[PATCH v8 8/8] drivers: cpuidle: initialize Exynos driver through DT

Daniel Lezcano daniel.lezcano at linaro.org
Wed Sep 3 06:32:14 PDT 2014


On 09/01/2014 05:28 PM, Lorenzo Pieralisi wrote:
> With the introduction of DT based idle states, CPUidle drivers for
> ARM can now initialize idle states data through properties in the device
> tree.
>
> This patch adds code to the Exynos CPUidle driver to dynamically
> initialize idle states data through the updated device tree source
> files.
>
> Cc: Chander Kashyap <k.chander at samsung.com>
> Cc: Kukjin Kim <kgene.kim at samsung.com>
> Cc: Tomasz Figa <t.figa at samsung.com>
> Acked-by: Catalin Marinas <catalin.marinas at arm.com>
> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi at arm.com>

Acked-by: Daniel Lezcano <daniel.lezcano at linaro.org>

> ---
>   arch/arm/boot/dts/exynos4210.dtsi | 11 +++++++++++
>   arch/arm/boot/dts/exynos5250.dtsi | 11 +++++++++++
>   drivers/cpuidle/Kconfig.arm       |  1 +
>   drivers/cpuidle/cpuidle-exynos.c  | 18 +++++++++++++++++-
>   4 files changed, 40 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm/boot/dts/exynos4210.dtsi b/arch/arm/boot/dts/exynos4210.dtsi
> index eab7c7b..69fd1a0 100644
> --- a/arch/arm/boot/dts/exynos4210.dtsi
> +++ b/arch/arm/boot/dts/exynos4210.dtsi
> @@ -48,12 +48,23 @@
>   			device_type = "cpu";
>   			compatible = "arm,cortex-a9";
>   			reg = <0x900>;
> +			cpu-idle-states = <&CLUSTER_SLEEP_0>;
>   		};
>
>   		cpu at 901 {
>   			device_type = "cpu";
>   			compatible = "arm,cortex-a9";
>   			reg = <0x901>;
> +			cpu-idle-states = <&CLUSTER_SLEEP_0>;
> +		};
> +
> +		idle-states {
> +			CLUSTER_SLEEP_0: cluster-sleep-0 {
> +				compatible = "arm,idle-state";
> +				entry-latency-us = <1000>;
> +				exit-latency-us = <300>;
> +				min-residency-us = <100000>;
> +			};
>   		};
>   	};
>
> diff --git a/arch/arm/boot/dts/exynos5250.dtsi b/arch/arm/boot/dts/exynos5250.dtsi
> index 492e1ef..3a758ff 100644
> --- a/arch/arm/boot/dts/exynos5250.dtsi
> +++ b/arch/arm/boot/dts/exynos5250.dtsi
> @@ -63,12 +63,23 @@
>   			compatible = "arm,cortex-a15";
>   			reg = <0>;
>   			clock-frequency = <1700000000>;
> +			cpu-idle-states = <&CLUSTER_SLEEP_0>;
>   		};
>   		cpu at 1 {
>   			device_type = "cpu";
>   			compatible = "arm,cortex-a15";
>   			reg = <1>;
>   			clock-frequency = <1700000000>;
> +			cpu-idle-states = <&CLUSTER_SLEEP_0>;
> +		};
> +
> +		idle-states {
> +			CLUSTER_SLEEP_0: cluster-sleep-0 {
> +				compatible = "arm,idle-state";
> +				entry-latency-us = <1000>;
> +				exit-latency-us = <300>;
> +				min-residency-us = <100000>;
> +			};
>   		};
>   	};
>
> diff --git a/drivers/cpuidle/Kconfig.arm b/drivers/cpuidle/Kconfig.arm
> index e339c7f..04cc229 100644
> --- a/drivers/cpuidle/Kconfig.arm
> +++ b/drivers/cpuidle/Kconfig.arm
> @@ -55,6 +55,7 @@ config ARM_AT91_CPUIDLE
>   config ARM_EXYNOS_CPUIDLE
>   	bool "Cpu Idle Driver for the Exynos processors"
>   	depends on ARCH_EXYNOS
> +	select DT_IDLE_STATES
>   	help
>   	  Select this to enable cpuidle for Exynos processors
>
> diff --git a/drivers/cpuidle/cpuidle-exynos.c b/drivers/cpuidle/cpuidle-exynos.c
> index ba9b34b..e66a426 100644
> --- a/drivers/cpuidle/cpuidle-exynos.c
> +++ b/drivers/cpuidle/cpuidle-exynos.c
> @@ -18,6 +18,8 @@
>   #include <asm/suspend.h>
>   #include <asm/cpuidle.h>
>
> +#include "dt_idle_states.h"
> +
>   static void (*exynos_enter_aftr)(void);
>
>   static int exynos_enter_lowpower(struct cpuidle_device *dev,
> @@ -56,13 +58,27 @@ static struct cpuidle_driver exynos_idle_driver = {
>   	.safe_state_index = 0,
>   };
>
> +static const struct of_device_id exynos_idle_state_match[] __initconst = {
> +	{ .compatible = "arm,idle-state",
> +	  .data = exynos_enter_lowpower },
> +	{ },
> +};
> +
>   static int exynos_cpuidle_probe(struct platform_device *pdev)
>   {
>   	int ret;
> +	struct cpuidle_driver *drv = &exynos_idle_driver;
>
>   	exynos_enter_aftr = (void *)(pdev->dev.platform_data);
>
> -	ret = cpuidle_register(&exynos_idle_driver, NULL);
> +	/* Start at index 1, index 0 standard WFI */
> +	ret = dt_init_idle_driver(drv, exynos_idle_state_match, 1);
> +	if (ret < 0) {
> +		dev_err(&pdev->dev, "failed to initialize idle states\n");
> +		return ret;
> +	}
> +
> +	ret = cpuidle_register(drv, NULL);
>   	if (ret) {
>   		dev_err(&pdev->dev, "failed to register cpuidle driver\n");
>   		return ret;
>


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