* [PATCH] ARM: dts: Switch i2c0 to 400kHz on rk3288-evb-rk808
@ 2014-09-11 4:30 Doug Anderson
2014-09-11 9:17 ` Addy
2014-09-11 9:23 ` Heiko Stübner
0 siblings, 2 replies; 3+ messages in thread
From: Doug Anderson @ 2014-09-11 4:30 UTC (permalink / raw)
To: linux-arm-kernel
We should be able to talk to the PMIC at 400kHz. No need to talk at
the slow 100kHz.
As measured by ftrace (with a bunch of extra patches, since cpufreq
for rk808 hasn't landed yet):
before this change: cpu0_set_target() => ~500us
after this change: cpu0_set_target() => ~300us
Signed-off-by: Doug Anderson <dianders@chromium.org>
---
arch/arm/boot/dts/rk3288-evb-rk808.dts | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/arm/boot/dts/rk3288-evb-rk808.dts b/arch/arm/boot/dts/rk3288-evb-rk808.dts
index 36db177..ff522f8 100644
--- a/arch/arm/boot/dts/rk3288-evb-rk808.dts
+++ b/arch/arm/boot/dts/rk3288-evb-rk808.dts
@@ -18,6 +18,7 @@
};
&i2c0 {
+ clock-frequency = <400000>;
status = "okay";
rk808: pmic at 1b {
--
2.1.0.rc2.206.gedb03e5
^ permalink raw reply related [flat|nested] 3+ messages in thread* [PATCH] ARM: dts: Switch i2c0 to 400kHz on rk3288-evb-rk808
2014-09-11 4:30 [PATCH] ARM: dts: Switch i2c0 to 400kHz on rk3288-evb-rk808 Doug Anderson
@ 2014-09-11 9:17 ` Addy
2014-09-11 9:23 ` Heiko Stübner
1 sibling, 0 replies; 3+ messages in thread
From: Addy @ 2014-09-11 9:17 UTC (permalink / raw)
To: linux-arm-kernel
On 11 Sep 2014 12:30, Doug Anderson writes:
> We should be able to talk to the PMIC at 400kHz. No need to talk at
> the slow 100kHz.
>
> As measured by ftrace (with a bunch of extra patches, since cpufreq
> for rk808 hasn't landed yet):
> before this change: cpu0_set_target() => ~500us
> after this change: cpu0_set_target() => ~300us
>
> Signed-off-by: Doug Anderson <dianders@chromium.org>
> ---
> arch/arm/boot/dts/rk3288-evb-rk808.dts | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/arch/arm/boot/dts/rk3288-evb-rk808.dts b/arch/arm/boot/dts/rk3288-evb-rk808.dts
> index 36db177..ff522f8 100644
> --- a/arch/arm/boot/dts/rk3288-evb-rk808.dts
> +++ b/arch/arm/boot/dts/rk3288-evb-rk808.dts
> @@ -18,6 +18,7 @@
> };
>
> &i2c0 {
> + clock-frequency = <400000>;
> status = "okay";
>
> rk808: pmic at 1b {
I have tested on rk3288-pinky board, it work well. so
Reviewed-by Addy Ke <addy.ke@rock-chips.com>
Tested-by Addy Ke <addy.ke@rock-chips.com>
^ permalink raw reply [flat|nested] 3+ messages in thread* [PATCH] ARM: dts: Switch i2c0 to 400kHz on rk3288-evb-rk808
2014-09-11 4:30 [PATCH] ARM: dts: Switch i2c0 to 400kHz on rk3288-evb-rk808 Doug Anderson
2014-09-11 9:17 ` Addy
@ 2014-09-11 9:23 ` Heiko Stübner
1 sibling, 0 replies; 3+ messages in thread
From: Heiko Stübner @ 2014-09-11 9:23 UTC (permalink / raw)
To: linux-arm-kernel
Am Mittwoch, 10. September 2014, 21:30:15 schrieb Doug Anderson:
> We should be able to talk to the PMIC at 400kHz. No need to talk at
> the slow 100kHz.
>
> As measured by ftrace (with a bunch of extra patches, since cpufreq
> for rk808 hasn't landed yet):
> before this change: cpu0_set_target() => ~500us
> after this change: cpu0_set_target() => ~300us
>
> Signed-off-by: Doug Anderson <dianders@chromium.org>
looks harmless :-)
I've added it to my v3.18-next/dts branch with Addy's tags
> ---
> arch/arm/boot/dts/rk3288-evb-rk808.dts | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/arch/arm/boot/dts/rk3288-evb-rk808.dts
> b/arch/arm/boot/dts/rk3288-evb-rk808.dts index 36db177..ff522f8 100644
> --- a/arch/arm/boot/dts/rk3288-evb-rk808.dts
> +++ b/arch/arm/boot/dts/rk3288-evb-rk808.dts
> @@ -18,6 +18,7 @@
> };
>
> &i2c0 {
> + clock-frequency = <400000>;
> status = "okay";
>
> rk808: pmic at 1b {
^ permalink raw reply [flat|nested] 3+ messages in thread
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2014-09-11 4:30 [PATCH] ARM: dts: Switch i2c0 to 400kHz on rk3288-evb-rk808 Doug Anderson
2014-09-11 9:17 ` Addy
2014-09-11 9:23 ` Heiko Stübner
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