From 7b4050381127ae11fcfc74a106d715a5fbbf888a Mon Sep 17 00:00:00 2001 From: MyungJoo Ham Date: Thu, 14 Jul 2011 10:33:55 +0900 Subject: PM/Devfreq: Add Exynos4-bus device DVFS driver for Exynos4210/4212/4412. Exynos4-bus device devfreq driver add DVFS capability for Exynos4210/4212/4412-Bus (memory). The driver monitors PPMU counters of memory controllers and adjusts operating frequencies and voltages with OPP. For Exynos4210, vdd_int is controlled. For exynos4412/4212, vdd_mif and vdd_int are controlled. Dependency (CONFIG_EXYNOS_ASV): Exynos4 ASV driver has been posted in the mailing list; however, it si not yet upstreamed. Although the current revision of Exynos4 ASV patch does not contain "CONFIG_EXYNOS_ASV", we have added the symbol to hide the dependent from compilers for now. As soon as Exynos4 ASV drivers are merged, the #ifdef statement will be removed or the name will be changed. However, enabling ASV is essential in most Exynos4 chips to reduce the power consumption of Exynos4210 because without ASV, this Devfreq driver assumes the worst case scenario, which consumes more power. Signed-off-by: MyungJoo Ham Signed-off-by: Kyungmin Park --- Changes from v1 - Support 4212 and 4412 as well as 4210. --- drivers/devfreq/Kconfig | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'drivers/devfreq/Kconfig') diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig index 8f0491037080..464fa2147dfb 100644 --- a/drivers/devfreq/Kconfig +++ b/drivers/devfreq/Kconfig @@ -65,4 +65,17 @@ config DEVFREQ_GOV_USERSPACE comment "DEVFREQ Drivers" +config ARM_EXYNOS4_BUS_DEVFREQ + bool "ARM Exynos4210/4212/4412 Memory Bus DEVFREQ Driver" + depends on CPU_EXYNOS4210 || CPU_EXYNOS4212 || CPU_EXYNOS4412 + select ARCH_HAS_OPP + select DEVFREQ_GOV_SIMPLE_ONDEMAND + help + This adds the DEVFREQ driver for Exynos4210 memory bus (vdd_int) + and Exynos4212/4412 memory interface and bus (vdd_mif + vdd_int). + It reads PPMU counters of memory controllers and adjusts + the operating frequencies and voltages with OPP support. + To operate with optimal voltages, ASV support is required + (CONFIG_EXYNOS_ASV). + endif # PM_DEVFREQ -- cgit v1.2.2