Re: [PATCH 1/2] ARM: clps711x: Add cpuidle driver

[Daniel Lezcano <daniel.lezcano@linaro.org>]

On 03/22/2014 06:44 AM, Alexander Shiyan wrote:
> Add cpuidle support for ARM Cirrus Logic CLPS711X CPUs.
> This CPU has an unique internal register and write to this location
> will put the system into the Idle State by halting the clock to the
> processor until an interrupt is generated.
>
> Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
> ---
>   drivers/cpuidle/Kconfig.arm        |  6 ++++
>   drivers/cpuidle/Makefile           |  1 +
>   drivers/cpuidle/cpuidle-clps711x.c | 64 ++++++++++++++++++++++++++++++++++++++
>   3 files changed, 71 insertions(+)
>   create mode 100644 drivers/cpuidle/cpuidle-clps711x.c
>
> diff --git a/drivers/cpuidle/Kconfig.arm b/drivers/cpuidle/Kconfig.arm
> index 97ccc31..371e75d 100644
> --- a/drivers/cpuidle/Kconfig.arm
> +++ b/drivers/cpuidle/Kconfig.arm
> @@ -13,6 +13,12 @@ config ARM_BIG_LITTLE_CPUIDLE
>   	  define different C-states for little and big cores through the
>   	  multiple CPU idle drivers infrastructure.
>
> +config ARM_CLPS711X_CPUIDLE
> +	bool "CPU Idle Driver for CLPS711X processors"
> +	depends on ARCH_CLPS711X || COMPILE_TEST
> +	help
> +	  Select this to enable cpuidle on Cirrus Logic CLPS711X SOCs.
> +
>   config ARM_HIGHBANK_CPUIDLE
>   	bool "CPU Idle Driver for Calxeda processors"
>   	depends on ARM_PSCI
> diff --git a/drivers/cpuidle/Makefile b/drivers/cpuidle/Makefile
> index f71ae1b..534fff5 100644
> --- a/drivers/cpuidle/Makefile
> +++ b/drivers/cpuidle/Makefile
> @@ -8,6 +8,7 @@ obj-$(CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED) += coupled.o
>   ##################################################################################
>   # ARM SoC drivers
>   obj-$(CONFIG_ARM_BIG_LITTLE_CPUIDLE)	+= cpuidle-big_little.o
> +obj-$(CONFIG_ARM_CLPS711X_CPUIDLE)	+= cpuidle-clps711x.o
>   obj-$(CONFIG_ARM_HIGHBANK_CPUIDLE)	+= cpuidle-calxeda.o
>   obj-$(CONFIG_ARM_KIRKWOOD_CPUIDLE)	+= cpuidle-kirkwood.o
>   obj-$(CONFIG_ARM_ZYNQ_CPUIDLE)		+= cpuidle-zynq.o
> diff --git a/drivers/cpuidle/cpuidle-clps711x.c b/drivers/cpuidle/cpuidle-clps711x.c
> new file mode 100644
> index 0000000..5243811
> --- /dev/null
> +++ b/drivers/cpuidle/cpuidle-clps711x.c
> @@ -0,0 +1,64 @@
> +/*
> + *  CLPS711X CPU idle driver
> + *
> + *  Copyright (C) 2014 Alexander Shiyan <shc_work@mail.ru>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + */
> +
> +#include <linux/cpuidle.h>
> +#include <linux/err.h>
> +#include <linux/io.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +
> +#define CLPS711X_CPUIDLE_NAME	"clps711x-cpuidle"
> +
> +static void __iomem *clps711x_halt;
> +
> +static int clps711x_cpuidle_halt(struct cpuidle_device *dev,
> +				 struct cpuidle_driver *drv, int index)
> +{
> +	writel(0xaa, clps711x_halt);
> +
> +	return index;
> +}
> +
> +static struct cpuidle_driver clps711x_idle_driver = {
> +	.name		= CLPS711X_CPUIDLE_NAME,
> +	.owner		= THIS_MODULE,
> +	.states[0]	= {
> +		.name		= "HALT",
> +		.desc		= "CLPS711X HALT",
> +		.enter		= clps711x_cpuidle_halt,
> +		.exit_latency	= 1,

Did you forget target_residency ? Or just not defined it as it is 0 ?

> +	},
> +	.state_count	= 1,
> +};
> +
> +static int __init clps711x_cpuidle_probe(struct platform_device *pdev)
> +{
> +	struct resource *res;
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	clps711x_halt = devm_ioremap_resource(&pdev->dev, res);
> +	if (IS_ERR(clps711x_halt))
> +		return PTR_ERR(clps711x_halt);
> +
> +	return cpuidle_register(&clps711x_idle_driver, NULL);
> +}
> +
> +static struct platform_driver clps711x_cpuidle_driver = {
> +	.driver	= {
> +		.name	= CLPS711X_CPUIDLE_NAME,
> +		.owner	= THIS_MODULE,
> +	},
> +};
> +module_platform_driver_probe(clps711x_cpuidle_driver, clps711x_cpuidle_probe);
> +
> +MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
> +MODULE_DESCRIPTION("CLPS711X CPU idle driver");
> +MODULE_LICENSE("GPL");
>


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