On Tue, Aug 23, 2016 at 05:29:16PM +0800, Finley Xiao wrote: > > > 在 2016/8/23 17:03, Heiko Stübner 写道: > >Hi Finley, > > > >Am Dienstag, 23. August 2016, 12:10:27 schrieb Finley Xiao: > >>在 2016/8/19 21:36, Rob Herring 写道: > >>>On Tue, Aug 16, 2016 at 10:38:59AM +0800, Finlye Xiao wrote: > >>>>From: Finley Xiao <finley.xiao@xxxxxxxxxxxxxx> > >>>> > >>>>This patch supports adjusting opp's voltage according to leakage > >>>> > >>>>Signed-off-by: Finley Xiao <finley.xiao@xxxxxxxxxxxxxx> > >>>>--- > >>>> > >>>> .../devicetree/bindings/power/rockchip-cpu-avs.txt | 37 +++ > >>>> drivers/power/avs/Kconfig | 8 + > >>>> drivers/power/avs/Makefile | 1 + > >>>> drivers/power/avs/rockchip-cpu-avs.c | 314 > >>>> +++++++++++++++++++++ 4 files changed, 360 insertions(+) > >>>> create mode 100644 > >>>> Documentation/devicetree/bindings/power/rockchip-cpu-avs.txt create > >>>> mode 100644 drivers/power/avs/rockchip-cpu-avs.c > >>>> > >>>>diff --git a/Documentation/devicetree/bindings/power/rockchip-cpu-avs.txt > >>>>b/Documentation/devicetree/bindings/power/rockchip-cpu-avs.txt new file > >>>>mode 100644 > >>>>index 0000000..90f6b08 > >>>>--- /dev/null > >>>>+++ b/Documentation/devicetree/bindings/power/rockchip-cpu-avs.txt > >>>>@@ -0,0 +1,37 @@ > >>>>+Rockchip cpu avs device tree bindings > >>>>+------------------------------------- > >>>>+ > >>>>+Under the same frequency, the operating voltage tends to decrease with > >>>>+increasing leakage. so it is necessary to adjust opp's voltage according > >>>>+to leakage for power. > >>>>+ > >>>>+ > >>>>+Required properties: > >>>>+- compatible: Should be one of the following. > >>>>+ - "rockchip,rk3399-cpu-avs" - for RK3399 SoCs. > >>>>+- leakage-volt-<name>: Named leakage-volt property. At runtime, the > >>>>+ platform can find a cpu's cluster_id according to it's cpu_id and > >>>>match > >>>>+ leakage-volt-<name> property. The property is an array of 3-tuples > >>>>+ items, and each item consists of leakage and voltage like > >>>>+ <min-leakage-mA max-leakage-mA vol-uV>. > >>>>+ min-leakage: minimum leakage in mA. > >>>>+ max-leakage: maximum leakage in mA. > >>>>+ vol: voltage in microvolt. > >>>How do you determine these values? When do they vary? > >>How do you determine these values? > >> > >>run antutu-benchmark > >>leakage freq min_volt > >>30mA 1608MHz 1025mV > >>40mA 1608MHz 1000mV > >>50mA 1608MHz 975mV > >> > >> From the table, we see the min_volt decrease with increasing leakage. > >>So we can set the default opp-microvolt 1025mV for 1608MHz, > >>and add an leakage_volt_cluster0 property as follows. > >>leakage_volt_cluster0 = < > >> /* min(mA) max(mA) volt(uV)*/ > >> 0 40 0 > >> 41 50 (-25000) > >> 51 254 (-50000) > >> > >>>; > >>If the leakage is between 41mA and 50mA，the opp-microvolt will subtract > >>25mV。 If the leakage is between 41mA and 50mA，the opp-microvolt will > >>subtract 50mV。 > >> > >>When do they vary? > >> > >> From the code, > >>cpufreq_online > >>--cpufreq_driver->init(policy); /* add new opp table */ > >>--blocking_notifier_call_chain(&cpufreq_policy_notifier_list, > >>CPUFREQ_START, policy); > >>--cpufreq_init_policy > >>----cpufreq_set_policy > >>--------__cpufreq_governor(policy, CPUFREQ_GOV_START); > >> > >>The cpu's opp table is added in the init function(cpufreq_init)，and I will > >>register a cpufreq notifier, once the first cpu of cluster is onlined, > >>my notifer will be called, and if the event is CPUFREQ_START，it will modify > >>the opp-microvolt according to leakage_volt_cluster0. > >I think what Rob was asking with "when do they vary" is, are these leakage > >values the same for each and every rk3399 soc or are they determined > >separately for each board-type using the rk3399. > > Oh, sorry, I misunderstood. > They are the same for every rk3399 soc. Then I think the values should go in the kernel at least until we define a common way to handle this. Rob -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
