| Message ID | 1360957573-864-2-git-send-email-dianders@chromium.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 16 February 2013 04:46, Doug Anderson <dianders@chromium.org> wrote: > We need to use the i2c-arbitrator to talk to any of the devices on i2c > bus 4 on exynos5250-snow so that we don't confuse the embedded > controller (EC). Add the i2c-arbitrator to the device tree. As we > add future devices (keyboard, sbs, tps65090) we'll add them on top of > this. > > The arbitrated bus is numbered 104 simply as a convenience to make it > easier for people poking around to guess that it might have something > to do with the physical bus 4. > > The addition is split between the cros5250-common and the snow device > tree file since not all cros5250-class devices use arbitration. > > Signed-off-by: Doug Anderson <dianders@chromium.org> Tested-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com> The patch set [v3] is tested on snow with test case which uses i2c-4 from both EC and AP side continuously for a more than a couple of minutes. > --- > Changes in v3: None > Changes in v2: > - Use new device tree property names / compatible string. > - Include that the GPIOs for arbitration are active low. > > arch/arm/boot/dts/cros5250-common.dtsi | 5 ++++- > arch/arm/boot/dts/exynos5250-snow.dts | 25 +++++++++++++++++++++++++ > 2 files changed, 29 insertions(+), 1 deletion(-) > > diff --git a/arch/arm/boot/dts/cros5250-common.dtsi b/arch/arm/boot/dts/cros5250-common.dtsi > index 46c0980..f451375 100644 > --- a/arch/arm/boot/dts/cros5250-common.dtsi > +++ b/arch/arm/boot/dts/cros5250-common.dtsi > @@ -58,7 +58,10 @@ > }; > > i2c@12CA0000 { > - status = "disabled"; > + samsung,i2c-sda-delay = <100>; > + samsung,i2c-max-bus-freq = <66000>; > + gpios = <&gpa2 0 3 3 0>, > + <&gpa2 1 3 3 0>; > }; > > i2c@12CB0000 { > diff --git a/arch/arm/boot/dts/exynos5250-snow.dts b/arch/arm/boot/dts/exynos5250-snow.dts > index 17dd951..d2d4b48 100644 > --- a/arch/arm/boot/dts/exynos5250-snow.dts > +++ b/arch/arm/boot/dts/exynos5250-snow.dts > @@ -16,6 +16,10 @@ > model = "Google Snow"; > compatible = "google,snow", "samsung,exynos5250"; > > + aliases { > + i2c104 = &i2c_104; > + }; > + > gpio-keys { > compatible = "gpio-keys"; > > @@ -29,6 +33,27 @@ > }; > }; > > + i2c-arbitrator { > + compatible = "i2c-arbitrator-cros-ec"; > + #address-cells = <1>; > + #size-cells = <0>; > + > + i2c-parent = <&{/i2c@12CA0000}>; > + > + ap-claim-gpio = <&gpf0 3 1 0x10000 0>; > + ec-claim-gpio = <&gpe0 4 0 0x10003 0>; > + slew-delay-us = <10>; > + wait-retry-us = <3000>; > + wait-free-us = <50000>; > + > + /* Use ID 104 as a hint that we're on physical bus 4 */ > + i2c_104: i2c@0 { > + reg = <0>; > + #address-cells = <1>; > + #size-cells = <0>; > + }; > + }; > + > /* > * On Snow we've got SIP WiFi and so can keep drive strengths low to > * reduce EMI. > -- > 1.8.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- Shine bright, (: Nav :)
Naveen Krishna Ch wrote: > On 16 February 2013 04:46, Doug Anderson <dianders@chromium.org> wrote: > > We need to use the i2c-arbitrator to talk to any of the devices on i2c > > bus 4 on exynos5250-snow so that we don't confuse the embedded > > controller (EC). Add the i2c-arbitrator to the device tree. As we > > add future devices (keyboard, sbs, tps65090) we'll add them on top of > > this. > > > > The arbitrated bus is numbered 104 simply as a convenience to make it > > easier for people poking around to guess that it might have something > > to do with the physical bus 4. > > > > The addition is split between the cros5250-common and the snow device > > tree file since not all cros5250-class devices use arbitration. > > > > Signed-off-by: Doug Anderson <dianders@chromium.org> > Tested-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com> > The patch set [v3] is tested on snow with test case which uses i2c-4 from both > EC and AP side continuously for a more than a couple of minutes. > Thanks for your test and looks good to me. BTW, Doug, I think, this should be re-worked to use pinctrl. Can you? Thanks. - Kukjin > > --- > > Changes in v3: None > > Changes in v2: > > - Use new device tree property names / compatible string. > > - Include that the GPIOs for arbitration are active low. > > > > arch/arm/boot/dts/cros5250-common.dtsi | 5 ++++- > > arch/arm/boot/dts/exynos5250-snow.dts | 25 +++++++++++++++++++++++++ > > 2 files changed, 29 insertions(+), 1 deletion(-) > > > > diff --git a/arch/arm/boot/dts/cros5250-common.dtsi > b/arch/arm/boot/dts/cros5250-common.dtsi > > index 46c0980..f451375 100644 > > --- a/arch/arm/boot/dts/cros5250-common.dtsi > > +++ b/arch/arm/boot/dts/cros5250-common.dtsi > > @@ -58,7 +58,10 @@ > > }; > > > > i2c@12CA0000 { > > - status = "disabled"; > > + samsung,i2c-sda-delay = <100>; > > + samsung,i2c-max-bus-freq = <66000>; > > + gpios = <&gpa2 0 3 3 0>, > > + <&gpa2 1 3 3 0>; > > }; > > > > i2c@12CB0000 { > > diff --git a/arch/arm/boot/dts/exynos5250-snow.dts > b/arch/arm/boot/dts/exynos5250-snow.dts > > index 17dd951..d2d4b48 100644 > > --- a/arch/arm/boot/dts/exynos5250-snow.dts > > +++ b/arch/arm/boot/dts/exynos5250-snow.dts > > @@ -16,6 +16,10 @@ > > model = "Google Snow"; > > compatible = "google,snow", "samsung,exynos5250"; > > > > + aliases { > > + i2c104 = &i2c_104; > > + }; > > + > > gpio-keys { > > compatible = "gpio-keys"; > > > > @@ -29,6 +33,27 @@ > > }; > > }; > > > > + i2c-arbitrator { > > + compatible = "i2c-arbitrator-cros-ec"; > > + #address-cells = <1>; > > + #size-cells = <0>; > > + > > + i2c-parent = <&{/i2c@12CA0000}>; > > + > > + ap-claim-gpio = <&gpf0 3 1 0x10000 0>; > > + ec-claim-gpio = <&gpe0 4 0 0x10003 0>; > > + slew-delay-us = <10>; > > + wait-retry-us = <3000>; > > + wait-free-us = <50000>; > > + > > + /* Use ID 104 as a hint that we're on physical bus 4 */ > > + i2c_104: i2c@0 { > > + reg = <0>; > > + #address-cells = <1>; > > + #size-cells = <0>; > > + }; > > + }; > > + > > /* > > * On Snow we've got SIP WiFi and so can keep drive strengths low to > > * reduce EMI. > > -- > > 1.8.1 > > > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > Please read the FAQ at http://www.tux.org/lkml/ > > > > -- > Shine bright, > (: Nav :)
Kukjin,
On Wed, Mar 13, 2013 at 12:30 AM, Kukjin Kim <kgene.kim@samsung.com> wrote:
> BTW, Doug, I think, this should be re-worked to use pinctrl. Can you?
Yes, I've already got this locally. I hadn't sent it up yet since I
wasn't sure whether pinctrl would land before or after this. I'll
send it up today against my local cherry-pick of Thomas's pinctrl
stuff (since it doesn't seem to be in linux-next nor in
arm-soc/for-next).
Naveen: I'm going to keep your Tested-by on all 3 patches if that's
OK. The only difference will be the gpio specifier in the device tree
and the change is trivial.
-Doug
diff --git a/arch/arm/boot/dts/cros5250-common.dtsi b/arch/arm/boot/dts/cros5250-common.dtsi index 46c0980..f451375 100644 --- a/arch/arm/boot/dts/cros5250-common.dtsi +++ b/arch/arm/boot/dts/cros5250-common.dtsi @@ -58,7 +58,10 @@ }; i2c@12CA0000 { - status = "disabled"; + samsung,i2c-sda-delay = <100>; + samsung,i2c-max-bus-freq = <66000>; + gpios = <&gpa2 0 3 3 0>, + <&gpa2 1 3 3 0>; }; i2c@12CB0000 { diff --git a/arch/arm/boot/dts/exynos5250-snow.dts b/arch/arm/boot/dts/exynos5250-snow.dts index 17dd951..d2d4b48 100644 --- a/arch/arm/boot/dts/exynos5250-snow.dts +++ b/arch/arm/boot/dts/exynos5250-snow.dts @@ -16,6 +16,10 @@ model = "Google Snow"; compatible = "google,snow", "samsung,exynos5250"; + aliases { + i2c104 = &i2c_104; + }; + gpio-keys { compatible = "gpio-keys"; @@ -29,6 +33,27 @@ }; }; + i2c-arbitrator { + compatible = "i2c-arbitrator-cros-ec"; + #address-cells = <1>; + #size-cells = <0>; + + i2c-parent = <&{/i2c@12CA0000}>; + + ap-claim-gpio = <&gpf0 3 1 0x10000 0>; + ec-claim-gpio = <&gpe0 4 0 0x10003 0>; + slew-delay-us = <10>; + wait-retry-us = <3000>; + wait-free-us = <50000>; + + /* Use ID 104 as a hint that we're on physical bus 4 */ + i2c_104: i2c@0 { + reg = <0>; + #address-cells = <1>; + #size-cells = <0>; + }; + }; + /* * On Snow we've got SIP WiFi and so can keep drive strengths low to * reduce EMI.
We need to use the i2c-arbitrator to talk to any of the devices on i2c bus 4 on exynos5250-snow so that we don't confuse the embedded controller (EC). Add the i2c-arbitrator to the device tree. As we add future devices (keyboard, sbs, tps65090) we'll add them on top of this. The arbitrated bus is numbered 104 simply as a convenience to make it easier for people poking around to guess that it might have something to do with the physical bus 4. The addition is split between the cros5250-common and the snow device tree file since not all cros5250-class devices use arbitration. Signed-off-by: Doug Anderson <dianders@chromium.org> --- Changes in v3: None Changes in v2: - Use new device tree property names / compatible string. - Include that the GPIOs for arbitration are active low. arch/arm/boot/dts/cros5250-common.dtsi | 5 ++++- arch/arm/boot/dts/exynos5250-snow.dts | 25 +++++++++++++++++++++++++ 2 files changed, 29 insertions(+), 1 deletion(-)