From 9f14da345599c14b329cf5ac9499ad322056dd32 Mon Sep 17 00:00:00 2001 From: Lorenzo Pieralisi Date: Fri, 14 Feb 2014 14:28:39 +0000 Subject: drivers: cpuidle: implement DT based idle states infrastructure On most common ARM systems, the low-power states a CPU can be put into are not discoverable in HW and require device tree bindings to describe power down suspend operations and idle states parameters. In order to enable DT based idle states and configure idle drivers, this patch implements the bulk infrastructure required to parse the device tree idle states bindings and initialize the corresponding CPUidle driver states data. The parsing API accepts a start index that defines the first idle state that should be initialized by the parsing code in order to give new and legacy driver flexibility over which states should be parsed using the new DT mechanism. The idle states node(s) is obtained from the phandle list of the first cpu in the driver cpumask; the kernel checks that the idle state node phandle is the same for all CPUs in the driver cpumask before declaring the idle state as valid and start parsing its content. The idle state enter function pointer is initialized through DT match structures passed in by the CPUidle driver, so that ARM legacy code can cope with platform specific idle entry method based on compatible string matching and the code used to initialize the enter function pointer can be moved to the DT generic layer. Acked-by: Catalin Marinas Acked-by: Daniel Lezcano Signed-off-by: Lorenzo Pieralisi Signed-off-by: Daniel Lezcano --- drivers/cpuidle/Kconfig | 3 +++ 1 file changed, 3 insertions(+) (limited to 'drivers/cpuidle/Kconfig') diff --git a/drivers/cpuidle/Kconfig b/drivers/cpuidle/Kconfig index 32748c36c477..8deb934c6356 100644 --- a/drivers/cpuidle/Kconfig +++ b/drivers/cpuidle/Kconfig @@ -25,6 +25,9 @@ config CPU_IDLE_GOV_MENU bool "Menu governor (for tickless system)" default y +config DT_IDLE_STATES + bool + menu "ARM CPU Idle Drivers" depends on ARM source "drivers/cpuidle/Kconfig.arm" -- cgit v1.2.3 From 3299b63de384159579143d4abdfb94013e0b5470 Mon Sep 17 00:00:00 2001 From: Lorenzo Pieralisi Date: Fri, 28 Feb 2014 13:03:44 +0000 Subject: drivers: cpuidle: CPU idle ARM64 driver This patch implements a generic CPU idle driver for ARM64 machines. It relies on the DT idle states infrastructure to initialize idle states count and respective parameters. Current code assumes the driver is managing idle states on all possible CPUs but can be easily generalized to support heterogenous systems and build cpumasks at runtime using MIDRs or DT cpu nodes compatible properties. The driver relies on the arm64 CPU operations to call the idle initialization hook used to parse and save suspend back-end specific idle states information upon probing. Idle state index 0 is always initialized as a simple wfi state, ie always considered present and functional on all ARM64 platforms. Idle state indices higher than 0 trigger idle state entry by calling the cpu_suspend function, that triggers the suspend operation through the CPU operations suspend back-end hook. cpu_suspend passes the idle state index as a parameter so that the CPU operations suspend back-end can retrieve the required idle state data by using the idle state index to execute a look-up on its internal data structures. Reviewed-by: Ashwin Chaugule Reviewed-by: Catalin Marinas Signed-off-by: Lorenzo Pieralisi Signed-off-by: Daniel Lezcano --- drivers/cpuidle/Kconfig | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'drivers/cpuidle/Kconfig') diff --git a/drivers/cpuidle/Kconfig b/drivers/cpuidle/Kconfig index 8deb934c6356..c5029c1209b4 100644 --- a/drivers/cpuidle/Kconfig +++ b/drivers/cpuidle/Kconfig @@ -33,6 +33,11 @@ depends on ARM source "drivers/cpuidle/Kconfig.arm" endmenu +menu "ARM64 CPU Idle Drivers" +depends on ARM64 +source "drivers/cpuidle/Kconfig.arm64" +endmenu + menu "MIPS CPU Idle Drivers" depends on MIPS source "drivers/cpuidle/Kconfig.mips" -- cgit v1.2.3