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 this
driver */
+ { .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
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