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path: root/drivers/cpufreq/arm_big_little_dt.c
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2013-05-22cpufreq: arm_big_little_dt: Instantiate as platform_driverViresh Kumar
As multiplatform build is being adopted by more and more ARM platforms, initcall function should be used very carefully. For example, when both arm_big_little_dt and cpufreq-cpu0 drivers are compiled in, arm_big_little_dt driver may try to register even if we had platform device for cpufreq-cpu0 registered. To eliminate this undesired the effect, the patch changes arm_big_little_dt driver to have it instantiated as a platform_driver. Then it will only run on platforms that create the platform_device "arm-bL-cpufreq-dt". Reported-and-tested-by: Rob Herring <robherring2@gmail.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-05-22cpufreq: arm_big_little_dt: Register driver only if DT has valid dataViresh Kumar
If arm_big_little_dt driver is enabled, then it will always try to register with big LITTLE cpufreq core driver. In case DT doesn't have relevant data for cpu nodes, i.e. operating points aren't present, then we should exit early and shouldn't register with big LITTLE cpufreq core driver. Otherwise we will fail continuously from the driver->init() routine. This patch fixes this issue. Reported-and-tested-by: Jon Medhurst <tixy@linaro.org> Reviewed-by: Jon Medhurst <tixy@linaro.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-05-12cpufreq: ARM big LITTLE DT: Return CPUFREQ_ETERNAL if clock-latency isn't foundViresh Kumar
If "/cpus" node isn't present or "clock-latency" isn't defined we are returning error currently. Let's return CPUFREQ_ETERNAL instead, so that we don't fail. Flag appropriate messages to user in such cases. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-05-12cpufreq: ARM big LITTLE DT: Return correct transition latencyViresh Kumar
By mistake we are returning zero for successful call to dt_get_transition_latency(), whereas we should return transition_latency. Fix that. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-04-22cpufreq: ARM big LITTLE: put DT nodes after using themViresh Kumar
DT nodes should be put using of_node_put() to balance their usage counts. This is not done properly in ARM's big LITTLE driver. Fix it. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-04-02cpufreq: ARM big LITTLE: Add generic cpufreq driver and its DT glueViresh Kumar
big LITTLE is ARM's new Architecture focussing power/performance needs of modern world. More information about big LITTLE can be found here: http://www.arm.com/products/processors/technologies/biglittleprocessing.php http://lwn.net/Articles/481055/ In order to keep cpufreq support for all big LITTLE platforms simple/generic, this patch tries to add a generic cpufreq driver layer for all big LITTLE platforms. The driver is divided into two parts: - Core driver: Generic and shared across all big LITTLE SoC's - Glue drivers: Per platform drivers providing ops to the core driver This patch adds in a generic glue driver which would extract information from Device Tree. Future SoC's can either reuse the DT glue or write their own depending on the need. Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>