frequency beyond the default for faster > data transfers. According to the manual, these faster speeds are > only available when the board is wired up the right way. In this case, > the vendor kernel has run at this speed for a long time. > > sda-delay is needed for talking to RTC on PMIC, otherwise the i2c > controller never sees an ACK. Strangely the other PMIC i2c slave (the > main one) works fine even without this delay. I Chose value 100 to > match the vendor kernel. > > Signed-off-by: Daniel Drake <drake@endlessm.com> > --- > arch/arm/boot/dts/exynos4412-odroid-common.dtsi | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/arch/arm/boot/dts/exynos4412-odroid-common.dtsi b/arch/arm/boot/dts/exynos4412-odroid-common.dtsi > index cb6f55f..adadaf9 100644 > --- a/arch/arm/boot/dts/exynos4412-odroid-common.dtsi > +++ b/arch/arm/boot/dts/exynos4412-odroid-common.dtsi > @@ -134,6 +134,8 @@ > i2c@13860000 { > pinctrl-0 = <&i2c0_bus>; > pinctrl-names = "default"; > + samsung,i2c-sda-delay = <100>; > + samsung,i2c-max-bus-freq = <400000>; > status = "okay"; > > usb3503: usb3503@08 { > Reviewed-by: Tomasz Figa <t.figa@samsung.com> -- Best regards, Tomasz
Tested on an Odroid-U2: Tested-by: Tomeu Vizoso <tomeu.vizoso@collabora.com> Thanks, Tomeu On 16 July 2014 10:50, Daniel Drake <drake@endlessm.com> wrote: > Increase max i2c bus frequency beyond the default for faster > data transfers. According to the manual, these faster speeds are > only available when the board is wired up the right way. In this case, > the vendor kernel has run at this speed for a long time. > > sda-delay is needed for talking to RTC on PMIC, otherwise the i2c > controller never sees an ACK. Strangely the other PMIC i2c slave (the > main one) works fine even without this delay. I Chose value 100 to > match the vendor kernel. > > Signed-off-by: Daniel Drake <drake@endlessm.com> > --- > arch/arm/boot/dts/exynos4412-odroid-common.dtsi | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/arch/arm/boot/dts/exynos4412-odroid-common.dtsi b/arch/arm/boot/dts/exynos4412-odroid-common.dtsi > index cb6f55f..adadaf9 100644 > --- a/arch/arm/boot/dts/exynos4412-odroid-common.dtsi > +++ b/arch/arm/boot/dts/exynos4412-odroid-common.dtsi > @@ -134,6 +134,8 @@ > i2c@13860000 { > pinctrl-0 = <&i2c0_bus>; > pinctrl-names = "default"; > + samsung,i2c-sda-delay = <100>; > + samsung,i2c-max-bus-freq = <400000>; > status = "okay"; > > usb3503: usb3503@08 { > -- > 1.9.1 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
diff --git a/arch/arm/boot/dts/exynos4412-odroid-common.dtsi b/arch/arm/boot/dts/exynos4412-odroid-common.dtsi index cb6f55f..adadaf9 100644 --- a/arch/arm/boot/dts/exynos4412-odroid-common.dtsi +++ b/arch/arm/boot/dts/exynos4412-odroid-common.dtsi @@ -134,6 +134,8 @@ i2c@13860000 { pinctrl-0 = <&i2c0_bus>; pinctrl-names = "default"; + samsung,i2c-sda-delay = <100>; + samsung,i2c-max-bus-freq = <400000>; status = "okay"; usb3503: usb3503@08 {
Increase max i2c bus frequency beyond the default for faster data transfers. According to the manual, these faster speeds are only available when the board is wired up the right way. In this case, the vendor kernel has run at this speed for a long time. sda-delay is needed for talking to RTC on PMIC, otherwise the i2c controller never sees an ACK. Strangely the other PMIC i2c slave (the main one) works fine even without this delay. I Chose value 100 to match the vendor kernel. Signed-off-by: Daniel Drake <drake@endlessm.com> --- arch/arm/boot/dts/exynos4412-odroid-common.dtsi | 2 ++ 1 file changed, 2 insertions(+)