On 26/11/14 17:00, Sudeep Holla wrote:
Hi Viresh,
[...]
diff --git a/Documentation/devicetree/bindings/cpufreq/drivers.txt b/Documentation/devicetree/bindings/cpufreq/drivers.txt new file mode 100644 index 0000000..bd14917 --- /dev/null +++ b/Documentation/devicetree/bindings/cpufreq/drivers.txt @@ -0,0 +1,53 @@ +Binding to select which cpufreq driver to register
+It is a generic DT binding for selecting which cpufreq-driver to register for +any platform.
+The property listed below must be defined under node /cpus/cpu@0 node. We don't +support multiple CPUFreq driver currently for different cluster and so this +information isn't required to be present in CPUs of all clusters.
+Required properties: +- None
+Optional properties: +- dvfs-method: CPUFreq driver to probe. For example: "arm-bL-cpufreq-dt",
- "cpufreq-dt", etc
You should manage this with compatible rather than a new property as it's not a real hardware property. IMHO Rob's suggestion[1] should work fine.
IIUC, you can have the driver which create this platform device if DT has generic compatible unconditionally(e.g "cpufreq-dt" as you have chosen above). For all existing DT you can create a blacklist of compatibles to match(as it doesn't have the generic compatible) covering all the existing platforms using cpufreq-dt driver, there by you can even remove the platform device creating from multiple places. IMO something like the patch below should work(not tested, also late_initcall is used just to demonstrate the idea)
Rob, please correct me if my understanding is wrong.
Regards, Sudeep
[1] http://lists.infradead.org/pipermail/linux-arm-kernel/2014-May/256191.html
--->8
diff --git a/drivers/cpufreq/cpufreq-dt.c b/drivers/cpufreq/cpufreq-dt.c index f657c571b18e..19a616e298e0 100644 --- a/drivers/cpufreq/cpufreq-dt.c +++ b/drivers/cpufreq/cpufreq-dt.c @@ -387,6 +387,32 @@ static struct platform_driver dt_cpufreq_platdrv = { }; module_platform_driver(dt_cpufreq_platdrv);
+static const struct of_device_id compatible_machine_match[] = {
/* All new machines must have the below compatible to use thisdriver */
{ .compatible = "cpufreq-generic-dt" },/* BLACKLIST of existing users of cpufreq-dt below */{ .compatible = "samsung,exynos5420" },{ .compatible = "samsung,exynos5800" },
Please ignore the above 2 compatible values in this context, I just chose randomly 2 values but I now realize that there are big-little platforms and might not use this driver :(
Regards, Sudeep