[PATCH 2/2] cpufreq: new function to query driver for flags

From: Mike Turquette
Date: Wed Oct 08 2014 - 03:49:45 EST


There are cases for CPUfreq driver flags to be exposed outside of the
CPUfreq core code. In particular the CPUFREQ_NO_SLEEP flag can be used
by CPUfreq governors to optimize when and how they call that drivers
.target callback. In fact this knowledge is a requirement for the
on-going work to initiate cpu frequency transitions from the scheduler.

This patch implements a simple function to return the CPUfreq driver
flags. While currently the flags are a u8, that could grow at a future
date and cpufreq_driver_get_flags returns an int. Additionally the
function needs to return an error in case no driver is registered.

Signed-off-by: Mike Turquette <mturquette@xxxxxxxxxx>
---
drivers/cpufreq/cpufreq.c | 9 +++++++++
1 file changed, 9 insertions(+)

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 9b471b2..f3b9042 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1980,6 +1980,15 @@ int cpufreq_driver_target(struct cpufreq_policy *policy,
}
EXPORT_SYMBOL_GPL(cpufreq_driver_target);

+int cpufreq_driver_get_flags(void)
+{
+ if (!cpufreq_driver)
+ return -ENODEV;
+
+ return cpufreq_driver->flags;
+}
+EXPORT_SYMBOL_GPL(cpufreq_driver_get_flags);
+
/*
* when "event" is CPUFREQ_GOV_LIMITS
*/
--
1.8.3.2

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