Hello, I am working on trying to enable power management features on a product that was based on the OMAP4430 SoC and the mainline 3.14 kernel. In particular, I am interested in enabling Smart Reflex/AVS and frequency scaling (via cpufreq) functionality.
I have attempted to use the following kernel configuration additions: CONFIG_CPU_FREQ CONFIG_POWER_AVS_OMAP CONFIG_ARM_OMAP2PLUS_CPUFREQ or CONFIG_GENERIC_CPUFREQ_CPU0 CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE CONFIG_CPU_FREQ_GOV_COMMON CONFIG_CPU_FREQ_GOV_CONSERVATIVE CONFIG_CPU_FREQ_GOV_ONDEMAND CONFIG_CPU_FREQ_GOV_PERFORMANCE CONFIG_CPU_FREQ_GOV_POWERSAVE CONFIG_CPU_FREQ_GOV_USERSPACE CONFIG_CPU_FREQ_STAT CONFIG_POWER_AVS_OMAP_CLASS3 However, I don't get the expected sysfs nodes for cpufreq, and omapconf (via "omapconf show sr") reports "All Smart-Reflex Modules disabled." During kernel boot, I also see the following output which might or might not be related to the problem: ARM PMU: not yet supported on OMAP4430 due to missing CTI driver OMAP4 PM: u-boot >= v2012.07 is required for full PM support sr_init: No PMIC hook to init smartreflex sr_init: platform driver register failed for SR In addition, if I attempt to use CONFIG_GENERIC_CPUFREQ_CPU0 instead of CONFIG_ARM_OMAP2PLUS_CPUFREQ, I also get the following output: cpufreq_cpu0: failed to get cpu0 regulator: -19 cpufreq_cpu0: failed to get cpu0 clock: -2 cpufreq-cpu0: probe of cpufreq-cpu0.0 failed with error -2 I have also tried out the latest in the linux-3.14.y branch of the ti-linux-kernel fork [1], thinking that OMAP power management might be better supported there, but similarly did not see any indication of cpufreq or Smart Reflex functioning. My question, then, is whether power management is expected to work for OMAP4430 under Linux 3.14, or whether there might be issues on my end? Perhaps I am missing something in the device tree, or maybe my bootloader isn't setting up something the kernel expects (I'm using a pretty minimal custom bootloader). If OMAP4 power management is not supported in the mainline or TI 3.14 kernels, is there another/later kernel that has this support? I was hoping to stick with 3.14 because I don't want regressions in the project due to major kernel updates, but I would be willing to see what happens with a newer kernel if it supports power management. I had been looking at a few older threads ([2], [3], [4]) that deal with this, but it was unclear whether/when such support was upstreamed. Thank you. [1] https://git.ti.com/ti-linux-kernel/ti-linux-kernel/commits/linux-3.14.y [2] http://www.spinics.net/lists/linux-omap/msg102038.html [3] http://lists.infradead.org/pipermail/linux-arm-kernel/2013-November/212472.html [4] https://bugzilla.kernel.org/show_bug.cgi?id=58541 ___________ Frank Jenner -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
