From: Nishanth Menon Date: Tue, 9 Apr 2013 23:22:01 +0000 (+0000) Subject: cpufreq: OMAP: instantiate omap-cpufreq as a platform_driver X-Git-Tag: omap-for-v3.10/dt-fixes-for-merge-window~92^2~1^2~11 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=49ded525d4486dc97fc965858bf3ddf245463670;p=pandora-kernel.git cpufreq: OMAP: instantiate omap-cpufreq as a platform_driver As multi-platform build is being adopted by more and more ARM platforms, initcall function should be used very carefully. For example, when CONFIG_ARM_OMAP2PLUS_CPUFREQ is built in the kernel, omap_cpufreq_init() will be called on all the platforms to initialize omap-cpufreq driver. Further, on OMAP, we now use Soc generic cpufreq-cpu0 driver using device tree entries. To allow cpufreq-cpu0 and omap-cpufreq drivers to co-exist for OMAP in a single image, we need to ensure the following: 1. With device tree boot, we use cpufreq-cpu0 2. With non device tree boot, we use omap-cpufreq In the case of (1), we will have cpu OPPs and regulator registered as part of the device tree nodes, to ensure that omap-cpufreq and cpufreq-cpu0 don't conflict in managing the frequency of the same CPU, we should not permit omap-cpufreq to be probed. In the case of (2), we will not have the cpufreq-cpu0 device, hence only omap-cpufreq will be active. To eliminate this undesired these effects, we change omap-cpufreq driver to have it instantiated as a platform_driver and register "omap-cpufreq" device only when booted without device tree nodes on OMAP platforms. This allows the following: a) Will only run on platforms that create the platform_device "omap-cpufreq". b) Since the platform_device is registered only when device tree nodes are *not* populated, omap-cpufreq driver does not conflict with the usage of cpufreq-cpu0 driver which is used on OMAP platforms when device tree nodes are present. Inspired by commit 5553f9e26f6f49a93ba732fd222eac6973a4cf35 (cpufreq: instantiate cpufreq-cpu0 as a platform_driver) [robherring2@gmail.com: reported conflict of omap-cpufreq vs other driver in an non-device tree supported boot] Reported-by: Rob Herring Signed-off-by: Nishanth Menon Acked-by: Viresh Kumar Signed-off-by: Kevin Hilman Signed-off-by: Rafael J. Wysocki --- Reading git-diff-tree failed